JP4832976B2 - Electric cable drive device and electric parking brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric cable drive device enabling the tensions of left and right inner cables to be uniformized and having high durability. <P>SOLUTION: This cable drive device 10 comprises a motor M, a speed reducer G1 connected to the output shaft of the motor M, a rotating shaft 12 connected to the output side of the speed reducer G1 and having a profile section with a deformed cross section, an input gear 29 so installed on the rotating shaft 12 as to be moved in the axial direction, a screw shaft 35 having an output gear 30 meshed with the input gear 29 and so installed as to be moved in the axial direction, a nut member 34 screwed with the screw shaft 35 and so guided as to be moved in the axial direction and that its rotation is restrained, and a first inner cable 15 and a second inner cable 16 connected to the screw shaft 35 and the nut member 34, respectively. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to an electric cable drive device and an electric parking brake of an automobile using the same. Automobiles include various vehicles such as motorbikes, tricycles, power-assisted bicycles, golf carts, and forklifts.

JP-T-2001-513179

  Patent Document 1 discloses a vehicle parking brake 100 as shown in FIG. The parking brake 100 includes a gear member 101 formed on the outer periphery, a spline hub formed on the inner periphery, a component member 102 that is rotatably supported so as not to move in the axial direction, and the component member A hollow spline 103 that meshes with an inner peripheral spline hub and is movable in the axial direction, and a male screw member (spindle) 104 that engages with a female screw formed on the inner periphery of the spline.

  A first brake cable 105 is locked to one end of the spline 103, and a second brake cable 106 is locked to one end of the male screw member 104. The gear 101 on the outer periphery of the component member 102 is driven by the motor M, and when the motor rotates in one direction, the female screw of the spline 103 and the male screw member 104 are relatively screwed and the left and right brake cables 105 and 106 are rotated. They attract each other. As a result, the left and right brakes are applied.

  On the other hand, when the motor M rotates in the reverse direction, the female screw of the spline 103 and the male screw member 104 rotate relatively in the reverse direction to weaken the tension that the left and right brake cables 105, 106 attract. As a result, the brake is released. Since the telescopic device including the spline 103 and the male screw member 104 is axially movable with respect to the component member 102, the same force is applied to the left and right brakes. Thus, the parking brake of patent document 1 can apply | hang | release a parking brake with a motor, can be cancelled | released, and can equalize the brake force of right and left.

  Since the parking brake 100 of Patent Document 1 has a configuration in which the left and right brake cables 105 and 106 are pulled together, the tension between them can be equalized, and the space can be reduced. However, since the cable is connected to the spline 103 having the female screw, that is, the spline is provided at the final output portion of the reduction gear, the torque to be transmitted from the spline hub to the spline is large. Therefore, high processing accuracy is required for the spline hub and spline, and durability becomes a problem. In addition, since the transmission torque is large, the resistance of the sliding portion of the spline also increases, and the propulsive force efficiency is low.

  It is an object of the present invention to provide an electric cable driving device and an electric parking brake that have a simple mechanism and can make the left and right braking forces substantially equal when used in an electric parking brake. Furthermore, the present invention provides a highly durable electric cable drive device and electric parking brake that do not have a torque transmission portion that is movable in the axial direction, or that requires a small amount of torque to be transmitted even when there is a torque transmission portion. Providing is a second technical problem.

An electric cable driving device according to the present invention (Claim 1) includes a motor, a speed reducer coupled to the output shaft of the motor,
A rotating shaft connected to the output side of the speed reducer and having a contour section having an irregular cross section, an input gear supported on the rotating shaft so as to be axially movable and capable of transmitting torque, and meshed with the input gear A first screw member that is provided with an output gear and is axially movable together with the input gear , and a guide that is screwed to the first screw member, is axially movable, and is constrained to rotate. A second screw member, a first inner cable that is concentrically connected to the first screw member and extends in the axial direction, and one end connected to the second screw member. And a second inner cable extending to the opposite side.

  In such an electric cable drive device, it is preferable that the first screw is a nut member and the second screw is a screw shaft. In this case, an input gear is supported on the rotary shaft so as to be axially movable and capable of transmitting torque, and an output gear that meshes with the input gear is provided on the nut member, and the input gear and the output gear are provided. Are preferably provided with a gear box for supporting them so as to move together in the axial direction (claim 3).

According to a second aspect of the electric cable drive device of the present invention (Claim 4), a motor, a speed reducer connected to the output shaft of the motor, and an output member of the speed reducer are axially movable. The screw shaft is connected so as to be able to transmit torque, and has a contour section with a deformed cross section, and is screwed into the male screw of the screw shaft, and is guided so as to be freely movable in the axial direction and restricted in rotation. A nut member, a first inner cable that is concentrically rotatable with respect to the screw shaft and extends in the axial direction, and a second end that is connected to the nut member and extends to the opposite side of the first inner cable. and a inner cable relative to its housing, is characterized in that said motor and reduction gear is provided slidably in a direction extending the inner cable That.

According to a third aspect of the electric cable drive device of the present invention (Claim 5 ), a motor, a reduction gear connected to the output shaft of the motor, and a first screw connected to the output side of the reduction gear. A member, a second screw member that is screwed to the first screw member, is axially movable, and is guided to be constrained to rotate, and concentrically with respect to the first screw member The motor and the speed reducer, comprising: a first inner cable rotatably connected, extending in the axial direction; a second inner cable having one end connected to the nut member and extending to the opposite side of the first inner cable; and a housing. Is supported slidably in the direction in which the inner cable extends with respect to the housing.

Wherein in any of the electric cable drive device, which load detection device for detecting the tension of the first inner cable or the second inner cable is provided preferably (claim 6). The load detecting device includes a spring that is interposed between the first screw member and the first inner cable, or between the second screw member and the second inner cable, and that biases the inner cable in a pulling direction, and an inner cable. And a position sensor for detecting the position of ( 5 ).

Further, in any of the electric cable driving devices, a pulse generating means for generating a pulse in accordance with the rotation of the motor, and a means for counting an output pulse of the pulse generating means and converting it to an operation amount of the inner cable; It is preferable to have ( 6 ).

An electric parking brake for an automobile or the like of the present invention (Claim 9 ) includes any one of the cable driving devices, a wheel brake lever to which the other end of the first inner cable and the second inner cable are connected, and A spring for urging the brake lever toward the brake release side, and a brake friction member connected to the brake lever.

  In the cable drive device of the present invention (Claim 1), when the motor rotates in one direction, the speed reducer rotates and the rotating shaft connected to the output side of the speed reducer rotates. As a result, the first screw member provided to transmit torque with the rotating shaft rotates. As the first screw member rotates, the second screw member whose rotation is restricted is driven in the axial direction with respect to the first screw member because the screw engagement with the first screw member advances or retracts. The Accordingly, the first inner cable connected to the first screw member and the second inner cable connected to the second screw member are pulled into the inner side of the cable driving device, for example, to apply a brake.

  At this time, the first inner cable and the second inner cable are connected in series in the axial direction. In addition, since the first screw member is axially movable with respect to the rotating shaft, the first screw member can be connected to the first inner cable and the second inner cable even when the tension of the first inner cable is different from the tension of the second inner cable. It moves until the tension of the cable becomes equal, and the pulling force of both is almost equal.

  When the motor rotates in the other direction, the rotary shaft rotates in the opposite direction to that described above, and the first screw member and the second screw member move relative to each other in the axial direction in the opposite direction. Thereby, the force pulling the first inner cable and the second inner cable is weakened. Also in this case, the first screw member moves in the axial direction so that the tensions of the first inner cable and the second inner cable are substantially equal.

  When the first screw is a nut member and the second screw is a screw shaft (Claim 2), torque can be transmitted from the rotary shaft to the surface of the nut member. Easy to communicate.

  An input gear is supported on the rotary shaft so as to be axially movable and capable of transmitting torque, and an output gear that meshes with the input gear is provided on the nut member, and the input gear and the output gear are In the case where a gear box is provided for supporting the nut members to move together in the axial direction (Claim 3), the stroke of the nut member in the axial direction can be increased, and the gears of the input gear and the output gear can be increased. By appropriately selecting the ratio, it is possible to reduce the speed at that portion.

In the second aspect (Claim 4) of the cable drive device of the present invention, as in the cable drive device described above, when the motor rotates in one direction, the screw shaft rotates, and the first inner cable and the second inner cable. Operate to pull in. When the motor rotates in the reverse direction, the screw shaft rotates in the reverse direction, and the nut member moves away from the screw shaft. Thereby, both inner cables are separated from each other so as to reduce the tension. Since the screw shaft is connected to the output member of the speed reducer so as to be axially movable, the screw shaft moves so that the tensions of the first inner cable and the second inner cable are equal. In addition, since the motor and the speed reducer are slidably provided in the direction in which the inner cable extends, the slide between the first screw shaft and the output member of the speed reducer is provided. In addition to the stroke, an axial slide stroke is added to the motor and reducer housing. Thereby, the whole slide stroke becomes long. In other words, since the required axial slide stroke can be allocated to both the first screw and the rotary member and the speed reducer stroke, the axial length of the cable drive device can be made compact. Can do.

In the third aspect (Claim 5 ) of the cable drive device of the present invention, when the motor rotates in one direction, the speed reducer rotates and the first screw member connected to the output side rotates. As the first screw member rotates, the second screw member whose rotation is restricted is driven in the axial direction with respect to the first screw member because the screw engagement with the first screw member advances or retracts. The Thereby, the 1st inner cable connected with the 1st screw member and the 2nd inner cable connected with the 2nd screw member are drawn in the inside of a cable drive, for example. At that time, since the motor and the speed reducer are slidable with respect to the base, the tensions of the first inner cable and the second inner cable become substantially equal.

  When the motor rotates in the other direction, the first screw member rotates in the opposite direction, and the screwing directions of the first screw member and the second screw member are opposite to those described above. Moves in the opposite direction. Thereby, the force pulling the first inner cable and the second inner cable is weakened. Even in this case, the tensions of the first inner cable and the second inner cable are substantially equal.

When a load detection device for detecting the tension of the first inner cable or the second inner cable is provided (Claim 6 ), when an excessive load is applied to the inner cable, a warning is immediately given to the driver by the warning means. Appropriate measures can be taken, such as recognizing that this is the case, or stopping the motor. Thereby, the safety of the operation target of the inner cable or the device itself can be ensured.

  Further, if the motor is stopped when the inner cable is sent out when no load is applied, if the inner cable is permanently stretched, no extra cable is sent out. Therefore, the inner cable is not easily slackened, and an extra pulling operation is not required when the inner cable is pulled next.

A spring that is interposed between the first screw member and the first inner cable or between the second screw member and the second inner cable; In the case of a position sensor that detects the position of the first load (claim 7 ), it is possible to configure a load detection device that uses the proportional relationship between the spring and the load regardless of the axial movement of the first screw. Therefore, the tension of the inner cable can be easily detected.

In the case where there is provided means for counting the output of the pulse generating means for generating a pulse in accordance with the rotation of the motor and converting it to the amount of operation of the inner cable (Claim 8 ), the amount of operation of the inner cable can be determined with high accuracy. Can be detected. Thereby, after rotating a motor, it can be stopped at an appropriate timing. Further, it can be used for various controls such as detecting that an abnormality has occurred in combination with the output of the tension detection device described above.

The electric parking brake of the present invention (Claim 9 ) uses the above-described cable drive device, and therefore does not require a high-precision spline or spline hub, has high durability, and has a braking force for the left and right wheels. Can be almost even.

Next, embodiments of the cable drive device and the electric parking brake of the present invention will be described with reference to the drawings. 1 is a partially sectional plan view showing an embodiment of the cable driving device of the present invention, FIG. 2 is a partially sectional plan view showing an operating state of the cable driving device of FIG. 1, and FIG. 3 is III-III in FIG. 4a and 4b are front views showing other embodiments of the torque transmitting portion in the cable drive device of FIG. 1, and FIG. 5 is a schematic plan view showing one embodiment of the electric parking brake of the present invention. 6 is a partial cross-sectional plan view showing another embodiment of the cable drive device of the present invention, FIG. 7 is a partial cross-sectional plan view showing an operation state of a modification of the cable drive device of FIG. 5, and FIG. partial cross-sectional plan view showing an example of a range of cable drive device of the invention, FIG. 9 is a part sectional plan view showing another example of a range of cable drive device of the present invention, FIG 10 is a cable drive 9 FIG. 11 a is a front view of the nut member in FIG. 9. Figure, Figure 11b is a front view showing another example of nuts member.

  A cable drive device 10 shown in FIG. 1 includes a housing 11 serving as a base, a motor M attached to the housing, a first reducer G1 housed in the housing 11 and decelerating the rotation of the motor M, and a first thereof. A second reducer G2 slidably provided on an output shaft 12 of the reducer G1 and a guide rod 13 attached to the housing 11, a screw-nut mechanism 14 connected to an output part of the second reducer G2, A first inner cable 15 and a second inner cable 16 that are reciprocally driven in opposite directions by the screw-nut mechanism 14 are provided. Reference numeral 17 denotes a load detection device that is interposed between the first inner cable 15 and the screw-nut mechanism 14 and detects the tension of the first inner cable 15.

  As shown in FIG. 3, the first reduction gear G1 includes a pinion 21 fixed to the output shaft of the motor M, a first gear 23 rotatably supported by a first rod 22 attached to the housing 11, and a housing. 11 and a second gear 25 that is rotatably supported by a second rod 24 attached to 11. The first gear 23 has a large-diameter gear 23a that meshes with the pinion 21, and a small-diameter gear 23b that rotates together with the large-diameter gear 23a. The second gear 25 includes a large-diameter gear 25a that meshes with the small-diameter gear 23b of the first gear 23, and an output shaft (rotary shaft) 12 having a modified cross section that rotates together with the large-diameter gear.

  The irregular cross-section here is a cross-sectional shape other than a circle, and the driven member can be provided on the outer periphery thereof so as to be able to transmit torque and move in the axial direction. As the output shaft 12 having a modified cross section, a spline shaft is preferable. However, an output shaft 12a having an oval or elliptical cross section can be used as shown in FIG. 4a, and various forms such as a rectangular output shaft 12b and a polygonal output shaft can be used as shown in FIG. 4b. it can. In this embodiment, the irregularly shaped output shaft 12 constitutes a part of the second gear 25 and is rotatably supported around the second rod 24 described above. The end of the output shaft 12, particularly both ends, may be rotatably supported. In that case, the second rod 24 is unnecessary and can be solid.

  The first reduction gear G1 configured as described above decelerates the rotation of the motor M in two stages via the pinion 21, the first gear 23, and the second gear 25, and the next reduction gear G2 is obtained. Tell.

  Returning to FIG. 1, the second reduction gear G2 is accommodated in the gear box 28 that is guided by the output shaft 12 and the guide rod 13 of the first reduction gear G1 so as to be axially movable. A small-diameter input gear 29 provided so as to be axially movable around the output shaft 12 and capable of transmitting torque, and a large-diameter output gear 30 housed in the gear box 28 and meshed with the input gear 29. . The gear box 28 does not need to directly support the input gear 29 and the output gear 30 and may have a function of sliding the input gear 29 and the output gear 30 together in the axial direction. An intermediate gear having a large-diameter gear 23a and a small-diameter gear 23b such as the first gear 23 of the first reduction gear G1 may be interposed between the input gear 29 and the output gear 30.

  In this embodiment, the gear box 28 rotatably holds the circular cross-section portions provided on both sides of the input gear 29 via bearings or bearing bushes 31, and the circular cross-section portions provided on both sides of the output 30 The input gear 29 and the output gear 30 are moved together in the axial direction by being held rotatably via the bearing bush 32. Even when the gear box 28 is in any position in the axial direction, when torque is transmitted from the input gear 29 to the output gear 30, a speed reduction action corresponding to the gear ratio is exhibited.

  The screw-nut mechanism 14 includes a cylindrical nut member 34 integrated with the output gear 30 of the second reduction gear G2, and a screw having a male screw that is screwed with a female screw formed on the nut member 34. A shaft 35. One end (right side in FIG. 1) of the nut member 34 is supported by the housing 11 via the gear box 28 so as to be rotatable and axially movable, but the other end (left side in FIG. 1) is near the housing 11. It is preferable to support it rotatably and axially.

  In this embodiment, a substantially U-shaped connection bracket 37 is relatively rotatably connected to the other end of the nut member 34 via a swivel joint 36, and the first inner cable 15 is connected to the connection bracket 37. One end is connected. That is, the cable end 38 fixed to one end of the first inner cable 15 is locked to the joint 40 by the pin 39, and the base portion 41 a of the sliding rod 41 is screwed to the joint 40. The purpose of the screw connection is to use the joint 40 and the sliding rod 41 and close the clearance (backlash) of the spring 42.

  The sliding rod 41 passes through the bottom portion 37a of the connecting bracket 37, and a spring 42 made of a compression coil spring is interposed between the large-diameter head portion 41b of the sliding rod 41 and the bottom portion 37a of the connecting bracket 37. ing. The spring 42 is disposed so as to surround the sliding rod 41. In the connecting bracket 37, a sensor 43 or a proximity switch for detecting the position of the head 41b of the sliding rod 41 is provided. The sensor is preferably a Hall IC sensor. However, it can also be a limit switch. The spring 42 whose length changes in accordance with the tension of the first inner cable 15, the sliding rod 41 whose position changes thereby, and the sensor 43 that detects the position of the sliding rod 41 include the load detection device 17 described above. It is composed.

  One end of the second inner cable 16 is connected to the end of the screw shaft 35. The screw shaft 35 is guided by a guide 44 so as not to rotate and to be movable in the axial direction. Such a guide can be provided in the housing 11. In the cable driving device 10, the first inner cable 15 and the second inner cable 16 are disposed concentrically. The inner cables 15 and 16 are concentric with the screw-nut mechanism 14 and are parallel to the rotating shaft of the motor M.

  The inner cables 15 and 16 have flexibility obtained by twisting metal strands, and an inner cable (inner cable) used for a pull control cable is employed. A synthetic resin coating may be provided on the outer periphery of the stranded wire obtained by twisting metal strands. As shown in FIG. 5, the portions of the inner cables 15, 16 protruding from the housing 11 are brake mechanisms 50 for the left and right wheels (usually the rear wheels) of the automobile by an outer casing (conduit) 45 of the control cable. , 50 and is locked.

  The left and right outer casings 45, 45 are each composed of an armor layer in which a metal wire having a square cross section is tightly wound and a synthetic resin coating provided on the outer periphery thereof. A tube-shaped liner made of synthetic resin may be provided on the inner surface.

  The end of the outer casing 45 is fixed to a conventionally known cylindrical casing cap 46 by caulking or the like, and is fixed to the housing 11 using a flange and a male screw provided on the casing cap 46.

  In the screw-nut mechanism 14 configured as described above, when the output gear 30 and the nut member 34 rotate, the rotation of the screw shaft 35 screwed with the nut member 34 is restricted by the guide. It rotates relative to the nut member 34 and moves in the axial direction. That is, in the case of a right-hand thread, when the nut member 34 rotates toward the front side (clockwise as viewed from the left side in FIG. 1), the screw shaft 35 is relatively moved so as to enter the nut member 34 as shown in FIG. Moving. As a result, the screw shaft 35 and the nut member 34 are deeply screwed together, and the entire length of the nut-screw mechanism 14 composed of both is shortened. Accordingly, the first inner cable 15 connected to the nut member 34 and the second inner cable 16 connected to the screw shaft 35 are drawn into the cable driving device 10 and a braking action is exhibited.

  Further, since the screw-nut mechanism 14 itself is not fixed to the housing 11 in the axial direction, if the reaction forces of the left and right parking brakes are not uniform, the screw-nut mechanism is made to make the reaction forces uniform. 14 moves axially together with the gear box 28. As a result, the reaction forces on the left and right sides are almost equal, and the braking effectiveness is also almost equal. Since the screw shaft 35 moves by one pitch (one lead) of the screw when the nut member 34 makes one rotation, this mechanism can also reduce the speed. Further, the screw-nut mechanism 14 is a useful component for the electric parking brake because it has a self-restraining property that does not rotate the motor side by the force from the brake side even when the motor M is stopped. .

  When the motor M rotates in the reverse direction, the nut member 34 rotates so as to come out of the screw shaft 35, and the entire length of the screw-nut mechanism 14 becomes longer. As a result, the force for pulling the first inner cable 15 and the second inner cable 16 is eliminated. As a result, the brake operation can be released.

  In the cable drive device 10 of FIGS. 1 and 2, the nut member 34 is on the rotating side, and is therefore the first screw member in the present invention. Since the screw shaft 35 is the non-rotating side, it is the second screw member in the present invention. It is also possible to provide an output gear 30 on the screw shaft 35 and rotatably support it by the gear box 28, and to support the nut member 34 so as not to rotate and to be movable in the axial direction. In that case, the screw shaft 35 is the first screw member, and the nut member is the second screw member.

  1 and 2, the input gear 29 is fitted to the outer periphery of the output shaft 12 so as to be axially movable, and the output gear 30 provided on the nut member 34 is engaged with the input gear 29. However, the output shaft 12 can be a spline shaft, and the output gear 30 can be directly meshed with the output shaft 12.

  For example, a DC brushless motor having a three-phase coil phase is used as the motor M. The magnetic poles of the coil phase are reversely excited between the rotor of the motor M and a fixed element such as the housing 11 facing the rotor, or between the rotating member such as the first gear 23 and the fixed element such as the housing 11. It is preferable to provide a position detecting sensor for detecting the operation stroke of the inner cables 15 and 16.

  As such a sensor, a combination of three detection magnets provided on the rotor and a Hall IC sensor (Hall effect element sensor) provided on the motor housing is suitable. Instead of the detection magnet, a driving magnet that acts on the coil may be used. The configuration is simpler. In addition to the three Hall IC sensors, other sensors such as an optical sensor can also be used. The outputs of these sensors are sent to a motor driver having an amplifier circuit such as a comparator and a commutation circuit for inverting the magnetic poles of the coils.

  In the cable drive device of the present invention, it is preferable that the pulse output of the cable position detection sensor is sent to a cable position calculation circuit, the number of pulses is counted, and converted into a signal indicating the cable position. The obtained cable position signal is basically sent to the microprocessor as a position signal to be operated by the cable, and the operation switch for ON / OFF operation of the brake and the motor M based on various interlock signals. Control signals for forward rotation, stop, reverse rotation, and rotation speed are generated, and the motor M is rotated / stopped via the motor driver.

  Also, changes in the cable reference position due to compensation for permanent elongation of the inner cable, wear of friction members for brakes, etc. are calculated and stored every time or several times of brake operation, and should be used for appropriate brake operation. Can do. When compensating for the permanent elongation of the inner cable, for example, when the load detection device 17 detects a no-load state in the operation of feeding the inner cable, the motor is stopped and the reference position of the cable position is reset to zero. It can be carried out.

  Next, an embodiment of an electric parking brake provided with the cable drive device will be described with reference to FIG. The electric parking brake 54 shown in FIG. 5 includes the cable drive device 10 described above, control cables 55 and 55 extending from the cable drive device 10 to the left and right, and a brake connected to the other end of the control cables 55 and 55. It consists of mechanisms 50 and 50. The brake mechanism 50 includes a brake drum, a brake shoe attached to the brake drum, a return spring that urges the brake drum in the return direction (arrow R direction), and parking that is operated by the inner cables 15 and 16 of the control cable 55. It is a well-known thing provided with the lever.

  In the normal state, the electric parking brake 54 is in a brake released state by rotating the brake drum in one direction by the urging force of the return spring. When the driver turns on the switch, the motor M of the cable driving device 10 rotates in one direction, the nut member 34 in FIG. 1 rotates, and the screw shaft 35 is pulled into the nut member 34. Thereby, the inner cables 15 and 16 connected to the nut member 34 and the screw shaft 35 are pulled, and the inner cables 15 and 16 of the control cable 55 in FIG. 5 are pulled. As a result, the parking lever is rotated in the brake operating direction to apply the brake.

  At the time of this braking action, a stop signal is issued in comparison with the data stored in advance by the cable operation position detection circuit, and the motor stops. Further, when the output of the load detection device 17 is sent to the control circuit and exceeds a predetermined upper limit value, the motor M is stopped. The cable operation amount detection circuit detects the position of the cable, and when the cable load exceeds a predetermined value even though the cable is not moved until the brake is applied, it is determined that the system is abnormal. In addition, the driver can be made aware of the failure with a warning lamp or warning buzzer.

  When the driver releases the brake, the motor M is rotated in the reverse direction by operating the switch, and the screw shaft 35 is sent out from the nut member 34. Thereby, the inner cables 15 and 16 are pulled back by the urging force of the return spring of the brake mechanism 50 of FIG. At the timing of stopping the motor M, it is necessary that the brake is sufficiently applied and that the inner cables 15 and 16 are not slackened.

  Therefore, in the control circuit, when the inner cables 15 and 16 are sent out, the motor M is stopped when no load is applied. Therefore, when the inner cables 15 and 16 are permanently stretched, the inner cables 15 and 16 are not sent out excessively. Accordingly, the inner cables 15 and 16 are not easily slackened, and an extra pulling operation is not necessary when the inner cables 15 and 16 are next pulled. Furthermore, since the control of the motor M of the cable driving device 10 is highly accurate as described above, the brake operation is performed appropriately, wasteful wear of the friction member is suppressed, and the slack and tension of the inner cables 15 and 16 are suppressed. Wear due to excess is suppressed.

  The electric parking brake 54 as described above is normally used during parking. However, it is preferable to be able to operate as an emergency brake to replace the service brake in an emergency. In the embodiment, a three-phase brushless motor is used as the motor M. However, a motor with a brush may be used, and an excitation type motor having three or more phases may be used.

  When using a motor that does not include pulse generation means such as a motor with a brush, it is preferable to provide means for generating pulses by rotation of the output shaft of the motor, the gear of a reduction gear, a nut member, or the like. . Such a pulse generating means includes a detection magnet (basically one multipolar magnet) provided on a rotating member such as a rotating shaft or gear, and a Hall IC sensor (Hall effect element sensor) provided on a fixed element such as a casing. ) Is preferred.

  Next, another embodiment of the cable driving apparatus of the present invention will be described with reference to FIGS. This cable drive device 60 is provided so as to be slidable in the direction in which the inner cables 15, 16 extend by two guide rods 61, 61 with the gear box 28 attached to the housing 11, and the motor M is mounted on the gear box 28. It is attached. Further, the second reduction gear (reference numeral G2 in FIG. 1) is omitted, the small gear 23b of the first gear 23 of the first reduction gear G1 is engaged with the output gear 30, and the screw shaft 35 is connected to the output gear 30. A part (slide part) 35a of this is connected so as to be able to transmit torque and slide in the axial direction. Thereby, the motor M is movable in the axial direction together with the first reduction gear G1, and the screw shaft 35 is movable in the axial direction with respect to the first reduction gear G1.

  The sliding portion of the screw shaft 35 can be a spline shaft, or can be oval or elliptical like the output shaft 12a of FIG. 4a. Moreover, it can also be made into a square shape or polygonal shape like the output shaft 12b of FIG. 4b. The output gear 30 is formed with a hole that fits the slide portion of the screw shaft 35 so as to be axially movable and capable of transmitting torque. Further, the output gear 30 is provided with a sensor 62 for detecting the operation position of the cable.

  A nut member 34 having a female screw that is screwed with a male screw of the screw shaft 35 is provided so as not to rotate with respect to the housing 11 and to be movable in the axial direction. In this case, the nut member 34 and the screw shaft 35 constitute the screw-nut mechanism 14. However, in this embodiment, the nut member 34 is on the non-rotating side, so it is a second screw member, and the screw shaft 35 is on the rotating side, so it is the first screw member. However, as in the case of FIGS. 1 and 2, the output gear 30 is provided on the nut member 34, and the screw shaft 35 is screwed onto the nut member 34 so that the screw shaft 35 is axially movable and does not rotate. You can also guide.

  In the cable drive device 60 of FIG. 6, the nut member 34 is shorter than that of FIG. 1, and is fixed to a cylindrical or U-shaped connection bracket 37 that accepts the entry of the screw shaft 35. The connecting bracket 37 may be guided so as not to rotate with respect to the housing 11 and to be movable in the axial direction.

  Similarly to the case described above, one end of the second inner cable 16 is locked to the connection bracket 37 via the load detection device 17. The first inner cable 15 is connected to the end of the screw shaft 35 via a swivel joint 63. The other structure is the same as that of the cable drive device 10 of FIG. 1, and there exists the same effect.

  Further, the cable drive device 60 is configured so that the entire motor M and the gear box 28 are slidable, so that torque can be transmitted in the middle of a torque transmission element such as a gear of a reduction gear, and in the axial direction. There is no need to provide a sliding mechanism such as a combination of a spline and a spline hub. Further, the cable drive device 60 employs both a configuration in which the gear box 28 is provided so as to be movable in the axial direction and a configuration in which the screw shaft 35 is provided so as to be able to transmit torque to the output gear 30 and be movable in the axial direction. Therefore, the axial length of the housing 11 can be shortened.

  However, a configuration in which the screw shaft 35 is provided so as to be axially movable with respect to the output gear 30 may be omitted so that the screw shaft 35 does not move relative to the output gear 30. In that case, the screw shaft 35 and the output gear 30 may be formed separately and fixed to each other, or may be molded integrally. The screw shaft 35 or the output gear 30 is supported by a bearing that supports a thrust load with respect to the gear box 28 so as to be rotatable and transmit axial force.

  Even in this case, since the gear box 28 is slidable in the axial direction of the inner cables 15, 16 by the guide rods 61, 61, it is possible to balance the tension between the first inner cable 15 and the second inner cable 16. it can. Further, the stroke for balancing the first inner cable 15 and the second inner cable 16 is shortened, but the overall configuration is simplified.

  Further, in the cable driving device 60 shown in FIG. 6, as shown in FIG. 7, a spring 64 that biases the gear box 28 toward the first inner cable 15 (right side in FIG. 7) may be provided. Such a spring 64 may be formed of a compression coil spring, interposed between the inner wall of the housing 11 and the gear box 28, and may be disposed around the guide rod 61, respectively. In the case where such a spring 64 is provided, the gear box 28 can be pressed in one direction, so that vibration can be suppressed and generation of looseness and abnormal noise can be suppressed.

Next, an example of a cable driving device outside the scope of the present invention will be described with reference to FIG. The cable driving device 70 shown in FIG. 8 has a configuration in which the screw shaft 35 in the cable driving device 60 in FIG. 6 can transmit torque to the output gear 30 and can move in the axial direction. The rod 61 is omitted, and the gear box 28 is fixed to the housing 11. That is, the movable structure of the gear box 28 in the cable driving device 60 of FIG. 6 is omitted.

  The screw shaft 35 is provided so as to be axially movable and capable of transmitting torque with respect to the output gear 30, the first inner cable 15 is connected to the screw shaft 35, and the second inner cable 16 is connected to the nut member 34. This is substantially the same as the cable driving device 60 of FIG. In this cable driving device 70, the stroke for balancing the first inner cable 15 and the second inner cable 16 is shorter than in the case of FIG. 6, but the overall configuration is simplified.

  In addition, in the cable drive device 70 of FIG. 8, the 1st guide member 71 which guides the connection bracket 37 holding the nut member 34 so that axial movement is possible and it does not rotate is provided. Further, a second guide member 72 is provided for guiding the swivel joint 63 so as to be movable in the axial direction and not to rotate. The first guide member 71 is for ensuring the advance and retreat based on the screwing of the male screw of the screw shaft 35 and the nut member 34 and for preventing the second inner cable 16 from being twisted. . The second guide member 72 is for preventing a twisting force from being applied to the first inner cable 15, and there is no possibility that the inner cable is untwisted. Although not shown, the same guide members 71 and 72 are also applied to the first inner cable 15 of the cable driving device 10 of FIG. 1 or the first inner cable 15 and the second inner cable 16 of the cable driving device 60 of FIG. Is preferably provided.

  The first inner cable 15 and the second inner cable 16 are slidably guided by the first outer casing 45a and the second outer casing 45b, respectively. End portions of the first outer casing 45a and the second outer casing 45b are fixed to the housing 11 by casing caps 46 and 46, respectively. Such guides of the first and second inner cables 15 and 16 by the first and second outer casings 45a and 45b are similarly adopted for the cable driving device 10 of FIG. 1 and the cable driving device 60 of FIG. Can do.

  The cable drive device 74 shown in FIG. 9 is fitted to the output gear 30 so as to be axially movable and transmit torque, contrary to the cable drive device 70 of FIG. 8, with the nut member 34 as the first screw member. I am letting. A screw shaft 35 that is a second screw member is screwed onto the nut member 34. Then, the first inner cable 15 is rotatably connected to the nut member 34 via the connecting member 37 so as not to transmit the rotation, the connecting member 37 is not rotated by the first guide member 71, and the shaft It is guided to move freely.

  On the other hand, the screw shaft 35 is provided with a slide portion 35b at an end thereof, and the slide portion 35b is guided by the second guide member 72 so as not to rotate and is movable in the axial direction.

  As shown in FIG. 10a, the outline of the nut member 34 has a substantially oval or oval shape. The output gear 30 is formed with an oval or oval hole that is fitted to the nut member 34 so as to be axially movable. Thereby, the nut member 34 is fitted to the output gear 30 so as to be able to transmit torque and move in the axial direction.

  Instead of the oval shape, a nut member 34 having a square or rectangular outline and an output gear 30 having a cavity of the shape as shown in FIG. 11b may be employed.

  In the above embodiment, the proportional relationship between the force and the length of the compression coil spring is used as the load detection device, but a tension coil spring can also be used. In addition, a commercially available strain gauge can be fixed to the plate. In such a load sensor, when a load is applied to the inner cable and the plate is elastically deformed, the electrical resistance of the strain gauge changes. The load can be detected by accurately measuring the change with a Wheatstone bridge or the like.

  In the embodiment, the load detection device 17 is provided only on the first inner cable 15. This is because the tension between the left and right inner cables 15 and 16 is balanced by the axial slide of the gear box 28 or the like, so that it is only necessary to detect the tension of one of the inner cables. In addition, the load detection mechanism 17 can also be interposed between the screw shaft 35 and the second inner cable 16 in FIG. Further, it may be interposed in the middle of the first inner cable 15 or in the middle of the second inner cable 16.

  In any case, the load detection device 17 can detect whether excessive tension is applied to the inner cables 15 and 16 when the parking brake is operated or whether slack has occurred. If excessive tension is detected during the braking operation, temporarily stop the motor M, and if excessive tension remains even after applying the brake for about 2 to 3 times, an abnormality has occurred. Turn on the indicator light or sound the buzzer to inform the driver. Further, the motor M may be stopped.

  In the cable driving device 60 of FIG. 6, the housing 11 is fixed to the vehicle body, and the gear box 28 is supported movably in the direction in which the inner cables 15 and 16 extend with respect to the housing 11. However, conversely, the gear box 28 can be fixed to the vehicle body, and the housing 11 can be arranged so as to be movable in the direction in which the inner cables 15 and 16 extend with respect to the vehicle body.

  In this case, for example, when the tension of the first inner cable 15 becomes larger than the tension of the second inner cable 16, the compressive force in the axial direction of the first outer casing 45a that guides the first inner cable 15 is the second inner cable 15. Since the compression force of the second outer casing 45b that guides the cable 16 is larger, the housing 11 is pushed and moved toward the second inner cable 16 side. When the tension of the second inner cable 16 becomes larger than the tension of the first inner cable 15, the housing 11 moves to the first inner cable 15 side contrary to the above. As a result, the compressive forces of both the outer casings 45a and 45b are balanced, and as a result, the tensions of the inner cables 15 and 16 are balanced.

It is a partial cross section top view which shows one Embodiment of the cable drive device of this invention. It is a partial cross section top view which shows the operation state of the cable drive device of FIG. It is the III-III sectional view taken on the line of FIG. 4a and 4b are front views showing other embodiments of the torque transmitting portion in the cable driving device of FIG. 1 is a schematic plan view showing an embodiment of an electric parking brake of the present invention. It is a partial cross section top view which shows one Embodiment of the cable drive device of this invention. It is a partial cross section top view which shows the operation state of the modification of the cable drive device of FIG. It is a partial cross section top view which shows an example of the cable drive device outside the scope of the present invention. It is a partial cross section top view which shows the other example of the cable drive device outside the range of this invention. It is a principal part perspective view of the cable drive device of FIG. Figure 11a is a front view of the nut member in FIG. 9, FIG. 11b is a front view showing another example of nuts member. It is a perspective view which shows an example of the conventional cable drive device.

Explanation of symbols

10 cable drive device 11 housing M motor G1 first reduction gear 12 output shaft
13 Guide rod G2 Second reduction gear 14 Screw-nut mechanism 15 First inner cable 16 Second inner cable 17 Load detection device 21 Pinion 22 First rod 23 First gear 23a Large diameter gear 23b Small diameter gear 24 Second rod 25 First 2 gear 25a large diameter gear 12a, 12b output shaft 28 gear box 29 input gear 30 output gear 31, 32 bearing bush 34 nut member
35 Screw shaft 36 Swivel joint 37 Connection bracket 37a Bottom 38 Cable end 39 Pin 40 Joint 41 Sliding rod 41a Base 41b Head 42 Spring 43 Sensor 44 Guide
45 outer casing 46 casing cap 50 brake mechanism 54 electric parking brake 55 control cable 60 cable driving device 61 guide rod 62 rotation sensor 63 swivel joint 64 spring 70 cable driving device 71 first guide member 72 second guide member 45a first outer Casing 45b Second outer casing 74 Cable drive device 35b Slide portion

Claims (9)

A motor,
A reduction gear connected to the output shaft of the motor;
A rotating shaft connected to the output side of the speed reducer and having a contour section with an irregular cross section;
An input gear supported on the rotating shaft so as to be axially movable and capable of transmitting torque; and an output gear meshing with the input gear; and a first screw member provided axially movable together with the input gear;
A second screw member that is screwed into the first screw member and guided so as to be axially movable and restricted in rotation;
A first inner cable that is concentrically rotatable with respect to the first screw member and extends in the axial direction;
An electric cable driving device comprising: a second inner cable having one end connected to the second screw member and extending to the opposite side of the first inner cable. The electric cable drive device according to claim 1, wherein the first screw is a nut member and the second screw is a screw shaft. And an output gear and the entering force gear, they electric cable drive device according to claim 2, characterized in that comprises a gear box which supports so as to move together in the axial direction. A motor,
A reduction gear connected to the output shaft of the motor;
A screw shaft that is connected to the output member of the speed reducer so as to be movable in the axial direction and capable of transmitting torque, and has a contour section having an irregular cross section,
A nut member that is screwed into the male screw of the screw shaft, guided in such a manner as to be axially movable and restricted in rotation,
A first inner cable that is concentrically rotatable with respect to the screw shaft and extends in the axial direction;
A second inner cable having one end connected to the nut member and extending to the opposite side of the first inner cable;
A housing ,
An electric cable driving device in which the motor and the speed reducer are slidably provided in the direction in which the inner cable extends with respect to the housing . A motor,
A reduction gear connected to the output shaft of the motor;
A first screw member coupled to the output side of the speed reducer;
A second screw member that is screwed into the first screw member and guided so as to be axially movable and restricted in rotation;
A first inner cable that is concentrically rotatable with respect to the first screw member and extends in the axial direction;
A second inner cable having one end connected to the nut member and extending to the opposite side of the first inner cable;
A housing,
An electric cable driving device in which the motor and the speed reducer are slidably supported in a direction in which an inner cable extends with respect to a housing. The electric cable drive device according to any one of claims 1 to 5 , further comprising a load detection device that detects a tension of the first inner cable or the second inner cable. A spring that is interposed between the first screw member and the first inner cable or between the second screw member and the second inner cable; The electric cable drive device according to claim 6, further comprising a position sensor for detecting the position of the motor. Pulse generating means for generating a pulse in response to rotation of the motor, to any one of claims 1 to 7, and means for converting the operation amount of the inner cable by counting the output pulses of the pulse generating means The cable drive device described. The cable drive device according to any one of claims 1 to 8 , a brake lever of a wheel to which the other ends of the first inner cable and the second inner cable are connected, and biasing those brake levers toward the brake release side An electric parking brake for an automobile or the like including a spring for driving and a brake friction member coupled to a brake lever.

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