JP4453402B2 - Spiral cable device and variable transmission ratio unit using the same - Google Patents

Description

  The present invention relates to a spiral cable device having excellent vehicle mounting properties and high electrical reliability, and a variable transmission ratio unit using the spiral cable device.

  2. Description of the Related Art Conventionally, for example, there is a gear ratio variable power steering apparatus that includes a variable transmission ratio unit and that has a variable steering gear ratio by the action of the variable transmission ratio unit. The variable transmission ratio unit has a built-in drive motor that rotates integrally with the variable transmission ratio unit, and a rotation transmission ratio for transmitting rotational motion from the input shaft to the output shaft according to the rotation of the drive motor. Configured to change.

  In this variable transmission ratio unit, the drive current is supplied from an external device or the like toward the drive motor using, for example, a spiral cable device wound with a flexible flat cable (see, for example, Patent Document 1). And as said spiral cable apparatus, there exist some which shortened the dimension of the width direction and reduced in size, for example by winding a some flexible flat cable in multiple in a radial direction (for example, refer patent document 2). )

JP 2003-324836 A JP 2003-324835 A

  However, the conventional spiral cable device and the variable transmission ratio unit using the same have the following problems. That is, a spiral cable device in which a plurality of flexible flat cables in which a power line for passing a drive current that is a large current and a signal lead line for transmitting a weak signal are arranged in parallel as a lead wire are wound in a radial direction. Then, there is a possibility that the signal lead wire is located in the vicinity of the power line. Even if the power line and the signal lead wire are arranged in separate flexible flat cables, the power line and the signal lead wire may be positioned adjacent to each other in the radial direction. In such a case, electric noise or the like may be mixed from the power line to the signal lead line.

  In the variable transmission ratio unit configured using the conventional spiral cable device, for example, an electric signal is supplied from a power line that supplies a drive current to the drive motor to an output signal of a rotation angle sensor built in to detect a motor rotation angle. There is a risk of noise. Since the motor rotation angle is a control input value necessary for rotationally controlling the drive motor of the variable transmission ratio unit, the controllability of the variable transmission ratio unit may not be good unless the detection accuracy of the motor rotation angle is sufficient. There is.

  The present invention has been made in view of such conventional problems, and is an excellent spiral cable device that achieves both electrical reliability and vehicle mountability, and a variable with good controllability configured using the spiral cable device. It is intended to provide a transmission ratio unit.

According to a first aspect of the present invention, there is provided a cylindrical cover, a sleeve disposed on the inner peripheral side thereof in a state of being rotatable relative to the cover, a motor lead wire for supplying a driving current to at least the electric motor, and the above-described It has two flexible flat cables in which lead wires including signal lead wires for transmitting the output current of the rotation angle sensor for detecting the motor rotation angle of the electric motor are divided into two groups and arranged in parallel. A spiral in which one end of each flexible flat cable is fixed to the cover and the other end is fixed to the sleeve, and the two flexible flat cables are wound twice in the radial direction. In the cable device,
In the two flexible flat cables , the signal lead wire and the motor lead wire are respectively arranged, and in a state where one of the flexible flat cable and the other flexible cable are wound in a double manner, The signal lead wire arranged on one flexible cable and the signal lead wire arranged on the other flexible cable are arranged so as to be adjacent to each other in the radial direction, and arranged on one flexible cable. In the spiral cable device, the motor lead wire is arranged to be adjacent to a lead wire other than the motor lead wire or the signal lead wire arranged in the other flexible cable in a radial direction. Item 1).

In the spiral cable device according to the first invention, the two flexible flat cables in which the lead wires divided into two groups are arranged in parallel are wound twice in the radial direction.
In the spiral cable device, the two flexible flat cables are wound twice so that the signal lead wire is disposed so as to avoid a position adjacent to the motor lead wire in the radial direction.

As described above, in the spiral cable device according to the first aspect of the invention, the signal lead wire is arranged so as not to be adjacent to the motor lead wire in the radial direction.
Therefore, there is little possibility that electrical noise or the like that may be generated from the motor lead wire is mixed into the signal lead wire. In particular, when the flexible flat cables are wound and reduced in diameter due to relative rotation between the cover and the sleeve, and the radial gap between the two flexible flat cables is reduced, the motor lead wire is also used. There is little possibility that electrical noise or the like generated from the signal leads to the signal lead wire. Alternatively, due to the relative rotation of the cover and the sleeve, the flexible flat cables are wound and loosened to increase the diameter. For example, the flexible flat cables are pressed against the inner peripheral surface of the cover so that the two flexible flat cables are radially expanded. Even when approaching, there is little possibility that electrical noise or the like generated from the motor lead wire is mixed into the signal lead wire.

In particular, when electrical noise or the like is mixed into the signal lead wire having a smaller current value to be transmitted than the motor lead wire as described above, the current value or voltage value to be transmitted is likely to fluctuate due to the influence. Therefore, it is very effective to suppress the electric noise from being mixed into the signal lead wire by arranging the signal lead wire so as to avoid the position adjacent to the motor lead wire in the radial direction.

  As described above, in the spiral cable device according to the first aspect of the present invention, the two flexible flat cables are overlapped in the radial direction, thereby reducing the size in the parallel arrangement direction and improving the vehicle mountability. Further, when the two flexible flat cables are wound twice in the radial direction, the signal lead wires are arranged by avoiding positions adjacent to the motor lead wires in the radial direction, so that the signal lead wires are arranged. The electrical reliability is improved by suppressing the mixing of electrical noise and the like.

  In addition, as a method of grouping the lead wire group into two groups, not only a method of dividing the motor lead wire and the signal line into separate groups but also a plurality of the motor lead wires or the signal wires, for example. There is also a method of grouping such that the motor lead wires or the signal wires are included in both groups when there is a book.

A second invention is an electric motor that rotates integrally with an input shaft, a rotation angle sensor that detects a motor rotation angle of the electric motor, a motor lead wire that supplies a drive current to at least the electric motor, and the rotation angle sensor A spiral cable device in which two flexible flat cables, in which two lead wires including electrically connected sensor lead wires are grouped into two groups and arranged in parallel, are wound twice in the radial direction; In the variable transmission ratio unit configured to change the rotation transmission ratio when transmitting the rotational motion from the input shaft to the output shaft according to the rotation of the motor shaft of the electric motor,
As the sensor lead wire, there is at least a signal lead wire that transmits the output current of the rotation angle sensor,
The two flexible flat cables in the spiral cable device are respectively provided with the signal lead wire and the motor lead wire, and one flexible flat cable and the other flexible cable are wound in a double manner. In the rotated state, the signal lead wire arranged in one of the flexible cables and the signal lead wire arranged in the other flexible cable are arranged so as to be adjacent to each other in the radial direction, and one of the flexible cables The variable transmission characterized in that the motor lead wire arranged in the cable is arranged to be adjacent to the lead wire other than the motor lead wire or the signal lead wire arranged in the other flexible cable in the radial direction. In the ratio unit (claim 2).

In the variable transmission ratio unit according to the second aspect of the invention, the spiral cable device is formed by winding the two flexible flat cables twice in the radial direction.
Therefore, the spiral cable device can reduce the dimension in the parallel arrangement direction by reducing the width in the parallel arrangement direction of the flexible flat cables. Therefore, the variable transmission ratio unit provided with this spiral cable device is excellent in vehicle mountability.

In the spiral cable device, the two flexible flat cables are wound in the radial direction so that the signal lead wire and the motor lead wire are not adjacent to each other in the radial direction.
Therefore, there is little possibility that electrical noise or the like that may be generated from the motor lead wire is mixed into the signal lead wire.

As described above, in the variable transmission ratio unit according to the second aspect of the invention, the dimensions of the parallel arrangement direction are shortened by winding the two flexible flat cables twice in the radial direction. It is configured using the above spiral cable device that suppresses the possibility of electrical noise or the like mixed in the lead wire.
Therefore, the variable transmission ratio unit has excellent vehicle mountability and excellent characteristics that allow the motor rotation angle to be accurately measured by the rotation angle sensor.

  In addition, as a method of grouping the lead wire group into two groups, not only a method of dividing the motor lead wire and the signal line into separate groups but also a plurality of the motor lead wires or the signal wires, for example. There is also a method of grouping such that the motor lead wires or the signal wires are included in both groups when there is a book.

  In the first and second aspects of the invention, as an example of arranging the signal lead wire while avoiding a position adjacent to the motor lead wire in the radial direction, for example, the motor adjacent to the signal wire in the radial direction. A lead wire other than the lead wire is arranged, a lead wire that is not electrically used in the other flexible flat cable at a position adjacent to the signal wire in the radial direction, or a signal wire and the radial direction are arranged. In the other flexible flat cable, for example, a portion made only of the clothing material used for covering is arranged, or the other flexible flat cable is radially arranged at a position adjacent to the signal line in the radial direction. In order to prevent polymerization, the above two flexible flat cables are wound around.

In the second aspect of the invention, the electric motor is preferably a brushless motor.
In this case, the motor lead wire is required for each motor phase constituting the brushless motor, and the number of the motor lead wires is large, so that the second invention is particularly effective.

The variable transmission ratio unit is controlled via a plurality of lock lead wires, and has a lock mechanism configured to restrict or release the rotation of the electric motor. It is preferable that they are arranged on the same flexible flat cable of the two flexible flat cables or on different flexible flat cables.
In this case, the relative rotation between the input shaft and the output shaft connected via the variable transmission ratio unit can be restricted by the operation of the lock mechanism. Therefore, for example, when it is desired to directly connect the input shaft and the output shaft, the rotation transmission ratio by the variable transmission ratio unit can be fixed to 1 by the action of the lock mechanism.

The rotation angle sensor is a resolver, and as the sensor lead wires, the two signal lead wires, an excitation lead wire for applying an excitation voltage to the resolver, and a ground electrically connected to the ground side And having a line
The two signal lead wires are preferably arranged on different flexible flat cables, and are adjacent to the other signal lead wire in the radial direction (Claim 5).
In this case, in general, the motor rotation angle can be accurately detected using the resolver with high accuracy and high operation reliability. Since this resolver has a plurality of the signal lead wires, the effect of the second invention of suppressing the mixing of electric noise or the like into each signal lead wire is particularly effective.
Further, since the output current transmitted through the signal lead wires is particularly weak, the effect of the second invention is further effective.

Further, it is preferable that the signal lead wires are arranged at the end portions in the parallel arrangement direction of the flexible flat cables.
In this case, by arranging the signal lead wires at the end portions in the parallel arrangement direction of the flexible flat cables, it is possible to reduce electrical noise that may be mixed into the signal lead wires.

Each of the signal lead wires is preferably adjacent to the motor lead wire in the parallel arrangement direction with a lead wire other than the motor lead wire interposed therebetween.
In this case, by placing the motor lead wire and the signal lead wire in parallel across the lead wire other than the motor lead wire, electrical noise or the like that may be generated from the motor lead wire is generated. The possibility of mixing into the signal lead wire can be further suppressed.

Example 1
The variable transmission ratio unit 1 of this example will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the variable transmission ratio unit 1 of this example includes a brushless motor 11 that rotates integrally with an input shaft (in this example, the first steering shaft 321), and a motor rotation angle of the brushless motor 11. A group of lead wires including a resolver 18 for detecting the noise, motor lead wires 11a to 11c for supplying a drive current to at least the brushless motor 11, and sensor lead wires 18a to 18d electrically connected to the resolver 18 are grouped into two groups. And a spiral cable device 2 in which two flexible flat cables 21 and 22 arranged in parallel are wound twice in the radial direction.
The variable transmission ratio unit 1 transmits rotational motion from the first steering shaft 321 to the output shaft (in this example, the second steering shaft 322) in accordance with the rotation of the motor shaft 115 of the brushless motor 11. The rotation transmission ratio is changed.

Here, as the sensor lead wires 18a to 18d, there are signal lead wires 18a and 18c that transmit an output current of at least 0.1A of the resolver 18, and in the spiral cable device 2, each signal lead wire 18a, Two flexible flat cables 21 and 22 are wound so that c is arranged so as to avoid a position adjacent to the motor lead wires 11a to 11c in the radial direction.
This content will be described in detail below.

As shown in FIG. 4, the variable transmission ratio unit 1 of this example constitutes a gear ratio variable power steering apparatus 3 together with a steering gear box 35 incorporating a power cylinder (not shown).
In such a gear ratio variable power steering device 3, the variable transmission ratio is set so as to connect the first steering shaft 321 that rotates integrally with the steering handle 32 and the second steering shaft 322 that is fitted in the steering gear box 35. A unit 1 is provided.

  The steering gear box 35 of this example is of a rack and pinion type. As shown in the figure, in this steering gear box 35, a rack bar 351 is inserted and accommodated, and a second steering shaft 322 is inserted from a direction substantially orthogonal to the rack bar 351, and both are connected. The gear is engaged. That is, the steering gear box 35 is configured to convert the rotational motion of the second steering shaft 322 into linear motion in the axial direction of the rack bar 351.

  The gear ratio variable power steering device 3 of this example is based on a hydraulic power steering device in which a power cylinder using hydraulic pressure as a power source is incorporated in the steering gear box 35. Instead of the power cylinder, an electric actuator incorporating an electric motor can be incorporated to configure a variable gear ratio power steering device based on the electric power steering device.

  As shown in FIG. 3, the variable transmission ratio unit 1 includes a wave gear reducer 19, a brushless motor 11, and a spiral cable device 2. Then, by supplying a drive current using the spiral cable device 2 to rotate the brushless motor 11 and inputting the rotation operation to the wave gear reducer 19, the first steering shaft 321 to the second steering shaft 322 are rotated. The rotation transmission ratio at the time of transmitting the rotation operation to can be changed.

  As shown in the figure, the wave gear reducer 19 includes a pair of circular splines 191a and 191b having different numbers of teeth, a flex spline 193 meshing with the inner peripheral side of each of the circular splines 191a and 191b, and the flex spline 193. And a wave generator 192 fitted on the inner peripheral side.

  In the variable transmission ratio unit 1 of this example, as shown in FIGS. 3 and 5, the first steering shaft 321 is configured to rotate integrally with the circular spline 191 a via the housing 12. The second steering shaft 322 is configured to rotate integrally with the circular spline 191b. Further, the motor shaft 115 of the brushless motor 11 fixed inside the housing 12 that rotates integrally with the first steering shaft 321 is press-fitted into a cam 196 that constitutes the wave generator 192 via a driving key 195.

As shown in the figure, the variable transmission ratio unit 1 is configured to rotate the wave generator 192 by the rotation of the rotating shaft 115 of the brushless motor 11, thereby reducing the rotation and transmitting it to the circular spline 191b. ing.
In this example, the transmission ratio controller 60 (FIG. 9) described later is used to control the brushless motor 11 and adjust the rotation transmission ratio realized by the variable transmission ratio unit 1.

  Further, as shown in FIG. 3, the variable transmission ratio unit 1 has a resolver 18 adjacent to the brushless motor 11 for detecting the rotation angle of the rotor 111, that is, the motor rotation angle. The resolver 18 includes a rotor 181 that rotates integrally with the rotor 111, and a coil 182 that is fixed to the inner periphery of the housing 12 so as to be positioned on the outer periphery side of the rotor 181. The resolver 18 is configured to output an induced voltage of the coil 182 that changes according to the rotation of the rotor 181 toward the transmission ratio controller 60.

  The resolver 18 is electrically connected to the transmission ratio controller 60 via four sensor lead wires 18a to 18d (see FIGS. 1 and 2) arranged on the two flexible flat cables 21 and 22. It is. In this example, an excitation lead wire 18d that applies an excitation voltage to the resolver 18, a ground wire 18b that is electrically connected to the ground, and a first signal lead wire 18a that transmits the induced voltage of the resolver 18 as a sensor signal. There is a second signal lead 18c. Here, in the resolver 18 of this example, a sinusoidal induced voltage whose phase is shifted by 90 degrees is transmitted to the first signal lead wire 18a and the second signal lead wire 18c. In a transmission ratio controller 60 described later, the motor rotation angle is calculated by performing signal processing on two-phase induced voltages transmitted through the signal lead wires 18a and 18c.

Here, the change in the induced voltage transmitted to the first signal lead 18a and the second signal lead 18c is very weak and very small, and the current value is also very small. Therefore, the current value, voltage value, etc. transmitted to the signal lead wires 18a and 18c are likely to fluctuate due to the influence of electrical noise and the like. Therefore, the spiral cable device 2 of this example that can reduce the level of electrical noise and the like mixed in the signal lead wires 18a and 18c is effective.
As described above, in this example, the resolver 18 is used as the rotation angle sensor. However, instead of this, a rotation angle sensor using a Hall element may be used.

  Further, as shown in FIGS. 3 and 6, the variable transmission ratio unit 1 of this example includes a lock mechanism 15 that locks (restricts) or unlocks (restricts) the relative rotation between the rotor 111 and the stator 112. Have. In the lock mechanism 15, a lock lever 150 that rotates about the pin shaft 151 and a lock solenoid 155 that sucks the plunger 154 are disposed on the stator 112 side of the brushless motor 11. Further, a lock plate 157 is disposed on the rotor 111 side so as to rotate integrally with the rotor 111. The lock lever 150 has an action portion 153 that engages with the tip end portion of the plunger 154 and an engagement portion 152 that engages with the outer periphery of the lock plate 157 at both ends of the pin shaft 151. . Further, the lock plate 157 is formed with a concave portion 158 with which the engaging portion 152 is engaged on the outer peripheral portion thereof.

  In the lock mechanism 15, as shown in FIG. 6, a biasing force by a spring (not shown) acts on the lock lever 150 in the direction of arrow D. Therefore, when the lock solenoid 155 does not generate a suction force (when not operating), a clockwise rotational force (in the direction of arrow D in the figure) about the pin shaft 151 acts on the lock lever 150. To do. Therefore, the engaging portion 152 of the lock lever 150 is engaged with the recess 158 of the lock plate 157, and the relative rotation between the rotor 111 and the stator 112 (FIG. 3) is locked. When the rotation of the brushless motor 11 is locked, the first steering shaft 321 and the second steering shaft 322 are directly connected, and the rotation transmission ratio by the variable transmission ratio unit 1 becomes 1.

  On the other hand, when a suction force is generated in the lock solenoid 155 (during operation) and the plunger 154 is sucked, the lock lever 150 rotates counterclockwise (in the direction opposite to the arrow D in the figure) around the pin shaft 151. The engaging portion 152 is separated from the outer peripheral portion of the lock plate 157. Therefore, in the lock mechanism 15 of this example, when the lock solenoid 155 is operated, the rotor 111 and the stator 112 (FIG. 3) can be rotated relative to each other.

  As shown in FIG. 2, the lock mechanism 15 is electrically connected to the transmission ratio controller 60 via a pair of lock lead wires 15a and 15b. One of them is a lock lead wire 15a that is chopper-controlled between a battery voltage of 12V and a ground voltage of 0V and applies a time-variable chopper voltage, and the other one is a battery that is maintained substantially constant. The lock lead wire 15b applies a voltage of 12V.

As shown in FIG. 3, the variable transmission ratio unit 1 of the present example includes a cylindrical cover 25 fixed to the vehicle side and a first steering shaft 321 that is rotatable relative to the cover 25. A first flexible flat cable 21 having a sleeve 26 fixed to the outer peripheral side and wound twice in a radial direction in a gap formed between the cover 25 and the sleeve 26 and a second flexible cable. A spiral cable device 2 having a flat cable 22 is disposed.
In the spiral cable device 2, one end of each of the flexible flat cables 21 and 22 is fixed to the sleeve 26 and the other end is fixed to the cover 25.

In addition, the cover 25 of this example has the fixing | fixed part 251 for fixing to a vehicle on the outer peripheral side, and is fixing to the vehicle side via this fixing | fixed part 251.
Further, as shown in FIG. 3, the housing 12 of the variable transmission ratio unit 1 has a smaller diameter on the end side on the first steering shaft 321 side than the portion accommodating the brushless motor 11, and the first steering shaft 321. The fitting part 125 which fits is formed. In this example, the sleeve 26 is extrapolated and fixed to the fitting portion 125.

  As shown in FIG. 1, the first flexible flat cable 21 includes motor lead wires 11a and 11b connected to the U phase and V phase of the brushless motor 11, the excitation lead wire 18d of the sensor lead wires, and the first lead wire 18d. The signal lead wires 18a are arranged in parallel. Further, as shown in FIG. 2, the second flexible flat cable 22 includes a motor lead wire 11c connected to the W phase of the brushless motor 11, a ground wire 18b of the sensor lead wires, and a second signal lead wire 18c. The lock lead wires 15a and 15b connected to the lock mechanism 15 are arranged in parallel.

  Here, each of the motor lead wires 11a to 11c through which the drive current of the brushless motor 11 is passed is formed wider than the sensor lead wires 18a to 18d and the lock lead wires 15a and 15b. In this example, the cross-sectional shape of each of the sensor lead wires 18a to 11c and the lock lead wires 15a and 15b has a width w and a thickness t. The width 3w is approximately three times.

  As shown in FIG. 1, the first flexible flat cable 21 has a motor lead wire 11a, a motor lead wire 11b, an excitation lead wire 18d, and a first lead wire from the reference end portion 219 side which is one end portion in the parallel arrangement direction. The signal lead wires 18a are arranged in parallel in this order. And the 1st flexible flat cable 21 of this example insulation-coats each lead wire arranged in parallel by 1 layer with the flexible PET film 210. FIG.

  In the first flexible flat cable 21 of this example, as shown in the figure, the interval between the lead wires in the parallel arrangement direction is the same as the width of the sensor lead wires 18a to 18d and the lock lead wires 15a and 15b. w. Therefore, in the first flexible flat cable 21 of this example, the width of each of the motor lead wires 11a to 11c is equal to the parallel arrangement width of the two adjacent sensor lead wires 18a to 18d or the lock lead wires 15a and 15b. It almost agrees.

As shown in FIG. 2, the second flexible flat cable 22 has a reference end 229 (an end on the same side as the reference end of the first flexible flat cable 21) that is one end in the parallel arrangement direction. The motor lead wire 11c, the lock lead wires 15a, 15b, the ground wire 18b, and the second signal lead wire 18c are arranged in this order from the side. In the second flexible flat cable 22 of this example, each lead wire arranged in parallel in one layer is insulated and coated with a flexible PET film 220.
In the second flexible flat cable 22 of this example, the interval between the lead wires in the parallel arrangement direction is set to be the same w as the width of the sensor lead wire and the lock lead wire.

In this spiral cable device 2, as shown in FIG. 7, each flexible flat cable 21, 22 has one end fixed to the sleeve 26 via terminals 218, 228, and the other end. Is fixed to the cover 25 via terminals 219 and 229.
The motor lead wires 11a, 11b, the excitation lead wire 18d and the first signal lead wire 18a constituting the first flexible flat cable 21 are connected to the stator 112 of the brushless motor 11 via the terminal 218 on the sleeve 26 side. The rotation angle sensor is electrically connected to the transmission ratio controller 60 via a terminal 219 on the cover 25 side.

  The motor lead wire 11c, the ground wire 18b, the second signal lead wire 18c, and the pair of lock lead wires 15a and 15b constituting the second flexible flat cable 22 are connected to the brushless motor 11 via the terminal 228 on the sleeve 26 side. The stator 112, the rotation angle sensor 18 and the lock mechanism 15 are electrically connected to each other, and are electrically connected to the transmission ratio controller 60 via a terminal 229 on the cover 25 side.

  In the spiral cable device 2, as shown in FIG. 8, the first flexible flat cable 21 is arranged so that the positions of the reference end portions 219 and 229 of the flexible flat cables 21 and 22 in the parallel arrangement direction substantially coincide. And the second flexible flat cable 22 are overlapped in the radial direction and wound.

Therefore, in the spiral cable device 2 of this example, the U-phase motor lead wire 11a and the W-phase motor lead wire 11c are adjacent to each other in the radial direction, and the V-phase motor lead wire 11b is a set of two lock leads. Adjacent to the wires 15a and 15b in the radial direction.
In addition, the combination of the excitation lead wire 18d and the first signal lead wire 18a adjacent to each other in the first flexible flat cable 21 is the same as that of the ground wire 18b and the second signal lead wire 18c adjacent to each other in the second flexible flat cable 22. The combinations are arranged adjacent to each other in the radial direction.

And in the spiral cable apparatus 2 assembled | attached to the variable transmission ratio unit 1, if a driver | operator operates the steering handle 32 (FIG. 4), the 1st steering shaft 321 will rotate integrally and the housing 12 will rotate in connection with it. When the housing 12 rotates, relative rotation occurs between the sleeve 26 that rotates integrally with the housing 12 and the cover 25 that is fixed to the vehicle body.
When the sleeve 26 is rotated counterclockwise relative to the cover 25, the flexible flat cables 21 and 22 wound around the outer periphery of the sleeve 26 are wound up. On the other hand, when the sleeve 26 rotates to the right relative to the cover 25, the flexible flat cables 21, 22 wound around the outer periphery of the sleeve 26 are wound up.

  In the spiral cable device 2 of the present example, the angle range in which the sleeve 26 and the cover 25 rotate relative to each other is set to the winding range of the flexible flat cables 21 and 22. Therefore, as described above, even when relative rotation occurs between the sleeve 26 and the cover 25, electrical connection between the transmission ratio controller 60, the brushless motor 11, the rotation angle sensor 18, and the lock mechanism 15 is ensured. it can.

Next, the transmission ratio controller 60 that controls the variable transmission ratio unit 1 of this example will be described.
As shown in FIG. 9, the transmission ratio controller 60 is an input as an interface with a CPU 61 that performs various calculations, a ROM 62 that stores calculation programs, a RAM 63 that functions as a calculation area, and an external sensor. The interface unit 64 includes a drive circuit 65 that generates a drive current to be supplied to each motor phase of the brushless motor 11.

  The transmission ratio control controller 60 includes a vehicle speed sensor 601 that detects a vehicle speed value, a steering angle sensor 602 that detects a steering angle of the steering handle 32 (see FIG. 4), and a variable transmission ratio via the input interface unit 64. The rotation angle sensor 18 (see FIG. 3) built in the unit 1 is electrically connected. Here, as described above, the rotation angle sensor 18 is electrically connected to the transmission ratio controller 60 via the excitation lead wire 18d, the first and second signal lead wires 18a and 18c, and the ground wire 18b. is there.

The transmission ratio controller 60 captures the vehicle speed value and the steering angle, captures two sensor signals transmitted via the first and second signal leads 18a and 18c, and outputs the two sensor signals as signals. By processing, the motor rotation angle which is the rotation angle of the brushless motor 11 is calculated.
Then, the transmission ratio controller 60 calculates a target motor rotation angle as a control target value based on the captured vehicle speed value and steering angle, and the motor rotation angle detected by the rotation angle sensor 18 is substantially equal to the target motor rotation angle. The brushless motor 11 is controlled so as to match. In this example, a drive current is supplied to each motor phase of the brushless motor 11 via each of the three motor lead wires 11a, 11b, and 11c connected to the external terminal 651 of the drive circuit 65, and the brushless motor 11 It is configured to control rotation.

As described above, in the spiral cable device 2 of the variable transmission ratio unit 1 of this example, the first flexible flat cable 21 and the second flexible flat cable 22 are wound twice in the radial direction. is there.
Therefore, in the spiral cable device 2, the dimension in the parallel arrangement direction (axial direction) can be shortened, and the variable transmission ratio unit 1 provided with the spiral cable device 2 has excellent vehicle mountability.

  In the first flexible flat cable 21, the excitation lead wire 18 d is disposed between the motor lead wire 11 b and the first signal lead wire 18 a, so that the first flexible flat cable 21 is arranged at the end away from the motor lead wire 11 b. A signal line 18a is arranged. Further, in the second flexible flat cable 22, the motor lead wire 11c is disposed at the end on the reference end portion 229 side, and a pair of lock lead wires 15a, between the motor lead wire 11c, b and the ground wire 18b are arranged, and the second signal lead wire 18c is arranged at the opposite end.

  That is, in the spiral cable device 2 of the present example, the first signal lead wire 18a of the first flexible flat cable 21 and the second signal lead wire 18c of the second flexible flat cable 22 are both flexible. The flat cables 21 and 22 are disposed at the ends opposite to the reference ends 219 and 229. Further, the first signal line 18a and the second signal line 18c are arranged adjacent to each other in the radial direction.

As described above, in each of the flexible flat cables 21 and 22, the signal lead wires 18a and 18c are arranged at the end portions in the parallel arrangement direction. Further, each of the signal lead wires 18a and 18c is adjacent to the motor lead wires 11a to 11c in the parallel arrangement direction with a lead wire other than at least one motor lead wire 11a to 11c interposed therebetween.
Here, the magnetic field strength of the magnetic field that may be generated around the motor lead wires 11a to 11c is inversely proportional to the square of the distance. Therefore, in each of the flexible flat cables 21 and 22 in which the signal lead wires 18a and c and the motor lead wires 11a to 11c are arranged apart from each other, the signal lead wires 18a and c are arranged in parallel with the signal lead wires. There is little possibility that electrical noise is mixed from the motor lead wires 11a to 11c.

Furthermore, in the spiral cable device 2, when the first flexible flat cable 21 and the second flexible flat cable 22 are overlapped in the radial direction and wound, the signal lead wires 18a and 18c are adjacent to each other in the radial direction. It fits. That is, by arranging the signal lead wires 18a and 18c so as not to be adjacent to the power wires such as the motor lead wires 11a to 11c in the radial direction, the motor lead wires 11a to 11c and the like are changed to the signal lead wires 18a and 18c. The risk of electrical noise and the like being mixed can be reduced.
Therefore, the variable transmission ratio unit 1 including the spiral cable device 2 can accurately output a detection signal from the built-in rotation angle sensor 18. If the brushless motor 11 is controlled based on this accurate detection signal, the variable transmission ratio unit 1 can be controlled with high accuracy.

  As described above, the variable transmission ratio unit 1 of this example is excellent in vehicle mountability having the miniaturized spiral cable device 2. In addition, the spiral cable device 2 has high electrical reliability and excellent quality that can accurately output a detection signal from the rotation angle sensor 18 of the variable transmission ratio unit 1.

In the present example, the first flexible flat cable 21 and the second flexible flat cable 22 are configured independently. Instead, as in Reference Example 1 shown in FIGS. The lead wires are arranged so as to have a two-layer structure as if the flexible flat cables are overlapped, and are insulated and covered with a flexible PET film 230 while ensuring mutual electrical insulation. Can also be configured.

( Reference Example 2 )
In this example, the configuration of each flexible flat cable is changed based on the first embodiment. The contents will be described with reference to FIGS.
As shown in FIG. 12, the first flexible flat cable 21 of this example includes three motor lead wires 11a to 11c, one lock lead wire 15a, an excitation lead wire 18d, and a first signal lead wire 18a. They are arranged in parallel in order. Here, each of the motor lead wires 11a to 11c of this example has a similar shape to the sensor lead wires 18a to 18d and the lock lead wires 15a and 15b (width w and thickness t), and has a large width w1 and thickness. It has a cross-sectional shape of t1.

  When the three motor lead wires 11a to 11c, one lock lead wire 15a, the excitation lead wire 18d, and the first signal lead wire 18a are arranged in parallel, the side surface on one side of each lead wire is in the same plane. The PET film 210 is covered in the arranged state. Therefore, in the first flexible flat cable 21 of this example, a recess 228 is formed in a portion where the lock lead wire 15a and the sensor lead wires 18d and 18a formed thinner than the motor lead wires 11a to 11c are arranged.

  As shown in FIG. 13, the second flexible flat cable 22 has one lock lead wire 15d, a ground wire 18b, and a second signal lead wire 18c arranged in parallel. The number of lead wires arranged in the second flexible flat cable 22 of this example matches the number of lead wires other than the motor lead wires 11 a to 11 c in the first flexible flat cable 21. Therefore, the width of the second flexible flat cable 22 in the parallel arrangement direction substantially coincides with the formation width of the recess 218 (FIG. 12) of the first flexible flat cable 21.

Therefore, in the spiral cable device 2 of the present example, as shown in FIG. 14, the second flexible flat cable 22 is superposed in the radial direction with good placement efficiency by effectively utilizing the recesses 218 of the first flexible flat cable 21. Can be arranged.
Other configurations and operational effects are the same as those in the first embodiment.

  In this example, the first flexible flat cable 21 and the second flexible flat cable 22 are configured independently. Instead, as shown in FIG. 15, the two flexible flat cables are overlapped. Thus, the flexible flat cable 23 can be configured by arranging each lead wire so as to have a two-layer structure and insulatingly covering with a flexible PET film 230 while ensuring mutual electrical insulation.

Sectional drawing which shows the cross-section of the 1st flexible flat cable in Example 1. FIG. Sectional drawing which shows the cross-section of the 2nd flexible flat cable in Example 1. FIG. Sectional drawing which shows the cross-section of the variable transmission ratio unit in Example 1. FIG. Explanatory drawing explaining the gear ratio variable power steering apparatus in Example 1. FIG. Sectional drawing which shows the structure of the wave gear reducer in Example 1 (AA arrow sectional drawing in FIG. 3). Explanatory drawing explaining the locking mechanism in Example 1 (BB sectional view taken on the line in FIG. 3). Sectional drawing which shows the cross-section of the spiral cable apparatus in Example 1 (CC sectional view taken on the line CC in FIG. 3). Explanatory drawing explaining the adjacency relationship of the 1st flexible flat cable and 2nd flexible flat cable which were wound in multiple in the radial direction in Example 1. FIG. FIG. 2 is a block diagram illustrating a configuration of a transmission ratio control controller according to the first embodiment. Sectional drawing which shows the cross-section of the flexible flat cable in the reference example 1. FIG. In Reference Example 1, cross-sectional view showing the sectional structure of the spiral cable device which accommodates by winding a flexible flat cable shown in FIG. 10. Sectional drawing which shows the cross-section of the 1st flexible flat cable in the reference example 2. FIG. Sectional drawing which shows the cross-section of the 2nd flexible flat cable in the reference example 2. FIG. Explanatory drawing explaining the adjacency relationship of the 1st flexible flat cable and the 2nd flexible flat cable which were wound in multiples in the radial direction in the reference example 2. FIG. Sectional drawing which shows the cross-section of the other flexible flat cable in the reference example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Variable transmission ratio unit 11 Brushless motor 11a, 11b, 11c Motor lead wire 111 Rotor 112 Stator 15 Lock mechanism 15a, 15b Lock lead wire 18 Resolver 18a-d Sensor lead wire 18a, 18c Signal lead wire 18b Ground wire 18d Excitation lead wire 19 Wave Gear Reducer 2 Spiral Cable Device 21, 22, 23 Flexible Flat Cable

Claims (7)

A cylindrical cover, a sleeve disposed on the inner circumferential side of the cover so as to be rotatable relative to the cover, a motor lead wire for supplying a drive current to at least the electric motor, and a motor rotation angle of the electric motor Each of the flexible flat cables includes a group of lead wires including signal lead wires for transmitting an output current of a rotation angle sensor that detects the rotation and grouped into two groups and arranged in parallel. In the spiral cable device in which the two flexible flat cables are wound twice in the radial direction in a state where one end portion of the two is fixed to the cover and the other end portion is fixed to the sleeve,
In the two flexible flat cables , the signal lead wire and the motor lead wire are respectively arranged, and in a state where one of the flexible flat cable and the other flexible cable are wound in a double manner, The signal lead wire arranged on one flexible cable and the signal lead wire arranged on the other flexible cable are arranged so as to be adjacent to each other in the radial direction, and arranged on one flexible cable. The spiral cable apparatus according to claim 1, wherein the motor lead wire is arranged so as to be radially adjacent to a lead wire other than the motor lead wire or the signal lead wire arranged on the other flexible cable . An electric motor that rotates integrally with the input shaft, a rotation angle sensor that detects a motor rotation angle of the electric motor, a motor lead wire that supplies a drive current to at least the electric motor, and a sensor that is electrically connected to the rotation angle sensor A spiral cable device in which two flexible flat cables in which lead wires including lead wires are grouped into two groups and arranged in parallel are wound twice in the radial direction. In the variable transmission ratio unit configured to change the rotation transmission ratio when transmitting rotational motion from the input shaft to the output shaft according to the rotation of the shaft,
As the sensor lead wire, there is at least a signal lead wire that transmits the output current of the rotation angle sensor,
The two flexible flat cables in the spiral cable device are respectively provided with the signal lead wire and the motor lead wire, and one flexible flat cable and the other flexible cable are wound in a double manner. In the rotated state, the signal lead wire arranged in one of the flexible cables and the signal lead wire arranged in the other flexible cable are arranged so as to be adjacent to each other in the radial direction, and one of the flexible cables The variable transmission characterized in that the motor lead wire arranged in the cable is arranged to be adjacent to the lead wire other than the motor lead wire or the signal lead wire arranged in the other flexible cable in the radial direction. Ratio unit.   3. The variable transmission ratio unit according to claim 2, wherein the electric motor is a brushless motor.   The variable transmission ratio unit according to claim 2 or 3, wherein the variable transmission ratio unit is controlled via a plurality of lock lead wires, and includes a lock mechanism configured to restrict or release the rotation of the electric motor. The variable lead ratio unit, wherein the lock lead wire is disposed on the same flexible flat cable of the two flexible flat cables or different flexible flat cables. The rotation angle sensor according to any one of claims 2 to 4, wherein the rotation angle sensor is a resolver, and as the sensor lead wires, the two signal lead wires, an excitation lead wire for applying an excitation voltage to the resolver, A ground wire electrically connected to the ground side,
The variable transmission ratio unit, wherein the two signal lead wires are respectively arranged on different flexible flat cables and are adjacent to the other signal lead wire in the radial direction.   6. The variable transmission ratio unit according to claim 5, wherein each of the signal lead wires is disposed at an end portion of each of the flexible flat cables in the parallel arrangement direction.   7. The variable transmission ratio unit according to claim 5, wherein each of the signal lead wires is adjacent to the motor lead wire in a parallel arrangement direction with a lead wire other than the motor lead wire interposed therebetween.

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