JP2671266B2 - Stepping motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepping motor, and in particular, two stators having two-phase exciting coils are installed in the axial direction of the rotor, and the rotor is rotated by unipolar drive. 4 phase stepping motor.

[Prior Art] In general, a unipolar driven four-phase stepping motor includes two stators and a rotor. Each stator is composed of a two-phase exciting coil composed of a bifilar winding, a stator core having a large number of claw poles, a common terminal, and a lead terminal. One end of each exciting coil is connected to a common terminal, and the other end is connected to a lead terminal for connecting to a transistor switch. The exciting coil and the stator core are integrally molded with synthetic resin. The stator thus configured is installed in the axial direction of the rotatable rotor.

When driving a stepping motor, first, connect each terminal of the stepping motor driving device equipped with a power supply and a switching circuit to each of the common terminal and the lead terminal of the stepping motor through a plurality of connecting wires (wire harness). Connecting. In this case, the common terminals are each connected to the power source of the stepping motor driving device, and the lead terminals are connected to the switching circuit of each stepping motor driving device. Next, the stepping motor drive device supplies current to the four-phase exciting coils in a predetermined order. As a result, current flows from one common terminal to the two-phase exciting coil. Each exciting coil is excited every time a current flows, and the rotor is rotated stepwise by a constant angle.

[Problems to be solved by the invention]

However, the connection line may be broken due to bending, pulling, or the like. In particular, when a failure such as a disconnection occurs in a connecting wire connecting each of the common terminal and the power supply, the two-phase exciting coil connected to the common terminal is not excited. As a result, an operation abnormality occurs in the stepping motor, and a problem occurs such that the rotation direction of the rotor cannot be specified, which makes it difficult to control the stepping motor.

The present invention has been made in consideration of the above facts, and an object thereof is to obtain a stepping motor capable of preventing the operation abnormality of the stepping motor due to the disconnection of a part of the connecting wires connected to the common terminal. is there.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a rotor, a plurality of stators each provided with a plurality of exciting coils and installed along the axial direction of the rotor, and a casing body made of synthetic resin for covering the outer surface of the stator. And each of the plurality of stators has a common terminal to which one end of each exciting coil of the stator is connected, and a terminal provided corresponding to each of the exciting coils, and the other end of each exciting coil. A plurality of connected individual terminals are respectively provided so as to project from each stator, and each common terminal of each stator is connected to a drive device through a power supply line, and the drive device supplies the power supply line. And electric power is supplied to each exciting coil of each stator via each common terminal, and each individual terminal of each stator is connected to the switching means of the drive device via a connecting wire. In a stepping motor driven by controlling excitation of each excitation coil of each stator by turning on / off the switching means, an insertion hole through which the common terminal is inserted, and each of the insertion holes inserted through the insertion hole, respectively. An electrically conductive and plate-shaped conducting means having a conductive holding portion for sandwiching the common terminal electrically connects the common terminals to each other, and the conducting means is embedded in the casing body. It is characterized by having done.

[Action]

In the present invention, each of the plurality of stators is provided with a plurality of exciting coils and is installed along the axial direction of the rotor, and each of the plurality of stators has a common terminal to which one end of each exciting coil of the stator is connected. , A plurality of individual terminals provided corresponding to each exciting coil and connected to the other end of each exciting coil are provided so as to project from each stator, and each common terminal of each stator is a power supply line. In the stepping motor, each individual terminal of each stator is connected to the switching means of the driving device via a connecting line, and the common terminals are electrically connected to each other by the conducting means. doing.

In the above stepping motor, electric power is supplied from the driving device to each exciting coil of each stator through the power supply line and each common terminal, and the excitation of each exciting coil of each stator is controlled by turning on / off the switching means of the driving device. As described above, by electrically connecting the common terminals to each other by the conducting means, as described above, disconnection or the like to any of the plurality of power supply lines connected to the common terminals. Even if the failure occurs, the common terminal connected to the failed power supply line is supplied with power through the power supply line connected to the other common terminal and the conduction means. Appropriate control of the stepping motor can be continued without causing an abnormal operation of the motor.

Further, in the present invention, the conductive means is conductive and plate-shaped,
An insertion hole through which the common terminal is inserted, and a conductive holding portion that holds each common terminal inserted through the insertion hole are provided.
By inserting the common terminals into the plate-shaped conducting means, the plurality of holding portions provided in the conducting means hold the common terminals, the common terminals are electrically connected, and the conducting means are provided on the outer surface of the stator. Embedded in a casing body made of a synthetic resin for covering. In this way, since the conducting means is plate-shaped, it is possible to prevent the conducting means itself from being broken, and since the clamping portion clamps the common terminal, vibration or the like generated when driving the stepping motor is added. However, the contact failure between the conducting means and the common terminal does not occur. Further, since the conducting means is embedded and fixed integrally in the casing body made of synthetic resin, it is possible to surely prevent the inconvenience such as the detaching of the conducting means from occurring.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a monopolar drive 4 according to this embodiment.
A phase stepping motor 10 is shown. The stepping motor 10 includes a casing 12 made of synthetic resin, which is composed of a main body 12A and a lid 12B. Inside the casing 12, both lateral ends are
A rotor 16 rotatably supported by A and 14B is arranged. At the same time as the rotor shaft, the rotor shaft 16A penetrates and projects into the rotor 16, and the rotor shaft 16A
The projecting portion of is penetrating a circular hole 12C provided in the lid 12B. On the outer circumference of the rotor 16, a cylindrical rotor magnet 18
Is attached. Further, annular stators 22 and 24 are installed on the outer periphery of the rotor magnet 18 with their axes aligned with the axis of the rotor 16. Each stator 22, 24
A constant gap is provided between the inner circumference of the rotor and the rotor magnet 18.

Here, the stator 22 and the stator 24 have the same structure, and the structure will be described below. Each of the stators 22 and 24 has a bobbin (not shown) having an annular, substantially U-shaped cross section, and stator coils 23 and 25, which are two-phase exciting coils, are wound around the outer circumference of each bobbin. Further, each of the stator cores 20A and 20B provided with a large number of claw poles is arranged so that the claw pole portion is located on the inner circumference of the bobbin. Further, the stator coils 23 and 25, the stator cores 20A and 2
OB and bobbin are integrally molded with synthetic resin to form stators 22 and 24. As shown in FIGS. 2 and 3, each stator coil 22, 24 has a terminal 26.
A, 26B, 26C and 28A, 28B, 28C are provided so as to protrude from the synthetic resin portion. The intermediate portions (see FIG. 3) of each of the stator coils 23 and 25 are connected to common terminals 26B and 28B, and the two-phase exciting coils 22A, 22B and 24A, 2 respectively.
Forming 4B. Each terminal 26A, 26B, 26C, 28A, 28B, 2
8C serves as a connection portion with a connector (not shown) provided on the connection line 34 and the power supply line 36. As shown in FIG.
The common terminals 26 and 26B are respectively connected to the other ends of power supply lines 36A and 36B, one ends of which are connected to the power supply of the stepping motor driving device. Each of the lead terminals 26A, 26C and 28A, 28C is connected to the other end of the connection lines 34A, 34B, 34C, 34D whose one end is connected to the switching element of the stepping motor drive device. The lead terminals 26A, 26C, 28A, 28C correspond to the individual terminals of the present invention.

Here, in the present embodiment, a conducting member 30 as conducting means is laid between the common terminals 26B and 28B. The conductive member 30 is a rectangular plate member made of a conductive material, which is bent at a substantially right angle so that both longitudinal ends thereof are parallel to each other.
It is almost U-shaped. Also, common terminals 26B and 28B when the stators 22 and 24 are assembled to the stepping motor 10.
Notches 30A and 30B are provided at a distance L (see FIG. 2) corresponding to the distance therebetween. The notches 30A and 30B are two notches that extend in the longitudinal direction of the conductive member 30 and are parallel to each other.
It is composed of one notch part connecting the middle parts of the two notch parts and is formed in a substantially H shape, and as shown in FIG. 4, the notch parts 30A, 30B respectively make a pair of tongue pieces. 31 and 33 are formed. The tongue pieces 31 and 33 are pushed up at the opposite ends thereof in FIG. As a result, a slight gap is generated between the tip portions of the tongue pieces 31 and 33, and the common terminal 26
B and 28B can be inserted. Notch 30 of the conductive member 30
When the common terminals 26B and 28B are penetrated to A and 30B, the tongue piece 3
1, 33 contact the common terminals 26B, 28B, and hold the common terminals 26B, 28B by the biasing force of the tongue pieces 31, 33 themselves.

The means for assembling the conduction member 30 to the stepping motor 10 will be described in more detail below. First, the common terminals 26B and 28B are connected to the cutout portion 30 of the conductive member 30 in a state where the stators are overlapped.
The common terminals 26B and 28B are electrically connected to each other by penetrating A and 30B. Next, the rotor shaft 16A and the rotor magnet 1
The rotor 16 to which 8 is attached and the bearings 14A and 14B are housed inside the annular stators 22 and 24. The rotor 16 has its both axial ends supported by bearings 14A and 14B so as to be rotatable. In this state, the outer surfaces of the stators 22 and 24 are covered with synthetic resin to form the casing body 12A. As a result, the conducting member 30 is embedded in the casing body 12A made of synthetic resin. Further, the rotor shaft 16A is inserted through the circular hole 12C provided in the lid body 12B, and the casing body 12A and the lid body
The stepping motor 10 is completed by joining with 12B. Here, the stepping motor drive device 32 and the stators 22 and 24 of the stepping motor 10 are electrically connected by connecting the connectors attached to the ends of the connection line 34 and the power supply line 36 to the terminals 26 and 28. Thus, the drive control of the stepping motor 10 becomes possible.

 Next, the operation of the present embodiment will be described.

In the stepping motor drive device 32, the four-phase exciting coils 22A, 22A
Current is applied to B, 24A, and 24B in a fixed order and excited. This causes the rotor 16 to rotate. A current flows through the coils 22A and 22B through the power supply line 36A, and a power supply line 3 passes through the coils 22A and 24B.
Current flows through 6B. When the rotation direction of the rotor 16 is reversed, the four-phase coils 22A, 22B, 24A, 24B may be excited in the opposite order.

Here, for example, when the power supply line 36A, which is one of the two power supply lines 36A and 36B, is disconnected, the current from the power supply line 36B flows through the coils 22A and 22B via the conductive member 30. As a result, the stepping motor 10 can be controlled as it was before the power supply line 36A was disconnected. Also, the power line
Even when the wire 36B is disconnected, the current from the power supply wire 36A flows through the coils 22A and 22B via the conductive member 30.

As described above, in the present embodiment, even if either one of the two power supply lines 36A and 36B is broken, the operation abnormality such as the rotation of the stepping motor 10 not being determined does not occur. The conductive member 30 is a casing body made of synthetic resin.
Since it is embedded in 12A, failure such as poor contact between the common terminals 26B and 28B and the conductive member 30 does not occur.

Further, due to the current flowing through the conducting member 30, the power supply lines 36A, 3A
You may install an alarm device to notify the disconnection of 6B.

As described above, the stepping motor according to the present embodiment does not cause an abnormal operation even if the wire breaks, and therefore is most suitable as a motor for a control device of an automobile, which is particularly required to have reliability.

〔The invention's effect〕

As described above, the stepping motor according to the present invention includes the insertion hole into which the common terminals of the plurality of stators are inserted, and the conductive pinching portion that holds the common terminals inserted into the insertion holes. The provided conductive and plate-shaped conducting means electrically connect the common terminals to which different power supply lines are connected to each other, and the conducting means is embedded in the casing body that covers the outer surface of the stator. Therefore, it is possible to prevent the operation abnormality of the stepping motor due to the disconnection of a part of the power supply line connected to the common terminal respectively, so that the proper control of the stepping motor can be continued and the stepping motor is driven. It is possible to reliably prevent the occurrence of inconveniences such as disconnection and disconnection of the conducting means itself caused by vibration and the like, and poor contact between the conducting means and the common terminal. It was having an effect.

[Brief description of the drawings]

FIG. 1 is a sectional view of a stepping motor according to this embodiment,
2 is a perspective view of the stator, FIG. 3 is a schematic block diagram showing a connection state between the stepping motor and the stepping motor driving device, and FIG. 4 is a stepping motor connecting portion viewed from the arrow A direction in FIG. FIG. 10 …… Stepping motor, 16 …… Rotor, 22 …… Stator, 24 …… Stator, 30 …… Conducting member, 32 …… Stepping motor drive unit, 34 …… Connection line, 36… Power line.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Saji 390 Umeda, Kosai City, Shizuoka Prefecture Asmo Co., Ltd. (56) References JP 59-63972 (JP, A) JP 56-70609 (JP, JP, 70609 A) Actual development Sho 55-23878 (JP, U)

Claims (1)

(57) [Claims] 1. A rotor, a plurality of stators each provided with a plurality of exciting coils and arranged along the axial direction of the rotor, and a casing body made of synthetic resin for covering the outer surface of the stator, Each of the plurality of stators includes
A common terminal to which one end of each exciting coil of the stator is connected, and a plurality of individual terminals that are respectively provided corresponding to the respective exciting coils and that are connected to the other end of each of the exciting coils are projected from the respective stators. And each common terminal of each stator is connected to a drive device via a power supply line, and from the drive device to each excitation coil of each stator via the power supply line and each common terminal. While being supplied with electric power, each individual terminal of each stator is connected to the switching means of the drive device via a connection line,
In a stepping motor driven by controlling excitation of each exciting coil of each stator by turning on / off the switching means, an insertion hole through which each common terminal is inserted, and each common through each insertion hole. By a conductive and plate-shaped conducting means having a conductive holding portion for holding the terminal,
A stepping motor, wherein the common terminals are electrically connected to each other and the conducting means is embedded in the casing body.