JP2001069731A - Method for manufacturing windings of rotating electric machines - Google Patents

Abstract

(57) [Summary] [Problem] A rotation capable of preventing deterioration of an insulating film due to twisting of a tip end for a coil end of a conductor segment while avoiding addition of a complicated manufacturing process and suppressing an increase in manufacturing work and manufacturing cost. To provide a method for manufacturing a winding of an electric machine. A plurality of pin-shaped jigs are inserted substantially radially adjacent to the base end of each coil end tip end protruding from one end face of a stator core in the circumferential direction. Since the base end of the coil end distal end portion S is circumferentially twisted with the pin-shaped jig 300 having a round cross section as a fulcrum,
Compared to the conventional method of twisting the base end of the coil end tip S with the cross section perpendicular to the slot peripheral part of the core 200 as a bending fulcrum, the stress concentration at the base end of the coil end tip S is remarkably reduced. Can be.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a winding of a rotating electric machine.

[0002]

2. Description of the Related Art WO92 / 06527 (PCT / DE9)
No. 1/00738) discloses that a large number of U-shaped or I-shaped (straight) conductor segments are inserted into each slot of a stator core from one end face of the core, and the coils of these conductor segments protrude toward the other end face of the core. It discloses that the end portion for the end is bent (twisted) in the substantially circumferential direction in the vicinity of one end surface of the core, and then the pair of tip portions of each coil end portion are joined to form a stator coil.

[0003]

However, since the above-described bending of the end portion of the conductor segment for the coil end is performed using the peripheral portion of the slot on the end surface of the stator core as a fulcrum for bending, the end surface of the peripheral portion of the slot at a substantially right angle is used. As a result, local bending stress concentrates on the insulating film at the base end of the tip end for the coil end, and the strength may be degraded.

In order to solve this problem, it is conceivable to reduce the bending stress by adding an R to the periphery of the slot of the stator core. However, there is a drawback that a problem arises in that the manufacturing process is not negligibly complicated. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is an object of the present invention to avoid an additional complicated manufacturing process, to suppress an increase in manufacturing work and manufacturing costs, and to perform insulation by twisting a tip end for a coil end of a conductor segment. It is an object of the present invention to provide a method for manufacturing a winding of a rotating electric machine capable of preventing deterioration of a film.

[0006]

According to a first aspect of the present invention, there is provided a method for manufacturing a winding of a rotary electric machine, wherein a plurality of coil end protruding from one end face of a core are individually provided in a circumferential direction at a base end thereof. A large number of pin-shaped jigs are inserted approximately in the radial direction adjacent to the core, and the base end of the coil end tip is twisted in a predetermined direction with the pin-shaped jig having a round circumferential section as a fulcrum. As compared with the conventional method in which the base end of the distal end for the coil end is twisted using the cross section perpendicular to the section as the bending fulcrum, the stress concentration at the base end of the distal end for the coil end can be remarkably reduced. This is because the pin-shaped jig has a round cross section in the circumferential direction, and the pin-shaped jig can be elastically deformed when the coil end tip is twisted.

As a result, according to the present configuration, it is possible to avoid the addition of a complicated manufacturing process, and to prevent the deterioration of the insulating film due to the twisting of the coil end tip of the conductor segment while suppressing an increase in manufacturing work and manufacturing costs. A possible method of manufacturing a winding of a rotating electric machine can be realized.

For example, in the step of bending the segment conductor tip portion, a guide member provided radially outside the slot is prepared, and each pin-shaped jig is radially penetrated through the end face of the wheel-plate-shaped base. Through the guides so that they can be displaced in the radial direction, push each pin-shaped jig radially inward along the guides, and move the end of each pin-shaped jig along the end face of the core to the coil end of the segment conductor. It can be carried out by a method such as individually adjoining in the circumferential direction to the tip of the tool, and in this case, the work of inserting each pin-shaped jig can be simplified.

According to a second aspect of the present invention, in the method for manufacturing a winding of a rotary electric machine according to the first aspect, the coil end of the segment conductor projecting from the other end surface of the core and constituting the coil end on the other end side of the core. In the state where the base end for use is extended in the axial direction near the other end surface of the core, the step of bending the tip end of the segment conductor is performed.

With this configuration, in the bending step of the segment conductor distal end portion, when the coil end distal end portion of the segment conductor is twisted in the circumferential direction, the insulating film of the coil end proximal end portion of the segment conductor becomes the other end surface of the core. Can be prevented from being damaged by the corner of the peripheral edge of the slot.

More specifically, when the tip end for the coil end projecting from one end face of the core is twisted in the circumferential direction, the segment conductor is urged to be pulled out of the slot on one end face of the core, thereby The segment conductor is forced into the slot while being strongly pressed against the core corner around the opening at the other end of the slot. At this time, if the segment conductor is bent, insulation of the base end for the coil end will occur. The coating is damaged at the corners of the core. Therefore, by setting the base end for the coil end in this part in the same direction as the slot in advance,
This problem can be solved.

According to a third aspect of the present invention, in the method of the first aspect, the coil ends of the segment conductors projecting from the other end surface of the core and constituting the coil end on the other end side of the core. The bending step of the segment conductor distal end portion is performed while holding the base end portion of the segment conductor so as not to be displaceable in the circumferential direction.

With this configuration, when the coil end on the one end side of the core is twisted in the circumferential direction to form the coil end, the segment conductor for forming the coil end on the other end side of the core is formed. The coil end base end is urged in the circumferential direction to be twisted, and the insulating film of the coil end base end can be prevented from being damaged at the core corner.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the following examples.

[0015]

(Preparation of U-shaped conductors A to D and rear-side twisting jig 1) First, as shown in FIG. 1, a rear-side twisting jig 1 is prepared.

In the rear twisting jig 1, an outer ring-shaped jig (first jig) 11 is rotatably accommodated in a ring-shaped fixed frame 10, and an inner ring jig is radially inside the outer ring-shaped jig. The jig (second jig) 12 is rotatably accommodated.

On the end surfaces of the outer ring-shaped jig 11 and the inner ring-shaped jig 12, through holes 13 and 14 are provided at the same positions as slots of a stator core of an alternator to be described later. The through-hole 13 of the outer ring-shaped jig 11 is set at the same position on the outer peripheral half of the slot, and the through-hole 14 of the inner ring-shaped jig 12 is set at the same position on the inner peripheral half of the slot.

Next, the U-shaped conductor A for the intermediate portion having a large round shape,
The required number of small-turn U-shaped conductors B for the middle portion, U-shaped conductors C for drawing, and U-shaped conductors D for interlayer connection are prepared.

Here, the number of slots is 96, each of A and B is 90, and each of C and D is six. Each of the U-shaped conductors A to D has a pair of straight portions S extending linearly at a predetermined interval from each other, and a curved portion UU connecting the base ends of these straight portions S, S.

As shown in FIG. 2, each slot 201 of the stator core 200 has a first position
1, a second position S2, a third position S3, and a fourth position S4 are set, and between the straight portions S of the U-shaped conductors A to D, such that the straight portions S are accommodated in these four positions. The interval is set.

More specifically, the distance between the U-shaped conductors A is set so that both straight portions S can be individually inserted into the first position S1 and the fourth position S4. The straight portions S are set so as to be individually insertable into the second position S2 and the third position S3, and the distance between the U-shaped conductors C is such that both straight portions S are individually inserted into the first position S1 and the third position S3. The space between the U-shaped conductors D is set so that both straight portions S can be individually inserted into the second position S2 and the fourth position S4.

(Step of inserting each U-shaped conductor A to D into rear twisting jig 1) Next, as shown in FIG.
D is sequentially inserted into the through holes 13 and 14 of the rear-side twisting jig 1. Note that the two straight portions S of one U-shaped conductor are individually inserted into one predetermined through-hole 13 and one predetermined through-hole 14 which are radially adjacent to each other (located at equal positions in the circumferential direction). .

Therefore, the through-hole 13 of the outer ring-shaped jig (first ring) 11 is in the first position S of the slot 201.
1, formed at the same position at the second position S2, and the through hole 14 of the inner ring-shaped jig (second ring) 12 is formed at the same position at the third position S3 and the fourth position S4 of the slot 201. Hereinafter, for the sake of simplicity, a position corresponding to the first position S1 of the through hole 13 is similarly referred to as a first position S1,
A position corresponding to the second position S2 of the through hole 13 is also referred to as a second position S2, a position corresponding to the third position S3 of the through hole 14 is also referred to as a third position S3, and a fourth position S4 of the through hole 14 Is also referred to as a fourth position S4.

Accordingly, the U-shaped conductors A and B, that is, the U
A pair of U-shaped conductors or a pair of U-shaped conductors C and D, that is, a pair of U-shaped conductors for end portions are inserted.

As will be described later, the straight portions S of the U-shaped conductors A and B are connected in pairs at the front side of the stator core 200, respectively, and a total of six phases of phase coils (U, V, W,
(X, Y, Z).

The U-shaped conductor D is a large-round U
A U-shaped conductor for interlayer connection for serially connecting one end of the phase coil formed of the U-shaped conductor A and one end of the phase coil formed of the U-shaped conductor B for the intermediate portion having a small round shape.

The U-shaped conductor C is composed of the other end of the phase coil composed of a large-round U-shaped conductor A for an intermediate portion and the other end of the phase coil composed of a small-circular U-shaped conductor B for an intermediate portion. And a U-shaped lead-out conductor that constitutes both ends of a coil for one phase of the three-phase winding by cutting off the bent portion UU as described later. Therefore, the U-shaped conductor C is formed to be longer in the axial direction than the other U-shaped conductors A, B, and D so as to also serve as a lead wire later.

As shown in FIG. 3, a total of four straight portions S of a pair of U-shaped conductors C and D are inserted into a pair of through holes 13 and 14 which are radially adjacent at equal circumferential positions. The bent portion UU of the U-shaped conductor D for interlayer connection is bent in the circumferential direction. Thereby, one of the straight portions S of the U-shaped conductor C for drawing is connected to the third position S3 of the through-hole 14 of the inner ring-shaped jig 12 of the rear side twisting jig 1 at the third position S3. It can be inserted without being disturbed by the conductor D.

(Preparation of jig 2 for holding U-shaped conductor for intermediate portion) Next, the intermediate portion having a hole through which the U-shaped conductor C penetrates while holding the curved portions UU of the U-shaped conductors A, B, and D A jig for holding U-shaped conductor 2 is prepared.

FIG. 4 is a partially cutaway perspective view of the jig 2 for holding the U-shaped conductor for the intermediate portion, and FIG.

The jig 2 is a shallow trough-shaped member, and a bottom portion 21 has a hole 22 through which a U-shaped conductor C for drawing out passes.
Are formed, and a hole 23 having a circumferential width twice as large as that of the hole 22 is formed. One drawer U-shaped conductor C can be inserted into each of the holes 22, and two drawer U-shaped conductors C can be inserted into the hole 23 (see FIG. 6).

Each U-shaped conductor A,
A predetermined number of pairs of gripping projections 24 for individually gripping the central portions of the curved portions UU of B and D are provided over one circumference.

(Holding of U-shaped conductors A to D by jig 2)
Through holes 13 and 14 of rear twisting jig 1 by the above-described steps.
Curved portions UU of the respective U-shaped conductors A to D inserted in a predetermined arrangement
Then, as shown in FIG. 6, the jig 2 is put on, and the jig 2 is supported so as not to rotate. At this time, the draw-out U-shaped conductor C that is long in the axial direction projects from the holes 22 and 23 in the axial direction. FIG. 7 shows the holding state of each of the U-shaped conductors A to D.

(Shaping of the rear-side crossover conductor by reverse rotation (twisting) of the rear-side twisting jig 1) Next, as schematically shown in FIG. The tool 11 and the inner ring-shaped jig 12 are rotated in a direction opposite to each other by a predetermined angle (the electrical angle π as a whole). Note that in FIG.
Are not shown.

Thus, a rear-side transition conductor portion T (see FIG. 8) which is bent in the circumferential direction is formed, and the U-shaped conductors A to D are respectively U-shaped conductors A 'to D' having the transition conductor portion T. (See FIG. 9). In FIG. 8, S represents U-shaped conductors A 'to D'.
Is a straight line portion. In FIG. 8, the U-shaped conductors A and B
Only changes to the A-shaped conductors A 'and B' are shown.

Note that, despite the reverse rotation of the jigs 11 and 12, the bent portion UU of the U-shaped conductor C for drawing and the pair of straight portions S adjacent thereto are formed by the holes 22 and 23 of the jig 2. It does not deform because it is inserted into

(Preparation of Stator Core 200 and Front Twisting Jig 4) Next, the stator core 200 and the front twisting jig 4 are prepared. The stator core 200 is as described above.

As shown in FIG. 12, the front twisting jig 4 includes an outer ring jig 11 and an inner ring jig 12.
Is divided into two.

More specifically, the front-side twisting jig 4
As shown in FIG. 10, a ring-shaped fixed frame 40
Are provided with four ring-shaped jigs 41 to 44 which are rotatable from the outside to the inside in the radial direction.

A through hole (first position through hole) is provided on the end face of the ring jig 41 in the axial direction at the same position in the circumferential direction and the radial direction at the first position S1. A through hole (a second position through hole) is provided in the end face in the axial direction at a position equal to the second position S2 in the circumferential direction and the radial direction, and the end face of the ring-shaped jig 43 is provided in the third position S3. A through hole (third position through hole) is provided in the axial direction at the same position in the circumferential direction and the radial direction, and the end face of the ring-shaped jig 44 is positioned at the same position in the circumferential direction and the radial direction as the fourth position S4. A through hole (fourth position through hole) is provided in the axial direction.

The front end face of the stator core 200 is brought into close contact with the end face of the front twisting jig 4, and each slot is aligned with each through hole of the ring jigs 41 to 44.

(Transfer process of U-shaped conductor) Next, the U-shaped conductors A 'to D', each having a crossover conductor portion, are kept in the jig 2 while maintaining their arrangement state (FIG. 9). ), And is removed from the jig 1 and inserted into each slot from the rear end face of the stator core 200 (see FIG. 10). Thereby, the exfoliated front ends of the straight portions S of the U-shaped conductors A ′ to D ′ are individually inserted into the through holes of the jig 4 through the slots.

The U-shaped conductors A 'to D' are inserted into the slots of the stator core 200 by the U-shaped conductors A 'to D'.
Is stopped in a state where the straight portion S slightly protrudes from the rear end face of the stator core 200. As a result, the base end for coil end of the segment conductor referred to in the present invention extends in the axial direction near the rear end face (the other end face) of the stator core 200 by the straight portion S.

This is because strong bending stress is applied to the insulating film at the boundary between the transition conductor portion (circumferential bent portion) T and the straight portion S of each of the U-shaped conductors A 'to D'. In order to prevent the U-shaped conductors A ′ to D ′ from coming into contact with the rear end face on the rear side of the stator core 200 and being torn or degraded by a further strong bending stress in the subsequent torsion on the front side. is there.

(Pin-shaped Jig Inserting Step) Next, as shown in FIG.
A predetermined distance away from the front end surface 201 at the axial direction. Next, in the vicinity of the end face 201 of the stator core 200, at a position circumferentially adjacent to the linear portion S of each of the U-shaped conductors A 'to D' protruding frontward from the end face 201,
A large number of pin-shaped jigs 300 are individually inserted from the radial outside to the radial inside. As a result, each pin-shaped jig 300 sandwiches the linear portion S of each of the U-shaped conductors A ′ to D ′ in the circumferential direction near the front end surface 201 of the stator core 200.

Although the cross section of the pin-shaped jig 300 is circular, the U-shaped conductors A 'to D' need not be circular as long as the side facing the linear portion S is a curved surface having a predetermined curvature.

(Step of Forming Front Crossover Conductor) Next, as shown in FIG. 12, the ring-shaped jigs 41 and 43 are rotated by π / 2 in one direction, and the ring-shaped jigs 42 and 44 are moved. Rotate in the opposite direction by π / 2. Since the U-shaped conductors A 'to D' are held by the stator core 200, the U-shaped conductors A 'to D'
The straight portions S protruding forward from the stator core 200 of D ′ are bent in the circumferential direction with the pin-shaped jig 300 as a bending fulcrum. As a result, these straight portions S are deformed substantially in the circumferential direction and cross over the front side. It becomes a conductor.

Thereafter, the pin-shaped jig 300 is pulled out radially, and the straight portions S of the U-shaped conductors A 'to D' are pulled out from the through holes of the ring-shaped jigs 41 to 44. U
The jig 2 for holding the U-shaped conductor is removed from each of the U-shaped conductors A ′ to D ′. It should be noted that the jig 2 for holding the U-shaped conductor for the intermediate portion is not removed until this stage because the U-shaped conductors 41 to 44 for producing the front-side transition conductor are rotated when the ring-shaped jigs 41 to 44 are rotated.
This is to prevent the bent portions UU of the U-shaped conductors A 'to D' from protruding toward the rear side in the axial direction and from being twisted in the circumferential direction.

In place of the jig 2 for holding the U-shaped conductor for the intermediate portion, as shown in FIG.
At 0, the front end of the U-shaped conductors A 'to D' may be chucked at the front end of the transitional conductor portion on the rear side to perform the front twisting operation.

Next, a large-shaped U-shaped conductor A 'for an intermediate portion is used.
And the distal end of the second position S2 of the U-shaped conductor B 'for the intermediate portion, which is a small turn and is π apart from the U-shaped conductor A' by an electrical angle, is brought into close contact with the distal end E of the first position S1. Similarly, the tip E of the fourth position S4 of the U-shaped conductor A 'for the intermediate portion having a large turning shape,
This U-shaped conductor A 'is brought into close contact with the tip of the third position S3 of the small-sized U-shaped conductor B' for the intermediate part which is separated by π in electrical angle.

The leading end E of the first position S1 of the lead-out U-shaped conductor C 'and the intermediate U-shaped conductor B' having a small turning shape and having an electrical angle of π away from the U-shaped conductor C '. Two position S2
In close contact with the tip. Similarly, the leading end E of the third position S3 of the U-shaped conductor C 'for extraction and the U-shaped conductor C'
And a U-shaped conductor A 'for the middle part with a large roundabout separated by an electrical angle of π
At the tip of the fourth position S4.

Further, the front end portion E of the second position S2 of the U-shaped conductor D 'for interlayer connection and the U-shaped conductor A' for the intermediate portion having a large roundabout and an electrical angle of π from the U-shaped conductor D '. The tip of one position S1 is brought into close contact. Similarly, the tip end E of the fourth position S4 of the U-shaped conductor D 'for interlayer connection and the third position of the U-shaped conductor B' for the intermediate portion having a small turning distance of π in electrical angle from the U-shaped conductor D '. The tip of S1 is brought into close contact.

These end contact operations are performed in preparation for the next welding step.

(Welding step) Next, as shown in FIG.
The tip E of each pair of adjacent U-shaped conductors A 'to D',
E is welded in pairs to complete the front-side transition conductor portion, thereby forming six-phase coils of U, V, W, X, Y, and Z, and connecting these six-phase coils to form a three-phase coil. The stator coil (winding in the present invention) is almost completed (FIG. 1).
5).

(Step of Cutting Out the Curved Part UU of the Lead-out U-shaped Conductor C ') Next, the straight portion S of each lead-out U-shaped conductor C'
Are cut at suitable cutting positions 300 and 301 (see FIG. 16), the resin is peeled off from the tip portion 400, and each is bent by a predetermined distance in the circumferential direction to form a lead wire 500 (see FIG. 17).

Six phase coils each having a pair of lead wires are formed. FIG. 19 shows the lead-out position of the lead wire 500 of each phase coil.

In this embodiment, a total of six phase coils are manufactured. Therefore, at least six lead-shaped U-shaped conductors C are provided for leading both ends of each phase coil, and six interlayer connection U-shaped conductors D are provided inside each phase coil for interlayer connection. Is done.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one step of a method for manufacturing a winding of a rotating electric machine according to the present invention.

FIG. 2 is a partial front view showing the vicinity of a slot of a stator core.

FIG. 3 is a perspective view of a U-shaped conductor for extraction and a U-shaped conductor for interlayer connection.

FIG. 4 is a perspective view of a jig for holding a U-shaped conductor for an intermediate portion.

FIG. 5 is a front view of a jig for holding a U-shaped conductor for an intermediate portion.

FIG. 6 is a perspective view showing one step of a method for manufacturing a winding of a rotary electric machine according to the present invention.

FIGS. 7A and 7B show a state in which each U-shaped conductor is held or pressed by a jig for holding a U-shaped conductor for an intermediate portion, wherein FIG. 7A is a side view and FIG.

FIG. 8 is a perspective view showing one step of a method for manufacturing a winding of a rotary electric machine according to the present invention.

FIG. 9 is a perspective view showing one step of the method for manufacturing a winding of a rotary electric machine according to the present invention.

FIG. 10 is a perspective view showing one step of a method for manufacturing a winding of a rotary electric machine according to the present invention.

FIG. 11 is a schematic side view showing one step of the method for manufacturing a winding of a rotating electric machine according to the present invention.

FIG. 12 is a schematic side view showing one step of the method for manufacturing a winding of a rotary electric machine according to the present invention.

FIG. 13 is a schematic side view showing a deformation step of the method for manufacturing a winding of a rotating electric machine according to the present invention.

FIG. 14 is a schematic side view showing one step of the method for manufacturing a winding of a rotary electric machine according to the present invention.

FIG. 15 is a perspective view showing a state before a stator cutting step using the method for manufacturing a winding of a rotating electric machine according to the present invention.

FIG. 16 is a perspective view showing a cutting step of the U-shaped conductor for extraction.

FIG. 17 is a perspective view showing a lead wire forming step by bending a lead U-shaped conductor.

FIG. 18 is a perspective view showing a completed stator.

FIG. 19 is a perspective view showing a lead-out position of a lead wire in the stator of FIG. 16;

[Explanation of symbols]

1 is a rear-side twisting jig, 2 is a jig for holding a U-shaped conductor for an intermediate portion, 4 is a front-side twisting jig, 11 is a first ring (outer ring-shaped jig), and 12 is a second ring (inner ring). Jig), 200 is a stator core (core), 300 is a pin-shaped jig, A is a U-shaped conductor for an intermediate portion having a large round shape, B is a U-shaped conductor for an intermediate portion having a small round shape, and C is a U-shaped for drawing. conductor,
D is a U-shaped conductor for interlayer connection, UU is a curved part, and S is a straight part.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yu Sugiyama 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in Denso Corporation (reference) 5H603 AA04 AA09 BB02 BB12 CA01 CB03 CB11 CC03 CC17 CD22 CD33 CE01 CE05 5H615 AA01 BB02 BB14 PP01 PP08 PP14 QQ03 QQ12 QQ27 SS04 SS10 SS15

Claims (3)

[Claims] An even number of segment conductors are inserted radially apart from each other in a large number of slots formed in the core inner peripheral surface at a predetermined pitch in the circumferential direction and substantially in the axial direction. A segment conductor insertion step of causing the distal end portion to protrude from one end surface side of the core, a segment conductor distal end bending step of twisting the coil end distal end portion of each of the segment conductors by a predetermined angle in a substantially circumferential direction near one end surface of the core, And a segment conductor tip joining step of joining the tip of each of the coil end tips one by one to complete the coil end on one end side of the core. In the distal end bending step, the base end of each of the coil end distal ends protruding from the one end face of the core is circumferentially arranged along one end face of the core. A large number of pin-shaped jigs each having a round cross-section in the circumferential direction are inserted substantially in the radial direction while being individually adjacent to each other, and the coil end tip on one end side is twisted in a predetermined direction with the pin-shaped jig as a fulcrum. A method for manufacturing a winding of a rotating electric machine, characterized by comprising: 2. The method for manufacturing a winding of a rotating electrical machine according to claim 1, wherein a base end for the coil end of the segment conductor, which protrudes from the other end surface of the core and forms a coil end on the other end side of the core, is provided. And a step of bending the end portion of the segment conductor in a state of being extended in the axial direction near the other end surface of the core. 3. The method for manufacturing a winding of a rotating electric machine according to claim 1, wherein a base end for the coil end of the segment conductor, which protrudes from the other end surface of the core and constitutes a coil end on the other end side of the core, is provided. A method of manufacturing a winding of a rotating electrical machine, wherein the step of bending the end portion of the segment conductor is performed while holding the segment conductor so as not to be displaceable in the circumferential direction.