JPH0120044Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mold release device for shell cores. This is used in the field of mold release after molding of cores that have gas vent holes that allow gas generated from molding sand to be drawn out during casting.

[Prior art]

Used as a mold release device for shell cores in 1982.
Some are described in Publication No. 122747. This is because the eject plate, which has an eject pin attached to the back side of the mounting plate of the core mold, which passes through the mounting plate and the lower mold and reaches the cavity end of the mold, is attached to the back side of the mounting plate of the core mold. It is provided so that it can move toward and away from the camera. A displaceable gas vent pin is inserted through the entire longitudinal direction of the eject pin.

According to such a mold release device, before the shell core molded in the cavity is released from the mold by the eject pin, the degassing pin protruding into the shell core from the upper end of the eject pin is pulled out from the lower mold. It is necessary to separate it from the shell core. The lower end of this degassing pin is pushed up by the other arm of a rotating member, one arm of which is biased by a spring. When one arm is pushed up against the spring by the push-up plate provided below the eject plate, the rotating member rotates and the other arm moves in the opposite direction, causing the degassing pin to remain stationary. Down the inside, the gas vent pin separates from the shell core. after that,
When the push-up plate is further raised to push up the entire eject plate, the upper end of the eject pin pushes up the end of the shell core, so that the shell core is released from the cavity.

By the way, the diameter of the gas venting pin is 3 mm or less, and it is a thin and tapered needle shape, and since the ejecting pin that moves up and down through the eject plate is long, the gas venting pin that passes vertically through the eject plate and is displaced is also long. . Therefore, the degassing pin has a shape that is easily deformed and easily broken. The portion of such a pin that passes vertically through the eject pin is guided by the hole, but the portion below the eject plate to which the eject pin is attached is exposed. As a result, when the eject pin is moved up and down by the rotating member, it is deformed by the pushing up force, and there is a problem that the up and down movement is inhibited and often breaks.

[Purpose of invention]

The present invention was developed to solve the above-mentioned problems, and its purpose is to avoid deformation or breakage of the degassing pin that requires relative movement within the eject pin, and to prevent the degassing pin from deforming or breaking from the shell core of the degassing pin. An object of the present invention is to provide a mold release device for a shell core, which can smoothly release the shell core from the mold and release the shell core from the cavity using an eject pin.

[Structure of the idea]

The features of the shell core releasing device of the present invention are as follows.

(i) On the back side of the mounting plate of the core mold,
An eject plate provided with an eject pin facing the cavity of the mold is disposed so as to be movable toward and away from the mold.

(ii) The eject pin has a vertical hole that runs vertically in its upper half and opens at the upper end, and a notched groove that communicates with this vertical hole in the middle of the eject pin and extends in the longitudinal direction of its lower half. It is formed.

(iii) A substantially L-shaped degassing pin is attached to the mounting plate and inserted into the vertical hole from the end of the notch groove.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples thereof.

FIG. 1 is a sectional view showing the main parts of the mold release device. In the figure, 1 is a mold in which a cavity 3 for molding a shell core 2 is formed, and a lower mold cooperates with an upper mold (not shown). . 4 is the mounting plate of this mold 1,
Reference numeral 5 denotes an eject plate which is disposed on the back side of the mounting plate 4 so as to be movable toward and away from the mold 1 using an air cylinder (not shown), and 6 is an eject plate which passes through the mounting plate 4 and faces the mold 1. This is an eject pin provided on the eject plate 5. 7 is a vertical hole extending in the axial direction of the upper half of the eject pin 6 and opening at the upper end 6a;
Reference numeral 8 denotes a notch groove that communicates with the vertical hole 7 at the middle portion of the eject pin 6 and is formed in the longitudinal direction of the lower half thereof. The cross-sectional shape of the eject pin 6 at the notched groove 8 is opened and cut out in the radial direction, as shown in FIG. 2, for example. Reference numeral 9 shown in FIG. 1 is a substantially L-shaped degassing pin inserted into the vertical hole 7 from the end of the notch groove 8, and one piece 9A of the pin is inserted into the mounting plate 4 through two backing plates 10A and 10B. It is fixed with bolts 11A and 11B. Note that the tip 9a of this gas vent pin 9 is
It is formed into a needle shape to facilitate separation from the shell core 2, and the diameter of the sliding portion located within the vertical hole 7 is approximately constant. In addition, the end surface 10a and side surface 10b of the backing plate 10B that enter the notch groove 8 (see FIG. 2)
and the inner surface 8a of the notch groove 8 are formed to be slidable.

According to the embodiment with such a configuration, the shell core 2 is molded in the mold 1 as follows, and
The degassing pin 9 can be separated from the shell core 2 and the eject pin 6 can be used to release the shell core 2 from the cavity 3.

As shown in FIG. 1, an eject pin 6 and a degassing pin 9 are placed in a mold 1, an upper mold (not shown) is placed thereon, and then molding sand is blown into the cavity 3. After the shell core 2 is molded, the upper mold is removed, and an air cylinder (not shown) is slightly extended to raise the eject plate 5 slightly. The gas vent pin 9 is attached to the mounting plate 4 with bolts 11A, 1.
1B, the eject pin 6 slides with the gas vent pin 9 on the inner surface of the vertical hole 7, and the inner surface 8a of the notch groove 8 is connected to the protruding end surface 1 of the backing plate 10B.
0a and the side surface 10b, the arrow 12
move in the direction. As a result, the upper end 6a of the eject pin 6 pushes up the shell core 2 in the cavity 3 a little, and the stationary gas vent pin 9 is separated from the shell core 2. When the air cylinder is further extended, the inner surface 8a of the notched groove 8 of the eject pin 6 slides on the gas vent pin 9 and the backing plate 10B and moves upward in the direction of arrow 12, and the shell core 2 moves around the cavity 3. The mold is released along the draft slope. This shaped shell core 2 is separately taken out and used as a core during casting. At that time, from the gas vent hole formed in the core 2,
Gas generated from the molding sand is extracted by the heat of pouring,
Deformation and collapse of the core 2 are prevented. Note that although the movement of the eject pin 6 has been described in the vertical direction, it is of course applicable to horizontal movement as well, and in short, it only needs to be able to move toward and away from the mold 1.

With the above configuration and operation, the thin and easily broken gas vent pin can be shortened, and
Since there is no need to move it itself, deformation and breakage of it can be suppressed. Furthermore, the length of the sliding part of the eject pin with the gas vent pin in the vertical hole is shortened, and the gas vent pin itself is shortened and its rigidity is improved, so the amount of deformation of the gas vent pin is extremely small. Separation from the shell core is performed smoothly. Further, the release of the shell core from the cavity by the eject pin becomes even smoother. In addition, since the only movable part in the device is the one that operates the eject pin, the structure of the mold release device is simplified and an inexpensive shell core mold release device can be achieved.

[Effect of idea]

As explained in detail in the above embodiment, the present invention has a gas vent pin fixedly provided on the back side of the mounting plate of the mold, and an eject pin that slides on this. When separating from the core and when releasing the shell core from the cavity, it is only necessary to move the eject pin, and deformation or breakage of the gas vent pin can be avoided. In addition, since the degassing pin itself becomes shorter, its rigidity increases, and even if some external force is applied, the degree of deformation can be suppressed to a small extent, and it can be used for a long period of time without causing a situation such as breakage.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a mold release device which is an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line -- in FIG. 1...mold, 2...shell core, 3...cavity,
4... Mounting plate, 5... Eject plate, 6... Eject pin, 6a... Upper end of eject pin, 7... Vertical hole, 8... Notch groove, 9... Gas venting pin.

Claims (1)

[Scope of Claim for Utility Model Registration] An eject plate, which is provided with an eject pin facing the cavity of the mold, is arranged on the back side of the mounting plate of the core mold so that it can move toward and away from the mold. A vertical hole is formed in the eject pin, and a vertical hole is formed in the upper half of the eject pin and opens at the upper end, and a notch is formed in the vertical hole in the middle of the eject pin and extends in the longitudinal direction of the lower half of the eject pin. A releasing device for a shell core, characterized in that a substantially L-shaped degassing pin is attached to the mounting plate and is inserted into the vertical hole from the end of the notched groove.