JPH0265648A - Pm type stepping motor - Google Patents

Abstract

PURPOSE:To improve accuracy in assembly by forming a small projected section and a recessed section to a projected section projected from a notched section provided to a flange section of two bobbins wound around with coils and by bringing coil winding pins bedded out to the recessed section into contact with a printed board. CONSTITUTION:Two bobbins 4 around which coils 7 are wound and which are fixed to stator yokes 8 are arranged in the axial direction of a rotation and clamped with fixing plates 9 and 10 to form a stator. From notches 11 arranged to bobbins 4 and yokes 8 pin-fitting projected sections 31 are projected. Small projected sections 33 and recessed sections 32 are formed to the projected sections 31 side by side up and sown and right and left. Pins 6 are bedded out to four recessed sections 32, around which the ends 7a of the coils 7 are wound and soldered. The small projected sections 33 are brought into contact with a printed wiring board 13 outside a motor frame 3. Pins 6 are fitted into connecting holes 14 of the printed wiring board 13 and soldered to connect to a wiring pattern 15. The accuracy of assembly can thereby be improved and the disconnection of coil ends is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a PM (permanent magnet) type stepping motor with an improved connection structure between a coil end and external wiring.

[Conventional technology]

For example, a stepping motor that moves a feeder such as a write/read head that is moved in the radial direction of a rotating floppy disk has a PM type step that has a lead screw that moves the feeder on the motor shaft. A motor is used, the configuration of which is shown in FIGS. 9 to 13.

The stator indicated by reference numeral 1 in FIGS. 9 and 10 is formed by housing a pair of coil assemblies 2 of the same structure in a motor frame 3. As shown in FIG.

As shown in FIGS. 9 to 11, each coil assembly 2 includes a bobbin 4 made of synthetic resin with flanges 4b provided at both ends of a cylindrical body 4a, and an outer peripheral surface of one flange 4b. A conductive bottle 6 is press-fitted to protrude from the distal end surface of a bottle mounting convex portion 5 that is integrally formed and projects in the radial direction, and a coil end 7a is wrapped around the body 4a and fixed to the bottle 6. It is formed with a coil 7.

The motor frame 3 includes, for example, a pair of first magnetic metal plates.
It is formed by butting the open ends of the stator yokes 8 together and welding that part together. and,
One first stator yoke 8 is formed by bending comb teeth as magnetic poles on the inner peripheral edge of the end surface to which the motor mounting plate 9 is fixed, and the other first stator yoke 8 also has a motor frame end plate 10. It is formed by bending comb teeth as magnetic poles on the inner peripheral edge of a fixed end face.

Furthermore, notches 11 are formed in the outer circumferential surface of each stator yoke 8 used as a motor frame portion, and these notches 11 are continuous with each other as shown in FIG. 10. . Second stator yokes 12 are respectively assembled in these first stator yokes 8 . The second stator yoke 12 is made of a magnetic metal plate, and is formed by bending comb teeth as magnetic poles inserted between the comb teeth of the first stator yoke 8 on its inner peripheral edge.

The pair of coil assemblies 2 are housed in the motor frame 3 with one flange portion a provided with the bottle attachment convex portion 5 superimposed on each other. Each coil assembly 2 is held between the stator yokes 8 and 12, and its inner peripheral surface is covered with the comb teeth. The overlapping pin mounting convex portions 5 of each coil assembly 2 have notches 1 as shown in FIGS. 9 and 11.
1 is passed.

Outside the motor frame 3, the bottle 6 is passed through a connection hole 14 provided in the printed wiring board 13.
The wiring pattern 15 of this board 13 and the bottle 6 are connected by soldering. The design requires that the back surface of the printed wiring board 13 be brought into contact with the tip end surface of the bottle attachment protrusion 5, and an external lead wire (not shown) is connected to the wiring pattern 15.

The motor mounting plate 9 is screwed to a fixing member (not shown), and a sliding bearing 16 made of a sintered alloy is mounted at the center thereof. A bearing means is provided on the fixed member so as to face the sliding bearing 16. Furthermore, a preload spring portion 17 is provided at the center of the motor frame end plate 10, which is cut and raised on the inner surface thereof.

Further, the motor shaft indicated by the reference numeral 18 in FIG. 9 passes through the sliding bearing 16 at its intermediate portion and is rotatably supported. Along with this, a steel ball 19 fixed to one end of the motor shaft 8 is brought into contact with the preload spring part 17, and a steel ball (not shown) fixed to the other end of the motor shaft is pressed against the bearing means by the biasing force of the preload spring part 17. As a result, the motor shaft 18 is rotatably provided while being restrained from moving in the axial direction.

A cylindrical rotor magnet 21 is attached to one end of the motor shaft 18 with a molded resin layer 20 interposed therebetween. The rotor magnet 2] is magnetized with multiple poles alternately along the circumferential direction, and its outer peripheral surface faces the pole teeth of each stator yoke 8, 12 with a slight air gap. Note that the motor shaft 18 with steel balls fixed to both ends, the molded resin layer 20, and the rotor magnet 21 form a rotor.

Furthermore, a portion of a lead screw (not shown) is formed at the other end of the motor shaft 18. A movable body (not shown) is screwed into a portion of this screw with its rotation restricted, and an A-shaped body such as a read/write head is supported on the movable body. Therefore, as the rotor rotates, a portion of the lead screw can move the movable body along the axial direction of the motor shaft 18.

[Problem that the invention attempts to solve]

According to the conventional structure described in "-", if the coil end 7a part wound around the bottle 6 is gathered together to form a ball larger than the connection hole 14, that part acts as a stopper and the 12th As shown in the figure, the printed wiring board 13 is separated from the tip surface of the bottle attachment projection 5, and the printed wiring board 1
There was a problem that 3 was out of the management standard position. Furthermore, as the printed wiring board 13 is pushed in the direction of the arrow in FIG. 13 and is brought into contact with the tip surface of the pin attachment projection 5, the coil end 7a is moved as shown in FIG.
The tip side of the coil end 7a is tied to the pin 6, so that the coil end 7a is in a tense state and is facing the pin 6.
Since the hole edge 14a of the connection hole 14 shown in FIG. 13 hits, there is a problem in that the coil end 7a may be disconnected.

Further, in the conventional configuration, the printed wiring board 13 is connected to the pin 6 by soldering, but the pin 6 is simply attached to the pin attachment convex portion 5 by press fitting. Therefore, when a strong external force is applied to the printed wiring board 13 in the direction of arrow B in FIG. there were.

Moreover, in the conventional configuration, no means is taken to regulate the positions of the pin attachment protrusions 5 of the pair of coil assemblies 2 that are overlapped with each other. Due to the play based on the dimensional difference, the pin attachment protrusions 5 move individually, and the positional relationship of the pins 6 protruding from these parts is not maintained constant. As a result, the positional relationship between these pins 6 and the connection holes 14 of the printed wiring board 13 may be distorted, and there is a problem that the work of attaching the printed wiring board 13 to the pins 6 becomes troublesome.

The present invention makes it possible to reliably mount the printed wiring board within the control standard position, prevent disconnection of the coil end, and prevent the printed wiring board from being accidentally removed. The purpose of this invention is to obtain a PM type stepping motor that can improve the workability of mounting a board.

[Means for Solving the Problems] The present invention provides a bobbin in which flanges are provided at both ends of a cylindrical body, and a pin mounting convex portion formed to protrude in the radial direction on the outer surface of one of the flange portions. a conductive pin protruding from the body, and a coil wound around the body and having a coil end wound around and fixed to the bottle, the one flange portion provided with the pin mounting convex portion being connected to the other flange portion. A pair of coil assemblies are provided on top of each other, and the pair of coil assemblies are housed in a motor frame, and the pin mounting convex portion is passed through a notch formed in the frame, and printed outside the motor frame. This pin is applied to a PM type stepping motor in which the pin is passed through a connection hole provided in a wiring board and the wiring pattern of the board is soldered to the pin.

In the PM type stepping motor of the present invention, the printed wiring board can be reliably installed within the control standard position, and in order to prevent disconnection of the coil end,
A concave portion and a small convex portion adjacent to each other are formed on the tip side of the pin attachment convex portion, the pin is provided protruding from the bottom surface of the concave portion, and the printed wiring board is abutted against the tip surface of the small convex portion. It is something that

In addition, in order to prevent the printed wiring board from coming off easily, opposing locking claws are provided on one side of each of the pin mounting protrusions with the flanges on one side overlapped. It is preferable that the two end portions of the printed wiring board be locked with these locking claws.

Furthermore, in order to improve the workability of attaching the printed wiring board to the bottle, it is preferable that the overlapping surfaces of the respective bottle attachment convex portions be formed into uneven surfaces, and these uneven surfaces are fitted into each other.

[Effect]

In the PM type stepping motor configured as described above, the four parts formed at the tip side of the pin mounting convex part house the coil end wound around the bottle protruding from the bottom surface, and the S The tip of the convex portion is placed against the back side of the printed wiring board to prevent the printed wiring board from entering the recessed portion.
The mounting position of this board is regulated.

In addition, the locking claws protruding from one side of each bottle mounting convex are engaged with both ends of the printed wiring board, and the board is brought into contact with the tip surface of the small convex part of the bottle mounting convex. hold in state.

Furthermore, the overlapping surfaces of the concave and convex surfaces of the respective bottle mounting convex portions are fitted together to position the respective bottle attaching convex portions relative to each other, and to determine the mutual positional relationship of the bottles protruding from the tip surfaces of these bottle attaching convex portions. Hold in place.

〔Example〕

A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. In the description, the same configurations as those of the conventional example explained with reference to FIGS. 9 to 13 will be given the same reference numerals as those of the conventional example, and the explanation thereof will be omitted, and only the different configurations will be explained below. do.

This embodiment differs from the conventional example in the connection structure between the coil end and external wiring. That is, the bottle attachment convex portion 31, which is integrally molded with the bobbin 4 and passes through the notch 11 of the motor frame 3, has four adjacent portions 32 and a small convex portion 33 integrally formed at its distal end portion. There is. A pin 6 is press-fitted and protrudes from the bottom of the recess 32, and a coil end 7a is wound around the pin 6, and the coil end 7a is housed in the recess 32. Also, as before, outside the motor frame 3,
The bottle 6 is passed through a connection hole 14 provided in a printed wiring board 13, and is connected to a wiring pattern 15 on this board 13.
is connected by soldering. The back surface of the printed wiring board 13 is abutted against the tip end surface of the small convex portion 33.

In assembling a PM type stepping motor with such a configuration, the coil end 7a of the coil 7 is entangled at the root portion of the bottle 6 that protrudes from the bottle mounting convex portion 31, that is, at the portion located within the recess 32. can be lost. After this, the pins 6 are inserted into the connection holes 14 of the printed wiring board 13, and the back side of the board 13 is inserted into the small protrusions 3.
Push it in until it touches the tip of 3. Thereby, the printed wiring board 13 can be positioned using the small convex portion 33.

Then, while maintaining this state, the bottle 6 and the wiring pattern 15 of the printed wiring board 13 are connected by soldering.

Therefore, as described above, the position of the printed wiring board 13 is regulated by the small convex part 33, and the printed wiring board 13 is placed in the concave part 3.
2, the coil end 7a wrapped around the bin 6 in the four parts 32 will not cause variations in the mounting position of the printed wiring board 13. Therefore, the printed wiring board 13 can be accurately mounted within the control standard position, and the quality of the motor can be improved.

In addition, as mentioned above, the printed wiring board 13 does not reach into the recess 32 due to the slow action of the small convex portion 33.
Hole edge 14a of connection hole 14 of printed wiring board 13
will no longer come into contact with the coil end 7a. Therefore, disconnection of the coil end 7a can be avoided.

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6.

In this embodiment, a locking pawl 35 is integrally provided on the right side of the bottle attachment convex portion 31 disposed on the upper side in FIG. 36 is formed. Furthermore, a similar locking pawl 35 is integrally provided on the left side of the bottle attachment convex portion 31 located on the lower side in FIG. 36 is formed.

Each engaging W pawl 35 can be flexibly deformed due to the elasticity of the molded resin of the bobbin 4, and faces left and right. In addition,
A pair of coil assemblies 2 having the same structure are stacked one on top of the other with one of them reversed, so that the locking claws 35 are provided in the χ·1 direction in a point symmetrical arrangement as described above. .

Grooves 36 are formed at both ends of the printed wiring board 13. Further, the configuration other than the points explained above is the same as the configuration of the first embodiment, so the explanation thereof will be omitted.

Therefore, in addition to having the same functions and effects as the first embodiment, this second embodiment can also hold the printed wiring board 13 in a predetermined mounting position using the pair of locking claws 35. When an external force C is applied, the locking pawl 35 can receive the external force C, and the concentration of the external force on the bottle 6 can be eliminated. Therefore, it is possible to prevent the printed wiring board 13 from being accidentally removed together with the bottle 6 due to the external force C. In this second embodiment, the locking pawl 35 may be provided protruding from the other side facing the recess 32.

Further, in the third embodiment of the present invention shown in FIGS. 7 and 8, the overlapping surfaces of the respective pin attachment convex portions 31 are formed with uneven surfaces as shown in FIG. are fitted into each other as shown in FIG. Moreover, a four part 32 is provided at the tip of the convex side of the fitting, that is, the part where the wall thickness is increased due to the provision of the uneven surface, and the bottle 6 is protruded therefrom. Further, the configuration other than the points explained above is the same as the configuration of the first embodiment, so the explanation thereof will be omitted.

In addition to having the same functions and effects as the first embodiment, the third embodiment also determines the mutual positional relationship of the overlapping bottle attachment protrusions 31 by fitting the concave and convex surfaces. Therefore, even if the width of the notch 11 and the width E of the bottle attachment convex portion 31 vary slightly, the respective bottle attachment convex portions 31 will not be misaligned due to this influence, and these bottle attachment convex portions 31 The positional relationship of the four protruding bottles 6 can be maintained constant. In other words, the positional relationship between these bottles 6 and the connection holes 14 of the printed wiring board 13 may be incorrect.
Since the inconvenience of the bottle 6 not fitting into the connection hole 14 of the printed wiring board 13 can be prevented, the printed wiring board 13
The installation work can be made easier. Moreover, since the wall pressure is thicker in the part where the bottle 6 protrudes, there is no possibility that the bottle mounting convex portion 31 will be deformed by the heat generated when the bottle 6 and the printed wiring board 13 are soldered. can.

Although each of the above embodiments is configured as described above, the present invention is not limited to these embodiments. For example, the technical idea of the third embodiment may be adopted in the second embodiment. Further, the motor frame may have a single cylindrical shape whose open end is closed with a motor mounting plate (in addition,
In this case, the first and second stator yokes both have the same configuration as the second stator yoke 12, and are provided to sandwich the coil assembly housed in the motor frame. ). In addition, although the printed wiring board 13 used in each of the above embodiments is a board-like one in which the wiring pattern 15 is provided on a hard resin board, a board-like one in which the wiring pattern 15 is provided on a flexible resin board is used instead. A so-called flexible printed wiring board may also be used. When this board is employed, external lead wires can be omitted and the number of soldering points can be reduced, thereby reducing the incidence of electrical connection failures. It goes without saying that the present invention can also be applied to PM type stepping motors used for purposes other than head driving.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

In the PM type stepping motor according to claim 1, four adjacent parts and a small convex part are formed on the tip side of the bottle mounting convex part, and the bottle is protruded from the bottom of the concave part, and a small convex part is formed on the tip side of the small convex part. Since the printed wiring board is abutted, the printed wiring board can be reliably installed within the control standard position, and disconnection of the coil end can be prevented.

Further, in the stepping motor of claim 2, opposing locking pawls are provided on one side of each bottle mounting convex portion, with the flanges overlapped, respectively, and these locking pawls are provided. Since both ends of the printed wiring board are locked,
It is possible to prevent the printed wiring board from being accidentally removed.

Furthermore, in the PM type stepping motor of claim 3, the overlapping surfaces of the respective bottle mounting convex portions are formed into uneven surfaces, and these uneven surfaces are fitted to each other, so that the workability of attaching the printed wiring board to the bottle is improved. Direction-L is possible.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is an exploded perspective view of the main parts, FIG. 2 is a vertical sectional view of the whole, FIG. 3 is a perspective view of the coil assembly, FIG. 4 is a plan view showing a part of the main part in section. 5 and 6 show a second embodiment of the present invention, FIG. 5 is an exploded perspective view of the main parts, and FIG.
The figure is a plan view of the main parts. 7 and 8 show a third embodiment of the present invention, FIG. 7 is a perspective view of the coil assembly, and FIG. 8 is a front view of the main parts. Figures 9 to 13 show a conventional example, Figure M9 is a longitudinal sectional view of the whole, Figure 10 is a partially exploded perspective view, Figure 11 is a perspective view of the coil assembly, Figures 12 and 13. FIG. 3 is a partially sectional plan view illustrating different examples of poor attachment of printed wiring boards. 2... Coil assembly, 3... Motor frame, 4... Bobbin, 4a... Body, 4b... Flange part, 6... Bin, 7... Coil, 7a... Coil end, 11... Notch, 13... Printed wiring board, 14... Connection hole, 15... Wiring pattern, 31
... Bottle mounting convex portion, 32... Four parts, 33... Small convex portion, 35... Locking claw. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 10 Section C

Claims (3)

[Claims] (1) A bobbin with flanges provided at both ends of a cylindrical body, a conductive pin protruding from a pin mounting convex formed on the outer surface of one of the flange parts, and protruding in the radial direction; A pair of coil assemblies are provided, each of which has a coil that is wound around a body portion and has a coil end that is wound and fixed to the pin, and is provided by overlapping one of the flange portions provided with the pin mounting convex portion. , these pair of coil assemblies are housed in a motor frame, and the pin mounting protrusion is passed through a notch formed in the frame, and the pin is passed through a connection hole provided in a printed wiring board outside the motor frame. , in a PM type stepping motor in which the wiring pattern of this board and the above-mentioned pin are soldered, a concave part and a small convex part adjacent to each other are formed on the tip side of the above-mentioned pin attachment convex part, and the above-mentioned pin is protruded from the bottom surface of the concave part. A PM type stepping motor characterized in that the printed wiring board is abutted against the tip end face of the small convex portion. (2) Opposing locking claws are provided on one side of each of the pin mounting protrusions with the one flange portion overlapped with each other, and the printed wiring board is attached to these locking claws. 2. The PM type stepping motor according to claim 1, wherein both ends are locked. (3) The PM type stepping motor according to claim 1 or 2, wherein the overlapping surfaces of the respective pin mounting convex portions are formed into uneven surfaces, and these uneven surfaces are fitted into each other.