JP2010243284A - Rotary torque detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus which achieves low-cost, sure rotary torque detection in a rotary torque detection apparatus for use in detecting the rotary torque of mainly automobile steering. <P>SOLUTION: Each of a plurality of magnets 22 is formed in nearly an arc shape. The magnets 22 are fixed to a first rotating body 21 at predetermined intervals. By providing the nearly arc-shaped magnets 22 at predetermined positions of the first rotating body 21 facing a first magnetic body 5 and a second magnetic body 6 of which the magnetism is detected by a magnetic detection element 9, the rotary delay of a second rotating body 4 with respect to the first rotating body 21 is detected with a small amount of magnet as a whole volume, providing a rotary torque detection apparatus which achieves sure rotary torque detection by a low-cost structure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotational torque detecting device mainly used for detecting rotational torque of a steering wheel of an automobile.

  In recent years, with the advancement of advanced functions of automobiles, various rotational torque detectors and rotational angle detectors are used to detect the rotational torque and rotational angle of the steering and perform various controls of the vehicle such as a power steering device and a brake device. Things are increasing.

  Such a conventional rotational torque detection device will be described with reference to FIGS.

  FIG. 10 is a cross-sectional view of a conventional rotational torque detector, FIG. 11 is an exploded perspective view thereof, and in FIG. 10, 1 is a substantially cylindrical first rotating body that rotates in conjunction with steering, and 2 is a substantially cylindrical shape. A magnet 2, 3 is a substantially cylindrical holding body, and a magnet 2 in which N poles and S poles are alternately formed on the entire circumference at an angular interval of, for example, about 20 to 40 degrees is an outer periphery of the first rotating body 1. While being fixed to the lower end, the holding body 3 covers the first rotating body 1.

  4 is a substantially cylindrical second rotating body, 5 is a first magnetic body having a plurality of protrusions 5A formed on the inner periphery, and 6 is a second magnetic body having a plurality of protrusions 6A formed on the inner periphery. The second rotating body 4 is disposed below the first rotating body 1 and the first magnetic body 5 and the second magnetic body 6 are opposed to the magnet 2 via the spacer 7. The second rotary body 4 is fixed to the upper end.

  Reference numeral 8 denotes a wiring board disposed horizontally on the sides of the first rotating body 1 and the second rotating body 4, and a plurality of wiring patterns (not shown) are formed on the upper and lower surfaces, and the magnet 2 Is mounted between the first magnetic body 5 and the second magnetic body 6, and a magnetic detection element 9 such as a Hall element is mounted on the opposite surface.

  Further, the control means 10 connected to the magnetic detection element 9 is formed on the wiring board 8 by electronic parts such as a microcomputer, and between the first rotating body 1 and the second rotating body 4, A substantially columnar connecting body 11 such as a torsion bar is provided with a top end fixed to the first rotating body 1 and the holding body 3 and a lower end fixed to the second rotating body 4 by pins (not shown). Yes.

  In addition, 12 is a substantially box-shaped upper case made of insulating resin, 13 is also a lower case, and in the upper case 12 and the lower case 13, the first rotating body 1, the second rotating body 4, and the first magnetic The body 5, the second magnetic body 6, the wiring board 8, and the like are housed, and the upper ends of the first rotating body 1 and the holding body 3 are from the opening holes on the lower surface of the lower case 13 from the opening holes on the upper case 12. The lower end of the second rotating body 4 protrudes in a rotatable manner to constitute a rotational torque detecting device.

  Such a rotational torque detection device is mounted on the first rotary body 1 and the second rotary body 4 together with the rotation angle detection device and the like, and is mounted below the steering wheel of the automobile. The means 10 is connected to an electronic circuit (not shown) of the automobile body through a connector, a lead wire (not shown) or the like.

  In the above configuration, when the steering wheel is rotated, the first rotating body 1 rotates along with this, and after the connecting body 11 is twisted, the second rotating body 4 is slightly delayed from the first rotating body 1. At this time, for example, the rotational torque is small when the vehicle is traveling, so that the delay in the rotation of the second rotating body 4 with respect to the first rotating body 1 is small, and the rotational torque is large when the vehicle is stopped. The delay in rotation of the body 4 increases.

  At this time, the rotation delay of the second rotating body 4 with respect to the first rotating body 1 is about 1 degree as an angle when the rotational torque is small, and around 4 degrees when the rotational torque is large. Become.

  And with rotation of this 1st rotary body 1 and the 2nd rotary body 4, the magnet 2 fixed to these, and the 1st magnetic body 5 and the 2nd magnetic body 6 are somewhat behind this, too. The magnetism detecting element 9 causes the first magnetic body 5 and the second magnetic body 6 to project the protrusions 5A and 6A by rotating and rotating the magnets N and S poles alternately formed at predetermined intervals. This is input to the control means 10.

  At this time, the magnetism detected by the magnetism detecting element 9 is the second magnetic material 5 and the second magnetic material 6 fixed to the first rotating body 1 to which the magnet 2 is fixed. When the rotation delay of the rotating body 4 is small, the magnetism is weak, and when the rotation delay is large, the magnetism is strong.

  Then, the control means 10 calculates the rotational torque of the steering from the strength of the magnetism of the magnetic detection element 9 detected through the first magnetic body 5 and the second magnetic body 6, and this is the electronic torque of the automobile body. Output to the circuit, and the electronic circuit calculates various data from the rotational torque, the rotational angle of the steering wheel, the speed sensor mounted on each part of the vehicle body, etc. Control is performed.

  In other words, for example, when the vehicle is running and the steering torque is small, the power steering device is loosened so that the steering wheel is rotated with a heavy force, and the vehicle stops and the steering wheel rotates. When the torque is large, the power steering device is used greatly, and the steering wheel can be rotated even with a light force.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2007-256140 A

  However, in the conventional rotational torque detection device, in order to detect a delay in rotation of the second rotating body 4 with respect to the first rotating body 1 around 4 degrees as an angle, Since the magnet 2 in which the N pole and the S pole are alternately formed at a predetermined interval is used, there is a problem that the apparatus becomes expensive.

  The present invention solves such a conventional problem, and an object of the present invention is to provide a rotational torque detection device capable of reliably detecting rotational torque with an inexpensive configuration.

  In order to achieve the above object, the present invention forms a rotational torque detecting device by forming magnets in a substantially arc shape and fixing the plurality of magnets to a first rotating body at a predetermined interval. By providing a plurality of substantially arc-shaped magnets only at predetermined locations of the first rotating body, which are opposed to the first magnetic body and the second magnetic body, where the detection element detects magnetism, Since the rotation delay of the second rotating body relative to the first rotating body can be detected with a small amount of magnets, a rotational torque detecting device capable of reliably detecting rotational torque can be obtained with an inexpensive configuration. It has an action.

  As described above, according to the present invention, it is possible to obtain an advantageous effect that it is possible to realize a rotational torque detection device that can detect rotational torque reliably and inexpensively.

Sectional drawing of the rotational torque detection apparatus by one embodiment of this invention Exploded perspective view Partial perspective view Side view of the same part Partial perspective view Partial perspective view according to another embodiment Side view of the same part Partial perspective view Side view of the same part Sectional view of a conventional rotational torque detector Exploded perspective view

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  In addition, the same code | symbol is attached | subjected to the part of the structure same as the structure demonstrated in the term of background art, and detailed description is simplified.

(Embodiment)
FIG. 1 is a cross-sectional view of a rotational torque detector according to an embodiment of the present invention, FIG. 2 is an exploded perspective view thereof, in which 21 is a substantially cylindrical shape, such as polybutylene terephthalate that rotates in conjunction with steering 1 is a first rotating body made of an insulating resin, 22 is a substantially arc-shaped magnet such as a ferrite or Nd-Fe-B alloy, and 3 is a substantially cylindrical holding body made of an insulating resin such as polybutylene terephthalate. The magnet 22 is fixed to the flange portion 21 </ b> A at the lower end of the outer periphery of the first rotating body 21 at a predetermined interval, and the holding body 3 covers the first rotating body 21.

  In addition, as shown in the partial perspective view of FIG. 3, the substantially arc-shaped magnet 22 has N poles and S poles adjacent to each other in two rows, and has a predetermined center with respect to the rotation center of the first rotating body 21. The flange 21A of the rotating body 21 is formed with a width corresponding to the angle α, and a plurality of protrusions 21B having a width corresponding to a predetermined angle β with respect to the rotation center and a predetermined interval between the protrusions 21B. A plurality of formed recesses 21C are provided, and for example, six magnets 22 are fixed in the recess 21C by bonding or the like.

  That is, for example, the angle α that is the width of the magnet 22 is formed to a width of 40 degrees with respect to the rotation center of the first rotating body 21, and the angle β that is the width of the protruding portion 21B of the flange portion 21A is When formed with a width of 20 degrees with respect to the rotation center, the ratio of the plurality of magnets 22 to the total volume is only 2/3, and the volume of the magnets 22 is equal to the volume of the protrusion 21B. It is becoming less.

  In addition, 4 is a substantially cylindrical second rotating body made of an insulating resin such as polybutylene terephthalate, 5 is a substantially ring-shaped first magnetic body such as permalloy, iron, Ni-Fe alloy, and 6 is a second rotating body. The second rotating body 4 is disposed below the first rotating body 21 and a plurality of tongue-like protrusions 5A are provided on the inner periphery of the first magnetic body 5. A plurality of projecting portions 6A, for example, six each are formed on the inner periphery of the magnetic body 6.

  Furthermore, 7 is a substantially ring-shaped spacer made of copper, aluminum, or insulating resin. The first magnetic body 5 and the second magnetic body 6 are opposed to the magnet 22 via the spacer 7 and are rotated in the second direction. Each is fixed to the upper end of the body 4.

  Reference numeral 8 denotes a wiring board such as paper phenol or glass epoxy, and a plurality of wiring patterns (not shown) are formed on the upper and lower surfaces, and the side of the first rotating body 21 and the second rotating body 4. Is arranged horizontally between the first magnetic body 5 and the second magnetic body 6 on the surface facing the magnet 22, and detects the vertical magnetism and the horizontal element. A plurality of magnetic detection elements 9 such as GMR elements for detecting magnetism are mounted and mounted.

  Further, the control means 10 connected to the magnetic detection element 9 is formed on the wiring board 8 by electronic components such as a microcomputer, and a pin is provided between the first rotating body 21 and the second rotating body 4. (Not shown) or the like is provided with a substantially cylindrical connection body 11 such as a torsion bar whose upper end is fixed to the first rotating body 21 or holding body 3 and whose lower end is fixed to the second rotating body 4. It has been.

  Furthermore, 12 is a substantially box-shaped upper case made of an insulating resin such as polybutylene terephthalate, and 13 is also a lower case. The first rotating body 21 and the second rotating body 4 are provided in the upper case 12 and the lower case 13. The first magnetic body 5, the second magnetic body 6, the wiring board 8, and the like are accommodated, and the upper end of the first rotating body 21 and the holding body 3 are connected to the lower case 13 from the opening hole on the upper surface of the upper case 12. The lower end of the second rotating body 4 protrudes from the opening hole on the lower surface so as to be rotatable, thereby constituting a rotational torque detecting device.

  Such a rotational torque detector is mounted on the first rotating body 21 and the second rotating body 4 together with the rotational angle detecting device and the like, and is mounted below the steering wheel of the automobile, and is controlled. The means 10 is connected to an electronic circuit (not shown) of the automobile body through a connector, a lead wire (not shown) or the like.

  In the above configuration, when the steering wheel is rotated, the first rotating body 21 is rotated with the rotation of the steering wheel, and after the connecting body 11 is twisted, the second rotating body 4 is slightly delayed from the first rotating body 21. At this time, for example, since the rotational torque is small when the vehicle is traveling, the rotation delay of the second rotating body 4 with respect to the first rotating body 21 is small, and the rotational torque is large when the vehicle is stopped. The delay in rotation of the body 4 increases.

  Along with the rotation of the first rotating body 21 and the second rotating body 4, the plurality of magnets 22 fixed to these, and the first magnetic body 5 and the second magnetic body are slightly delayed. 6 also rotates, and the magnetic detection element 9 detects the magnetic change of the N pole and the S pole of the plurality of magnets 22 through the first magnetic body 5 and the protrusions 5A and 6A of the second magnetic body 6. This is input to the control means 10.

  That is, when the steering wheel is not rotated and is in a neutral position and the vehicle is in a straight traveling state, a plurality of protrusions on the inner periphery of the first magnetic body 5 as shown in the partial side view of FIG. 5A and the center of the plurality of protrusions 6A on the inner periphery of the second magnetic body 6 are respectively located at the centers of the north and south poles of the magnet 22, so that the magnetic force is balanced and the first magnetism No magnetic flux is generated between the body 5 and the second magnetic body 6, and the magnetism detected by the magnetic detection element 9 disposed between them is zero.

  On the other hand, the steering wheel is rotated rightward, for example, and the first magnetic body 5 and the second magnetic body 6 start to rotate with a slight delay with respect to the magnet 22 as shown in FIG. Then, since the protruding portion 5A has an N-pole and the lower protruding portion 6A has an S-polarity, a magnetic flux in the direction from the first magnetic body 5 to the second magnetic body 6 is generated, and this magnetism is magnetized. The detection element 9 detects and a voltage corresponding to the strength of magnetism is output to the control means 10.

  At this time, the rotation delay angle θ of the second rotating body 4 with respect to the first rotating body 21 is about 1 degree when the rotational torque is small, and about 4 degrees when the rotational torque is large. Become.

  On the contrary, when the steering wheel is rotated leftward, on the contrary, the protruding portion 5A has the S pole, and the lower protruding portion 6A has the N pole. Magnetic flux in the direction from the magnetic body 6 to the first magnetic body 5 is generated, and this magnetism is detected by the magnetic detection element 9.

  Then, the control means 10 calculates the rotational torque of the steering shaft from the strength of the magnetism of the magnetic detection element 9 detected via the first magnetic body 5 and the second magnetic body 6, and this is calculated by the vehicle body. Output to the electronic circuit, the electronic circuit calculates this rotation torque, the rotation angle of the steering, or various data from the speed sensor mounted on each part of the vehicle body, and various types of vehicles such as power steering devices and brake devices Control is performed.

  In other words, according to the running or stopping state of the vehicle, for example, when the vehicle is running and the rotational torque of the steering is small, the power steering device is loosened and the steering wheel is rotated with a heavy force to some extent, When the vehicle is stationary and the rotational torque of the steering is large, the power steering device is greatly utilized so that the steering wheel can be rotated even with a light force.

  At this time, as shown in FIG. 3, the magnet 22 is formed in a substantially arc shape having a width corresponding to a predetermined angle α with respect to the rotation center of the first rotating body 21, and the plurality of magnets 22 are rotated. A rotational torque detecting device with a small amount of magnet as a whole volume by fixing at a predetermined interval to the flange portion 21A of the rotating body 21 provided with a plurality of protrusions 21B having a width corresponding to a predetermined angle β with respect to the center. Thus, the apparatus can be formed at a low cost, and the rotational torque can be reliably detected.

  In other words, the plurality of magnets 22 are placed only on the portion of the first rotating body 21 necessary for detecting the rotational torque between the plurality of protrusions 5A and 6A of the first magnetic body 5 and the second magnetic body 6. By providing, the outer shape of the expensive magnet 22 is made small in a substantially arc shape, and the rotational torque detection device can be formed at low cost.

  In the above description, a plurality of protrusions 21B are provided in the vertical direction on the flange 21A at the lower end of the outer periphery of the rotating body 21 and six magnets 22 are fixed in the recess 21C therebetween. As shown in the partial perspective view of FIG. 5, if the protrusion 21D is formed also in the outer peripheral direction and the twelve magnets 22 are fixed in the recess 21C, the magnet 22 is further increased by the volume of the protrusion 21D. The amount of use can be reduced.

  In the above description, the magnet 22 is described as having a configuration with a width of, for example, an angle of 40 degrees with respect to the rotation center of the first rotating body 21, but as described above, it is necessary for detecting the rotational torque. Since the rotation angle of the magnet 22, the first magnetic body 5, and the second magnetic body 6 is actually about 4 degrees in the left-right direction, the angle of the magnet 22 with respect to the rotation center is 30 degrees or 20 degrees. Even with a configuration formed in a minute width, it is possible to reliably detect rotational torque.

  Further, the width of the magnet 22 is reduced in this way, and a large number of magnets 22 are fixed to the first rotating body 21 at predetermined intervals, and a plurality of protrusions of the first magnetic body 5 and the second magnetic body 6 are provided. By forming the parts 5A and 6A as many as eight or twelve, it is possible to detect rotational torque with higher accuracy.

  Further, although the present invention can be implemented even if there is only one magnetic detection element 9 disposed between the first magnetic body 5 and the second magnetic body 6, as described above, a plurality of magnetic detection elements 9 can be used. By detecting the magnetism of the magnet 22 with the detection element 9, even if one of the magnetic detection elements 9 is damaged or malfunctioned, the rotational torque can be detected and the control means 10 detects these. It is also possible to detect such breakage or failure by performing a magnetic comparison.

  As described above, according to the present embodiment, the magnets 22 are formed in a substantially arc shape, and the plurality of magnets 22 are fixed to the first rotating body 21 at predetermined intervals, and the magnetism detecting element 9 detects magnetism. By providing a plurality of substantially arc-shaped magnets 22 only at predetermined locations of the first rotating body 21 facing the first magnetic body 5 and the second magnetic body 6, a small amount of the entire volume can be obtained. Since the magnet can detect a delay in the rotation of the second rotating body 4 with respect to the first rotating body 21, it is possible to obtain a rotational torque detecting device capable of reliably detecting the rotational torque with an inexpensive configuration. is there.

  In the above description, the shape of a tongue piece formed by projecting the magnetism of the magnet 22 having the N pole and the S pole on the upper and lower surfaces to the inner circumference of the first magnetic body 5 and the second magnetic body 6 is provided. As described in the partial perspective view of FIG. 6 and the partial side view of FIG. 7, the N poles and S poles formed on the front and back surfaces are arranged in two rows. Using the adjacent magnet 22A, this magnetism is passed through a tongue-like projection 5B projecting on the outer peripheral lower surface of the first magnetic body 5 and a tongue-shaped projection 6B projecting on the outer peripheral upper surface of the second magnetic body 6. Therefore, the present invention can be implemented as a configuration that detects the above.

  That is, in FIG. 7A showing the state of the neutral position without rotating the steering wheel, the centers of the protrusions 5B and 6B are respectively at the centers of the N pole and the S pole of the magnet 22A. In this state, no magnetic flux is generated between the first magnetic body 5 and the second magnetic body 6, and the magnetism detected by the magnetic detection element 9 disposed between them is 0. It has become.

  Then, when the steering wheel is rotated to the right, for example, as shown in FIG. 7B, the first magnetic body 5 and the second magnetic body 6 start to rotate slightly behind the magnet 22A. Since the protrusion 5B has an N-pole and the protrusion 6B has an S-polarity, a magnetic flux is generated in the direction from the first magnetic body 5 to the second magnetic body 6, and this magnetism is detected by the magnetic detection element 9. Is configured to do.

  Further, as shown in the partial perspective view of FIG. 8 and the partial side view of FIG. 9, the magnet 22 </ b> B in which N poles and S poles formed on the front and back surfaces are formed adjacent to each other in three rows is used. If it is configured to detect the protrusion 5B on the lower surface of the outer periphery of one magnetic body 5 and the protrusion 6B on the upper surface of the outer periphery of the second magnetic body 6, the amount of magnets used can be further reduced.

  That is, when the number of the plurality of protrusions 5B and 6B is three, for example, as shown in FIG. 6, there are six magnets 22A adjacent to two rows of N poles and S poles as shown in FIG. Although twelve magnets are required, as shown in FIG. 8, the rotational torque can be detected with a small number of three magnets 22B adjacent to the three rows, that is, nine.

  The rotational torque detection device according to the present invention can be realized at a low cost and capable of reliably detecting rotational torque, and is mainly useful for detecting rotational torque of an automobile steering.

DESCRIPTION OF SYMBOLS 3 Holding body 4 2nd rotary body 5 1st magnetic body 5A, 5B, 6A, 6B Protrusion part 6 2nd magnetic body 7 Spacer 8 Wiring board 9 Magnetic detection element 10 Control means 11 Connection body 12 Upper case 13 Lower Case 21 First Rotating Body 21A Gutter 21B, 21D Protrusion 21C Recess 22, 22A, 22B Magnet

Claims (1)

A first rotating body that rotates in conjunction with the steering, a magnet fixed to the first rotating body, a second rotating body disposed below the first rotating body, and the second rotating body. First and second magnetic bodies fixed to the rotating body facing the magnet, a magnetic detecting element disposed between the first and second magnetic bodies, and an upper end of the first rotating body A rotating torque in which the lower end of the body is connected to the second rotating body, the magnet is formed in a substantially arc shape, and the plurality of magnets are fixed to the first rotating body at predetermined intervals. Detection device.

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