JP2008252983A - Servo motor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a servo motor 12 and the like to easily restore its operation when no failure occurs with the servo motor. <P>SOLUTION: When an air mix door 6 is located at upper side from the upper limit position at the time of starting, YES is selected in step S100. Furthermore, when the air mix door 6 is located at the lower side from the lower limit position, YES is also selected in step S110. When YES is selected in either step of S100 and S110, the position of the air mix door 6 is judged to be abnormal, and control passes to step S120, in which the servo motor 12 is driven to return the position of the air mix door 6 to a range of position that a potentiometer 12a can detect so that normal control can take place. Even when YES is selected in step S100 or step S110 in spite that the servo motor 12 does not fail in normal control before starting, the operation can be restored at the time of subsequent starting. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a servo motor system that controls an electric motor that drives a movable member.

2. Description of the Related Art Conventionally, some vehicle air conditioners include a servo motor that drives an air mix door via a link mechanism, and an electronic control device that controls the servo motor so that the position of the air mix door approaches a target position. (For example, refer to Patent Document 1).
JP 2004-345531 A

  When this inventor examined the door position control based on the above-mentioned patent document 1, the following problems were found.

  That is, as shown in FIG. 4, the lower limit position is set on the lower side of the normal operation range ht in the operable range Ha of the air mix door, and the upper limit position is set on the upper side of the normal operation range ht.

  Here, when the air mix door is positioned below the lower limit position and below, or when the air mix door is positioned above the upper limit position, the servo motor is stopped and cannot be operated. To. This prevents the air mix door from colliding with the case or the like and being damaged when an abnormality occurs in the servo motor or the like.

  However, the servo motor cannot be operated because the air mix door exceeds the upper limit position or the lower limit position even if the servo motor has not been damaged due to dimensional deviation of the link mechanism, servo motor, etc. It may become.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a servo motor system that can be easily restored when the servo motor becomes inoperable even though the servo motor has not failed.

  In order to achieve the above object, according to the present invention, the position of the movable member is based on the electric motor (12) for driving the movable member, the detection means (12a) for detecting the position of the movable member, and the detection position of the detection means. Motor control means (S130) for controlling the electric motor so as to be close to the target position within the normal operating range, and whether the position of the movable member has exceeded the limit position outside the normal operating range based on the detection position of the detection means When the determination means (S230, S240) and the determination means determine that the position of the movable member exceeds the limit position, the motor cannot be operated because the position of the movable member is abnormal. Means (S250), and when starting, when the determination means determines that the position of the movable member is abnormal, the motor inoperable means Without execution, characterized in that it comprises a start control means within the detection range of the detecting means to return the position of the movable member (S120).

  Therefore, even if the position of the movable member is abnormal and the motor inoperable means disables the operation of the electric motor, the motor inoperable means is not executed at the subsequent start-up and within the normal operating range. Activation control means for returning the position of the movable member is implemented. For this reason, when a failure does not occur in the electric motor or the like, it can be easily restored.

  In addition, the code | symbol in the bracket | parenthesis of each means described in a claim and this column shows the correspondence with the specific means as described in embodiment mentioned later.

  1 and 2 show an embodiment of a vehicle air conditioner to which the servo motor system of the present invention is applied.

  The vehicle air conditioner includes an air conditioning casing 1 that allows air to flow into the vehicle interior, an inside / outside air switching door 2 that selectively opens and closes the inside air introduction port 2a and the outside air introduction port 2b, and the inside air introduction port 2a and the outside air introduction port 2b. The air is sucked from one of the fan unit 3 for blowing air into the vehicle compartment, the cooling heat exchanger 4 for cooling the air blown from the fan unit 3, and the cooling heat exchanger 4. And a heating heat exchanger 5 for heating the cooled air.

  The cooling heat exchanger 4 constitutes a well-known refrigeration cycle apparatus that circulates refrigerant together with a compressor, a condenser, and a decompressor, and cools by exchanging heat with the blown air from the blower unit 3 by evaporation of the refrigerant. . The heating heat exchanger 5 heats cold air from the cooling heat exchanger 4 by circulating engine cooling water (heat source hot water) from the traveling engine 5a.

  In the air conditioning casing 1, there is provided a cold air bypass passage 1 a that bypasses the heating heat exchanger 5 and flows cooling air. An air mix door 6 is provided in the air conditioning casing 1 to adjust the ratio of the amount of air flowing through the cold air bypass passage 1a and the amount of air flowing through the heating heat exchanger 5 to adjust the temperature of air blown into the passenger compartment. ing.

  On the downstream side of the cold air bypass passage 1 a and the heating heat exchanger 5, a mixing chamber 7 for mixing the cold air from the cold air bypass passage 1 a and the hot air from the heating heat exchanger 5 is provided. The air mixed in the mixing chamber 7 is blown out from the face air outlet 8a, the foot air outlet 8b, or the differential air outlet 8c toward the vehicle interior. Mode doors 9a, 9b, and 9c for opening and closing the air outlets 8a, 8b, and 8c, respectively, are provided.

  In the present embodiment, plate doors that are rotatably supported are used as the doors 2, 6, 9a, 9b, and 9c. The doors 2, 6, 9a to 9c are rotationally driven by servo motors 11, 12, and 13 via a link mechanism.

  FIG. 2 shows the structure of the link mechanism of the air mix door 6 as a specific example of the link mechanism.

  The air mix door 6 is rotatably supported with respect to the support shaft 6a. A link member 140 having a link groove 140 </ b> A is fixed to the air mix door 6. A link lever 131 is fixed to the output shaft 132 of the servo motor 12, and a link pin 130 is provided at the tip of the link lever 131. The link pin 130 is disposed in the link groove 140 </ b> A of the link member 140.

  Thereby, when the output shaft 132 of the servo motor 12 rotates, the link lever 131 rotates. Accordingly, the link pin 130 of the link lever 131 slides in the link groove 140A of the link member 140. For this reason, the rotational force of the link lever 131 is transmitted to the link member 140, and the air mix door 6 rotates.

  Next, an outline of the electrical configuration of the present embodiment will be described.

  As shown in FIG. 2, the vehicle air conditioner includes an air conditioner ECU 10, servo motors 11, 12, 13, an inside air sensor 16, an outside air sensor 17, a water temperature sensor 18, and a temperature setting device 19.

  The air conditioner ECU 10 is an electronic control device including a microcomputer, a memory, and the like. Based on this, position control of the doors 2, 6, 9a, 9b, and 9c (that is, control of the door opening degree) and rotation speed control of the blower motor 3a of the blower unit 3 (that is, control of the air flow rate) are performed.

  Here, the required blowing temperature TAO is the blowing air temperature necessary for maintaining the vehicle interior at the set temperature test regardless of the change in the environment in the vehicle interior.

  The blower motor 3a is an electric motor for rotationally driving the impeller of the blower unit 3, and the number of rotations (i.e., the amount of blown air) of the blower motor 3a is determined based on the required blowing temperature TAO as is well known.

  The servo motor 11 is an electric motor for driving the inside / outside air switching door 2 via a link mechanism. The servo motor 12 is an electric motor for driving the air mix door 6 via a link mechanism. The servo motor 13 independently drives the mode doors 9a, 9b, 9c via the link mechanism.

  Potentiometers 11 a, 12 a, and 13 a that detect the rotation angle of the drive shaft (that is, the position of the door) are provided corresponding to each of the servo motors 11, 12, and 13. The potentiometers 11a, 12a, and 13a each generate an output voltage pt that changes in response to a change in the rotation angle of the drive shaft. The output voltages pt of the potentiometers 11a, 12a, and 13a are used for position control of the doors 2, 6, 9a, 9b, and 9c.

  Here, the output voltage pt of the potentiometer 11a and the rotation angle of the drive shaft of the servo motor 11 are set to be specified on a one-to-one basis. Similarly, the output voltage pt of the potentiometer 12a and the rotation angle of the drive shaft of the servo motor 12 are set to be identified on a one-to-one basis, and the output voltage pt of the potentiometer 13a and the rotation angle of the drive shaft of the servo motor 13 are Are set to be identified on a one-to-one basis.

  The inside air sensor 16 is a temperature sensor that detects the air temperature in the passenger compartment. The outside air sensor 17 is a temperature sensor that detects the air temperature outside the passenger compartment. The water temperature sensor 18 is a temperature sensor that detects the temperature of engine cooling water (heat source hot water). The temperature setter 19 is a switch for setting a set temperature test in the passenger compartment.

  Next, position control of the air mix door, which is a feature of the present embodiment, will be described with reference to FIGS.

  FIG. 3 is a flowchart showing door position control of the air mix door 6, and FIG. 4 is a flowchart showing details of normal control processing in FIG. In the position control of the air mix door 6 of the present embodiment, as shown in FIG. 4, the normal operation range ht, the upper limit position, and the lower limit position are set in the operable range Ha.

  The door position control is activated when the ignition switch IG is turned on. Hereinafter, the door position control process will be described.

  First, based on the output voltage pt of the potentiometer 12a, it is determined whether or not the output voltage pt of the potentiometer 12a is higher than the upper limit threshold value, thereby determining whether or not the position of the air mix door 6 is located above the upper limit position. Is determined (step S100).

  When the output voltage pt of the potentiometer 12a is higher than the upper limit threshold, it is determined as YES in step S100, assuming that the position of the air mix door 6 is located above the upper limit position.

  Moreover, when the position of the air mix door 6 is located below the upper limit position, it is determined as NO and the process proceeds to step S110. Here, by determining whether or not the output voltage pt of the potentiometer 12a is lower than the lower limit threshold based on the output voltage pt of the potentiometer 12a, the position of the air mix door 6 is positioned below the lower limit position. It is determined whether or not. When the position of the air mix door 6 is located above the lower limit position, NO is determined.

  At this time, assuming that the position of the air mix door 6 is normal, normal control (step S130) is performed.

  Further, when it is determined in step S100 that the position of the air mix door 6 is located above the upper limit position, and when it is determined in step S110 that the position of the air mix door 6 is located below the lower limit position, the air mix It is determined that the position of the door 6 is abnormal.

  At this time, the process proceeds to step S120, the servo motor 12 is driven, the position of the air mix door 6 is returned to the position detectable range of the potentiometer 12a, and normal control (step S130) is performed. In the present embodiment, the position detectable range of the potentiometer 12a is set between the upper limit position and the lower limit position.

  Next, details of the normal control will be described with reference to FIG.

  First, the required blowing temperature TAO is calculated based on the output signals from the sensors 16, 17 and the temperature setting device 19, and the target position of the air mix door 6 is determined based on the required blowing temperature TAO and the output signal from the water temperature sensor 18. Calculate (step S200).

  Next, the servo motor 12 is driven to bring the position of the air mix door 6 closer to the target position (step S210). Thereafter, based on the output voltage of the potentiometer 12a, it is determined whether or not the current position of the air mix door 6 matches the target position (step S220).

  When the current position of the air mix door 6 does not coincide with the target position, it is determined as NO, the process proceeds to step S230, and the position of the air mix door 6 is above the upper limit position based on the output voltage pt of the potentiometer 12a. It is determined whether or not it is located.

  At this time, when the position of the air mix door 6 is located below the upper limit position, it is determined as NO and the process proceeds to step S240. Here, based on the output voltage pt of the potentiometer 12a, it is determined whether or not the position of the air mix door 6 is located below the lower limit position. When the position of the air mix door 6 is located above the lower limit position, NO is determined.

  Thereafter, the process returns to step S210, and unless the position of the air mix door 6 exceeds the upper limit position and the lower limit position, steps S210, S220, S230, S240 are repeated, and if the current position of the air mix door 6 matches the target position, It is determined YES in S220. Thereafter, the process proceeds to step S260, the servo motor 12 is stopped, and the process returns to step S200.

  On the other hand, when the position of the air mix door 6 is located above the upper limit position in step S230, it is determined as YES. In this case, the process proceeds to step 250, and the servo motor 12 is stopped on the assumption that the position of the air mix door 6 is abnormal.

  Moreover, in step S240, when the position of the air mix door 6 is located below the lower limit position, it is determined as YES. In this case, the process proceeds to step 250, and the servo motor 12 is stopped on the assumption that the position of the air mix door 6 is abnormal.

  In this way, assuming that the position of the air mix door 6 is abnormal, the servo motor 12 is stopped and disabled.

  As described above, according to the present embodiment, when it is determined that the position of the air mix door 6 is abnormal based on the output voltage pt of the potentiometer 12a during startup (step S100), the servo motor 12 is driven. Then, the position of the air mix door 6 is returned to within the position detectable range of the potentiometer 12a, and normal control (step S130) is performed.

  Therefore, even if the position of the air mix door 6 becomes abnormal during normal control before activation and the servo motor 12 becomes inoperable, if the servo motor 12 has not failed, it can be restored at the time of activation. it can. For this reason, when there is no failure in the servo motor 12 or the like, it can be easily restored.

(Other embodiments)
In the above-described embodiment, an example in which plate doors are used as the doors 2, 6, 9a, 9b, and 9c has been described. Instead, rotary doors, sliding doors, and the like are used as the doors 2, 6, 9a, 9b, and 9c. Other doors may be used.

  In the above-described embodiment, the servo motor system of the present invention is applied to the position control of the air mix door 6, but instead of this, the position control of other doors such as the inside / outside air switching door and the mode door is performed. You may apply.

  In the above-described embodiment, an example in which the potentiometer 12a that changes the voltage output corresponding to the rotation angle of the rotation shaft of the servo motor 12 (that is, the position of the air mix door 6) is described as the position detection means of the present invention. However, instead of this, an encoder type potentiometer that outputs a pulse signal each time the rotation shaft of the servo motor 12 rotates by a certain angle may be used as the position detection means of the present invention.

  In the above-described embodiment, an example in which the servo motor system of the present invention is applied to a vehicle air conditioner has been described.

It is a schematic diagram which shows the structure of one Embodiment of the air conditioner for vehicles with which the servomotor system of this invention is applied. It is a schematic diagram which shows the electrical structure of the link mechanism of an air mix door in FIG. 1, and a vehicle air conditioner. It is a flowchart which shows the control processing of the air-conditioner ECU in FIG. It is a flowchart which shows the detail of the step in FIG. It is a figure which shows the door operable range of an air mix door.

Explanation of symbols

2, 6, 9a, 9b, 9c ... door, 6a ... support shaft, 10 ... air conditioner ECU, 11, 12, 13 ... servo motor, 16 ... inside air sensor, 17 ... outside air sensor,
18 ... Water temperature sensor, 19 ... Temperature setter, 131 ... Link lever,
130: Link pin, 140: Link member.

Claims (3)

An electric motor (12) for driving the movable member;
Detection means (12a) for detecting the position of the movable member;
Motor control means (S130) for controlling the electric motor so as to bring the position of the movable member closer to the target position within the normal operating range based on the detection position of the detection means;
Determination means (S230, S240) for determining whether or not the position of the movable member exceeds a limit position out of the normal operating range based on a detection position of the detection means;
Servo provided with motor inoperable means (S250) for disabling the operation of the electric motor on the assumption that the position of the movable member is abnormal when the determining means determines that the position of the movable member exceeds the limit position. A motor system,
When the determination means determines that the position of the movable member is abnormal at the start-up, the start of returning the position of the movable member within the detectable range of the detection means without performing the motor inoperable means A servo motor system comprising control means (S120). The limit position is set as the upper limit position above the normal operation range,
The limit position is set as a lower limit position below the normal operation range,
When the position of the movable member is higher than the upper limit position and when the position of the movable member is lower than the lower limit position, the determination means is 2. The servo motor system according to claim 1, wherein a position is determined to exceed the limit position. The servo motor system according to claim 1 or 2,
An indoor air conditioning case (1) for ventilating the passenger compartment,
The vehicle air conditioner, wherein the movable member is a door (6) disposed in the indoor air conditioning case and supported so as to be displaceable.

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