Coolant nozzle

#(1) Field of the Invention

#The invention relates to machining. More particularly, the invention relates to superabrasive machining of metal alloy articles.

#(2) Description of the Related Art

#FIG. 1 is a view of a nozzle according to principles of the invention.

#FIG. 2 is a vertical sectional view of the nozzle of FIG. 1 taken along line 1-1.

#FIG. 3 is a front x-ray view of the nozzle of FIG. 1.

#Like reference numbers and designations in the various drawings indicate like elements.

#FIG. 1 shows a nozzle 20 for lubricating/cooling a bit 22 held by a spindle 24 of a machine tool 25 (FIG. 2). An exemplary bit is a superabrasive quill. The bit has a shaft with a distal doubly convex (e.g., hemispherical) head 26 and distal shaft portion 28 which have an abrasive coating or embedded abrasive particles (e.g., plated cubic boron nitride or diamond grit). The bit has an intermediate enlarged portion 30 having flats (not shown) for gripping by a tool and a proximal portion (not shown) for mounting the bit to the spindle. The nozzle has a front surface 40 (FIG. 2) and a back surface 42. The back surface may include features (e.g., a channel 44) for mating to complementary features of the machine tool front to register the nozzle in an operative position in precise alignment with the machine tool. Securing means may be provided such as mounting apertures 46 (FIG. 1) for receiving studs protruding from the machine tool or fasteners extending into the machine tool to removably secure the nozzle registered in the operative position. Alternatively, a clamping mechanism may be used in conjunction with an automated tool changer. In the operative position the nozzle has an aperture 50 encircling a central longitudinal axis 500 of the spindle and bit. The aperture is, in principal part, defined by an internal surface 52 in close spaced part relation to the bit intermediate portion 30 (e.g., with a radial clearance of up to about 1 cm, more narrowly 5 mm). In the exemplary embodiment, a forward portion 56 of the spindle is received within a recess 58 in the nozzle aft surface. In the exemplary embodiment, the recess 58 surrounds the spindle forward portion with an appropriate radial clearance and is connected via passageways 60 (FIG. 1) to the nozzle lateral periphery. The passageways 60 permit passage of cooling air to reach the spindle.

#A principal function of the nozzle is to introduce a cooling and/or lubricating fluid to the bit. At its lower end, the nozzle has with a fluid inlet 62 which feeds fluid to a trunk 64 of a fluid passageway network the respective portions of which are defined by associated internal surface portions of the nozzle. The trunk 64 feeds an exemplary three branches 66, 68, and 70 (FIG. 3). The branches feed a plenum 72 encircling the axis 500. The branch outlets to the plenum are spaced at approximately even 120° intervals so as to provide even introduction of fluid to the plenum. A circular array of outlet passageways 74 (FIG. 2) extend from the plenum to a nozzle boss 76 on the front surface 40 encircling the aperture 50 (FIG. 4). In the illustrated embodiment, each outlet passageway extends to an outlet 80 on an outlet boss 82 protruding from a slightly inwardly-facing frustoconical rim surface 84 of the nozzle boss 76. The outlet and a surrounding rim 86 are oriented facing forward and inward toward the axis 500. A terminal portion 90 of each outlet passageway is downstream divergent and elongate along a plane along the axis 500 so as to have a length L in such plane and a width W transverse thereto. Such a configuration produces a spray 100 that fans out at an approximate angle θ1 in such plane to impact the bit along the intermediate portion 30 with a centerline 101 at an acute angle θ2 to the axis 500. The angles θ1 and θ2 are chosen so that the sprays provide essentially total coverage along the length of the abrasive portion of the quill. The large number of outlets provides a highly redundant coverage around the circumference of the quill so that, during the machining operation, the effects of the workpiece blocking one or more of the sprays are minimized.