JPS6114907B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to a propeller model that overcomes the limitations of propeller size in producing a fugitive model for precision casting of a marine propeller. Regarding the production method.

(Prior art and its problems) In order to produce a precision casting model of a marine propeller, when obtaining a propeller model using fugitive material,
Conventionally, each of the three or four wings from the central boss,
Since the entire projecting part is manufactured as an integral model with a specified pitch and a specified interval, there is a limit to the size of the propeller that can be obtained, and generally the diameter is 1000 mm.
The size limit is about mm.

The present invention was made in view of the limitations in manufacturing propeller models, and an object of the present invention is to provide a method for easily obtaining a high-precision fugitive model for precision casting, regardless of the size of the propeller. do.

(Means for Solving the Problems) A feature of the present invention taken to achieve the above object is that when manufacturing a fugitive propeller model for precision casting, the blade body and a part of the boss are separated from each other. Separate models of each wing unit are molded, and these split models are assembled on a surface plate, and the propeller pitch is set using the support rod for pitch adjustment formed in advance on the blade body and the bottom surface of a part of the boss, and the blade is assembled. The propeller blade spacing is set by making the mutual spacing of the indexing pins between the blades pre-formed on the main body constant, forming an assembly of split models, and forming a feeder part on the upper surface of the boss of the assembly. The method consists of placing a female mold and pouring a model material into the female mold to integrate the assembly.

(Example) The present invention will be described in detail below with reference to the illustrated embodiments. Fig. 1 shows a split model of one wing made by the method of the present invention, and Fig. 2 shows the assembled state of the split models on a surface plate. There is. In the present invention, unlike the conventional method, as shown in FIG. 1, a divided model 1 is created, each consisting of one blade body 1a and a boss portion 1b following the blade body 1a, depending on the number of blades in the target propeller. ,
Each is molded using a female mold. In the illustrated embodiment, an example of a four-blade propeller is shown, and accordingly, four divided models 1 are molded. Therefore, the boss portion 1b following the blade main body 1a in each model 1 is 1/1/2. It is said to have a segment shape that stops at four circumferences.

At this time, in each split model 1, a support rod 2 for pitch adjustment is integrally formed in advance on the front side of the blade to protrude from the blade main body 1a as shown in the figure, and a pin 3 for indexing between the blades is formed on the back side of the blade. Similarly, it is formed in advance so as to protrude integrally.

In Fig. 1, numeral 4 indicates a core bar inserted into the boss part 1b, and numeral 5 indicates a feeder model to be formed later on the boss part, which is made of a fugitive material that is separated from the split model 1. 7 is a female die for molding the feeder model 5, and 6 is a surface plate. In the present invention, four pieces of the divided model 1, each of which is divided into blades and formed with a portion of the boss in the illustrated example, are assembled on a surface plate 6 as illustrated in FIG.

At this time, the pitch and rake on each wing are
Each mating surface of the boss part 1b in each split model, that is, 0A, 0B, 0C, 0D shown in the second figure, each bottom face of the boss part 1b, and pitch projections formed in advance on the front side of the wing body 1a. This can be easily secured using the support rod 2.

Furthermore, the indexing between the blades can be easily and accurately set by making the mutual spacing between the blade indexing pins 3, which are formed in advance and protruding from the back side of each blade main body 1a, constant. The specific setting method is as follows.
Using a template with positioning holes for determining a predetermined blade spacing, each divided model may be finely adjusted so that each of the blade indexing pins 3 is engaged with the positioning hole. In addition, by using an indexing surface plate that can be rotated at predetermined angles, each divided model is finely adjusted so that the inter-blade indexing pin 3 is sequentially aligned with the positioning reference fixed outside the surface plate during indexing. You may.

After adjusting and setting the first group of four divided models in this way, the female die 7 for molding the riser part is set on the upper shoulder part of the boss part formed by the gathered boss parts as shown in the first figure.
The same material as the model material is poured, and the assembly of these divided models 1 group is integrated via the feeder part 5, and then the support rod 2 for pitching and the indexing between the blades are formed on the wing surface of each model 1. By removing the pin 3, the desired evanescent propeller model can be obtained. In this way, the size of the propeller model to be obtained can theoretically be large without any limit, by forming one group of divided models individually and by assembling them.

In addition, if the propeller has 3 blades, split model 1 will have 3 blades.
The number of divided models is increased or decreased depending on the number of wings so that the boss part 1b has a circumference of 1/3.

(Effects of the Invention) The present invention is as described above, and this type of propeller model is made into a divided model 1 which is divided into blade units, and a support rod for pitch adjustment and a pin for indexing between the blades are attached to this divided model 1 in advance. Because of this provision, the divided model group can be precisely and easily positioned so as to match the external shape of the desired propeller model. In addition, the feeder molding female mold is placed on the top surface of the boss of the assembly of split models positioned on the surface plate, and the model material is poured into the female mold, allowing precise positioning at a predetermined pitch and blade spacing. The assembly can be easily integrated while maintaining the same state, and a fugitive propeller model for high precision precision casting can be manufactured extremely easily. Therefore, unlike in the past, the propeller diameter is not limited to about 1000 mm, and it is extremely easy to cast propellers with larger diameters, and the cost of molding female molds for model production can be reduced to 1/3. The mold cost per propeller can be reduced even in small-volume production, and according to the method of the present invention, the conventional propeller diameter of about 1000 mm can be increased to about 1000 to 2000 mm. Moreover, it is 7 to 8 times heavier in weight, and can also be applied to propellers such as similar marine side thrusters and agitator impellers, with excellent advantages and effects. It is something that has.

[Brief explanation of the drawing]

FIG. 1 is a plan and side view of a divided model of one wing unit according to the present invention, and FIG. 2 is a plan view of the divided model in an assembled state. DESCRIPTION OF SYMBOLS 1...Blade unit division model, 1a...Blade main body, 1b...Boss part, 2...Support rod for pitch adjustment, 3...Blade indexing pin, 4...Core metal, 5...Riser part, 6...Surface plate ,7
...Female die for molding the riser part.

Claims (1)

[Claims] 1. When producing a fugitive propeller model for precision casting, a split model of each wing unit consisting of a wing body and a part of the boss is molded separately, these split models are assembled on a surface plate, and the blade body is pre-assembled. The propeller pitch is set by the formed pitching support rod and the bottom surface of a part of the boss, and the propeller blade spacing is set by making the mutual spacing of the blade indexing pins formed in advance on the blade body constant. The method is characterized by forming an assembly of split models, placing a feeder molding female mold on the upper surface of the boss of the assembly, and pouring model material into the female mold to integrate the assembly. How to make a propeller model.