JP2004262395A - Electric actuator system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a value of lock current small by simple constitution and to suppress impact force when locked, in an electric actuator system. <P>SOLUTION: This system has a DC motor 110 to rotate an output shaft 111 by voltage imparted from a battery B. The output shaft 111 is stopped at a first stopping position by a stopper 5a in the state in which the output shaft 111 is normally rotated and power is supplied to the DC motor 110. The output shaft 111 is stopped at a second stopping position by a stopper 5b in the state in which the output shaft 111 is rotated in a reverse direction and power is supplied to the DC motor 110. The system is provided with a resistance element 270 for dividing voltage imparted from the battery B together with the DC motor 110. The resistance element 270 divides voltage imparted from the battery B together with the DC motor 110, and thereby the value of lock current flowing in the DC motor 110 can be made small. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric actuator system, and is effective when applied to an electric actuator system that drives a movable member such as various plate doors of a vehicle air conditioner.
[0002]
2. Description of the Related Art
Conventionally, an electric actuator system includes a DC motor and a lever that rotates in accordance with rotation of an output shaft of the DC motor. And stop the lever at the second stop position by rotating the output shaft in the reverse direction to abut against the second stopper member.
[0003]
In such a system, when the power is continuously supplied to the DC motor while the lever is mechanically stopped by the first and second stopper members, the DC motor is stopped regardless of the rotation stop state of the DC motor. It is considered that a lock current flows through the DC motor, and the lock current may shorten the life of the DC motor.
[0004]
Therefore, it is conceivable to provide a timer circuit or the like and stop the power supply to the DC motor after a certain period of time. However, there is a problem that the circuit configuration of the control circuit or the like becomes complicated. Further, when the lever is mechanically stopped by the first and second stopper members, an impact is applied and the electric actuator system and the stopper member are easily broken.
[0005]
In view of the above, an object of the present invention is to provide an electric actuator system that has a simple configuration and suppresses a lock current flowing in a DC motor.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, there is provided an electric motor that receives a voltage from a power supply device and rotates an output shaft, and the output shaft is rotated forward to provide an electric motor. While the power is supplied, the output shaft is mechanically stopped at the first stop position, and the output shaft is reversely rotated to mechanically move the output shaft to the second stop position while the electric motor is supplied with power. An electric actuator system for stopping at the stop position of (1), characterized by comprising a resistance element for dividing the voltage supplied from the power supply device together with the electric motor.
[0007]
Further, in the invention according to claim 4, there is provided an electric motor that is supplied with a voltage from a power supply device and rotates an output shaft, and the output shaft is rotated in a state where power is supplied to the electric motor by rotating the output shaft. An electric actuator system for mechanically stopping at a stop position, comprising a resistance element for dividing a voltage supplied from a power supply device together with an electric motor.
[0008]
According to the first and fourth aspects of the present invention, since the resistance element divides the voltage supplied from the power supply device together with the electric motor, the value of the lock current flowing through the electric motor can be reduced. As a result, the lock current value can be reduced with a simple configuration including only the resistance element, and the life of the electric motor can be prevented from being shortened. Further, since the lock current is reduced, the lock torque of the electric motor can be reduced, and the impact force at the time of lock can be suppressed.
[0009]
In the invention described in claim 2, it is preferable to use a resistance value of the resistance element of 50Ω to 150Ω.
[0010]
Specifically, it is preferable to apply the electric actuator system according to claim 1 or 2 to a vehicle air conditioner as in the invention according to claim 3. In this case, as in the third aspect of the invention, the vehicle air conditioner has an inside air introduction port for introducing air inside the vehicle compartment and an outside air introduction port for introducing air outside the vehicle compartment. A case, and a switching door rotatably supported by the air-conditioning case and rotated by an output shaft of the electric motor, wherein the switching door is configured to stop when the output shaft is mechanically stopped at the first stop position. The inside air inlet is opened to close the outside air inlet, and when the output shaft is mechanically stopped at the second stop position, the outside air inlet is opened to close the inside air inlet. .
[0011]
Incidentally, reference numerals in parentheses of the above-mentioned units are examples showing the correspondence with specific units described in the embodiments described later.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an electric actuator system (hereinafter, simply referred to as an actuator) according to a first embodiment of the present invention applied to a drive device of an air mixing door of a vehicle air conditioner 300 that performs air conditioning in a vehicle cabin. Hereinafter, an outline of the vehicle air conditioner 300 will be described with reference to FIG.
[0013]
The vehicle air conditioner 300 includes an air conditioning case 305 housed in an instrument panel. In the air conditioning case 305, an inside / outside air switching door 307 is rotatably supported by the case 305, and is driven by an actuator 319. Originally, the air conditioner is switched to the first switching position (the position indicated by the solid line in the figure) to allow the outside air to flow into the air conditioning case 305 from the outside air inlet 305a, while the second switching position (the position indicated by the broken line in the figure) And the air (inside air) in the passenger compartment 303 flows into the air conditioning case 305 from the inside air inlet 305b.
[0014]
Then, the blower 309 sends the outside air from the outside air introduction port 305a or the inside air from the inside air introduction port 305b to the evaporator 311 as an airflow according to the rotation speed of the blower motor 323 driven by the drive circuit 321. The airflow blown from the blower 309 is cooled by a circulating refrigerant by the operation of a known refrigeration cycle.
[0015]
The air mix door 313 is rotatably supported by the case 305, and is driven by an actuator (servo motor) 325 so that the cooling air flow blown out from the evaporator 311 and the air flow flowing into the heater core 315 and the heater core 315. 315 is divided into a bypass airflow (hereinafter referred to as a bypass cooling airflow).
[0016]
Here, the airflow flowing into the heater core 315 is heated by the engine cooling water (warm water) in the heater core 315, so that warm air is blown from the heater core 315. Accordingly, the hot air blown out from the heater core 315 and the bypass cooling airflow are mixed and flow toward the outlet switching door 317. The mixing ratio SW (%) between the hot air and the bypass cooling airflow is determined by the opening of the air mix door 313.
[0017]
The outlet switching door 317 is rotatably supported by the case 305, and is switched to a first switching position (a position shown by a two-dot chain line in the figure) in the face mode under the drive of the actuator 327. Then, air is blown out from the air outlet 305c toward the upper body of the occupant in the vehicle interior 303, and is switched to the second switching position (the position shown by the broken line in the drawing) in the foot mode. The air is blown out toward the feet of the occupant, and is switched to the third switching position (the position shown by the solid line in the figure) in the bi-level mode, and the air is blown out from both the air outlets 305c and 305d. The doors 307, 313, and 317 are individually formed in a plate shape.
[0018]
The electronic control unit 330 includes an inside air temperature sensor 331 for detecting the indoor temperature Tr in the vehicle interior 303, a solar radiation sensor 332 for detecting the solar radiation intensity Ts applied to the interior of the vehicle interior 303, and an outside for detecting the outside air temperature Tam outside the vehicle interior. Output signals are read from an air temperature sensor 333, a temperature setting device (temperature setting means) 334 for the occupant to set a set temperature Tset in the vehicle interior as a control target, and the like. Then, the electronic control unit 30 substitutes Tr, Ts, Tam, and Tset into the pre-stored formula 1 to obtain the required blowout temperature TAO, and controls the actuator 327 and the blower motor 323 based on the required blowout temperature TAO. Kest, Kr, Kam and Ks are the gains of the output signals of the respective sensors, and C is a constant.
[0019]
(Equation 1)
TAO = Kest, Tset-Kr, Tr-Kam, Tam-Ks, Ts + C
Further, the electronic control unit 330 receives a water temperature sensor 335 for detecting the temperature Th of the cooling water for cooling the traveling engine, an outlet temperature sensor 336 for detecting the temperature (outlet temperature) Te of the cool air blown from the evaporator 311, and the like. The output signal is read, and the mixture ratio SW (%) is obtained by substituting Te, Th, and TAO into Equation 2 stored in advance.
[0020]
(Equation 2)
SW = {(TAO-Te) / (Th-Te)} × 100
Here, the mixture ratio SW (%) corresponds to the opening degree of the air mix door 313 on a one-to-one basis, and the electronic control unit 330 determines the target opening of the air mix door 313 based on the mixture ratio SW (%). In addition to obtaining the degree, the actuator 325 is controlled so that the detected opening of the air mix door 313 approaches the target opening. The detected opening is detected by an opening sensor 337 built in the actuator 325.
[0021]
Next, the configuration of the actuator 319 that drives the inside / outside air switching door 307 will be described.
[0022]
FIG. 2 is an external view of the actuator 319. The actuator 319 includes a casing 140, a DC motor (electric motor) 110 housed in the casing 140, and a reduction mechanism 120. The DC motor 110 includes a battery (power supply device). ) To rotate forward or reverse with electric power.
[0023]
The speed reduction mechanism 120 is a speed change mechanism that reduces the rotational force input from the DC motor 110 and outputs it to the air mix door 313. The worm 121 is press-fitted into the output shaft 111 of the motor 110, and the worm meshes with the worm 121. An output shaft 127 is provided on a final gear (output-side gear) 126 which is a gear train including a wheel 122 and a plurality of spur gears 123, 124, and 125 located on the output side.
[0024]
Further, a link lever 160 for swinging the inside / outside air switching door 307 is press-fitted and fixed to the output shaft 127. Further, the air conditioning case 305 is provided with stoppers (stopper members) 5a and 5b for causing the link lever (rotating member) 160 to collide.
[0025]
Next, an electric circuit configuration for controlling the actuator 313 will be described with reference to FIG. FIG. 3 is a schematic diagram showing the electronic control device 330 of the actuator 313.
[0026]
The electronic control unit 330 includes a motor drive circuit 210 for rotating the DC motor 110 in the forward and reverse directions, a storage circuit 230 for storing input information such as an EEPROM for storing various control information without receiving power supply, and a motor drive circuit 210. , A constant voltage circuit 260 that converts a battery voltage from the battery B into a constant voltage and outputs the voltage to the circuits 230 and 240, and a resistance element 270 connected in series to the DC motor 110.
[0027]
The motor drive circuit 210 is a full-bridge circuit composed of relay switches 211 to 214. This full-bridge circuit switches the direction of a current flowing to the DC motor 110 as described later.
[0028]
In the present embodiment configured as described above, for example, when the occupant operates the operation switch 36 to switch to the inside air introduction mode, the CPU 240 turns on the relay switches 211 and 213 of the motor drive circuit 210. And the relay switches 212 and 214 are turned off. Accordingly, a current flows from the battery B to the ground via the ignition switch IG, the relay switch 211, the DC motor 110, the resistance element 270, and the relay switch 213. Therefore, the output shaft 111 of the DC motor 110 rotates forward.
[0029]
The rotation of the DC motor 110 is transmitted to the output shaft 127 via the speed reduction mechanism 120. Therefore, since the output shaft 127 rotates with the rotation of the DC motor 110, the link lever 160 rotates forward and hits the stopper 5a. As a result, the rotation of the DC motor 110 is stopped at the first stop position while the power is being supplied to the DC motor 110.
[0030]
With such a link lever 160, the inside / outside air switching door 307 rotates and stops at the first switching position (the position indicated by the solid line in FIG. 1), so that the inside / outside air switching door 307 opens the inside air introduction port 305b and introduces outside air. The mouth 305a will be closed.
[0031]
On the other hand, when the occupant operates the operation switch 36 to switch to the outside air introduction mode, the CPU 240 turns off the relay switches 211 and 213 of the motor drive circuit 210 and turns on the relay switches 212 and 214. Accordingly, a current flows from the battery B to the ground via the ignition switch IG, the relay switch 214, the resistance element 270, the DC motor 110, and the relay switch 212. Therefore, the output shaft 111 of the DC motor 110 rotates in the reverse direction.
[0032]
The rotation of the DC motor 110 is transmitted to the output shaft 127 via the speed reduction mechanism 120. Therefore, the output shaft 127 rotates in the reverse direction with the rotation of the DC motor 110, and the link lever 160 rotates in the reverse direction and hits the stopper 5b. As a result, the rotation of the DC motor 110 is stopped at the second stop position in a state where power is supplied to the DC motor 110.
[0033]
With such a link lever 160, the inside / outside air switching door 307 rotates and stops at the second switching position (the position shown by the broken line in FIG. 1), so that the inside / outside air switching door 307 opens the outside air introduction port 305a and introduces inside air. The mouth 305b will be closed.
[0034]
According to the above, when the rotation of the DC motor 110 is stopped at the first and second stop positions in a state where the power is supplied to the DC motor 110, the DC motor 110 receives the lock current, Since the motor 110 and the resistance element 270 divide the battery voltage applied from the battery B, the value of the lock current can be reduced as shown in FIG. 4 as compared with the case where the resistance element 270 is not used.
[0035]
In FIG. 4, the vertical axis represents the lock current flowing when the rotation of the DC motor 110 is locked by the stopper 5a (5b), the horizontal axis represents the value of the resistance element 270, and G represents the resistance element 270 ranging from 0Ω to 200Ω. 6 is a graph showing a change in lock current when the change is made in FIG. For example, when the resistance element 270 is 100Ω, the lock current is 0.08 A, and when the resistance element 270 is not used, the lock current is 0.26 A. Therefore, when the resistance element 270 of 100Ω is used, the lock current is 31 A. % Can be reduced.
[0036]
Next, an experimental result for examining a change in the voltage applied to the resistance element 270 and the DC motor 110 with a change in the resistance value of the resistance element 270 will be described with reference to FIG.
[0037]
5, the vertical axis represents the applied voltage (V) to DC motor 110 and resistance element 270, and the horizontal axis represents the resistance value (Ω) of resistance element 270. S1 is a graph showing a voltage applied to the DC motor 110 when the DC motor 110 rotates (hereinafter referred to as a motor operating voltage), and S2 is a state in which the rotation of the DC motor 110 is locked by the stopper 5a (5b). 5 is a graph showing a voltage applied to the DC motor 110 when the DC motor 110 is ON. S3 is a graph showing a voltage applied to the resistance element 270 when the rotation of the DC motor 110 is locked by the stopper 5a (5b). S4 is a graph showing a voltage applied to the resistance element 270 when the DC motor 110 rotates. It is a graph shown.
[0038]
Here, as shown in the graph S1, for example, when the resistance element 270 is 200Ω or less, the voltage at the time of motor operation is 3 compared to the case where the resistance element 270 is not used (that is, the case where the resistance element 270 is 0Ω). (V) The extent is lower.
[0039]
For this reason, even if the resistance element 270 is added, as shown in FIG. 6, when the resistance element 270 is changed from 0Ω to 200Ω, the decrease in the rotation speed of the DC motor 110 is reduced by about 1.1 (rpm). Can be suppressed. In FIG. 6, the vertical axis represents the rotation speed of the DC motor 110, the horizontal axis represents the value of the resistance element 270, and H represents the rotation speed of the DC motor 110 when the resistance element 270 is changed from 0Ω to 200Ω. It is a graph. According to the graph H, when the resistance element 270 has a value of 50Ω to 150Ω, the rotation speed of the DC motor 110 slightly decreases, which is suitable for lowering the lock current. In particular, when the resistance element 270 has 100Ω, the rotation speed is 3.4 rpm, and this rotation speed 3.4 rpm corresponds to 86% of the rotation speed 4 rpm when the resistance element 270 is not used. Therefore, it can be seen that the rotation speed is slightly reduced by using the resistance element 270.
[0040]
When the resistance element 270 is added, the power consumption of the DC motor 110 can be reduced as shown in FIG. In FIG. 7, the vertical axis represents power (W), the horizontal axis represents the value of the resistance element 270, K1 represents the power consumption of the DC motor 110 when the resistance element 270 is changed from 0Ω to 200Ω, and K2 represents the resistance element 270. Is a graph showing the power consumption of the resistance element 270 when the resistance is changed from 0Ω to 200Ω, and K3 is a graph showing the power consumption of the resistance element 270 and the DC motor 110 when the resistance element 270 is changed from 0Ω to 200Ω.
[0041]
Here, according to the graph K1, the power consumption of the DC motor 110 when the resistance element 270 is 100Ω is 0.31 W, and this 0.31 W is the power consumption of the DC motor 110 when the resistance element 270 is not used. : Equivalent to 10% of 3.1 W, and it can be seen that the power consumption of the DC motor 110 was significantly reduced by the addition of the resistance element 270.
[0042]
Hereinafter, the operation and effect of the present embodiment will be described. That is, since resistance element 270 divides the battery voltage provided from battery B together with DC motor 110, the value of the lock current flowing through DC motor 110 can be reduced. This makes it possible to reduce the value of the lock current with a simple configuration including only the resistance element, and to suppress shortening of the life of the DC motor. In addition, since the voltage applied to the DC motor 110 is very small even when the resistance element 270 is employed, the function as an actuator for rotating the inside / outside air switching door 307 while suppressing the shortening of the life is suppressed. Can be fulfilled enough. Further, since the lock current is reduced, the lock torque of the electric motor can be reduced, and the impact force on the stoppers 5a and 5b by the link lever 160 during locking can be suppressed.
[0043]
Further, conventionally, a potential meter that generates a pulse signal when rotated to the first and second switching positions using a switch pattern or a brush is used, and the inside / outside air switching door 307 is moved to the first position in response to the pulse signal output from the potential meter. An actuator that stops at the second switching position has been proposed.
[0044]
However, in this case, the inside / outside air switching door 307 is not mechanically stopped at the first and second switching positions. Therefore, in the present embodiment using the mechanical means such as the link lever 160 and the stoppers 5a and 5b, the inside / outside air switching door 307 can be stopped more accurately than the conventional actuator using the above-described potential meter. Can be.
[0045]
Further, in the present embodiment, the inside / outside air switching door 307 is stopped at the first and second switching positions while power is supplied to the DC motor 110. Therefore, even if the switching door 307 is stopped at the first and second switching positions, the DC motor 110 applies a rotational force to the inside / outside air switching door 307. Therefore, even when a force is applied to the inside / outside air switching door 307 from outside due to vibration or the like, the state in which the switching door 307 is stopped at the first and second switching positions can be maintained.
[0046]
(Other embodiments)
In the above-described embodiment, an example has been described in which the link lever 160 collides with the 5a and 5b to mechanically stop the rotation of the output shaft 111 of the DC motor 110 at the first and second stop positions. However, if the rotation of the output shaft 111 of the DC motor 110 is mechanically stopped at the first and second stop positions, not only the case where the link lever 160 and the stoppers 5a and 5b are used, but also various types of brake mechanisms are used. May be.
[0047]
In the above-described embodiment, an example has been described in which the rotation of the output shaft 111 of the DC motor 110 is mechanically stopped at the first and second stop positions. However, instead of using the two stoppers 5a and 5b, The rotation of the output shaft 111 of the DC motor 110 may be mechanically stopped at only one stop position by employing only one stopper.
[0048]
That is, the electric actuator system includes a DC motor 110 (electric motor) that receives a battery voltage from a battery B (power supply device) to rotate the output shaft 11, and rotates the output shaft 111 to supply electric power to the DC motor 110. Is an actuator that mechanically stops the output shaft 111 at the stop position in a state where the voltage is supplied, and includes a resistance element 270 for dividing the battery voltage supplied from the battery B together with the DC motor 110. In this case, as the electric actuator system, the air mix door 313 and the air outlet switching door 317 may be driven other than the inside / outside air switching door 307.
[0049]
In the above-described embodiment, an example in which the DC motor 110 is used as the electric motor has been described. However, the invention is not limited thereto, and various motors such as an AC electric motor may be used.
[0050]
In the above-described embodiment, an example in which the motor drive circuit 210 is configured using the relay switches 211 to 214 is described. However, the present invention is not limited to this, and various semiconductor switch elements such as a bipolar transistor and a field-effect transistor may be used. good.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a vehicle air conditioner.
FIG. 2 is an external view of the electric actuator according to the first embodiment of the present invention.
FIG. 3 is a block diagram illustrating a schematic electric circuit of the electronic control device according to the first embodiment.
FIG. 4 is a diagram showing a relationship between a lock current and a resistance element according to the first embodiment.
FIG. 5 is a diagram illustrating a relationship between a voltage applied to a DC motor and a resistance element according to the first embodiment.
FIG. 6 is a diagram showing the relationship between the rotational speed and the resistance element of the DC motor according to the first embodiment.
FIG. 7 is a diagram illustrating a relationship between power consumption and a resistance element of the DC motor according to the first embodiment.
[Explanation of symbols]
110: DC motor, 120: reduction mechanism, 210: motor drive circuit,
230: storage circuit, 240: CPU, 260: constant voltage circuit,
319 ... actuator, B ... battery, 330 ... electronic control device.

Claims (4)

Having an electric motor that is supplied with a voltage from a power supply device and rotates an output shaft,
The output shaft is mechanically stopped at the first stop position in a state where the electric power is supplied to the electric motor by rotating the output shaft forward, and the output shaft is rotated in the reverse direction to supply electric power to the electric motor. An electric actuator system for mechanically stopping the output shaft at the second stop position in a state where
An electric actuator system comprising a resistance element for dividing a voltage supplied from the power supply device together with the electric motor. The electric actuator system according to claim 1, wherein the resistance value of the resistance element is 50Ω to 150Ω. A vehicle air conditioner comprising the electric actuator system according to claim 1 or 2,
An air conditioning case having an inside air introduction port for introducing air inside the vehicle compartment and an outside air introduction port for introducing air outside the vehicle compartment, and rotatably supported by the air conditioning case, and an output shaft of the electric motor. A switching door that is rotated,
The switching door opens the inside air inlet and closes the outside air inlet when the output shaft is mechanically stopped at a first stop position, and the output shaft is mechanically stopped at a second stop position. An air conditioner for a vehicle, wherein when stopped, the outside air inlet is opened and the inside air inlet is closed. Having an electric motor that is supplied with a voltage from a power supply device and rotates an output shaft,
An electric actuator system for rotating the output shaft and mechanically stopping the output shaft at a stop position in a state where power is supplied to the electric motor,
An electric actuator system comprising a resistance element for dividing a voltage supplied from the power supply device together with the electric motor.

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