This application claims priority to Japanese Patent Application No. JP2015-175636, filed on Sep. 7, 2015, of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to motor actuators for use in in-vehicle systems or the like, methods of processing motor actuators, and methods of inspecting motor actuators.
2. Description of the Related Art
A motor actuator (hereinafter, referred to as an actuator) is used as a driving source for a door of an air conditioning apparatus, a power window, or the like in an in-vehicle system. An actuator includes an electric motor, an output shaft rotationally driven by the electric motor, a rotation sensor for detecting the rotational position of the output shaft, and a control portion for controlling the electric motor (see Reference (1) in the following Related Art List). The control portion controls the electric motor in accordance with an operation instruction transmitted from an electronic control portion (ECU) so that the rotational position detection value output from the rotation sensor approaches a target value.
(1) Japanese Unexamined Patent Application Publication No. 2013-183554.
In this type of in-vehicle systems, a plurality of actuators are controlled integrally by the ECU. In such an in-vehicle system, serial communication, such as Local Interconnect Network (LIN), may be used in order to reduce the number of electric wires for connecting the plurality of actuators. In this serial communication, data is exchanged between the plurality of actuators and the ECU with the use of a single communication line.
After an actuator is assembled, the actuator may need to be inspected in order to check the output characteristics of the rotation sensor. This inspection is carried out, for example, by measuring the signal level of a detection signal that is output from the rotation sensor during the rotational position of the output shaft being changed. Therefore, when the output characteristics of the rotation sensor are inspected, a detection signal of the rotation sensor needs to be taken out from the actuator to the outside.
When a detection signal is to be taken out from the actuator having the aforementioned serial communication function, a conceivable technique is to output a detection signal through a communication line with the use of a communication protocol for the serial communication used by the actuator. However, with this type of communication protocol for the serial communication, a detection signal can be output from the actuator to the outside only in a case in which an operation instruction requesting for a current detection signal is transmitted to the actuator from an external control apparatus. Thus, only an intermittent detection signal with respect to a temporal change can be taken out from the actuator, and a continuous detection signal with respect to the temporal change cannot be taken out. Accordingly, when the inspection is carried out through the above-described technique, favorable detection accuracy may be hard to obtain.
The present invention has been made in view of such a problem, and one of purposes thereof is to provide a technique by which the inspection accuracy can be increased when inspecting output characteristics of a sensor inside a housing.
An aspect of the present invention for solving the above-described problem provides a motor actuator. The motor actuator includes a housing that contains a motor, a sensor contained in the housing, and a transmission path capable of continuously transmitting a detection signal generated by the sensor. The housing has an insertion hole formed therein, and the insertion hole is capable of receiving a probe for taking out the detection signal from the transmission path.
According to this aspect, the detection signal of the sensor can be directly taken out from the transmission path through the probe. Accordingly, the detection signal of the sensor can be measured continuously with respect to a temporal change, and the accuracy in inspecting the output characteristics of the sensor can be increased.
The invention will now be described by reference to the preferred embodiments. This does not intend to limit the scope of the present invention, but to exemplify the invention.
Hereinafter, in embodiments and modifications, identical constituent elements are given identical reference characters, and duplicate descriptions thereof will be omitted. In addition, in each of the drawings, constituent elements are partially omitted as appropriate for simplifying the description.
The overview of the inspection method will be described. In the inspection method, a probe 202 of the inspection apparatus 200 is inserted into a probe insertion hole 14 formed in a housing 12 of the actuator 10. A transmission path capable of continuously transmitting a detection signal generated by a sensor is disposed inside the housing 12, and the leading end portion of the probe 202 makes contact with a conductor constituting a portion of the transmission path. The detection signal of the sensor can be directly taken out from the probe 202, and the detection signal of the sensor can be measured continuously by a measuring device 210 of the inspection apparatus 200.
As illustrated in
The inspection apparatus 200 further includes the probe 202 for taking out a detection signal (described later) generated by a rotation sensor 22 (described later) of the actuator 10, and the measuring device 210 for measuring the signal level of the detection signal output from the probe 202. The measuring device 210 is a voltmeter that measures the voltage level of the detection signal output from the probe 202. The measuring device 210 measures, as the voltage level, a potential difference of the detection signal relative to the ground potential.
The actuator 10 will now be described.
The actuator 10 includes the housing 12. The housing 12 is formed of a resin material. The housing 12 contains internal components, such as an electric motor 16, the rotation sensor 22, and a control circuit board 26, which will be described later.
The housing 12 is constituted by an upper housing member 12A (first housing member) and a lower housing member 12B (second housing member). Each of the housing members 12A and 12B has a shape obtained by dividing the housing 12 in a height direction Z. The height direction Z corresponds to the axial direction of an output shaft 20, which will be described later. The housing members 12A and 12B are detachably attached to each other through a snap-fit method or the like.
As illustrated in
As illustrated in
As illustrated in
Three sensor terminals 24a-24c are connected to the sensor board 22b. The sensor terminals 24a-24c include a ground sensor terminal 24a that serves as a ground potential, a power-supply sensor terminal 24b for applying a sensor driving voltage to the detection pattern 22a, and an output sensor terminal 24c for outputting a detection signal from the detection pattern 22a.
When the output shaft 20 rotates while the sensor driving voltage is being applied to the power-supply sensor terminal 24b, the position of the contact point between the brush 22c and the detection pattern 22a changes, and a voltage signal whose magnitude varies in accordance with the rotational position of the output shaft 20 is output from the output sensor terminal 24c. This voltage signal constitutes a detection signal that indicates the rotational position of the output shaft 20. In this manner, the rotation sensor 22 has a function of generating a detection signal that indicates the rotational position of the output shaft 20 and outputting the detection signal through the output sensor terminal 24c. The rotation sensor 22 of this type is well known, and thus detailed description thereof will be omitted in the present specification.
As illustrated in
Three connector terminal 28a, 28b, and 28c are connected to the control board 26. The connector terminals 28a-28c include a ground connector terminal 28a that serves as a ground potential and a power-supply connector terminal 28b for supplying power from the external control device 206. In addition, the connector terminals 28a-28c include a communication connector terminal 28c that constitutes a portion of the communication path for transmitting and receiving data to and from the external control device 206.
As illustrated in
An IC chip 34 serving as a circuit element is mounted to the control board 26. The IC chip 34 serves as a circuit element that constitutes a communication portion 36 for communicating with the external control device 206 and the control portion 38 for controlling the electric motor 16 and the rotation sensor 22.
The communication portion 36 transmits and receives data to and from the external control device 206 through serial communication (multiplex communication) with the use of the single communication line 208c in accordance with a predetermined communication protocol. In this communication protocol, a master-slave communication system is used. In this communication system, the external control device 206 is the master and the actuator 10 is the slave. Under this communication protocol, the control portion 38 of the actuator 10 operates in accordance with an operation instruction transmitted from the external control device 206. This communication protocol is, for example, Local Interconnect Network (LIN) or Controller Area Network (CAN).
Upon being supplied with power from the external control device 206, the control portion 38 generates a motor driving voltage and supplies the motor driving voltage to the electric motor 16, and generates a sensor driving voltage and supplies the sensor driving voltage to the rotation sensor 22.
In addition, the control portion 38 controls the electric motor 16 in accordance with a rotational operation instruction, transmitted from the external control device 206, for rotating the electric motor 16. Specifically, the control portion 38 controls the direction in which the electric motor 16 rotates and the number of rotations of the electric motor 16 so that the rotational position detection value indicated by the detection signal output from the rotation sensor 22 approaches the rotational position instruction value included in the rotational operation instruction transmitted from the external control device 206.
The control portion 38 receives an analog-value detection signal from the rotation sensor 22 through a transmission path 48 (described later). The control portion 38 subjects the analog-value detection signal to predetermined processing including A/D conversion processing and acquires a digital-value detection signal. The control portion 38 carries out the control of the electric motor 16 and so on with the use of the digital-value detection signal.
As illustrated in
The conductor patterns 42 and 44 include a transmission pattern 44 that constitutes a portion of the transmission path 48 capable of continuously transmitting a detection signal generated by the rotation sensor 22. The transmission path 48 is constituted by the output sensor terminal 24c of the rotation sensor 22 and the transmission pattern 44, and an analog-value detection signal generated by the rotation sensor 22 is transmitted to the transmission path 48. The transmission pattern 44 provides electrical continuity between the output sensor terminal 24c of the rotation sensor 22 and the IC chip 34.
The transmission pattern 44 includes a primary transmission pattern 44a that constitutes a portion of a primary transmission path for transmitting a detection signal from the rotation sensor 22 (from the through-hole electrode 46 in
A linear portion 44ba having a substantially constant pattern width and a probe abutting portion 44bb at the leading end portion of the auxiliary transmission pattern 44b are formed in the auxiliary transmission pattern 44b. The probe abutting portion 44bb is provided to facilitate abutting of the leading end portion of the probe 202 and is formed to have a greater width than the linear portion 44ba, which is the other portion adjacent to the probe abutting portion 44bb in the auxiliary transmission path. In the present embodiment, the probe abutting portion 44bb is formed in a circular shape. In this manner, the auxiliary transmission pattern 44b is used to allow the probe 202 to make contact therewith.
The probe insertion hole 14 will now be described.
As illustrated in
On the front side surface portion 12a of the housing 12, a convex portion 14b is formed at a peripheral portion 14a of the probe insertion hole 14. The convex portion 14b is formed in a cylindrical shape that projects from the housing 12 toward the outside, and the inner side of the convex portion 14b forms a portion of the probe insertion hole 14. On the front side surface portion 12a of the housing 12, a concave portion 14c is formed around the root portion of the convex portion 14b that is on the side opposite to the direction in which the convex portion 14b projects. The concave portion 14c is dented in the direction opposite to the direction in which the convex portion 14b projects. The concave portion 14c is formed in a continuous annular groove shape that surrounds the root portion of the cylindrical convex portion 14b. The effects of the convex portion 14b and the concave portion 14c will be described later.
The probe abutting portion 44bb on the control board 26 described above is disposed at a position that is inside the housing 12 and that is disposed on a straight line La passing through the center axis of the probe insertion hole 14 so as to facilitate abutting of the probe 202. In other words, the probe abutting portion 44bb is disposed on the inner side of the housing 12 relative to the probe insertion hole 14. When viewed from another perspective, the probe abutting portion 44bb, which constitutes a portion of the transmission path 48, is disposed at a position at which the leading end portion of the probe 202 inserted in the probe insertion hole 14 can abut.
The probe abutting portion 44bb is shaped such that, as viewed from one side in the axial direction of the probe insertion hole 14, an outline 14d of a cross-sectional shape of the probe insertion hole 14 orthogonal to the axial direction is fit inside an outline 44c of a surface shape of the probe abutting portion 44bb. This configuration makes it easier to dispose the probe abutting portion 44bb on the straight line La passing through the center axis of the probe insertion hole 14 even when an error, such as a dimension error or an assembly error, of the housing 12 or the like is present, and the probe 202 can be made to stably abut against the probe abutting portion 44bb with ease.
Now, an inspection method in which the above-described actuator 10 is used will be described.
This inspection is carried out for an assembled actuator 10. The assembled actuator 10″ as used herein refers to an actuator 10 obtained by containing the internal components, such as the electric motor 16, in the lower housing member 12B and then attaching the upper housing member 12A to the lower housing member 12B as illustrated in
As illustrated in
The operator inserts the probe 202 into the probe insertion hole 14 of the housing 12 and brings the leading end portion of the probe 202 into contact with the probe abutting portion 44bb on the control board 26. Thus, the probe abutting portion 44bb of the actuator 10 and the probe 202 become having electrically continuity, and the probe abutting portion 44bb and the measuring device 210 become electrically connected through the probe 202.
The operator operates the external control device 206 to supply power from the external control device 206 to the electric motor 16 and the rotation sensor 22 through the control board 26. In addition, the operator operates the external control device 206 to transmit a rotational operation instruction for rotating the electric motor 16 from the external control device 206. Thus, the control portion 38 of the actuator 10 causes the electric motor 16 to operate in accordance with the rotational operation instruction so as to rotationally drive the output shaft 20.
While the output shaft 20 rotates, a detection signal generated by the rotation sensor 22 is continuously transmitted to the transmission path 48 including the auxiliary transmission pattern 44b. The detection signal continuously transmitted to the auxiliary transmission pattern 44b is continuously taken out to the measuring device 210 through the probe 202 from the probe abutting portion 44bb. Thus, the signal level of the detection signal can be measured continuously by the measuring device 210. The operator checks a temporal change in the signal level of the detection signal, and thus the output characteristics of the rotation sensor 22 can be inspected. At this time, the probe 202 takes out an analog-value detection signal generated by the rotation sensor 22, and the output characteristics of the rotation sensor 22 are inspected with the use of the analog-value detection signal. The measuring device 210 is provided with a display portion (not illustrated), such as gradations or the like, that displays the measurement result, and the operator can check the signal level of the detection signal through the content displayed on the display portion.
The effects of the actuator 10 and the inspection method described above will be described.
(A) In the actuator 10 according to the present embodiment, the probe insertion hole 14 that can have the probe 202 inserted thereinto is formed in the housing 12. Thus, the detection signal of the rotation sensor 22 can be directly taken out from the transmission path 48 through the probe 202. Accordingly, the detection signal of the rotation sensor 22 can be measured continuously with respect to a temporal change, and the accuracy in inspecting the output characteristics of the rotation sensor 22 can be increased, as compared to a case in which the detection signal is measured intermittently with respect to a temporal change, as illustrated in
(B) Consider a case in which the detection signal is taken out by transmitting an operation instruction requesting for a current detection signal from the external control device to the control portion 38 of the actuator 10, as described above. In this case, a method can be contemplated in which the number of measurement points is increased by increasing the number of transmitting the operation instruction in order to improve the inspecting accuracy of the output characteristics of the rotation sensor 22. However, in this case, increasing the number of transmitting the operation instruction causes increasing the number of processes required for the instruction operation, and an extended period of time is required for the inspection operation. In this respect, with the actuator 10 according to the present embodiment, the detection signal of the rotation sensor 22 can be measured continuously. Accordingly, the number of processes and the time required for the inspection operation can be reduced by reducing the number of transmitting the operation instruction from the external control device 206, and the accuracy for inspecting the output characteristics of the rotation sensor 22 can be improved.
In addition, the probe insertion hole 14 is formed in the housing 12 at a position different from the position where the connector portion 12g is formed. Thus, even if the probe insertion hole 14 is plugged up after the inspection operation is finished as described later, the external connector 204 can be detachably mounted to the connector portion 12g.
(C) The probe abutting portion 44bb is formed in the conductor pattern 44 that constitutes a portion of the transmission path 48, which makes it easier to have the leading end portion of the probe 202 inserted in the probe insertion hole 14 abut against the conductor pattern 44. Accordingly, an operation of bringing the probe 202 into contact with the conductor pattern 44 is facilitated, and the operability of the inspection operation improves.
(D) The probe abutting portion 44bb is formed in the conductor pattern 44 on the control circuit board 26, and thus a broader area can easily be secured for the probe abutting portion 44bb than in a case in which the probe abutting portion 44bb is formed in a terminal, such as the output sensor terminal 24c, that constitutes a portion of the transmission path 48. Accordingly, an operation of bringing the probe 202 into contact with the probe abutting portion 44bb is facilitated, and the operability of the inspection operation improves.
(E) The transmission path 48 includes, in addition to the primary transmission pattern 44a, the auxiliary transmission pattern 44b into which the probe 202 is brought into contact. Accordingly, the primary transmission pattern 44a does not need to make contact with the probe 202, and the inspection operation can be carried out by using the auxiliary transmission pattern 44b while the primary transmission pattern 44a is being protected from making contact with the probe 202.
In addition, consider a modification in which the probe insertion hole 14 is formed in the right side surface portion 12c (see
In contrast, according to the present embodiment, the connector portion 12g and the probe insertion hole 14 are formed in the front side surface portion 12a of the housing 12. Accordingly, when the external connector 204 and the probe 202 are inserted into the connector portion 12g and the probe insertion hole 14, respectively, the operation can be carried out while the housing 12 is held from the same position (the back side surface portion 12b of the housing 12), and the operability of the inspection operation improves.
A method of processing the above-described actuator 10 will now be described.
If the probe insertion hole 14 of the actuator 10 is left open after the inspection operation described above finishes, a foreign object, such as dust, may enter the housing 12 through the probe insertion hole 14 and affect the operation of the internal components in the housing 12.
Therefore, in the processing method, as illustrated in
According to this processing method, the probe insertion hole 14 of the housing 12 can be plugged up by the plugging body 50, and thus the internal components in the housing 12 can be protected from a foreign object, such as dust. In addition, the plugging body 50 is formed integrally with the peripheral portion of the probe insertion hole 14 in the housing 12, and thus a dedicated component for the plugging body 50 is not necessary. Accordingly, the number of components of the actuator 10 can be reduced, and thus the manufacturing cost can be reduced while the management of the components is simplified.
The convex portion 14b is formed at the peripheral portion of the probe insertion hole 14 of the housing 12, and thus the amount of material for plugging up the probe insertion hole 14 can be secured with ease. Accordingly, the probe insertion hole 14 can be plugged up by melting the peripheral portion 14a of the probe insertion hole 14 while the peripheral portion 14a of the probe insertion hole 14 is prevented from becoming excessively thin. It should be noted that, when the probe insertion hole 14 is to be plugged up, the convex portion 14b that constitutes a portion of the peripheral portion 14a of the housing 12 is heated and melted, and the resulting molten resin is made to flow into the probe insertion hole 14.
In addition, the concave portion 14c is formed in the front side surface portion 12a of the housing 12 at a portion surrounding the root portion of the convex portion 14b, and thus this configuration provides the following advantage. Consider a case in which the convex portion 14b is melted and the molten resin is made to flow into the probe insertion hole 14. In this case, the concave portion 14c serves a function of accepting the molten resin that is to flow around the probe insertion hole 14 instead of flowing into the probe insertion hole 14. This configuration can reduce the molten resin broadly spreading around the probe insertion hole 14 on the outer surface of the housing 12 and can make the appearance of the melted portion less noticeable after the probe insertion hole 14 is plugged up.
Although
The first embodiment describes an example in which an insertion hole into which the probe 202 is inserted is the probe insertion hole 14. The present embodiment differs from the first embodiment in that an insertion hole into which the probe 202 is inserted is the connector insertion hole 12h. Inside the housing 12, the control board 26 and the probe abutting portion 44bb of the auxiliary transmission pattern 44b that constitutes a portion of the transmission path 48 is disposed on the inner side of the housing 12 relative to the connector insertion hole 12h.
In addition to the ground line 208a, the power-supply line 208b, and the communication line 208c, the probe 202 is inserted into the external connector 204 of the inspection apparatus 200. The lines 208a-208c are omitted in
Thus far, the present invention has been described on the basis of the embodiments, but the embodiments merely describe the principle and the applications of the present invention. In addition, a number of modifications or arrangement changes can be made to the embodiments within the scope that does not depart from the spirit of the present invention set forth in the claims.
The actuator 10 may be used in an in-vehicle system, such as a vehicular air conditioning apparatus or a power window, or may be used for a purpose other than a vehicle. The electric motor 16 may be an AC motor, a servomotor, a stepping motor, or the like, instead of a DC motor. An example in which the control portion 38 and the communication portion 36 on the control board 26 are constituted by a single circuit element (IC chip 34) has been described. Alternatively, the control portion 38 and the communication portion 36 may be constituted by separate circuit elements.
An example in which the rotation sensor 22 is constituted by a potentiometer has been described. Alternatively, the rotation sensor 22 may be constituted by a rotary encoder or the like. In addition, although an example in which a sensor to be inspected is the rotation sensor 22 has been described, this is not a limiting example. For example, a sensor to be inspected may be a temperature sensor, a pressure sensor, a humidity sensor, or the like. In any case, a sensor to be inspected may be a sensor that detects a physical quantity.
An example in which the transmission path 48 capable of continuously transmitting a detection signal generated by the sensor includes the conductor patterns 42 and 44 on the control circuit board 26 has been described. The transmission path 48, however, is not limited to the conductor patterns and may be a terminal of the output sensor terminal 24c. This terminal is a molding made of conductor. When the transmission path 48 is a terminal, the probe abutting portion 44bb having a greater width than a portion of the terminal may be formed in adjacent to that portion. When the transmission path 48 is a terminal as well, a primary transmission path and an auxiliary transmission path may be formed. An example in which the transmission path 48 is formed outside the sensor has been described. Alternatively, the transmission path 48 may be formed inside the sensor. An example in which the probe abutting portion 44bb is formed at the leading end portion of the auxiliary transmission path has been described. Alternatively, the probe abutting portion 44bb may be formed at a position midway in the auxiliary transmission path or may be formed in the primary transmission path.
The measuring device 210 may be equipped with a function of carrying out determination processing of determining whether the signal level of a detection signal is within a predetermined range. In this case, the processing result of the determination processing may be displayed in the display portion of the measuring device 210, and thus the operator can check the signal level of the detection signal.
In the third embodiment, an example in which the probe 202 is inserted into the external connector 204 of the inspection apparatus 200 and the leading end portion of the probe 202 is brought into contact with the auxiliary transmission pattern 44b on the control board 26 so as to take out the detection signal of the sensor has been described. Aside from this configuration, a detection signal terminal for taking out a detection signal may be connected to the control board 26 or the like along with the other connector terminals 28a-28c, and the probe 202 in the external connector 204 may be brought into contact with this detection signal terminal so as to take out the detection signal of the sensor. In this case, the detection signal terminal constitutes a portion of the transmission path capable of continuously transmitting a detection signal of the sensor. In addition, to bring the detection signal terminal and the probe 202 in the external connector 204 into contact with each other, one of the two may be formed as a male terminal and the other one may be formed as a female terminal, and the two may be fitted together to retain their positions.
Number | Date | Country | Kind |
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2015-175636 | Sep 2015 | JP | national |