JP2003326350A - Method and device for pulling out pin for hole as-cast in metallic mold for casting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent excess loading and development of such trouble as galling, etc., on a product when a pin for hole as-cast is pulled out after casting by using the plurality of pins for holes as-cast. <P>SOLUTION: On holding parts 17a-17d of a sliding plate 16 for holding the plurality of pins 8a-8d for holes as-cast, gap difference parts d of level for having the time difference when the pins are started to pull out, are arranged. Then, after casting by lowering the sliding plate 16 and simultaneously facing the pins 8a-8d for holes as-cast into a cavity C, when the pins 8a-8d for hole as-cast are pulled out by raising the sliding plate 16, the pins 8a, 8c, 8b, 8d for holes as-cast are made to pull out with the time difference in the order of smaller gap among the different parts d of level. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing technique for drawing a casting pin after casting a cylinder head having a casting hole for mounting a plug, for example.

[0002]

2. Description of the Related Art Conventionally, for example, when casting a cylinder head of a vehicle engine, a technique has been known in which a plug mounting hole is formed by a cast pin that can be moved back and forth toward the inside of a cavity. In the case of, for example, as shown in FIG. 5, after inserting the lower end portions of the plurality of casting pins 51 held by the sliding plate 55 into the cavity (not shown) to cast the cylinder head and solidify the molten metal, By operating the cylinder unit 52 to rotate the shaft fixed to the pinion gear 53 and sliding the sliding plate 55 having the rack gear portion 55g upward, the casting pins 51 can be simultaneously pulled out. There is.

[0003]

However, in the conventional case, since the structure is such that a plurality of casting pins 51 are simultaneously drawn, the drawing resistance of each casting pin 51 is applied at the same time, so that the shaft Etc. will be overloaded, and in some cases the shaft etc. may break,
There were defects such as galling, warpage and cracks in the product.

Therefore, according to the present invention, after casting using a plurality of casting pins, an excessive load is not applied to the shaft or the like when the casting pins are pulled out, and defects such as galling occur in the product. The purpose is not to.

[0005]

In order to achieve the above-mentioned object, the present invention is a drawing method for drawing a casting pin after casting a product having a plurality of casting holes with a plurality of casting pins, There is a time lag between the drawing start times of the plurality of casting pins, and when the drawing pin that first started drawing has completed drawing, the drawing of the drawing pin that started drawing last is completed. I was trying to get out of the product.

By thus providing a time difference between the pulling-out start timings of the plurality of casting pins, it is possible to prevent the load due to the pulling resistance from being dispersed and to prevent an excessive load from being applied to the shaft or the like. In addition, by making sure that the drawing pin that started drawing last is completed when the drawing pin that started drawing first completes drawing,
It is possible to prevent a decrease in work efficiency without increasing the conventional cycle time required for drawing.

Further, according to the present invention, in a pulling device for pulling out a plurality of casting pins which can be inserted into a cavity of a mold, sliding having a plurality of holding portions for holding the plurality of casting pins. A plate and a sliding mechanism for moving the sliding plate by a stroke are provided so that each casting pin can be pulled out by moving the sliding plate in a stroke in a predetermined direction. In the holding part, a clearance step portion is formed so that there is a time difference in the drawing start timing of each casting pin.

As described above, it is preferable that the holding portion of the sliding plate is provided with the clearance step portion so that the pulling start timing of each casting pin has a time difference by one stroke movement of the sliding plate. .

Further, in the present invention, as the sliding mechanism, a cylinder unit attached to the die side, a shaft rotatable by the operation of the cylinder unit, and the rotation of the shaft are made to slide on the sliding plate. A pinion rack mechanism for conversion is provided.

If the structure is such that the shaft is rotated by the cylinder unit and the casting pin is pulled out, the existing equipment can be utilized to the maximum extent, and the construction can be made more inexpensively and easily. .

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a schematic view of a casting mold to which a casting pin drawing apparatus according to the present invention is applied,
2 is a principal view of the sliding plate and the casting pin as seen from the front, FIG. 3 is an explanatory diagram of the drawing device, and FIG. 4 is an explanatory diagram of a clearance step portion of the sliding plate.

The drawing method and drawing device for the casting die of the casting die according to the present invention are, for example, when casting a cylinder head, after forming a plug mounting hole by using a plurality of casting pins, To avoid excessive load on the shaft when pulling out the product, and to prevent defects such as galling on the product, it is possible to take full advantage of the existing equipment configuration and respond with simple design changes. Has been done.

As shown in FIG. 1, an example of the die-casting die 1 for casting the cylinder head includes a lower die 2, storage cores 3 and 4 for intake and exhaust ports, and left and right sliding dies 5, 6 and
After the upper mold 7 is clamped to form a cylinder head molding cavity C of a four-cylinder engine, four casting pins 8a to 8d for molding a plug mounting hole are simultaneously inserted into the cavity C to form a lower mold. 2 When the molten aluminum is poured from the lower pouring port 9 and the solidification is completed, the casting pins 8a to 8d are pulled out and the mold is opened to take out the product. And
The four casting pins 8a to 8d are pulled out by a pulling device 10 described below with a time difference.

At this time, the cast pin 8a-
As shown in FIG. 2, 8d is arranged in a straight line, and a water cooling hose and an air cooling hose are connected to the two casting pins 8a and 8c, and the remaining two casting pins 8b and 8d are connected to each other. ,
Air cooling hose connected. And in the casting pins 8a and 8c in which the water cooling hose and the air cooling hose are connected, cooling water and air are circulated in the pins to cool the pins, and in the casting pins 8b and 8d to which the air cooling hose is connected, The pins are cooled by circulating air inside.

For this reason, the molten metal around the casting pins 8a and 8c, which is cooled by using cooling water, solidifies quickly and must be drawn earlier than the other casting pins 8b and 8d.
In this embodiment, the casting pins 8a, 8c, 8b and 8d are pulled out in this order.

As shown in FIG. 3, the drawing device 10 includes a mounting plate 11 mounted on the upper die 7, a cylinder unit 12 pivotally mounted on a side surface of the mounting plate 11, and a rod of the cylinder unit 12. An arm 13 connected to the tip of the arm 12r and a shaft 14 fixed to the arm 13 and extending in the horizontal direction are provided, and the shaft 14 is rotated by the crank motion of the arm 13 by the expansion and contraction operation of the cylinder unit 12. Being free.

Further, fan-shaped pinion gears 15 are attached to both ends of the shaft 14, and the pinion gears 15 mesh with a rack gear 16g of a sliding plate 16. When the shaft 14 rotates, the sliding plate 16 moves up and down by the action of the pinion gear 15 and the rack gear 16g.

Further, as shown in FIG. 4, the sliding plate 16 is provided with groove-shaped holding portions 17a to 17d for holding the four casting pins 8a to 8d,
The casting pins 8a to 8d are provided in the holding portions 17a to 17d.
The base end side flange portion f is fitted and held. The cast-out pins 8a to 8d held by the holding portions 17a to 17d project into the cavity C when the sliding plate 16 descends, and retreat to the outside of the cavity C when the sliding plate 16 rises. .

Further, the holding portions 17a to 17d are formed with a clearance stepped portion d for giving a time difference to the pulling start timing when pulling out the casting pins 8a to 8d. That is, the flange portion f of the cast-out pin 8a that is first drawn out is in close contact with the holding portion 17a without a gap, but the flange portion f of the cast-out pins 8b to 8d that is drawn out after the second portion and the holding portions 17b to 17d. A gap step portion d is formed downward between the gaps, and the gap interval of the gap step portion d is made to sequentially increase in accordance with the drawing order.

Further, the clearance step portion d of the cast pin 8d to be finally pulled out has such a clearance amount that the pin 8d completely comes out of the cavity C when the sliding plate 16 reaches the rising end. . By the way, mounting plate 1
A collar 18 capable of inserting and guiding each of the casting pins 8a to 8d is attached to 1.

The operation and the like of the pulling device 10 as described above will be described. As shown in FIG. 1, the cores 3 and 4 are set on the lower mold 2, the left and right sliding molds 5 and 6 are slid, and then the upper mold 7 is lowered to close the mold. And FIG.
As shown in (b), the cylinder unit 12 of the drawing device 10 is retracted to lower the sliding plate 16,
The four casting pins 8a to 8d are inserted into the cavity C.

Next, when the molten aluminum is poured from the pouring port 9 and cast and the molten metal solidifies, the cylinder unit 12 of the drawing device 10 is extended to move the sliding plate 16 as shown in FIG. 3 (a). To raise. Then, the casting pins 8a, 8c, 8b, 8d are sequentially withdrawn with a time lag in the ascending order of the clearance step portions d of the holding portions 17a to 17d, the pulling resistance is dispersed, and defects such as galling are suppressed.

At the time when the sliding plate 16 is completely raised, that is, when the casting pin 8a is first pulled out.
When the drawing is completed, all the drawing pins 8a to 8d including the final drawing pin 8d have been drawn, and the drawing is completed in the same cycle as the conventional one, so that the work efficiency is reduced. There is no inconvenience. Then, when the drawing of the casting pins 8a to 8d is completed, the mold is opened and the product is taken out.

With the above procedure, the casting pin 8a
It is possible to smoothly pull out ~ 8d, and it becomes possible to prevent problems such as breakage of the shaft, and moreover, conventional equipment can be utilized to the maximum extent.

The present invention is not limited to the above embodiment. Those having substantially the same configurations as those described in the claims of the present invention and exhibiting the same operational effects belong to the technical scope of the present invention.

[0026]

As described above, according to the present invention, when a product having a plurality of casting holes is cast by a plurality of casting pins and then the casting pin is pulled out, there is a time difference between the start timings of the drawing pins. Since it has it, the load due to the pull-out resistance is dispersed and at the same time it is possible to prevent an excessive load from being applied.
In addition, it is possible to prevent galling and the like and smoothly pull out. In addition, the cycle time required for conventional drawing is increased by making sure that the drawing pin that started drawing last is completed when the drawing pin that started drawing first completes drawing. Without deteriorating work efficiency. And as a pulling device,
It is preferable to provide a plurality of holding portions on the sliding plate so that the casting pin can be held by these holding portions, and a gap step portion is provided on the holding portion. As a sliding mechanism, a shaft that can be rotated by the operation of the cylinder unit is provided, and if the rotation of this shaft is converted into sliding of a sliding plate by a pinion rack mechanism, existing equipment can be maximized. It can be utilized and can be constructed at a lower cost.

[Brief description of drawings]

FIG. 1 is a schematic view of a casting mold to which a casting pin drawing device according to the present invention is applied.

FIG. 2 is a main view of the sliding plate and the cast pin as seen from the front.

FIG. 3 is an operation diagram of a drawing device.

FIG. 4 is an explanatory diagram of a clearance step portion of a sliding plate.

FIG. 5 is an explanatory view of a conventional drawing device.

[Explanation of symbols]

8a to 8d ... Cast pin, 10 ... Extractor, 12 ... Cylinder unit, 14 ... Shaft, 15 ... Pinion gear, 16 ... Sliding plate, 16g ... Rack gear section, 17
a to 17d ... Holding portion, d ... Clearance step portion.

Claims (3)

[Claims] 1. A drawing method for drawing a casting pin after casting a product having a plurality of casting holes with a plurality of casting pins, wherein the drawing start timings of the plurality of casting pins differ by time. In addition, when the casting pin that first started drawing has completed drawing, the drawing pin that started drawing last is completed and pulled out from the product. A method for pulling out a casting pin from a casting die. 2. A pulling device for pulling out a plurality of casting pins that can be inserted into a cavity of a mold, the sliding plate having a plurality of holding portions for holding the plurality of casting pins. And a slide mechanism for moving the sliding plate by a stroke, whereby the casting pins are pulled out by moving the sliding plate in a stroke in a predetermined direction. An apparatus for extracting a casting pin, characterized in that a clearance step portion is formed in the holding portion so as to make a time difference between the extraction start timings of the respective casting pins. 3. The sliding mechanism includes a cylinder unit attached to a mold side, a shaft rotatable by the operation of the cylinder unit, and a pinion for converting the rotation of the shaft into a slide of the sliding plate. -The casting pin drawing device according to claim 2, further comprising a rack mechanism.