Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B5/00—Turning-machines or devices specially adapted for particular work; Accessories specially adapted therefor
  • B23B5/28—Turning-machines or devices specially adapted for particular work; Accessories specially adapted therefor for turning wheels or wheel sets or cranks thereon, i.e. wheel lathes

Definitions

• This invention concerns the Portal-type Wheel Lathe for machining of wheels and brake discs of wheelset dismantled from the vehicle and clamped in two centers of quills ovably located on portal tailstocks and driven by frictional rollers put on the wheel tread of wheelset.
• the machine tools of this kind are known for example from patent specifications: DE No 3809250 and PL 159898 in which two tailstocks have movable quills with centers for wheelset clamping. These machine tools also have two saddles, movable in horizontal, with tool tips movable crosswise (radially) to the wheelset axle and two frictional drives for wheels, each consisting of four rollers, diametrically set in pairs opposite to each other and pressed against the wheels.
• Such a solution enables transmission of considerable (large) circumferential forces on the wheelset wheels at reprofilying of profile shapes in continuous way with one pass.
• the frictional rollers described often cause overlap of chips on the machined wheel tread and as a result of it, inadmissible machining defects appear.
• the other turning lathe known from the DE 3931747 specification has: a lever system of bottom supporting rollers which serve the same as lifting jack of each wheel adequately synchronized by electronic control system; a lever system of one or two top rollers constituting a main frictional drive for wheelset and the levers are suspended in coupling units located on both ends on the machine and are equipped, near the rollers, with joints and cylinders in order to smoothly press the rollers against the irregularity of wheel surface; two axially movable quills with fixed centers for centering and clamping of the wheelset.
• the system of supporting rollers constitutes a console displacing upwards and downwards by a unit of two helical gears driven by separate motors.
• the second console with at least one pressure roller is located opposite to the bottom console with a possibility of simultaneous displacement against wheelset upwards and downwards with helical gear and hydraulic cylinder.
• Mutual travels of both lever consoles with bottom and upper rollers are synchronized.
• Both bottom and upper rollers, fixed on the console levers, have follow-up hinged radial travels forced by irregularit es of contact surface of roller with wheelset wheels.
• Another variant of this invention known from the EP 0528058 description is the method of carrying out the machining in which the wheelset, clamped in quill centers, is driven by at least one frictional roller of console lever, pressed with determined force against the flange of at least one wheel of the wheelset.
• the roller under the influence of pressing force, constantly touches the changing shape of the flange top, while the cutting tool represents the profile shape and is led continuously from outer edge of wheel tread to the flange top and parallel to wheelset axle exit of the tools.
• the flange is machined starting from inner face surface to the top of the flange.
• wheel circumferential surface means wheel tread, flange surface and surfaces between these above surfaces.
• machine from description DE 3931747 can be used, exchanging the frictional rollers applied for straight rollers or with circumferential groove or semi-groove, driving the wheels against their flange.
• Another variant of this solution provides, at first, the initial machining of the area of contact between the frictional roller and wheel what causes a smooth contact surface enabling the achievement of higher friction force and as a result, larger cross-section of the cut chip. It is also possible to eliminate constantly changing radial forces originating from hysteresis of external forces system.
• the topic of the invention is elaboration of such design of the machine in which friction drive rollers, adhering by their external shape to the wheel tread, will not enable the chips, causing inadmissible surface defects of the machined profile, to get into contact area and produce the sufficient torque for economical profile cutting with forces minimizing the deformation of the wheelset and load of means which clamp and center the wheel set .
• each clamping-driving unit includes body and hinged (upwards and downwards) top and bottom double-arm levers fixed to the body by shafts.
• the arms of bottom and top levers which are more away from the machine longitudinal axis, are coupled with the body by means of cylinders with compensators of pressing forces of frictional rollers.
• a pair of fictional rollers lays diametrically opposite to each other and is clamped on shaft mounted on bearings in holders, fixed on the arms of levers which are closer to the longitudinal axis.
• Each roller is provided with individual drive and their forces of pressing against wheel are different with regard to value and changing in function towards changing active value of cutting force and lay in different planes crossing the machine longitudinal axis and deflected from vertical plane of ram movement (with tools) and also crossing the longitudinal axis.
• the machine includes also the floor, rotarly fixed to the consoles and placed under the portal frame and wheelset.
• the floor includes two segments connected with a joint. One segment is equipped with the lifting jack and cylinder of which the second end is fixed to the foundation in order to lift the floor to the track rails level and then only to the segment with lifting jack, and this segment also performs the function of wheelset ejector beyond the machine onto the track rails.
• the plane crossing the axes of swivel of levers on the shafts towards the lever rotation, is perpendicular to the plane formed by the symmetry axis of guideways of this unit and machine longitudinal axis, and each bottom drive roller, located asymmetrically in relation to the top drive roller, is situated in the area protected against chips and created by the view of cross-section surface of the wheel and cover, for example rotary one, over the additional roller.
• the movement of the lifting jack within cycle of lifting and centering the wheelset axis in center axis, is coupled electronically with the measuring head t ravel .
• fig.1 shows the r.h half of the machine from front view
• fig.2 the machine from fig.1 in partial cross-section I-I and side view
• fig.3 the machine from fig.1 in view from above
• fig.5 schematically the system of external forces acting on the wheel
• fig.6 polygon of forces from fig.5.
• the machine shown on fig.1-3 includes body (6) in the form of portal, which is created by two consoles (7) set on the foundation and connected with middle part (8).
• Each console has a tailstock body (27) fixed to its front vertical surface and equipped with known means (extendable quills (28) with mounted centers (29)) for clamping and centering of wheelset (1) in the machine axis (17).
• the middle part(8) of the portal body (6) has known guideways (9), fixed to the face and in the front, for saddles (9'), located movably along the axis (17), which are equipped with slides (11) and (12), located movably in the vertical plane crossing the axis (17), and a measuring head (not shown).
• the horizontal travel of the saddle (9') is carried out by means of a drive (13) of rotary nut, mounted on bearings on permanent screw (10) which is fixed to the part (8) of the body (6).
• individual radial movements of slides (11, 12) are ensured by their drives 14, including helical ball transmissions, toothed-belt transmissions and AC motors with frequency adjustment.
• the slide (11 ), provided with compound tools of cassette type, is designed to machine side surfaces of brake discs, mounted on the wheelset axle (2).
• the double-side tool (16) is displaced from the tool (15) longitudinally and crosswise to the madhine axis (17).
• the tailstock (27) is equipped with guideways (30), inclined towards the vertical plane crossing axis (17), for pressing-driving unit (31) of each wheel (2), which is set on them movably along axis (17).
• the unit (31) of each wheel (2) includes body (31'), hinged (upwards and downwards) pairs of top (32, 32') and bottom (33, 33') double-arm levers, mounted on its shafts (34).
• the arms (32', 33') of the levers which are more away from axis (17), are coupled with cylinders (37) through compensator (accumulator), for example spring type, of pressing force, responding on the radial irregularities of tread (3) of wheels (2) with the body (31') situated opposite.
• compensator for example spring type, of pressing force, responding on the radial irregularities of tread (3) of wheels (2) with the body (31') situated opposite.
• rollers (35, 35') lay diametrically opposite each other and are pressed by cylinders (37) against the tread (3) of the wheels (2) with di fferent-in-value forces (40, 41) laying in different planes (38, 39) crossing the axis (17) and inclined in relation to the vertical plane of movement of slides (11), (12) in axis (17).
• Friction forces (42, 43) driving each wheel (2) are proportional to the pressing forces (40, 41) of rollers (35, 35') against the tread (3) of the wheels (2).
• Shaft drive (34) of each roller (35, 35') includes, by example, double-run planetary gear and asynchronous motor of infinitely variable speeds.
• Different-in-value forces (40, 41) of rollers (35, 35') pressing against the tread (3) of wheel (2) are subject to changes in the cutting process in function of changing values of circumferential cutting force (44).
• the changes are controlled with proportional valves of hydraulic system of cylinders (37).
• the plane generated by the axes of suspension of levers (32, 32', 33, 33') is perpendicular to the plane generated by the symmetry axis of guideways (30) and machine axis (17) what causes that polygon of external forces (40, 42, 41, 43, 44, 45) (fig.6) acting on wheel (2) produces resultant force (48) acting on each rotary center (29), which is lower that the weight (46) of the wheelset (1).
• Bottom roller (35') is located in the swarf-protcrank area, created by the view of cross-section surface of the wheel (2) and cover, for example rotary one, over the wiping roller (47) from the side of chip disposal.
• Top roller (35) is located before the cutting tool from the above, forming passive, wedge-shaped surface in relation to the rotating wheel of the wheelset (1).
• the floor segment (21') is equipped with lifting jack (23)for the wheelset (1) and cylinder (24), fixed in self-aligning way to the foundation and floor in order to turn aside the floor (21 , 21 ' ) in relation to its rotary axis (22) from the position close to the vertical shown on fig.2 with full lines to the position shown with broken fine lines in such a way that floor segments (21 , 21') are the extension of track rails (25). Segments (21 , 21') are connected with a joint (26) in order to get small inclination of top planes of both segments in relation one to another.
• Floor segment (21 ') with the lifting jack (23) for wheelset (1) plays also a role : of wheelset ejector, causing automatic rolling out of wheelset onto the track rails (25) after the profile machining cycle is completed, when instantaneously the cylinder (24) acts, turning upwards the segment (21') in relation to the horizontal floor segment (21).
• the movement of lifting jack (23), within the cycle of lifting and centering the wheelset (1), towards the axis of centers (29) is electronically coupled with the radial travel of measuring head (not shown on the drawing).
• Floor segments (21, 21') in the upper position, concealed under the middle part (8), constitute a chute for chips, produced during machining.
• Motors of drive (13) of ball nuts of saddles (9), motors of drives (14) of slides (11 , 12), motors of drives (36) of each driving frictional roller (35, 35') and cylinder of lifting jack (23) and cylinders (24, 37) are connected respectively with cables to the CNC system of machine control equipped with central panel (not shown on the drawing). CNC system is supplied from the mains (not shown on the drawing). LI ST OF DENOMI NAT I ONS
• Double- ⁇ i de tool

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Turning (AREA)

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Publications (1)

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• 1995
  • 1995-01-17 PL PL95306883A patent/PL175431B1/pl unknown
  • 1995-05-04 WO PCT/PL1995/000007 patent/WO1996022171A1/en not_active Application Discontinuation
  • 1995-05-04 CN CN95197364A patent/CN1059620C/zh not_active Expired - Fee Related
  • 1995-05-04 EP EP95916869A patent/EP0804311A1/en not_active Withdrawn
  • 1995-05-04 RU RU96121353A patent/RU2132255C1/ru active

Non-Patent Citations (1)

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