\nTo \u017ee doch\u00e1dza ku ve\u013ek\u00fdm za\u0165a\u017eeniam iba v ur\u010dit\u00fdch oblastiach ste si asi v\u0161imli na pou\u017eit\u00fdch piestoch. Zvy\u010dajne s\u00fa to vydrat\u00e9\/vyle\u0161ten\u00e9 plochy na sten\u00e1ch. To s\u00fa pr\u00e1ve miesta, kde doch\u00e1dza ku najv\u00e4\u010d\u0161iemu a naj\u010dastej\u0161iemu kontaktu medzi piestom a valcom motora.
\n
![\"4-Pistons2\"](\"http:\/\/mixmotor.eu\/wp-content\/uploads\/2013\/12\/4-Pistons2.jpg\")
<\/a><\/p>\nJE uk\u00e1zalo graf bo\u010dn\u00fdch s\u00edl na piestne steny (priemer piesta, alebo aj inak povedan\u00e9 v\u0155tanie bolo 104,14mm). V\u00fdrazne vidno rozdiel medzi minoritnou (malou) a hlavnou hodnotou p\u00f4sobiacich s\u00edl. Hlavn\u00e9 za\u0165a\u017eenie dosahuje hodnotu takmer 12.000N (cca 1200kg) a mal\u00e9 za\u0165a\u017eenie 3.000N (cca 300kg). Jasne vidno, pre\u010do je v\u00fdhodnej\u0161\u00ed asymetrick\u00fd piest – minim\u00e1lne zlo\u017eky s\u00edl s\u00fa “stiahnut\u00e9” tvarom piesta bez probl\u00e9mov a najv\u00e4\u010d\u0161ie zlo\u017eky s\u00fa \u010falej pren\u00e1\u0161an\u00e9 pomocou pred\u013a\u017eenej steny.<\/p>\n
<\/p>\n
Dodato\u010dn\u00e9 obr\u00e1zky z anal\u00fdzy MKP (met\u00f3da kone\u010dn\u00fdch prvkov) vyobrazuje nap\u00e4tia p\u00f4sobiace na a v pieste. Na bo\u010dn\u00fdch sten\u00e1ch vidno len minim\u00e1lne rozdiely. Nap\u00e4tie na dlh\u0161ej strane piesta dosahuje miestami 125MPa, pri\u010dom na kr\u00e1tkej strane je to pribli\u017ene hodnota 100MPa. Kr\u00e1sne vidno vyu\u017eitie po\u010d\u00edta\u010dovej techniky v praxi, ktor\u00e1 pom\u00e1ha pri rie\u0161en\u00ed tvarov piestov. Pri tom ani jedna hodnota na vidite\u013en\u00fdch miestach piesta nedosiahla maximum (\u010derven\u00fa farbu), \u010do predstavuje 300MPa.<\/p>\n
<\/p>\n
V\u00fdhody asymetrick\u00fdch piestov<\/b><\/p>\n
Ni\u017e\u0161ia hmotnos\u0165, ni\u017e\u0161ie trenie bo\u010dn\u00fdch stien, prakticky vyu\u017eit\u00e9 rozmery bo\u010dn\u00fdch stien, hrub\u0161ia hlava piesta, krat\u0161\u00ed piestny \u010dap (\u010do zn\u00ed\u017eilo v tomto pr\u00edpade jeho hmotnos\u0165 o 10g).
\nDokonca bola posunut\u00e1 diera pre piestny \u010dap o 5,08mm (na tomto konkr\u00e9tnom pieste s priemerom 104,14mm) ku \u0161ir\u0161ej a krat\u0161ej stene piesta kv\u00f4li vyrovnaniu statickej a dynamickej rovnov\u00e1hy. Doteraz sme poznali v\u017edy iba vystreden\u00e9 diery a dlh\u00e9 piestne \u010dapy. Zamedzovalo to h\u00e1dzaniu piesta vo valci a z\u00e1rove\u0148 toto kon\u0161truk\u010dn\u00e9 vyhotovenie zni\u017eovalo hluk.<\/p>\n
<\/p>\n
Koruna piesta bola vystu\u017een\u00e1 na potrebn\u00fdch miestach tak, aby preniesla vysok\u00e9 nap\u00e4tia, ktor\u00e9 v tomto pr\u00edpade dosiahli \u010d\u00edslo a\u017e 300MPa. O tom, pre\u010do m\u00e1 piest vybratia na hornej spa\u013eovacej strane u\u017e ale niekedy inokedy. Sledujte n\u00e1s a udr\u017e\u00edme v\u00e1s v slede inform\u00e1cii.<\/p>\n
<\/p>\n
<\/p>\n
*Predstavovan\u00e9 asymetrick\u00e9 piesty s\u00fa dostupn\u00e9 pre motory LS1, LS6, Z06, 5,7l a 6,0l.<\/p>\n
Autor: Vladislav Baniari; Zdroj: Enginelabs.com; Foto: Enginelabs.com, JE Pistons<\/p>\n","protected":false},"excerpt":{"rendered":"
Merania bo\u010dn\u00fdch za\u0165a\u017een\u00ed Ke\u010f kon\u0161trukt\u00e9ri navrhuj\u00fa nov\u00fd piest, musia mnoho hodn\u00f4t z\u00edska\u0165 aj priamym meran\u00edm r\u00f4znych za\u0165a\u017een\u00ed ktor\u00e9 vznikaj\u00fa pri pohybe piesta vo valci. Vykon\u00e1vaj\u00fa to pomocou r\u00f4znych merac\u00edch senzorov, ktor\u00e9 lepia\/upev\u0148uj\u00fa na vyle\u0161ten\u00e9 plochy valca a steny piesta. To \u017ee doch\u00e1dza ku ve\u013ek\u00fdm za\u0165a\u017eeniam iba v ur\u010dit\u00fdch oblastiach ste si asi v\u0161imli na pou\u017eit\u00fdch […]<\/p>\n","protected":false},"author":1,"featured_media":5191,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[4],"tags":[22,500],"class_list":["post-5232","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dokumentarne","tag-motor","tag-piest"],"translation":{"provider":"WPGlobus","version":"3.0.0","language":"de","enabled_languages":["sk","en","de"],"languages":{"sk":{"title":true,"content":true,"excerpt":false},"en":{"title":false,"content":false,"excerpt":false},"de":{"title":false,"content":false,"excerpt":false}}},"_links":{"self":[{"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/posts\/5232","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/comments?post=5232"}],"version-history":[{"count":3,"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/posts\/5232\/revisions"}],"predecessor-version":[{"id":5243,"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/posts\/5232\/revisions\/5243"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/media\/5191"}],"wp:attachment":[{"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/media?parent=5232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/categories?post=5232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mixmotor.eu\/de\/wp-json\/wp\/v2\/tags?post=5232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}