JP2000312959A - Casting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fully perform a gas releasing function, a function for releasing a mold of a molding article, and a function for preventing clogging of a passage for gas releasing and the like, even when a thin molding article is cast. SOLUTION: This device is equipped with an upper movable die 7 and a lower fixed die 8 for forming a cavity 9, ejector pins 12 protruding to the cavity side in a rising process of the movable die 7, and gas releasing pins 13 which have grooves 16 for forming a gas releasing passage on a periphery and protrude after protrusion of the ejector pins 12. In this case, when a thin molding article is cast, each of the pins 12 and 13 is arranged at an optimum portion, so as to secure a function for releasing gas, a function for releasing a mold of the molding article, and a function for preventing clogging of the gas releasing passage and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting apparatus,
In particular, the present invention relates to a casting apparatus suitable for producing a thin molded product.

[0002]

2. Description of the Related Art Casting articles such as intake manifolds and collector manifolds of automobile engines are made of a thin material such as an aluminum alloy in order to reduce the weight. When casting such a thin molded product, the most important issue is to ensure the ability to flow, and a solution to this problem is to release the gas inside the cavity to the outside of the mold during casting. Have been.

[0003] In a conventional casting apparatus, the structure for releasing gas in the cavity has a structure in which an air vent having a slit is provided on the inner surface of a mold, and an ejector pin for releasing a molded product. Some provided a groove for forming a path.

[0004]

However, in the casting apparatus having the above-described conventional gas release structure, which uses an air vent having a slit, the molten metal easily enters the slit and the slit is formed by solidification of the molten metal. There was a problem such as being blocked. On the other hand, the one using an ejector pin having a groove has a very small amount of molten metal, has a function of releasing gas, a function of releasing a molded product, and a gas generated by projecting toward a cavity at the time of release. It also has functions to prevent clogging of the discharge channel. However, an ejector pin having a groove, particularly when used for casting a thin-walled molded product, is likely to be cracked in the molded product due to local pressing, even if it is desired to dispose it on a portion having poor runnability. It can be placed only on thick parts such as bosses and fried parts, and in the end, there is a problem that the function of gas release cannot be sufficiently exhibited in the casting apparatus for thin molded products. The task was to solve the problems.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a function of releasing gas, a function of releasing a molded product, and a function of releasing a molded product even when casting a thin-walled molded product. It is an object of the present invention to provide a casting apparatus capable of sufficiently exhibiting a function of preventing clogging of a gas discharge channel.

[0006]

According to a first aspect of the present invention, there is provided a casting apparatus, wherein an upper movable mold and a lower fixed mold forming a cavity which is a casting space are movable together with the movable mold in a rising process. An ejector pin protruding from the mold toward the cavity, and a gas discharge pin protruding from the movable mold toward the cavity after projecting the ejector pin and having a groove for forming a gas discharge channel between the movable die and the movable die on the outer periphery. A fixed platen disposed above the movable die, a first plate holding the ejector pins in the movable die, a second plate holding the gas discharge pins in the movable die, First and second pushing members provided on the first and second plates and abutting on the fixed platen during the ascending process of the movable mold, and a position where the lower end of each pin enters the movable mold. An elastic body for elastically holding each plate is provided, and a vertical interval between the fixed platen and the second extruding member is made larger than an vertical interval between the fixed platen and the first extruding member. The second plate is disposed above the one plate, and the two plates are configured to abut on each other in the mold closed state. According to a fourth aspect, the gas discharge pins of the second plate slidably penetrate the first plate. In the fifth aspect, the first
The first pushing member of the plate is slidably penetrating the second plate, and the above-described structure is a means for solving the conventional problem.

[0007]

In the casting apparatus according to the first aspect of the present invention, since a gas discharging pin having a groove is provided separately from the ejector pin, for example, when casting a thin-walled molded product, a boss or a lift is required. The ejector pins can be arranged on the thicker portion of the device, and the gas discharge pins can be arranged on the portion with poor runoff. Thereby, at the time of casting, the gas inside the cavity is released to the outside from the gas release channel formed by the groove of the gas release pin, so that the runoff property is improved. After the casting, the movable die protrudes during the ascending process. The mold release of the molded article is performed favorably by the ejector pin, and furthermore, by projecting the gas discharge pin after the ejector pin is projected, the gas discharge pin is prevented from contacting the molded article,
Prevents clogging of the gas discharge channel.

[0008] In the casting apparatus according to claim 2 of the present invention,
As the movable mold is raised, the vertical interval between the fixed platen and the second extrusion member is made larger than the vertical interval between the fixed platen and the first extrusion member. Abuts against the fixed platen to prevent the first plate from rising, and then, as the movable die rises against the elastic body of the first plate, the ejector pins of the first plate protrude toward the cavity. . Thereafter, when the movable die further rises, the second pushing member comes into contact with the fixed platen to prevent the second plate from rising, and then the movable die rises against the elastic body of the second plate. With the second
The gas discharge pins of the plate protrude toward the cavity.
When the movable mold is lowered, the second plate returns to a position where the lower end of the gas discharge pin is immersed in the movable mold by the action of the elastic body of the second plate. By the action of the body, the first plate returns to the position where the lower end of the ejector pin is immersed in the movable mold.

[0009] In the casting apparatus according to claim 3 of the present invention,
In the mold closed state, the second plate abuts on the first plate in an overlapping manner, so that the lowering of the second plate is surely restricted by the first plate, and the gas discharge pins of the second plate move the lower end of the movable plate. It is surely regulated to the position immersed in.

[0010] In the casting apparatus according to claim 4 of the present invention,
Since the gas discharge pins of the second plate slidably penetrate the first plate, the second plate ascending and descending is guided by the first plate.

[0011] In the casting apparatus according to claim 5 of the present invention,
Since the first pushing member of the first plate slidably penetrates the second plate, the first plate moving up and down is the second plate.
Guided by the plate.

[0012]

According to the casting apparatus according to the first aspect of the present invention, even when casting a thin molded product, the ejector pins are arranged on a thick portion such as a boss or a fry,
The gas discharging pin can be freely arranged for the part with poor running ability, and during casting, the gas can be smoothly released by the gas discharging pin, thereby improving the running property. Thus, casting defects due to gas can be eliminated and a high quality molded product can be cast. Further, after casting, the molded product can be released from the molded product by the ejector pin, and the molded product is damaged by the gas releasing pin by projecting the gas releasing pin after the ejector pin is projected. Such a situation can be solved, and clogging of the gas discharge channel can be prevented.

According to the casting apparatus of the second aspect of the present invention, the same effect as that of the first aspect can be obtained.
The ejector pin and the gas discharge pin can be sequentially projected with the rise of the movable mold using only the driving means for moving the movable mold up and down, and the ejector pin and the gas discharge pin are moved to their original positions as the movable mold descends. Thus, the structure can be simplified, the weight can be reduced, and the equipment cost can be reduced.

According to the casting apparatus of claim 3 of the present invention, the same effect as in claim 2 can be obtained,
On the upper side of the first plate provided with the ejector pins to be projected first, the second plate provided with the gas discharge pins projected from the rear.
By arranging the plate, the height of the apparatus can be kept small.
The second plate and the gas releasing pin can be reliably positioned at the lower limit by the plate, and the risk of causing a casting defect such as unevenness in the molded product by the gas releasing pin can be surely eliminated.

According to the casting apparatus of claim 4 of the present invention, the same effect as in claim 3 can be obtained,
Since the gas discharge pins of the second plate are slidably penetrated through the first plate, the second plate ascending and descending is guided by the first plate without using another guide means. The operation of raising and lowering the gas discharge pin can be made smoother, and the structure can be further simplified and the weight can be reduced.

According to the casting apparatus of claim 5 of the present invention, the same effect as in claims 3 and 4 can be obtained, and the first pushing member of the first plate slides on the second plate. By freely penetrating, the first plate that moves up and down can be guided by the second plate without using another means, so that the operation of raising and lowering the first plate and the ejector pins can be more smoothly performed, and the structure can be improved. Can be further simplified and lightened.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a casting apparatus according to the present invention will be described below with reference to the drawings.

In the casting apparatus shown in FIG. 1A, a plurality of guide posts 2 are erected on a base 1, and a plate-shaped fixed platen 3 is horizontally held at the upper end of each guide post 2, and each A movable platen 4 in the form of a plate is provided on the guide post 2 so as to be movable up and down horizontally, and a fixed platen 3 is provided with a driving cylinder 5 for driving the movable platen 4 up and down.

In the casting apparatus, the upper movable die 7 is held by the die holder 6 provided on the lower surface of the movable platen 4, and the lower fixed die 8 is provided on the upper surface of the base 1 so as to face each other vertically. The movable mold 7 and the fixed mold 8 form a cavity 9 as a casting space. In this embodiment, a core 10 is set in the cavity 9 as shown by a dotted line in the case of casting a thin molded product.

The movable die 7 has a hollow portion 11, in which a first plate P1 holding a plurality of ejector pins 12 penetrating the movable die 7 downward, and a movable die 7 likewise. A plurality of gas discharge pins 13 penetrating downward
The second plate P2 that holds the is accommodated in a vertically movable manner. The first plate P1 has a return pin 15 that penetrates the movable mold 7 downward and abuts the shoulder 14 of the fixed mold 8.
Is provided.

The ejector pin 12 is disposed on a thick portion A such as a boss so that a local pressing does not cause a crack in the molded product when the molded product is thin. I have.

On the other hand, the gas discharge pins 13 are arranged in the cavity 9 at portions where the meltability becomes poor, in consideration of the shape of the molded product. This gas discharge pin 13
As shown in FIG. 1 (b), the outer periphery has a plurality of grooves 16 along the axial direction on the outer circumference, and the grooves 16 form a gas discharge channel with the movable mold 7. That is, the gas in the cavity 9 passes through the groove 16 of the gas discharge pin 13 as shown by the arrow in FIG.
And further discharged outside through a path (not shown).

The first and second plates P1 and P2 are
The first plate P1 is arranged vertically with the lower side facing down. Here, each gas discharge pin 13 held by the second plate P2 slidably penetrates the first plate P1.
Further, the first and second plates P1 and P2 are provided with first and second pushing members Q1 and Q2 which slidably penetrate the movable mold 7 and the movable platen 4 and protrude upward. . Here, the first pushing member Q1 provided on the first plate P1 slidably penetrates the second plate P2.

In this embodiment, each of the pushing members Q1, Q
2 has a circular rod shape, and flange portions F1 and F2 are provided at the respective upper end portions.
1, F2 and the movable platen 4, each plate P 1, P
Elastic bodies 17 and 18 for elastically holding 2 are interposed. The elastic members 17 and 18 of this embodiment are compression coil springs.

The pushing members Q1 and Q2 come into contact with the lower surface of the fixed platen 3 in the process of ascending the movable mold 7, and in the closed state shown in FIG.
The vertical interval D2 between the fixed platen 3 and the second extrusion member Q2 is larger than the vertical interval D1 between the first extrusion member Q1 and the first extrusion member Q1. Although FIG. 1A shows one extrusion member Q1 and Q2, it is more desirable to provide a plurality of extrusion members, for example, in a symmetrical arrangement.

In the casting apparatus having the above structure, in the closed state shown in FIG. 1, the lower end of the return pin 15 abuts on the shoulder 14 of the fixed die 8, and each ejector pin 12 and each gas discharge pin 13 The lower end of the pin is immersed in the movable mold 7, and more precisely, each pin 12, 13
And a predetermined distance is formed between the first plate P1 and the bottom surface of the hollow portion 11 of the movable mold 7, and a second plate is provided above the first plate P1. P2 will be in a state of polymerization contact. At this time, the first
The plate P1 prevents the lowering of the second plate P2 and positions the gas discharge pins 13 at the lowermost position. This ensures that the gas discharge pins 13 may give casting defects such as irregularities to the molded product. Preventing.

The casting apparatus fills the cavity 9 with molten metal from a gate (not shown) in the above-described state. At this time, in this casting apparatus, since the gas discharging pin 13 is disposed in a portion having poor running property, the gas discharging pin 1
As shown in FIG. 1B, the gas in the cavity 9 is released as shown in FIG. 1 (b) by the filling of the molten metal by the groove 16 of 3, so that the meltability is improved and casting defects due to the gas are eliminated.

Next, the casting apparatus, after the molten metal has solidified,
When the movable mold 7 is moved up together with the movable platen 4 by the driving cylinder 5, the molded article is attached to the movable mold 7. At this time, the plates P1 and P2 and the pins 12 and 13 are held by the elastic members 17 and 18, so that they rise together with the movable mold 7 without lowering.

In the ascending process of the movable die 7, as described above, the fixed platen 3 and the second pushing member Q1 are moved relative to the vertical distance D1 between the fixed platen 3 and the first pushing member Q1.
2, the first pushing member Q1 first contacts the fixed platen 3, as shown in FIG.
Thus, the first plate P1 is prevented from rising, and the ejector pins 12 of the first plate P1 are moved toward the cavity as the movable die 7 rises while compressing the elastic body 17 of the first plate P1. (Lower side) and the molded product M
Is extruded from the movable mold 7. At this time, since the ejector pins 12 are arranged with respect to the thick portion A shown in FIG. 1A, the molded product M whose main part is thin does not crack, and the molded product M Satisfactorily.

When the movable die 7 further rises, the second pushing member Q2 comes into contact with the fixed platen 3, as shown in FIG. As a result, the second plate P2 is prevented from rising, and as the movable mold 7 rises while compressing the elastic body 18 of the second plate P2, the gas discharge pins 13 of the second plate P2 move to the cavity side ( (To the lower side) to prevent clogging of the gas discharge path. As described above, since the gas discharge pin 13 is protruded after the ejector pin 12 is protruded, the molded product M is formed by the gas discharge pin 13.
There is no risk of damaging the machine.

When the movable mold 7 is lowered during the next casting, the second plate P2 and the gas discharge pins 13 return to their original positions by the action of the elastic body 18 following the reverse of the upward movement. Then, the first plate P1 and the ejector pins 12 return to their original positions by the action of the elastic body 17, and the return pin 15 contacts the shoulder 14 of the fixed mold 4 with the closing of the mold. Due to the overlapping of P1 and P2, the plates P1 and P2 and the pins 12 and 13 are accurately positioned at the casting start position.

As described above, in the casting apparatus of the above embodiment, when casting a thin-walled molded product M, the ejector pins 12 are disposed on the thick portion A, and the gas is discharged on the portion having poor running property. The discharge pins 13 can be freely arranged, whereby a high-quality molded article M free of casting defects can be obtained.

The above-described casting apparatus uses only one driving cylinder 5 for driving the movable mold 7 up and down, and causes the ejector pins 12 and the gas discharge pins 13 to sequentially project as the movable mold 7 rises. The pins 12, 13 can be automatically returned to their original positions as the movable mold 7 descends,
In addition, during the elevating operation, the gas discharge pins 13 of the second plate P2 slidably penetrate the first plate P1,
In addition, since the first pushing member Q1 of the first plate P1 slidably penetrates the second plate P2, the first and second plates P1 and P2 ascending and descending are guided by each other. In other words, a smooth lifting operation can be performed with a simple structure without using another guide means.

The detailed structure of the casting apparatus according to the present invention is not limited to the above embodiment. For example, the structure of the elastic body for elastically holding each plate is as follows.
An elastic body is arranged below the first and second plates, and the elasticity of the elastic body below the second plate is larger than the elasticity of the elastic body below the first plate. Then, it is sufficient to provide the pushing member only on the upper second plate, and the lower elastic body and the upper elastic body are sequentially placed by the contact between the pushing member and the fixed platen accompanying the rise of the movable die. It is possible to cause the ejector pin and the gas discharge pin to sequentially protrude by compression.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a casting apparatus according to the present invention.
It is sectional drawing (a) explaining the state of a mold closure, and sectional drawing (b) which shows the vicinity of the pin for gas release.

FIG. 2 is a cross-sectional view illustrating a state in which a movable die has risen from the state of FIG. 1 and a first pushing member has contacted a fixed platen.

FIG. 3 is a cross-sectional view illustrating a state where the movable die further rises from the state of FIG. 2 and a second pushing member abuts on a fixed platen.

[Explanation of symbols]

 Reference Signs List 3 fixed platen 7 movable die 8 fixed die 9 cavity 12 ejector pin 13 gas discharge pin 16 groove 17 18 elastic body P1 first plate P2 second plate Q1 first extrusion member Q2 second extrusion member

Claims (5)

[Claims] 1. An upper movable mold and a lower fixed mold forming a cavity which is a casting space, an ejector pin projecting from the movable mold to the cavity side in a process of ascending the movable mold, and a movable mold on the outer periphery. And a gas discharge pin which protrudes from the movable mold toward the cavity after the ejector pin protrudes. 2. A fixed platen disposed above a movable die, a first plate holding an ejector pin in the movable die, and a second plate holding a gas discharge pin in the movable die.
Plates, first and second push-out members provided on the first and second plates and abutting on the fixed platen in the process of moving the movable die, 2. The apparatus according to claim 1, further comprising an elastic body for elastically holding the plate, wherein a vertical distance between the fixed platen and the second extrusion member is made larger than a vertical distance between the fixed platen and the first extrusion member. Casting equipment. 3. The casting apparatus according to claim 2, wherein a second plate is disposed above the first plate, and the two plates abut against each other in a mold closed state. 4. The casting apparatus according to claim 3, wherein the gas discharge pins of the second plate slidably penetrate the first plate. 5. The first pushing member of the first plate is a second pushing member.
The casting apparatus according to claim 3, wherein the plate is slidably penetrated through the plate.