CN110475631B - Casting device - Google Patents

Abstract

In a casting device, when mold clamping is performed, a cavity (16), an overflow part (34), and a cooling exhaust part (30) (a gas exhaust part (30)) are formed by a fixed mold (12) and a movable mold (10) which are molds. The cooling and exhausting section (30) communicates with the cavity (16) via an overflow section (34). The overflow part (34) has melt-filled parts (38, 40) extending in a direction orthogonal to the joint surface of the fixed mold (12) and the movable mold (10).

Description

Casting device

Technical Field

The present invention relates to a casting apparatus for obtaining a cast product from a cavity formed when a fixed mold and a movable mold are closed.

Background

A cavity of a casting apparatus is filled with a melt (molten metal) of a metal such as aluminum, and the melt is cooled and solidified to obtain a cast product. Here, when the melt is filled into the cavity, air in the cavity may be entrained in the melt. If this occurs, gas defects are formed in the cast product. Therefore, the quality of the cast member is deteriorated.

To avoid this, as described in japanese patent laid-open publication No. 4-157055, for example, in a product portion (a part of a cavity) forming a product, a plurality of overflow runners for overflowing a melt are connected to a final filling portion filled with the melt at the end, and a cooling and exhausting portion (a gas exhausting portion) for exhausting air in the cavity to the atmosphere is provided on the downstream side of the overflow runners. In this case, the air in the cavity is extruded by the melt, and then, is discharged to the atmosphere through the cooling vent.

In such a casting apparatus, it is necessary to avoid the overflowed melt from being discharged from the cooling exhaust portion. From this viewpoint, as described in Japanese patent application laid-open No. 4-157055, a cooling structure is provided in the cooling exhaust unit. This is because the melt reaching the cooling exhaust portion is rapidly solidified by the cooling structure in this case.

Further, as described in japanese utility model registration No. 3077039, it is also effective to provide a plurality of overflow portions having a certain capacity. This is because, in this case, the melt initially enters the mold, and the melt whose temperature has dropped while being entrained in the air in the cavity is accumulated in the overflow portion.

Disclosure of Invention

However, if a cooling structure is provided as described in japanese patent laid-open publication No. 4-157055, or if the capacity of the relief portion is increased or the passage length of the cooling exhaust portion is increased as described in japanese utility model registration No. 3077039, it is not easy to reduce the size and weight of the mold. That is, in the casting apparatus according to the related art, a problem that it is difficult to reduce the cost required for the mold is conspicuous.

The main object of the present invention is to provide a casting apparatus capable of realizing a reduction in size of a cooling exhaust portion by promoting solidification of a melt at a downstream of an overflow portion.

Another object of the present invention is to provide a casting apparatus that can reduce the cost required for a mold by reducing the size and weight of the mold.

According to an embodiment of the present invention, there is provided a casting apparatus having a fixed mold positioned and fixed and a movable mold moving in a direction approaching or away from the fixed mold, a cavity being formed by the fixed mold and the movable mold when mold clamping is performed, wherein a gas discharge portion, an overflow portion, and a melt outlet are formed,

one end of the gas discharge part is communicated with the cavity, and the other end of the gas discharge part is opened to the atmosphere;

the overflow part is arranged between the gas discharge part and the cavity and is used for the melt overflowing from the cavity to enter;

the melt outlet is directed from the mold cavity toward the overflow,

the relief portion extends in a direction orthogonal to a joint surface of the fixed die and the movable die.

The melt overflowing from the cavity enters the melt filling part. The melt-filled portion extends in a direction orthogonal to the joint surface of the fixed mold and the movable mold. Therefore, the entering melt stagnates and is filled. That is, in the present invention, the melt filling portion is provided to secure a space capable of capturing the melt overflowing from the cavity.

After that, the melt is supposed to flow toward the gas discharge portion. That is, in the present invention, the melt can be retained in the overflow portion for a long time. Moreover, the flow velocity of the melt in the overflow is thereby reduced and the temperature is reduced relatively quickly. Therefore, even if the melt reaches the gas discharge portion, the flow velocity is small, the temperature is low, and the amount is small. Thus, when the melt reaches into the gas discharge portion, the melt solidifies rapidly.

Therefore, the gas discharge portion can be miniaturized. Therefore, the mold can be made smaller and lighter, and as a result, the cost required for the mold can be reduced.

In addition, if the melt filling portion is provided in the vicinity of the melt outlet from the cavity, the melt in the vicinity of the melt outlet is kept warm to some extent. Therefore, the so-called riser effect can be maintained.

Preferably: the melt filling parts are respectively arranged on the fixed die and the movable die, and the positions of the melt filling part on the fixed die side and the melt filling part on the movable die side are asymmetric positions. In this configuration, the melt can be caused to flow into one of the melt filling portions and then into the other melt filling portion. That is, the travel path of the melt is increased, and the residence time in the overflow portion is further increased. Therefore, since it is easy to further lower the temperature, the melt at the time of reaching the inside of the gas discharge portion can be further rapidly solidified.

In addition, it is preferable that: a melt outlet from the cavity toward the overflow portion is formed in the joint surface, a communication path for communicating the overflow portion with the gas discharge portion is formed at a position offset in a direction parallel to the joint surface with respect to the melt outlet, and the gas discharge portion is formed along the joint surface.

In this structure, the melt is made to travel while changing its flow direction. As a result, the flow speed decreases, so that the melt can be prevented from overflowing from the mold, so-called flash. In this case, the melt is less likely to flow from the overflow portion to the communicating path. In other words, the melt is liable to be retained in the melt filling portion. Therefore, the melt is made difficult to reach the communicating path, the gas discharge portion, thereby further effectively preventing flash.

The overflow portion may be provided with a melt reservoir portion for temporarily storing the melt overflowing from the cavity, on an upstream side of the melt filling portion. In this case, the capacity of the overflow portion is further increased by the melt reservoir. Further, since the melt is retained in the overflow portion for a further long time, it is difficult for the melt to reach the communicating path and the gas discharge portion, and even if the melt reaches the gas discharge portion, the melt is rapidly solidified as described above.

In this case, the melt outlet may be set such that the width becomes narrower from the cavity toward the overflow. Accordingly, the melt is diffused immediately after entering the overflow. Therefore, since it is difficult to make the melt go straight, it is easy to flow the melt into the melt filling portion.

Preferably: in the case where the width of the melt outlet is narrowed, a gradient is provided in the melt outlet so as to spread from the cavity toward the overflow. By this gradient, the cross-sectional area of the melt outlet can be kept constant even in the case where the width of the melt outlet is made narrow. Therefore, the exhaust speed is made constant.

According to the present invention, the structure is: the overflow portion is interposed between the cavity and the gas discharge portion, into which the melt overflowing from the cavity enters, and includes a melt filling portion extending in a direction orthogonal to a joint surface of the fixed mold and the movable mold.

The melt filling section functions as a space for trapping the entered melt. Therefore, the melt stays in the overflow for a long time. During this time, the flow rate decreases and the temperature drops. Therefore, the flow velocity of the melt reaching the gas discharge portion is small and the temperature is low. Moreover, the amount is small. Therefore, the melt that has reached the gas discharge portion can be rapidly solidified.

Therefore, since the gas discharge portion can be miniaturized, the mold can be miniaturized and lightened. As a result, the cost required for the mold can be reduced.

Drawings

Fig. 1 is a schematic front view of a movable mold constituting a casting apparatus according to an embodiment of the present invention.

Fig. 2 is a schematic plan view of a main part of a movable mold and a fixed mold when clamping the molds.

FIG. 3 is a schematic plan view of the melt outlet from a direction perpendicular to the bonding surface as a viewing angle.

Fig. 4 is a schematic front view of the entire cast product.

Fig. 5 is an enlarged perspective view of a main portion of the casting of fig. 4.

Detailed Description

Hereinafter, a casting apparatus according to the present invention will be described in detail with reference to the accompanying drawings by referring to preferred embodiments.

Fig. 1 is a schematic front view of the entire movable mold 10 constituting the casting apparatus according to the present embodiment, and fig. 2 is a schematic plan view of the main portions of the movable mold 10 and the fixed mold 12 when the molds are closed. The fixed mold 12 is fixed and positioned, and the movable mold 10 is moved in a direction approaching or separating from the fixed mold 12 by a displacement mechanism (e.g., a hydraulic cylinder) not shown. Since this structure is a known structure, detailed description thereof will be omitted.

Two cavity forming portions, not shown, are formed in the fixed mold 12, and two cavity forming portions 14a and 14b are formed in the movable mold 10. When the dies are clamped, the cavity forming portions on the fixed die 12 side and the cavity forming portions 14a and 14b on the movable die 10 side overlap each other, and thereby two cavities 16 shown in fig. 2 are formed. In fig. 2, only the end portion of the cavity 16, in other words, only the most downstream side in the flow direction of the melt L, is shown. In this case, as shown in fig. 4, the cavity 16 is formed into a shape that can obtain the side housings 18a and 18b of the engine for the motorcycle. That is, according to the casting apparatus, two cast products can be obtained by one pouring.

The two cavities 16 communicate with a gate 20 via a runner 19. That is, the melt L introduced from the gate 20 is distributed to the cavity 16 through the runner 19. Therefore, the side shells 18a and 18b are connected by the melt L (hereinafter, referred to as "technical portion" and denoted by reference numeral 22) that is cooled and solidified in the gate 20 and the runner 19.

As shown in fig. 2, a part of the fixed mold 12 is a cavity convex portion 24 protruding toward the movable mold 10, and a portion of the movable mold 10 corresponding to the cavity convex portion 24 is a cavity concave portion 26 recessed. The end of the cavity 16 is formed on the joint surface between the cavity convex portion 24 and the cavity concave portion 26. On the other hand, a cooling exhaust portion 30 (gas discharge portion) is formed on the joint surface between the fixed mold 12 and the flat portion of the movable mold 10. The cooling exhaust portion 30 is formed by opposing the exhaust valley portion 32 formed in the movable mold 10 and the exhaust valley portion 33 of the fixed mold 12.

In the present embodiment, the exhaust valley portions 32 and the exhaust valley portions 33 are formed at six positions, that is, six positions. Therefore, the number of the cooling and exhaust portions 30 and the relief portions 34 described later is also six.

One end of the cooling vent 30 communicates with the end of the cavity 16 via an overflow 34. On the other hand, since the exhaust valley portions 32 and the exhaust valley portions 33 extend to the side surfaces of the movable mold 10, the cooling and exhaust portion 30 is open to the atmosphere at the side surfaces of the fixed mold 12 and the movable mold 10.

The overflow portion 34 has: a melt reservoir 36, a first melt-fill section 38 and a second melt-fill section 40 located on the downstream side of the melt reservoir 36. The melt pool 36 is continuous with the outlet of the cavity 16 and extends toward the base end of the cavity convex portion 24 and the base end of the cavity concave portion 26. That is, the extending direction of the melt pool 36 is orthogonal to the parallel direction along the joint surface.

At the end portion of the cavity 16, a melt outlet 42 formed along the joining surface opens at a substantially middle portion in the longitudinal direction of the melt reservoir 36. Here, as shown in fig. 3 with a direction orthogonal to the joint surface as a view angle, the melt outlet 42 is formed so that the width becomes narrower toward the overflow 34. On the other hand, as can be seen from fig. 2 in which the direction parallel to the joint surface is taken as the view point, a gradient is provided so as to spread toward the overflow 34 at the melt outlet 42. By this gradient, the cross-sectional area of the melt outlet 42 can be maintained substantially constant regardless of narrowing the width. Further, as shown in fig. 2, since the inclined surface is provided on the first melt-filling portion 38 side of the melt outlet 42, most of the melt L discharged from the melt outlet 42 is directed toward the first melt-filling portion 38 as will be described later.

The first melt-filling portion 38 and the second melt-filling portion 40 are portions where the melt L stagnates and cools to solidify, and extend in a direction orthogonal to the joining face. That is, the first melt filling part 38 is a movable mold side melt filling part extending toward the inside of the movable mold 10 away from the joining surface, and the second melt filling part 40 is a fixed mold side melt filling part extending toward the inside of the fixed mold 12 away from the joining surface.

The first melt-filling portion 38 is connected in a straight line to the downstream side of the melt reservoir portion 36. A first bushing 44 against which the first spacer 43 abuts is housed in the first melt filling portion 38, and a first push-out pin 46 is slidably inserted through the first spacer 43 and the first bushing 44. The volume of first melt fill 38 is less than the volume of melt reservoir 36 due to the presence of first liner 44.

The fixed die 12 side of the melt reservoir 36 is bent at substantially 90 ° so as to extend along the joining face. The second melt-filled portion 40 is provided slightly downstream of the bent portion 48, and, as described above, faces the inside of the fixed die 12 away from the joining surface. Thus, the first melt fill portion 38 is not collinear with the second melt fill portion 40. That is, the first melt fill portion 38 and the second melt fill portion 40 are asymmetrically positioned.

A second bushing 52 against which the second spacer 50 abuts is housed in the second melt filling section 40. The second ejector pin 54 is slidably inserted through the second spacer 50 and the second bush 52.

A communication path 56 is formed on the joining surface, the upstream side of which communicates with the second melt-filling portion 40 and the downstream side of which communicates with the cooling vent portion 30. Since the joint surface where the second melt-filling portion 40 and the cooling gas vent portion 30 are formed is recessed from the joint surface of the top surface of the cavity convex portion 24 in plan view, the communication path 56 is located at a position shifted toward the fixed die 12 side with respect to the melt outlet 42.

The casting apparatus according to the present embodiment is basically configured as described above, and the operational effects thereof will be described using the relationship with the casting method performed by the casting apparatus.

For casting, first, the movable mold 10 is moved to approach the fixed mold 12, and mold clamping is performed. As a result, the cavity forming portions 14a and 14b and the cavity forming portion form the cavity 16. At the same time, the overflow 34 and the cooling exhaust 30 are also formed.

Next, a melt L of a metal such as aluminum is supplied from the gate 20. The melt L is distributed through the runners 19 and introduced into the cavity 16 from each runner 19. Accordingly, the cavity 16 starts to be filled with the melt L. The melt L flows in the cavity 16 with the runner 19 as the upstream side and the end portion as the most downstream side.

When a predetermined amount of the melt L is introduced into the cavity 16, the melt L is discharged from the melt outlet 42. In other words, into the overflow 34. It is presumed that the overflowing melt L flows as follows.

As described above, the width of the melt outlet 42 becomes narrower toward the overflow 34 (see fig. 3). Therefore, the melt L spreads immediately after entering the melt reservoir 36 having a relatively large capacity (see fig. 2). That is, it is difficult to travel straight ahead, and convection is caused as indicated by the arrow. As a result, the melt L is temporarily accumulated in the melt accumulation portion 36. After that, while the melt reservoir 36 is filled with the melt L, a part of the melt L passes through the inclined surface provided at the melt outlet 42 and is introduced into the first melt filling portion 38 side connected to the melt reservoir 36 in a straight line.

In this way, the melt L flows into the melt reservoir 36 while spreading because the width of the melt outlet 42 is narrowed toward the overflow 34, and therefore the melt L is easily guided to the first melt-filling portion 38 while being temporarily stored in the melt reservoir 36. Further, since the gradient is provided at the melt outlet 42, the cross-sectional area of the melt outlet 42 can be ensured to be constant, and the exhaust velocity can be made constant.

A first bushing 44 is received in the first melt filling portion 38. Accordingly, the melt L enters the hollow interior of the first bushing 44 and is blocked by the tip of the first ejector pin 46.

In the case where the amount of the melt L overflowing is larger than the volumes of the melt reservoir 36 and the first melt filling portion 38, the melt L filling the first melt filling portion 38 is pushed out or directed toward the joining surface side by the excessive amount of the melt L. The extruded melt L or the melt L flowing directly toward the joining surface side is guided into the second melt filling portion 40 via the bent portion 48. In this process, the direction of travel of the melt L changes by approximately 90 ° when moving from the melt reservoir 36 to the bend 48 and when moving from the bend 48 to the second melt-filling portion 40.

As the melt passes through the bent portion 48, the flow velocity of the melt L decreases. Therefore, it is easy to prevent the melt L from leaking, so-called flash. In this case, the melt L is less likely to flow from the overflow 34 to the communication path 56. In other words, the melt L is easily filled in the second melt filling portion 40.

A second bushing 52 is received in the second melt filling section 40. Accordingly, the melt L enters the hollow interior of the second bushing 52 and is blocked by the tip of the second ejector pin 54.

The melt reservoir 36 is located adjacent to the melt outlet 42, and the first and second melt fill sections 38, 40 are located adjacent to the melt retention section. Accordingly, the melt L in the vicinity of the melt outlet 42 is heated by the melt L in the melt reservoir 36, the first melt fill portion 38, and the second melt fill portion 40. Therefore, since the temperature of the melt L can be prevented from rapidly decreasing in the vicinity of the melt outlet 42, the riser effect can be maintained.

If the melt L overflows further, the melt L enters the communicating path 56. In some cases, the exhaust gas reaches the cooling exhaust unit 30.

As described above, in the present embodiment, the melt L is temporarily accumulated in the melt accumulation portion 36. After that, since the positions of the first melt filling part 38 and the second melt filling part 40 are made asymmetric, most of the melt L flows into the first melt filling part 38 first and then flows into the second melt filling part 40. That is, the melt L flows from the first melt filling portion 38 to the second melt filling portion 40 in sequence.

The overflowed melt L is thus stored in the melt reservoir 36, and the flow rate is reduced. Also, since the flow is performed through the first melt-filling part 38 and the second melt-filling part 40 in this order thereafter, it stays in the overflow part 34 for a long time. Therefore, the temperature of the melt L decreases relatively quickly.

Further, a large amount of the melt L can be stored by the melt reservoir 36, the first melt filling part 38, and the second melt filling part 40. Therefore, the flow velocity of the melt L entering the communication path 56, and sometimes the melt L entering the cooling gas discharge portion 30, is sufficiently reduced, and the temperature is sufficiently lowered, and the amount thereof is small. Therefore, the melt L reaching the communication path 56 and the cooling and gas-discharging unit 30 is cooled and solidified in a short time.

Therefore, it is not particularly necessary to form the cooling exhaust unit 30 to have a large capacity. Accordingly, the cooling exhaust unit 30 can be downsized. Therefore, the fixed die 12 and the movable die 10 as the dies can be reduced in size and weight, and therefore the cost required for the dies can be reduced.

As shown in fig. 4, the melt L filled in the cavity 16 is cooled and solidified, and thereby two side cases 18a and 18b can be obtained as castings. The side shells 18a, 18b are connected via a technical section 22. As shown in fig. 4 and 5, the side cases 18a and 18b are provided with overflow portion corresponding portions 60 formed by cooling and solidifying the melt L retained in the overflow portions 34. The overflow portion corresponding portion 60 includes: a melt reservoir counterpart 62, a first melt fill counterpart 64, a second melt fill counterpart 66, and a communication path counterpart 68 (see fig. 5).

After the movable die 10 is moved in a direction away from the fixed die 12 to open the die, the casting is pressed by the first ejector pin 46, the second ejector pin 54, and the like to be released from the die. By cutting the finished part 22 and the relief part corresponding part 60, the side shells 18a and 18b having a shape similar to that of the final product can be obtained.

The present invention is not particularly limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, the first melt filling part 38 and the second melt filling part 40 may be arranged symmetrically. In addition, it is also possible to provide the first melt filling portion 38 on the fixed mold 12 and the second melt filling portion 40 on the movable mold 10, in contrast to the above.

Further, the passage path of the communication path 56 may be set smaller than the passage paths of the first melt-filling part 38 and the second melt-filling part 40. Accordingly, the melt L flows into the communication path 56 side after being filled into the first melt filling part 38 and the second melt filling part 40. That is, the inflow sequence of the melt L becomes more reliable.

[ description of reference ]

10: a movable mould; 12: a fixed mold; 14a, 14 b: a cavity forming part; 16: a cavity; 18a, 18 b: a lateral housing; 30: a cooling exhaust part; 34: an overflow section; 36: a melt reservoir; 38: a first melt filling section; 40: a second melt filling section; 42: a melt outlet; 56: a communication path; 60: an overflow portion corresponding portion; 62: a melt accumulation section corresponding section; 64: a first melt filling part corresponding part; 66: a second melt filling part corresponding part; 68: a communication path corresponding portion; l: and (4) melting the melt.

Claims (7)

1. A casting apparatus having a fixed die (12) to be positioned and fixed and a movable die (10) to be moved in a direction approaching or separating from the fixed die (12), a cavity (16) being formed by the fixed die (12) and the movable die (10) at the time of mold clamping,

a gas discharge portion (30), an overflow portion (34) and a melt outlet (42) are formed, wherein,

one end of the gas discharge portion (30) communicates with the cavity (16), and the other end is open to the atmosphere;

the overflow part (34) is arranged between the gas discharge part (30) and the cavity (16) and is used for the melt overflowing from the cavity (16) to enter;

the melt outlet (42) being directed from the mold cavity (16) towards the overflow (34),

the overflow part (34) has melt filling parts (38, 40) extending in a direction orthogonal to the joint surface of the fixed die (12) and the movable die (10),

the melt outlet (42) is formed at the engagement face,

a communication path (56) that communicates the overflow section (34) with the gas discharge section (30) is formed at a position offset in a direction parallel to the joint surface with respect to the melt outlet (42),

the gas discharge portion (30) is formed along the joint surface.

2. Casting device according to claim 1,

the melt filling parts (38, 40) are provided on the fixed die (12) and the movable die (10), respectively, and the melt filling part (40) on the fixed die (12) side and the melt filling part (38) on the movable die (10) side are positioned asymmetrically.

3. Casting device according to claim 1 or 2,

the overflow part (34) has a melt reservoir (36), and the melt reservoir (36) is provided upstream of the melt filling parts (38, 40) and temporarily stores the melt overflowing from the cavity (16).

4. Casting device according to claim 3,

the melt outlet (42) is set to have a width that narrows from the cavity (16) toward the overflow (34).

5. Casting device according to claim 4,

a gradient is provided at the melt outlet (42) in such a way that the gradient develops from the mold cavity (16) towards the overflow (34).

6. A casting apparatus having a fixed die (12) to be positioned and fixed and a movable die (10) to be moved in a direction approaching or separating from the fixed die (12), a cavity (16) being formed by the fixed die (12) and the movable die (10) at the time of mold clamping,

a gas discharge portion (30), an overflow portion (34) and a melt outlet (42) are formed, wherein,

one end of the gas discharge portion (30) communicates with the cavity (16), and the other end is open to the atmosphere;

the overflow part (34) is arranged between the gas discharge part (30) and the cavity (16) and is used for the melt overflowing from the cavity (16) to enter;

the melt outlet (42) being directed from the mold cavity (16) towards the overflow (34),

the overflow part (34) has two melt-filling parts (38, 40) extending in a direction orthogonal to the joint surfaces of the fixed die (12) and the movable die (10), respectively,

one of the two melt-filling parts (38, 40) is provided with a melt-filling part (38) on the upstream side, the other melt-filling part (40) is provided with a melt-filling part on the downstream side,

and the two melt-filled portions (38, 40) are arranged asymmetrically such that the melt flows into the melt-filled portion (38) of the one side on the upstream side and then flows into the melt-filled portion (40) of the other side on the downstream side.

7. Casting device according to claim 6,

the overflow part (34) has a melt reservoir (36), and the melt reservoir (36) is provided upstream of the melt filling parts (38, 40) and temporarily stores the melt overflowing from the cavity (16).

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