JP2009044888A - Actuator, and sensor characteristic correction method for actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator and a sensor characteristic correction method for an actuator that enable improvement in output accuracy of an actuator while allowing an assembly error or a difference in mechanical characteristics between individual actuators to be corrected as a further ideal sensor characteristic when attaching a sensor to an actuator. <P>SOLUTION: The actuator 100 is mounted with a sensor 113. The sensor is composed so that the sensor characteristics can be rewritten after attachment to the actuator. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an actuator equipped with a sensor and a method for correcting sensor characteristics of the actuator.

  An actuator that converts rotational motion of a motor or the like into linear motion and linearly moves the drive shaft is known (for example, see Patent Document 1 below). For example, when a sensor for detecting the rotation angle is attached to the shaft of the actuator to control the position of the drive shaft, accurate rotation angle detection is required.

When attaching a sensor for detecting the rotation angle of a shaft to the actuator as described above, conventionally, according to the standard of the actuator and the sensor, a human hand or a mounting jig is used so that the positional relationship of the actuator matches. It was attached. Also, in order to improve the sensor detection accuracy, noise countermeasure components are inserted in order to reduce noise from the outside of the sensor, or the sensor is arranged at a location far from the noise source.
JP-A-10-051996

  When the sensor is attached to the actuator with a human hand or using an attachment jig as in the above-described prior art, the positional relationship between the sensor and the actuator is shifted depending on the ability of the human hand or the attachment jig. Therefore, the positional accuracy of the sensor may deteriorate at the time of assembly. In addition, because there is a difference in mechanical characteristics (linearity error due to ball screw lead pitch error, gear train backlash, etc.) for each actuator, the sensor characteristics differ from actuator to actuator, and there is rattling in the actuator. In this case, there is a possibility that the amount of variation has a certain variation as a sensor mounting error, and the position accuracy of the actuator drive shaft may be further deteriorated.

  Furthermore, in order to improve the sensor detection accuracy and improve the drive shaft position accuracy, inserting noise countermeasure parts into the sensor against external noise will lead to an increase in cost and interference with other parts of the system Due to layout restrictions, a difficult problem may arise where it is necessary to install the sensor at a position far from the noise source.

  In the present invention, in view of the above-described problems of the prior art, when a sensor is attached to an actuator, assembly errors and differences in mechanical characteristics of individual actuators can be corrected as more ideal sensor characteristics, and the output accuracy of the actuator can be improved. It is an object of the present invention to provide an actuator that can be improved and a sensor characteristic correction method for the actuator.

  In order to achieve the above object, an actuator according to the present invention is an actuator on which a sensor is mounted, and the sensor characteristics can be rewritten after being attached to the actuator.

  According to this actuator, since the sensor characteristics can be rewritten after the sensor is attached to the actuator, the assembly error and the difference in mechanical characteristics of each actuator can be corrected as a more ideal sensor characteristic. The output accuracy of the actuator (for example, the position accuracy of the drive shaft) can be improved. The sensor characteristic is, for example, the relationship between the actuator output (for example, the moving amount of the drive shaft) and the sensor output.

  Means for operating the actuator in the actuator and measuring its movement amount and sensor output to obtain output data; means for calculating ideal sensor characteristics based on the output data and sensor characteristics before rewriting; The sensor characteristics can be rewritten by providing means for rewriting the sensor characteristics with the calculated sensor characteristics.

  In this case, it is possible to rewrite the sensor characteristics more ideal by approximating the sensor characteristics with the median value of the actuator obtained from the output data.

  That is, the output data obtained by reciprocating the actuator is approximated by a least square method to approximate a straight line passing through the median value of the actuator, and the straight line is approximated to a line of ideal sensor characteristics. Therefore, it is preferable to rewrite the sensor characteristics by approximating them with the median value of the above.

  For example, when the actuator has backlash due to gear backlash, etc., the mechanical characteristics are approximated by approximating the output data obtained by reciprocating driving to a straight line passing through the median value of the backlash by approximating by the least square method. The sensor characteristics can be approximated by a straight line, and by approximating the straight line to the ideal sensor characteristic line, the sensor characteristic can be approximated to the ideal sensor characteristic and rewritten by the median value of the backlash. .

  In addition, by attaching a conductive plate so as to surround the sensor, the conductive plate functions as a magnetic shielding plate, and the influence of external noise can be reduced by a so-called shielding effect, and the detection accuracy of the sensor is improved. This improves the output accuracy of the actuator.

  Further, the sensor characteristics can be rewritten by providing a memory element that can store and rewrite the sensor characteristics.

  Moreover, the said actuator can be used as a positioning actuator for the gear shift of a ship's forward / reverse switching.

  The sensor characteristic correction method for an actuator according to the present invention is a sensor characteristic correction method for rewriting and correcting a sensor characteristic after mounting the sensor in an actuator on which the sensor is mounted. Measuring output and obtaining output data; calculating ideal sensor characteristics based on the output data and sensor characteristics before rewriting; and rewriting the sensor characteristics to the calculated sensor characteristics .

  According to this sensor characteristic correction method of an actuator, the sensor characteristic can be rewritten after the sensor is attached to the actuator, so that an assembly error and a difference in mechanical characteristic of each actuator can be corrected as a more ideal sensor characteristic. Thus, the output accuracy of the actuator can be improved.

  Further, by measuring the backlash of the actuator from the output data and approximating and rewriting the sensor characteristic with the median value of the backlash, it can be rewritten to a more ideal sensor characteristic.

  Further, by approximating the output data obtained by reciprocating the actuator by the least square method, the actuator approximates a straight line passing through the median value of the actuator, and approximating the straight line to the ideal characteristic straight line. It is preferable to rewrite the sensor characteristic by approximating the median value.

  According to the actuator and the sensor characteristic correction method of the present invention, when a sensor is attached to the actuator, it is possible to correct an assembly error or a difference in mechanical characteristics of each actuator as a more ideal sensor characteristic, thereby improving the output accuracy of the actuator. it can. In addition, the variation in actuator products is reduced.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an outboard motor using the actuator according to the present embodiment. FIG. 2 is a front view of the actuator according to the present embodiment. FIG. 3 is a view of the actuator of FIG. 2 as viewed in the direction of arrow III. FIG. 4 is a view of the configuration of FIG. 3 taken along line IV-IV and viewed in the direction of the arrow.

  In FIG. 1, the outboard motor 2 has a casing 2a fixed to the hull 1 and a cowling 2b attached to the upper portion thereof. An engine (not shown) in which the output shaft 3 is extended to the casing 2a is mounted inside the cowling 2b. A bevel gear 3 a is attached to the lower end of the output shaft 3.

  A propeller shaft 4 is horizontally disposed below the casing 2a and is rotatably supported. In the figure of the propeller shaft 4, the right end side protrudes outward from the casing 2 a, and the propeller 5 is attached to the end portion.

  The propeller shaft 4 passes through a forward bevel gear 6 and a reverse bevel gear 7 that mesh with the bevel gear 3 a, and a dog clutch 8 is disposed between the bevel gears 6 and 7. The dog clutch 8 can move relative to the propeller shaft 4 in the axial direction but can rotate integrally, and the bevel gears 6 and 7 can rotate relative to each other. Although not shown, the dog clutch 8 has protrusions facing in both axial directions. When the dog clutch 8 moves to the left in the figure, the protrusion engages with the concave portion of the bevel gear 6, and the dog clutch 8 and the bevel gear 6. And rotate together. On the other hand, by moving to the right in the figure, the protrusion engages with the concave portion of the bevel gear 7, and the dog clutch 8 and the bevel gear 7 rotate integrally.

  The dog clutch 8 is driven in the axial direction by a cam shaft 9. The cam shaft 9 is coupled so as to be displaced in the axial direction in accordance with the rotation of the operation shaft 10. The operation shaft 10 is connected to the drive shaft 117 of the actuator 100 via the link member 11.

  In FIG. 4, a cylindrical housing 101 of the actuator 100 includes an aluminum housing main body 101A, a resin or metal cover member 101B assembled to the end surface of the housing by a bolt B (FIG. 3), and a motor bracket. 101C. The housing body 101A has a motor chamber 101a and a screw shaft chamber 101b. A motor 102 is disposed in the motor chamber 101a. The motor 102 is fixed to a plate-shaped motor bracket 101C. The motor bracket 101C sandwiches an outer ring of a ball bearing 114 described later between the housing main body 101A and the motor chamber 101a of the housing main body 101A and the screw shaft chamber. It is attached so as to block 101b.

  A rotating shaft 102a of the electric motor 102 protrudes from the motor bracket 101C, and a metal first gear 103 is attached to the end of the rotating shaft 102a so as not to be relatively rotatable by press-fitting. A resin-made second gear 105 is rotatably disposed around the long shaft 104 implanted in the motor bracket 101C, and meshes with the large gear portion 106a of the first gear 103 and the third gear 106. Yes.

  The resin-made third gear 106 has a large gear portion 106a and a small gear portion 106b formed coaxially, and is attached to the end of the screw shaft 107 so as not to be relatively rotatable by serration coupling. A support member 108 is attached to the motor bracket 101C so as to cover a part of the third gear 106. Here, the first gear 103, the second gear 105, and the third gear 106 constitute a first power transmission mechanism.

  A fourth gear 109 disposed adjacent to the second gear 105 is rotatably supported around the long shaft 104. The resin-made fourth gear 109 has a large gear portion 109 a meshed with the small gear portion 106 b of the third gear 106 and a small gear portion 109 b formed coaxially.

  The small gear portion 109 b of the fourth gear 109 meshes with the large gear portion 111 a of the fifth gear 111 that is rotatably supported with respect to the short shaft 110 implanted in the support member 108 in parallel with the long shaft 104. ing. The resin-made fifth gear 111 has a large gear portion 111a and a small gear portion 111b formed coaxially. The small gear portion 111 b meshes with a sixth gear 112 that is disposed adjacent to the fifth gear 111 and rotatably supported around the long shaft 104. A bush for smooth rotation may be disposed between the long shaft 104 and the short shaft 110 and each gear.

  A rotation angle detection sensor 113 is attached by being arranged in the hole 101c of the cover member 101B and being fixed with a machine screw BS (FIG. 3). The measuring shaft 113a of the sensor 113 is connected to the sixth gear 112 and rotates integrally. The tip of the long shaft 104 extending in a cantilever manner is supported by the sensor 113 via the sixth gear 112 and the measurement shaft 113a. The sensor 113 can accurately detect an angle within a predetermined range (for example, 90 degrees) of the measurement axis 113a. Here, the first gear 103, the second gear 105, the third gear 106, the fourth gear 109, the fifth gear 111, and the sixth gear 112 constitute a second power transmission mechanism. The cover member 101B has a function as a gear cover for sealing so that foreign matter does not enter each gear. In addition, it is preferable to use different resin materials for the gears to be engaged with each other because wear can be suppressed.

  In FIG. 4, the screw shaft 107 is rotatably supported by a ball bearing 114 on the right end side in the drawing with respect to the housing main body 101A. The screw shaft 107 has a male screw groove 107a on the left end side.

  The screw shaft 107 passes through a cylindrical nut 115. A female screw groove 115a is formed on the inner peripheral surface of the nut 115 so as to face the male screw groove 107a, and a large number of balls 116 are formed in a spiral space (rolling path) formed by both the screw grooves 107a and 115a. It is arranged to roll freely. The nut 115 is provided with a detent (not shown) with respect to the housing main body 101A, and is relatively movable in the axial direction in the screw shaft chamber 101b, but is not relatively rotatable. A nut 115 as an axial movement element, a screw shaft 107 as a rotation element, and a ball 116 as a rolling element constitute a ball screw mechanism, and the ball screw mechanism and the following drive shaft 117 drive the ball screw mechanism. Configure the mechanism.

  The left end of the screw shaft 107 penetrates into a bag hole 117a formed in the round shaft-shaped drive shaft 117. The right end of the drive shaft 117 in the drawing is coaxially fitted to the nut 115 and connected with a pin so as to move integrally. The drive shaft 117 is supported by the bush 118 so as to be movable in the axial direction with respect to the housing body 101A, and a seal 119 is disposed on the left side (external side) of the bush 118, and the housing body 101A and the drive shaft 117 are disposed. Prevents foreign matter such as seawater and dust from entering between. A hole 117b for connecting to the link member 11 is formed at the end of the drive shaft 117 protruding from the housing main body 101A.

  In FIG. 1, the wiring 102b of the motor 102 and the wiring 113b of the sensor 113 extend to the cowling 2b side through the breather pipe 12, and are further connected to a control device (not shown).

  Next, the operation of the actuator according to the present embodiment will be described. Here, since the bevel gear 3a is always meshed with both the forward bevel gear 6 and the reverse bevel gear 7, the bevel gear 6 to which power is transmitted from the bevel gear 3a as long as the internal combustion engine is operating. , 7 are rotating in opposite directions. However, in the neutral state, as shown in FIG. 1, since the dog clutch 8 is not engaged with any of the bevel gears 6 and 7, the power of the output shaft 3 is not transmitted to the propeller shaft 4 and the propeller 5 It will not rotate.

  Here, assuming that the operator operates the shift lever (not shown) in the forward direction from the neutral state, in FIG. 4, electric power having a predetermined polarity is supplied to the motor 102, and the rotating shaft 102a is moved in the predetermined direction. Rotate. Since the rotational force of the rotating shaft 102a is transmitted to the screw shaft 107 via the first gear 103, the second gear 105, and the third gear 106, the nut 115 is moved to the left in FIG. 4 according to the rotation of the screw shaft 107. It is displaced to. When the nut 115 is displaced to the left, the drive shaft 117 moves in a protruding direction, so that the link member 11 pivots in FIG. Accordingly, the operation shaft 10 rotates in a predetermined direction, the cam shaft 9 moves to the left via a cam mechanism (not shown), and the dog clutch 8 is engaged with the forward bevel gear 6. As a result, the power of the output shaft 3 can be transmitted to the propeller shaft 4 via the bevel gears 3a and 6 and the dog clutch 8, and the propeller 5 can be rotated forward.

  On the other hand, the rotational force of the rotating shaft 102a is transmitted to the measuring shaft 113a of the sensor 113 via the first gear 103, the second gear 105, the third gear 106, the fourth gear 109, the fifth gear 111, and the sixth gear 112. Is done. A signal corresponding to the rotation of the measuring shaft 113a is input from the sensor 113 to the control device (not shown) via the wiring 113b. If it is determined that the screw shaft 107 is rotated by a predetermined rotation amount based on the signal, the control device (not shown) stops the power supply to the motor 102.

  On the other hand, when the operator operates the shift lever (not shown) in the reverse direction, in FIG. 4, the electric power having the reverse polarity is supplied to the motor 102 and the rotating shaft 102a rotates in the reverse direction. Is the reverse operation, and the drive shaft 117 of the actuator 100 moves in the retracting direction. Accordingly, the operating shaft 10 rotates in the reverse direction via the link member 11 in FIG. 1, the cam shaft 9 moves to the right via the cam mechanism (not shown), and the dog clutch 8 is engaged with the reverse bevel gear 7. Let As a result, the power of the output shaft 3 can be transmitted to the propeller shaft 4 via the bevel gears 3a and 7 and the dog clutch 8, and the propeller 5 can be rotated in the reverse direction.

  The above-described sensor 113 will be further described. The sensor 113 is a sensor that detects the magnetic field of the magnet built in the measurement shaft 113a of FIG. 4 by the Hall IC and outputs a voltage corresponding to the rotation angle of the measurement shaft 113a. The sensor output characteristics can be arbitrarily configured by writing the parameter values associated with.

  The sensor 113 embeds a measuring shaft 113a in a sensor gear configured with a reduction ratio so that a movable angle with a sufficient margin is left in the possible mechanical angle of the sensor, and is fixed at two locations by screws BS (FIG. 3). Attached.

  Regarding the reference for attaching the actuator 100 and the sensor 113, the dimension from the hole for attaching the actuator 100 to the system (outboard motor 2) to the bag hole 117a formed at the tip of the drive shaft 117 is used as a reference. The sensor 113 is fixed by two screws BS (FIG. 3) in a state in accordance with the voltage. In this case, as shown in FIG. 5, when the drive shaft 117 of the actuator 100 moves linearly, the reference point z of the bag hole 117a moves between the left and right stroke limit positions R and F in the figure, but the drive shaft 117 Is positioned so that the reference point z becomes the neutral position N, and the sensor 113 is fixed. However, conventionally, since the sensor is fixed by a human hand or an assembling jig, an assembling error occurs due to its ability.

  Further, since the influence of the mechanical characteristics (the linearity of the ball screw mechanism and the backlash / linearity of the sensor gear train in FIG. 4) remains as it is, the accuracy of the actuator 100 is caused by the backlash of the actuator 100 and the above assembly error. Deviates from the theoretical value.

  A configuration in which the sensor characteristics are rewritten after the sensor 113 is attached to the actuator 100 to correct the backlash and assembly error of the actuator will be described with reference to FIG.

  FIG. 6 is a block diagram showing a schematic configuration of a sensor characteristic rewriting device for rewriting the sensor characteristics of the sensor 113.

  The sensor characteristic rewriting device 20 in FIG. 6 detects a stroke amount of the drive shaft 117 of the actuator 100 and outputs a stroke signal h, and operates the motor 102 (FIG. 4) of the actuator 100 when the stroke signal h is input. Sensor rewrite control for reading and writing sensor characteristic data between the motor controller 22 for moving the drive shaft 117 and the sensor 113 for measuring the sensor voltage value with respect to the stroke amount obtained from the stroke signal h. Tool 24, sensor voltage value c with respect to the stroke amount measured by measuring instrument 23, and arithmetic device 25 for approximating the ideal value based on the characteristic data before rewriting acquired from sensor 113, and sensor voltage of measuring instrument 23 Switch between measurement mode and sensor characteristic data read / write mode It includes a switch 26, a.

  When the changeover switch 26 is set to the measurement mode, when the reciprocating data of the drive shaft 117 is acquired, the sensor signal g from the sensor 113 is fed back to the motor controller 22 to move the drive shaft 117.

  When the changeover switch 26 sets the characteristic data read / write mode, the sensor rewrite input signal g is input from the sensor 113 to the sensor rewrite jig 24, and the ideal value approximated by the arithmetic unit 25 is output from the sensor rewrite jig 24 to the sensor rewrite output signal. As e, the data is written to the storage element in the sensor 113 and updated.

  Next, a procedure for rewriting sensor characteristics by the sensor characteristic rewriting device 20 of FIG. 6 will be described.

  (1) The motor 102 (FIG. 4) is driven using the stroke sensor 21 of FIG. 6, and the drive shaft 117 is reciprocated for the entire stroke between the stroke limit positions R and F of FIG.

  (2) The stroke amount (movement amount) when the drive shaft 117 reciprocates and the sensor voltage from the sensor 113 are sampled, and as shown in FIG. Then, a central straight line (indicated by a broken line in FIG. 7) is calculated to obtain the following linear approximation formula (1).

VRn = AXn + B (1)
However,
VRn: n-point sensor voltage [V]
Xn: Position of drive shaft at point n [mm]
n: nth sample point A: slope in least square approximation B: intercept in least square approximation

  Of the reciprocating data of the drive shaft 117, the data of the folded portion is preferably not adopted because approximate distortion occurs due to the least square method weighting.

  (3) The calculated linear straight line approximation formula (1) and the characteristic data before rewriting are converted into position data inside the Hall IC of the sensor 113, and the arbitrary position data is converted into an ideal straight line sensor voltage value by at least two. Approximation by multiplication is performed to obtain the desired slope and intercept of the linear line. The position data inside the Hall IC corresponds to the magnetic field intensity received by the Hall IC plate, and is a digital value of the magnet rotation angle embedded in the measurement shaft 113a.

  Next, a specific method for approximating the ideal sensor characteristic with the median value of the ratchet by further approximating the approximate straight line passing through the median value of the actuator with the median value of the ideal sensor characteristic will be described. .

  The relational expression (1) between the stroke amount Xn calculated in the above (2) and the sensor voltage VRn is as follows.

      VRn = AXn + B (1)

  The slope of the straight line obtained by reading the characteristic data before rewriting the storage element of the sensor 113 with the sensor rewriting jig 24 is Xsense, and the intercept is Vp. For example, the full scale of the digital value is 2048 and the resolution is 5V (digital value 409 .6 / 1V), the position data Sn inside the Hall IC is calculated as follows, and Equation (2) is obtained using Equation (1).

From the following equation (2), the relationship between the stroke voltage Xn and the magnetic field strength received by the Hall IC plate from the magnet embedded in the measurement shaft 113a is derived from the sensor voltage VRn of equation (1) and the sensor characteristic value before rewriting. Is done.
Sn = 2048/5 {(VRn-Vp) / Xsence}
= 2048/5 {(AXn + B) -Vp} / Xsence (2)

Here, an ideal primary straight line is represented by the following equation (3).
Vn = CXn + D (3)
Vn: nth sensor voltage [V]
Xn: nth stroke value [mm]
C: Sensor voltage per mm [V]
D: Sensor voltage [V] at 0 mm position (neutral position)
The ideal straight line can be arbitrarily set in relation to the sensor voltage depending on the configuration of the actuator.

  The internal position data Sn at the n stroke positions and the sensor voltage Vn to be approximated are calculated from the equations (2) and (3) above, and are substituted into the following equation (Equation 1). calculate. (The arbitrary magnetic field of the magnet of the measuring shaft 113a is corrected to a desired arbitrary sensor voltage value.)

  The above-mentioned a and b are rewritten by the rewriting jig 24 as the sensor characteristics in which the backlash of the actuator 100 and the assembling error are corrected, and the sensor rewriting output signal f is sent to the sensor 113 and written into the internal storage element for updating.

  FIG. 8 is a graph (a) showing the sensor characteristics in relation to the stroke amount and the stroke error when the sensor characteristics are not rewritten with respect to the sensor 113 (attached state) and the median value of the backlash as described above. It is a graph (b) which shows a sensor characteristic by the relationship between the stroke amount and stroke error in the case.

  In Fig. 8 (a), there is an assembly error and rattling due to the assembly of the sensor by human hand, and the influence of mechanical characteristics (ball screw linearity, sensor gear train rattling / linearity) remains the same. The accuracy of the actuator deviates from the theoretical value due to error and actuator backlash. 8 (a) and 8 (b), the ideal sensor characteristic is that the X-axis stroke error is 0 mm. In FIG. 8 (a), neither reciprocation moves on the X-axis, but the hysteresis loop of reciprocation. Is offset and the linearity of the waveform is also poor.

  On the other hand, FIG. 8 (b) shows the sensor characteristics when the sensor characteristic is corrected by approximating the median of the characteristic after the sensor 113 is assembled so that it becomes a theoretical value, and the mechanical characteristics are corrected. Therefore, the linearity of the sensor characteristics is improved. That is, the X-axis is located approximately at the center of the reciprocating hysteresis loop, and the median value of rattling can be approximated as an ideal value. Further, FIG. 8B is approximated as a characteristic closer to an ideal characteristic in terms of linearity. That is, it is rewritten as the sensor characteristic suitable for each actuator, and the assembly error and the linearity error of the mechanical characteristic of the actuator are eliminated.

  The actuator 100 according to the present embodiment described above is attached to the outboard motor 2 of FIG. 1 as a gear shift positioning actuator for forward / reverse switching. However, since the sensor 113 having rewritable sensor characteristics is mounted, the actuator 100 After reciprocating the drive shaft 117 of the actuator 100 after mounting to the actuator and recognizing mechanical characteristics such as linearity and assembly errors that the actuator has individually, the sensor characteristics are rewritten and corrected to ideal sensor characteristics. it can.

  That is, when the actuator 100 has rattle due to gear backlash or the like, it approximates to a straight line passing through the median value by approximating the data reciprocated by the least square method (sensor characteristics including mechanical characteristics). Approximate the ideal sensor characteristic with the median value by approximating the straight line to the ideal characteristic line. As a result, the sensor characteristics stored in the storage element of the sensor 113 can be corrected by rewriting the ideal sensor characteristics by approximating the sensor characteristics to the median value of each actuator. Note that, depending on the rewriting method to the sensor, the approximation method can be performed by the minimum area method.

  As described above, according to the actuator 100 of the present embodiment, assembling errors according to the ability of human hands or assembling jigs, differences in mechanical characteristics of individual actuators (ball screw lead pitch errors, gears) The linearity error (due to backlash of the row, etc.) can be corrected as a more ideal sensor characteristic, the position accuracy of the drive shaft 117 is improved, and the variation in actuator products is reduced.

  Next, a sensor shield structure in which a conductive plate is attached so as to surround the sensor in the above-described actuator will be described with reference to FIG.

  FIG. 9 is a cross-sectional view (a) of the main part showing the sensor shield structure and a plan view (b) of the main part of the sensor as seen from the BB direction.

  As shown in FIGS. 9A and 9B, a plurality of support columns 201 are erected on the cover member 101B on the side surface side of the sensor 113 so as to surround the sensor 113 similar to that in FIG. A sensor shield structure may be imparted to the actuator 100 by fixing and attaching a metal conductive plate 202 having high conductivity to the support column 201 with a bolt 201a.

  According to the above-described sensor shield structure, since the influence of the external noise on the sensor 113 can be reduced by the shielding effect of the conductive plate 202, the output fluctuation of the sensor due to the influence of the external noise can be suppressed, and the detection accuracy of the sensor 113 is improved. The position accuracy of the drive shaft 117 of the actuator 100 is improved.

  Further, it is not necessary to take measures such as inserting noise countermeasure components in the electric circuit of the sensor or disposing the sensor far from the noise source. In addition, since the outer surface of the sensor 113 is surrounded by the plurality of support columns 201 and the conductive plate 202, the sensor 113, which is an important component in the actuator 100, can be physically protected (damage protection due to dropping or the like). .

  In addition, when the actuator 100 is installed in a place where seawater is applied depending on the use of a ship or the like, the shielding effect may be reduced because seawater adheres to the conductive plate 202 and rust is generated. With respect to the plate 202, it is preferable to apply a rust preventive coating that does not impair the conductivity or to adopt a material that is not easily rusted (stainless steel or the like).

  By adding the sensor shield structure of FIG. 9 to the actuator 100 described above, it is possible to improve both the accuracy error of the positioning actuator and the resistance to externally induced noise, and to improve the position accuracy of the positioning actuator.

  As described above, the best mode for carrying out the present invention has been described. However, the present invention is not limited to these, and various modifications are possible within the scope of the technical idea of the present invention. For example, the actuator of the present invention is preferably used as a positioning actuator used for a gear shift for forward / reverse switching of a ship, but is not limited to this and may be used for other purposes.

It is the schematic of the outboard motor using the actuator concerning this Embodiment. It is a front view of the actuator of this Embodiment. FIG. 3 is a diagram when the actuator of FIG. 2 is viewed in the direction of arrow III. It is the figure which cut | disconnected the structure of FIG. 3 by the IV-IV line and looked at the arrow direction. FIG. 5 is a diagram schematically showing a reference position (neutral position N) of a drive shaft 117 of the actuator 100 when the sensor of FIG. 4 is attached to the actuator. It is a block diagram which shows schematic structure of the sensor characteristic rewriting apparatus which rewrites the sensor characteristic of the sensor 113 of FIG. Measurement data (solid line) obtained by sampling the stroke amount (movement amount) when the drive shaft 117 of the sensor 113 is reciprocated and the sensor voltage output from the sensor 113, and the minimum based on the reciprocation measurement data. It is a figure which shows the center primary approximated straight line (broken line) calculated by the square method. Graph (a) showing sensor characteristics in relation to stroke amount and stroke error when sensor characteristics are not rewritten to sensor 113 (attached state), and stroke amount when rewriting with median value as described above It is a graph (b) which shows a sensor characteristic by the relationship between a stroke error. It is principal part sectional drawing (a) which shows a sensor shield structure, and the principal part top view (b) of the sensor seen from BB direction.

Explanation of symbols

2 Outboard motor 20 Sensor characteristic rewriting device 21 Stroke sensor 22 Motor controller 23 Measuring instrument 24 Sensor rewriting jig 25 Arithmetic device 26 Changeover switch 100 Actuator 113 Sensor 113a Measuring shaft 117 Drive shaft 201 Strut 202 Conductive plate

Claims (10)

An actuator equipped with a sensor,
An actuator characterized in that the sensor characteristics can be rewritten after the sensor is attached to the actuator.   Means for operating the actuator to measure its movement amount and sensor output to obtain output data; means for calculating ideal sensor characteristics based on the output data and sensor characteristics before rewriting; and The actuator according to claim 1, further comprising means for rewriting a characteristic to the calculated sensor characteristic.   The actuator according to claim 2, wherein the sensor characteristic is approximated and rewritten by a median value of the backlash of the actuator obtained from the output data.   The output data obtained by reciprocating the actuator is approximated by the least square method to approximate a straight line passing through the median value of the actuator, and the straight line is approximated to an ideal characteristic straight line. The actuator according to claim 2, wherein the sensor characteristic is approximated and rewritten with a median value of λ.   The actuator according to claim 1, wherein a conductive plate is attached so as to surround the sensor.   The actuator according to claim 1, wherein the sensor includes a rewritable storage element that stores the sensor characteristics.   The actuator according to any one of claims 1 to 6, wherein the actuator is used as a positioning actuator for a gear shift for forward / reverse switching of a ship. A sensor characteristic correcting method for rewriting and correcting a sensor characteristic after attaching the sensor in an actuator equipped with a sensor,
The actuator is actuated to measure its movement amount and sensor output to obtain output data, ideal sensor characteristics are calculated based on the output data and sensor characteristics before rewriting, and the sensor characteristics are calculated. A sensor characteristic correction method for an actuator, characterized in that the sensor characteristic is rewritten to a specified sensor characteristic.   9. The actuator sensor characteristic correction method according to claim 8, wherein the actuator data is measured from the output data, and the sensor characteristic is approximated and rewritten by a median value of the data.   The output data obtained by reciprocating the actuator is approximated by a least square method to approximate a straight line passing through the median value of the actuator, and the straight line is approximated to an ideal characteristic straight line. The sensor characteristic correction method for an actuator according to claim 8, wherein the sensor characteristic is rewritten by approximating a median value.

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