JP2009281856A - Rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation sensor capable of preventing positional deviation of a magnetic sensor section by contriving a point for fixing a position of the magnetic sensor section in a holder. <P>SOLUTION: This rotation sensor 1 which has, in the holder 3, the magnetic sensor section 4 for detecting change in magnetism due to rotation of a rotary body and cables 5 connected to terminals 42p, 42s, 42x, 42y of the magnetic sensor section 4 so as to detect the rotation of the rotary body includes a decoupling prevention means 10 which is provided in the holder 3 so as to prevent decoupling of the magnetic sensor section 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotation sensor that detects rotation of a rotating body from a change in magnetism caused by the rotation of the rotating body.

  As a rotation sensor that detects the rotation of a rotating body from a change in magnetism due to the rotation of the rotating body, there is a sensor that uses a magnetic sensor. As a magnetic sensor, there is a combination of a permanent magnet and a magnetic IC such as a Hall IC. Magnetic ICs have built-in magnetic sensitive elements such as Hall elements that change the amount of electricity such as voltage in response to changes in magnetism, and an electronic circuit that outputs the amount of electricity from the magnetically sensitive elements as an electrical signal. ing.

  In such a rotation sensor, a permanent magnet and a magnetic IC are arranged facing a rotating body (for example, a magnetic encoder) made of a magnetic material such as Fe, and the magnetic flux density due to the magnetic field of the permanent magnet is affected by the rotation of the rotating body. And sensed by the magnetic sensitive element.

  When actually assembling this type of rotation sensor, various parts such as a permanent magnet, a magnetic IC, a resin holder for housing these, and a cable for transmitting an output signal of the magnetic IC are supported by the rotating shaft. It must be fixed to a fixed object such as the bearing body.

  Furthermore, since the rotation sensor detects the rotation of the rotating body with a magnetic IC, the magnetic IC must be installed facing the sensing point of the rotating body, and positioning of the magnetic IC is important.

  For example, in the conventional rotation sensor 71 shown in FIGS. 7A and 7B, a resin holder 73 is provided at the end of an annular metal fitting 72 fitted to the outer cylinder of the bearing, and the holder 73 has an IC. A positioning bag-like space 74 is formed and inserted so that the package of the Hall IC 75 is abutted against the tip of the space 74 (the left end which is the back side in FIGS. 7A and 7B). The terminal portion of the cable 76 is fitted into the holder 73, and the Hall IC 75 and the cable 76 are positioned and fixed and connected.

  The prior art document information related to the invention of this application includes the following.

JP 2008-26262 A JP 2001-315501 A JP 2003-254985 A JP 2005-265826 A JP 2002-213472 A

  However, in the conventional rotation sensor 71, it is difficult to know whether or not the tip of the Hall IC 75 that should have been positioned is in contact with the tip of the space 74, and the position of the Hall IC 75 is shifted before the cable 76 is fitted into the holder 73. there is a possibility.

  Further, the cable 76 may be pulled when the rotation sensor 71 is installed or used, so that the position of the Hall IC 75 may be shifted.

  When the position of the Hall IC 75 is shifted, the detection accuracy of the rotation of the rotating body is lowered, or the control means or the computer connected to the cable 76 malfunctions.

  Accordingly, an object of the present invention is to devise a point for fixing the position of a magnetic sensor unit in a holder, and to provide a rotation sensor that prevents a position shift of the magnetic sensor unit.

  In order to achieve the above object, the present invention provides a magnetic sensor unit for detecting a change in magnetism due to rotation of a rotating body in a holder, a cable is connected to a terminal of the magnetic sensor unit, and the rotating body In the rotation sensor for detecting the rotation of the magnetic sensor, the rotation sensor is provided in the holder, and includes a removal prevention means for preventing the magnetic sensor unit from coming off.

  The removal preventing means may be formed by melting a part of the holder with heat caulking or ultrasonic caulking and curing the holder, and fixing an excess terminal of the magnetic sensor unit to the holder.

  The drop prevention means may be formed of hooks provided on both sides of the holder and engaged with the upper end of the magnetic sensor unit.

  The magnetic sensor unit is composed of a Hall IC having four terminals arranged in parallel, the cable has a power line and a signal line, and the power line and the signal line are separated on the inner bottom surface of the holder. It is preferable that a separation protrusion for mounting is formed, and two surplus terminals inside the Hall IC are abutted against a wall surface on the sensor side of the separation protrusion.

  According to the present invention, it is possible to prevent displacement of the magnetic sensor unit.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, the entire configuration of the rotation sensor will be described with reference to FIGS.

  As shown in FIGS. 2 to 5, the rotation sensor 1 according to the present embodiment includes an annular metal fitting (core metal) 2 made of a metal such as Fe that is fitted into an outer cylinder of a bearing, and a peripheral edge of the metal fitting 2. A resin holder 3 provided in the unit, a magnetic sensor unit 4 that is accommodated in the holder 3 and detects the rotation of the rotating body 7 from the change in magnetism due to the rotation of the rotating body 7, and a terminal unit is provided in the holder 3. It is mainly composed of a cable 5 that is housed and transmits an output signal from the magnetic sensor unit 4.

  A rotating shaft 6 is inserted through the center of the metal fitting 2, and a rotating body 7 that rotates integrally with the rotating shaft 6 is provided outside the rotating shaft 6 and inside the metal fitting 2. Since the metal fitting 2 is caulked and attached to the outer cylinder of the bearing, the metal fitting 2 has a large diameter portion 2b and a small diameter portion 2s, and the outer peripheral portion is formed in a stepped shape in a longitudinal sectional view. A through hole 8 is formed in the large diameter portion 2 b of the metal fitting 2 so as to penetrate the large diameter portion 2 b in the axial direction and substantially along the tangential direction of the mold 2.

  The holder 3 accommodates the magnetic sensor part 4 and the terminal part of the cable 5, one end of the holder 3 is in close contact with the outer peripheral surfaces of the large diameter part 2 b and the small diameter part 2 s of the metal fitting 2, and the through hole 8. Is provided so as to straddle the inside and outside of the metal fitting 2.

  The holder 3 includes a lower holder 3d and a cap 3u that covers the lower holder 3d and protects the magnetic sensor portion 4 and the end portion of the cable 5. The lower holder 3d is formed in a substantially T shape in plan view, and is formed integrally with the wide portion 3w, which is a wide portion extending along the tangential direction of the metal fitting 2, and the wide portion 3w. A narrow portion 3n that is a narrow portion extending along the outer side (in the end portion of the cable 5 along the longitudinal direction of the cable 5). The lower holder 3d is manufactured in close contact with the metal fitting 2 by setting the metal fitting 2 in a resin mold for forming the holder, pouring the resin into the through hole 8 of the metal fitting 2, and curing the resin.

  The magnetic sensor unit 4 is accommodated in the holder 3 so that the sensing axis is along the radial direction of the metal fitting 2. One end of the cable 5 is connected to the magnetic sensor unit 4 in the holder 3, and the other end of the cable 5 is connected to a control means for controlling each component of the device and an external device such as a computer. In the present embodiment, a gear-like magnetic encoder is used as the rotating body 7.

  FIG. 1A is a plan view showing an internal configuration of a main part of a rotation sensor which is a preferred first embodiment of the present invention, and FIG. 1B is a sectional view taken along line 1B-1B.

  As shown in FIGS. 1 (a) and 1 (b), the rotation sensor 1 according to the first embodiment has a holder 3 provided with an anti-disengagement means 10 for preventing the magnetic sensor unit 4 from coming off. It is.

  The top surface of the package of the magnetic sensor unit 4 (the left end surface of the magnetic sensor unit 4 in FIGS. 1A and 1B) is abutted against one end of the wide part 3w of the lower holder 3d to magnetically A positioning recess 12 for positioning the sensor unit 4 and accommodating the top of the package of the magnetic sensor unit 4 in the holder 3 is formed.

  Therefore, to prevent the magnetic sensor unit 4 from coming off here is to substantially fit the magnetic sensor unit 4 with the top of the package of the magnetic sensor unit 4 during assembly, installation, and use of the rotation sensor 1. This means that the magnetic sensor unit 4 is prevented from being displaced from the recess 12 after being positioned by the recess 12 having the shape and accommodated in the holder 3.

  The magnetic sensor unit 4 uses a magnetic IC having at least three terminals. In the present embodiment, a Hall IC 41 having four terminals arranged in parallel is used as the magnetic IC (magnetic sensor unit 4). The Hall IC 41 includes a Hall element as a magnetically sensitive element and an electronic circuit that processes the amount of electricity from the Hall element and outputs it as an electrical signal. The built-in electronic circuit includes an OP amplifier, its offset removal circuit, an output buffer, an A / D converter, and the like. The Hall IC 41 is accommodated in the holder 3 such that four parallel terminals are substantially along the radial direction of the metal fitting 2.

  The cable 5 includes a power supply line 5 p that supplies power to the magnetic sensor unit 4 and a signal line 5 s that transmits an output signal from the magnetic sensor unit 4. In order to give the cable 5 high flexibility and mechanical strength, the power supply line 5p and the signal line 5s are made of a conductor 13 formed by twisting a plurality of small-diameter strands (insulated with the power supply line 5p and the signal line 5s). (Difference) 14 is covered. When the power supply line 5p and the signal line 5s are arranged and covered with the sheath 15, the cable 5 is obtained. The outer diameter of the cable 5 is about 3 to 6 mm.

  Of the two outer terminals of the Hall IC 41, one terminal 42p is a power terminal connected to the terminal conductor 13 of the power line 5p, and the other terminal 42s is the terminal conductor 13 of the signal line 5s. Is a signal line terminal (output terminal) connected to. The inner two terminals 42x and 42y of the Hall IC 41 are terminals for monitoring the waveform of the output signal, but are unnecessary terminals for the rotation sensor 1 and are not connected to the cable 5.

  On one end of the wide portion 3w of the lower holder 3d, one end communicates with the recess 12 and a sensor receiving groove 16 for receiving the magnetic sensor portion 4 is formed. From the other end of the wide portion 3w of the lower holder 3d to one end of the narrow portion 3n, the other end of the sensor receiving groove 16 is provided, and the four terminals 42p, 42s, 42x, A terminal mounting portion 17 on which 42y is mounted is formed.

  One end of the terminal mounting portion 17 is formed one step higher than the sensor receiving groove 16, the center portion on which the terminals 42x and 42y are mounted is flat, and both side portions on which the terminals 42p and 42s are mounted are the other. It forms so that it may become the inclined surface which becomes low toward an edge part. The terminal mounting portion 17 is formed with four terminal fitting grooves 18 into which the terminals 42p, 42s, 42x, and 42y are fitted.

  The inner bottom surface on the other end side of the holder 3 is a cable mounting surface for mounting the cable 5 subjected to terminal processing. A separation projection 19 for separating and placing the power supply line 5p and the signal line 5s of the terminal-processed cable 5 is formed on the center of one end of the narrow part 3n of the lower holder 3d. One end of the separation protrusion 19 is formed wider than the distance between the terminals 42x and 42y, and the other end is formed at the tip.

  Both sides of one end of the narrow portion 3n of the lower holder 3d are separation mounting portions 20 for mounting the separated power supply line 5p and signal line 5s. The separation mounting portion 20 is formed so that one end portion is formed one step lower than the terminal mounting portion 17 and has an inclined surface that is lowered toward the other end portion.

  At the other end of the lower holder 3d, a sheath fitting groove 21 into which the sheath 15 of the cable 5 is fitted is formed at a level lower than the separation mounting portion 20.

  The drop prevention means 10 of the rotation sensor 1 is provided on the terminal mounting portion 17 positioned between the sensor receiving groove 16 of the lower holder 3d and the separation protrusion 19 in advance as a part of the lower holder 3d (for example, a protrusion). Part), the magnetic sensor part 4 is positioned by the concave part 12 of the lower holder 3d and placed in the sensor receiving groove 16, and then the pre-detachment prevention part is subjected to a heat treatment so that the pre-detachment prevention part is heat caulked. These are melted (crushed) and cured to form the drop prevention portion 22.

  By means of this drop prevention part 22, the terminals 42x, 42y of the magnetic sensor part 4 are fixed on the terminal mounting part 17 located between the sensor receiving groove 16 of the lower holder 3d and the separation projection 19 so that the lower holder 3d The magnetic sensor unit 4 is fixed. Alternatively, the pre-prevention preventing portion 22 may be formed by irradiating the pre-prevention prevention portion with ultrasonic waves, melting the pre-prevention prevention portion with ultrasonic caulking, and curing it.

  Further, in the rotation sensor 1, when the magnetic sensor unit 4 is placed in the sensor receiving groove 16, the terminal lengths of the terminals 42 x and 42 y are adjusted by cutting, and the sensor side wall surface which is one end surface of the separation protrusion 19. At 19 s, the tips of the terminals 42 x and 42 y of the magnetic sensor unit 4 are brought into contact with each other.

  On the other hand, when the rotation sensor 1 is assembled, the cable 5 is terminated, the power supply line 5p, the conductor 13 of the signal line 5s and the insulator 14 are exposed, and the cable 5 is placed on the lower holder 3d. After each conductor 13 is ultrasonically welded to integrate a plurality of strands, each conductor 13 is welded or soldered to the terminals 42p and 42s of the magnetic sensor unit 4 fixed to the lower holder 3d.

  Thus, since the rotation sensor 1 is provided with the removal prevention means 10 for preventing the magnetic sensor unit 4 from coming off in the holder 3, the rotation sensor 1 is positioned in the recess 12 of the lower holder 3 d and placed in the sensor receiving groove 16. The magnetic sensor unit 4 can be reliably fixed on the lower holder 3d.

  Therefore, according to the rotation sensor 1, even when the rotation sensor 1 is assembled, installed, and used, the position of the magnetic sensor unit 4 is maintained even when the cable 5 is pulled in the opposite direction (longitudinal direction of the cable 5). Is fixed, and the magnetic sensor unit 4 can be prevented from slipping out of the recess 12.

  Further, in the rotation sensor 1, the tips of the terminals 42 x and 42 y of the magnetic sensor unit 4 are abutted against the sensor-side wall surface 19 s that is one end surface of the separation protrusion 19, so that the magnetic sensor unit 4 is positioned from the recess 12. It can prevent more effectively that it slips out.

  Furthermore, since the rotation sensor 1 is provided with the terminal fitting groove 18 in which the middle of each of the terminals 42p, 42s, 42x, and 42y is formed in the terminal mounting portion 17 of the lower holder 3d. The placement of the terminals 42p, 42s, 42x, and 42y is simplified, and the positioning of the magnetic sensor unit 4 is also simplified.

  Next, a second embodiment will be described.

  As shown in FIGS. 6A and 6B, the rotation sensor 61 according to the second embodiment is provided with both sides of the other end portion of the sensor receiving groove 16 as the slip-off preventing means 60, and is a magnetic sensor. What consists of the hooks 62a and 62b engaged with the upper end part (upper end part of a package) of the part 4 is used.

  Each of the hooks 62a and 62b includes an upright portion 63 that rises from the inner bottom surface of the sensor receiving groove 16, and a key-like portion 64 that is bent from the upright portion 63 toward one end of the lower holder 3d.

  When the rotation sensor 61 is assembled, the base end portion of the package of the magnetic sensor unit 4 is set on the hooks 62a and 62b, and then the front end of the package is inserted into the recess 12 while pushing the magnetic sensor unit 4 from above. By placing the magnetic sensor unit 4 in the groove 16, the hooks 62 a and 62 b are engaged with the upper end of the magnetic sensor unit 4.

  Thereby, according to the rotation sensor 61, it can fix reliably, simultaneously with positioning the magnetic sensor part 4 on the lower holder 3d.

  The rotation sensor according to the present embodiment is useful when used for an anti-lock brake system (ABS) sensor or a vehicle speed sensor provided in a vehicle such as an automobile. For example, in the ABS sensor, since the cable 5 is exposed to the outside air, the cable 5 may be pulled because mud or snow adheres to the cable 5 or a temperature difference occurs around the cable 5. Even in such a case, in the rotation sensor according to the present embodiment, the positional deviation of the magnetic sensor unit 4 can be prevented, and the reliable operation of the ABS can be guaranteed.

  When the rotation sensor according to the present embodiment is used for an ABS sensor, the magnetic sensor unit 4, the permanent magnet, and the coil are placed in the holder 3 even in the active method in which the magnetic sensor unit 4 and the permanent magnet are accommodated in the holder 3. May be a passive system that accommodates and operates. Further, the rotary body 7 may be of a type using a multipolar magnet ring in which a plurality of permanent magnets are arranged by alternately exposing the N pole and the S pole on the peripheral surface thereof.

  As the magnetic sensor unit 4, an MRIC having a magnetoresistive (MR) element may be used.

  In addition, the present embodiment is merely an example, and the removal prevention means in the present invention may be that the magnetic sensor unit does not completely come out from the top of the package of the magnetic sensor unit or the recess that accommodates the entire package. As a result, it is only necessary that the magnetic sensor unit is fixed at a predetermined position of the recess.

FIG. 1A is a plan view showing an internal configuration of a main part of a rotation sensor which is a preferred first embodiment of the present invention, and FIG. 1B is a sectional view taken along line 1B-1B. It is a top view which shows the whole structure of the rotation sensor shown in FIG. It is a reverse view which shows the whole structure of the rotation sensor shown in FIG. It is a longitudinal cross-sectional view (4A-4A sectional view taken on the line of FIG. 5) which shows an example of the use condition of the rotation sensor shown in FIG. FIG. 5 is a view taken in the direction of arrows 5A in FIG. 4. FIG. 6A is a plan view showing the internal configuration of the main part of the rotation sensor according to the second embodiment of the present invention, and FIG. 6B is a sectional view taken along line 6B-6B. Fig.7 (a) is a top view which shows the principal part of the conventional rotation sensor, FIG.7 (b) is the 7B-7B sectional view taken on the line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotation sensor 2 Metal fitting 3 Holder 4 Magnetic sensor part 5 Cable 10 Disconnection prevention means

Claims (4)

  A rotation sensor for detecting a rotation of the rotating body by housing a magnetic sensor section for detecting a change in magnetism due to rotation of the rotating body, connecting a cable to a terminal of the magnetic sensor section, provided in the holder A rotation sensor comprising a removal prevention means for preventing the magnetic sensor unit from coming off.   2. The rotation sensor according to claim 1, wherein the removal preventing means is formed by melting and curing a part of the holder with heat caulking or ultrasonic caulking, and fixing an excess terminal of the magnetic sensor unit to the holder.   2. The rotation sensor according to claim 1, wherein the drop-off prevention means includes hooks that are provided on both sides of the holder and engage with an upper end portion of the magnetic sensor unit.   The magnetic sensor unit is composed of a Hall IC having four terminals arranged in parallel, the cable has a power line and a signal line, and the power line and the signal line are separated on the inner bottom surface of the holder. The rotation sensor according to any one of claims 1 to 3, wherein a separation protrusion for mounting is formed, and two surplus terminals inside the Hall IC are abutted against a wall surface on the sensor side of the separation protrusion. .

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