CN110127305A - A variable-pitch helical shaft for aluminum liquid transmission - Google Patents

Abstract

The invention proposes a variable-pitch helical shaft for aluminum liquid transmission. The variable-pitch screw shaft includes screw shaft 1 and screw blade 2; the geometrical shape elements are: screw blade diameter φD, screw shaft diameter φd, screw blade front pitch PⅠ, screw blade rear pitch PⅡ, and screw blade thickness S, helix angle β , the helix angle α at the inner edge of the helical blade; the φD=130mm, φd=40mm, PI=200mm, PII=300mm, S=20mm, α=87°, β=100°; the helical shaft is nitrided Silicon-ceramic composites. The invention adopts the silicon nitride ceramic composite material to make the shape, does not stick to the molten aluminum liquid, and has no pollution to the transportation of the aluminum liquid; after sintering, it is machined, and the helical blade adopts a variable pitch structure, and the pitch of the front end of the helical blade is smaller than that of the rear end of the helical blade. The sliding surface of the aluminum liquid changes and the impurities in the aluminum liquid are discharged, and the transmission of the aluminum liquid is accelerated. It is suitable for application as a screw shaft for aluminum liquid transmission.

Description

A variable-pitch helical shaft for aluminum liquid transmission

technical field

The invention relates to the screw transmission of molten aluminum, in particular to the screw shaft for the transmission of molten aluminum.

Background technique

At present, the transportation of molten aluminum is carried out by transfer ladle. This process is to import the molten aluminum in the smelting furnace into the transfer ladle. The transfer ladle is transported by forklift, and then the aluminum liquid is poured into the final mold to make the product. , the process is accompanied by the loss of the temperature of the aluminum liquid, the aluminum liquid is polluted by unknown impurities in the air during the transportation process, and there are disadvantages such as the cost of personnel and equipment during the transportation process.

Omitting the transfer ladle usually adopts the horizontal screw conveyor transmission method, and its main component is the screw shaft. When the screw shaft of the machine is started to rotate, the material is subjected to the normal thrust of the screw blade, and the axial component of the normal thrust of the blade The bottom moves axially along the material trough, so as to realize the conveying of materials. At present, most of the screw shafts on the market are made of cold-rolled steel. This material is no problem for the transportation of ordinary materials, but for the transportation of high-purity aluminum liquid, it will not only pollute the purity of aluminum water, but also easily deform at high temperatures and shorten the service life. short. Due to the poor toughness of ceramic materials, the processing process is difficult. For complex parts such as the screw shaft, it is easy to break during the processing process, and the angle and pitch of the screw blade must be guaranteed. So there is no ceramic screw shaft on the market at present. Our ceramic materials can not only meet the requirements for transporting molten aluminum, but also will not pollute the purity of molten aluminum. Therefore, it is of great significance to overcome difficulties and develop a high-purity molten aluminum power screw shaft.

Contents of the invention

In order to solve the problem that the liquid aluminum is polluted during the transportation and affects the purity of the aluminum liquid, the present invention proposes a variable-pitch helical shaft for the transmission of the aluminum liquid. The screw shaft is made of silicon nitride ceramic composite material. The variable-pitch screw blade transports the aluminum liquid from one end of the conveyor to the other end at a low speed. The ceramic after sintering has high hardness and does not stick to the molten aluminum liquid. There is no pollution to the transportation of molten aluminum, and the technical problems affecting the purity in the transportation of molten aluminum are solved.

The scheme that the present invention solves technical problem adopts is:

The variable-pitch screw shaft includes screw shaft 1 and screw blade 2; the geometric shape elements are: screw blade diameter φD, screw shaft diameter φd, screw blade front pitch PⅠ, screw blade rear pitch PⅡ, and screw blade thickness S, helix angle β , the helix angle α at the inner edge of the helical blade;

The φD=130mm, φd=40mm, PⅠ=200mm, PⅡ=300mm, S=20mm, α=87°, β=100°;

The screw shaft is made of silicon nitride ceramic composite material;

After the screw shaft is formed and sintered, the screw thread is processed. The combination of the lathe and the milling cutter is adopted. The three-axis linkage of the workpiece rotation axis, the pitch of the hanging wheel is 192mm, the turning degree of the main shaft is 7.5r/min, and the feed speed of each step is slow. The process should be small, and the tool should be changed every 90 minutes. To ensure the accuracy, 0.2mm is reserved, 0.05mm each time, the pitch of the triangular thread hanger wheel is 2mm, and the turning is carried out in ten times.

Positive effect, because the present invention adopts silicon nitride ceramic composite material to make molding, non-stick molten aluminum, no pollution to the transportation of molten aluminum; after sintering, machining is carried out, and the spiral blade adopts a variable pitch structure, and the pitch of the front end of the spiral blade is smaller than that of the spiral blade The pitch of the rear end, the sliding surface of the aluminum liquid changes and the impurities in the aluminum liquid are discharged, and the transmission of the aluminum liquid is accelerated. It is suitable for application as a screw shaft for aluminum liquid transmission.

Description of drawings

Fig. 1 is a cross-sectional view of the structure of the present invention.

In the figure, 1. Screw shaft, 2. Screw blade, φD. Screw blade diameter, φd. Angle, α. Helix angle at the inner edge of the helical blade.

Detailed ways

As shown in the figure, the variable-pitch screw shaft includes screw shaft 1 and screw blade 2; the geometric shape elements are: screw blade diameter φD, screw shaft diameter φd, screw blade front pitch PI, screw blade rear pitch PII, and screw blade thickness S , the helix angle β, the helix angle α at the inner edge of the helical blade;

The φD=130mm, φd=40mm, PⅠ=200mm, PⅡ=300mm, S=20mm, α=87°, β=100°.

The screw shaft is made of silicon nitride ceramic composite material.

After the screw shaft is formed and sintered, the screw thread is processed. The combination of the lathe and the milling cutter is adopted. The three-axis linkage of the workpiece rotation axis, the pitch of the hanging wheel is 192mm, the turning degree of the main shaft is 7.5r/min, and the feed speed of each step is slow. The process should be small, and the tool should be changed every 90 minutes. To ensure the accuracy, 0.2mm is reserved, 0.05mm each time, the pitch of the triangular thread hanger wheel is 2mm, and the turning is carried out in ten times.

Working principle of the present invention:

High-purity molten aluminum has very high requirements on equipment, and it is very easy to be polluted during transportation. The continuous transmission of the spiral shaft structure of the transfer ladle can be omitted, and the transportation, loading and unloading of high-purity molten aluminum can be realized. It can also be completed during the transportation process according to actual needs. Mixing, stirring, heating and other process operations, as well as the delivery of high-temperature materials. The screw shaft has a simple and durable structure, small and compact volume, and is completely sealed to ensure dust-proof and sealed design. The heat of the molten aluminum will not be lost, and the closed transportation can be realized to reduce the pollution of the environment to the molten aluminum.

The nominal diameter of the screw blade φD is an important parameter of the horizontal screw conveyor, which is directly related to the production capacity and structural size of the screw conveyor. If the mass conveying quantity Q is known, the nominal diameter of the spiral blade φD can be estimated according to the formula, and then the calculation can be performed after determining other parameters.

The size of the pitch S determines the size of the helix angle β, and the size of the helix angle directly affects the force component of the aluminum block during the conveying process, and directly affects the conveying state of the aluminum during the conveying process. Moreover, when the delivery volume and screw blade diameter are determined, the screw pitch changes, the filling coefficient also changes, and the sliding surface of the material also changes, which directly affects the conveying process of the horizontal screw conveyor. The pitch of the front section of the screw shaft is PI and the pitch of the rear section is PII. This form is mainly considered to remove impurities in the aluminum liquid and speed up the discharge of aluminum water.

The diameter of the screw shaft journal φd and the pitch jointly determine the size of the helix angle α at the inner edge of the screw blade. The size of the journal is related to the pitch, and its size also determines the slip direction and speed distribution of the material. Therefore, it is necessary to Determine the relationship between the reasonable journal diameter φd and the pitch P. The determination of a reasonable journal-pitch relationship should be considered from the following two aspects: (1) the friction relationship between the helical surface and the aluminum material; (2) the proper distribution of the velocity component.

Advantages of the present invention:

The material of the screw shaft is made of silicon nitride ceramic composite material, which is non-polluting to high-purity molten aluminum, and is also resistant to high temperature and non-stick to molten aluminum, so it solves the problem of easy pollution of high-purity molten aluminum during transportation.

Claims (3)

1. A variable-pitch helical shaft for aluminum liquid transmission, characterized in that: the variable-pitch helical shaft includes a helical shaft (1) and a helical blade (2); the geometric shape elements are: helical blade diameter φD, helical shaft diameter φd, helical blade The pitch of the front end PI, the pitch of the rear end of the helical blade PII, the thickness of the helical blade S, the helix angle β, and the helix angle α at the inner edge of the helical blade; The φD=130mm, φd=40mm, PⅠ=200mm, PⅡ=300mm, S=20mm, α=87°, β=100°. 2. The variable-pitch helical shaft for molten aluminum according to claim 1, characterized in that: the helical shaft is made of silicon nitride ceramic composite material. 3. The aluminum liquid variable-pitch helical shaft according to claim 1, characterized in that: the helical shaft is manufactured and sintered for thread processing, and the lathe and milling cutter are combined, and the three-axis linkage of the rotating shaft of the workpiece is adopted. The pitch of the hanging wheel is 192mm, the turning degree of the main shaft is 7.5r/min, the feed speed of each step is slow and the process is small, and the tool needs to be changed every 90min. To ensure the accuracy, 0.2mm is reserved, 0.05mm each time, the pitch of the triangular thread hanging wheel It is 2mm, and it is turned in ten times.