Power door opening/closing apparatus

A power door opening/closing apparatus includes: a first unit including the motor, a first unit case including the motor, a first transmission mechanism received in the first unit case, and a rotation sensor which is received within the first unit case, and which is one of electrical components; and a second unit which includes a second unit case connected to the first unit case by a fixing member, a second transmission mechanism rotatably received within the second unit case, and connected to the first transmission mechanism, and an output shaft connected to an output side of the second transmission mechanism, and arranged to transmit a rotation of the second transmission mechanism to the door, and which does not include an electrical component.

BACKGROUND OF THE INVENTION

This invention relates to a power door opening/closing apparatus arranged to open and close a door by a power of a motor.

A door such as a back door and a sliding door of a vehicle can be electrically opened and closed by a power door opening/closing apparatus, in addition to a manual operation. The power door opening/closing apparatus includes a motor, an output portion arranged to output a power of the motor, and a transmission mechanism arranged to transmit the power of the motor to the output portion. The power door opening/closing apparatus is provided to a vehicle body, or a door provided to the vehicle body to be opened and closed. The power door opening/closing apparatus moves the door in the open direction or in the close direction by the power outputted from the output portion.

For example, a patent document 1 (Japanese Patent Application Publication No. 2005-082019) discloses a power door opening/closing apparatus including electrical components such as an electromagnetic clutch arranged to switch a connection state in which a rotation of a motor can be transmitted to an output portion, and a disconnection state in which the rotation of the motor cannot be transmitted to the output portion, and a rotation sensor (which is not described in the patent document 1) arranged to sense a rotation of a transmission mechanism. The electromagnetic clutch is controlled by a control section. When the door is manually opened and closed, the electromagnetic clutch is switched to the disconnection state. Moreover, when the door is electrically opened and closed, the electromagnetic clutch is switched to the connection state. Furthermore, the rotation sensor senses an open position and a close position of the door, and an open direction and a close direction of the door by sensing the rotation of the transmission mechanism.

SUMMARY OF THE INVENTION

However, in the above-described power door opening/closing apparatus, the motor is connected to a single case. Moreover, mechanism components (transmission mechanism) constituted by reduction gears, shafts and so on, and the electrical components such as the electromagnetic clutch and the rotation sensor are received within the case. Therefore, in the assembly operation or the inspection of the power door opening/closing apparatus, it is not possible to confirm the operation of the only the electrical component, and to confirm the operation of the only mechanism. Accordingly, the assembly operation of the apparatus is inefficient. This causes the decrease of the productivity.

It is, therefore, an object of the present invention to provide a power door opening/closing apparatus which is devised to solve the above mentioned problems, and to improve a productivity.

According to one aspect of the present invention, a power door opening/closing apparatus arranged to open and close a door by a power of a motor, the power door opening/closing apparatus comprises: a first unit including the motor, a first unit case including the motor, a first transmission mechanism received in the first unit case, and arranged to transmit a rotation of the motor, and a rotation sensor which is received within the first unit case, which is one of electrical components, and which is arranged to sense a rotation of the first transmission mechanism; and a second unit which includes a second unit case connected to the first unit case by a fixing member, a second transmission mechanism rotatably received within the second unit case, and connected to the first transmission mechanism, and an output shaft connected to an output side of the second transmission mechanism, and arranged to transmit a rotation of the second transmission mechanism to the door, and which does not include an electrical component.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, one embodiment of the present invention is illustrated.FIG. 1is a perspective view showing a vehicle as viewed from a diagonally rearward direction of the vehicle. A numeral1is a vehicle body. A numeral2is a back door which is supported to be opened and closed in upward and downward directions by left and right door hinges3that are provided at rear upper portions of the vehicle body1. The back door2is pivotally supported by the door hinges3to be opened and closed. With this, the back door2is arranged to be moved between a close position (a position shown by a solid line inFIG. 1) at which the back door2closes a rear opening of the vehicle body1, and an open position (a position shown by a two dot chain line inFIG. 1) at which the rear end portion of the back door2is tipped up so that the back door2opens the rear opening.

When the back door2is positioned at the close position, a door latch device (not shown) provided at a lower central portion of the back door2is engaged with a striker (not shown) of the vehicle body1. With this the back door2is held at the close position.

There is provided an air damper7which is disposed between the vehicle body1and the back door2, and which includes an upper end portion pivotally supported by the back door2, and a lower end portion pivotally supported by the vehicle body1. The air damper7is arranged to provide an urging force in the open direction (that is, in the upward direction), to the back door2for relieving an operation force for moving the back door2in the open direction.

There is provided a power door opening/closing apparatus4which is provided at an upper portion of the rear opening of the vehicle body1, and which is arranged to electrically open and close the back door2by a power of a motor51described later.

As shown inFIG. 2toFIG. 5, the power door opening/closing apparatus4has a substantially cylindrical overall shape. The power door opening/closing apparatus4is mounted to the vehicle body1so that the power door opening/closing apparatus4has a central axis of the cylindrical shape which directs in leftward and rightward directions of the vehicle (leftward and rightward directions inFIG. 5). The power door opening/closing apparatus4includes a first unit5which includes electrical components including the motor51; and a second unit6which is a component different from the first unit5, and which does not include an electrical component. Besides, a leftward direction and a rightward direction which are used in below illustrations correspond to a leftward direction and a rightward direction inFIG. 5andFIG. 7.

As shown inFIG. 4andFIG. 7, the first unit5includes the motor51which is the electrical component; a cylindrical gear case52which includes a right end portion connected to a case513of the motor51; a planetary gear mechanism53which is a speed reduction mechanism that is received within the gear case52, and that constitutes a first transmission mechanism; a cylindrical clutch case54connected to a left end portion of the gear case52; an electromagnetic clutch55which is received within the clutch case54, which is the electrical component, and which constitutes the first transmission mechanism together with the planetary gear mechanism53; a rotation sensor assembly56which is the electrical component, and which is arranged to sense the opening operation and the closing operation of the back door2through various elements; and a sensor cover57closing a left end portion of the clutch case54.

Besides, the gear case52, the clutch case54, and the sensor cover57correspond to a first unit case in the present invention. However, the present invention is not limited to this embodiment. For example, the gear case52and the clutch case54may be integrally formed. That is, the first unit case can have any shapes as long as the first unit case can receive the speed reduction mechanism and/or the electromagnetic clutch55which constitute the transmission mechanism.

As shown inFIG. 4andFIG. 7, the gear case52is fixed to the case513of the motor51by two bolts501parallel to an axis (hereinafter, referred to as a “motor rotational axis O”) of a rotational shaft512of a rotor511of the motor51so that the central axis of the cylindrical shape of the gear case52corresponds to (is aligned with) the motor rotational axis O. The gear case52includes two mounting flap portions521which are integrally formed on an outer circumference surface of the gear case52, and which is for mounting the power door opening/closing apparatus4to the vehicle body1by bolts (not shown). Besides, the power door opening/closing apparatus4is fixed to the vehicle body1so that the mounting flap portions521are positioned on the upper side.

As shown inFIGS. 4,7, and8, the planetary gear mechanism53includes a planetary carrier plate531which is supported within the gear case52so as not to be rotated; a sun gear532connected to the rotational shaft512of the motor51; two planetary gears533which are rotatably supported by the planetary carrier plate531, and which are engaged with the sun gear532; and a ring gear534which is rotatably supported within the gear case52, and which includes internal teeth534bengaged with the planetary gears533.

The sun gear532includes a left end portion, and a right end, portion which is a shaft portion, and which is located at a position coaxial with the motor rotational axis O. The right end portion of the sun gear532is inserted into and connected to the rotational shaft512of the motor51so as not to be relatively rotated. Similarly, the left end portion of the sun gear532is rotatably inserted to a central hole of the planetary carrier plate531. With this, the sun gear532is rotated coaxially with the motor rotational axis O in accordance with the rotation of the rotational shaft512, so as to transmit this rotation to the planetary gears533.

The two planetary gears533are rotatably supported on the planetary carrier plate531supported within the gear case52so as not to be rotated, by shafts533cparallel to the motor rotational axis O. The two planetary gears533are engaged with the sun gear532and the internal teeth534bof the ring gear534. Each of the two planetary gears533is rotated around the corresponding one of the shafts533cin accordance with the rotation of the sun gear532. With this, the two planetary gears533transmit this rotation to the ring gear534. Besides, each of the planetary gears533has a teeth number of a teeth portion which is engaged with the internal teeth534bof the ring gear534, and which is smaller than a teeth number of a teeth portion which is engaged with the sun gear532, for increasing the reduction gear ratio of the planetary gear mechanism.

The ring gear534is rotationally supported within the gear case52coaxially with the motor rotational axis O. The ring gear534is engaged with the planetary gears533. The ring gear534is rotated around the motor rotational axis O to decrease the speed, in accordance with the rotations of the planetary gears533around the shafts533cby the rotation of the sun gear532. The ring gear534transmits this speed reduced rotation to a rotor552(described later) of the electromagnetic clutch55.

The clutch case54is fixed to the left end portion of the gear case52by four bolts502parallel to the motor rotational axis O so that the central axis of the cylindrical shape of the clutch case54corresponds to the motor rotational axis O.

The electromagnetic clutch55is received within the clutch case54. The electromagnetic clutch55includes a field core551which is fixed within the clutch case54, and which constitutes an electromagnet; a magnetic rotor552which is rotatably supported coaxially with the motor rotational axis O; and a magnetic armature553which is located adjacent to an attraction surface of the rotor552to confront the attraction surface of the rotor552, and which is rotatably supported coaxially with the motor rotational axis O.

The rotor552is rotatably supported within the clutch case54. The rotor552is rotatably supported to be rotated relative to a shaft554disposed coaxially with the motor rotational axis O. The rotor552includes a serration552awhich is formed on an outer circumference of an end portion of a cylindrical shape of a rotation shaft portion extending toward the ring gear534. This serration552aof the rotor552is mounted in a shaft hole534aof the ring gear534so as not to be rotated. By this serration552a, the rotor552is rotated as a unit with the ring gear534coaxially with the motor rotational axis O.

The armature553is supported to be rotated as a unit with the shaft554. The armature553includes a left side surface to which a sensor rotation plate561is fixed. The sensor rotation plate561is a part of the rotation sensor assembly56. The sensor rotation plate561includes a side surface on which a plurality of permanent magnets561aare fixed.

The electromagnetic clutch55is brought to a disconnection state in which the attraction surface of the rotor552and the attraction surface of the armature553are disconnected (separated) from each other, in a non-excited state in which the coil of the field core551is not energized (the current is not applied to the coil of the filed core551). With this, it is possible to manually perform the open operation and the close operation of the back door2. Moreover, in an excited state in which the coil of the field core551is energized (the current is applied to the coil of the field core551), the electromagnetic clutch55is brought to a connection state in which the armature553is attracted on the attraction surface of the rotor552, and the armature553and the rotor552are rotated as a unit with each other. With this, the rotation of the motor51is transmitted through an output lever65to the back door2to enable the electric open and close operation.

Besides, a first input portion corresponds to the sun gear532in this embodiment. Similarly, a first output portion corresponds to the armature553or the shaft554of the electromagnetic clutch55. However, the present invention is not limited to this embodiment. For example, in a case where the power door opening/closing apparatus4does not include the electromagnetic clutch55, the first output portion corresponds to the ring gear534.

The sensor cover57has a substantially disc shape. The sensor cover57is fixed to close the left end portion of the clutch case54by the bolts502parallel to the motor rotational axis O. A rotation sensor circuit board562is fixed on the sensor cover57. Rotation sensors (Hall elements)562aarranged to sense the rotation of the sensor rotation plate561, that is, the rotations of the permanent magnets561aare mounted to the rotation sensor circuit board562. The rotation sensors562asense a rotation angle and a rotation direction of the sensor rotation plate561rotating as a unit with the armature553. The detection signal of the rotation sensors562is transmitted to a control apparatus (not shown). By a calculation of the control apparatus, an opening and closing position and an opening and closing direction of the back door2are sensed. Besides, the rotation sensor assembly56is constituted by the sensor rotation plate561, the rotation sensor circuit board562, and the permanent magnets561a. Besides, the rotation sensors562amay be constituted by a rotary encoder, in place of the Hall element.

The second unit6includes a cylindrical gear case61which is connected to a left end portion of the clutch case54through the sensor cover57by bolts601which are fixing members parallel to the motor rotational axis O; a cover62which is fixed to a left end portion of the gear case61; a planetary gear mechanism63which is received within the gear case61, and which constitutes a second transmission mechanism; a mounting bracket64which is fixed on a left side surface of the cover62; and the output lever65which is for outputting the rotation of the motor51.

The gear case61has a cylindrical shape. The gear case61includes an inner circumference surface on which internal teeth611constituting a part of the planetary gear mechanism63is formed.

The cover62is fixed to the left end portion of the gear case61by the bolts602parallel to the motor rotation axis O. The cover62closes the left end portion of the gear case61.

Besides, the gear case61and the cover62in this embodiment correspond to a second unit case in the present invention. However, the present invention is not limited to this embodiment. For example, it is optional to employ a structure in which a ring gear including the internal teeth611formed on an inner circumference surface is fixed within the gear case61so as not to rotate.

The planetary gear mechanism63includes a first speed reduction section arranged to reduce the speed of the rotation outputted from the armature553of the electromagnetic clutch55, and a second speed reduction section arranged to further reduce the speed of the rotation of the first speed reduction section.

As shown inFIGS. 4,7, and9, the first speed reduction section includes the internal teeth611formed on the inner circumference surface of the gear case61; a first sun gear631which is arranged to rotate as a unit with the armature553of the electromagnetic clutch55; three first planetary gears632; a first planetary carrier plate633rotatably supporting the first planetary gears632.

The second speed reduction section includes the internal teeth611formed on the inner circumference surface of the gear case61; a second sun gear635which is arranged to rotate as a unit with the first planetary carrier plate633; three second planetary gears636; and a second planetary carrier plate637rotatably supporting the second planetary gears636.

The first sun gear631is mounted on a rectangular column portion554aformed at the left end portion of the shaft554. With this, the first sun gear631is rotated around the motor rotational axis O as a unit with the armature553of the electromagnetic clutch55through the shaft554.

The first planetary carrier plate633includes a central hole. A serration635aformed at an end portion of the second sun gear635is mounted in the central hole of the first planetary carrier plate633, so that the first planetary carrier plate633rotates as a unit with the second sun gear635.

Each of the first planetary gears632is supported on the first planetary carrier plate633by a shaft634parallel to the motor rotation axis O. Moreover, the first planetary gears632are engaged with the first sun gear631and the internal teeth611of the gear case61. With this, the first planetary gears632are rotated around the motor rotation axis O while each of the first planetary gears632is rotated around the corresponding one of the shafts634in accordance with the rotation of the first sun gear631rotating as a unit with the armature553. With this, the first planetary carrier plate633is rotated around the motor rotation axis O to reduce the speed by the rotation of the first planetary gears632around the motor rotation axis O, so that the first planetary carrier plate633transmits this speed reduced rotation to the second sun gear635.

As described above, the serration635aof the second sun gear635is mounted in the central hole of the first planetary carrier plate633. With this, the second sun gear635is rotated around the motor rotation axis O as a unit with the rotation of the first planetary carrier plate633, that is, the rotation of the first planetary gears632around the motor rotation axis O.

The second planetary carrier plate637includes a center hole637a. A serration66aformed at a right end portion of an output shaft66is mounted in this center hole637aof the second carrier plate637. With this, the second planetary carrier plate637is rotated around the motor rotation axis O as a unit with the output shaft66and the output lever65.

Each of the second planetary gears636is rotatably supported on the second planetary carrier plate637by a shaft638parallel to the motor rotation axis O. Moreover, the second planetary gears636are engaged with the second sun gear635and the internal teeth611of the gear case61. Each of the second planetary gears636is rotated around the motor rotation axis O while the each of the second planetary gears636is rotated around the corresponding one of the shafts638in accordance with the rotation of the second sun gear635rotating as a unit with the first planetary carrier plate633. With this, by the rotations of the second planetary gears636around the motor rotation axis O, the second planetary carrier plate637further reduces the speed of the rotation of the first speed reduction section, and rotates around the motor rotation axis O. Then, the second planetary carrier plate637transmits this rotation to the output shaft66.

Besides, the first sun gear631in this embodiment corresponds to a second input portion in the present invention. Similarly, the second planetary carrier plate637corresponds to a second output portion in the present invention. However, the present invention is not limited to this embodiment. For example, when the planetary gear mechanism63is constituted only by the first speed reduction section, the first planetary carrier plate633corresponds to the second output portion.

The output lever65is fixed at the left end portion of the output shaft66which protrudes from the left end surface of the cover62, by bolts603coaxially with the motor rotation axis O. With this, the output lever65is rotated as a unit with the output shaft66and the second planetary carrier plate637. The output lever65includes a spherical joint portion651provided at the end portion of the output lever65. The spherical joint portion651of the output lever65is connected to the door hinge3. With this, when the output lever65is pivoted a predetermined angle, the back door2is moved in the open direction or in the close direction.

The mounting bracket64is fixed to a left side surface of the cover62by the bolts602and bolts604. The mounting bracket64includes a mounting portion641which is provided at a front portion of the mounting bracket64, and which is tightened to the vehicle body1by bolts (not shown).

In the assembly operation of the power door opening/closing apparatus4, the first unit5and the second unit6are previously assembled independently. The sensor cover57fixed to the left end portion of the clutch case54of the assembled first unit5is connected to the right end portion of the gear case61of the second unit6by the bolts601. With this, at the same time, the rectangular column portion554aof the shaft554of the first unit5is connected to the first sun gear631of the second unit6. Besides, the sensor cover57includes a plurality of cylindrical protruding portions571(four in this embodiment) which are formed on the outer circumference surface of the sensor cover57, which protrude toward the gear case61, and in which the bolts601are screwed. Moreover, the gear case61includes a plurality of recessed portions612(cf.FIG. 9) (four in this embodiment) which are formed on the outer circumference surface of the gear case61at positions corresponding to the cylindrical protruding portions571of the sensor cover57, with which parts of the cylindrical protruding portions571are engaged, and which have recessed arc surfaces. Accordingly, in the joint operation of the sensor cover57and the gear case61, it is possible to accurately position the second unit6with respect to the first unit5by adjusting the cylindrical protruding portions571of the sensor cover57to the recessed portions612of the gear case61.

Next, the operation of the power door opening/closing apparatus4is illustrated.

In a case where the motor51and the electromagnetic clutch55are energized when the back door2is positioned at the close position (or the open position), the rotation shaft512of the motor51is rotated in the normal direction (or in the reverse direction). In the electromagnetic clutch55, the armature553is attracted on the rotor552to be brought to the connection state. With this, the rotation of the rotation shaft512of the motor51is inputted to the sun gear532of the planetary gear mechanism53of the first unit5. The speed of this rotation is reduced. The speed-reduced rotation is outputted from the ring gear534.

The rotation outputted from the ring gear534of the first unit5is transmitted to the electromagnetic clutch55which is in the connection state. This rotation is outputted from the shaft554rotating as a unit with the armature553. The rotation outputted from the shaft554is inputted to the first sun gear631of the planetary gear mechanism63of the second unit6. The speed of this rotation is further reduced. The speed-reduced rotation is transmitted to the second sun gear635rotating as a unit with the first planetary carrier plate633. The speed of the rotation of the second sun gear635is further reduced. This speed-reduced rotation is transmitted to the second planetary carrier plate637. The speed-reduced rotation of the second planetary carrier plate637is transmitted through the output shaft66to the output lever65. With this, the output lever65is rotated a predetermined angle around the motor rotation shaft0in the clockwise direction (or in the counterclockwise direction) inFIG. 6. With this, the back door2is moved from the close position (or the open position) in the open direction (or in the close direction) through the door hinge3.

When the electromagnetic clutch55is in the deenergized state, the electromagnetic clutch55is in the disconnection state. In this state, the open and close movement of the back door2by the manual operation is transmitted through the door hinge3, the output lever65, and the output shaft66to the planetary gear mechanism63of the second unit6. However, the open and close movement of the back door2by the manual operation is not transmitted to the planetary gear mechanism53and the motor51of the first unit5. Accordingly, it is possible to manually open and close the back door2by a light force.

As described above, the power door opening/closing apparatus4according to this embodiment of the present invention includes the first unit5including the electrical components such as the motor51, the electromagnetic clutch55, and the rotation sensor assembly56; and the second unit6which does not include the electric components. The first unit5and the second unit6are separately constituted. Accordingly, the confirmation of the actuation of the electrical components needs only for the first unit5. Consequently it is possible to readily perform the single confirmation of the actuation of the components. Therefore, it is possible to improve the productivity.

Moreover, even when the clutch case54is detached from the gear case52of the first unit5, the second unit6can be connected through the sensor cover57to the gear case52of the first unit5. Accordingly, the power door opening/closing apparatus4can be varied to a type in which the electromagnetic clutch55is provided, and a type in which the electromagnetic clutch55is not provided, if necessary.

Moreover, the gear case61of the second unit6includes the internal teeth611formed on the inner circumference surface of the gear case61. This internal teeth611is shared by the first speed reduction section and the second speed reduction section of the planetary gear mechanism63of the second unit6. Accordingly, it is possible to reduce the production cost. Moreover, the gear case61has the cylindrical shape having axial both ends which are opened. Accordingly, it is possible to mold the inner teeth611on the inner circumference surface of the gear case61at the high accuracy. Moreover, in a state where the planetary gear mechanism63except for the internal teeth611is previously assembled, it is possible to efficiently assemble the planetary gear mechanism63except for the internal teeth611within the gear case61.

Moreover, the power door opening/closing apparatus4has the substantially cylindrical overall shape. Accordingly, it is possible to decrease the size of the power door opening/closing apparatus4, and thereby to mount the power door opening/closing apparatus4to a small space.

Furthermore, all of the rotational elements and the bolts are parallel to the motor rotational axis O. Accordingly, it is possible to assemble the power door opening/closing apparatus4from one direction, and thereby to improve the productivity.

Moreover, the sun gear532, the ring gear534, and the armature553of the first transmission mechanism, and the first planetary gears632and the output shaft66of the second transmission mechanism are supported to be rotated coaxially with the motor rotation axis O. Accordingly, it is possible to efficiently perform the assembly operation of the power door opening/closing apparatus4.

Moreover, all of the central axes of the cylindrical shapes of the gear case52, the clutch case54, the sensor cover57, the gear case61, and the cover62correspond to the motor rotation axis O. Accordingly, it is possible to efficiently perform the assembly operation of the power door opening/closing apparatus4.

Furthermore, the second transmission mechanism is the planetary gear mechanism. The first and second sun gears631and635, and the first and second planetary carrier plates633and637are disposed coaxially with the motor rotation axis O. Accordingly, it is possible to efficiently dispose the planetary gear mechanism having the large speed reduction ratio within the cylindrical second unit case, that is, the gear case61.

Although the embodiment of the present invention has been described above by reference to the figures, the invention is not limited to the embodiments described above. Following various forms and modifications are included as long as they are not deviated from the gist of the invention.(1) The door which is electrically opened and closed by the power door opening/closing apparatus4may be a sliding door of a sliding type, and a side door of a swing type which are supported on the side surface of the vehicle body to be opened and closed, in place of the back door2.(2) The power door opening/closing apparatus4may have no electromagnetic clutch55.(3) The first transmission mechanism of the first unit5may be a cycloid speed reduction mechanism, in place of the planetary gear mechanism.(4) The second transmission mechanism of the second unit6may be a cycloid speed reduction mechanism, in place of the planetary gear mechanism.(5) The shaft554may be the second input portion, and the armature553may be the first output portion. In this case, the shaft554is rotatably supported within the gear case61. When the first unit5and the second unit6are connected, the shaft554is connected to the sensor rotation plate561and the armature553.(6) The sun gear631may be directly connected to the armature553without using the shaft554.

The entire contents of Japanese Patent Application No. 2013-128156 filed Jun. 19, 2013 are incorporated herein by reference.