JPH0684025B2 - Mold release method - Google Patents

Description

The present invention relates to a mold releasing method of a casting mold which is a simple mold for high-mix low-volume production.

(Prior art) Conventionally, this type of mold release method is to inject the mold material onto the model, perform vacuum defoaming, and then gradually raise the temperature of the model and the mold material in the furnace. The model is released when the casting material is semi-cured. In this case, a mold release material is generally applied to the model so as to facilitate the mold release, but the casting material is in close contact with the model, and often the model does not come off even if the model is simply pulled.

Therefore, as shown in Fig. 6 (a), put the backup material 14 on the back surface of the model 2,
A bolt hole is formed in it, and it is pulled out via the bolt 15. Alternatively, as shown in FIG. 6 (a), the ejector pin 16 is used to push out the model 2.

(Problems to be Solved by the Invention) However, these methods have problems that the casting mold 1A is damaged or the surface is scratched when the model 2 is released.

Further, the back side cannot be used as the model 2 in the above method. In addition, the method (1) has a drawback that the projection 1A 'has a hole and needs to be filled in after that, and the appearance is deteriorated in quality.

The present invention has been proposed in view of the above, and an object of the present invention is to solve the problem of mold release, which is a defect in the conventional method, and improve the productivity and quality of the casting mold. The object is to provide a mold release method.

(Means for Solving the Problems) In the present invention, in a mold releasing method of a casting mold in which a casting mold cast on a model is semi-cured and then the model is released, A water-soluble natural polysaccharide is added to the model in a casting mold releasing method in which a gap is created between the casting molds of the model by generating a slight relative motion between the casting molds and the model is released. The above-mentioned object is achieved by applying, casting a casting material from above, solidifying the casting material, dissolving the water-soluble natural polysaccharide with water, and providing a gap between the model and the casting mold. .

(Operation) In the present invention, the mold releasability is improved by providing a gap between the model and the casting mold, thereby facilitating the manufacturing of the casting mold and improving the quality.

(Example 1) FIG. 1 is a conceptual diagram showing the basic principle of the present invention. In the present invention, as described above, between the model 2 and the casting material 1 until the casting material 1 is semi-cured. By making a slight relative movement in the drawing, a minute gap g is provided between the casting material 1 and the model 2 as shown in FIGS.

FIG. 2 shows the relationship between the temperature and the viscosity until the casting material 1 is semi-cured. Then, the solid line shows the temperature with respect to time and the chain double-dashed line shows the viscosity with respect to time. According to this method, the above-mentioned relative movement is performed until semi-curing progresses and reaches a certain viscosity.

FIG. 3 is a conceptual diagram of the first embodiment of the present invention, in which each figure shows an apparatus for carrying out the method. First, in the figure, 3 indicates a substantially rectangular frame, and the frame 3 is a side frame provided on each side.
3a, a lower frame 3b and an upper frame 3c provided therebetween, and for example, a vibrating element controlled by the control unit 4 at an appropriate position on at least one of the side frame 3a and the upper frame 3c
5a is provided, and the vibrating portion 5a ′ of these vibrating elements 5a is attached to the frame 3
It is configured to project inward and to transmit vibration inward.

FIG. 4 shows a casting device having a frame 3 provided with the above-mentioned vibrating element 5a, 6 is a reference plate provided between and below the side frames 3a, and 7 is a slide plate above it. The reference plate 7 is movably provided, and the reference plate 7 is attracted to the lower reference plate 6 side by an elastic body 8 such as a spring.
That is, the elastic body 8 is disposed in the through hole 6a formed in the substantially central portion of the reference plate 6, and the upper end of the elastic body 8 is appropriately engaged with the lower surface of the reference plate 7 through the through hole 6a formed in the vertical direction. And the lower end of the elastic body 8 is a locking tool 6b provided on the release surface of the reference plate 6.
Is locked to.

Further, a ball bearing 9 is provided between the reference plate 6 and the reference plate 7, and a clearance C is provided between the reference plate 7 and the side frame 3a so that the reference plate 7 can move smoothly. Is configured. In order to prevent the casting material 1 from entering the clearance C, an elastic body 10 such as heat resistant rubber is provided around the frame 3. This elastic body 10
Further, by restraining the reference plate 7 with the elastic body 10, it also has a role of improving centripetal force when the exercise is performed.

Then, the vibrating element 5a is provided below the side frame 3a constituting the frame 3.
Is provided, and its vibrating portion 5a 'comes into contact with the side end of the reference plate 7, whereby the reference plate 6 can vibrate in the X direction.

Although not shown, the vibrating element 5a is provided on the reference plate 6, and the vibrating element 5a is brought into contact with the lower surface of the reference plate 7 provided thereon to vibrate the reference plate 7 in the vertical direction, that is, the Y direction. It is also possible to do so. Then, while the casting material 1 is semi-cured, the model 2 vibrates the reference plate 7 provided on the upper side, and if a slight relative movement is caused between the model 2 and the casting material 1, both There is a gap between them, which facilitates mold release, and therefore does not deteriorate the appearance.

In this embodiment, the relative movement between the model 2 and the casting material 1 uses the vibrating element 5a as described above, and the amplitude and frequency are controlled by the control unit 4 shown in FIG. Further, if the vibrating element 5a is independently arranged in the X and Y directions, the motion pattern can be arbitrarily selected,
You can select the optimal pattern depending on the shape of the model such as circle, corner, polygon.

(Embodiment 2) FIGS. 5 to 5 show a second embodiment of the present invention. In this embodiment, as shown in FIG. 5, first, as shown in FIG. Polysaccharide 11,
It is sprayed by the spray device 12 to be evenly applied and dried. Next, as shown in the figure, the casting material 1 is poured onto the model 2.

Then, after the casting material 1 is cured, as shown in the same figure, if it is soaked in water H and left for several hours, the water-soluble natural polysaccharides 11 will be dissolved, and between the model 2 and casting mold 1A A gap g is formed to facilitate mold release. In this case, vibration is applied to the model side and / or the water H or the container 13 side through an appropriate means such as using a vibrating element, that is, a slight relative movement is generated to make the water-soluble natural polysaccharide 11 more positive. Alternatively, a gap g may be provided between the model 2 and the casting mold 1A by being melted.

In the above example, the model 2 needs to be made smaller in consideration of the thickness of the water-soluble natural polysaccharide 11. Further, although the water-soluble natural polysaccharide 11 was used in this example, it is not necessary to limit to this, and it can be uniformly applied to the model 2.
Any other solvent may be used as long as it can be dissolved in some solvent (one that does not dissolve the casting material).

(Effects of the Invention) As described above, according to the present invention, in a mold releasing method of a mold, wherein a mold cast on a model is semi-cured, and then the model is released. By creating a small relative motion between the model and the casting mold, a gap is created between the model and the casting mold, or in the casting mold releasing method of releasing the model, Applying water-soluble natural polysaccharides, pouring a casting material from above, after solidification of the casting material, the water-soluble natural polysaccharides are dissolved in water, because a gap is provided between the model and the casting mold, Since a gap can be provided between the model and the casting mold, it is possible to perform mold release extremely easily, which enables stable production of the casting mold and prevents damage and damage to the casting mold. This has the effect of suppressing and improving the appearance quality of the protruding portion.

[Brief description of drawings]

1 is an explanatory view of the principle of the present invention, FIG. 2 is an explanatory view showing the relationship between temperature and viscosity until the casting material is semi-cured, and FIG. 3 is a conceptual view of the first embodiment of the present invention. FIG. 4 shows the first embodiment of the present invention, FIGS. 5 to 5 are process drawings of the second embodiment of the present invention, and FIGS. 6 (a) and 6 (a) show a conventional example. 1 ...... cast material, 2 ... model 3 ... frame, 4 ... control unit 5a ... vibration element, 6,7 ... reference plate 8,10 ... elastic body, 9 ... ball bearing 11 ... water soluble Natural polysaccharides

Claims (2)

[Claims] 1. A method of releasing a casting mold in which a casting mold cast on a model is semi-cured and then the model is released. In the semi-curing process, a small amount of space is left between the model and the casting mold. A mold releasing method for a casting mold, characterized in that a relative movement is generated to form a gap between the model and the casting mold to facilitate the mold releasing. 2. In a casting mold releasing method for releasing a model, a water-soluble natural polysaccharide is applied to a model, a casting material is poured over the model, the casting material is solidified, and then the water-soluble natural polysaccharide is added. A mold releasing method of a casting mold, characterized in that it is dissolved in water and a gap is provided between the model and the casting mold to facilitate the mold releasing.