CN204262323U - A kind of aluminium alloy gear box casing die casting deep hole core structure - Google Patents

Abstract

The utility model discloses a deep-hole core structure of an aluminum alloy gearbox casing die-casting mold, which comprises a die-casting mold. A core cavity is arranged on the die-casting mold corresponding to the position of the deep hole in the mold cavity, and a core is arranged in the core cavity. The mold, the core cavity includes a mating section inner cavity with a smaller diameter at the inner end and an active segment inner cavity with a larger diameter at the outer end, and the core mold includes a cavity at the inner end for forming the deep hole shape of the gearbox case. The core of the forming section, the core mold also includes a matching section core and a movable section core connected in sequence behind the forming section core, and the matching section core is a straight bar section whose diameter is the same as that of the rear end of the forming section core , a sealing fit is formed between the core of the matching section and the inner cavity of the matching section, and the core of the movable section is a straight rod section whose diameter is larger than that of the core of the matching section. The utility model has the advantages of being able to protect the core mold, making it difficult to break and damage, improving the service life, etc., ensuring the smoothness of the die-casting mold, and indirectly improving the working efficiency of the mold.

Description

A deep-hole core structure of an aluminum alloy gearbox housing die-casting mold

technical field

The utility model relates to a die-casting auxiliary tool for an automobile engine gearbox case, in particular to a deep-hole core structure of an aluminum alloy gearbox case die-casting mold.

Background technique

Die casting (full name: pressure casting) refers to the casting method of filling the mold cavity with molten alloy under high pressure and high speed conditions, and cooling and forming under high pressure. It is the most widely used and fastest developing metal thermal processing in the casting process. One of the forming process methods.

The car engine gearbox is the box used to install the gearbox on the car. The transmission is used to change the rotation of the engine crankshaft by changing the transmission ratio, so as to meet the different requirements for driving wheel traction and vehicle speed under different driving conditions such as starting, accelerating, driving, and overcoming various road obstacles.

When producing such a gearbox housing, die castings are generally obtained by die-casting an aluminum alloy. In the die-casting mold used, in order to form some deep-hole structures such as installation holes and process holes on the gearbox, it is necessary to set a deep-hole core structure that can pull cores in the mold to facilitate die-casting demoulding. The existing deep-hole core structure, as shown in Figure 1-3, includes a die-casting mold 1, a core cavity is provided on the die-casting mold 1 corresponding to the position of the deep hole in the mold cavity 2, and a core mold is arranged in the core cavity , the core cavity includes a mating section inner cavity 3 with a smaller diameter at the inner end and an active segment inner cavity 4 with a larger diameter at the outer end, and the core mold includes a deep hole shape for forming a gearbox casing at the inner end The forming section core 5 and the matching section core 6 with a larger diameter at the outer end, wherein the forming section core 5 is a truncated cone with a surface slope to facilitate demoulding, the forming section core 5 and the matching section core 6 The step at the joint is just at the outlet of the inner cavity 3 of the mating section, and a sealed fit is formed between the front half of the core 6 of the mating section and the inner cavity 3 of the mating section to prevent leakage of the casting liquid, and the second half of the core 6 of the mating section and the movable section A movable space is formed between the inner cavities 4 to facilitate the drafting of the core mold.

But this existing die-casting mold deep-hole core structure has the following defects: 1, adopt this die-casting mold deep-hole core structure, because the forming section core 5 of the core mold has a taper and usually adopts turning molding, Therefore, a chamfering step will appear at the junction of the root of the forming segment core 5 and the mating segment core 6 . Since the chamfered step is processed by turning, there are turning marks on the surface of the step. Due to the fast metal flow rate and high pressure in the cavity during die-casting, it is easy to generate stress concentration at the step during filling and solidification, and it is easy to cause cracks in this part when it is heated and cooled repeatedly. Thus making the core invalid. 2. During the die-casting process, the core 5 of the forming section is wrapped in molten aluminum. During the solidification process, the molten aluminum will have a deflection effect on the core due to thermal stress. In the case of repeated deflection, the core of the forming section will 5. It is very easy to break, and it takes more than 4 hours to restore a broken core mold, which has a great impact on production.

Utility model content

Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the utility model is: how to provide a deep-hole core structure of an aluminum alloy gearbox casing die-casting mold with a long service life and not easy to break.

In order to solve the above technical problems, the utility model adopts the following technical solutions:

A deep hole core structure of an aluminum alloy gearbox housing die-casting mold, comprising a die-casting mold, a core cavity is arranged on the die-casting mold corresponding to the position of the deep hole in the mold cavity, a core mold is arranged in the core cavity, and a core cavity It includes a mating section inner cavity with a smaller diameter at the inner end and an active segment inner cavity with a larger diameter at the outer end. The core mold includes a forming section core at the inner end for forming the shape of the deep hole of the gearbox housing. The core of the forming section is a truncated cone with a surface slope, and it is characterized in that the core mold also includes a matching section core and a movable section core successively connected behind the forming section core, and the matching section core is a diameter and The straight rod section with the same diameter at the rear end of the core of the forming section makes a smooth transition connection between the front surface of the core of the matching section and the rear surface of the core of the forming section, and a sealed fit is formed between the core of the matching section and the inner cavity of the matching section. The section core is a straight rod section whose diameter is larger than that of the mating section core, and an activity space is formed between the movable section core and the movable section inner cavity to facilitate the drawing of the core mold.

In the utility model, the diameter of the core of the matching section in the core mold is reduced to make it the same diameter as the rear end of the forming section core, so that a smooth transition is formed between the matching section core and the forming section core at the front end, and at the same time The diameter of the inner cavity of the matching section in the core cavity is reduced, so that there is no chamfering step in the core mold at the outlet of the inner cavity of the matching section. In this way, there will be no concentrated turning marks when the core mold is turned, reducing the In the subsequent use, the core tends to crack; in addition, due to the direct smooth transition, the rigidity of the core structure is increased, and the anti-deflection effect of aluminum water on the core during the solidification process is increased, which greatly reduces the stress concentration effect of the core. Secondly, the larger-diameter active section core set at the back end of the core mold is connected with the mating section core to hide the steps inside the mold. The overall structure of the core mold is still transitioned from thick to thin, which not only ensures The overall rigidity of the core mold can also make the core mold easier to demould.

As an optimization, the junction between the core of the mating section and the core of the active section is in the shape of a truncated cone and is located in the inner cavity of the active section. In this way, the interference between the step in the core mold and the step in the core cavity can be avoided, and it is more convenient to demould the core mold. It is verified by experiments that the utility model can prolong the service life of the core mold by more than 5 times.

To sum up, the utility model has the advantages of being able to protect the core mold so that it is not easy to be broken and damaged, and has a long service life, which ensures the smoothness of the die-casting mold and indirectly improves the working efficiency of the mold.

Description of drawings

FIG. 1 is a schematic structural view of an existing die-casting mold for an aluminum alloy transmission case.

Fig. 2 is the A-A view of Fig. 1, in which the deep hole core structure can be schematically shown.

Fig. 3 is an enlarged schematic view of the circled part in Fig. 2, that is, the position of a single deep hole core structure.

Fig. 4 is a schematic structural view of the die-casting mold for an aluminum alloy transmission case of the present invention.

Fig. 5 is a view of A-A of Fig. 4, in which the deep hole core structure of the present invention can be schematically shown.

FIG. 6 is an enlarged schematic view of the circled area in FIG. 5 , that is, the location of a single deep-hole core structure.

Detailed ways

The utility model will be further described in detail below in conjunction with specific embodiments.

For specific implementation: as shown in Figure 4-Figure 6, a deep hole core structure of an aluminum alloy gearbox housing die-casting mold includes a die-casting mold 1, and a die-casting mold 1 is provided with a molded hole at the position corresponding to the deep hole in the mold cavity 2. Core cavity, the core cavity is provided with a core mold, the core cavity includes a matching section inner cavity 3 with a smaller diameter at the inner end and an active segment inner cavity 4 with a larger diameter at the outer end, the core mold includes a The forming section core 5 used to form the shape of the deep hole of the gearbox casing at the end is a truncated cone shape with a surface slope, wherein the core mold also includes Matching segment core 6 and movable segment core 7, said matching segment core 6 is a straight rod section with the same diameter as the rear end diameter of forming segment core 5 so that the front end surface of matching segment core 6 and the rear end of forming segment core 5 The end surface forms a smooth transition connection, and a sealing fit is formed between the mating section core 6 and the mating section inner cavity 3. The movable section core 7 is a straight rod section whose diameter is larger than the mating section core 6, and the movable section core 7 and the mating section inner cavity 3 A movable space is formed between the inner cavities 4 of the movable section to facilitate the drafting of the core mold.

Wherein, the junction between the core 6 of the mating section and the core 7 of the movable section is in the shape of a truncated cone and is located in the inner cavity 4 of the movable section. In this way, the interference between the step in the core mold and the step in the core cavity can be avoided, and it is more convenient to demould the core mold.

In the utility model, the diameter of the matching section core 6 in the core mold is reduced so that it is the same as the diameter of the rear end of the forming section core 5, so that a smooth transition is formed between the matching section core and the forming section core at the front end, At the same time, the diameter of the matching section inner cavity 3 in the core cavity is also reduced, so that there is no chamfering step in the core mold at the exit position of the matching section inner cavity 3, so that the core mold will not be concentrated when turning. Turning marks reduce the cracking tendency of the core in subsequent use; in addition, due to the direct smooth transition, the rigidity of the core structure is increased, and the bending resistance of the aluminum water to the core during the solidification process is increased, which greatly reduces the stress of the core concentration effect. Secondly, the larger-diameter active section core set at the rear end of the core mold is connected with the matching section core 6, and the steps are hidden inside the mold. The overall structure of the core mold is still a transition from thick to thin, which not only ensures The overall rigidity of the core mold is improved, and it can also make the core mold easier to demould. It is verified by experiments that the utility model can prolong the service life of the core mold by more than 5 times.

To sum up, the utility model has the advantages of being able to protect the core mold so that it is not easy to be broken and damaged, and has a long service life, which ensures the smoothness of the die-casting mold and indirectly improves the working efficiency of the mold.

Claims (2)

1. an aluminium alloy gear box casing die casting deep hole core structure, comprise die casting, on die casting, corresponding mold cavity medium-length hole position is provided with core chamber, core mould is provided with in core chamber, core chamber comprises and is positioned at inner end and the less cooperation section inner chamber of diameter and be positioned at the larger active segment inner chamber of outer diameter, core mould comprises the shaped segment core for the gear box casing deep hole shape that is shaped being positioned at inner end, shaped segment core is the taper type with surfaces slope, it is characterized in that, core mould also comprises the cooperation segment type core and active segment core that are engaged on shaped segment core rear successively, described cooperation segment type core is that the straight bar section that diameter is identical with shaped segment core rear end diameter makes to coordinate segment type core front-end surface and the formation of shaped segment core rear end surface to seamlessly transit linking, formed between cooperation segment type core and cooperation section inner chamber and be sealed and matched, described active segment core is that diameter is greater than the straight bar section of cooperation segment type core and forms activity space between active segment core and active segment inner chamber with convenience type core withdrawing pattern.

2. aluminium alloy gear box casing die casting deep hole core structure as claimed in claim 1, it is characterized in that, the joining place between described cooperation segment type core and active segment core is taper type and is positioned at active segment inner chamber.