JPH05146138A - Stepping motor - Google Patents

Abstract

PURPOSE:To align terminal pins on a straight line by fixing a spool having a plurality of protrusions formed to stand the pins in a state that pawls provided at the opposed protrusions of the spool are engaged with each other in a stepping motor in which spools of two stator coils are coaxially disposed in an axial direction. CONSTITUTION:Terminal holders 52 are formed at adjacent sidewalls of spools 48, 50. The holder 52 is formed of three protrusions 48b, 50b formed on the opposed surfaces of the spools 48, 50. Pawls (c) are respectively formed at the protrusions 48b, 50 to be able to be engaged with each other. Then, both the holders 52 are engaged fixedly by superposing the spools 48, 50 in an opposed manner. Three terminal pins 54 are stood at the respective protrusions 48b, 50b of the holders 52. Accordingly, the standing positions of the pins 54 are aligned on an extension line of the pawl (c) to be straight.

Description

TECHNICAL FIELD The present invention relates to a step motor, and more particularly to a fixed portion of a connecting wire thereof.

[Prior Art] As a conventional stepping motor, one in which two winding frames 148 and 150 are coaxially arranged in the axial direction of a rotor 128 is known (for example, Japanese Patent Laid-Open No. 61-4459). .. In such a stepping motor, the windings 148a and 150a (two windings for each winding frame) wound around the winding frames 148 and 150 as shown in FIG. 17 are processed as follows. First, the windings 148a and 150a are wound around the winding frames 148 and 150 with one ends of the windings 148a and 150a being held by the pins. Then, the final end is held by the pin, and then the windings 148a and 150a are cut.

 With regard to such a stepping motor, the present applicant has a structure shown in FIG. 18 according to the specification and the drawing attached to the application of Japanese Patent Application No. 2-42698 as the end treatment of the windings 148a and 150a. I applied for a patent. In the figure, three projecting portions 148b and 150b are provided on the opposing surfaces of the two reels 148 and 150, and the projecting portions 148b and 150b are arranged so as to overlap with each other. Terminal pins 154 are erected on the protrusions 148b and 150b, and the ends of the windings 148a and 150a are soldered to the terminal pins.

 As shown in FIG. 16 and FIG. 18, cores 136 to 142 having a large number of comb tooth-shaped magnetic poles 136a to 142a are mounted on these reels 148 and 150, and then they are coaxially arranged. Be integrated. The general-purpose socket 122 is soldered to the terminal pin 154. This general-purpose socket 122 is fixed to the motor frame.

 With the above configuration, it is possible to prevent an unreasonable tensile force from being applied to the winding wire, reduce the manual work process, and significantly improve the workability.

[Problems to be Solved by the Invention] In the step motor having the above configuration, it is desirable that the terminal pins be accurately aligned. The reason is that by arranging the terminal pins in a straight line in this way, the connection with the connector can be automated by processing such as sinking solder. However, it has been found that, in the above configuration, the terminal pins are often not aligned in a straight line with sufficient accuracy. This is because when the two reels are lined up and pressure is applied during the integration process using the hard resin, the reel is not uniform due to the non-uniformity between the wound portion and the unwound portion. Because it bends.

 Even when the socket as described above is not used, it is desirable that the terminal pins be aligned on a straight line for various reasons such as automation of processing of other terminal pins.

 The present invention has been made to solve the above problems, and an object thereof is to provide a structure of a step motor in which terminal pins are arranged in a straight line.

[Means for Solving the Problems] In order to achieve the above-mentioned object, according to the present invention, a plurality of winding frames are formed in which windings are wound and a plurality of projecting portions in which terminal pins are erected are formed. In the stepping motor, the parts are arranged alternately so that the projections are provided with claws, and the claws of the opposite winding frames are arranged so as to engage with each other. It is characterized in that it is erected at a position that is a straight line in a state where the claw portions are engaged.

[Operation] In the present invention having the above configuration, the claw portions provided on the projecting portions of the opposing winding frames are arranged so as to be caught by each other. In other words, this claw part plays a role in determining the position of each reel. Therefore, if these claws are fixed together when they are engaged, the terminal pins are aligned. At this time, it is desirable that each winding frame is slightly elastically deformed so that stress acts in a direction in which each claw portion engages when the winding frame is fixed.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

 2 to 4, a motor case 10 includes a frame 12 formed by bending a flat strip-shaped plate material into a C-shaped tube, and fixed by spot welding to both ends of the tube of the frame 12. The both end plates 14 and 16 thus formed are formed in a hollow shape.

 A metal plate 18 for holding the bearing portion 20 is attached inside the rear end plate 16, and a holding portion 18a and a disc portion 18b are integrally resin-molded on the metal plate 18. The front view is shown in FIG. The holding portion 18a has a cylindrical shape having the same peripheral shape as a housing connector 22 described later, and the housing connector 22 can be fitted therein.

Further, the disk portion 18b is provided with positioning holes 18c at four locations, and has a bearing portion 20 in the center. The metal plate 18 can be easily manufactured in one step by a process such as insert molding with the bearing portion 20 fitted in the mold.

 Also, a hard resin (PBT: polybutylene terephthalate, etc.) for integrally fixing a stator 26, which will be described later, integrally extends inside the front end plate 14, as shown in FIG. 24 are interposed. A bearing 25 is fixed to the central portion of the spacer 24. The spacers 24 and the metal plate 18 electrically separate the cores 36 and 42 and the rotor 28 in the stator 26 from the end plates 14 and 16. When the motor case 10 is assembled, both end plates 14 and 16 are pressed while the electrodes 29 are connected to the both end plates 14 and 16 as shown in FIG. By this pressurization, the small protrusions 12a provided on the frame 12 are pressed against both end plates and electrically connected. The pressing force is set so that the small projection 12a is crushed by about two thirds. Then, a voltage is applied between both electrodes, a large current flows, and spot welding is performed at the position of the small protrusion 12 a provided on the frame 12. Therefore, when the end plates 14 and 16 and the frame 12 are spot-welded, the end plates 14 and 16 and the stator 26 or the rotor 28 are inadvertently contacted with each other, and the current is shunted to obtain a necessary amount of heat. It is possible to prevent welding failure without being prevented. At the same time, it is also possible to prevent metal powder scattered during spot welding from entering between the stator 26 and the rotor 28.

 A motor shaft 30 is rotatably supported by bearings 25 and 20 at the center of both end plates 14 and 16. A rotor 28 formed of a permanent magnet 32 is integrally fixed to the motor shaft 30 by a hard resin 34 between the bearings 20 and 25 around the shaft of the motor shaft 30.

 An annular permanent magnet 32 having a large number of magnetic poles is arranged around the motor shaft 30 in the rotor 28, and a hard resin 34 is filled between the permanent magnets 32. As shown in FIG. 2, the permanent magnet 32 is provided with concentric grooves 32a on both end faces thereof, and the hard resin 34 extends to the groove portion 32a. Therefore, the deviation of the shaft center between the motor shaft 30 and the outer peripheral surface of the rotor 28, which is caused by the contraction of the hard resin 34 immediately after molding, can be minimized. For this reason, the occurrence of harmful effects such as contact between the rotor 28 and the stator 26 can be suppressed.

 Inside the motor case 10, two pairs of cores 36 to 42 each having a plurality of comb-shaped magnetic poles 46 alternately arranged along the outer circumference of the rotor 28 are fixed in the axial direction of the motor shaft 30. It is installed in. The operation of the magnetic pole 46 is publicly known (for example, FIG. 2 of Japanese Patent Laid-Open No. 63-39443), and therefore detailed description of the operation is omitted. V-shaped grooves 44 are formed on the outer periphery of the cores 36 to 42 (only the cores 36 and 38 are shown in FIG. 7). Each of the cores 36 to 42 is formed in advance so that the position of the comb-shaped magnetic pole 46 is an appropriate position when the V-shaped groove 44 is aligned. A step 46a is formed on the outer side of the tip of the comb-shaped magnetic pole 46, as shown in FIG. For example, when the thickness of the comb-shaped magnetic pole 46 is about 1.0 mm, the step 46 a has a depth of about 0.3 mm and is 0.5 mm to 0.5 mm from the tip of the comb-shaped magnetic pole 46. It is processed by press working etc. so that it becomes about 8 mm lower.

 Between the pair of cores 36, 38 and 40, 42, reels 48, 50 are respectively arranged as shown in FIG. These two reels 48, 50 have a U-shaped cross section and are formed in an annular shape so that the open ends of the U-shaped members face outward. V-shaped grooves 48a (the V-shaped groove of the winding frame 50 is not shown) having the same shape as the V-shaped groove of the core are formed on the flange portions of the winding frames 48 and 50 at two locations. Windings 48c and 50c made of two enameled wires are wound around the winding frames 48 and 50, respectively.

 An end holder 52 is formed on each side wall of the winding frames 48 and 50, which are adjacent to each other when mounted in the frame 12. The structure of this terminal holder 52 is shown in FIGS. 1 and 9. As shown in this drawing, the terminal holder 52 is composed of three projecting portions 48b and 50b provided on the facing surfaces of the winding frames 48 and 50, respectively. A claw c is provided on the right side of the protrusion 50b protruding from the lower side to the upper side of the protrusion 48b, and on the left side of the protrusion 48b protruding from the upper side to the lower side.

The claw c can be engaged with the claw c of the terminal holder 52 provided on the winding frames 48 and 50 on the other side. The above-mentioned terminal holder 52 is provided at an intermediate phase between the two V-shaped grooves 48a. Therefore, the reels 48 and 50 do not have to be resin-molded using separate molds, and one reel formed by the same mold is reversed to form a pair of reels. After the winding frames 48 and 50 are stacked in such a manner that the two end holders 52 face each other, a force is applied to press the two terminal holders 52 against each other, whereby the claws c are elastically deformed and fixedly engaged. Three terminal pins 54 are erected on each of the protrusions 48b and 50b of each terminal holder 52. The standing position of the terminal pin 54 is on the extension line of the claw c 1 (shown by the alternate long and short dash line in FIG. 9). Therefore, all the terminal pins 54 are aligned on the straight line at the engagement positions of the claws c. For this reason, when the reel is deformed in the direction in which the claws claw each other in a state in which these groups are pressed from the upper and lower directions during the integration process by the hard resin (which serves as the spacer) 24 described in detail later, The terminal pins 54 are aligned and fixed in a straight line. The spacing between the terminal pins 54 is set equal to the spacing between the connector pins of the housing connector 22.

 A hard resin (acting as the spacer) 24 is poured into the gap between the cores 36 to 42 and the winding frames 48, 50 thus assembled, and is integrally fixed. This step will be described below. In FIGS. 10 and 11, first, a set of cores 36 to 42 and reels 48 and 50 is set in the injection molding device.

At this time, the alignment of the axes of the cores 36 to 42 and the winding frames 48 and 50 is the same as the inner shape of the cores 36 to 42 formed in the injection molding apparatus. The columnar portion 58a (standing on the lower die 58). By setting the set of the cores 36 to 42, the winding frames 48 and 50, and the bearing 25. Further, as to the circumferential alignment, as shown in FIG. 11, the slide 62 is pushed so as to be positioned in the V-shaped grooves 44, 48a which are cut in advance on the circumferences of the cores 36 to 42 and the winding frames 48, 50. It is done by holding it in a disciplined state. The V-shaped grooves 44 and 48a are fitted smoothly when the slide 62 for positioning is pressed, and the respective cores 36 to 42 are slightly rotated to correct their circumferential positions. So that the angle is set.

Further, the slide 62 is normally biased inward by a belt, but is slightly retracted (about 0.1 mm to 0.2 mm) by a solenoid at the stage of setting this set. In other words, the core and the winding frame are set according to the slide 62 for temporary positioning, and then the slide 62 is biased to separate the cores 36 to 42 and the winding frames 48, 50 from each other. This position will be determined by turning. Then, in this state, the molds 58 and 64 are further pressed from above and below to be compressed from above and below. The upper mold 64 descends until it comes into contact with a stopper 58b formed integrally with the lower mold 58, and the hard resin (serving as the spacer) 24 melted in this state is poured from the injection hole 64a. Since the stopper 58b is integrally formed with the lower die 58 as described above, its positional accuracy can be sufficiently increased.

That is, by fixing the stopper 58b with the upper mold 64 in contact with the stopper 58b, it is possible to improve the dimensional accuracy in the vertical direction. By the above compression, the gap between the cores 36 to 42 and the molds 58 and 64 is crushed to form a sealing means. Due to this compression, the flange portions of the winding frames 48 and 50 are elastically deformed.

At this time, due to the non-uniformity between the wound portion and the unwound portion of the windings in the winding frames 48 and 50, a biasing force acts on the terminal holder 52 in the direction in which the claws c engage with each other. Therefore, the terminal pins are aligned.

 The hard resin (which serves as the spacer) 24 poured from the injection hole 64a flows into the gap between the members, but is blocked by this sealing means and does not overflow to the outside of the reels 48 and 50. By hardening the hard resin 24, the respective members are integrated. At this time, the stator 26 is solidified in a state where the terminal pins 54 are aligned in a straight line, and therefore the above-mentioned state is maintained even after the hard resin 24 is solidified. In addition, the lower die is formed with a recess for forming a protrusion that engages with the hole 18c of the metal plate, and the integrated stator 26 has a protrusion 24a that engages with the hole 18c. Is formed. The protrusion 18a engages with the hole 18a of the metal plate 18 as shown in FIG. 12 (a), whereby the positions of the both are aligned. The protrusion 24a is provided with an inclined portion on its inner side so that the protrusion 24a can be easily inserted into the hole 18c. Therefore, the outer sides of the protrusion 24a and the hole 18c are configured to come into contact with each other for alignment, and the inner side is provided with a slight gap. The portion of the metal plate 18 that protrudes to the right in FIG. 12 (a) through the hole 18c is as shown in FIG. 12 (b) when the end plate 16 is spot welded. The end plate 16 applies pressure and crushes it.

Therefore, even after the spot welding, the metal plate 18 and the stator 26 are firmly fixed.

 When the step 46a is not formed on the comb-shaped magnetic pole 46, when the external force such as impact is applied after molding, as shown in FIG. May occur. Generally, since the gap between the rotor 28 and the stator 26 is about 0.1 mm to 0.2 mm, there is a possibility that the two may come into contact with each other due to the above-mentioned warpage, resulting in poor rotation.

However, in the configuration of the present embodiment, the hard resin 24 wraps around the step 46a provided at the tip of the comb-shaped magnetic pole 46 from the inside, and the hard resin 24 presses the comb-shaped magnetic pole 46 from the inside. The warp toward the inside of the comb-shaped magnetic pole 46 is prevented.

 The housing connector 22 has a general-purpose shape. The housing connector 22 has six connector pins 22a protruding on the surface opposite to the mating surface. These connector pins 22a are bent substantially at right angles to one direction as shown in FIG.

 The housing connector 22 is inserted so that the bending direction of the connector pin 22a is outside the radial direction of the motor from the direction of the arrow B in FIG. 2 of the holding portion 18a. The connector pin 22a is held in a state of facing, preferably in contact with, the terminal pin 54. In this state, the holding portion 18a regulates the movement of the housing connector 22 in the upward and downward directions in the figure and in the direction normal to the plane of the drawing. With the movement of the housing connector 22 restricted in this way, the opposing or contacting connector pin 22a and terminal pin 54 are soldered. At this time, both are relatively fixed. Further, at this time, since the structure of the present invention is adopted as described above, the terminal pins 54 are arranged in a straight line. For this reason, it can be easily done by a method such as casting solder by a dedicated machine or a general-purpose machine robot.

 The soldered portion is covered with a lid 68. The shape of the lid portion 68 will be described with reference to FIG. In FIG. 14, the arcuate portion 70 has an arcuate shape having substantially the same diameter as that of the frame 12 having the C-shaped cross section, and covers the left side of the opening portion of the frame 12 in FIG. Protrusions 72 and 74 that extend slightly inward downward from both ends are formed on the lower side of the arc upper portion 70 in FIG. 14 (b). 74a is formed. A rectangular portion 76 is formed on the right side of the arcuate portion 70 in FIG. 14 (a), in which the housing connector 22 is housed and the right side is opened. Claws 76a and 76b directed inward are provided on the lower left and right sides of the rectangular portion 76 in FIG. 14 (a). The inner shape of the rectangular portion 76 is almost the same as the outer shape of the housing connector 22, and the claw portions 76a and 76b can hold the housing connector 22 on the upper side thereof. These claws 76a and 76b are set in positions so that the lower part 22b of the housing connector 22 that protrudes from the left end of the metal plate 18 in FIG. 2 can be locked. The right end of the rectangular portion 76 in FIG. 14 (a) comes into contact with the left end of the holding portion 18a of the metal plate 18 at the time of mounting, and cooperates with the holding portion 18a of the metal plate 18 to substantially cover the entire opening. Cover.

 The lid 68 is pressed against the outside of the opening of the frame 12. Then, the claws 72a, 74a, 76a, 76b are elastically deformed, the claws 76a, 76b lock the lower portion 22a of the housing connector 22, and the claws 72a, 74a fix the frame 12 in a predetermined position 12b. To be done. These claws 72a, 74a, 76a, 76b are held firmly because they lock the frame 12 and the housing connector 22. In particular, the claws 75a and 76b prevent the rectangular portion 76 from rising due to elastic deformation of the entire lid portion 68 when the arcuate portion 70 is pressed.

 The lead wire 78 connected to the external electrode is connected to a post connector 80 having a shape capable of being coupled to the housing connector 22. By providing a large number of post connectors 80 having lead wires 78 of different lengths in this device, the same motor can be used for a plurality of different uses. That is, in the motor of this embodiment, only the lead wire portion can be manufactured in a separate process depending on the application, and the common body portion can be used.

 In the step motor having the above-mentioned configuration, by applying a drive pulse to the lead wire of the post-connector connected to the housing connector, an electric current flows through the winding and a magnetic force is generated. Due to the action of this magnetic force, a driving force acts on the permanent magnet of the rotor and the rotor rotates.

 Further, in the above-mentioned embodiment, it is premised that the user selects the lead wire 78 from the manufactured or ready-made ones, but it may be attached before the factory shipment. Further, in this case, even if the two connectors 22 and 80 are bonded together in a bonded state, they are within the technical concept of the present invention. In this case, since the lead wire assembling process can be the final process, there is an effect that the lead wire does not interfere with other processes.

 Further, in the above-described embodiment, the example in which the stator is integrated with the hard resin is shown, but the present invention is not limited to this structure. For example, as shown in FIG. 15, it is possible to provide a cover for covering the periphery of the stator and position the respective members by the cover. At this time, if a protrusion is formed on the cover so as to engage with the V-shaped groove as shown in the figure, positioning in the circumferential direction becomes easy. At this time, it is desirable that the claw portions c are biased in a direction in which they engage with each other, and therefore, the core needs to be configured to be pressed in the vertical direction by means of a screw or the like.

By doing so, the winding frame is elastically deformed due to the uniformity of the winding of the winding frame and the other portion, and the urging force acts in the above direction.

 Further, in the above embodiment, the case where the resin protrusion 24a of the stator 26 is crushed by the end plate 16 has been described, but it may be crushed in advance to fix the metal plate 18 to the stator 26 and then welded. In this case, although the number of steps is increased, there is an effect that the above fixing can be surely performed even when there is a dimensional error.

 Other various modifications are possible without departing from the spirit of the present invention.

[Effects of the Invention] As is clear from the above description, in the present invention, the terminal pins to which the windings of the step motor are connected are aligned. This makes it easy to automate the subsequent processing of those terminal pins. Further, even when the terminal pin is used as it is, it has an excellent effect that it is aesthetically pleasing and the processing of the terminal pin is easy.

[Brief description of drawings]

 1 to 15 are drawings for explaining an embodiment of the present invention, and FIG. 1 is an explanatory view for explaining a state in which a projection claw of a terminal holder, which is a feature of the present invention, is engaged. 2 is a sectional view of the step motor of the present embodiment, FIG. 3 is a front view of the step motor of the present embodiment, and FIG. 4 is a partially cutaway perspective view showing the shapes of the stator and the rotor. Fig. 5 is a front view and a cross-sectional view showing the shape of the metal plate, Fig. 6 is an explanatory view for explaining the spot welding state of the frame and both end plates, and Fig. 7 shows the assembling state of the reel and the core. FIG. 8 is an exploded perspective view, FIG. 8 is an explanatory view showing a shape of a step provided at the tip of a comb-shaped magnetic pole, FIG. 9 is an explanatory view showing a shape of a protrusion of an end holder, and FIG. 10 is a core, FIG. 11 is an explanatory view showing a process of integrally fixing the winding frame and the bearing, and FIG. 11 is a circumferential direction of the core and the winding frame. Fig. 12 is a cross-sectional view showing how the metal plate is fixed, and Fig. 13 shows how the magnetic poles are warped when no steps are provided on the comb-shaped magnetic poles. FIG. 14 is a partially cutaway perspective view, FIG. 14 is a front view and a side view showing the shape of the lid portion, and FIG. 15 is a perspective view showing an example when the rotor is not integrated with hard resin. 16 to 18 are explanatory views of a conventional step motor. FIG. 16 is an exploded perspective view showing a structure of a stator of a conventional step motor, and FIG. 17 is a front view of the conventional step motor. FIG. 18 is a cross-sectional view showing the appearance of the winding frame and the winding. In the figure, 48 is a winding frame, 48c is a winding wire, 50 is a winding frame, 50c is a winding wire, 54 is a terminal pin, 54b is a protrusion, and c is a claw.

Claims (1)

[Claims] 1. A step motor in which a winding is wound and a plurality of winding frames having a plurality of projecting portions on which terminal pins are erected are stacked so that the projecting portions are alternately arranged. The protrusions are provided with claws, and the claws of the opposing winding frames are arranged so as to engage with each other, and the terminal pins are aligned at a position where the claws are engaged. Step motor characterized by being installed upright.