Rakise projekteerimine võidusõiduautode käänmike freesimiseks

Lõputöö käigus projekteeriti ning valmistati, Toyota GT68 võidusõiduauto, käänmiku freesimiseks spetsiaalne töötlusrakis. Rakise projekteerimisel võeti arvesse ettevõttes olemasolevaid seadmeid, kinnitusmeetodeid ja abivahendeid. Samuti arvestati käänmiku keeviskonstruktsiooni eripära ning sellest tulenevaid kitsaskohti. Rakise projekteerimisel järgiti ka ettevõtte seatud nõudeid. Läbi mitmete versioonide leiti kõige optimaalsem lahendus. Rakise projekteerimine ning valmistamistehnoloogia viidi läbi kasutades ettevõtte masinaparki. Valmistamisel arvestati ettevõttes olevate materjalidega ja nende töötlemise võimalustega. Projekteerimisfaasis määrati rakistusele nii standard- ja mittestandard kinnitus- ja paigalduselemendid. Paigaldustäpsuse, tolerantside tagamise ja jäikuse parandamiseks arvutati välja maksimaalsed tekkivad lõikejõud, klambrite kinnitusjõud ning koostati sõrmede täpsusarvutused. Majanduslikus osas keskenduti rakise omahinna leidmisele. Omahinna leidmiseks koostati tabelid - projekteerimise kulust, töötluskulust, materjalikulust ja ostutoodetest. Lisaks omahinnale koostati ka tasuvusarvutus. Rakise omahind oli 2447 eurot ja arvestades 8-protsendilist aastast kasvu, oli tasuvusajaks 2,2 aastat. Rakisele seatud tingimused ja eesmärk, projekteerida piisavalt jäik, mugav, lihtsasti seadistatav ja kiire tükivahetusega rakis, sai täidetud. Lisaks leiti lahendusi detaili kiiremaks tootmiseks tulevikus, paigaldades neli käänmikku freespingi lauale.

During the thesis, the design and fabrication of the Toyota GT68 racing car's knuckle milling fixture were carried out. The fixture design considered the company's existing equipment, fastening methods, and auxiliary tools. The design also considered the welding construction of the knuckle and the resulting critical points. Additionally, the fixture design adhered to the company's requirements. Through various versions, the most optimal solution was found. The design and manufacturing technology of the fixture were executed using the company's machinery. The fabrication took into account the available materials in the company and their processability. During the design phase, both standard and non-standard fastening and installation elements were determined for the fixture. To ensure precise installation, maintain desired tolerances, and enhance stiffness, calculations were performed for maximum cutting forces, clamp fastening forces, and accuracy. In terms of economics, the focus was on determining the fixture's cost price. Tables were created to calculate the design cost, machining cost, material cost, and purchased products. In addition to the cost price, a profitability calculation was also conducted. The cost price of the fixture amounted to 2447 euros, and considering an annual growth rate of 8 percent, the payback period was determined to be 2.2 years. The conditions and goals set for the fixture, namely to design a sufficiently rigid, comfortable, fast adjustable fixture, were fulfilled. Additionally, solutions were found to expedite the future production of the component through the installation of four knuckles on the milling machine table.