EP0461562A1

EP0461562A1 - Deflection coil and manufacturing method therefor

Info

Publication number: EP0461562A1
Application number: EP91109384A
Authority: EP
Inventors: Hiroshi Kawazoe; Toshiichi Murakoshi; Toshihiro Takahata; Ryoichi Ueno; Takuji Kamata
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1990-06-12
Filing date: 1991-06-07
Publication date: 1991-12-18
Also published as: JPH0447634A; KR920001597A

Abstract

A deflection coil includes a bobbin (10) made of insulating material and having a coil guide portion (10a), and a coil assembly (40) made by winding a coil wire (20) around the coil guide portion and fixing the coil wire to the coil guide portion. In a manufacturing method for such a deflection coil, the coil wire is wound around the coil guide portion by repeating the operation including moving a coil wire supply member (50) from the bobbin front end to the rear end, turning the bobbin by a predetermined angle, returning the supply member to the front end, and reversely turning the bobbin by the same angle as the predetermined angle.

Description

BACKGROUND OF THE INVENTION

The present invention generally relates to a deflection coil and a manufacturing method therefor, and more particularly, to a deflection coil for generating magnetic field in a television set or the like, and a manufacturing method for the deflection coil.
A deflection coil for the television set or the like is required to be installed tightly along the outer surface of an image receiving tube. Accordingly, there has been conventionally used a deflection coil in which on the outer surface of a hopper-shaped core member made of insulating material and corresponding to the outer shape of the image receiving tube, a coil assembly-forming member formed in a three-dimensional curved shape corresponding to the outer surface of the core member in a separate manufacturing process is integrally joined thereto.
However, in the above-mentioned conventional method for manufacturing a deflection coil, a complicated process of making separately the coil assembly-forming member of a complicated curved surface shape and the core member and joining integrally with each other is necessary, which results in such an issue that the productivity is poor and the deflection coil thus manufacture is poor in quality and performance.
When the coil assembly-forming member does not tightly contact the outer surface of the core member, it is impossible to favorably generate the magnetic performance, and when there is a local gap between the coil assembly-forming member and the core member, the magnetic performance at that particular portion is lowered, resulting in the deterioration of the magnetic performance on the whole or unevenness in the quality and performance thereof. However, as described above, it is extremely difficult to integrally join the preliminarily separately manufactured coil assembly-forming member and core member so as to tightly contact each other. Accordingly, the assembly operation takes time, and clearances between the coil assembly-forming member and the core member and unevenness in the tightness of the contact tend to take place by conventional means.
Furthermore, although the coil assembly-forming member is required to be assembled together with the core member so as to be joined together after being formed into a thin three-dimensional curved shape, it is extremely difficult to deal with this coil assembly-forming member without any deformation. Accordingly, the assembly and joining operation for the coil assembly-forming member and the core member becomes further troublesome, when the coil assembly-forming member is once deformed during handling, it becomes impossible to bring the coil assembly-forming member into tight contact with the core member.

SUMMARY OF THE INVENTION

Accordingly, an essential aspect of the present invention is to provide a deflection coil in which an assembly and joining process between a coil assembly-forming member and a core member is eliminated so as to improve the productivity thereof, and tight contact is achieved therebetween so as to improve the quality and performance thereof, and to provide a manufacturing method for such a deflection coil.
In accomplishing these and other objects, according to one aspect of the present invention, there is provided a deflection coil comprising:
a bobbin made of insulating material and having a coil guide portion; and
a coil assembly made by winding a coil wire around the coil guide portion and fixing the coil wire to the coil guide portion.
According to another aspect of the present invention, there is provided the deflection coil, wherein the bobbin is of an approximately trumpet shape and has a neck portion and a skirt portion, and the coil guide portion is provided on the neck portion of the bobbin, and the deflection coil further comprises:
a circumferential groove, provided on the skirt portion of the bobbin, for winding the coil wire;
an outward bent projection provided on the neck portion of the bobbin and preventing the coil wire wound around the coil guide portion from taking off from the coil guide portion; and
a notch provided on the neck portion of the bobbin and engaged the coil wire therein so as to wind the coil wire around the coil guide portion.
According to a further aspect of the present invention, there is provided a manufacturing method for a deflection coil, comprising the steps of:
winding a coil wire, with respect to a bobbin made of insulating material and having a coil guide portion, from a front side to a rear side on a first inner side of the bobbin, by inserting a coil wire supply member arranged to forward the coil wire from a tip end of the supply member into the bobbin;
winding the coil wire around an outer surface at the rear side of the bobbin by turning the bobbin by a predetermined angle in a state where the coil wire is engaged with an outer circumference of the bobbin, with the coil wire held by the supply member being held by a chucking mechanism on the rear side of the bobbin;
winding the coil wire from the rear side on a second inner surface of the bobbin to the front side thereof by releasing holding of the coil wire with the chucking mechanism and returning the supply member to the front side; and
winding the coil wire around the outer surface on the front side of the bobbin by turning the bobbin by the same angle as the predetermined angle in a reverse direction in a state where the tip end of the supply member is positioned on the outer circumferential of the bobbin,
the manufacturing method being arranged to repeat the steps so as to wind the coil wire along the coil guide portion and fix thereto, thus to form a coil assembly.
According to the above constructions of the present invention, by winding and fixing the coil wire along the coil guide portion, a vortex-shaped coil assembly fixed to a bobbin in the state where the coil wire is formed in a predetermined three-dimensional curved shape, and brought tightly into contact with the three-dimensional shape of the bobbin may be formed, and thus, a deflection coil provided with the coil assembly may be obtained. Therefore, when the deflection coil, that is, a bobbin provided with a coil assembly is installed, as it is, on a predetermined installation position of a television set or the like, it can be installed in tight contact with the outer shape of the television receiving tube, etc., a favorable magnetic performance as a deflection coil may be generated.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings throughout which like parts are designated by like reference numerals, and in which:

Fig. 1 is a perspective view of a deflection coil according to one preferred embodiment of the present invention;
Fig. 2 is a sectional view of the neck portion of the deflection coil in Fig. 1;
Fig. 3 is a perspective view of a bobbin of the deflection coil;
Figs. 4 to 8 are views showing the deflection coil manufacturing processes stepwise, in which Figs. 4 to 6, and Figs. 7A and 8A are respectively perspective views, while Figs. 7B and 8B are views showing the arrangement of coil wires;
Fig. 9 is a perspective view of the formed coil; and
Fig. 10 is a perspective view of a manufacturing apparatus for the deflection coil.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figs. 1 and 2 show a deflection coil according to one preferred embodiment of the present invention.
Fig. 3 shows a whole shape of a bobbin 10, which is basically similar, in material and overall shape, to a core member employed for joining coil assembly-forming member in a conventional deflection coil. Namely, as a material for the bobbin 10, various synthetic resins and other materials the same as those employed as insulating materials in the usual electric apparatus are used. The overall shape of the bobbin 10 is approximately of a trumpet shape adapted to the outer surface shape of the installation position of the television receiving tube where the deflection coil is to be installed.
The bobbin 10 is provided with a coil guide portion 10a where coil wires 20 are to be wound therearound and fixed thereto. As the coil guide portion 10a, grooves or recesses wherein the coil wires 20 may be inserted or protruding stripes or projections restricting the movement of the coil wires 20 may be provided continuously or intermittently along the path for winding the coil wires 20. As a concrete construction of the coil guide portion, for example, as shown in Figs. 1 and 3, a circumferential groove 32 is provided on the skirt portion of the bobbin 10, and outward bent projections 34 and a plurality of notches 36 are provided on the top portion of the bobbin 10, with a plurality of guide grooves 38 being provided on the inner surface of the bobbin 10 as shown in Fig. 2 so as to extend from the circumferential groove 32 to the notches 36. The guide grooves 38 are connected, at the bottom surface on the bobbin skirt side, to respective notches 39 formed on the side wall of the circumferential groove 32.
Each of the coil wire 20 is made of a conductive material the same as employed for the conventional deflection coil and wound in a vortex shape along the coil guide portion 10a. The coil wires 20 wound around the coil guide portion 10a are fixed at the coil guide portion 10a so as not to be moved, and thus, plural sets of coil sub-assemblies 40a and 40b, each of which is of an approximately trapezoidal shape, are arranged on two positions confronting each other. The winding position for the coil wire 20, that is, the arrangement form of a coil assembly 40 including the sub-assemblies 40a and 40b may be set, as in the conventional deflection coil, so that magnetic performance may be favorably generated, and the guide portion 10a is provided in correspondence to the arrangement form of the coil assembly 40 to be desired.
Subsequently, a method of forming the coil assembly 40 through winding and fixing the coil wire 20 onto the bobbin 10 is shown stepwise in Figs. 4 to 8. In Figs. 4 to 8, two coil sub-assemblies 40a and 40b are simultaneously formed by winding two coil wires 20a and 20b simultaneously onto two confronting portions of the bobbin 10.
As shown in Fig. 4, the coil wires 20a and 20b are held by supply nozzles 50. The supply nozzle 50 is arranged to continuously supply the coil wire 20 from its tip end. The supply nozzles 50 are inserted into the central space of the bobbin 10 from the skirt portion on the front side of the bobbin 10 so as to be projected from the top of the bobbin 10 on the rear side of the bobbin 10. Such an operation of the supply nozzle 50 can be easily effected by a cam mechanism, link mechanism, or other usual operation mechanism. The coil wires 20a and 20b are respectively arranged along the guide grooves 38 provided on the inner surface of the bobbin 10 and the ends thereof extend outward of the bobbin 10 through the notches 39.
As shown in Fig. 5, by holding the coil wires 20a and 20b at portions projecting from the top end of the bobbin 10 with a chucking mechanism 60, each of the coil wires 20a and 20b is engaged with one of the notches 36 on the top end of the bobbin 10 and part thereof is drawn outside of the bobbin 10. As the chucking mechanism 60, a mechanism similar to the chuck open/close mechanism, shift mechanism employed in the usual wire handling apparatus or the like may be used.
As shown in Fig. 6, when the bobbin 10 is turned by a predetermined angle, since the coil wires 20a and 20b are engaged with the notches 36, the coil wires 20a and 20b are turned in an arcuate shape along the top periphery of the bobbin 10. In this case, since the bent projections 34 are provided on the top end portion of the bobbin 10, the coil wires 20a and 20b do not drop out of the top end thereof. It is to be noted here that the coil wires 20a and 20b inserted into the guide grooves 38 on the inner surface thereof are moved so as to be replaced in position by each other.
As shown in Fig. 7A, by releasing the holding of coil wires 20a and 20b by the chucking mechanism 60, the supply nozzle 50 is withdrawn into the bobbin 10 so as to be pulled out to the outside of the bobbin skirt portion. Furthermore, when the supply nozzle 50 is withdrawn into the bobbin 10, the coil wires 20a and 20b wound around the neck portion of the bobbin 10 are engaged with the notches 36 so as to be wound along the guide grooves 38 on the bobbin inner surface up to the skirt portion of the bobbin 10. In other words, as shown in Fig. 7B, the coil wires 20a and 20b are arranged respectively in a semicircular form at the neck portion of the bobbin 10, and from thereon in an approximately hopper shaped form expanding toward the skirt portion.
As shown in Fig. 8A, the bobbin 10 is turned by the same angle in the reverse direction, whereby the ends of the coil wires 20a and 20b arranged along the guide grooves 38 on the bobbin inner surface are turned around along the circumferential groove 32. Namely, as shown in Fig. 8B, the coil wires 20a and 20b are respectively in a three-dimensional trapezoidal form along the bobbin 10.
When the above-described processes shown in Figs. 4 through 8 are repeated, coil sub-assemblies 40a and 40b wherein a plurality of coil wires 20a and 20b are bundled in a vortex shape are formed.
When the processes are repeated by consecutively changing the positions of the guide grooves 38 and the notches 39 of the bobbin 10 wherein the coil wires 20a and 20b are to be arranged, the coil assembly 40 wherein a plurality of approximately trapezoidal shaped portions are combined together can be formed on the bobbin 10. It is to be noted here that the depth of the notches 36 provided on the bobbin top end are arranged to vary in length stepwise, whereby the coil wire 20 engaged into respective notches 36 and turned around the bobbin neck portion may be arranged stepwise side by side in the axial direction of the bobbin 10. Furthermore, although not shown, the end portion of the coil wire 20 is pulled out of the coil assembly 40, and connected properly to a magnetic excitation circuit when the deflection coil is to be used.
Fig. 10 shows a schematic construction of a manufacturing apparatus employed for executing such a manufacturing method as described above, which apparatus includes a reel stand 22 for accommodating the coil wire 20, a bobbin turning mechanism 80 for holding the bobbin 10 so as to turn the same, the supply nozzle 50 for holding the coil wire 20 at the central portion of the bobbin turning mechanism 80, and the chucking mechanism 60 arranged on the front side of the bobbin turning mechanism 80.
The bobbin 10 on which the coil assembly 40 is formed in the manner as described above, that is, the deflection coil is installed as it is on the installation position of a television receiving tube or the like. In other words, the bobbin 10 performs the same function as a core member in the conventional deflection coil. To this end, the bobbin 10 is provided a construction or mechanism portion necessary for installation onto the television receiving tube.
It is to be noted here that the shape and arrangement of the bobbin or coil assembly may be changed at will, besides the embodiment described above. Furthermore, as a means for winding a coil wire around the bobbin and fixing the same thereto, besides the method of using the supply nozzle 50 and the chucking mechanism 60 as described in the foregoing embodiment, various wire handing mechanisms may be used in combination.
As is clear from the foregoing description, since the deflection coil and the manufacturing method therefor according to the present invention is so arranged that without manufacturing a coil assembly-forming member for assembly and joining with a core member, a coil assembly is formed by winding coil wires directly around a bobbin and the bobbin is installed, as it is, on a television receiving tube or the like, the assembly and joining process between a coil assembly-forming member and a core member which has been so far extremely troublesome can be eliminated, and thus, it becomes unnecessary to handle a coil assembly-forming member of a thin and complicated curved shape. As a result, the construction of the deflection coil may be simplified, with a consequence of an improvement of productivity.
Furthermore, since coil wires are directly wound around a bobbin, the bobbin and coil wires, that is, the coil assembly become into positive contact with each other so as to be arranged without any clearance therebetween. Accordingly, such a possibility that there arise any clearances between the coil assembly-forming member and the core member as in the conventional deflection coil is removed, and a deflection coil of an improved magnetic performance and a stable quality and performance may be obtained.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

Claims

A deflection coil comprising:
a bobbin (10) made of insulating material and having a coil guide portion (10a); and
a coil assembly (40) made by winding a coil wire (20) around the coil guide portion and fixing the coil wire to the coil guide portion.
The deflection coil as claimed in claim 1, wherein the bobbin (10) is of an approximately trumpet shape and has a neck portion and a skirt portion, and the coil guide portion (10a) is provided on the neck portion of the bobbin, and the deflection coil further comprises:
a circumferential groove (32), provided on the skirt portion of the bobbin, for winding the coil wire (20);
an outward bent projection (34) provided on the neck portion of the bobbin and preventing the coil wire (20) wound around the coil guide portion (10a) from taking off from the coil guide portion (10a); and
a notch (36) provided on the neck portion of the bobbin and engaged the coil wire (20) therein so as to wind the coil wire (20) around the coil guide portion (10a).
A manufacturing method for a deflection coil, comprising the steps of:
winding a coil wire (20), with respect to a bobbin (10) made of insulating material and having a coil guide portion (10a), from a front side to a rear side on a first inner side of the bobbin, by inserting a coil wire supply member (50) arranged to forward the coil wire (20) from a tip end of the supply member into the bobbin;
winding the coil wire (20) around an outer surface at the rear side of the bobbin by turning the bobbin by a predetermined angle in a state where the coil wire (20) is engaged with an outer circumference of the bobbin, with the coil wire (20) held by the supply member (50) being held by a chucking mechanism (60) on the rear side of the bobbin;
winding the coil wire (20) from the rear side on a second inner surface of the bobbin to the front side thereof by releasing holding of the coil wire (20) with the chucking mechanism (60) and returning the supply member (50) to the front side; and
winding the coil wire (20) around the outer surface on the front side of the bobbin by turning the bobbin by the same angle as the predetermined angle in a reverse direction in a state where the tip end of the supply member (50) is positioned on the outer circumferential of the bobbin,
the manufacturing method being arranged to repeat the steps so as to wind the coil wire along the coil guide portion and fix thereto, thus to form a coil assembly.