JPH09300057A - Mold degassing device and casting method using mold degassing device - Google Patents

Abstract

(57) [Abstract] (Correction) [Problem] To make a cast product with no gas entrapment and without shrinkage cavities, and when the molten metal jumps into the passage, the device can be easily removed and cleaned. SOLUTION: A molten metal pool 15 is provided on a mold dividing surface 8 part in the middle of a gas vent passage 14 communicating from a mold cavity 11 to the outside of the mold.
A hole having a diameter smaller than the diameter of the basin 15 and leading to the outside at a part of the rear is provided in the center of the basin 15 in parallel with the mold clamping direction so that it can be attached to and removed from the mold body, A pin 17 having a gas vent groove extending in the axial direction is slidably provided in a part of the outer peripheral surface after the tip portion 17a in the hole, and the pin 17 and the gas reservoir 15 are provided at the forward and backward limit positions. Providing passages that can cut off the cutouts between the inner peripheral surface of the tip portion 17a of the hole and the outer peripheral surface of the tip portion 17a of the pin 17, a spring for pulling back the pin 17 is provided between the outer peripheral portion of the pin 17 and the block. A mold degassing device installed between the two parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold degassing device and a casting method using the mold degassing device. When the mold cavity is filled with molten metal for casting, By extracting a large amount of gas from the mold cavity, filling the mold with molten metal, and then pressurizing the molten metal with a pin, it is possible to create a cast product without gas entrapment and without shrinkage cavities. In addition, when the molten metal jumps into the passage, the device can be easily removed and cleaned.

[0002]

2. Description of the Related Art Conventionally, as for a method of extracting gas from a mold, for example, Japanese Patent Publication No. 58-46387,
Although those disclosed in Japanese Examined Patent Publication No. 59-309 and Japanese Examined Patent Publication No. 2-38061 have been put into practical use, the molten metal that jumps in together with the gas may block the passage of the gas. In addition, to prevent shrinkage cavities, a pressure pin is placed near the location where the shrinkage cavities occur, and pressure is applied in accordance with the timing of solidification contraction of the molten metal. In many cases, the pressure pins cannot be arranged. Especially for castings that require a thick wall around the product, it is often difficult to arrange the pressure pins. It was difficult to clean when I entered.

[0003]

When the gas is taken out, the molten metal that jumps in together with the gas is prevented from blocking the gas passage, and the molten metal is pressurized with a pin by utilizing a pool provided in the middle of the gas passage. ， Prevent the occurrence of shrinkage cavities around the product, and if the molten metal enters the gas passage, remove only that block for easy cleaning.

[0004]

[Means for Solving the Problems] In order to solve these problems, a basin is provided on the mold dividing surface part in the middle of a gas vent passage leading from the dies cavity to the outside of the dies, A block with a small diameter that opens to the outside at a part of the rear is provided parallel to the mold clamping direction at the center of the basin and is attached to the mold body so that it can be removed. A pin having a gas vent groove extending in the axial direction is slidably provided in the hole, and a passage is formed in the tip end portion of the hole to allow communication between the hot water reservoir and the gas vent groove at the forward and backward limit positions of the pin. A die degassing device was provided between the peripheral surface and the outer peripheral surface of the tip of the pin, and a spring for pulling back the pin was provided between the outer peripheral portion of the pin and a part of the block. At this time, it is effective to make the shape of the hot water pool spiral.
It has been put to practical use in No. 82384. Also, an actuator such as a pin moving cylinder is provided at the rear of the pin that is slidably provided in the hole in the block.

When casting, the die degassing device is used to advance the pin so that the molten metal and the degassing groove communicate with each other to discharge the gas in the die cavity to the outside of the die. During the filling of the molten metal, the molten metal is cooled and solidified in the narrow gap between the inner surface of the pool and the tip of the pin to prevent the molten metal from entering the degassing groove, and the pin is retracted just before the completion of the molten metal filling. The pool and the degassing groove were blocked, and when the melt was solidified and contracted after the completion of the melt filling, the pin was advanced again to exert a pushing force on the melt in the pool.

When the filling of the molten metal into the mold cavity is started with the pin having the gas vent groove facing the center of the molten metal pool being advanced, the gas extruded by the molten metal filled is in the groove of the pin. Is discharged through the gap. Then, when the gas expanded by the heat of the molten metal entrains a part of the molten metal and jumps into the pool, the molten metal flows along the wall surface of the pool due to its inertia, and if the diameter of the small diameter of the center of the pool is small. Even if it enters the gas vent passage, it immediately cools and solidifies so that it does not go deep.

When the molten metal fills most of the mold cavity, when the grooved pin is retracted, the gas passage is closed, but the amount of remaining gas is small so that it is contained in the pool and the product part It is possible to obtain a cast product without gas entrapment. When a load is applied to the pin to pressurize it in accordance with the state of solidification of the molten metal in the pool, pressure is applied to the semi-solidified melt in the pool. The product is sent back to the peripheral part of the product to supplement the volume of coagulation and shrinkage of the product and prevent shrinkage. If the molten metal enters the passage, remove the block containing the pin and the spring for pulling back the pin from the mold body, disassemble and clean, and reassemble and install.

[0008]

1 to 5 show an embodiment of an apparatus for carrying out the method of the present invention. FIG. 1 is a longitudinal sectional view and FIG. 2 is a sectional view taken along line AA of FIG. 3 and 5 are detailed views of the degassing block portion. Figures 1 and 2 show the structure near the die of the horizontal die clamping horizontal casting die casting machine.
1 is a fixed plate, 2 is a movable plate, 3 is a fixed mold, 4 is a movable mold, 5 is a casting sleeve, 6 is a plunger, 7 is a plunger tip, 8 is a mold dividing surface, and 9 is a mold dividing surface. 8 is a runner part through which the molten metal 10 flows, 11 is a cavity provided on the mold dividing surface 8, 12 is a seal made of an O-ring or the like attached near the outer periphery of the mold dividing surface 8 of the fixed mold 3, 13 Is a column.

Cavity 11 of the mold shown in FIGS.
Although one example is shown, a gas vent passage 14 that finally communicates with the outside of the mold is provided above the part of the cavity 11 in the part 8 of the mold dividing surface. A hot water reservoir 15 was provided on the upper part of the mold dividing surface 8 partly in the middle of the gas vent passage 14.

A hole 16 having a diameter smaller than the diameter of the inscribed circle of the basin 15 and having a perfect circular cross section that communicates with the outside of the mold at a part of the rear is provided in the center of the basin 15 parallel to the mold clamping direction. Block 2
3 was detachably attached to the fixed mold 3 using the block pressing plate 24 and the bolt 25. A cylindrical pin 17 is provided in the hole 16 so as to be slidable in the axial direction so that the tip end 17a of the pin 17 can be inserted into and taken out from the hole 16, and a spring is held in a block 23 for degassing. Board 23a
The compression spring 21 is inserted between the pin 17 and the flange portion 17b provided on the outer peripheral portion of the pin 17 at the rear side, and the pin 17 is normally pulled back.

A plurality of degassing grooves 19 extending in the axial direction or integrally formed on the entire circumferential surface are provided in a part of the outer peripheral surface at the rear of the tip portion 17a of the pin 17 in the axial direction. . Reference numeral 20 is a gas passage provided in the fixed mold 3 so that a part of the gas vent groove 19 is communicated with the outside of the mold, and 22 is a seal such as an O-ring. Reference numeral 26 is a hydraulic cylinder attached to the back surface of the fixed mold 3. The piston rod 27 of the hydraulic cylinder 26 is completely concentric with the pin 17, or one hydraulic cylinder operates a plurality of pins. At this time, the pressure rod of the connecting member (not shown) and the pin 17 are concentrically attached. The pin 17 is mounted in the block 23 via the compression spring 21.

The hot water reservoir 15 and the gas vent groove 19 are communicated with each other at the forward limit position of the pin 17, and the passage 18 that can shut off the hot water reservoir 15 and the gas vent groove 19 at the backward limit position of the pin 17 is provided on the hot water reservoir 15. Inner peripheral surface of the tip of the hole 16 and the tip 17a of the pin 17
It is provided between the outer peripheral surface. In this embodiment, as shown in FIG. 3, the passage 18 is formed in the hole 16 at the inner peripheral surface of the tip of the hole 16.
For example, a hole larger than the inner diameter of 6 by 1 to 3 mm was processed and formed.

Next, the operation of casting using this apparatus will be described with reference to FIGS. 1 and 6 to 8. FIG. 6A shows a state in which the degassing block 23 is attached to the fixed mold 3. The molten metal 10 poured into the casting sleeve 5 of the casting machine is pushed into the cavity 11 by the advance of the plunger tip 7 at the tip of the plunger 6.

At this time, the tip portion 17a of the pin 17 is projected into the pool 15 by the action of the hydraulic cylinder 26 as shown in FIG. 6 (b), and the gas in the cavity 11 is indicated by an arrow. As shown, degassing passage, pool 1
5, it passes through the passage 18, the gas vent groove 19, and the gas passage 20, and is discharged to the outside. At this time, if the gas passage 20 is connected to a vacuum device (not shown), the gas in the cavity 11 can be sufficiently discharged. Further, in that case, it is necessary to attach the seal 12 to the mold dividing surface 8 in order to prevent air from entering the cavity 11 from the mold dividing surface 8, but the gas outlet is provided in the mold dividing surface 8. Since there is no seal, it can be completely sealed.

When the molten metal 10 is filled in the cavity 11, due to the rapid expansion of the gas caught in the molten metal 10,
The hot water may jump into the hot water pool 15, but it collides with the outer wall surface of the hot water pool 15 due to inertia, and the pin 1 near the center
It rarely jumps into the depth of the gas passage 18 which is a small gap on the outer periphery of the gas passage 7 and closes it. However, if the hot water jumps into the degassing groove 19, it is necessary to remove it. Therefore, the block 23 can be removed from the fixed mold 3 for cleaning.

Immediately before the molten metal 10 fills the cavity 11, as is well known in the art, for example, when a preset time elapses from the start of pouring the molten metal 10 or the flow of the molten metal 10 is stopped. When the piston rod 27 of the hydraulic cylinder 26 is pulled down, the pin 17 is pulled down by the operation of the spring 21, and a small amount of the gas remaining in the cavity 11 is compressed and contained in the basin 15. The molten metal 10 that has entered the pool 15 is cooled and solidified in the passage 18 which is a small gap around the pin 17 and does not enter the gas vent groove 19 or the gas passage 20. This state
It is shown in FIG.

When the filling is completed and the molten metal 10 starts to solidify, the pin 17 is pushed out by the force of the hydraulic cylinder 26, and
A feeder force is applied to the molten metal 10 in the container 5. This state is shown in FIG. As indicated by the white arrow, when the pin 17 presses the molten metal 10 in the basin 15 with a high surface pressure, the metal is semi-solidified or plastically fluidized to move from the basin 15 to the cavity 11
It flows backward into the cavity 11 and replenishes and compresses the metal in the gap due to the solidification contraction generated in the cavity 11 to prevent the shrinkage cavity. This method is particularly effective for preventing shrinkage cavities in a cast product having a thick portion around the cavity 11.

When the molten metal 10 is completely cooled and the movable mold 4 is opened, the pin 17 is further advanced to project the product 28. This state is shown in FIG. After the product 28 is taken out, as shown by an arrow in FIG. 8B, compressed air is sent backward from the gas passage 20 to clean the passage 18 which is the gap between the pins 17 and the spray device 29. The mold release agent 30 is sprayed on the tip portion 17a of the pin 17 or the like to prepare for the next casting.

When the piston rod 27 of the pressure cylinder 26 retracts, the pin 17 retracts due to the force of the compression spring 21. Since the pin 17, the compression spring 21 and the like are gathered in a block 23 for degassing different from the fixed mold 3 and attached to the fixed mold 3 with a block retainer 24 and a bolt 25, the gas vent groove 19 is clogged. When you do, you can remove and clean it.

[0020]

As described above, according to the present invention, a hot water pool is provided on the mold dividing surface part in the middle of the gas vent passage leading from the mold cavity to the outside of the mold, and the diameter is smaller than the diameter of the hot water pool. A block with a hole that communicates with the outside at the center of the basin and parallel to the mold clamping direction is attached to the mold body so that it can be removed and extended in the axial direction on a part of the outer peripheral surface after the tip. A pin having a gas vent groove is slidably provided in the hole, and a passage is formed at the forward end and the rear end position of the pin, which can cut off the hot water reservoir and the gas vent groove, respectively, from the inner peripheral surface of the tip of the hole and the pin. Since a spring for pulling back the pin is provided between the outer peripheral surface of the tip and a part of the inside of the block, the gas in the mold cavity can be sufficiently discharged. ， It is possible to prevent the molten metal from jumping out of the pool. Further, by stably discharging the gas in the mold cavity during casting, gas entrapment is eliminated, which enables high-speed casting for thin wall casting with fast cooling.

Further, when the die degassing device is used to advance the pin during the filling of the molten metal so that the hot water reservoir and the degassing groove are communicated with each other to discharge the gas in the die cavity to the outside of the die, The molten metal is prevented from entering the degassing groove by cooling and solidifying in a small gap in the pool, and the pin is retracted just before the completion of the molten metal filling to shut off the molten metal pool and the degassing groove. When the solidification shrinks, the pin is moved forward again to apply the pushing force to the molten metal in the pool for casting, so that the pressurizing effect of the pin prevents the occurrence of shrinkage cavities in the thick part around the casting. As a result, it is possible to produce a dense, high-strength, high-quality cast product.

If the molten metal jumps into the degassing groove and causes malfunction of the device, the pressurizing pin and the piston rod of the pressurizing cylinder are not connected and the degassing block can be easily removed. Since this is done, the device can be easily cleaned.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a detailed view of a degassing block portion of the apparatus shown in FIG.

FIG. 4 is a plan view of FIG. 3;

5 is a view taken along the line BB of FIG.

6 is a vertical cross-sectional view showing the operation sequence in the device shown in FIG.

FIG. 7 is a vertical cross-sectional view showing the sequence of actions subsequent to FIG.

8 is a vertical cross-sectional view showing the sequence of actions subsequent to FIG.

[Explanation of symbols]

 1 Fixed plate 2 Movable plate 3 Fixed mold 4 Movable mold 5 Casting sleeve 6 Plunger 7 Plunger tip 8 Mold dividing surface 9 Runner part 10 Molten metal 11 Cavity 12, 22 Seal 14 Gas vent passage 15 Hot water reservoir 16 Hole 17 Pin 17a Tip portion 18 Passage 19 Gas vent groove 20 Gas passage 21 Compression spring 23 Block for venting gas 24 Block holding plate 25 Bolt 26 Hydraulic cylinder (actuator) 27 Piston rod 28 Product 29 Sprayer 30 Release agent

Claims (3)

[Claims] 1. A hot water reservoir is provided on a mold dividing surface part in the middle of a gas vent passage leading from the mold cavity to the outside of the mold, and a hole having a diameter smaller than that of the hot water reservoir and communicating with the outside at a part of the rear side is hot water. A block provided parallel to the mold clamping direction at the center of the reservoir is attached to the mold body so that it can be removed, and a pin having a gas vent groove extending in the axial direction is attached to a part of the outer peripheral surface after the tip. A passage slidably provided in the hole is provided between the inner peripheral surface of the tip of the hole and the outer peripheral surface of the pin at the forward limit and the backward limit position of the pin for communicating and blocking the hot water tank and the gas vent groove. A degassing device for molds, in which a spring for pulling back the pin is provided between the outer periphery of the pin and a part of the block. 2. An actuator for a pin is provided at a rear portion of a pin slidably provided in a hole in a block.
The degassing device for the die described. 3. A hot water reservoir is provided on the mold dividing surface part in the middle of a gas vent passage leading from the mold cavity to the outside of the mold, and a hole having a diameter smaller than the diameter of the hot water reservoir and communicating with the outside at a part of the rear is heated. A block provided parallel to the mold clamping direction at the center of the reservoir is attached to the mold body so that it can be removed, and a pin having a gas vent groove extending in the axial direction is attached to a part of the outer peripheral surface after the tip. A passage slidably provided in the hole is provided between the inner peripheral surface of the tip of the hole and the outer peripheral surface of the pin at the forward limit and the backward limit position of the pin for communicating and blocking the hot water tank and the gas vent groove. Using a die degassing device, in which a spring for pulling back the pin is provided between the outer periphery of the pin and a part of the block, the pin is moved forward to communicate the hot water reservoir with the degassing groove. While filling the molten metal, which is discharging the gas in the cavity to the outside of the mold,
The molten metal is cooled and solidified in a narrow gap between the inner surface of the pool and the tip of the pin to prevent the molten metal from trying to enter the degassing groove. A casting method using a degassing device for a die, in which a groove is blocked and a pin is advanced again when the molten metal is solidified and contracted after the molten metal is filled so that a pushing force is applied to the molten metal in the pool.