JP2010181330A - Encoder and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for detecting correctly a rotation direction of a rotator by using an encoder including two detection elements. <P>SOLUTION: This encoder 10 includes the detection elements 2a, 2b for output of a detection signal showing a detected magnetic field, a magnetic pole 3, and a rotation detection unit 6 for detecting which direction between a normal direction and a reverse direction is the rotation direction of the rotator. The magnetic pole 3 includes a plurality of N-pole domains 4 and a plurality of S-pole domains 5. The plurality of N-pole domains 4 and the plurality of S-pole domains 5 are alternately arranged along the rotation direction of the rotator. The width of the N-pole domain 4 (length along the rotation direction of the rotator) is wider than the width of the S-pole domain 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an encoder and a vehicle, and more particularly to a technique for detecting the rotation direction of a rotating body using a magnetic encoder.

  An encoder is known as a device that detects the rotation of a rotating body. Some encoders are magnetic.

  For example, Japanese Patent Laying-Open No. 2006-30091 (Patent Document 1) discloses a magnetic encoder that can determine the rotation direction of normal rotation or reverse rotation without increasing the number of parts. This magnetic encoder has a track that rotates relative to a detection means for detecting a magnetic field. The magnetization pattern of the track is a pattern in which a narrow pitch between a pair of magnetic poles and a wide pitch between a pair of magnetic poles are continuous. A magnetized pattern is repeatedly formed on the track at least twice.

JP 2006-30091 A JP 2007-24887 A JP 2007-71709 A

  In the magnetic encoder disclosed in Japanese Patent Laying-Open No. 2006-30091 (Patent Document 1), the magnetic field of a track is detected by one magnetic sensor. On the other hand, a magnetic encoder that employs a system that detects the magnetic field of a track with two magnetic sensors is also known. However, Japanese Patent Laying-Open No. 2006-30091 does not disclose a configuration in which the magnetism of a track having the above-described magnetization pattern is detected by two sensors.

  The objective of this invention is providing the technique for detecting correctly the rotation direction of a rotary body using the encoder provided with two detection elements.

  In summary, the present invention is an encoder, which is arranged along the rotation direction of a rotating body capable of rotating a shaft, and outputs first and second detection elements each outputting a detection signal indicating a detected magnetic field; And a magnetic pole portion provided on the rotating body along the rotating direction of the rotating body so as to face the second detecting element, and based on detection signals from each of the first and second detecting elements, A rotation detection unit that detects whether the rotation direction is a first direction or a second direction opposite to the first direction. The magnetic pole portions are alternately arranged with a plurality of first regions magnetized by the first magnetic poles and a plurality of first regions, and a plurality of first regions magnetized by the second magnetic poles. 2 regions. Each of the plurality of first regions has a first width along the rotation direction of the rotating body. Each of the plurality of second regions has a second width along the rotation direction of the rotating body. The first width is greater than the second width.

  Preferably, each of the first and second widths is larger than an interval between the first and second detection elements along the rotation direction of the rotating body.

  Preferably, the rotation detection unit generates a differential signal of each detection signal of the first and second detection elements, and the voltage level is based on the first and second voltage levels based on the differential signal. A pulse generation unit that outputs a pulse signal that switches between levels. The pulse generation unit sets the voltage level of the pulse signal to the first and second levels when the intensity of the differential signal exceeds a predetermined upper limit value and when the intensity of the differential signal falls below a predetermined lower limit value. Switch between.

  Preferably, the pulse generator changes the voltage level of the pulse signal from the first level to the second level when the intensity of the differential signal exceeds a predetermined upper limit value, while the intensity of the differential signal When the voltage falls below a predetermined lower limit, the voltage level of the pulse signal is changed from the second level to the first level.

  When the other situation of this invention is followed, it is a vehicle, Comprising: The encoder in any one of the above-mentioned is provided.

  Preferably, the vehicle further includes an automatic transmission having an input rotating member and an output rotating member, a rotating electrical machine, an engine, wheels, and a differential device. The differential has a first rotating element connected to the rotating electrical machine, a second rotating element connected to the input rotating member of the automatic transmission, and a third rotating element connected to the engine. The differential device is configured such that the rotation speed of the first rotation element is determined according to the rotation speeds of the second and third rotation elements. The encoder detects the rotation direction of the output rotation member of the automatic transmission as the rotation direction of the rotating body.

  According to the present invention, the rotation direction of an object can be correctly detected by an encoder including two detection elements.

1 is a schematic configuration diagram of an encoder according to an embodiment of the present invention. FIG. 4 is a diagram for explaining a magnetization pattern of a magnetic pole part 3; 4 is a block diagram illustrating a configuration of a rotation detection unit 6. FIG. It is a figure explaining the example of the magnetization pattern of a magnetic pole part for detecting the rotation direction of a rotary body with a 1 element type encoder. It is a wave form diagram which shows the signal output from a magnetic sensor when the magnetic pole part 3a shown in FIG. 4 is used. It is a figure explaining a 1 element type magnetic encoder and a 2 element type encoder by contrasting. FIG. 5 is a waveform diagram showing an output waveform of a detection unit when the magnetization pattern shown in FIG. 4 is applied to a one-element type magnetic encoder. FIG. 5 is a waveform diagram showing an output waveform of a detection unit when the magnetization pattern shown in FIG. 4 is applied to a two-element type magnetic encoder. It is a figure explaining the state in which the detection element of a two-element type magnetic encoder detects a magnetic pole. It is a figure which shows the phase difference of the detection signal which shows the magnetic flux density detected by the detection element 2a, and the detection signal which shows the magnetic flux density detected by the detection element 2b. It is a wave form diagram for demonstrating the detection of the rotation direction of a rotary body by this Embodiment. It is a schematic block diagram which shows the hybrid vehicle carrying the encoder which concerns on this Embodiment. It is a figure which shows a hybrid system and an automatic transmission. It is a figure which shows the alignment chart of a power split device. It is a figure which shows a hydraulic control apparatus. It is a figure explaining the possibility that the rotation speed of 1st MG311 will rise rapidly. It is a figure explaining control of the number of rotations of the 1st MG311 using the encoder by this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

(Encoder configuration)
FIG. 1 is a schematic configuration diagram of an encoder according to an embodiment of the present invention. Referring to FIG. 1, an encoder 10 includes a detection unit 2 including detection elements 2 a and 2 b for detecting magnetism, and a magnetic pole unit 3 mounted on a side surface of the plate 1 along the rotation direction of the plate 1. The rotation detection unit 6 is provided.

  The plate 1 is a rotating body that rotates about one axis. In FIG. 1, the rotation center axis of the plate 1 is indicated by a one-dot chain line.

  Each of the detection elements 2a and 2b detects a magnetic field and outputs a signal indicating the detected magnetic field. As the detection elements 2a and 2b, for example, a magnetic head using an electromagnetic induction action, a differential transformer, a hall element using an action of converting magnetic force into electricity, an MR element (magnetoresistance effect element), or the like can be employed.

  The magnetic pole part 3 is a rubber magnet, for example, and is provided on the side surface of the plate 1. The detection surfaces of the detection elements 2a and 2b are arranged to face the main surface (magnetized surface) of the magnetic pole part 3.

  The magnetic pole part 3 includes a plurality of N-pole regions 4 and a plurality of S-pole regions 5. The “N-pole region” means a region where the surfaces facing the detection surfaces of the detection elements 2a and 2b are magnetized (magnetized) to the N-pole, and the “S-pole region” means the detection elements 2a, 2b, 2b means a region in which the surface facing each detection surface is magnetized to the S pole.

  FIG. 2 is a diagram for explaining the magnetization pattern of the magnetic pole portion 3. Referring to FIGS. 2 and 1, N-pole regions 4 and S-pole regions 5 are alternately arranged along the rotation direction of plate 1. In FIG. 2, the rotation direction of the plate 1 shown in FIG.

  In this specification, the “width” of the N-pole region 4 and the S-pole region 5 is defined as the length of the plate 1 in the rotation direction. As shown in FIG. 2, the N pole regions 4 have the same width, and the S pole regions 5 have the same width. If the width of the N pole region 4 is W1 and the width of the S pole region 5 is W2, W1 is larger than W2. Note that both the width W1 of the N-pole region 4 and the width W2 of the S-pole region 5 are larger than the distance between the detection elements 2a and 2b.

  Returning to FIG. 1, the rotation detection unit 6 determines that the rotation direction of the plate 1 is the forward direction and the reverse direction with respect to the positive direction based on the signal from the detection unit 2 (the signal from each of the detection elements 2a and 2b). Detect which one. In the following description, “forward rotation” means rotation of the plate 1 in the forward direction, and “reverse rotation” means rotation of the plate 1 in the reverse direction.

  FIG. 3 is a block diagram illustrating the configuration of the rotation detection unit 6. With reference to FIG. 3, the rotation detection unit 6 includes a differential calculation unit 11 and a pulse generation unit 12. The differential calculation unit 11 generates a differential signal by calculating a difference between detection signals output from the detection elements 2a and 2b. The pulse generation unit 12 outputs a pulse signal whose voltage level changes between the H level and the L level based on the differential signal generated by the differential operation unit 11. The “H level” is a voltage level when the voltage of the pulse signal is higher than a predetermined voltage, and the “L level” is a voltage level when the voltage of the pulse signal is lower than the predetermined voltage. .

  As will be described later, the pulse generator 12 varies the period in which the rotation direction of the plate 1 is the forward direction and the reverse direction and the voltage level of the pulse signal is H level (the same applies to the period in which the voltage level is L level). Make it. Therefore, according to the present embodiment, the rotation direction of the plate 1 can be detected based on the period in which the pulse signal output from the pulse generator 12 is at the H level (or L level).

(Example of magnetization pattern in single-element encoder)
The encoder according to the present embodiment detects the rotation direction of the rotating body by the magnetic pole part and the two detection elements. On the other hand, there has also been proposed a magnetic encoder capable of detecting the rotation direction of the rotating body with only one detection element by devising the magnetization pattern of the magnetic pole portion. Hereinafter, for the sake of convenience, a magnetic encoder including one magnetic sensor is referred to as a “one element type”, and a magnetic encoder including two magnetic sensors is referred to as a “two element type”.

  FIG. 4 is a diagram for explaining an example of a magnetization pattern of the magnetic pole portion for detecting the rotation direction of the rotating body by the one-element type encoder. Referring to FIG. 4, magnetic pole portion 3a has a magnetized pattern in which wide regions A1 and narrow regions A2 are alternately arranged. Wide region A1 includes a pair of N-pole region 4a and S-pole region 5a. Narrow region A2 includes a pair of N-pole region 4b and S-pole region 5b. The width of the N pole region 4a is larger than the width of the N pole region 4b. Similarly, the width of the south pole region 5a is larger than the width of the south pole region 5b.

  FIG. 5 is a waveform diagram showing signals output from the magnetic sensor when the magnetic pole portion 3a shown in FIG. 4 is used. Referring to FIGS. 5 and 4, the H level and L level of the signal correspond to the state in which the magnetic sensor (not shown) detects the N pole and the state in which the magnetic sensor detects the S pole, respectively. However, the correspondence relationship between the H level and L level of the signal and the N and S poles may be opposite to the above relationship.

  The rotation start positions A to D indicate positions on the magnetic pole portion facing the magnetic sensor when the rotation of the rotating body is started. The rotation start position A indicates a position in the narrow N pole region (4b), the rotation start position B indicates a position in the narrow S pole region (5b), and the rotation start position C indicates a wide N pole region. The position in (4a) is shown, and the rotation start position D is a position in the narrow south pole region (5a).

  When the rotating body starts to rotate in the positive direction from the rotation start position A, the voltage level of the signal changes between the L level and the H level. That is, H level pulses and L level pulses are alternately output. The width of the L level (or H level) pulse is a width corresponding to the width of the N pole (S pole) region. The time t1 is the time when the L level pulse is output, the time t2 is the time when the H level pulse is output, the time t3 is the time when the L level pulse is output, and the time t4 is the time when the H level pulse is output It's time. As shown in FIG. 4, since the wide areas A1 and the narrow areas A2 are alternately arranged in the magnetic pole part 3a, the relationship of t1 <t3 and t2> t4 is established.

  Hereinafter, for ease of explanation, a combination of a pulse width (wide / narrow) and a pulse output level (H / L) is described as “wide (L)”.

  For example, when the rotating body starts to rotate in the positive direction from the rotation start position A, pulses are output in the order of narrow (L), wide (H), wide (L), and narrow (H). On the other hand, when the rotating body starts to rotate in the reverse direction from the rotation start position A, pulses are output in the order of wide (L), wide (H), narrow (L), and narrow (H). Accordingly, by determining whether the pulse output after the wide (H) pulse is wide (L) or narrow (L), normal rotation and reverse rotation of the rotating body can be determined.

  Even when the rotation start position is any one of B to D, as in the case of the rotation start position A, the forward rotation and reverse rotation of the rotating body are performed based on the pulse output after the wide (H) pulse. Can be determined.

  However, the magnetization pattern shown in FIG. 4 can be applied when the rotation direction of the rotating body is detected by one magnetic sensor, but when two magnetic sensors are used as in the present embodiment. May not be able to detect the rotation direction of the rotating body.

(About 1 element type and 2 element type)
FIG. 6 is a diagram illustrating a comparison between a one-element magnetic encoder and a two-element encoder.

  Referring to FIG. 6, the rotating body 1 a is a toothed plate-like rotor (FIG. 6A). The rotating body 1a is shown in FIG. 6 in order to explain the difference between the one-element type and the two-element type, and does not limit the magnetic encoder according to the present embodiment.

  As shown in FIG. 6B, in the case of the single element type, the convex portion and the concave portion (mountain and valley) of the rotating body 1a are detected by one magnetic sensor provided in the detection unit 2. For this reason, at the time of rotation of the rotating body 1a, it is necessary that the fluctuation of the gap between the detection unit 2 and the rotating body 1a is small. However, the gap between the detection unit 2 and the rotating body 1a may fluctuate greatly during the rotation of the rotating body 1a due to the eccentricity of the rotating body 1a.

  When a toothed plate-like rotating body is used, the magnetic flux density detected by the detecting unit 2 (magnetic sensor) changes depending on the distance between the detecting unit 2 and the rotating body 1a. For example, it is assumed that the distance between the detection unit 2 and the valley of the rotating body 1a is d at a certain rotational position of the rotating body 1a. Further, it is assumed that the distance between the detection unit 2 and the mountain of the rotating body 1a is d at another rotational position. In these cases, since the magnitudes of the detected magnetic flux densities are the same, there is a possibility that the rotation (rotation direction or number of rotations) of the rotating body cannot be accurately detected.

  On the other hand, in the case of the two-element type, the boundary between the crest and trough of the rotating body is detected based on the difference (differential signal) between the outputs of the two detection elements. As shown in FIG. 6C, when the two detection elements face the crest and trough portions of the rotating body, the intensity of the differential signal increases. This relationship is established regardless of the distance between the detection unit 2 and the rotating body. Therefore, even when the gap between the detection unit 2 and the rotating body 1a is likely to fluctuate during the rotation of the rotating body 1a, the possibility of erroneously detecting the rotation (rotating direction or number of rotations) of the rotating body can be reduced. .

  From the above description, it can be said that the two-element magnetic encoder is more versatile than the one-element magnetic encoder. However, when the magnetic pole portion 3a shown in FIG. 4 is applied to a two-element magnetic encoder, there is a possibility that the rotation direction cannot be detected.

(Problem when applying 1 element type magnetizing pattern to 2 element type)
FIG. 7 is a waveform diagram showing an output waveform of the detection unit when the magnetization pattern shown in FIG. 4 is applied to a one-element type magnetic encoder.

  Referring to FIG. 7, when the rotating body rotates, the magnetic flux density changes according to the magnetic pole in the region facing the detection element. When the rotational speed of the rotating body is constant, the period of the waveform WV0 indicating the change in magnetic flux density depends on the width of the N-pole region (and S-pole region). While the pair of wide regions (the wide region A1 in FIG. 4) faces the detection element, the period of the waveform WV0 becomes long. On the other hand, the period of the waveform WV0 is shortened while the pair of narrow regions (the narrow region A2 in FIG. 4) faces the detection element.

  As shown in FIG. 7, the voltage level of the pulse signal output from the detection unit is such that the value of the magnetic flux density is larger than the positive threshold value Th1, and the value of the magnetic flux density is a negative threshold value. It will change when it becomes smaller than Th2. When the rotating body is rotating forward, pulses are output in the order of wide (H), narrow (L), narrow (H), and wide (L) from the detection unit. ), Wide (L), narrow (H), narrow (L) in this order.

  FIG. 8 is a waveform diagram showing an output waveform of the detection unit when the magnetization pattern shown in FIG. 4 is applied to a two-element type magnetic encoder.

  Referring to FIG. 8, waveform WV1 indicating the magnetic flux density has a flat portion. In the flat part, the value of the magnetic flux density is between the threshold value Th1 and the threshold value Th2. Further, in the flat portion, the change in the magnetic flux density with respect to the rotation angle of the rotating body is gentler than the change in the other part of the waveform WV1.

  This flat part causes the width of the pulse output from the detection part to become longer (or shorter) than the original width. For example, as shown in FIG. 8, pulses are output in the order of wide (H), narrow (L), narrow (H), and wide (L) when the rotating body is reversed. Originally, pulses must be output in the order of wide (H), wide (L), narrow (H), and narrow (L) when the rotating body reverses. That is, the flat portion changes the second output pulse from a wide (L) pulse to a narrow (L) pulse and the fourth output pulse from a narrow (L) pulse to a wide (L ).

  On the other hand, during normal rotation of the rotating body, pulses are output in the order of wide (H), narrow (L), narrow (H), and wide (L). That is, the same pulse is output when the rotating body rotates forward and backward. Therefore, when a flat part arises in the waveform of magnetic flux density, the problem that the rotation direction of a rotary body cannot be distinguished arises.

Next, the reason why the flat portion is generated in the waveform indicating the magnetic flux density will be described.
FIG. 9 is a diagram for explaining a state in which the detection element of the two-element type magnetic encoder detects the magnetic pole. Referring to FIG. 9, detection elements 2a and 2b are arranged at a predetermined distance L (for example, several mm) in the rotation direction. When the magnetic pole part 3a moves with the rotation of the rotating body, the magnetic flux density detected by each of the detection elements 2a and 2b changes. However, the detection elements 2a and 2b are arranged apart from each other. Therefore, as shown in FIG. 10, a phase difference φ is generated between the detection signal SA indicating the magnetic flux density detected by the detection element 2a and the detection signal SB indicating the magnetic flux density detected by the detection element 2b. Due to this phase difference φ, a flat portion is generated in a waveform (corresponding to the magnetic flux density waveform shown in FIG. 8) indicating the result of the difference calculation of the detection signals SA and SB.

(Detection of rotation direction according to this embodiment)
FIG. 11 is a waveform diagram for explaining the detection of the rotational direction of the rotating body according to the present embodiment. Referring to FIG. 11, “forward rotation” and “reverse rotation” in the drawing mean rotation of the rotating body. However, in FIG. 11, the arrows indicating “forward rotation direction” and “reverse rotation direction” indicate the relative movement direction of the detection unit 2 with respect to the magnetic pole unit 3. As shown in FIG. 11, there is a phase difference between the output signal of the detection element 2a and the output signal of the detection element 2b. This is because the detection elements 2a and 2b are arranged apart from each other as described above.

  Referring to FIGS. 11 and 3, in the present embodiment, differential operation unit 11 calculates the difference between the output signal of detection element 2a and the output signal of detection element 2b. As a result, the differential signal shown in FIG. The pulse generator 12 compares the intensity of the differential signal with the threshold value Th1 and the threshold value Th2.

  The pulse generator changes the voltage level of the pulse signal from the L level to the H level when the intensity of the differential signal exceeds the threshold value Th1. On the other hand, the pulse generator 12 changes the voltage level of the pulse signal from the H level to the L level when the intensity of the differential signal falls below the threshold Th2.

  The detection elements 2a and 2b are provided at a certain distance. Thereby, a phase difference is generated between the signals output from the detection elements 2a and 2b. Due to this phase difference, the intensity of the differential signal changes around the reference value. The reference value of the intensity of the differential signal is the intensity of the differential signal when both the detection elements 2a and 2b face the N-pole region 4 (or S-pole region 5), and is 0, for example.

  The threshold value Th1 is larger than the reference value and smaller than the maximum value Max of the differential signal intensity. Thereby, the timing when the intensity | strength of a differential signal exceeds threshold value Th1 can be varied by the time of forward rotation of a rotary body, and the time of reverse rotation. That is, the timing at which the voltage level of the pulse signal changes from the L level to the H level can be made different between the normal rotation and the reverse rotation of the rotating body.

  Similarly, the threshold value Th2 is smaller than the reference value and larger than the minimum value Min of the differential signal intensity. Thereby, the timing when the intensity | strength of a differential signal is less than threshold value Th2 can be varied by the time of forward rotation of a rotary body, and the time of reverse rotation. That is, the timing at which the voltage level of the pulse signal changes from the H level to the L level can be made different between the normal rotation and the reverse rotation of the rotating body.

  Thus, the voltage level of the pulse signal when the detection elements 2a and 2b are opposed to the N pole region 4 by changing the timing of changing the voltage level of the pulse signal between the normal rotation and the reverse rotation of the rotating body. Can be made different between the forward rotation and the reverse rotation of the rotating body. That is, when the rotating body rotates in the forward direction, the voltage level of the pulse signal when the detection elements 2a and 2b face the N-pole region 4 is L level. On the other hand, when the rotating body reverses, the voltage level of the pulse signal when the detection elements 2a and 2b face the N-pole region 4 becomes the H level. Note that the voltage level of the pulse signal when the detection elements 2a and 2b face the south pole region 5 is also different between when the rotating body is rotating forward and when it is rotating backward.

Furthermore, according to the present embodiment, the width of the N-pole region 4 is made larger than the width of the S-pole region 5.
As a result, the period during which the pulse signal is at the H level (or L level) can be made different between the forward rotation and the reverse rotation of the rotating body.

  That is, according to the present embodiment, the encoder 10 detects the rotation direction of the rotating body and outputs a signal corresponding to the detection result. The signal output from the encoder 10 differs between when the rotating body is rotating forward and when it is rotating backward. That is, according to the present embodiment, the encoder can correctly detect the rotation direction of the rotating body.

  Note that the encoder according to the present embodiment may be configured to detect not only the rotation direction of the rotating body but also the rotation speed. For example, a magnetic pattern indicating a reference point (for example, 0 °) of the rotational position of the rotating body is formed on the magnetic pole portion 3, and the detection elements 2a and 2b output a pulse signal corresponding to the magnetic pattern at a predetermined time (for example, 1 second). By counting the number of times of rotation, the number of rotations of the rotating body can be detected.

(Application example of encoder according to this embodiment)
With reference to FIG. 12, a hybrid vehicle equipped with an encoder according to an embodiment of the present invention will be described. This hybrid vehicle is an FR (Front engine Rear drive) vehicle, but may be a vehicle other than FR.

  The hybrid vehicle includes a hybrid system 100 as a drive source, an automatic transmission 400, a propeller shaft 500, a differential gear 600, a rear wheel 700, and an ECU (Electronic Control Unit) 800. The control device according to the present embodiment is realized, for example, by executing a program recorded in ROM (Read Only Memory) 802 of ECU 800. ECU 800 may be divided into a plurality of ECUs.

  The hybrid vehicle power train includes a hybrid system 100 and an automatic transmission 400. The engine 200 of the hybrid system 100 is an internal combustion engine that burns a mixture of fuel and air injected from an injector 202 in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Automatic transmission 400 is coupled to the output shaft of hybrid system 100. The driving force output from the automatic transmission 400 is transmitted to the left and right rear wheels 700 via the propeller shaft 500 and the differential gear 600.

  The ECU 800 includes a position switch 806 for the shift lever 804, an accelerator opening sensor 810 for the accelerator pedal 808, a stroke sensor 814 for the brake pedal 812, a throttle opening sensor 818 for the electronic throttle valve 816, and an engine speed sensor 820. The input shaft rotational speed sensor 822, the encoder 10, the oil temperature sensor 826, and the water temperature sensor 828 are connected via a harness or the like.

  The position (position) of shift lever 804 is detected by position switch 806, and a signal representing the detection result is transmitted to ECU 800. Corresponding to the position of the shift lever 804, a shift in the automatic transmission 400 is automatically performed.

  Accelerator opening sensor 810 detects the opening of accelerator pedal 808 and transmits a signal representing the detection result to ECU 800. The stroke sensor 814 detects the operation amount of the brake pedal 812 (the amount by which the driver steps on the brake pedal 812), and transmits a signal representing the detection result to the ECU 800.

  The throttle opening sensor 818 detects the opening of the electronic throttle valve 816 whose opening is adjusted by the actuator, and transmits a signal indicating the detection result to the ECU 800. The electronic throttle valve 816 adjusts the amount of air taken into the engine 200 (output of the engine 200).

  Instead of or in addition to the electronic throttle valve 816, the amount of air sucked into the engine 200 is changed by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  Engine rotation speed sensor 820 detects the rotation speed (engine rotation speed NE) of the output shaft (crankshaft) of engine 200 and transmits a signal representing the detection result to ECU 800. Input shaft speed sensor 822 detects input shaft speed NI of automatic transmission 400 and transmits a signal representing the detection result to ECU 800.

  Encoder 10 according to the present embodiment is an output shaft rotational speed sensor that detects the rotational direction and rotational speed NO of the output shaft of automatic transmission 400. The encoder 10 transmits a signal representing the detection result to the ECU 800.

  The vehicle speed of the hybrid vehicle is calculated from the output shaft rotational speed NO of automatic transmission 400. In addition, about the method of calculating a vehicle speed, since what is necessary is just to use a known general technique, the detailed description is not repeated here.

  Oil temperature sensor 826 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 400 and transmits a signal representing the detection result to ECU 800.

  Water temperature sensor 828 detects the temperature (water temperature) of cooling water for engine 200 and transmits a signal representing the detection result to ECU 800.

  The ECU 800 includes a position switch 806, an accelerator opening sensor 810, a stroke sensor 814, a throttle opening sensor 818, an engine speed sensor 820, an input shaft speed sensor 822, an encoder 10 (output shaft speed sensor), and an oil temperature sensor 826. Based on the signal sent from the water temperature sensor 828 and the like, the map stored in the ROM 802, and the program, the devices are controlled so that the vehicle is in a desired running state.

  The hybrid system 100 and the automatic transmission 400 will be further described with reference to FIG.

  Hybrid system 100 includes an engine 200, a power split mechanism 310, a first MG (Motor Generator) 311, and a second MG 312. Power split device 310 splits the output of engine 200 input to input shaft 302 into first MG 311 and output shaft 304. Power split device 310 includes planetary gear 320.

  Planetary gear 320 includes a sun gear 322, a pinion gear 324, a carrier 326 that supports the pinion gear 324 so as to rotate and revolve, and a ring gear 328 that meshes with the sun gear 322 via the pinion gear 324.

  In power split device 310, carrier 326 is connected to input shaft 302, that is, engine 200. Sun gear 322 is connected to first MG 311. Ring gear 328 is coupled to output shaft 304. Torque of ring gear 328 is transmitted to rear wheel 700.

  Power split device 310 functions as a differential device by relatively rotating sun gear 322, carrier 326, and ring gear 328. Due to the differential function of power split device 310, the output of engine 200 is distributed to first MG 311 and output shaft 304.

  The first MG 311 generates electric power using a part of the output of the distributed engine 200, or the second MG 312 is rotationally driven using electric power generated by the first MG 311 so that the power split mechanism 310 is a continuously variable transmission. Function as.

  First MG 311 and second MG 312 are three-phase AC rotating electric machines. First MG 311 is coupled to sun gear 322 of power split device 310. Second MG 312 is provided such that the rotor rotates integrally with output shaft 304.

  First MG 311 and second MG 312 are controlled so as to satisfy the target output torque of automatic transmission 400 calculated from, for example, the accelerator opening and the vehicle speed, and to realize optimum fuel consumption in engine 200.

  The rotational speed of the first MG 311, the rotational speed of the second MG 312, and the engine rotational speed NE are in a relationship of being connected by a straight line in the nomograph as shown in FIG. 14. That is, the remaining one rotation speed is forcibly determined based on any two rotation speeds among the rotation speed of the first MG 311, the rotation speed of the second MG 312, and the engine rotation speed NE. Therefore, as indicated by a broken line in FIG. 14, if the engine speed NE does not decrease when the rotation speed of the second MG 312 decreases, the rotation speed of the first MG 311 increases. In the present embodiment, “decrease in the rotational speed of second MG 312” includes a case where the rotational speed changes from a positive rotational speed (when the vehicle moves forward) to a negative rotational speed (when the vehicle moves backward).

  Returning to FIG. 13, the automatic transmission 400 includes an input shaft 404 as an input rotating member disposed on a common axis in a case 402 as a non-rotating member attached to the vehicle body, and an output as an output rotating member. Axis 406.

  Input shaft 404 is connected to output shaft 304 of power split device 310. Therefore, the input shaft rotational speed NI of automatic transmission 400 and the output shaft rotational speed of power split device 310, that is, rotational speed NR of ring gear 328 are the same.

  The automatic transmission 400 includes a single pinion type first planetary gear (P1) 410 and a second planetary gear (P2) 420, and five frictional engagements including a C1 clutch 431, a C2 clutch 432, a C3 clutch 433, a B1 brake 441, and a B2 brake 442. And a combination element.

  Automatic transmission 400 further includes a one-way clutch (F) 450. The one-way clutch (F) 450 allows relative rotation of the inner race 452 and the outer race 454 in one direction and restricts the reverse direction. In the present embodiment, the engaged state of the one-way clutch (F) 450 means a state where relative rotation between the inner race 452 and the outer race 454 is restricted.

  First planetary gear (P1) 410 includes a sun gear (S1) 412, a carrier (CA1) 414, and a ring gear (R1) 416. The sun gear (S1) 412 is connected to the input shaft 404 by the engagement of the C3 clutch 433. The sun gear (S1) 412 is fixed to the case 402 by the engagement of the B1 brake 441.

  The carrier (CA1) 414 is connected to the input shaft 404 by engagement of the C2 clutch 432. The carrier (CA1) 414 is fixed to the case 402 by the engagement of the B2 brake 442 or the one-way clutch (F) 450. Ring gear (R 1) 416 is coupled to output shaft 406.

  Second planetary gear (P2) 420 includes a sun gear (S2) 422, a carrier (CA2) 424, and a ring gear (R2) 426. The sun gear (S2) 422 is connected to the input shaft 404 by engagement of the C1 clutch 431.

  The carrier (CA2) 424 is coupled to the output shaft 406. Ring gear (R2) 426 is coupled to carrier (CA1) 414 of first planetary gear (P1) 410. Therefore, the ring gear (R2) 426 is fixed to the case 402 by the engagement of the B2 brake 442 or the one-way clutch (F) 450.

  A desired gear stage is formed in the automatic transmission 400 by engaging the friction engagement elements of the automatic transmission 400 in a predetermined combination.

  In a state where the gear stage is formed in automatic transmission 400, torque (output torque of hybrid system 100) input from ring gear 328 of power split mechanism 310 to automatic transmission 400 is transmitted to rear wheel 700 that is a drive wheel.

  In the neutral state of automatic transmission 400, all the frictional engagement elements are released. In the neutral state, transmission of torque from the ring gear 328 of the power split mechanism 310 to the rear wheel 700 is interrupted.

  The C1 clutch 431, the C2 clutch 432, the C3 clutch 433, the B1 brake 441 and the B2 brake 442 are operated by hydraulic pressure. In the present embodiment, as shown in FIG. 15, the hybrid vehicle is provided with a hydraulic control device 900 that supplies / discharges hydraulic pressure to / from each friction engagement element and controls engagement / release.

  The hydraulic control apparatus 900 adjusts the hydraulic pressure generated by the mechanical oil pump 910, the electric oil pump 920, and the oil pumps 910 and 920 to the line pressure, and the hydraulic pressure adjusted using the line pressure as the original pressure. And a hydraulic circuit 930 that supplies oil for lubrication to an appropriate location.

  Mechanical oil pump 910 is a pump that is driven by engine 200 to generate hydraulic pressure. The mechanical oil pump 910 is disposed coaxially with the carrier 326 and is operated by receiving torque from the engine 200. That is, when the carrier 326 rotates, the mechanical oil pump 910 is driven, and hydraulic pressure is generated.

  On the other hand, the electric oil pump 920 is a pump driven by a motor (not shown). The electric oil pump 920 is attached to an appropriate location such as the outside of the case 402. Electric oil pump 920 is controlled by ECU 800 to generate a desired oil pressure. For example, the rotational speed of the electric oil pump 920 is feedback-controlled.

  The rotational speed of electric oil pump 920 is detected by rotational speed sensor 830, and a signal representing the detection result is transmitted to ECU 800. Further, the discharge pressure from the electric oil pump 920 is detected by the hydraulic sensor 832, and a signal indicating the detection result is transmitted to the ECU 800. The electric oil pump 920 is operated by electric power supplied from the battery 942 via the DC / DC converter 940.

  The hydraulic circuit 930 includes a plurality of solenoid valves, switching valves, or pressure regulating valves (each not shown), and is configured to be able to electrically control pressure regulation and hydraulic supply / discharge. The control is performed by the ECU 800.

  In addition, check valves 912 and 922 that open at the discharge pressure of the oil pumps 910 and 920 and close in the opposite direction are provided on the discharge side of the oil pumps 910 and 920, and the hydraulic circuit 930 includes On the other hand, these oil pumps 910 and 920 are connected in parallel to each other. In addition, a valve (not shown) that regulates the line pressure increases the discharge amount to increase the line pressure, and conversely controls the line pressure to reduce the discharge amount to lower the line pressure. Is configured to do.

  The following problems may occur in the vehicle having the above configuration. For example, assume that the position of shift lever 804 is selected as the drive (D) position or the reverse (R) position while the vehicle is running with automatic transmission 400 in the neutral state.

  Various methods for determining the traveling direction of the vehicle at this time are conceivable. For example, the second MG 312 can be operated with the clutch (at least one of the C1 clutch to the C3 clutch) of the automatic transmission 400 engaged. A method of judging from the rotational speed can be adopted. In the present embodiment, when the position of shift lever 804 is the D position and the gear stage is the first speed gear stage, C1 clutch 431 and C3 clutch 433 are engaged. When the shift lever 804 is in the R position, the B2 brake 442 and the C3 clutch 433 are engaged.

  Next, a case will be described in which the position of the shift lever 804 is the neutral (N) position, and the position of the shift lever 804 is changed from the N position to the D position when the vehicle moves uphill. In this case, the rotation speed of the first MG 311 may increase rapidly.

  FIG. 16 is a diagram for explaining a possibility that the rotation speed of the first MG 311 rapidly increases. Referring to FIG. 16, when D position (first gear) is selected, automatic transmission 400 is connected to hybrid system 100 by C1 clutch 431. Since the vehicle is climbing up and down the hill, the direction of the vehicle is the reverse direction. Therefore, the rotational speed of output shaft 406 (shown as “Out” in FIG. 16) of automatic transmission 400 is a negative rotational speed. In this case, since the rotational speed of the second MG 312 is a negative rotational speed, it can be detected that the vehicle direction is the reverse direction based on the rotational speed of the second MG 312.

  As shown in FIG. 14, the rotational speed of first MG 311, the rotational speed of second MG 312, and engine rotational speed NE are in a relationship connected by a straight line in the nomograph. For this reason, as the absolute value of the rotation speed of the second MG 312 (absolute value of the negative rotation speed) increases, the rotation speed (positive rotation speed) of the first MG 311 increases. As a result, when the rotation speed of the first MG 311 exceeds a predetermined upper limit value UL, the first MG 311 may over-rotate. In this case, the influence on the durability of the hybrid system 100 is increased.

  The encoder according to the present embodiment can accurately detect the rotation direction. Furthermore, the encoder according to the present embodiment can detect the rotational speed. By using the encoder according to the present embodiment for the output shaft rotational speed sensor, ECU 800 can execute the following control.

  FIG. 17 is a diagram for explaining the control of the rotational speed of the first MG 311 using the encoder according to the present embodiment. Referring to FIGS. 17 and 12, when output shaft 406 rotates in the negative direction, encoder 10 outputs a signal indicating the rotation direction (negative direction) and rotation speed of output shaft 406 to ECU 800. Based on this signal, ECU 800 detects that the traveling direction of the vehicle is the backward direction. ECU 800 then waits to engage C1 clutch 431 until the rotational speed of output shaft 406 detected by encoder 10 reaches a predetermined rotational speed.

  As the absolute value of the rotational speed of the output shaft 406 decreases, the rotational speed of the output shaft 406 reaches a rotational speed that is predetermined as a rotational speed at which the first MG 311 does not over-rotate. The ECU 800 engages the C1 clutch 431 when the rotation speed of the output shaft 406 reaches the rotation speed described above. Thereby, the C1 clutch 431 can be engaged in a state where the first MG 311 does not over-rotate. Therefore, according to the present embodiment, it is possible to avoid the influence on the durability of the hybrid system 100 due to the excessive rotation of the first MG 311.

  The application of the encoder according to the present embodiment is not particularly limited. For example, the encoder according to the present embodiment includes a sensor for detecting the rotational speed of the input shaft of the automatic transmission, an engine rotational speed sensor, a sensor for detecting the rotational speed of the first MG rotational shaft, and the rotational speed of the second MG rotational shaft. The present invention can also be applied to a sensor to detect. Further, the encoder according to the present embodiment is not limited to be mounted on an automobile, and can be applied to various fields and products in which the encoder is used.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 plate, 1a rotator, 2 detector, 2a, 2b detector, 3, 3a magnetic pole, 4, 4a, 4b N pole region, 5, 5a, 5b S pole region, 6 rotation detector, 10 encoder, 11 Differential operation unit, 12 pulse generation unit, 100 hybrid system, 200 engine, 202 injector, 302 input shaft, 304 output shaft, 310 power split mechanism, 311 1st MG, 312 2nd MG, 320 planetary gear, 322 sun gear, 324 pinion gear, 326 carrier, 328 ring gear, 400 automatic transmission, 402 case, 404 input shaft, 406 output shaft, 431 C1 clutch, 432 C2 clutch, 433 C3 clutch, 441 B1 brake, 442 B2 brake, 452 Inner race 454 outer race, 500 propeller shaft, 600 differential gear, 700 rear wheel, 804 shift lever, 806 position switch, 808 accelerator pedal, 810 accelerator opening sensor, 812 brake pedal, 814 stroke sensor, 816 electronic throttle valve, 818 throttle open Degree sensor, 820 Engine speed sensor, 822 Input shaft speed sensor, 826 Oil temperature sensor, 828 Water temperature sensor, 830 Speed sensor, 832 Hydraulic sensor, 900 Hydraulic controller, 910 Mechanical oil pump, 912, 922 Check Valve, 920 electric oil pump, 930 hydraulic circuit, 940 DC / DC converter, 942 battery, A, B, C, D rotation start position, A1 wide area, A2 narrow area, L interval, V0, WV1 waveform.

Claims (6)

First and second detection elements arranged along the rotation direction of a rotating body capable of rotating the shaft and outputting detection signals indicating the detected magnetic field;
A magnetic pole portion provided on the rotating body along the rotation direction of the rotating body so as to face the first and second detection elements;
Based on the detection signal from each of the first and second detection elements, the rotation direction of the rotating body is either the first direction or a second direction opposite to the first direction. A rotation detection unit that detects
The magnetic pole part is
A plurality of first regions each magnetized by the first magnetic pole;
A plurality of second regions alternately arranged with the plurality of first regions and each magnetized by the second magnetic pole,
Each of the plurality of first regions has a first width along the rotation direction of the rotating body,
Each of the plurality of second regions has a second width along the rotation direction of the rotating body,
The encoder, wherein the first width is larger than the second width.   2. The encoder according to claim 1, wherein each of the first and second widths is larger than an interval between the first and second detection elements along the rotation direction of the rotating body. The rotation detector
A differential operation unit that generates a differential signal of the detection signal of each of the first and second detection elements;
A pulse generation unit that outputs a pulse signal whose voltage level is switched between the first and second levels based on the differential signal;
The pulse generation unit sets the voltage level of the pulse signal when the intensity of the differential signal exceeds a predetermined upper limit and when the intensity of the differential signal falls below a predetermined lower limit. The encoder according to claim 1 or 2, wherein the encoder switches between the first and second levels.   The pulse generation unit changes the voltage level of the pulse signal from the first level to the second level when the intensity of the differential signal exceeds the predetermined upper limit value. The encoder according to claim 3, wherein the voltage level of the pulse signal is changed from the second level to the first level when the intensity of the differential signal falls below the predetermined lower limit value.   A vehicle comprising the encoder according to any one of claims 1 to 4. The vehicle is
An automatic transmission having an input rotating member and an output rotating member;
Rotating electrical machinery,
Engine,
Wheels,
A first rotating element coupled to the rotating electrical machine; a second rotating element coupled to the input rotating member of the automatic transmission; and a third rotating element coupled to the engine. A differential device configured to determine the rotation speed of the first rotation element according to the rotation speed of the second and third rotation elements;
The vehicle according to claim 5, wherein the encoder detects a rotation direction of the output rotation member of the automatic transmission as the rotation direction of the rotating body.

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