摘要
通常情況下，術(shù)語(yǔ)“高速鉆床”就是指具有較高切削速率的鉆床。高速鉆床(HSDM)也是指具有非?？斓暮驼_的點(diǎn)到點(diǎn)運(yùn)動(dòng)的鉆床。新的HSDM是由帶有兩個(gè)直線電動(dòng)機(jī)的平面并聯(lián)機(jī)構(gòu)組成。本文主要就是對(duì)并聯(lián)機(jī)器(PKM)的動(dòng)力學(xué)分析。運(yùn)動(dòng)合成是為了介紹一種新方法，它能夠完善鉆孔操作和點(diǎn)到點(diǎn)定位的準(zhǔn)確性。動(dòng)態(tài)合成旨在減少因使用彈簧機(jī)械時(shí)PKM的輸入功率。
關(guān)鍵詞: 并聯(lián)運(yùn)動(dòng)機(jī)床; 高速鉆床; 動(dòng)力學(xué)的合成
1.介紹
在最近的幾年里，研究所和工業(yè)協(xié)會(huì)介紹了各式各樣的PKM。其中大部分（但不是所有）,以眾所周知的斯圖爾特月臺(tái)[1]為基礎(chǔ)結(jié)構(gòu)。這一做法的好處是高公稱的負(fù)載重量比，良好的位置精度和結(jié)構(gòu)剛性[2]。斯圖爾特式PKM的主要缺點(diǎn)是相對(duì)小的工作空間和相對(duì)慢的操作速度 [3,4]。機(jī)床刀具的工作空間是指刀尖能夠移動(dòng)和切削材料所需要的容積。平面的斯圖爾特月臺(tái)的設(shè)計(jì)在[5]中被提到，像是對(duì)無(wú)CNC機(jī)器作翻新改進(jìn)的方法需要塑料的鑄模機(jī)制一樣。PKM[5]的設(shè)計(jì)允許可以調(diào)整幾何學(xué)已經(jīng)被規(guī)定了的最佳的再配置的任何路徑。 一般的，改變一根或較多連桿的長(zhǎng)度是以PKM受約束的順序來(lái)做幾何學(xué)的調(diào)整。
Abstract
Typically, the term‘‘high speed drilling’’ is related to spindle capability of high cutting speeds. The suggested high speed drilling machine (HSDM) extends this term to include very fast and accurate point-to-point motions. The new HSDM is composed of a planar parallel mechanism with two linear motors as the inputs. The paper is focused on the kinematic and dynamic synthesis of this parallel kinematic machine (PKM). The kinematic synthesis introduces a new methodology of input motion planning for ideal drilling operation and accurate point-to-point positioning. The dynamic synthesis aims at reducing the input power of the PKM using a spring element.
Keywords: Parallel kinematic machine; High speed drilling; Kinematic and dynamic synthesis
1. Introduction
During the recent years, a large variety of PKMs were introduced by research institutes and by industries. Most, but not all, of these machines were based on the well-known Stewart platform [1] configuration. The advantages of these parallel structures are high nominal load to weight ratio, good positional accuracy and a rigid structure [2]. The main disadvantages of Stewart type PKMs are the small workspace relative to the overall size of the machine and relatively slow operation speed [3,4]. Workspace of a machine tool is defined as the volume where the tip of the tool can move and cut material. The design of a planar Stewart platform was mentioned in [5] as an affordable way of retrofitting non-CNC machines required for plastic moulds machining. The design of the PKM [5] allowed adjustable geometry that could have been optimally reconfigured for any prescribed path. Typically, changing the length of one or more links in a controlled sequence does the adjustment of PKM geometry.