SU1745733A1 - Method of manufacturing products - Google Patents

Abstract

The use of, manufacturing metal-polymer products by molding predominantly gears of reduced vibroactivity with a reduction in energy consumption with an increase in the physicomechanical properties of the product. SUMMARY OF THE INVENTION: Manufacturing techniques for said products include molding a polymer part from thermoplastic powder when exposed to ultrasonic vibrations with an amplitude of 10 to 60 µm until the melting temperature of the thermoplastic is reached more than 10 K, with volumetric deformation of the polymer part during the cooling process. 2 Cp f-crystals, 5 silt, 4 tabl

Description

The invention relates to the processing of plastics for the subsequent production of metal-polymer products, such as gears with reduced vibroactivity in heavily loaded gears, for example, in lathes.

A known method of manufacturing such articles, in particular gears, in which the gap between the metal hub and the rim is filled with molten polymer. In this method, a granular polymeric material is used, which is pre-melted by means of external heat supply, and then poured into the gap between the metal parts of the product.

However, the manufacture of products in this method is associated with significant energy consumption, as well as the need for additional processing of the polymer part of the product. Also manufactured in a similar way.

gears cannot transmit significant torques, making them impossible to use in power transmissions

Some of these drawbacks can be eliminated by changing the structure of the polymer part of the products. In this method of producing products from polyolefins, impact on the polymer powder is provided by ultrasonic vibrations with a frequency in the range T

25 kHz, which makes it possible to obtain a monolithized billet with an oriented structure. Monolitization with this technology makes it possible to obtain products with improved rates of torque transmission.

However, in the known method, increased energy consumption for the manufacture of metal-polymer products is unavoidable, since it is provided for at the outset to obtain the molded billet (floor 2

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measuring the part of the product), and then obtaining the product by deforming the reheated billet, while partially retaining the orientation of the molecules resulting from the monolithmization of the polymer. Thus, the known technology is also not free from such disadvantages as increased energy consumption and insufficient strength properties of the finished metal products.

The aim of the invention is to improve the physicomechanical properties of metal-polymer products, such as heavily loaded gears, while reducing energy costs.

FIG. Figure 1 shows schematically the initial stage of forming a metal-polymer gear with an annular waveguide supplied; figure 2 - the finished product with a pronounced radial orientation of the macromolecules; FIGS. 3 and 4 show the initial stage of forming the product (gear) with the bearing axis and the resulting finished product, respectively; Fig. 5 is a diagram of the process of obtaining the product.

The proposed method is carried out using the following device.

Elements 1 and 2, of which the metal part of the product consists — in this case, the gear rim 1 and the hub 2 gears — are fixed on the base 3, on top of element 1 there is an overlay 4, and on the element is a sleeve 5. Assembled in this way fixed on the work table 6 and fixed relative to each other in the axial direction. Then, powder 7 of the initial polymer (this could be caprolon, polypropylene, foam plastic, etc.) is poured into the annular gap between the patch 4 and the sleeve 5, as well as between the rim 1 and the hub 2. After backfilling, powder 7 is compacted, for which waveguide 8 can be used, and then a generator is switched on (for example, UZDN-1-142) and the powder is subjected to ultrasonic effect, the time of which is determined by the polymer mass reaching a temperature higher than the melting point of the latter. by 10 K.

Other types of metal-polymer products can be made in the same way, for example, elements of power gears with a supporting shaft, etc. In this case, the design of the technological device and the waveguide 8 accordingly changes.

Under the influence of ultrasound, thermal energy is released, which leads to the melting of particles, and

The melt molecules are best oriented in the direction of the propagation front of the waves emitted by the waveguide for precisely this amplitude range.

In order to qualitatively fill the polymer with all the micro and macro irregularities (roughness of the grooves) of the conjugate surfaces of the metal part of the product, it is necessary to sort the molecules

0 polymer in such a way that they fit uninterruptedly into the gaps between the said irregularities of the metal surfaces. This requirement is ensured by the installation of a waveguide 8, with

5, its radiating surface is positioned normally to the mating surfaces of the metal part of the product. It is the corresponding orientation of the molecules of the polymer part of the products in their interaction with the surface of the metal part of the product that explains the achievement of the objective of the invention — the production of a product with enhanced strength parameters;

5 of the cooling process, further volume deformation, carried out within the limits of a decrease in temperature (calculated from T pl) by 10–20 K, makes it possible to minimize the energy consumption for obtaining the model as a whole.

After completion of the monolitization and volumetric deformation during the cooling process, the finished product is removed from the base 3 and the pad 4 and the sleeve are removed.

5 5.

Studies are being carried out on the possibility of obtaining metal-polymer products according to the proposed method depending on the ultrasound frequency for various raw materials of the polymer part of the product, the data of which are given in Table. one.

A portion of the required mass of the powdered material is subjected to a specific pressure of 0.8 MPa (compaction) followed by ultrasonic treatment at the UZDN-1 unit with a magnetostrictive transducer and a titanium waveguide of a ring shape corresponding to the shape of the polymer part of the product.

The process of thermal effects on the product is depicted in Figure 5 in the form of a time-temperature diagram, in which

5 plot to t.1 shows the process of heating the polymer powder as a result of exposure to ultrasound, and the plot from t. 1 dot. 2 describes the period of complete (guaranteed) melting of the polymer, as a result of which its temperature rises

10 K (calculated from the melting point). Under the action of ultrasonic vibrations, the polymer molecules acquire in the melt a directional position, which is maintained after the start of mass caking (section 2-3 before it begins to solidify. At this interval, starting from T. 3, the monolithization process takes place, i.e. the formation of monolithic structure that binds metal parts of the product. After cooling, which can go both naturally and forcibly, the polymer part at 10-20 K carries out its volumetric deformation - Vol.4, as a result of which the polymer acquires not circumferential form.

Upon completion, the monolithization, deformation and cooling of the polymer part of the finished product is removed from the base 3 and the lining 4 and the sleeve 5 are removed.

The possibilities of obtaining metal-polymer products using the proposed method are investigated depending on the frequency of ultrasound. At the installation used, the dependence of the heating time of the polymer powder on the ultrasound frequency is obtained. In the frequency range 15–18 kHz, a significant increase in the monolitization time is observed along with deterioration of the properties of the products; at frequencies above 25 kHz, the time is almost constant, but the temperature field is heterogeneous over the volume of the polymer part. This leads either to overheating of the polymer, or to its insufficient melting, which impairs the physical and mechanical properties of the polymer part of the product.

The strength properties of the products obtained by the proposed method, in comparison with the same products obtained by injection molding, are given in table. 2

Conduct experimental studies of energy consumption (for the consumption of thermal energy) to obtain a single billet. Thus, to obtain a metal-polymer gear product (Fig. 4), the proposed method requires 5.6 W h (diameter of the polymer part is 12 mm, height 15 mm, UHMWPE material), while by a known method it is about 50 W h. This is due to the fact that, in the known method, it is required to actually double the heating of the polymer part, and re-heating the polymer is coupled with additional heat consumption for heating the mold and the metal part of the product.

The limiting values of the dispersion of the powder 20 and 400 microns are due to the fact that

larger particles no longer provide sufficient acoustic contact. This leads to a rapid attenuation of ultrasound in the mass of the polymer, which confirms 5 with the data given in table. 3. The monolitization of such a material and the orientation of its molecules will be weakly expressed, which causes low physical and mechanical properties of the product as a whole.

0 The optimal amplitude values of the ultrasonic vibrations are in the range of 10-60 µm. The lower limit (10 µm) cannot be reduced, since in this case there is no effective supply

5 energy to a powdered polymer. The tests carried out with blanks made from UHMWPE (cylinder 0-10 mm, h 15 mm) showed the absence of visual signs of monolithization of the latter at any time by the action of ultrasonic vibrations with the said amplitude. The upper limit of the amplitude of oscillations (60 μm) is limited to the beginning of the process of destruction of the polymer. Tested with

The above 5 blanks showed that the surface layer of the polymer in contact with the waveguide is subjected to destruction. The control of the onset of destruction is carried out visually by the appearance of volatile

0 polymer decomposition components.

The strength properties of blanks obtained by various methods are given in table. 4 (with a draw ratio of Ra 7).

Thus, the use of the proposed method will allow to increase the strength properties of metal polymer gears (to increase the torque transmitted by them by about 20%) and to reduce the energy consumption for their manufacture.

Claims (3)

Claim 1. Method of manufacturing products, including the formation by monolitization of the floor 5 of the immersion part from thermoplastic powder when exposed to ultrasonic vibrations until the temperature exceeds the melting point of the thermoplastic by no more than 10 K, followed by cooling and volumetric deformation of the polymer parts, characterized in that, in order to improve the physicomechanical properties of metal-polymer products, for example, high loaded gears, while simultaneously reducing energy consumption, tvie ultrasonic wobbles is carried out with an amplitude of 10-60 microns, the volumetric deformation is produced during cooling into the polymer part. 2. A method according to claim 1, characterized in that the cooling process of the polymer part is limited to a temperature of 10-20 K lower than the melting temperature of the thermoplastic. 3. The method according to claims 1 and 2, characterized in that the thermoplastic powder with a particle size of 20-400 microns is used as the starting material for the polymer part of the product. Note. The frequency of 22 kHz, the dispersion of the powder is 20-400 microns. Note. The content of particles with a given diameter in the test powder is more than 70%. The solidity of the material is determined by color, transparency, and other visually controlled characteristics. The frequency of ultrasonic vibrations 22 kHz. Table 4 Table 1 table 2 10Table 3 03 with so with "A-g- "about 3 ten “About 3 FIG. CTP T ocher wednesday B heat LOXJI. B min