Summary: ? The treatment that cylinder of?5 series diesel engine covers atomizer hole is exemple, analysed dimensional double inclined hole to machine the treatment process that uses clamping apparatus system, derivation the design of its dimension public errand is formulary. 1 foreword in the production process that waits in machine tool, clamping apparatus, often need to machine a few inclined hole that have accurate space place, double inclined hole or cant. As a result of the difficulty on the technology, cannot be measured directly when treatment and control its dimension public errand, because this wants a these need,can be measured directly on pilot dimension and craft of tolerancepublic errand translate into or measure of direct pilot technology and public errand. Pass the control of pair of technology measure after changing, public errand, indirect ground makes sure workpiece designs the requirement of dimension and its public errand. The treatment that the article covers atomizer hole with cylinder of 75 series diesel engine is exemple, the design that clamping apparatus system uses when double to the space inclined hole is machined and treatment process undertook theoretical analysis, with period the difficulty in solving this kind of workpiece to place specific and actual production, design. Pursue 1 workpiece diagram pursues 2 work are three-dimensional diagram pursues 3 treatment use sketch of clamping apparatus body the design work of machining error and clamping apparatus body process form of 2 clamping apparatus the substantial that body of process clamping apparatus is treatment of workpiece of double inclined hole and it is difficult treatment, closely related the computation that places specific machining error and its process. Workpiece diagram sees a picture 1, double inclined hole of the 3-Ød1 on its machines aperture to wait for. To the double inclined hole of this kind of type, commonly used method is with one side two aperture decide a method (the 2-Ød2 aperture on workpiece underside Q and its face) undertake machining, consequently its place specific treatment basically is the treatment that fixed position surface and fixed position cylinder sell aperture and lozenge to sell aperture. If the graph is shown 2 times, it is the axes abstraction of double inclined hole on workpiece work is three-dimensional one of diagram linear MN. Machine a requirement according to drilling machine, need to adjust linear MN for plumb line, because this workpiece needs to rotate through two: The planar edge that is in linear MN above all is anticlockwise rotate A horn; Rotate workpiece again next B horn. Accordingly, on the cant that processes clamping apparatus form should assure to workpiece is put in one dip to be B and two fixed position sell connect line and horizontal into A horn (3) seeing a picture. Body of treatment clamping apparatus uses all-purpose tool mill or CNC Milling normally. With be on mill of common and all-purpose tool treatment is exemple: Machine the underside P that gives clamping apparatus put oneself in another's position above all, assure its flatness, retroflexion its the planar Q(that the treatment after horn of B ± B gives to be used for work location assures its flatness) ; Machine the columnar A that sell aperture in Q face next, machine aperture B for the foundation with this, make sure B of aperture A, aperture and workpiece locate the verticality of face Q asks at the same time. To facilitate aperture B machines the specification of the problem, building a XOY coordinate with Q face coincide is, its X axis and horizontal CD parallel (3) seeing a picture. XB of shift of axis of workpiece edge X, along Y axis mobile YB gets aperture B fastens medium coordinate in XOY coordinate (XB, YB) . The dimension public errand of clamping apparatus body is in the treatment process of clamping apparatus body, basically should assure XB of ± of B of ± of technology measure B, XB and YB ± YB. The dimension of clamping apparatus body can use strict mathematical method namely analytic law has design, consideration. Analytic law is divided commonly for extreme value law (apply to sheet the treatment with small lot or less number of dimension chain link) with probability law (apply to have enough lot or the treatment) with more number of dimension chain link, count in view of link of this chain of dimension of clamping apparatus body not much, reason uses extreme value law to have consideration. The sells aperture center A in order to place a fixed position on body to be origin coordinate that the graph builds the foundation 3 times is, have group of Cheng of the other side of {LAB=(XB2+YB2)½a=arctg(YB/XB)(1) of basic equation group as follows (1) is begged slant guide, increase the treatment demand that opposes corner B and the design that consider clamping apparatus, get following equation groups (2) {LABXB(YB/LAB)+YB(XB/LAB) ≤ (1/3)LABaXB(YB/LAB2)+YB(XB/LAB2 ≤ (1/3)ab ≤ (in 1/3)b(2) type: XB, YB -- the B of the machining error that is axis of X of dimension XB, YB edge, Y respectively -- the LAB of the machining error of face of P of clamping apparatus body and Q face included angle -- the A of the machining error that center of aperture of on Q of face of fixed position of clamping apparatus body two fixed position is apart from. 3 application example concerns workpiece dimension and LAB=300 ± of ± of tolerancepublic errand LAB 0. 03, ± of ° of B=60 of B ± 30, 30(of ± of ° of A ± A=15 sets XB=YB) generation to join equation group (in 2) , can get {YB=YB ≤ ± 0.
00797XB=YB ≤ ± 0.
7125b ≤ 10(3) machines precision to be IT6 ～ IT8 as a result of the economy of finish machining of all-purpose tool mill, should machine dimension XB=300 when × Cos15 ° , its corresponding dimension public errand is 0.
032 ～ 0.
081, be more than 2XB=0.
01594, afore-mentioned computation show reason as a result, when machining double inclined hole, with all-purpose tool mill cannot satisfy treatment precision requirement. Because this is when body of treatment clamping apparatus, if do not use CNC Milling, need have the aid of to be not economy to machine a method on all-purpose tool mill (if build gauge block) the treatment precision that will assure dimension XB, YB and B angle, in order to satisfy the production precision requirement of clamping apparatus. 4 epilogue rise ceaselessly as what the spare parts machines precision, treatment form is increasingly complex, make the mathematical calculation of fixed position error becomes more and more difficult. Author in Jiangxi diesel engine cylinder of 75 series diesel engine builds the plant in the effective treatment of atomizer aperture, it is better to use extreme value method the design that the ground solved double inclined hole to process clamping apparatus form, production difficult problem, got favorable applied result, the treatment of the inclined hole that has accurate space place to other, double inclined hole or cant also has referenced effect. CNC Milling
CNC Machining