KR940007921B1 - Electric Motor Actuator with Speed Sensor - Google Patents

Abstract

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Description

Electric Motor Actuator with Speed Sensor

1 to 6 are views for explaining a schematic principle of the present invention, the first diagram is a cross-sectional view along the line I-I during the fourth.

2 is a cross-sectional view showing a part of an idle speed control valve in an automobile.

3 is a diagram showing the configuration of an electric motor actuator.

4 is a partially enlarged view of the actuator showing the arrangement of the speed sensor in the actuator shown in FIG.

5 is a block diagram showing the configuration of a Hall IC.

Fig. 6 is a diagram showing the output of the Hall element and the output of the Hall IC itself in the Hall IC.

7 to 12 show the configuration of the first embodiment of the present invention, and FIG. 7 shows the aqueous phase of the speed sensor.

8 is a cross-sectional view taken along the line VII-VII during middle 7.

9 is a cross-sectional view taken along the line VII-VII during middle 7.

FIG. 10 is a diagram showing an output from each hall IC in the rotational speed sensor of FIG.

11 and 12 show the outputs from the respective Hall ICs of FIG. 10, respectively.

13 is a view showing a conventional speed sensor.

FIG. 14 is a diagram showing outputs of the Hall element of the Hall IC and the Hall IC itself in the speed sensor of FIG.

* Explanation of symbols for main parts of the drawings

26: idle speed control valve 28: valve body

42: outlet port 44: valve seat

45: valve shaft 50: neck

52: feed screw 54: wheel

72: shock gear 74: electric motor

80: rotating shaft portion (rotating body) 82a, 82b: first, second ring magnet

84a, 84b: First and second Hall ICs (magnetic probes)

The present invention relates to an electric motor-type actuator having a rotation speed sensor for detecting the rotation speed of a rotating body.

This type of rotation speed sensor is used for counting the rotation speed of an electric motor which is continuously driven, for example. Specifically, as shown in FIG. 13, the rotational speed sensor is disposed near one outer side of the rotational axis A and one magnet B fixed to the outer peripheral surface of the rotational axis A rotated by the electric motor. It consists of a magnetic probe (C). The magnetic probe C is, for example, a Hall IC including a Hall element, and is positioned so that the magnet B passes directly under the rotation axis A as the rotation axis A rotates.

From the Hall element of the magnetic probe C, every time the magnet B passes. The magnetism of this magnet B is detected, and as shown in FIG. 14, an analog voltage signal D is outputted, and this voltage signal D is a digital probe within the magnetic probe C. It is converted into a pulse signal. Therefore, from the magnetic probe C, the pulse signal E corresponding to the number of passes of the magnet B is output. In Fig. 14, two lines parallel to the horizontal axis indicate the H slice level and the L slice level, which respectively define the rising and falling points of the pulse signal E. Figs.

Therefore, by counting the pulse signal E from the magnetic process C, it is possible to obtain the rotational axis A, that is, the rotation speed of the electric motor.

By the way, the rotation speed sensor described above outputs a pulse signal E corresponding to the rotation speed of the rotation shaft A when the rotation shaft A is rotating at a predetermined speed. When the magnetic probe C and the magnet B are in the positional relationship shown in Fig. 13 after the motor is rotated inertia, and then the rotating shaft A is actually stopped, the rotating shaft is rotated. If vibration is applied to (A) or if there is looseness in the mounting of the rotating shaft A, the voltage signal is continuously displayed from the Hall element of the magnetic probe C as indicated by (Dc) in FIG. As a result, the pulse signal from the magnetic probe C is also continuously output as indicated by (Ec). As a result, a so-called chattering phenomenon occurs in the output signal of the rotation speed sensor, and it becomes impossible to accurately detect the rotation speed of the rotation shaft A. FIG.

The inconvenience described above is that since there is only one magnet B fixed to the rotation axis A, when viewed from the rotation angle of the rotation axis A in the waveform of the voltage signal D shown in FIG. The hysteresis angle θ1 (about 5 °) defined between the slice level and the L slice level is small, and therefore, the rotation axis A, that is, the magnet B, exceeds the hysteresis angle θ1. It is generated by vibration.

In order to prevent the error count of the rotational speed resulting from the above-mentioned chattering phenomenon, as shown in FIG. 14, the pulse signal Ec which is so short that there cannot be a pulse interval t1 can be ignored. That is, when viewed from the rotation angle of the rotation shaft A, for example, the area of the magnet B is set to 20 °, the area other than the magnet B is set to 340 °, and the magnetic probe is rotated from the rotational speed of the electric motor. When the period (C) detects the magnetism of the magnet B, i.e., H (or L) is 7 ms even if the period of the level is the shortest, the pulse signal (the period t1 of the H (or L) level is 7 ms or less) The filter is applied to the pulse signal Ec so as to ignore Ec). Here, in order to continue the period t1, the period t2 of the H level must be actually detected. However, as mentioned above, since the area of the magnet B seen from the rotation angle of the rotation axis A is only 20 degrees, the period t2 of the H (or L) level is very short. Therefore, it is difficult to detect the period t2 of the H (or L) level, and it is difficult to apply the above-described filter to the pulse signal Ec.

Also, even when the filter as described above is applied to the pulse signal Ec, the positional relationship between the magnet B and the magnetic probe C is in the state shown in FIG. At this time, when the rotating shaft A vibrates slowly, the filter does not function effectively, and eventually, the chattering of the pulse signal cannot be prevented, and the rotation speed of the rotating shaft A is accurately counted. You will not be able to.

The above inconvenience is caused by the forward and reverse rotation of the rotating shaft A by the continuously driven electric motor, and the forward and reverse rotation of the rotating shaft A, for example, the reciprocating motion of the valve body in the valve, that is, In the electric motor-type actuator which converts into valve opening and valve closing stroke movement, it becomes a problem especially when the valve opening degree of the valve body is calculated | required from the rotation speed of the rotating shaft A using said rotation speed sensor. . That is, in this case, when the chattering phenomenon occurs in the pulse signal from the rotation speed sensor, the rotation speed of the rotation shaft A cannot be counted accurately, and the valve opening degree of the valve body cannot be controlled with high accuracy.

The present invention has been made in view of the above circumstances, and an object thereof is basically to provide a rotation speed sensor suitable for accurately detecting the rotation speed on a rotating body with a simple structure. In an electric motor-type actuator that drives an intake air control valve for controlling intake air of an engine, the rotational speed of the continuously driven electric motor is transmitted to the intake air control valve (intake machine), and the intake air control valve is supplied. When opening and closing, the motor is equipped with a small speed sensor that uses a rotation speed sensor to accurately detect the rotation direction and the rotation speed of the electric motor-type actuator, and is easily attached to a narrow space called an engine intake system. To provide a motorized actuator.

In order to achieve the above object, according to the present invention, there is provided an electric motor-type actuator for driving an intake air control valve of an internal combustion engine, the motor being continuously driven in the forward rotation direction and the reverse rotation direction, and A gear train for transmitting rotational driving force to the intake air control valve to open and close the intake air control valve, and a magnet assembly fixed to an outer circumferential surface of the rotation shaft included in the gear train or the output shaft of the electric motor, so as to surround the outer circumferential surface of the shaft. And the first and second ring magnets having the same shape as each other attached to the outer circumferential surface, and the two ring magnets are arranged side by side adjacent to the outer circumferential surface of the shaft while having a desired interval with respect to the axial direction of the rotating shaft or the output shaft. N poles formed over each of the outer circumferences of the half and S poles formed over the other half of the outer circumference Both ring magnets have a magnet assembly configured to be mounted on the outer circumferential surface by shifting the N and S poles by 90 ° in the circumferential direction of the axis, and when both ring magnets are rotated together with the rotor, A magnetic detecting means for detecting a change in polarity of both ring magnets in a stationary phase of the ring magnet and generating an output, wherein the first ring is fixedly disposed so as to face the outer circumferential surface of the first ring magnet near the outer circumferential surface of the rotating body. The first magnetic probe which outputs a binary signal different from when it faces the N pole of the magnet and when it faces the S pole, and is made in phase with the first magnetic probe in the circumferential direction of the rotating body. The second side of the probe and the rotary shaft or the output shaft are arranged side by side and fixedly disposed so as to face the outer circumferential surface of the second ring magnet in the vicinity of the outer circumferential surface of the rotating body; The electric motor type actuator, characterized in that it includes a magnetic sensing means including a second magnetic probe which outputs a different binary signal at times when the N pole of the magnet and opposed to the S pole and the counter is provided.

According to the rotation speed sensor of the present invention, since half of the outer circumferential surface of the ring magnet is the N pole and the other half of the outer circumferential surface is the S pole, each time the rotating body is rotated half way, it is detected by the magnetic probe. The polarity of one's self is changed alternately. Therefore, as in the case where the magnetic probe is constituted by the Hall IC, the voltage signal from the Hall element becomes a sine wave, unlike the pulsed waveform shown in FIG. Therefore, with this sinusoidal waveform voltage signal, the hysteresis angle defined between the H slice level and the L slice level can be largely secured. Therefore, in the stationary state of the rotating body, the boundary line between the N pole and the S pole of the ring magnet is at the same rotation angle position as that of the magnet B shown in FIG. 13, even if vibration is applied to the rotating body. The vibration of this rotating body can be accommodated in the range of the hysteresis angle mentioned above. As a result, chattering does not occur in the pulse signal output from the magnetic probe. Therefore, by using the rotation speed sensor of the present invention, the rotation speed of the rotating body can be accurately counted based on the pulse signal.

In addition, if the above-mentioned rotation speed sensor is assembled or built into the electric motor-type actuator, the rotation speed of the shaft on which the ring magnet is mounted can be accurately counted by the rotation speed sensor. Positioning of the driven member to be driven can be performed with high accuracy.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the schematic principle of this invention is demonstrated with reference to FIGS.

The rotation speed sensor 20 (more specifically, shown in FIG. 7) according to the present invention is incorporated in the electric motor-type actuator 22 shown in FIGS. 2 and 3, and The motor-actuator 22 is, in the present embodiment, a control valve for controlling an idle speed, i.e., idle speed, of the engine 24 in a motor vehicle, a so-called idle speed control valve (hereinafter, simply referred to as idle speed control valve). It is used to drive the valve body 28 of the 26).

First, the ISCV 26 will be briefly described. The bypass passage 34 is formed in the intake passage 30 of the engine 24 so as to bypass the throttle valve 32, and the bypass passage 34 is formed. ), The above-described ISCV 26 is inserted. When the engine 24 is in the idling operation state, the electronic control device 36 shown in FIG. 3 drives the valve body 28 of the ISCV 26 via the electric motor-type actuator 22. As a result, the ISCV 26 can vary the flow path cross-sectional area of the bypass passage 34. Therefore, by varying the valve opening degree of the valve body 28 in the ISCV 26, the amount of the mixed air supplied to the engine 24 through the bypass passage 34 is adjusted, and based on this adjustment. The idle speed of the engine 24 is controlled to match the target idle speed set according to the operating state of the engine 24.

The target idling speed is the temperature of the cooling water in the engine 24, and when the vehicle is equipped with an air conditioner, an automatic transmission, and a hydraulic pump for power steering, on / off of air conditioning. And the position of the speed change area in the automatic transmission, the hydraulic pump on and off, and the like.

In more detail with respect to the ISCV 26, this ISCV 26 is provided with the housing 38, and only the lower part of this housing 38 is shown by FIG. The lower part of the housing 38 has comprised the hollow cylindrical shape. The inlet port 40 is formed in the side wall in the lower part of the housing 38, and this inlet port 40 is connected to the site | part upstream of the bypass passage 34. As shown in FIG. On the other hand, the outlet port 42 is formed in the bottom wall of the lower part of the housing 38, and this outlet port 42 is connected to the site | part downstream of the bypass passage 34. As shown in FIG.

In the outlet port 42, the inner peripheral edge thereof is formed as a valve seat 44 that cooperates with the valve body 28. From the valve body 28, the valve shaft 45 extends upward, and the valve shaft 45 is freely supported in the axial direction with respect to the bearing 46 fixed in the housing 38. have. Between the bearing 46 and the valve body 28, a valve spring 48 made of an extruded coil spring is disposed so as to surround the valve shaft 45, and the valve spring 48 is a valve body ( 28 is biased toward the valve seat 44. Therefore, the valve body 28 is normally urged by the valve seat 44 under the bias force of the valve spring 48, and closes the outlet port.

As described above, the valve body 28 of the ISCV 26 is driven by the electric motor actuator 22, and the electric motor actuator 22 will be described below.

The electric motor actuator 22 is provided with a feed screw 52 extending upward from the upper end of the valve shaft 45 via the neck 50. The feed screw 52 extends further upward in the same axis as the valve shaft 45. The feed screw 52 includes a worm wheel, that is, a spur gear 54, which is freely disposed in the housing 38. ) Is screwed in. That is, the screw hole 56 is formed in the center part of the worm wheel 54, The feed screw 52 is screwed to the screw hole 56, and penetrates the worm wheel 54. As shown in FIG. In addition, the worm wheel 54 is prevented from moving in the axial direction by fixing means (not shown).

The end face on the bearing 46 side of the worm wheel 54, that is, the worm wheel 54 extends from the lower surface until the cover 58, which has a ring shape, almost reaches the bearing 46. The cover 58 surrounds the feed screw 52 from the outside. Moreover, also in the upper surface of the worm wheel 54, the annular ring 60 protrudes integrally, and this ring 60 has the feed screw 52 which protruded from the upper surface of the worm wheel 54. It surrounds the upper end 62 of the. The cylindrical stopper 64 is fixed to the upper side of the worm wheel 54 in the same axis as the feed screw 52. The lower part of this stopper 64 is formed with the annular part 68 which defines the circular recessed part 66 which has a diameter dimension slightly larger than the diameter dimension of the feed screw 52, and this annular part ( The lower edge 68 is intruded between the ring 60 of the worm wheel 54 and the upper end 62 of the feed screw 52 and surrounds the upper end 62.

The inner end surface of the recess 66 in the stopper 64 is a distance in which the transfer screw 52 moves upward in the axial direction, that is, the distance that the valve body 28 is separated from the valve seat 440. It functions as a limiting stopper surface 70. That is, the stopper surface 70 determines the maximum valve opening degree of the valve body 28.

A worm gear 72 made of a nonmagnetic material is engaged with the worm wheel 54. The worm gear 72 extends in a direction orthogonal to the axis line of the worm wheel 54, and one end of the worm gear 72 has an output shaft (shown in FIG. 76). The electric motor 74 is, in this embodiment, a commutator direct current motor with a conventional brush. Although this type of DC motor is inexpensive, even if it is heated by ambient temperature rise, the characteristic change is small.

On the other hand, the electric motor 74 is electrically connected to the drive circuit 78, and this drive circuit 78 is connected to the above-mentioned electronic control apparatus 36. As shown in FIG.

Although not shown in detail in the drawing, the electric motor 74 and the worm gear 72 are housed in the housing 38 described above.

Therefore, according to the electric motor-type actuator 22 described above, the electric motor 74 is rotated forward or reversely through the drive circuit 78 by the drive signal from the electronic control device 36, and The rotational force of the electric motor 74 is transmitted to the worm wheel 54 via the worm gear 72 to rotate the worm wheel 54. Here, the worm wheel 54 is rotatable, but is attached so that its movement in the axial direction is prevented. Also, since the feed screw 52 is prevented from being rotated by a stopper (not shown), the worm wheel 54 is prevented from rotating. As a result, the feed screw 52 itself moves in the axial direction without rotation. In this way, when the feed screw 52 is moved in the axial direction, the valve body 28 of the ISCV 26 moves away from the valve seat 44 via the neck 50 and the valve shaft 45. Alternatively, the valve seat 44 moves in the seating direction. That is, the valve opening degree of the valve body 28 is variable.

Therefore, when the engine 24 of the vehicle is in the idling operation state, the bypass opening path of the valve body 28 in the ISCV 26 is varied by the electric motor-type actuator 22, so that the bypass passage described above. The amount of the mixer supplied to the engine 24 through the 34 is adjusted, whereby the idle speed of the engine 24 in the idle operation can be controlled.

The control of the idling speed is made such that the actual idling speed matches the target idling speed according to the operation state of the engine 24 at that time. For this purpose, according to the deviation between the target idling speed and the actual idling speed, the ISCV ( It is necessary to vary the valve opening degree of the valve body 28 in 26). Here, the valve opening degree of the valve body 28, that is, the position in the axial direction of the valve body 28 is obtained by counting the rotation speed of the electric motor 74 in the electric motor type actuator 22, Therefore, in the present invention, as described at the beginning of the present description, the rotation speed sensor 20 is assembled to the electric motor-type actuator 22.

The rotation speed sensor 20 is arrange | positioned at the front-end | tip part of the worm gear 72, as apparent from FIG. 3 and FIG. 1 and FIG. That is, at the distal end of the worm gear 72, a rotating shaft portion (rotating body) 8 which rotates integrally with the worm gear 72 and detects the rotational speed thereof is formed. The ring magnet 82 is mounted. The ring magnet 82 is fixed to the rotation shaft portion 80 by a mold material or the like (not shown). Therefore, the ring magnet 82 rotates together with the rotation shaft portion 80. As shown in FIG. 1, the ring magnet 82 has half of its outer circumferential surface magnetized to the N pole, while the other half of its outer circumferential surface is magnetized to the S pole. In addition, in FIG. 1, the other area | region of the magnetic pole is divided and displayed by the broken line so that the area | region of the magnetic pole of the ring magnet 82 becomes clear.

In the vicinity of the outer circumferential surface of the rotary shaft portion 80, a hall IC 84 as a magnetic probe is fixed to the housing 38 and disposed. Here, the hall IC 84 always faces the outer circumferential surface of the ring magnet 82.

When the ring magnet 82 rotates together with the rotating shaft portion 80, if the magnetic pole of the outer circumferential surface of the ring magnet 82, for example, the N pole passes just below the hall IC 84, the hall IC The 84 outputs a voltage signal of a high (H) level, and when the S pole of the ring magnet 82 passes directly below the Hall IC 84, the Hall IC 84 is low. Outputs a voltage signal at (L) level.

The Hall IC 84 described above will be described in more detail. As shown in FIG. 5, the Hall IC 84 detects the magnetism of the ring magnet 82 and detects the analog signal corresponding to the magnetism. And a Hall element 86 for outputting. The analog signal from the Hall element 86 is input to the comparator 88. The comparator 88 outputs a voltage signal of H level when the received analog signal level is equal to or higher than the H slice level. On the other hand, when the received analog signal level is below the L slice level, an L level voltage signal is output. Therefore, the output signal from the comparator 88 becomes the pulse signal P, and this pulse signal P is further provided through the waveform shaping output converter 90, and after the waveform is shaped, the hall IC It is output from the output terminal 92 of 84. Here, the pulse signal P has an H level component P _H and an L level component P _L. The output terminal 92 is connected to the electronic control device 36, as shown in FIG. 3, whereby the pulse signal from the hall IC 84 is supplied to the electronic control device 36. do. In Fig. 5, the waveforms of the outputs from the Hall element 86, the comparator 88, and the waveform shaping output converter 90 are symbolized and displayed, respectively, and reference numerals Vcc and GND are shown. The power supply terminal and the ground terminal are shown respectively.

According to the rotation speed sensor 20 described above, when the ring magnet 82 rotates together with the rotation shaft portion 80 by the electric motor 74, the hall element 86 of the hall IC 84 is a ring magnet. Each time 82 is rotated halfway, the magnetism of the different magnetic poles is alternately detected. Therefore, as shown in FIG. 6, the output from the Hall element 86 is a substantially sinusoidal analog signal ( S). Here, the analog signal S output from the hall element 86 is, as described above, by the comparator 88 and the waveform shaping output converter 90, similarly to the pulse signal P as shown in FIG. ) Is supplied to the electronic controller 36 from the hall IC 84. Component (P _H) of H level of the pulse signal (P) supplied to the electronic control device 36, but the component of the L level (P _L) is counted by a counter in the electronic control device 36, at this time, all of which are, Depending on whether the electric motor 74 is rotated forward or reverse, it is added or subtracted in the counter, and thus, from this calculated value, that is, the rotational speed of the electric motor 74, is transferred to the ISCV 26. The valve opening degree of the valve body 28 in this is calculated | required.

Here, according to the rotation speed sensor 20 of the present invention, half of the outer peripheral surface of the ring magnet 82 is magnetized to the N pole, while the other half of the outer peripheral surface is magnetized to the S pole, so that the rotation shaft portion When the 80 is rotated, as described above, the Hall element 86 of the hall IC 84 outputs the sinusoidal analog signal S as shown in FIG. Compared with the hysteresis angle θ1 in the conventional case as shown in Fig. 2, the hysteresis angle θ2 (about 30 °) can be secured. Therefore, when the rotation of the electric motor 74 is stopped, with respect to the Hall IC 84, the ring magnet 82 is rotated at the rotation angle position shown in FIG. 1, that is, the magnetic pole in the ring magnet 82. When the boundary line X is stopped at the rotation angle position facing the hall IC 84, the level of the voltage signal S from the hall element 86 in the hall IC 84 is set at the sixth intermediate point. As indicated by the Y point, the intermediate value between the H slice level and the L slice level is taken. In this state, even if a vibration lamp or the like is applied to the rotary shaft portion 80, and the rotation angle of the rotary shaft portion 80, that is, the ring magnet 82 is vibrated, this displacement is equal to (1). / 2) rarely become θ2 or more, and the level change of the voltage signal S from the hall element 86 due to the displacement can be suppressed in a range between the H slice level and the L slice level. have. Therefore, the pulse signal P to which the counter in the electronic controller is counted, that is, the pulse signal P including the chattering phenomenon, is not output from the hall IC 84.

Moreover, in the stationary state of the rotating shaft part 80, from the hole IC 84 at the rotation angle position where the boundary line X of the ring magnet 82 was further displaced from the rotation angle position shown in FIG. In the case where the output level of the voltage signal S approaches one of the H slice level and the L slice level, the pulse signal P from the hall IC 84 even if a vibration light is applied to the rotating shaft portion 80. Chattering does not occur. That is, in this case, since the period t3 of the component P _H of the H level or the component P _L of the L level is longer in the pulse signal P, the electronic control apparatus also in this case. The pulse signal P in which the count inside is counted incorrectly, that is, the pulse signal P including the chattering phenomenon, is not output from the hall IC 84.

In addition, according to the rotation speed sensor 20 of the present invention, assuming that the rotating shaft portion 80 is rotating at a constant rotation speed, the components P _H and L of the H level in the pulse signal P are assumed. The period of the component P _L of the level becomes the same period t3 as is apparent from FIG. 6, and this period t3 is compared with the conventional period t2 shown in FIG. 14. It is long enough. Therefore, since the detection of the period (t2) is sufficiently possible, the vibrational displacement of the rotation angle in the rotation shaft portion 80 is such that a chattering phenomenon is generated in the pulse signal P from the hall IC 84, for example. Even if large, considering the rotational speed of the electric motor 74, the pulse interval t1 of the pulse signal P from the hall IC 84 cannot be short, or on the contrary, too long. It is also possible to apply the filter to the pulse signal P such that the filter is ignored from the object of the count, and the above chattering phenomenon can be easily coped with.

In addition, it is apparent that the above-described filter functions effectively even when the voltage signal S from the hall element 86 is adversely affected by the electronic noise from the outside of a broadcasting station or a communication apparatus.

As described above, according to the rotation speed sensor 20 of the present invention, the rotation speed of the rotation shaft portion 80 can be accurately counted with a simple structure, and the rotation speed sensor 20 of the present invention is described above. When built in the electric motor actuator 22 of one ISCV 26, the valve opening degree of the valve body 28 in the ISCV 26 can be detected and controlled with high accuracy.

In addition, in order to detect the valve opening degree of the valve body 28 more accurately, if necessary, the upper end 62 of the transfer screw 52 in the ISCV 26 is brought into contact with the stopper 64 to allow the inside of the electronic control apparatus to be detected. What is necessary is just to reset a counter and to count the rotation speed of the rotating shaft part 80 from this contact state.

In addition, if the number of dimensions of the worm wheel 54 is increased as much as possible, and the pitch of the feed screw 52 is reduced, the valve opening degree of the valve body 28 can be detected and controlled more accurately. none.

In the above description, the case in which the rotational speed sensor 20 is composed of one ring magnet 82 and one Hall element is described schematically. Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 7 to 12. It will be described in detail with reference to.

As is apparent from FIG. 7, the rotational speed sensor 20 of the present invention has a predetermined distance with respect to the axial direction of the rotational shaft portion 80 so as to have a pair of first pairs arranged side by side adjacent to the outer peripheral surface of the shaft. And first and second hole ICs 84a and 84b which are paired with second ring magnets 82a and 82b and these first and second ring magnets 82a and 82b, respectively. It is. Since these first and second ring magnets 82a and 82b, and the first and second hole ICs 84a and 84b are the same as the corresponding ones of the above-described general work, the description thereof will be omitted here. Although not repeated, the first ring magnet 82a and the second ring magnet 82b are mounted on the rotary shaft portion 80 as is apparent from the comparison of FIGS. 8 and 9 in the case of this first embodiment. The rotation angle phase with respect to is shifted by 90 degrees. Further, the second hole IC 84b is arranged in parallel with the first hole IC 84a in the axial direction with respect to the circumferential direction of the rotating shaft portion, and is arranged side by side in the axial direction of the first hole IC and the rotating shaft.

According to the rotation speed sensor 20 of the first embodiment, the first and second pulse signals (1) output from the first and second hole ICs 84a and 84b, respectively, as the rotation shaft 80 rotates. P1) and P2 are as shown in FIG. 10, because the above-mentioned rotation angle phase is 90 degrees different.

Here, when the first and second pulse signals P1 and P2 shown in FIG. 10 are superimposed, from the first and second pulse signals P1 and P2, the rotating shaft portion 80 You can see whether is in forward or reverse rotation. In other words, when the first and second pulse signals P1 and P2 are superimposed and a matching pattern of the pulse signal as shown in FIG. 11 is obtained, the rotation shaft portion 80 rotates forward. In this case, when the H level component of the first pulse signal P1 is output from the first hall IC 84a, the second pulse signal P2 from the second hall IC 84b is an H level component. From then to L level component.

On the other hand, if the rotating shaft portion 80 is reversely rotated, the meshing pattern of the pulse signals from the first and second hole ICs 84a and 84b becomes as shown in FIG. In this case, as is apparent from FIG. 12, when the component of the H level of the first pulse signal P1 is output from the first hall IC 84a, the second pulse signal from the second hall IC 84b ( P2) changes from the L level component to the H level component.

As described above, in the case of the first embodiment, the electronic controller 36 determines whether the pattern of engagement of the pulse signals from the first and second Hall ICs 84a, 84b is the pattern of FIG. 11 or the pattern of FIG. ), It is possible to detect whether the rotating shaft 80, that is, the electric motor 74 is rotating forward or reverse.

In the above embodiment, the Hall IC is used as the magnetic probe, but instead of the Hall IC, an electromagnetic induction type magnetic probe may be used.

Moreover, of course, the rotation speed sensor of this invention is not only limited to the ISCV mentioned above but can also be used for detecting the rotation speed of the rotating body contained in various apparatus.

As described above, according to the rotation speed sensor of the present invention, a magnet fixed to the outer circumferential surface of the rotating body to detect the rotational speed is made into a ring magnet, and half of the outer circumferential surface of the ring magnet is made an N pole. Since the outer circumferential surface of the other half is set to the S pole, each time the rotating body is rotated halfway, the polarity of the magnet detected by the magnetic probe changes alternately. Therefore, by detecting the magnetism of such a ring magnet, the pulse signal output from the magnetic probe is less likely to be adversely affected by chattering caused by vibration of the rotor even when the rotor is stationary, and the rotation of the rotor The number can be detected accurately.

Further, the first and second ring magnets are attached to the outer circumferential surface while being arranged side by side in the axial direction of the rotating shaft or the output shaft of the motor, and the first and second hole ICs, that is, the magnetic probes, are arranged in the axial direction. Since the sensor output from the magnetic probe is detected from the same direction referred to as the axial direction, the sensor output can be drawn out in the same direction as the engine compartment by wiring in the same direction, so that the sensor output from the magnetic probe is detected from the same direction. The structure of the whole hand sensor can be miniaturized.

In addition, when the above-mentioned rotation speed sensor is incorporated into an electric motor-type actuator for driving an intake air control valve of an internal combustion engine, the position of the intake air control valve can be detected simply and accurately from the rotation speed of the electric motor. Positioning control of the air control valve can be performed with high accuracy.

In addition, since the rotation speed sensor of the present invention has a simple structure, it is possible to detect the rotation speed included in various devices, that is, the rotation speed of the rotation shaft, and thus the application field becomes wider.

Claims (1)

In an electric motor type actuator for driving an intake air control valve of an internal combustion engine, an electric motor 74 which is continuously driven in a forward rotation direction and a reverse rotation direction, and the rotational driving force of the electric motor are supplied to the intake air control valve ( 28, a gear train (72, 54, 52) for opening and closing the intake air control valve and a magnet assembly fixed to the outer circumferential surface of the rotation shaft included in the gear train or the output shaft of the electric motor, the outer peripheral surface of the shaft The first and second ring magnets 82a and 82b having the same shape, which are attached to the outer circumferential surface so as to surround each other, and the two ring magnets have a desired distance with respect to the axis direction of the rotating shaft or the output shaft. They are arranged side by side adjacent to the outer circumference, and have N poles formed over each half of the outer circumferential surface and S poles formed over the other half of the outer circumferential surface, and both ring magnets A magnet assembly configured to be mounted on the outer circumferential surface with each of the N and S poles shifted by 90 ° in the circumferential direction of the axis, and both rings in a specific fixed phase when both ring magnets are rotated together with the rotating body. In the magnetic detection means for detecting the change in the polarity of the magnet and generating the output, the magnetic detection means is fixedly disposed so as to face the outer circumferential surface of the first ring magnet near the outer circumferential surface of the rotating body so as to face the N pole of the first ring magnet. And the first magnetic probe 84a for outputting a different binary signal in response to the S pole and in phase with the first magnetic probe in the circumferential direction of the rotating body so that the first magnetic probe and the rotating shaft or It is arranged side by side in the axial direction of the output shaft, and fixedly arranged so as to face the outer peripheral surface of the second ring magnet at the vicinity of the outer peripheral surface of the rotating body is always N of the second ring magnet An electric motor-type actuator comprising magnetic detecting means including a second magnetic probe (84b) for outputting a binary signal which is different depending on when it faces the pole and when it faces the S pole.

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