FI101270B - Method and apparatus for centering a tubular piece or attachment thereof - Google Patents

Description

101270

METHOD AND APPARATUS FOR CENTERING OR ATTACHING A TUBULAR BODY

REAR FORMING FOR CENTERING AV ETT RÖRFORMIGT STYCKE ELLER FÄSTNING AV DETTA

The present invention relates to a method and an apparatus for centering or attaching a tubular body according to the preamble of claims 1 and 4 below. The invention is particularly directed to a solution using a mandrel with axially arranged axial support vanes of a tubular body to be treated between the end plates. The mandrel is installed inside the workpiece so that the support wings center the workpiece.

10

It is previously known, e.g. in vertical lathes, in which cylindrical parts are machined, to fasten the workpiece to the lathes with jawed mounting sockets, e.g. a three-jaw chuck with three self-centering mounting jaws. The clamping jaws are turned exactly concentric with respect to the axis of rotation and corresponding to the diameter of the outer surface of the part to be fastened. The clamping jaws are mechanically tightened by means of a helical plate and a gear wheel.

20 In presses used in the assembly of electric motors, in which a jacket or outer shell is pressed onto the stator, a cylindrical body is used as a mandrel to center the stator, which is fitted inside the stator during pressing. A separate and different sized mandrel is then required for each stator of different sizes, which becomes expensive. In addition, changing the mandrel when assembling engines of different sizes takes a relatively large amount of extra time.

101270 2

It is an object of the present invention to provide a mandrel whose diameter is simply adjustable as desired and necessary.

The purpose is thus to provide a mandrel with which simply tubular pieces of different sizes, e.g. cylindrical, square or polygonal in diameter, can be centered or fastened alternately during their handling.

10

The object of the invention is, for example, to provide an adjustable mandrel which can be used when assembling stators of electric motors of different sizes when pressing a jacket or outer shell on top of a stator.

15

It is also an object of the invention to provide a method by which the diameter of a mandrel used for centering or supporting a tubular body to be machined can be simply adjusted to suit.

20

In order to achieve the above objects, the device and method according to the invention are characterized by what is stated in the claims below.

25

The method according to the invention makes it possible to center or fasten tubular bodies of different sizes, such as cylinders, square profile tubes or similar polygonal tubes, using the same adjustable mandrel. The mandrel is preferably cylindrical and concentric with the body to be treated. However, the mandrel may, if necessary, be of the same diameter or almost the same shape as the workpiece.

35 The mandrel is formed by a plurality of wedge-shaped slides or support vanes arranged between the cover and base plates. The outer surfaces of the mandrel parallel to the mandrel axis form the outer circumference of the mandrel and define the diameter of the mandrel. The mandrel can be mounted inside the body to be treated in such a way that the outer surfaces of the support vanes only lightly touch, center or support the inner surfaces of the body to be treated or in such a way that they are firmly pressed against them. If necessary, the support vanes can be pressed onto the inner surfaces so tightly that the mandrel holds the workpiece firmly in the desired position, e.g. during machining.

10

The diameter of the mandrel is adjusted by moving the wedge-shaped slides or support vanes radially inwards or outwards so that they form a mandrel with the desired diameter. The support vanes then slide radially along the end plates, i.e. the cover and base plates. To move the slides or support vanes, a conical central part is used, which is arranged in the central part of the mandrel concentric with the tubular body to be treated as well as the mandrel. The conical central part is displaceable in the direction of the axis of the mandrel and the slides or support vanes are slidably or bearing-connected thereto. In this case, the conical central part, when moving in the axial direction, will also move relative to the support vanes slidably or bearing-connected thereto, the conical shape of the central part forcing the support vanes to move radially inwards or outwards.

In the solution according to the invention, the support vanes can advantageously be used to center the cylindrical body 30 with respect to the desired center point. On the other hand, the solution according to the invention can also be used to center a tube with a square or polygonal diameter. The shape of the tube must, of course, be taken into account when designing the position and shape of the support vanes.

The mandrel according to the invention can also be used only to support a cylindrical or similar body from the inside thereof, whereby the outer surface of the support vanes is pressed against the inner surface of the body to be treated. The friction between the support vanes and the inner surface of the cylindrical part due to compression may even be sufficient to hold the part in place during machining or lifting of the part. In this way, the mandrel according to the invention can be used, for example, as a mandrel for stacking the disc discs of an electric motor stator and for compressing the discs together.

10 In addition, the expansion movement of the support vanes can be considered to be used to shape a thin cylindrical body made of flexible material into a round.

The mandrel according to the invention, on the other hand, can be thought of as being used to support the pipe from outside it or even to compress or pull the pipe together. In this case, support elements are arranged on the outer surface of the pipe, which are connected by rods or similar members passing through the wall of the pipe to the support vanes of the mandrel inside the pipe.

By reducing the diameter of the mandrel, i.e. by moving the support vanes radially inwards, the walls of the pipe can be pulled inwards.

One major advantage of the solution according to the invention is the large stepless expansion of the mandrel 25. The diameter of the mandrel can be easily and quickly increased or decreased steplessly, which makes the tool very flexible. In addition, the diameter of the mandrel according to the invention can be increased very much, easily by more than 10-20%, up to 40%, which makes the 30 mandrels very versatile. For example, in the assembly of electrostats, a jacket can be pressed on three or four different sized stators with one mandrel without changing the mandrel.

The invention will now be described in more detail with reference to the accompanying drawings, in which 101270 5

Figure 1 shows diagrammatically and in partial section a press using a mandrel according to the invention for centering and supporting the stator of an electric motor when pressing the jacket on the stator 5;

Fig. 2 schematically shows a vertical section of a mandrel according to the invention, in particular of its conical central part and of the support wings connected to it in broken lines in the retracted position;

Fig. 3 shows the turn according to Fig. 2, in which the support vanes are partially protruding;

Fig. 4 shows a cross-section along the line AA 'and a partially perspective view of the mandrel of Fig. 2; in addition, the figure shows one support wing with broken lines in the extended position;

Figure 5 is a schematic top view of the support wing; Fig. 6 is a schematic side view of the support vane and

Figure 7 shows a cross-section of the support wing along line BB.

Figure 1 shows an electric motor stator jacket clamp 10 in which a jacket 12 is pressed over an electric motor winding stator 14 using a mandrel 16. A motor end flange 20 and a mandrel 16 preset with respect to diameter and motor are fitted to the press positioning table 18. The mandrel is raised by the actuator 22 to the right level with respect to the motor flange 20 so that the distance between the flange 20 and the stator 14, the so-called e-dimension, the motor becomes correct. The stator is mounted on the mandrel 16 and the jacket 12 is pressed on top of the stator by a press-carriage 24 from above.

Arranged between the end plates 26 and 28 of the mandrel are wedge-shaped support vanes 30 which slide radially along the end plates, the outer surfaces of which form the circumference of the mandrel. A threshold 31 is formed in the lower part of the outer surfaces of the support vanes, which prevents the stator from settling below a certain level 5, whereby the distance between the threshold 31 and the motor flange 20 forms a so-called e-dimensionally.

Snacks 32 are fixedly arranged between the support vanes on the end plates. A control member 10 (not shown) in the central part of the mandrel, i.e. a conical central part, is connected to a vertically movable spacer 34 for adjusting the position of the support vanes 30, i.e. the outer mandrel.

Figure 2 shows a vertical section of a cylindrical mandrel 16. According to the invention, the mandrel comprises two end plates, i.e. a cover plate 26 and a base plate 28, an adjusting member, i.e. a conical central part 38, and a plurality of wedge-shaped slides or support vanes 30 shown in broken lines. The base plate 28 is attached by notches 29 to the mandrel drive member 22 shown in Figure 1, from which the mandrel can be raised or lowered.

The outer surfaces 36 of the wedge-shaped support wings 30 arranged between the base and cover plates 26, 28 form the perimeter of the mandrel, i.e. define the effective diameter of the mandrel. When machining or machining a cylindrical body, the outer surfaces are preferably curved according to the arc of the radius of the body to be treated. The wedge-shaped support wings 30 are arranged between the base and cover plates to slide radially along the plates or possibly to move in a bearing manner. The vanes are partially wedge-shaped in horizontal cross-section and widen towards the perimeter of the mandrel, as shown in Figure 4. All of the sliding surfaces of the mandrel and other wear-prone surfaces, such as the sliding surfaces between the vanes and the end plates, are preferably nitrated.

101270 7

A control portion, i.e. a conical central portion 38, is formed in the central portion of the mandrel, which is formed by the central portion 40 of the cone, radially fixed protrusions 42 and T-shaped rails 44 formed on the outer surface of the protrusions 44. The protrusions 42 are wedge-shaped vertically inwardly. There are as many projections as there are support wings, e.g. 6-10, in the case shown in Figure 1 8. The projections and support wings can, of course, be used more or less as required.

The central portion 40 of the cone is attached at its lower part to an intermediate piece 34 by means of which the conical central portion 38 can be raised or lowered. The spacer 38 is adapted to pass through the opening 46 formed in the base-15 belt. The movement of the spacer can be controlled, for example, with a hydraulic cylinder. Of course, the movement can also be controlled pneumatically or mechanically if desired.

A guide sleeve 48 attached to the center portion 40 of the cone and passing through an opening 47 centrally formed in the cover plate 26 and a stop plate 52 and stop pieces 54 having a diameter greater than the diameter of the opening 47 restrict downward movement of the conical center portion. By adding the stop pieces 54, the conical central part 38 can be supported in a higher position if desired, e.g. in a very precise preset. Fig. 3 shows a mandrel in which the conical central part with the stop pieces 54, 54 'and 54' 'is kept at a higher level of the rack than in Fig. 1. At the same time, in the case shown in Fig. 3, the support vanes 30 have moved radially outwards and thus increased the mandrel diameter.

Figure 4 shows a horizontal cross-section of the mandrel of Figure 2 along the line AA '. The support vanes 30 are shown partly in plan view and partly in section 101270 δ in plane A '. The protrusions 42 and rails 44 of the conical center portion are shown in part in a perspective view. The rails 44 are inclined downwards and outwards towards the second end plate. The support vanes are slidably connected to the rails 44 by oblique grooves 56 formed therein, which are shown only in broken lines in Figs. 2 and 4.

The support vane and the groove formed therein are shown in more detail in Figures 5-7, which show the support vane from above, from the side and in cross section along the line BB. A wide inclined groove 58 is formed in the support vane, which opens towards the center of the mandrel and deepens from the top of the vane towards the lower part. The cross-sectional shape of the groove corresponds to the cross-sectional shape of the protrusion 42.

At the bottom of the groove 58, a smaller groove 56 of T-20 cross-section is formed, the shape of which thus corresponds to the cross-sectional shape of the rail 44 formed in the conical part. The grooves 58 and 56 are formed in the support wing to extend from top to bottom obliquely outward. The groove 56 in the support wing extends at substantially the same angle 25 to the horizontal plane as the rail 44.

The support wing 30 thus consists essentially of two branches or main parts 60 and 62, which are arranged in the mandrel to pass on both sides of the projection 42. The support wing 30 30 is threaded over the protrusions 42 and rails 44 so that the rail 44 locks into the groove 56 and can only slide along the groove.

In very large mandrels, where the own weight of the support vanes and the load applied to them are high, bearing rollers can be used on the sliding surfaces 35, such as the grooves 56, to reduce friction, i.e. to keep the pressurized friction surfaces bearing.

101270 9

Figure 4 shows in broken lines one support vane 30 'pulled outwards from the center of the mandrel. In a mandrel with a unitary conical central part, as shown in Fig. 5, of course, all the support vanes will move outwards at the same time as the middle part is raised.

The small threshold 31 shown in Fig. 2 holds the body 10 to be treated, e.g. the stator of the electric motor, at a certain distance above the positioning table. In this way, for example, space can be left above the motor end ring for the winding coil. In addition, as shown in Figure 2, a small bevel 66 is preferably made in the top of the support wings 30 to help guide the body to be treated, such as the stator, over the mandrel.

The invention is not intended to be limited to the embodiments described above, but is intended to be applicable in as many contexts as possible within the scope of the inventive idea limited by the following claims.

Claims (11)

A method for centering or attaching a tubular piece (14), which method utilizes a mandrel 5 (16), wherein the mandrel end plates (26, 28), so-called. the top and bottom plates, arranged radial support vanes (30) extending in the axial direction of the tubular piece, and the mandrel inserted into the piece to be processed, such that the support wings center or support the piece to be machined, and that the mandrel diameter is adjusted according to the diameter of the piece (14), which in each case is to be machined, by moving the support wings (30) of the mandrel in the radius of the piece to be machined, by means of one in the middle of the mandrel between the end plates (26). (28) provided conical center portion (38) which is movable in the axial direction of the piece to be machined. hence, - to their diameter, different Large tubular pieces (14), which may be cylindrical or to their cross-section 20 square or polygonal pieces, are in turn centered or fixed to the mandrel by support wings (30), the periphery of which has the shape of the inner surface of the a piece to be machined, and that - the support wings are placed on a conically formed conical part (38) formed by radially arranged outriggers, so that each support wing is molded by means of a T-wing or other equivalent spire (56) formed in the support wing at a rail (44) in the mantle of the conical part, to move only along it. 30 Method according to claim 1, characterized in that. that the conical center portion (38), which tapers towards one end plate, the so-called. the top plate (26) and whose periphery is formed by radially arranged wedge-shaped outlets (42), the periphery of which is arranged in the longitudinal direction of the periphery and to its cross-section T-shaped rails (44) or vice versa, is moved towards this end plate to enlarge the mandrel. diameter si, that the support wings (30) which are slidably connected to the rails (56) in the longitudinal direction of the longitudinal direction of the conical middle part (101) slidably to the rails (44) in the tapered middle part, the intermediate end plates (26, 28) slid leaking thereto by the conical center part. 5 Method according to claim 2, characterized in that. that the conical center portion is moved hydraulically or pneumatically within the mandrel. Device for centering or attaching a tubular piece (14), comprising: - a mandrel (16) formed by a central part (38) arranged between end plates (26, 28) which is at least partially conical and directed in the axial direction of the piece to be machined, and the middle portion movable in the axial direction of the piece to be machined; and - support wings (30) having the same direction as the axle of the tubular piece to be machined. and which are arranged radially between the end plates, and which are movably coupled to the center portion (38) such that a movement of the center portion, in the direction of its axis, forces the support wings to move radially so as to enlarge or reduce the effective diameter of the mandrel, characterized therein. the support wings (30), whose periphery (36) has a shape corresponding to the shape on the inside of the piece to be machined, radially arranged on a conical center part (38) which b by radially arranged outriggers, such that each support wing is read at a rail (44) on the conical center part by means of a T-shaped latch (56) formed on the outrigger or the like, so that the support wing can move along the rail to center or fasten various Large tubular pieces, which in their cross-section are cylindrical, square or polygonal or equivalent. Device according to claim 4, characterized in that the support wings (30) are slidably arranged in relation to the top and bottom plates (26, 28). 101270 Device according to claim 4 or 5, characterized in that. - the tapered center portion (38) tapered against the top plate (26), - the peripheral of the tapered portion is formed by radially arranged wedge-shaped outlets (42), the outer surface of which is arranged in the longitudinal direction of the periphery to its cross-section T-shaped or corresponding rails (44). ), the p & auxiliary wings (30) are formed T-shaped or corresponding latches (56) parallel to the rails (44), and the 10. the rails (44) in the conical center part (38) are arranged to engage the latches (56), whereby the support wings are slidable Iästä at the middle. Device according to claim 6, characterized in that. that in the mandrel (16) is arranged support wings (30), in which the middle portions (58) are formed, which in their shape correspond to the wedge-shaped outlets (42) pk the tapered middle part, and on the bottom of the rail corresponding to the rails. shaped rafters (56), and that 20. the support wings (30) by means of the T-shaped rafters (56) are slidably attached to the rails (44) of the wedge-shaped outlets (42). 8. Device according to claim 6 or 7, characterized therein. that the peripheral of the conical center portion is formed by 6 - 10, advantageously 8, radially arranged wedge-shaped outlets (42), and that in the mandrel 6-10, advantageously 8, support wings (30) are arranged. Device according to claim 4, characterized in that. that the outer periphery (36) of the support wings is curved, advantageously having the same shape as the inner surface of the piece to be machined. Use of a device according to any of claims 4-9, characterized in that. that the device is used in assembling electric motors to center the stator whereby the motor housing (12) is pressed onto the wrapped stator or when joining and compressing the stator discs, whereby - the mandrel (16) is placed on the mounting table (18), The stator (14) or the stator discs are placed on the mandrel (16) and the pressing of the housing (12) or the stator discs is carried out by means of a press cart (24). Use according to any of claims 4-9, characterized in. that the device is used to center a cylinder-shaped piece when machining the outer shell of the piece. * t