JP2005324719A - Actuator for drive switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator for a drive switching device reducing the entire size and costs. <P>SOLUTION: The actuator 10 for the drive switching device has an actuator main body 11 housing: a drive gear 21 meshing with a worm gear of an armature shaft of a motor; an output shaft 22 connected to the drive gear and switching a drive state to any one state of two-wheel drive; four-wheel drive and differential lock, a coil spring 23 received in a spring housing formed on the drive gear; and a rotary retention member 24 held on the output shaft incapably of relative rotation and pressing the coil spring with a spring pressing portion. A first slide contact 25 is provided on the drive gear for detecting a position of the drive gear, and a second slide contact 27 is provided on the output shaft for detecting a position of the output shaft. A circuit board 40, on both surfaces of which predetermined patterns for contact and non-contact with the respective slide contacts are formed, is provided in the actuator main body facing the respective slide contacts. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an actuator for a drive switching device suitable for driving, for example, a two-wheel drive and a four-wheel drive drive switching device.

  For example, there is an actuator for a drive switching device shown in FIGS. 5 to 7 (see, for example, Patent Document 1).

  As shown in FIGS. 5 to 7, the drive switching device actuator 1 includes a motor 3 driven by energization in a box-shaped housing 2, and a rotational torque of a drive shaft 3 </ b> A of the motor 3 in the axial direction. A power transmission mechanism 4 that converts the output into a power and a rod as an output member that transmits a thrust according to the rotational torque of the motor 3 through the power transmission mechanism 4 and whose position is displaced according to the transmitted thrust. 5 and a drive shaft 3A of the motor 3 and a power transmission mechanism 4, and a reverse rotation prohibiting mechanism that prohibits rotation of the drive shaft 3A by power transmitted from the rod 5 side to the drive shaft 3A side. The cycloid gear 6, the motor-side rotating member 7 </ b> A to which the rotation of the drive shaft 3 </ b> A of the motor 3 is transmitted via the cycloid gear 6, and the cycloid gear 6 and the power transmission mechanism 4. And a rotational torque absorbing mechanism 7 that absorbs rotational torque due to the rotation of the motor 3 when the rod 5 cannot reciprocate, and is disposed between the rotational torque absorbing mechanism 7 and the drive shaft 3A. And a limit switch 8 as a first detecting means for detecting the rotation angle of the drive shaft 3A.

  The limit switch 8 detects the rotation angle of the drive shaft 3A, and the position of the rod 5 according to the three drive states of a two-wheel drive state, a four-wheel drive state, and a differential lock state of a drive switching device (not shown) is determined. It is to be detected. Further, the position switch 9 as the second detecting means is connected to the power transmission mechanism 4 and the rotational torque absorbing mechanism 7 so that the movement of the rod 5 can be detected based on the rotation of the power transmission mechanism 4 after the spiral spring 7B. In between.

JP 2003-289695 A

  However, in the conventional actuator 1 for the drive switching device, the limit switch 8 for detecting the rotation angle of the drive shaft 3A is provided between the drive shaft 3A and the rotational torque absorbing mechanism 7, and the position for detecting the movement of the rod 5 is provided. Since the switch 9 is provided separately between the power transmission mechanism 4 and the rotational torque absorbing mechanism 7, a large installation space for the detecting means is indispensable, and accordingly, the entire drive switching device actuator 1 becomes large. In addition, the number of parts increased and the cost increased.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide an actuator for a drive switching device that can reduce the overall size and cost.

  According to the first aspect of the present invention, a motor that rotates forward or backward by energization, a drive gear that meshes with a worm formed on an armature shaft of the motor, and a drive gear that is coupled to the drive gear, drive the vehicle to a two-wheel drive. , Four-wheel drive state and differential lock state output shaft, coil spring housed in a spring housing portion formed on the drive gear, and relative rotation on the output shaft A drive switching device comprising: a rotation holding member having a spring pressing portion that presses the coil spring by rotation of the drive gear; and an actuator body that houses the drive gear, the rotation holding member, and the output shaft, respectively. A first sliding contact for detecting the position of the drive gear is provided on the drive gear, and the output Provided with a second sliding contact for detecting the position of the output shaft, and the first sliding contact on the first surface in the actuator body opposite to the first and second sliding contacts. Forming a predetermined first pattern in which the second sliding contact is in contact or non-contact, and the second sliding contact is in contact with or non-contact with the second surface which is the back surface of the first surface. A circuit board on which each pattern is formed is provided.

  According to a second aspect of the present invention, there is provided the drive switching device actuator according to the first aspect, wherein the drive gear, the coil spring, and the rotation holding member are driven by the rotation of the motor when the output shaft is restrained and stopped. A waiting mechanism for accumulating the rotational torque is configured.

  As described above, according to the first aspect of the present invention, the predetermined first pattern is formed on the first surface, and the predetermined second pattern is formed on the second surface which is the back surface of the first surface. Detection is achieved by providing the first sliding contact for detecting the position of the drive gear and the second sliding contact for detecting the position of the output shaft so as to face each other with the circuit board on which the pattern is formed interposed therebetween. The installation space of the means can be made as small as possible, the number of parts can be reduced, and the entire actuator for the drive switching device can be reduced in size and cost.

  According to the second aspect of the present invention, the driving gear, the coil spring, and the rotation holding member constitute the waiting mechanism for accumulating the rotational torque of the driving gear due to the rotation of the motor when the output shaft is restrained and stopped. The drive switching device can be switched easily and reliably.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 is a cross-sectional view showing an actuator for a drive switching device according to an embodiment of the present invention, FIG. 2 is a bottom view of the actuator for the drive switching device, and FIG. 3 is a plan view with the cover of the actuator for the drive switching device removed. FIG. 4 is an explanatory view of the first sliding contact side of the actuator for the drive switching device, and FIG. 5 is an assembly state of the output shaft, drive gear, coil spring and rotation holding member of the actuator for the drive switching device. 1 is a view seen from below in FIG. 1, FIG. 6 is a view showing a rotation holding member of the actuator for the drive switching device, (A) is a plan view, and (B) is a BB sectional view in (A). 7 is an exploded perspective view showing an output shaft, a drive gear, and a circuit board of the actuator for the drive switching device, FIG. 8 is a view showing a circuit board of the actuator for the drive switching device, and FIG. ( ) Is a bottom view.

  As shown in FIGS. 1 to 8, the actuator 10 for a drive switching device includes a motor 30 that rotates forward or backward by energization, and a drive gear 21 that meshes with a worm 32 formed on an armature shaft 31 of the motor 30. The output shaft 22 is connected to the drive gear 21 and switches the driving state of the vehicle to any one of a two-wheel drive (2WD) state, a four-wheel drive (4WD) state, and a differential lock (DIFF LOCK) state. And a compression coil spring (coil spring) 23 housed in a concave spring housing part 21a formed in the drive gear 21 and a non-rotatable relative to the output shaft 22, and the compression coil spring 23 is held by a spring pressing part 24b. Rotating holding member 24 to be pressed, and a box-shaped housing storing drive gear 21, rotating holding member 24 and output shaft 22, respectively. And Chueta body 11, and a.

  As shown in FIG. 1, the actuator body 11 includes an actuator case 12 whose upper surface is open, and a first actuator cover that is fastened and fixed to the actuator case 12 via screws 15 and covers the opening 12 a of the actuator case 12. 13 and a second actuator cover 14 that is fastened and fixed to the first actuator cover 13 via a screw (not shown) and covers the opening 13 a of the first actuator cover 13. Then, the actuator case 12 of the actuator body 11 is fastened and fixed to a differential case of a differential device (not shown) via a bolt or the like (not shown), whereby the output shaft 22 exposed outside the central cylindrical portion 12c of the bottom portion 12b of the actuator case 12. A two-wheel drive and four-wheel drive switching device 50 provided in the differential case via a shift fork (not shown) linked to the base end portion 22f of the two-wheel drive state, the four-wheel drive state and the diff-lock state It can be switched to either state. That is, the drive switching device actuator 10 is used for driving when the drive switching device 50 is switched.

  As shown in FIG. 1, the small-diameter upper end 22 a of the output shaft 22 is rotatably supported by a bearing 16 a that is press-fitted into the central recess 14 a of the second actuator cover 14. Further, the large-diameter base portion 22 d of the output shaft 22 is rotatably supported via a bearing 16 b press-fitted into the cylindrical portion 12 c of the actuator case 12. The drive gear 21 is rotatably supported by a midway portion 22b of the output shaft 22 via a rotation holding member 24 that is held on the spline portion 22c at the center of the output shaft 22 so as not to be relatively rotatable. An annular groove portion 22e is formed below the base portion 22d of the output shaft 22, and an O-ring seal member 17 is fitted in the annular groove portion 22e.

  As shown in FIG. 5, on the same circumference of the lower surface of the drive gear 21, for example, a plurality (or one) of concave spring storage portions 21a may be formed in an arc shape at regular intervals. . In this embodiment, two spring accommodating portions 21a are formed. Each spring accommodating portion 21a accommodates a cylindrical compression coil spring 23 as a coil spring. Further, as shown in FIG. 1, a predetermined depth is reached from the lower surface of the drive gear 21 between both circumferential end surfaces of one spring housing portion 21a and both circumferential end surfaces of the other spring housing portion 21a. The slit 21b is formed. Each slit 21 b is for preventing interference with each spring pressing portion 24 b provided on the rotation holding member 24.

  As shown in FIGS. 5 and 6, the rotation holding member 24 is formed in a substantially disc shape, and an attachment hole 24 a to be fitted into the spline portion 22 c of the output shaft 22 is formed at the center thereof. In addition, a plurality of spring pressing portions 24b that are curved in an arc plate shape at equal intervals are integrally formed on the upper surface of the outer peripheral edge of the rotation holding member 24 so as to protrude upward. Each spring pressing portion 24b is normally positioned in each slit 21b of the drive gear 21.

  The output shaft 22 and the rotation holding member 24 of the drive switching device actuator 10 are normally rotated together in the same direction as the drive gear 21 is rotated by the rotation of the worm 32 of the armature shaft 31 of the motor 30. ing. However, when the motor 30 is energized and is restrained and stopped while the output shaft 22 is rotating forward or backward, the drive gear 21 continues to rotate forward or backward because the motor 30 continues to be energized. Try to continue. For this reason, either one of both end portions of each compression coil spring 23 is prevented from rotating by each spring pressing portion 24b of the rotation holding member 24 that stops together with the output shaft 22, but any one of both end portions of each compression coil spring 23 is stopped. The other is pressed by each spring pressing portion 24b, and each compression coil spring 23 is bent to be in a compressed state. When each compression coil spring 23 is in a compressed state, the drive gear 21 is restrained and stopped.

  In the case where the output shaft 22 of the drive switching device actuator 10 is restrained and stopped, the two-wheel drive and four-wheel drive drive switching device 50 is changed from a two-wheel drive (2WD) state to a four-wheel drive (4WD) state, When switching from the four-wheel drive (4WD) state to the differential lock (DIFF LOCK) state, for example, the two gears of the output shaft gear for the rear wheel of the differential device (not shown) and the front drive gear are out of phase. The spline fitting of both gears is canceled when the spline fitting of both gears cannot be performed with the four-wheel switching slider or when switching from the differential lock state to the four-wheel driving state to the four-wheel driving state to the two-wheel driving state. The spline engagement between the two gears may not be released because the power required for the two gears is too large, and the output shaft 22 and each compression coil are not released until these restrained states are released. By the respective compression coil spring 23 in a compressed state by the action of the waiting mechanism 20 consisting of a spring 23 and rotating the holding member 24, so as to accumulate a rotational torque of the driving gear 21 by the rotation of the motor 30.

  Then, when the spline fitting phase of both gears is matched in the two-wheel / four-wheel switching slide or when the power required for releasing the spline fitting is reduced, the compression coil springs that are in a compressed state are compressed. The output shaft 22 can be automatically rotated in one of the forward and reverse directions via the rotation holding member 24 by the elastic repulsive force 23.

  As shown in FIGS. 1 to 4, the motor 30 is attached to the actuator case 12 of the actuator body 11 via a screw 33, and the armature shaft 31 has a substantially semicircular cross section formed on the side wall of the actuator case 12. It is rotatably supported in the recess 12d via a bearing (not shown). The motor 30 is configured such that a current flows through an armature or the like (not shown) when energized, so that the armature shaft 31 rotates forward and backward.

  As shown in FIGS. 1, 4 and 7, a pair of first sliding contacts 25, 25 for detecting the position of the drive gear 21 are attached to the upper surface of the drive gear 21 via screws 26. In addition, a second sliding contact 27 for detecting the position of the output shaft 22 is attached to the middle portion 22 b of the output shaft 22 via a holder 28 and a screw 29. The pair of first sliding contacts 25, 25 are formed at equal distances in the radial direction from the rotation center of the drive gear 21, are formed at symmetrical positions, and have the same shape. Further, the holder 28 is supported by the middle portion 22b of the output shaft 22 so as not to be relatively rotatable. In the actuator main body 11 opposite to the first and second sliding contacts 25 and 27, the first end portion 25a of each first sliding contact 25 is in contact or non-contact with the first surface 40a. The first pattern 41 is formed, and the second surface 40b which is the back surface of the first surface 40a is in contact with or not in contact with the tip portion 27a of the second sliding contact 27. A circuit board 40 on which the patterns are formed is provided.

  As shown in FIG. 1, FIG. 4 and FIG. 7, each first sliding contact 25 is made of a leaf spring material, and the middle part is branched in a trifurcated shape. Moreover, it branches in the shape and forms the front-end | tip part 25a.

  In addition, as shown in FIGS. 1, 3 and 7, the second sliding contact 27 is also made of a leaf spring material, and the middle portion is branched in a trifurcated shape. The front end 27a is formed by branching into a bifurcated shape.

  As shown in FIGS. 4 and 8B, the first pattern 41 formed on the first surface (lower surface) 40a of the circuit board 40 includes an annular grounding fixed contact 41a and a 2WD detection fixing. A contact 41b, a differential lock (DIFF LOCK) detection fixed contact 41c, 2WD and 4WD intermediate position detection fixed contacts 41d and 4WD, and a differential lock intermediate position detection fixed contact 41e are provided. The fixed contact 41d and the fixed contact 41e are electrically connected.

  The distal end portion 25a of each first sliding contact 25 is always in contact with the ground fixed contact 41a, and the 2WD detection fixed contact 41b, the differential lock detection fixed contact 41c, and the intermediate position detection fixed contact between 2WD and 4WD. 41d and 4WD and the diff lock intermediate position detecting fixed contact 41e are in contact or non-contact depending on the rotational position of the drive gear 21.

  As shown in FIGS. 3 and 8A, the second pattern 42 formed on the second surface (upper surface) 40b of the circuit board 40 has an annular grounding fixed contact 42a and a pair of 4WD detections. Fixed contacts 42b, 42b and a pair of differential contacts (DIFF LOCK) detecting fixed contacts 42c, 42c. The pair of 4WD detection fixed contacts 42b and 42b are arranged at symmetrical positions, and the pair of differential lock detection fixed contacts 42c and 42c are also arranged at symmetrical positions. The pair of fixed contacts 42b and 42b are electrically connected, and the pair of fixed contacts 42c and 42c are also electrically connected.

  The tip 27a of each second sliding contact 27 is always in contact with the ground fixed contact 42a, and the 4WD detection fixed contacts 42b and 42b and the diff lock detection fixed contacts 42c and 42c are connected to the output shaft 22. Contact or non-contact depending on the rotational position.

  The circuit board 40 is formed in a substantially circular ring shape, and is fastened and fixed to the back surface of the first actuator cover 13 via screws 43. A round hole 40c is formed in the center of the circuit board 40, and the cylindrical portion 28a of the holder 28 is passed through the round hole 40c. The arm portion 28 b of the holder 28 to which the second sliding contact 27 is fastened and fixed is housed in the circular opening 13 a of the first actuator cover 13.

  As shown in FIG. 1, the upper surface of the peripheral wall of the actuator case 12 and the lower surface of the peripheral edge of the first actuator cover 13 are sealed with a seal member 18. Further, the upper surface around the opening 13 a of the first actuator cover 13 and the lower surface of the second actuator cover 14 are sealed by a seal member 19.

  According to the actuator 10 for a drive switching device of the above embodiment, as shown in FIG. 2, if the output shaft 22 is in a two-wheel drive (2WD) state, each first sliding in FIGS. The distal end portion 25a of the contact 25 is in contact with the ground fixed contact 41a and the 2WD detection fixed contact 41b, and is provided between the differential lock detection fixed contact 41c, the intermediate position detection fixed contact 41d between 2WD and 4WD, and the middle of the differential lock. It is not in contact with the position detection fixed contact 41e. The tip 27a of the second sliding contact 27 is in contact with the ground fixed contact 42a, and the 4WD detection fixed contacts 42b and 42b and the differential lock detection fixed contacts 42c and 42c are not in contact with each other. This contact state is a state in which energization to the motor 30 is cut off.

  In this state, when a changeover switch (not shown) is switched to the 4WD side, the motor 30 is energized, the armature shaft 31 rotates forward, and the drive gear 21 meshing with the worm 32 rotates forward. Due to the forward rotation of the drive gear 21, the rotation holding member 24 and the output shaft 22 are rotated forward (rotation in the counterclockwise direction in FIG. 2) via the compression coil spring 23. When the output shaft 22 comes to an intermediate position between 2WD and 4WD, the tip end portion 25a of the first sliding contact 25 and the intermediate position detection fixed contact 41d between 2WD and 4WD are switched from the non-contact state to the contact state.

  When the output shaft 22 rotates forward by 32 °, the drive switching device 50 switches to a four-wheel drive (4WD) state by spline fitting of two gears, a rear wheel output gear and a front drive gear (not shown). At this time, the front end portion 25a of the first sliding contact 25 and the 2WD detection fixed contact 41b are switched from the contact state to the non-contact state, and the front end portion 25a and the intermediate position detection fixed contact 41d of the 2WD and 4WD are also changed. The contact state is switched to the non-contact state. Further, the front end portion 27a of the second sliding contact 27 and the 4WD detection fixed contacts 42b and 42b are switched from the non-contact state to the contact state, whereby the energization to the motor 30 is cut off.

  If the two gears are out of phase and the splines cannot be engaged with each other, the output shaft 22 cannot rotate forward to 32 ° and stops in the middle. The distal end portion 27a of 27 and the 4WD detection fixed contacts 42b and 42b remain in a non-contact state. However, since the motor 30 is energized, the drive gear 21 continues to rotate forward, and the rotation pressing torque of the drive gear 21 causes the spring pressing portion 24b of the rotation holding member 24 to press one end of the compression coil spring 23 so that the compression is performed. The coil spring 23 is compressed. For this reason, the front end portion 25a of the first sliding contact 25 and the 2WD detection fixed contact 41b are switched from the contact state to the non-contact state, and the energization to the motor 30 is cut off. That is, the rotational torque of the drive gear 21 is stored as a restoring force of the compressed compression coil spring 23 that constitutes the waiting mechanism 20. When the two gears are in phase, when the output shaft 22 rotates forward 32 ° by the restoring force of the compression coil spring 23, the gears are spline-fitted by the drive switching device 50 and the four-wheel drive (4WD). The tip portion 27a of the second sliding contact 27 and the 4WD detection fixed contacts 42b and 42b are switched from the non-contact state to the contact state.

  Next, when a changeover switch (not shown) is switched to the differential lock side to change the 4WD state to the differential lock state, the motor 30 is energized, the armature shaft 31 further rotates forward, and the drive gear 21 and the output shaft 22 are positive. Rotate. When the output shaft 22 comes to an intermediate position between the 4WD and the diff lock, the distal end portion 25a of the first sliding contact 25 and the fixed contact 41e for detecting the intermediate position between the 4WD and the diff lock are switched from the non-contact state to the contact state. The distal end portion 27a of the second sliding contact 27 and the 4WD detection fixed contacts 42b and 42b are switched from the contact state to the non-contact state.

  As shown in FIG. 2, when the output shaft 22 rotates 32 ° forward (counterclockwise in FIG. 2) from the position of 4WD, the state is switched to the diff lock (DIFF LOCK) state. At this time, the tip 25a of the first sliding contact 25 and the diff lock detecting fixed contact 41c are switched from the non-contact state to the contact state, and the tip 25a, 4WD and the diff lock intermediate position detecting fixed contact 41e are The contact state is switched to the non-contact state. In addition, the tip 27a of the second sliding contact 27 and the differential lock detection fixed contacts 42c, 42c are switched from the non-contact state to the contact state, and the energization to the motor 30 is cut off.

  Next, when a changeover switch (not shown) is switched to the 4WD side so as to change the differential lock state to the 4WD state, the motor 30 is energized, the armature shaft 31 rotates reversely, and the drive gear 21 and the output shaft 22 rotate reversely. (Clockwise rotation in FIG. 2). When the output shaft 22 comes to an intermediate position between the 4WD and the diff lock, the distal end portion 25a of the first sliding contact 25 and the fixed contact 41e for detecting the intermediate position between the 4WD and the diff lock are switched from the non-contact state to the contact state.

  As shown in FIG. 2, when the output shaft 22 rotates 32 ° backward (clockwise in FIG. 2) from the position of DIFF LOCK, the output shaft 22 is switched to the 4WD state. At this time, the tip 25a of the first sliding contact 25 and the diff lock detecting fixed contact 41c are switched from the contact state to the non-contact state, and the tip 25a, 4WD and the diff lock intermediate position detecting fixed contact 41e are The contact state is switched to the non-contact state. Further, the tip 27a of the second sliding contact 27 and the 4WD detection fixed contacts 42b and 42b are switched from the non-contact state to the contact state, and the tip 27a of the second sliding contact 27 and the differential lock detection fixed contact. 42c and 42c are switched from a contact state to a non-contact state, and energization to the motor 30 is cut off.

  Next, in order to change from the 4WD state to the 2WD state, when a changeover switch (not shown) is switched to the 2WD side, the motor 30 is energized, the armature shaft 31 further rotates in reverse, and the drive gear 21 and the output shaft 22 are reversed. It rotates (clockwise in FIG. 2). When the output shaft 22 comes to an intermediate position between 2WD and 4WD, the tip end portion 25a of the first sliding contact 25 and the intermediate position detection fixed contact 41d between 2WD and 4WD are switched from the non-contact state to the contact state.

  As shown in FIG. 2, when the output shaft 22 reversely rotates 32 ° from the 4WD position (clockwise rotation in FIG. 2), the drive switching device 50 causes the spline of two gears, the rear wheel output gear and the front drive gear. Release the fitting and switch to the 2WD state. At this time, the distal end portion 25a of the first sliding contact 25 and the 2WD detection fixed contact 41b are switched from the non-contact state to the contact state, and the intermediate position detection fixed contact 41d between the distal end portion 25a, 2WD and 4WD is The contact state is switched to the non-contact state. Further, the tip 27a of the second sliding contact 27 and the 4WD detection fixed contacts 42b and 42b are switched from the contact state to the non-contact state, and the energization to the motor 30 is cut off.

  If the power required for releasing the spline fitting between the two gears is too large to release the spline fitting between the two gears, the output shaft 22 cannot rotate backward up to 32 °, and the restraint stops midway. Therefore, the distal end portion 27a of the second sliding contact 27 and the 4WD detection fixed contacts 42b and 42b remain in contact with each other. However, since the motor 30 is energized, the drive gear 21 continues to rotate in the reverse direction, and the rotational pressure of the drive gear 21 causes the spring pressing portion 24b of the rotation holding member 24 to press the other end of the compression coil spring 23. The coil spring 23 is compressed. For this reason, the front end portion 25a of the first sliding contact 25 and the 2WD detection fixed contact 41b are switched from the non-contact state to the contact state, and the energization to the motor 30 is cut off. The rotational torque of the drive gear 21 is stored as a restoring force of the compressed compression coil spring 23 that constitutes the waiting mechanism 20. When the power required for releasing the spline fitting between the two gears is reduced, the spline fitting between the two gears is released by the drive switching device 50 when the output shaft 22 reversely rotates 32 ° by the restoring force of the compression coil spring 23. Thus, the state is switched to the two-wheel drive (2WD) state, and the tip end portion 27a of the second sliding contact 27 and the 4WD detection fixed contacts 42b and 42b are switched from the contact state to the non-contact state.

  Note that switching from the two-wheel drive state to the diff lock state and from the diff lock state to the two-wheel drive state is performed via switching to the four-wheel drive state.

  As described above, in the drive switching device actuator 10, the output shaft 22 is rotated counterclockwise and clockwise by the motor 30, so that one of the two-wheel drive state, the four-wheel drive state, and the diff lock state is selected. You can easily switch to the state automatically.

  In addition, the predetermined first pattern 41 is formed on the first surface 40a, and the position of the drive gear 21 is detected with the circuit board 40 formed with the predetermined second pattern 42 formed on the second surface 40b. By providing the pair of first sliding contacts 25, 25 and the second sliding contact 27 for detecting the position of the output shaft 22 so as to face each other, the installation space of the detecting means is made as much as possible. In addition, the number of parts can be reduced, and the entire drive switching device actuator 10 can be reduced in size and cost.

  Furthermore, the waiting mechanism 20 that stores the rotational torque of the driving gear 21 due to the rotation of the motor 30 when the restraint of the output shaft 22 is stopped is constituted by the driving gear 21, the compression coil spring 23, and the rotation holding member 24. The actuator main body 11 can be housed in a compact manner, and the drive switching device 50 can be switched easily and reliably. Further, in order to hold the rotation holding member 24 on the output shaft 22 so as not to be relatively rotatable, the mounting hole 24a of the rotation holding member 24 is fitted and fixed to the spline portion 22c formed on the output shaft 22, and the output shaft 22 is rotated. The waiting mechanism 20 can be easily assembled simply by accommodating the compression coil spring 23 in the spring accommodating portion 21a of the drive gear 21 that is freely supported, and the assembling workability can be improved. 20 becomes a small size, the number of parts is reduced, and the actuator 10 for a drive switching device becomes smaller and less expensive.

  Further, by storing the compression coil spring 23 in the spring storage portion 21a of the drive gear 21, the compression coil spring 23 functions as a damper that absorbs an impact force when the output shaft 22 is restrained and stopped. It is possible to prevent the components constituting the drive switching device actuator 10 from being damaged.

  In addition, according to the embodiment, the actuator for the two-wheel drive and the four-wheel drive switching device used for the part-time 4WD that can drive the four-wheels only when necessary in the two-wheel drive vehicle has been described. Of course, the above-described embodiment can be applied to actuators for two-wheel drive and four-wheel drive drive switching devices used in 4WD other than 4WD.

It is sectional drawing which shows the actuator for drive switching apparatuses of one Embodiment of this invention. It is a bottom view of the actuator for the drive switching device. It is a top view in the state where the cover of the actuator for the above-mentioned drive change device was removed. It is explanatory drawing by the side of the 1st sliding contact of the said actuator for drive switching devices. FIG. 2 is a view showing an assembled state of an output shaft, a drive gear, a coil spring, and a rotation holding member of the actuator for the drive switching device, as viewed from below in FIG. It is a figure which shows the rotation holding member of the said actuator for drive switching apparatuses, (A) is a top view, (B) is BB sectional drawing in (A). It is a disassembled perspective view which shows the output shaft of the said actuator for drive switching apparatuses, a drive gear, and a circuit board. It is a figure which shows the circuit board of the said actuator for drive switching apparatuses, (A) is a top view, (B) is a bottom view. It is a schematic sectional drawing of the conventional drive switching device actuator. It is a top view of the said conventional drive switching device actuator. It is a schematic block diagram of the said conventional drive switching device actuator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Actuator for drive switching devices 11 Actuator body 20 Waiting mechanism 21 Drive gear 21a Spring accommodating part 22 Output shaft 23 Compression coil spring (coil spring)
24 Rotation holding member 24b Spring pressing portion 25 First sliding contact 25a Tip portion 27 Second sliding contact point 27a Tip portion 30 Motor 31 Armature shaft 32 Worm 40 Circuit board 40a First surface 40b Second surface 41 First 1 pattern 41a, 41b, 41c fixed contact 42 2nd pattern 42a, 42b, 42c fixed contact

Claims (2)

A motor that rotates forward or backward by energization, a drive gear that meshes with a worm formed on the armature shaft of the motor, and a drive gear that is connected to the drive gear, and changes the vehicle drive state between a two-wheel drive state and a four-wheel drive state. An output shaft that switches between the state and the differential lock state, a coil spring that is housed in a spring housing portion formed on the drive gear, and a rotation of the drive gear that is held on the output shaft so as not to be relatively rotatable. An actuator for a drive switching device comprising: a rotation holding member having a spring pressing portion that presses the coil spring; and an actuator body that houses the drive gear, the rotation holding member, and the output shaft.
The driving gear is provided with a first sliding contact for detecting the position of the driving gear, and the output shaft is provided with a second sliding contact for detecting the position of the output shaft. A predetermined first pattern in which the first sliding contact is in contact with or non-contacting is formed on the first surface in the actuator body facing the sliding contact, and the back surface of the first surface An actuator for a drive switching device, comprising a circuit board on which a predetermined second pattern is formed on the second surface to be in contact or non-contact with the second sliding contact. An actuator for a drive switching device according to claim 1,
The drive switching device actuator, wherein the drive gear, the coil spring, and the rotation holding member constitute a waiting mechanism for accumulating rotational torque of the drive gear due to rotation of the motor when the output shaft is restrained and stopped. .

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