JP2729136B2 - Stepping motor drive control method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a stepping motor.
Drive the film damper to selectively select the air outlet
More particularly, the present invention relates to a stepping motor drive control method and apparatus for driving a rotor by exciting a stator coil of each phase in a stepping motor according to a predetermined order.

[0002]

2. Description of the Related Art PM type stepping motors are, for example, 2
In the phase excitation type, as shown in FIG. 7, two-phase coils are always excited, and by performing this excitation in a predetermined order, step driving can be performed with high accuracy. it can. For this reason, it is widely used as a drive source for electrical components that are widely installed in vehicles,
For example, it is applied to an air outlet adjustment mechanism in an air conditioner (hereinafter, referred to as an air conditioner) mounted on a vehicle.

In this air conditioner, the temperature is adjusted according to a set temperature, and the air is sent to a selected air outlet (a heater air outlet, a ventilation air outlet, etc.) through a duct into a vehicle interior.
It is designed to keep it at an appropriate temperature. This outlet is selected by disposing a thin sheet film-shaped damper in front of the outlet. A through-hole is provided in the longitudinal center of the sheet-film-shaped damper, and the outlet is selected according to the arrangement ratio of the elongated hole to the outlet (see JP-A-4-87826).

The sheet film-shaped damper has both ends in the longitudinal direction wound by winding rollers. A timing belt is wound between the winding rollers,
When one winding roller is rotated by the driving force of the PM type stepping motor, the other winding roller also rotates.

[0005] Here, by winding the sheet film-shaped damper around one of the winding rollers, the sheet film-shaped damper can be moved in the longitudinal direction, and the position of the through hole can be changed. This winding amount can be accurately determined by the number of pulses of the PM type stepping motor, and fine positioning can be performed.

Further, the film-shaped sheet-film damper is locked via a spring member to the other winding roller (the roller on the side not connected to the PM type stepping motor), and the tension is always maintained by the elastic force. Since it is engaged, slack does not occur not only during movement but also in a stopped state. For this reason, it is possible to prevent wind leakage, and it is also possible to eliminate fluttering noise due to blowing of warm air or cool air.

In a PM type stepping motor in which a rotor is constituted by a permanent magnet, a detent torque (non-excitation holding torque) is generated in a stopped state. That is,
When a permanent magnet is used for the rotor, a magnetic attractive force acts even in the case of non-excitation, and this acts as a force for maintaining the axial position of the motor.

[0008]

However, the driving torque is larger than the detent torque, and when the sheet film-shaped damper is completely wound around one of the winding rollers (the motor connecting side), the PM type stepping motor is fully wound. Is stopped, the sum (reaction force) of the tension of the sheet film damper and the tension of the spring member greatly exceeds the detent torque as shown in FIG. The occurrence of this unwinding causes a fluttering sound. Further, it is necessary to select a gear strength that can withstand such an excessive drive torque, and there is a problem that the gear portion becomes large.

In view of the above facts, the present invention reduces the driving torque of a motor and prevents a reaction force generated by driving the motor from exceeding a detent torque when the motor is stopped. And a device.

[0010]

According to a first aspect of the present invention, there is provided a passage port mounted on a drive shaft and through which air flows.
The film damper with
While being driven by the driving force of the stepping motor.
And the passage is communicated with a desired outlet.
Outlet adjustment mechanism in which the outlet is selectively switched
A drive control method of the stepping motor constituting the respective phases of the stator in the stepper motor
While energizing the coil according to a predetermined order,
It is characterized in that a period during which all phases are not excited is provided for each predetermined cycle.

According to a second aspect of the present invention, there is provided a driving shaft
Film holder having a passage opening through which air flows
The stepper while applying the urging force of the elastic member.
Driven by the driving force of the ping motor,
The outlet can be selected by communicating with the desired outlet
That constitutes an air outlet adjustment mechanism that can be switched
A drive control device for a stepping motor , comprising: a pulse generating means for generating a pulse having a constant period; and a stepping motor for driving the stepping motor in accordance with the pulse generated by the pulse generating means.
That has an excitation means for exciting the order defined for each phase advance of the stator coil, and inhibiting means for inhibiting all predetermined time the excitation of each phase by the excitation means every predetermined cycle, the.

[0012]

According to the first aspect of the present invention, the air outlet adjustment
Stator in Stepping Motor Constituting Regulating Mechanism
By energizing each phase of the coil in a predetermined order, step driving is performed according to the excitation. Therefore, by determining the number of times of excitation (pulse), drive control can be performed with high accuracy.

Here, if the excitation is continuously performed, the driving torque is large, and the reaction force generated by the driving force of the motor (for example, the force of the moving member moved by the driving force of the motor to return to the original position). Becomes larger. Therefore, by providing a time period in which all phases are not excited at every predetermined cycle, the reaction force of the motor drive is released when the detent torque is exceeded in this non-excitation state, and the accumulation of the reaction force is prevented.

Therefore, even when the motor is locked, the reaction force is not accumulated due to excessive torque, the strength of the gear portion attached to the rotary shaft can be set low, and the size can be reduced.

Further, since the reaction force does not greatly exceed the detent torque when the motor stops, no noise or the like is generated when the reaction force is released.

According to the second aspect of the present invention, the outlet adjusting mechanism according to the pulse generated by the pulse generating means.
Are excited according to a predetermined order in the stator coil of the stepping motor . By controlling the pulse generating means, the number of rotations and the rotation angle of the motor can be accurately controlled.

In the prohibition means, a time is provided for prohibiting the excitation of all phases by the excitation means. This time is set to a predetermined period, and when the reaction force by the motor drive exceeds the detent torque in this non-excitation state, the time is released.
No reaction force is accumulated. Therefore, even when the motor is locked, the accumulation of reaction force due to excessive torque is prevented.

[0018]

FIG. 3 is a schematic diagram showing an air conditioner 10 of a vehicle to which the present invention is applied.

As shown in FIG. 3, the external shape of the air conditioner 10 is constituted by a fan 12 and a duct 14 attached to an outlet of the fan 12. Air fed from the fan 12 passes through an evaporator 16 provided in the duct 14. This evaporator 16 generates low-humidity air. Further, the evaporated water is discharged to the outside through a drain 18 provided in the duct 14.

A heater core 20 is provided downstream of the evaporator 16, and the temperature of the air is adjusted by the heater core 20. The downstream side of the heater core 20 is branched into a plurality (three in this embodiment) of sub ducts 22A, 22B, and 22C, each of which has a ventilation outlet, a defroster outlet, not shown.
It communicates with the heater outlet.

The heater core 20 and the sub ducts 22A, 22
A damper unit 24 is disposed between B and 22C. In this damper unit 24, the heater core 20
The temperature-controlled air that has passed through any of the subducts 22A, 22A
B, 22C.

As shown in FIG. 4, the damper body of the damper unit 24 is formed by a film damper 26. The film damper 26 is long and is formed of a flexible and relatively strong member, and both ends in the longitudinal direction are wound around a pair of winding rollers 28 and 30.

The winding roller 28 has a slit (not shown) formed in a shaft portion 28A, and one end of the film damper 26 is locked. A pulley 28B is coaxially fixed to one end of the shaft 28A so as to be integrally rotated. The other end is connected to a drive shaft 32A protruding from a PM type stepping motor 32 (hereinafter simply referred to as a motor 32).

On the other hand, the winding roller 30 has a shaft portion 30A.
A slit (not shown) is formed in the film damper 2.
The other end of 6 is locked. A pulley 30B is pivotally supported at one end of the shaft portion 30A.
OB is relatively rotatable. A circular groove 30C is provided at the center of the pulley 30B, and the outer end of a mainspring 34 is locked on the inner peripheral surface. The inner end of the spring 34 is locked to a shaft 30A protruding from the bottom of the circular groove 30C. For this reason, the shaft portion 30A
Will rotate following the rotation of the pulley 30B.

Endless belts 36 are wound around the pulleys 28A on the winding roller 28 side and the pulleys 30B on the winding roller 30 side, respectively. Therefore, when the winding roller 28 is rotated by the driving force of the motor 32, the belt 3
6. The winding roller 30 is also rotated in the same direction via the mainspring 34.

The film damper 26 is wound in accordance with the rotation direction of the winding rollers 28 and 30 by the motor 32.
Unwinding will be performed. A plurality of long holes 26A are formed in the center of the film damper 26, and serve as passages for temperature-controlled air. That is, the slot 26A can be made to correspond to any of the sub ducts 22A, 22B, and 22C by the winding amount of the film damper 26 to the winding rollers 28 and 30, and the corresponding sub duct 22A,
Temperature-controlled air can be sent to either of 22B and 22C.

As shown in FIG. 5, the motor 32 applied to this embodiment is a PM type two-phase excitation type stepping motor, and the rotor 38 is constituted by a permanent magnet. One end of the rotating shaft 40 fitted into the shaft of the rotor 38 is connected to a reduction gear unit 42, from which the drive shaft 32A projects.

Around the rotor 38, two-phase stator coils 44 are provided, and by exciting these stator coils 44 in a predetermined order, the rotor 38 can be rotated. Rotor 38, stator coil 4
4 and a casing 46 covering the reduction gear unit 42
Is formed with a terminal connector section 46A, and each stator coil 44 can be excited by being connected to a connector (not shown) on the power supply side.

As shown in FIG. 6, the motor 32 is connected to the MPU 50 via a driver 48.
It is controlled by a signal from the PU 50. The MPU 50 generates a pulse signal having a constant period, and excites each stator coil 44 according to the pulse signal. That is, each of the two-phase stator coils 44 has an intermediate portion as a common terminal, and is excited by signals A, a, B, and b, respectively.

Here, in the MPU 50 of the present embodiment, a time is provided for prohibiting the excitation of the stator coil 44 at regular intervals. As shown in FIG. 1, in this embodiment, two-phase excitation is performed every other pulse, and a non-excitation time of time t is provided between them. During this non-excitation time, the drive torque becomes 0, and only the detent torque is generated.

Here, when the film damper 26 is wound around the winding roller 28 on the motor connection side, the sum of the tension of the film damper 26 itself and the urging force of the mainspring spring 34 near the full winding. It occurs as a reaction force of the force. In the MPU 50, by providing the non-excitation time, as shown in FIG. 2, the reaction force is controlled to be released when the detent torque is exceeded during the non-excitation time and not to be accumulated. Is also suppressed to be equal to or less than the detent torque.

The operation of this embodiment will be described below. When the fan 12 is driven, air is pumped from the outlet of the fan 12 and passes through the evaporator 16. By passing through the evaporator 16, low-humidity air is generated. This air passes through the heater core 20 and is subjected to temperature adjustment, and the temperature-controlled air is sent into the vehicle interior.
The occupant selects the desired outlet. For example, when the heater outlet (sub duct 22C) is selected, the MPU 50
In order to wind the elongated hole 26A provided in the film damper 26 onto the winding roller 28 or the winding roller 30 so as to correspond to the sub duct 22C, the motor 32 is driven by a predetermined number of pulses calculated from the current position.

When the motor 32 is driven, the winding roller 28
The shaft 28A of the take-up roller 30 follows the pulley 28B, the belt 36, the pulley 30B, and the mainspring spring 34, and the film damper 26 is wound around the shaft 30A. Can be taken.

By driving the motor 32 and the number of pulses corresponding to the selected outlet, the temperature-controlled air can be blown out from a desired outlet (such as the sub duct 22C).

Here, in order to obtain the number of pulses corresponding to the outlet, it is necessary to set the initial position of the film damper 26 (initialization). This initial position may be set such that the film damper 26 is fully wound on the winding roller 28 side, and this position may be set to, for example, 0 pulse.

Then, the motor 32 is driven so that the film damper 26 is completely wound on the winding roller 28. Here, conventionally, since the excitation of the stator coil 44 of the motor 32 is always performed, the sum of the tension of the fill damper 26 itself and the urging force of the mainspring spring 34 is accumulated until the winding is completed. After the motor stopped due to the force, unwinding sometimes occurred instantaneously.

However, in the present embodiment, a period during which the stator coil 44 of the motor 32 is not excited is provided every other pulse (ie, a state similar to the stopped state), and a state is generated in which only a detent torque is generated. When the force exceeds this detent torque, it is released, suppressing the accumulation of reaction force. For this reason, even in the full winding state, the reaction force is equal to or less than the detent torque, so that unwinding can be prevented.

By preventing the unwinding, the flutter of the film damper 26 is also eliminated, and the noise can be reduced.

Further, by performing the above-described excitation control, the driving torque as a whole is also reduced, so that a large and high-strength gear is not required, and the size of the apparatus can be reduced.

In this embodiment, the stator coil 44
The non-excitation time is provided in all the regions for the excitation of the film. However, the fluttering of the film damper 26 occurs because
Since it is only in the state of full winding on the winding roller 28,
Control may be performed such that the non-excitation time is provided only during the full winding. Normally, the entire winding is performed only at the time of initial position setting (initialization) immediately after the power is turned on. Therefore, only during this initialization, a non-excitation time may be provided.

In the present embodiment, the drive control of the motor 32 for winding the film damper 26 of the air conditioner 10 has been described as an example. However, any control that generates a reaction force can be applied.

[0042]

As described above, the method and apparatus for controlling the driving of a stepping motor according to the present invention reduce the driving torque of the motor and prevent the detent torque from being exceeded when the motor is stopped due to the driving of the motor. It has an excellent effect that it can be produced.

[Brief description of the drawings]

FIG. 1 is a time chart for exciting a stator coil of a motor applied to the present embodiment.

FIG. 2 is a reaction force characteristic diagram when a film damper is wound according to the present embodiment.

FIG. 3 is a schematic configuration diagram of an air conditioner according to the present embodiment.

FIG. 4 is a perspective view of a film damper unit.

FIG. 5 is a sectional view showing an internal configuration of the motor.

FIG. 6 is a control block diagram.

FIG. 7 is a time chart for exciting a stator coil of a conventional motor.

FIG. 8 is a reaction force characteristic diagram when a conventional sheet film-shaped damper is wound up.

[Description of Signs] 24 Damper unit 26 Film damper 32 PM type stepping motor 34 Mainspring 38 Rotor 44 Stator coil 50 MPU (pulse generating means, exciting means, inhibiting means)

Claims (2)

(57) [Claims] 1. An air circulation device mounted on a drive shaft.
The film damper having a passage opening for
Driven by stepping motor while applying biasing force
Driven, the passage opening communicates with the desired outlet
Outlets, the outlets of which are selectively switched by
A drive control method of the stepping motor constituting a mouth adjusting mechanism , wherein a stator coil of each phase in the stepping motor is provided.
And a step in which all phases are not excited at predetermined intervals. 2. The apparatus is mounted on a drive shaft and circulates air.
The film damper having a passage opening for
Driven by stepping motor while applying biasing force
Driven, the passage opening communicates with the desired outlet
Outlets, the outlets of which are selectively switched by
Drive control device for stepping motor constituting mouth adjustment mechanism
A pulse generating means for generating a pulse having a constant period; and
Having an exciting means for exciting accordance with a predetermined order each phase of the stator coil in the stepping motor, and inhibiting means for inhibiting all predetermined time the excitation of each phase by the excitation means every predetermined cycle, the Stepping motor drive controller.