JP2024043381A - How to remove insulation coating from flat wire - Google Patents

Abstract

[Problem] To provide a method for stripping an insulating coating from a rectangular wire that can strip the insulating coating without leaving any insulating coating behind. [Solution] The method for stripping an insulating coating from a rectangular wire includes a first stripping step for stripping the insulating coating from two opposing sides (long sides) of the rectangular wire over a predetermined range along the length of the rectangular wire, a corner moving step for moving the positions of the ridgelines formed by both end points of the two sides along the length of the rectangular wire outward over a predetermined range, a chamfering step for forming a chamfered portion at the corner including the ridgeline that has been moved outward over a predetermined range, and a second stripping step for stripping the insulating coating from two sides (short sides) of the rectangular wire over a predetermined range, in that order. [Selected Figure] Figure 2

Description

The present invention relates to a method for removing an insulation coating from a flat wire.

Conventionally, a method has been proposed in which, before peeling off the insulation coating of a rectangular wire used for a motor stator coil, for example, the chamfering is performed by plastically deforming both ends of two opposing sides of the rectangular wire (Patent Document (see 1).

JP2021-40441A

However, in the method for manufacturing a rectangular wire disclosed in Patent Document 1, there is a possibility that the insulating coatings on the left and right side surfaces of the rectangular wire may penetrate inside when the rectangular wire is plastically deformed. Therefore, when the insulation coatings on the left and right sides of the rectangular wire are peeled off in a subsequent process, there is a risk that the insulation coatings that have penetrated inside may remain.

An object of the present invention is to provide a method for stripping an insulating coating from a rectangular wire, which allows stripping without leaving any insulating coating.

In order to achieve the above object, the insulating coating peeling method for a rectangular wire of the present invention includes a first step of peeling off the insulating coating on two opposing sides of the rectangular wire over a predetermined range along the length direction of the rectangular wire. a peeling step, a corner moving step in which the positions of the ridge lines formed by both end points of the two sides are moved outward over a predetermined range along the length direction of the rectangular wire; a chamfering step in which a chamfer is formed on a corner including the ridgeline that has been moved; a second peeling step in which the insulation coating on two sides orthogonal to the two sides of the flat wire is peeled off over a predetermined range; It is characterized by performing the following in order.

According to this configuration, it is possible to peel off the insulating film without leaving it behind.

In addition, in the method for removing an insulating coating on a flat wire according to the present invention, the corner moving step includes moving the corners along the length direction of the flat wire in the vicinity of the ridge lines on two opposing sides of the flat wire over a predetermined range. Then, a first mold having an abutting portion having a smaller cross-sectional area toward the tip is pressed against the mold.

According to this configuration, the machining related to the corner moving process can be realized using the curved blade, so that periodic replacement of the blade can be made unnecessary.

In addition, in the method for stripping the insulating coating from a rectangular wire according to the present invention, the corner moving process presses a second die having abutting portions with a smaller cross-sectional area toward the tip along the length of the rectangular wire at approximately the center of two opposing sides of the rectangular wire over a specified range.

According to this configuration, the machining related to the corner moving process can be realized using the curved blade, so that periodic replacement of the blade can be made unnecessary.

The present invention provides a method for removing the insulating coating from rectangular wire that can remove the coating without leaving any insulating coating behind.

FIG. 1 is an external perspective view showing an example of a rectangular wire with an insulating coating peeled off. FIG. 2 is a flowchart illustrating an example of a procedure for removing an insulating coating from a rectangular wire. FIG. 3 is a diagram illustrating a method of peeling off the insulating coating on the long sides of the rectangular wire. FIG. 4A is a diagram illustrating a method of moving the corners of a rectangular wire. FIG. 4B is a diagram showing another form of the curved blade used for moving the corners of a flat wire. FIG. 5 is a diagram illustrating a method of chamfering the corners of a rectangular wire. FIG. 6 is a diagram illustrating a method for removing the insulating coating from the short sides of a rectangular wire. FIG. 7 is a diagram illustrating a method for forming a recess on a rectangular wire. FIG. 8 is a diagram illustrating a method for cutting and chamfering a rectangular wire. FIG. 9 is a diagram illustrating another method of moving the corners of a rectangular wire.

The following describes in detail an embodiment of the present invention with reference to the attached drawings.

(Schematic structure of rectangular wire with insulating coating peeled off)
The schematic structure of a rectangular wire from which an insulating coating has been peeled off according to the present invention will be described with reference to Fig. 1. Fig. 1 is an external perspective view showing an example of a rectangular wire from which an insulating coating has been peeled off.

The rectangular wire 10 has a structure in which an insulating coating 13 is formed on the surface of a conductor 12 having a rectangular cross section. The stator coil of the motor is formed by peeling off the insulating coating 13 at the tip of the rectangular wire 10 to expose the conductor 12, and welding different conductors 12 together.

FIG. 1 shows an example of a state in which the insulation coating 13 on the tip of a flat wire 10 is peeled off using the insulation coating peeling method of the present disclosure.

The rectangular wire 10 has a rectangular cross section defined by a long side 14a extending along the Y-axis and a short side 14b extending along the Z-axis. The inside of the rectangular wire 10 is formed of a conductor 12 having electrical conductivity such as copper, and the outside thereof is covered with a non-conductive insulating film 13 such as enamel. The insulating coating 13 is peeled off from the tip of the rectangular wire 10, so that the conductor 12 is exposed. In this embodiment, the long side 14a is described as being longer than the short side 14b, but the long side 14a and the short side 14b may have the same length. Further, the long side 14a and the short side 14b may be reversed. That is, in the following description, where the long side 14a and the short side 14b are written, the long side 14a may be read as the short side 14b, and the short side 14b may be read as the long side 14a.

At the tip of the rectangular wire 10 from which the insulating coating 13 has been peeled off, there are formed upper and lower surfaces 15a, left and right surfaces 15b, and a tip surface 15c. The upper and lower surfaces 15a are surfaces formed along the length direction of the conductor 12 and along the XY plane. The left and right surfaces 15b are surfaces formed along the length direction of the conductor 12 and along the XZ plane. The tip surface 15c is a surface formed at the tip of the conductor 12 and along the YZ plane.

A chamfered portion 16a is formed at a ridgeline (corner) that is an intersection line between the upper and lower surfaces 15a and the left and right surfaces 15b of the conductor 12. Furthermore, a chamfered portion 16b is formed at the intersection of the left and right surfaces 15b and the tip end surface 15c of the conductor 12. Further, a chamfered portion 16c is formed at the intersection of the upper and lower surfaces 15a of the conductor 12 and the tip end surface 15c. By forming these chamfered portions 16a, 16b, and 16c, when performing insulating powder coating for insulation on the coil formed by welding the conductor 12 in a later process, the powder sprayed on the conductor is Since it reliably adheres to the chamfered portion 12, a strong insulating film can be formed.

(Flow of insulating coating peeling process)
The flow of the process for peeling off the insulating coating 13 of the rectangular wire 10 will be explained using FIG. 2. FIG. 2 is a flowchart illustrating an example of a procedure for removing an insulating coating from a rectangular wire.

First, the insulating coating 13 is peeled off over a predetermined range R along the long side 14a of the flat wire 10 (step S1). The processing method performed in step S1 will be described in detail later (see FIG. 3). Note that the process of step S1 is an example of the first peeling process in the present disclosure.

Next, a movement process is performed in which the positions of the ridge lines (corners) at both ends of the long side 14a from which the insulating coating 13 has been peeled are slightly moved outward over a predetermined range R (step S2). The processing method performed in step S2 will be described in detail later (see FIG. 4a). Note that the step S2 is an example of a corner moving step in the present disclosure.

Next, a chamfering process is performed to form a chamfered portion 16a at a corner including the ridgeline moved outward in step S2 (step S3). The processing method performed in step S3 will be described in detail later (see FIG. 5). Note that the process of step S3 is an example of a chamfering process in the present disclosure.

Next, the insulating coating 13 is peeled off along the short side 14b of the rectangular wire 10 (step S4). The processing method performed in step S4 will be described in detail later (see FIG. 6). The process in step S4 is an example of the second peeling process in this disclosure.

Next, recess processing is performed to form recesses 20a, 20b (see FIG. 7) and chamfered portions 16b on both side surfaces of the conductor 12 (step S5). The processing method performed in step S5 will be described in detail later (see FIG. 7).

Finally, the conductor 12 is cut at a position passing through the depressions 20a and 20b, and a chamfering process is performed to form a chamfered portion 16c at the cut position (step S6). The processing method performed in step S6 will be described in detail later (see FIG. 8).

(Peeling of insulation coating along long sides)
The first peeling step of peeling off the insulating coating 13 along the long side 14a of the rectangular wire 10, which is performed in step S1 in FIG. 2, will be described in detail with reference to FIG. 3. FIG. 3 is a diagram illustrating a method of peeling off the insulating coating on the long sides of the rectangular wire. Note that the rectangular wire 10 is arranged along the X-axis, with the long side 14a (see FIG. 1) parallel to the Y-axis, and the short side 14b (see FIG. 1) parallel to the Z-axis. do.

Before processing, the rectangular wire 10 is elongated along the X-axis, as shown in FIG. 3(a). Here, the insulating coating 13 is peeled off along the long side 14a over a predetermined range R of the rectangular wire 10.

As shown in the A-A cross-sectional view, the rectangular wire 10 has an insulating coating 13 covering the conductor 12.

The insulating coating 13 is peeled off by applying the cutting blades 30a and 30b over a predetermined range R to the insulating coating 13 on the surface of the rectangular wire 10, as shown in FIG. This is done by moving along the Y axis. Specifically, as shown in the BB sectional view, with the pad 33 pressed against the negative side of the flat wire 10 in the Y-axis direction and the lower die 34 pressed against the positive side of the flat wire 10, the flat wire 10 is pressed. The cutting blade 30a is moved along the Z-axis negative side surface of 10 from the Y-axis negative side toward the positive side. Further, the cutting blade 30b is moved along the surface of the flat wire 10 on the Z-axis positive side from the Y-axis negative side toward the positive side. Thereby, the cutting blades 30a and 30b each cut the insulating coating 13 along the XY plane of the rectangular wire 10 over a predetermined range R.

As a result, the conductor 12 is exposed in a predetermined range R, as shown in FIG. 3(c).

(Movement machining of corners)
The corner moving step of moving the corner of the rectangular wire 10 performed in step S2 in FIG. 2 will be described in detail with reference to FIGS. 4A and 4B. FIG. 4A is a diagram illustrating a method of moving the corners of a rectangular wire. FIG. 4B is a diagram showing another form of the curved blade used for moving the corners of a flat wire.

In this step, as shown in FIG. 4A(a), a mold 40a is pressed against the rectangular wire 10 from the Z-axis negative side to perform molding (for example, plastic deformation by coining). Further, molding is performed by pressing the mold 40b from the positive side of the Z-axis. A curved blade 42a and a curved blade 43a having the same height are formed over a predetermined range R at the tip of the mold 40a. The cross-sectional area of the curved blades 42a, 43a becomes smaller toward the tips (positive side of the Z-axis), and the tips of the curved blades 42a, 43a extend along the X-axis to the conductor 12 over a predetermined range R of the flat wire 10. line contact with. Note that the curved blades 42a and 43a both have an inner side of the cutting edge along the Z axis, and an outer side of the cutting edge at an angle of about 45°. The curved blades 42a and 43a are pressed near the boundary between the insulating coating 13 and the conductor 12 formed on the short side (the side along the Z axis) of the rectangular wire 10, respectively. Here, the molds 40a and 40b are examples of the first mold in the present disclosure. Further, the curved blades 42a and 43a are examples of abutting portions in the present disclosure.

At the tip of the die 40b, curved blades 42b and 43b of equal height are formed over a predetermined range R. The curved blades 42b and 43b have a smaller cross-sectional area toward the tip (negative side of the Z axis), and the tips of the curved blades 42b and 43b make line contact with the conductor 12 along the X axis over the predetermined range R of the rectangular wire 10. The inside of the blade tip of each of the curved blades 42b and 43b is aligned along the Z axis, and the outside of the blade tip has an angle of about 45°. The curved blades 42b and 43b are each pressed against the vicinity of the boundary between the insulating coating 13 formed on the short side (side along the Z axis) of the rectangular wire 10 and the conductor 12. Here, the curved blades 42b and 43b are an example of abutting parts in this disclosure.

By pressing the curved blades 42a, 43a and the curved blades 42b, 43b against the flat wire 10, the flat wire 10 is plastically deformed toward the outside of the cutting edge. Due to this plastic deformation, the position of the ridge line 18 forming the corner of the rectangular line 10 along the X-axis changes from the position shown in FIG. 4A(a) to the position shown in FIG. 4A(b), that is, outward in the Y-axis direction. Moving. As a result, the ridge line 18 moves to the position of the ridge line 18a. Note that since the amount of pressing between the curved blades 42a, 43a and the curved blades 42b, 43b is small, the amount of plastic deformation of the flat wire 10 is also small, as shown in FIG. 4A(b).

Note that the angle of the cutting edge of the curved blade used for moving the corner is not limited to 45°. For example, as in a mold 44a shown in FIG. 4B, molding is performed using curved blades 46a and 47a in which the inside and outside of the blade edges each have an angle of 45 degrees, and the blade edges form an angle of 90 degrees. Similarly to FIG. 4A(b), the position of the ridge line 18 of the flat wire 10 can be moved to the position of the ridge line 18a.

(Chamfering of corners)
The corner chamfering step performed in step S3 of FIG. 2 will be described in detail with reference to FIG. 5. FIG. 5 is a diagram illustrating a method of chamfering the corners of a rectangular wire.

In this step, the chamfering process is performed by plastically deforming the four corners (area including the ridge line 18a) along the Z-axis that have been moved by the above-described corner movement process.

The chamfering process is performed by pressing a mold 50a against the rectangular wire 10 from the negative side of the Z-axis and pressing a mold 50b against the positive side of the Z-axis to perform molding (for example, plastic deformation by coining). A curved blade 52a and a curved blade 53a having the same height are formed over a predetermined range R at the tip of the mold 50a. The curved blades 52a and 53a have an inclined surface of about 25° with respect to the Y-axis direction. Note that the inclination of the inclined surface is not limited to 25°, and an appropriate angle is selected depending on the flat wire 10 to be processed.

When the inclined surfaces of the curved blades 52a and 53a of the mold 50a are pressed against the corners of the flat wire 10, chamfers are formed at the corners of the flat wire 10, as shown in FIG. 5(b). 16a is formed. At this time, the position of the ridge line 18a, which has been moved outward by the movement processing of the corner, is also plastically deformed along the Z-axis, and moves to the positive side of the Z-axis, as shown in FIG. 5(b).

Note that the mold 50b also includes a curved blade 52b and a curved blade 53b having the same structure as the mold 50a. The curved blade 52b and the curved blade 53b are pressed against the flat wire 10 from the positive side of the Z-axis to form a chamfered portion 16a.

(Peeling of insulation coating along the short side)
The second peeling step of peeling off the insulating coating 13 along the short side 14b of the rectangular wire 10, which is performed in step S4 of Fig. 2, will be described in detail with reference to Fig. 6. Fig. 6 is a diagram for explaining a method of peeling off the insulating coating on the short side of the rectangular wire.

In this step, after the above-described chamfering process is completed, the insulating coating 13 is peeled off along the short sides (sides along the Z axis) of the flat wire 10 over a predetermined range R of the flat wire 10.

As shown in FIG. 6(a), the insulating coating 13 is peeled off by cutting the cutting edges 60a and 60b over a predetermined range R near the boundary between the conductor 12 and the insulating coating 13 of the chamfered rectangular wire 10. This is done by moving it in the Z-axis direction. At this time, with the pad 63 pressed against the negative side of the flat wire 10 in the Z-axis direction and the lower mold 64 pressed against the positive side of the flat wire 10, the cutting blades 60a, 60b is moved from the negative side to the positive side of the Z-axis. As a result, the cutting blades 60a and 60b cut the insulating coating 13 along the XZ plane of the rectangular wire 10, respectively. At this time, the boundary between the conductor 12 and the insulating coating 13 is plastically deformed outward in the Y-axis direction due to the corner chamfering described above, so the insulating coating 13 is peeled off by the cutting blades 60a and 60b. At this time, no remaining insulating film 13 is formed.

(dent processing)
The recess machining performed in step S5 of FIG. 2 will be described in detail using FIG. 7. FIG. 7 is a diagram illustrating a method for forming a recess on a rectangular wire.

In this step, a recess 20a and a recess 20b along the Z-axis are formed approximately at the center of the left and right side surfaces along the XZ plane of the conductor 12 from which the insulating coating 13 has been peeled off.

The depressions 20a and 20b are formed by pressing a die 70a with a curved blade 72a and a die 70b with a curved blade 72b shown in FIG. 7(a) against the rectangular wire 10 from the negative side of the Z axis.

The curved blades 72a and 72b have a substantially U-shape, and by pressing against the conductor 12 of the flat wire 10, a portion of the left and right side surfaces of the conductor 12 are shaped into a substantially U-shape as shown in FIG. 7(b). Squeeze into shape. As a result, a depression 20a and a depression 20b are formed. Note that chamfered portions 16b are formed at the bases of the depressions 20a and 20b at positions on the left and right side surfaces of the conductor 12, respectively.

(Cutting and chamfering of flat wire)
The cutting and chamfering of the rectangular wire 10 performed in step S6 in FIG. 2 will be described in detail with reference to FIG. 8. FIG. 8 is a diagram illustrating a method for cutting and chamfering a rectangular wire.

In this step, the conductor 12 is cut at the positions of the depressions 20a and 20b formed by depression processing.

The conductor 12 is cut by moving the cutting blade 80 pressed against the position of the recess 20b along the Y axis to the position of the recess 20a, as shown in FIG. 8(a).

The cutting blade 80 includes an inclined portion 80a and an inclined portion 80b on the negative side of the Z-axis. Due to the inclined portions 80a and 80b, a chamfered portion 16c shown in FIG. 8(b) is formed at the cut end of the cut conductor 12 along the Y axis.

Further, the cutting blade 80 includes an inclined portion 80c and an inclined portion 80d on the positive side of the Z-axis. Due to the inclined portions 80c and 80d, a chamfered portion 16c is formed at the cut end of the cut conductor 12 along the Y axis.

By performing the above-described processing from step S1 to step S6 at predetermined intervals of the rectangular wires 10, a plurality of rectangular wires 10 with conductors 12 exposed at both ends are formed. These plural rectangular wires 10 are arranged adjacently around the stator core. Then, by welding the ends of adjacent flat wires 10 together, a stator coil wound around the stator core is formed.

(Operations and effects of this embodiment)
As explained above, the method for stripping the insulation coating of a flat wire according to the present embodiment is to remove the insulation coating 13 on two opposing sides (long sides 14a) of the flat wire 10 along the length direction of the flat wire 10. A first peeling step of peeling off over a predetermined range R, and a step of peeling outward over a predetermined range R of the positions of the ridge lines 18 formed by both end points of the long side 14a along the length direction of the flat wire 10, respectively. a chamfering step of forming a chamfered portion 16a on the corner including the ridgeline 18 moved outward over a predetermined range R; A second peeling step of peeling off the insulating coating 13 on the side 14b over a predetermined range R is performed in sequence. Therefore, the insulation coating 13 of the rectangular wire 10 can be peeled off without remaining.

In addition, in the method for peeling an insulating coating of a flat wire according to the present embodiment, the corner moving step includes, over a predetermined range R, near the ridgeline 18 of two opposing sides (long sides 14a) of the flat wire 10, A mold 40a (first mold) includes curved blades 42a, 43a (abutment portions) whose cross-sectional area is smaller toward the tip along the length direction of the flat wire 10, and a mold 40a (first mold) includes curved blades 42b, 43b (abutment portions). ) is pressed against the mold 40b (first mold). Therefore, by plastically deforming the area including the corner of the rectangular wire 10, it can be moved outward. Thereby, when the insulation coating 13 along the short side 14b is peeled off in a later step, the insulation coating 13 can be peeled off without remaining. Further, since processing is performed using the curved blades 42a, 43a, 42b, and 43b instead of cutting blades, the life of the blades can be extended.

(Modified example of embodiment)
Another method of moving the corners of the rectangular wire 10 will be described with reference to FIG. FIG. 9 is a diagram illustrating another method of moving the corners of a rectangular wire.

In FIG. 4A, a method was explained in which the curved blades 42a and 43a formed at the tip of the mold 40a and extending over a predetermined range R along the X-axis are pressed against the flat wire 10 to move the corners. , the method of moving the corners is not limited to this.

For example, as shown in FIG. 9(a), the position of the ridge line 18 formed by the corner of the rectangular wire 10 may be shifted outward by pressing a die 90a having a curved blade 92a at its tip, which has a predetermined range R along the X-axis, against approximately the center of the long side of the rectangular wire 10.

The cross-sectional area of the curved blade 92a becomes smaller toward the tip (positive side of the Z-axis), and the tip of the curved blade 92a makes line contact with the conductor 12 along the X-axis over a predetermined range R of the flat wire 10. . Note that the tip of the curved blade 92a is inclined at 30° with respect to the Z axis on both sides of the cutting edge. That is, the angle of the cutting edge is about 60°.

By pressing such a curved blade 92a against the conductor 12 of the flat wire 10, the conductor 12 is plastically deformed. This plastic deformation is transmitted to the left and right along the Y-axis from the location where the curved blade 92a is pressed, thereby moving the position of the ridge line 18 to the position of the ridge line 18a shown in FIG. 9(b). That is, the same machining as the moving machining of the corner explained with reference to FIG. 4A can be performed.

Similarly, on the back side of the flat wire 10, the corner can be moved by pressing the curved blade 92b formed at the tip of the mold 90b. Here, the molds 90a and 90b are examples of the second mold in the present disclosure. Furthermore, the curved blades 92a and 92b are examples of abutting portions in the present disclosure.

(Operations and effects of the modified example of this embodiment)
As explained above, in the method for peeling an insulating coating of a flat wire according to the modification of the present embodiment, the corner moving step includes two opposing sides (long sides 14a) of the flat wire 10 over a predetermined range R. Press molds 90a and 90b (second molds) having curved blades 92a and 92b (abutting portions) whose cross-sectional area is smaller toward the tip along the length direction of the rectangular wire 10, respectively, approximately at the center of each of the flat wires 10. guess. Therefore, by plastically deforming the area including the corner of the rectangular wire 10, it can be moved outward. Thereby, when the insulation coating 13 along the short side 14b is peeled off in a later step, the insulation coating 13 can be peeled off without remaining. Further, since processing is performed with the curved blades 92a and 92b instead of the cutting blade, the life of the blades can be extended.

Although the embodiments of the present invention have been described above, the embodiments described above are presented as examples and are not intended to limit the scope of the present invention. This novel embodiment can be implemented in various other forms. Furthermore, various omissions, substitutions, and changes can be made without departing from the gist of the invention. Further, this embodiment is included within the scope and gist of the invention, and is also included within the scope of the invention described in the claims and its equivalents.

10 Flat wire 12 Conductor 13 Insulating coating 14a Long side 14b Short side 15a Top and bottom surfaces 15b Left and right surfaces 15c Tip surface 16a, 16b, 16c Chamfered portion 18, 18a Ridge line 20a, 20b Hollow 30a, 30b, 60a, 60b Cutting blade 33, 63 Pad 34, 64 Lower mold 40a, 40b, 44a mold (first mold)
42a, 42b, 43a, 43b, 46a, 47a Curved blade (abutment part)
50a, 50b mold 52a, 53a, 52b, 53b curved blade 70a, 70b mold 72a, 72b curved blade 80 cutting blade 80a, 80b, 80c, 80d inclined part 90a, 90b mold (second mold)
92a, 92b Curved blade (abutment part)
R Predetermined range

Claims (3)

A first peeling step of peeling off the insulating coating on two opposing sides of the rectangular wire over a predetermined range along the length of the rectangular wire;
a corner moving step of moving the positions of the ridge lines formed by both end points of the two sides along the length direction of the rectangular wire outward over the predetermined range;
a chamfering step of forming a chamfered portion at a corner including the ridge line that has been moved outward over the predetermined range;
a second peeling step of peeling off the insulating coating on two sides of the rectangular wire perpendicular to the two sides over the specified range. The corner moving step includes:
A first mold including abutment portions having a cross-sectional area smaller toward the tip along the length direction of the rectangular wire in the vicinity of the ridge lines on two opposing sides of the rectangular wire over the predetermined range; press against
The method for peeling an insulating coating from a rectangular wire according to claim 1. The corner moving step includes:
A second mold including an abutting portion having a cross-sectional area smaller toward the tip along the length direction of the rectangular wire at substantially the center of each of two opposing sides of the rectangular wire over the predetermined range; press against
The method for peeling an insulating coating from a rectangular wire according to claim 1.

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