02~ φ 0.
01mm, but error of workpiece axial displacement is bigger, apply to workpiece to locate aperture precision is not mixed under the fine vehicle of IT7 grinding, but cannot wait for the work that has axial dimension precision as end panel of treatment of axial fixed position. The structural dimension of small taper arbor is shown by watch 3-12 place. Have enough stiffness to assure arbor, the long way of arbor compares L/d ＞ 8 when, the cent of tolerancepublic errand limits that should press workpiece fixed position aperture is 2~3 group, every groups design an arbor. Taper of arbor of watch 3-11 high accuracy recommends diameter of aperture of value work location of K of taper of 100>100 of ～ of 8080 of ～ of 7070 of ～ of 5050 of ～ of 2520 of D/mm8 ～ 4, columnar side fixed position is constant beyond the workpiece of fixed position component when columnar face locates beyond workpiece: (one) V form piece graph 3-55 place is shown, v form piece main parameter has: D -- V form piece design arbor diameter, the average size of tool reference plane of D= work location, its axes is fixed position fiducial; α -- V form piece the included angle between two working face has 60 0, 90 0, 120 0 3 kinds, apply with 90 0 the widest; H -- V form piece height; T -- V form piece fixed position height. Namely V form piece fixed position is standard to V the distance of form piece underside; N -- V form piece mouth dimension. V form piece already standardized, the parameter such as H, N all but from national level " machine tool clamping apparatus and component " in check, but T must be calculated. By the graph 3 - 55 knowable: H of ＝ of OC of ＋ of F ＝ H + (OE-CE) because so becomes when α ＝ 90 0, ＋ of T ＝ H 0.
707d - 0.
5N. Graph 3-56 is commonly used V the structure of form piece. Graph 3 -56a is used at tool reference plane of short fixed position of essence of life; Graph 3-56b is used at thick tool reference plane and face of fixed position of a flight of stairs; Graph 3 -56c is used at tool reference plane of longer essence of life and apart datum plane of further two fixed position. V form piece the steel system that does not use integral structure certainly, oil hard backing plate or hard metal can be mounted on cast-iron base board, if pursue,3-56d place is shown. V form piece the branch that has mobile type and stationary. Mobile V form piece application sees graph 5 -57a machines bearing the orientation way of aperture, mobile V form piece outside be being spent freely except limitation, still have clamp effect at the same time. Form piece removes the V in graph 3-57b only position intention, limitative workpiece is spent freely. Secure V the join of form piece and clamping apparatus body, use two fixed position to sell commonly with 2~4 bolt, after fixed position sells aperture to adjust good place when assemble, get together with clamping apparatus body, bore with a reamer, infiltrate fixed position is sold next. V form piece can use at tool reference plane of essence of life already, can use at thick tool reference plane again; Can use at complete round cylinder, also can use at local round cylinder; And have pair of neutral (make the fixed position of workpiece standard always be in V form piece inside the symmetrical plane of two working face) good characteristic, mobile V form piece still can hold clamping unit concurrently. When because this is become,the circle locates beyond workpiece, v form piece it is uses at most fixed position cell. (2) locate 3-58 of the graph that cover is a few kinds of commonly used fixed position to cover, surface of the aperture inside its is fixed position working face. Normally, the round cylinder that fixed position covers and end panel join fixed position, limitative workpiece is spent 5 times freely. When regarding main fixed position as tool reference plane with end panel, should control length, lest pass,locate and make when clamp workpiece generation unallowed is out of shape. Way of this kind of orientation is the central fixed position of clearance fit, reason is stricter also to locating the precision of tool reference plane asks, take journal precision IT7, IT8 normally, exterior surface roughness is worth be less than Ra0.
M of 8 μ . Fixed position covers a construction simple, it is easy to make, but centering precision is not tall, commonly used at small-sized, appearance the fixed position of simple spare parts. (3) if graph 3-59 place is shown,semicircle covers , the semicircle below is covered is fixed position component, the semicircle above covers a clamp action. Way of this kind of orientation basically is used at large shaft kind the part that spare parts and inconvenience place at axial outfit. The precision of fixed position tool reference plane not under IT8~IT9, the smallest internal diameter that semicircle covers should take the maximum of work location tool reference plane. (4) conic the 3-60 that be like a graph is a to turn over a tip commonly usedly, by top 1, bolt 2 and conic cover 3 composition. Workpiece is in with the upright ministry of columnar face conic Kongzhong locates, there is groove in taper hole, rotate in order to drive workpiece. The awl handle part of 1 inserts top put oneself in another's position in aperture of machine tool main shaft, bolt 2 with will deliver torque. CNC Milling