JPS6338063Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mold making device for manufacturing a mold using casting sand.

Conventionally, this type of molding equipment fills the mold flask on the model plate with sand and makes the mold using the model on the model plate, so the mold is made by lowering the model plate or raising the mold flask. Due to the precision of the punching process, the corners of the mold may be missing or damaged, which can affect the quality of the product, which is a major problem. In other words, in the mold cutting process, if the movement in the cutting direction is not performed accurately and there is lateral vibration, the model and mold will collide with each other, resulting in mold drop-off, frequent mold build-up, and poor mold rise, which will result in poor cast products. However, there were drawbacks such as the formation of flash and an increase in sand-filling defects. Therefore, as a way to prevent such drawbacks, for example, Jikosho
There is one disclosed in Publication No. 51-29296. That is,
By protruding multiple shaft pins with a draft angle smaller than that of the model around the model on the model mounting surface plate, when removing the model from the mold,
This is intended to prevent collisions between the model and the mold. However, if such a configuration is adopted,
Since the model must always have a draft angle larger than the draft angle of the shaft pin, the degree of freedom in model design is hindered and the production of cast products is severely restricted.

The present invention was developed in view of these circumstances, and it not only improves the precision of mold cutting and makes it possible to produce molds with good mold quality, but also improves the draft angle of the model like the conventional shaft pins mentioned above. It is an object of the present invention to provide a mold making device in which the production of cast products is not restricted by restrictions.

In order to achieve the above-mentioned purpose, the mold making device of the present invention has a
Straight rods having guide surfaces of uniform thickness extending in the drawing direction without applying a draft angle are provided at appropriate locations, and an axial through hole is formed in the straight rods.

Embodiments of the present invention will be described below with reference to the drawings. In this invention, casting sand 5 is placed in the mold flask 2 of the model board 1.
In an apparatus for manufacturing mold A using a model 1a on a model board 1, a thickness that extends in the drawing direction without applying a draft angle is filled in a position corresponding to the inside of the mold flask 2 on the model board 1. It is made up of straight rods 3a having uniform guide surfaces 3 arranged in an appropriate manner.

To explain this in detail, an example of a continuous mold making apparatus to which the present invention is applied is shown in FIGS. 1 to 3. In this apparatus, mold flasks are continuously conveyed on a roller conveyor 4. 2...is model 1
A is placed on the model board 1 surrounding the mold, and the mold flask 2 is filled with casting sand 5. After that, the casting sand 5 is tamped to a suitable hardness and molded. The mold A is completed by cutting out the model 1a from the molded sand 5. The series of operations for molding the mold A is then repeated to continuously mold a large number of molds A. The mold A formed in the mold flask 2 in this way moves together with the mold flask 2 onto the roller conveyor 4 to a desired location (for example, after being matched with a mold formed in another process, pouring is performed. location).
In other words, the roller conveyor 4 is connected to the cylinder (not shown) in conjunction with the molding operation of the mold A described above.
The mold flasks 2 are intermittently driven to travel, and each mold flask 2 is stopped in sequence at the mold-making work position B. Moreover, the model board 1 has, for example, four models 1a... and these models 1a on the top surface.
...a runner forming member 1b for forming a runner between;
1c, and the lower surface of the model board 1 has a piston fitted into, for example, a cylinder (not shown) and driven up and down by hydraulic or pneumatic pressure in conjunction with the driving operation of the roller conveyor 4. It is connected to the upper end of the rod 6. That is, this model board 1 has pins 1 that are inserted and removed in correspondence with pin receiving holes 2a and 2a provided in front and rear of the mold flask 2 that is stopped at the mold-making work position B of the roller conveyor 4.
c, 1c are fixedly installed upright. Furthermore, guide surfaces 3, 3 are provided on the model board 1 at positions spaced a predetermined distance outward from the models 1a, which extend in the drawing direction of the model board 1 without applying a draft angle. These guide surfaces 3, 3 are straight rods 3 that have the same circular cross section over the entire length without applying a draft angle.
It is formed with outer surfaces of a and 3a. A through hole 3b penetrating from the tip to the lower surface of the model board 1 is provided at the axial center of each of the straight rods 3a, 3a. Furthermore, these straight bars 3
For example, a and 3a are located at a predetermined distance from the model 1a... and the channel forming member 1b, and on the model board 1, so as not to affect the molding and pouring, considering the positional state of the model 1a... and the channel forming member 1b. It is placed at an appropriate position corresponding to the inside of the mold flask 2 placed on the mold flask 2.

Next, the operation of forming a mold using the apparatus configured as described above will be explained based on FIGS. First, the model board 1 is raised by the piston 6, and with the pins 1c, 1c of this model board 1 inserted into the pin receiving holes 2a, 2a of the mold flask 2 and positioned, the models 1a... Road forming member 1b
Then, the mold flask 2 is placed surrounding the straight rods 3a, 3a (see the same figure). Then, casting sand 5 is put into the mold flask 2 on this model board 1 (see the same figure). When the casting sand 5 has been poured, the model board 1 is further raised, and a hole is formed that vertically passes through the center of the sprue forming part 9 that is fitted into the upper end of the sprue forming member 1b to form a sprue. Appropriate means such as compressing the casting sand 5 in the mold flask 2 with a squeeze head 7 provided with holes 7a are applied to ensure that the casting sand 5 has sufficient mold hardness (see the same figure). Next, in order to cut out the model board 1 from the mold A, a vibrator 8 applies fine vibrations to the model board 1, and the model board 1 is lowered to separate the casting sand 5 and the model 1a. Then, the mold flask 2 is again supported on the table roller 4 (see the same figure). When the model board 1 is further lowered from this state, the models 1a... and the channel forming member 1b
is moving away from the casting sand 5 of mold A (the same figure,
). During this mold removal process, since no draft angle is applied to the guide surfaces 3, 3, the guide surfaces 3, 3 are guided by the mold A until the guide surfaces 3, 3 are completely removed from the mold A, and the model 1a... and channel forming member 1
b, 1c do not move laterally with respect to mold A,
Can be cut out. Therefore, there is no mold drop or mold build-up caused by lateral vibration during mold cutting. Furthermore, since the guide surfaces 3, 3 slide on the surface of the casting sand 5, there is less wear compared to a mating member made of metal, and the guide surfaces 3, 3 are worn and the straight bar 3
Even if the outer diameters of the straight rods 3a and 3a become smaller, as long as straight portions without drafting are secured, the accuracy will not decrease with use, and the number of repairs such as replacing the straight rods 3a and 3a can be reduced.

Moreover, straight bars 3a, 3 having guide surfaces 3, 3
By providing through holes 3b in each a,
Air can be supplied to the tip cavities 10 of the straight rods 3a, 3a formed during die cutting, and die cutting can be performed without resistance. Also, by sending pressurized air through the through hole 3b, the straight rods 3a, 3
It is also possible to pressurize the tip cavity 10 of a to make die cutting easier.

In addition, in the above embodiment, the guide surfaces 3, 3 were formed with two straight rods 3a, 3a;
The guide surface may be formed by a book or three or more straight rods. Further, the height of the guide surfaces 3, 3 may be sufficient as long as the mold A and the model 1a are separated by a predetermined distance, and it is not necessarily necessary to use the long straight rods 3a, 3a as in the illustrated example. Furthermore, the shape of the straight bar 3a may be any shape, regardless of whether it is a cylinder or a polygonal column, as long as it has guide surfaces 3, 3 extending in the drawing direction without creating a draft on the model board 1. Furthermore, the shape of the straight bar 3a may be chamfered at the upper or lower end as shown in FIG. 4 to facilitate die cutting.

As explained above, the present invention is a device that fills the mold flask on the model board with casting sand and creates a mold using the model on the model board. Straight rods with guide surfaces of uniform thickness that extend in the drawing direction without applying a draft angle are provided at appropriate locations, and a through hole in the axial direction is formed in the straight rods, so that the mold can be easily molded to the model. When pulling out the mold, air is supplied from the through hole to the tip of the straight rod, and even if the straight rod has a guide surface of uniform thickness, the straight rod can be easily pulled out from the mold. At the same time, while the model is being removed from the mold, since the guide surface does not have a draft angle, the guide surface is guided by the part of the mold that faces it, and the model and channel forming member are held in the mold. There is no sideways movement. Therefore,
In the case of the present invention, a mold with good mold quality can be produced without mold drop or mold build-up caused by lateral vibration during mold cutting.

Moreover, in the case of the present invention, the guide surface of the straight bar has a uniform thickness, and the straight bar can be removed from the mold without creating a draft angle, so the model design can be adjusted using the shaft pin as in the conventional method. The degree of freedom is not inhibited, and the influence on the manufacturing (shape) of the cast product can be avoided.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention, with Figure 1 being a plan view, Figure 2 being a partially cutaway side view of the same, and Figures 3, 3, 3, 3, 3, 3, 5, 3, 3, 3 and 3 showing an embodiment of the present invention. A side sectional view of the main part showing the operation, Fig. 4,
3A and 3B are side views showing other modified examples of the straight bar having a guide surface of the present invention, respectively. 1... Model board, 1a... Model, 2... Molding flask, 3... Guide surface, 3a... Straight bar, 3b... Through hole, 5... Casting sand, A... Mold.

Claims (1)

[Scope of utility model registration request] In a device that fills the mold flask on the model plate with sand and makes a mold using the model on the model plate, the mold is placed in a position corresponding to the inside of the mold flask on the model plate in the drawing direction without applying a draft angle. A mold making device characterized in that straight rods having extending guide surfaces of uniform thickness are provided at appropriate locations, and an axial through hole is formed in the straight rods.