JPS6264450A - Method for joining patterns for lost wax - Google Patents

Abstract

PURPOSE:To form a pattern which has excellent dimensional accuracy and has no projecting parts to joint surfaces by forming a recess o the joint surface of a split pattern, forming a passage communicating with the recess to one pattern and injecting an adhesive agent through the passage in the stage of bringing both patterns into press contact with each other. CONSTITUTION:The adhesive agent passage 11a is formed to an upper part 5a of each post part of the 1st split pattern 11 and the recess 12 is provided atop 5b' the lower part 5b of each post part 5 of the 2nd split pattern 12 so as to face the passage 11a. Both patterns 11, 12 are brought into contact with each other and are pressed from a vertical direction so that the respective contact surface 5a', 5b' contact with each other under the pressure. The adhesive agent is forced and injected from a nozzle 14 into the passage 11a formed to the 1st pattern 11. The adhesive agent is introduced through the passage 11a into the recess 12a by which the surfaces 5a', 5b' are joined and a wax pattern 1 is completed. The product having the high dimensional accuracy and the good molding surface is obtd. the using such wax pattern 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a) a method for joining divided wax models used in the lost wax method, which is a type of U 31 method.

(Prior Art) A method called a lost wax method is known as a type of H7M method. This method has excellent features such as being able to obtain products with excellent dimensional accuracy and a good cast surface, as well as being able to manufacture products with complex shapes and thin walls.The general steps are as follows: It is as follows.

First, a plurality of models with the same shape as the product to be manufactured are formed using a mold using wax, and these wax models are also used as a tree part made of wax (this tree part is used as a runner during casting). ) to create a collection of models. Next, this model assembly is alternately subjected to a dipping process using a liquid slurry material consisting of, for example, fine zircon sand and colloidal silica as a binder, and a sanding process using, for example, alumina sand. Multiple coating layers are formed around the aggregate. After drying this coating layer, the model assembly made of wax is melted and removed by dewaxing treatment using steam heating, for example, and the hollow body made of the above-mentioned coding layer obtained by this dewaxing treatment is fired. Ceramicize. As a result, a mold having a plurality of cavities corresponding to the shape of the model and runners communicating with these cavities is obtained.

Next, molten metal is poured into the mold thus obtained in the same manner as in a normal casting method, and when the molten metal solidifies, the mold is broken up by applying vibrations, thereby forming the above-mentioned model assembly. Cuts intermediate products of the same shape. Finally, a plurality of products are obtained by separating each product part from the lagoon part of this intermediate product.

However, in this lost wax method, as mentioned above, a wax model corresponding to the product shape is first created, but depending on the shape, it may not be possible to create it with a pair of opening and closing molds due to the cutting process. be. In such a case, a core will be incorporated into the mold, but when making this wax model, only the core must be melted and removed after the mold is dismantled, so a special liquid-soluble material cannot be used in the φ center. child is used. However, this material is extremely expensive and has the disadvantage that the gases generated during melting degrade the working environment. Therefore, a wax model is divided into a plurality of parts and molded individually, and after molding, an adhesive is applied to the divided surfaces of these divided parts to bond them together. However, even with this method, dimensional errors occur due to the adhesive layer interposed between the joint surfaces of each divided model, and the adhesive protrudes from between the joint surfaces, and this protruding area remains undesired in the final product. This has the disadvantage that it appears as a protrusion, which impairs the advantages of the lost wax method, such as excellent dimensional accuracy and the ability to obtain a good molding surface.

(Object of the invention) The present invention relates to a wax model used in the lost wax method,
In particular, this method deals with the above-mentioned situation regarding the creation of models whose shapes cannot be made with a single set of molds due to the cutting process. By improving the model joining method, it is possible to create a model with excellent dimensional accuracy and no extra protruding parts at the joints. The purpose of this is to make it possible to obtain a product having high dimensional accuracy and a good molding surface even if the overall shape of the model-beaten product is a shape that cannot be cut out.

(Structure of the Invention) That is, the present invention relates to a method for joining each divided model when a wax model used in the lost wax method is created by joining a plurality of divided models.
A recess is formed in at least one of the joining surfaces of the split models to be joined, and a passage leading to the recess is formed in one of the split models, and the joining surfaces of these split models are brought into contact with each other. It is characterized in that the pressure is maintained, and in this state, the adhesive is injected under pressure into the recess from the passage. According to this method, a pair of split models to be joined is injected from a passage provided in one of the parts into a recess provided between the joint surfaces of both split models, and then the joint is poured from the recess. They will be joined and integrated by the adhesive that seeps out between the surfaces, but in that case, the two divided models are held so that the joining surfaces are in contact with each other under pressure, so the joining is done by injecting the adhesive. The surfaces do not separate, and therefore, the dimensions in the direction perpendicular to the joint surfaces of the split models after joining do not become distorted. In addition, adhesive can be injected without too much or too little by appropriately setting the pressure during injection.
This eliminates the problem of the adhesive spilling out around the joint and creating unnecessary protrusions on the model. As the adhesive, in addition to the original adhesive, a solution of wax, which is the material of the model, can be used.

(Effects of the Invention) As described above, according to the present invention, when a wax model used in the lost wax method is created by joining separately formed divided models, the joining of the divided models to be joined is possible. This will prevent the occurrence of dimensional errors due to the adhesive layer interposed between the surfaces, and the generation of unnecessary protrusions due to the adhesive extruding. As a result, a wax model with excellent dimensional accuracy and a good shape can be obtained, and in turn, a high-quality product can be obtained.

(Example) Examples of the method of the present invention will be described below.

First, the wax model to which this embodiment is applied will be explained. As shown in Fig. 1.2, this wax model 1 is a planetary carrier of a planetary gear mechanism used in automatic transmissions for automobiles, etc. It is used when casting using the lost wax method, and is manufactured in the same shape as the planetary carrier to be manufactured. In other words, this wax model 1
is a hollow first part around which a spline m2a is formed.
A disc part 2, a hollow second disc part 3 disposed concentrically and parallel to the disc part 2, and a cylinder connected to one surface of the second disc part 3. shaped portion 4; Second disc part 2, 3
Both circuit board parts 2 and 3 are erected at three equal positions on the circumference between
It is composed of three wooden support sections 5...5 that connect the. In addition, six holes 2b...2b, 3a...3a into which the shafts are inserted are formed in both the disc parts 2.3 at corresponding positions, and the first disc part 2. 2
The three holes 2b' ... 2b' are surrounded by a second hole.
Boss portions 6 . . . 6 that protrude toward the disk portion 3 are provided.

However, as shown in FIG.
It is created by joining a first divided model 11 whose main part is the disk part 2 and a second divided model 12 whose main part is the second disk part 3. These divided models 11 and 12 are formed separately by a pair of opening and closing molds, and the second
The shape is obtained when the three support columns 5...5 of the wax model 1 as a completed product are cut along the virtual dividing plane X-X shown in the figure. Therefore, the first divided model 11 has a shape in which the boss portions 6...6 and the upper portions 5a...5a of the support portions 5...5 are provided on the lower surface of the first disc portion 2, and The second divided model 12 has a slotted shape in which the lower parts 5b of the support columns 5...5 are provided on the upper surface of the second disc portion 3, and the cylindrical portion 4 is provided on the lower surface.

Then, the upper part 5 of each support column 5 in the first divided model 11
An adhesive passage 11a penetrating in the vertical direction is formed in the upper surface 5b' of the lower part 5b of each branch part 5 in the second split model 12, and a recess 12a corresponding to the adhesive passage 11a is formed in A plurality of slits 12b...12b are provided extending radially from the recess 12a (see FIG. 4).

The first. Next, as shown in FIG.
...5 a + and the upper surfaces 5b' ... 5b' of the support portions 1 parts 5b ... 5b in the second divided model 12 are brought into contact with each other, and in this state, each contact surface 5 a + , 5
Pressure is applied in the vertical direction so that b' is brought into pressure contact.

In addition, prior to this pressurization, the first
．． Positioning jigs 13...13 in the shape of dividing a hollow disk into three equal parts are inserted from three sides between the second divided models 11 and 12,
Adjacent recesses 13a, 13 of the recesses 13a...13a formed at the ends of these jigs 13...13, respectively.
The first 1. 1st division model 1
．． Only twelve lateral alignments are performed.

In this way, the first. When the first divided models 11 and 12 are pressurized and held in a predetermined positional relationship, the upper end of the adhesive passage 11a formed in the upper part 5a of the branch part that goes down to the first divided model 11 A nozzle 14 is connected to the opening, and adhesive is injected through the nozzle 14 under pressure. This adhesive is guided downward in the upper part 5a of the column in the first divided model 11 by the passage 11a, and the lower part of the column in the second divided model 12 that is in contact with the lower surface 5a' of the upper part 5a of the column. The passage 11a is located on the upper surface 5b' of 5b.
Since the recess 12a is numbered at a position corresponding to
will be introduced in In addition, some of the adhesive oozes out from the recess 12a and the sleeves 1 to 12b, . As a result, both light contact surfaces 5ar, 5b
+ is joined, and along with this, the first. Second division model 11
．． 12 are joined and integrated to complete the wax model 1 as shown in FIG. 1.2. In that case, the adhesive is the first adhesive. Both surfaces 5a' of the second split model 11.12 are pressed together (the lower surface of the upper part of the column and the upper surface of the lower part of the column) 5a' and 5b'.

5b', as in the case where an adhesive layer is formed between both bonding surfaces. When the second split model is integrated, the dimension in the direction perpendicular to the joint surface does not become larger than the regular dimension, and by setting the injection pressure to an appropriate level, the adhesive can be applied to the joint surface 5a', 5b', and the adhesive can be supplied between both bonding surfaces 5a'.
, 5b' will not protrude into the surrounding area. As a result, a wax model 1 with excellent dimensional accuracy and no unnecessary protrusions due to adhesive extrusion can be obtained, and by casting using the lost wax method using this wax model 1, a high-quality product can be obtained. will be obtained.

In this embodiment, the recess 12a is provided in the second divided model 12, but it may be provided in the first divided model 11 where the adhesive passage 11a is provided, or it may be provided oppositely in both divided models 11 and 12. It may also be provided.

Further, the slits 12a may be provided as necessary depending on the size, shape, etc. of the recess, and the shape, number, etc. may be set as appropriate.

[Brief explanation of the drawing]

FIG. 1 is a bottom view of a wax model created by the method according to the embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view of the wax model taken along line 1--2 in FIG. Fig. 3 is a longitudinal cross-sectional view of the split model used in the actual flow example C, Fig. 4 is an enlarged plan view of the main part taken from Fig. 3 IV-IV arrows, and Fig. 5 is a longitudinal cross-section showing the joining process of the split model. 6 is a cross-sectional plan view taken along the line Vl-VI in FIG. 5. 1... wax model, 5ar, 5b+... joint surface,
11.12...Divided model, 11a...Passway, 12a
...concavity.

Claims (1)

[Claims] (1) A method of joining divided wax models used in the lost wax method, in which a recess is formed in at least one of the joint surfaces of the divided models to be joined, and one of the divided models is provided with a recess in the recess. In addition to forming a communicating passage, the joint surfaces of these divided models are brought into contact with each other and held under pressure, and in this state, adhesive is injected under pressure into the recess from the passage to join both divided models. A method for joining lost wax models characterized by: