JP2018043633A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission device capable of stably maintaining a driving switching state of a vehicle.SOLUTION: A power transmission device includes: a shaft 11 which is rotated by driving force from a driving source 1; a slide gear 20 which is rotatable integrally with the shaft 11 and relatively movable in an axial direction with respect to the shaft 11; a hub 12 which is integrally provided with an outer gear 21 engageable with the slide gear 20 and is rotated together with a wheel 9; a transmission cutoff mechanism 13 which enables rotation transmission between the shaft 11 and the hub 12 by engaging the slide gear 20 with the outer gear 21 by relatively moving the slide gear 20 in the axial direction with respect to the shaft 11 while releasing the engagement so as to cut off the rotation transmission; and a lock mechanism 14 which locks the transmission cutoff mechanism 13 at either a position for engaging the slide gear 20 with the outer gear 21 or a position for releasing the engagement of the slide gear 20 with the outer gear 21.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power transmission device.

  In vehicles such as automobiles, a power transmission device having a freewheel function that can switch between a two-wheel drive state and a four-wheel drive state may be employed (see, for example, Patent Document 1). In the power transmission device of Patent Document 1, in the two-wheel drive state, the driven wheel is set in a free state where the driven wheel is disconnected from the driven axle, and the running resistance received from the driven wheel is cut off while the driven wheel is driven in the four-wheel drive state. The side wheels and the driven axle are locked, and the driving force from the engine can be transmitted to the driven wheels.

  The power transmission device is employed in, for example, a four-wheel vehicle shown in FIG. This vehicle includes a transfer 5 that can be switched between a two-wheel drive state and a four-wheel drive state by operating a switching mechanism 4 by a transfer lever 3. In the two-wheel drive state, the driving force is transmitted to the rear wheel 9b, while the switching mechanism 4 blocks the transmission of the driving force from the transfer 5 to the front propeller shaft 6a. On the other hand, in the four-wheel drive state, the driving force is transmitted to the rear wheel 9b and from the transfer 5 via the front propeller shaft 6a, the front differential 7a, the front axle 8a (shaft 11), and the power transmission device 100. The driving force is also transmitted to the front wheel 9a.

  As shown in FIGS. 10 and 11, the power transmission device 100 includes a shaft 101 that rotates by a driving force from the engine 1 (see FIG. 2), and a hub 102 that rotates around an axis together with the front wheels 9a (see FIG. 2). The transmission blocking mechanism 103 capable of connecting and blocking the rotation transmission between the shaft 101 and the hub 102 is a main component. The shaft 101 is provided with a slide gear 106 that is relatively movable in the axial direction. The hub 102 is integrally provided with an outer gear 107 that can be engaged with the slide gear 106 and is rotatable about an axis.

  The transmission blocking mechanism 103 engages the slide gear 106 and the outer gear 107 to enable rotation transmission between the shaft 101 and the hub 102, while releasing the engagement between the slide gear 106 and the outer gear 107. The rotation transmission is cut off.

  An internal space (negative pressure chamber) of the transmission blocking mechanism 103 is divided into a two-wheel drive negative pressure chamber 108 and a four-wheel drive negative pressure chamber 109 by a diaphragm 110. The two-wheel drive negative pressure chamber 108 is connected to the two-wheel drive negative pressure port 112 via the two-wheel drive negative pressure path 111, and the four-wheel drive negative pressure chamber 109 is connected to the four-wheel drive negative pressure path 113 via the four-wheel drive negative pressure path 113. It is connected to the wheel drive negative pressure port 114. A pressure receiving plate 115 made of a magnetic material is provided on the two-wheel drive negative pressure chamber 108 side of the diaphragm 110, and a piston 116 is provided on the four-wheel drive negative pressure chamber 109 side. The diaphragm 110, the pressure receiving plate 115, and the piston 116 are integrated by a rivet 117, and the pressure receiving plate 115 and the piston 116 move in the axial direction as the diaphragm 110 moves in the axial direction. The piston 116 is provided with a slide gear 106 that can move integrally in the axial direction, and the slide gear 106 moves in the same direction as the piston 116 moves in the axial direction.

  A yoke 118 made of a magnetic material is fixed inside the cover 104, and a cylindrical adsorption portion 118 a that stands so as to face the pressure receiving plate 115 is formed at the inner peripheral end of the yoke 118. The yoke 118 is provided with a magnet 119 that imparts magnetism to the yoke 118 (attraction portion 118a). A coil spring 120 is interposed between the yoke 118 and the pressure receiving plate 115. The coil spring 120 biases the pressure receiving plate 115 (diaphragm 110, piston 116) in a direction in which the pressure receiving plate 115 is separated from the yoke 118.

  In the two-wheel drive state (see FIG. 10), the two-wheel drive negative pressure chamber 108 is in a negative pressure state, and the diaphragm 110 moves to the two-wheel drive negative pressure chamber 108 side. Along with this movement, the engagement between the slide gear 106 and the outer gear 107 is released and the transmission of the rotational force between the shaft 101 and the hub 102 is switched to the two-wheel drive state, and as shown in FIG. As described above, the pressure receiving plate 115 is attracted to the yoke 118 by the magnetic force to the attracting portion 118a. When the switching to the two-wheel drive state is completed, the two-wheel drive negative pressure chamber 108 is opened to the atmosphere, and the two-wheel drive state is maintained only by the attraction force of the yoke 118.

  On the other hand, in the four-wheel drive state (see FIG. 11), the four-wheel drive negative pressure chamber 109 is in a negative pressure state, and the diaphragm 110 moves to the four-wheel drive negative pressure chamber 109 side. Along with this movement, the slide gear 106 and the outer gear 107 are engaged to switch to the four-wheel drive state in which the rotational force can be transmitted from the shaft 101 to the hub 102. When the switching to the four-wheel drive state is completed, the four-wheel drive negative pressure chamber 109 is opened to the atmosphere, and the four-wheel drive state is maintained only by the urging force of the coil spring 120.

Japanese Patent Laid-Open No. 10-278621

  However, in the power transmission device of Patent Document 1, since the two-wheel drive state is held only by the attraction force by the magnet 119, when the vehicle is subjected to an impact such as over a step, the pressure receiving plate 115 is the yoke. There is a risk that it will deviate from 118. When the pressure receiving plate 115 is detached from the yoke 118, the two-wheel drive state is switched to the four-wheel drive state regardless of the biasing force of the coil spring 120.

  Accordingly, an object of the present invention is to stably maintain a drive switching state in a vehicle power transmission device.

  In order to solve this problem, in the present invention, a shaft that is arranged along a central axis and that rotates around the axis by a driving force from a driving source, can rotate integrally around the shaft, and can rotate around the axis; A slide gear that can move relative to the shaft in the axial direction, and an outer gear that can be engaged with the slide gear are provided integrally, a hub that rotates around the axis together with a wheel, and the slide gear that moves relative to the shaft. The slide gear and the outer gear are engaged with each other by relatively moving in the axial direction to enable rotation transmission between the shaft and the hub, while the slide gear and the outer gear are engaged. A position where the slide gear and the outer gear are engaged, or A locking mechanism for locking in any position position and Raidogia releasing the engagement of said outer gear, to constitute a power transmission device provided with a.

  In this way, by providing a lock mechanism that locks the position of the transmission cutoff mechanism, even when an impact is applied to the vehicle, the engagement state or the disengagement state of the slide gear and the outer gear is prevented from being inadvertently switched. Thus, the drive switching state of the vehicle can be stably maintained.

  In the above-described configuration, the transmission blocking mechanism holds a magnetized yoke, an adsorption member facing the yoke in the axial direction, the adsorption member, and can move the slide gear in the axial direction. And when the engagement between the slide gear and the outer gear is released, the yoke is sandwiched between the lock mechanism and the adsorption member, and the adsorption member is the yoke. It is preferable that a relative movement in the axial direction of the yoke and the suction member is prevented by being attracted to the yoke.

  As described above, the yoke is sandwiched between the lock mechanism and the suction member, so that the suction member and the yoke are prevented from being separated in the axial direction due to an impact applied to the vehicle, and the driving state of the vehicle is reliably ensured. Can be maintained.

  In the above configuration, the rivet is interposed between the fixed rivet holding the suction member, the slide rivet slidably inserted in the fixed rivet, and between the fixed rivet and the slide rivet. A rivet spring that urges the rivets axially opposite to each other, and the locking mechanism is rotatably provided on the fixed rivet, and an engaging protrusion formed on the fixed piece. An engagement groove formed on the slide rivet and engageable with the engagement protrusion. When the rivet spring is extended, the engagement protrusion engages with the engagement groove. In a state where the rivet spring is shortened, it is preferable that the engagement protrusion is retracted from the engagement groove.

  Thus, by sliding the slide rivet relative to the fixed rivet, the engagement state between the engagement protrusion and the engagement groove can be switched very smoothly.

  In the configuration employing the rivet, the transmission blocking mechanism has a first negative pressure chamber that becomes negative pressure when the engagement between the slide gear and the outer gear is released, and the slide gear. A second negative pressure chamber that becomes negative pressure when engaged with the outer gear, and a diaphragm held by the rivet; a diaphragm spring that biases the diaphragm toward the second negative pressure chamber; It is preferable to further include

  In this way, by driving the suction member with the negative pressure acting on the diaphragm, the driving force of the vehicle can be reliably switched with a simple configuration.

  The power transmission device according to the present invention has an engagement state or a disengagement state of the slide gear provided on the shaft and the outer gear provided on the hub in the transmission cutoff mechanism that connects or blocks the rotational transmission between the shaft and the hub. Since the lock mechanism that can lock the vehicle is employed, the drive switching state of the vehicle can be stably maintained even when an impact is applied to the vehicle.

Sectional drawing which shows one Embodiment of the power transmission device which concerns on this invention Overall configuration diagram of a vehicle including the power transmission device shown in FIG. Sectional drawing which shows the principal part of the power transmission device shown in FIG. 1 in case a vehicle is a two-wheel drive state Enlarged view around the lock mechanism shown in FIG. The perspective view of the lock mechanism (locked state) of the power transmission device shown in FIG. Sectional drawing which shows the state in the middle of the lock mechanism shown in FIG. 3 being unlocked Section showing a main part of the power transmission device shown in FIG. 1 when the vehicle is in a two-wheel drive state Enlarged view around the lock mechanism shown in FIG. The perspective view of the lock mechanism (lock release state) of the power transmission device shown in FIG. Sectional drawing which shows an example (two-wheel drive state) of the power transmission device which concerns on a prior art Sectional drawing which shows an example (four-wheel drive state) of the power transmission device which concerns on a prior art Sectional drawing which shows the principal part of the power transmission device shown in FIG.

  An embodiment of a power transmission device 10 according to the present invention is shown in FIG. This power transmission device 10 is employed, for example, in a vehicle 50 shown in FIG. The vehicle 50 includes an engine 1, a transmission 2, a transfer mechanism 5 that can be switched between a two-wheel drive state and a four-wheel drive state by operating a switching mechanism 4 with a transfer lever 3, and wheels 9 a and 9 b. I have.

  In the two-wheel drive state, the driving force is transmitted from the transfer 5 to the rear wheel 9b via the rear propeller shaft 6b, the rear differential 7b, and the rear axle 8b. Transmission of driving force from the transfer 5 to the front propeller shaft 6a is interrupted. On the other hand, in the four-wheel drive state, the driving force is transmitted to the rear wheel 9b, and from the transfer 5 through the front propeller shaft 6a, the front differential 7a, the front axle 8a (shaft 11), and the power transmission device 10. The driving force is also transmitted to the front wheel 9a.

  As shown in FIG. 1, the power transmission device 10 of the vehicle 50 includes a shaft 11 that rotates around an axis by a driving force of an engine as the drive source 1, a hub 12 that rotates around the axis together with wheels 9 a, and a shaft 11. A transmission blocking mechanism 13 capable of connecting and blocking rotation transmission to and from the hub 12 and a lock mechanism 14 are main components. The shaft 11 and the transmission cutoff mechanism 13 are accommodated in a hub 12, a cover 15 provided integrally with the hub 12, and a spindle 16. The shaft 11 is provided with a bush 19 so that the shaft 11 can rotate smoothly around the axis with respect to the spindle 16. The hub 12 and the cover 15 are integrally fastened by bolts 17. A bearing 18 is interposed between the hub 12 and the spindle 16, and the hub 12 and the spindle 16 can rotate relative to each other around the axis.

  A slide gear 20 is provided on the shaft 11. A guide groove 11 a for guiding the slide gear 20 in the axial direction is formed in the shaft 11. The slide gear 20 is formed with a guide protrusion 20a guided by the guide groove 11a. The slide gear 20 can move relative to the shaft 11 in the axial direction, and can rotate about the axis integrally with the shaft 11. The hub 12 is provided with an outer gear 21 that can be engaged with the slide gear 20 so as to be integral with the hub 12 and rotatable about an axis.

  The transmission cutoff mechanism 13 engages the slide gear 20 and the outer gear 21 by moving the slide gear 20 relative to the shaft 11 in the axial direction, and enables rotation transmission between the shaft 11 and the hub 12. On the other hand, it has a function of releasing the engagement between the slide gear 20 and the outer gear 21 to block the rotation transmission.

  The internal space (negative pressure chamber) of the transmission cutoff mechanism 13 is partitioned into a first negative pressure chamber 22 and a second negative pressure chamber 23 by a diaphragm 24. The first negative pressure chamber 22 is a two-wheel drive negative pressure chamber that becomes negative pressure when the engagement of the slide gear 20 and the outer gear 21 is released. The second negative pressure chamber 23 is a four-wheel drive negative pressure chamber that becomes negative pressure when the slide gear 20 and the outer gear 21 are engaged. The two-wheel drive negative pressure chamber 22 and the four-wheel drive negative pressure chamber 23 are hermetically sealed by seal members 44, 45, and 46.

  The two-wheel drive negative pressure chamber 22 is connected to the two-wheel drive negative pressure port 26 via the two-wheel drive negative pressure path 25, and the four-wheel drive negative pressure chamber 23 is connected to the four-wheel drive negative pressure path 27 via the four-wheel drive negative pressure path 27. The wheel drive negative pressure port 28 is connected. The two-wheel drive negative pressure path 25 and the four-wheel drive negative pressure path 27 are provided with timer-controlled shut-off valves (not shown). This shut-off valve is a two-wheel drive negative pressure in a negative pressure state when a predetermined time elapses after the negative pressure in the two-wheel drive negative pressure path 25 or the four-wheel drive negative pressure path 27 becomes constant. The chamber 22 or the four-wheel drive negative pressure chamber 23 is opened to the atmosphere.

  A pressure receiving plate 29 is provided on the two-wheel drive negative pressure chamber 22 side of the diaphragm 24, and a piston 30 is provided on the four-wheel drive negative pressure chamber side 23. The pressure receiving plate 29 is provided between a later-described yoke 38 and the piston 30 in the axial direction. The pressure receiving plate 29 is an attracting member that is attracted to the yoke 38 when the engagement between the slide gear 20 and the outer gear 21 is released. The piston 30 is integrally provided with a slide gear 20, and the slide gear 20 moves in the axial direction as the piston 30 moves in the axial direction. The diaphragm 24, the pressure receiving plate 29, and the piston 30 are integrated with a rivet 31, and move together with the rivet 31 in the axial direction.

  As shown in FIGS. 3 to 5, the rivet 31 has a fixed rivet 32, a slide rivet 33, and a rivet spring 34. The fixed rivet 32 has a cylindrical shape, and a fixing portion 32a for fixing the diaphragm 24, the pressure receiving plate 29, and the piston 30 is formed on the outer peripheral surface thereof. The fixed portion 32a is annular and is recessed from the outer peripheral surface toward the inner peripheral surface. The fixed rivet 32 is opened on the opposite side to the shaft 11, and the slide rivet 33 can be inserted therein. A packing 35 interposed between the fixed rivet 32 and the slide rivet 33 is provided on the inner peripheral surface of the fixed rivet 32, and the packing 35 is provided between the two-wheel drive negative pressure chamber 22 and the four-wheel drive negative pressure chamber 23. Airtightness is ensured.

  The slide rivet 33 has a cylindrical portion 33a and a flange portion 33b. The cylindrical portion 33a is inserted into the fixed rivet 32 so as to be slidable in the axial direction. The flange portion 33b extends radially outward from one axial end portion (opening side of the fixed rivet 32) of the cylindrical portion 33a. A concave engagement groove 37 is formed on the outer end face in the axial direction of the flange portion 33b. As will be described later, the engagement groove 37 constitutes the lock mechanism 14. The rivet spring 34 is interposed between the fixed rivet 32 and the slide rivet 33 and urges the rivets 32 and 33 in the opposite axial direction.

  As shown in FIGS. 1 and 3, a yoke 38 made of a magnetic material is fixed inside the cover 15, and an inner peripheral end of the yoke 38 faces an adsorption member (pressure receiving plate) 29. An upright cylindrical suction portion 39 is formed. The yoke 38 is provided with a magnet 40, and the magnet 40 imparts magnetism to the yoke 38 (attracting portion 39). A diaphragm spring 41 is interposed between the yoke 38 and the suction member 29. The diaphragm spring 41 urges the adsorbing member 29 (the diaphragm 24 and the piston 30) in the direction in which the suction member 29 is separated from the yoke 38 (on the four-wheel drive negative pressure chamber 23 side).

  The lock mechanism 14 has a function of locking the transmission blocking mechanism 13 at a position where the engagement between the slide gear 20 and the outer gear 21 is released. As shown in FIGS. 3 to 5, the lock mechanism 14 includes a fixed piece 42, an engagement protrusion 43, and an engagement groove 37. The fixed piece 42 is fitted in a groove portion 32 b formed on one end surface (the surface facing the lock mechanism 14) S of the fixed rivet 32 in the axial direction. The fixed piece 42 is a substantially flat plate-like member and extends outward in the radial direction with respect to the fixed rivet 32. The fixed piece 42 is rotatably provided on the fixed rivet 32 by a rotation shaft 44. The engaging protrusion 43 stands on one end side in the longitudinal direction of the fixed piece 42 in a direction (slide rivet 33 side) perpendicular to the longitudinal direction of the fixed piece 42.

  As shown in FIG. 5, three lock mechanisms 14 are provided at an axial end of the fixed rivet 32 at an angular interval of 120 degrees. Thus, by providing the lock mechanism 14 at predetermined intervals, the lock mechanism 14 can function stably. The number of the locking mechanisms 14 is not limited to three. For example, two locking mechanisms 14 may be provided at an angular interval of 180 degrees, or four at an angular interval of 90 degrees.

  The axial depth of the engagement groove 37 is shallower than the length of the expansion / contraction stroke of the rivet spring 34. Therefore, as will be described later, when the slide rivet 33 is slid in the axial direction (on the shaft 11 side with respect to the pressure receiving plate 29) with respect to the fixed rivet 32, the lock mechanism 14 is smoothly unlocked. be able to.

  Sealing members 44, 45, 46 are provided between the outer peripheral edge of the outer gear 21, between the hub 12 and the spindle 16, and between the shaft 11 and the spindle 16, thereby ensuring airtightness of the negative pressure chambers 22, 23. .

  In the power transmission device 10 configured as described above, when the two-wheel drive negative pressure chamber 22 is in a negative pressure state, the diaphragm 24 moves to the two-wheel drive negative pressure chamber 22 side, and the adsorption member 29 adsorbs the yoke 38. It will be in the state adsorbed by the part 39 (refer FIG. 3 and FIG. 4). Along with this, the engagement between the slide gear 20 and the outer gear 21 is released, and the two-wheel drive state in which the transmission of the rotational force between the shaft 11 and the hub 12 is interrupted is switched. When a predetermined time elapses after this switching, a timer provided in the two-wheel drive negative pressure path 25 is activated to open the two-wheel drive negative pressure chamber 22 to the atmosphere. The two-wheel drive state is maintained only by the attractive force of the yoke 38.

  In the two-wheel drive state, the rivet spring 34 is extended, and the standby state where the engagement protrusion 43 enters the engagement groove 37 is set. In this standby state, when an impact is applied to the vehicle 50 and the suction member 29 moves in a direction away from the yoke 38 (on the right side in FIG. 3), the fixed rivet 32 that fixes the suction member 29 is also moved to the suction member. 29 and try to move in the same direction. In this case, a rotational force in the direction of the arrow in FIG. 3 acts on the fixed piece 42 as the end of the fixed piece 42 opposite to the engagement protrusion 43 contacts the yoke 38. Due to this rotational force, the engagement protrusion 43 and the inner surface of the engagement groove 37 are strongly engaged, and the rotation of the fixed piece 42 by the rotational force is prevented. Further, the abutting state between the end of the fixed piece 42 opposite to the engaging protrusion 43 and the yoke 38 is maintained, and the adsorption member 29 is prevented from being detached from the yoke 38.

  On the other hand, when the four-wheel drive negative pressure chamber 23 is in a negative pressure state, the slide rivet 33 is against the fixed rivet 32 against the fixed rivet 32 against the urging force of the rivet spring 34 (the right side in FIG. 3). Move to. At this time, the rivet spring 34 is pushed and shrunk (shortened), and as shown in FIG. Along with this, the fixed piece 42 can be rotated around the rotation shaft 44.

  In this unlocked state, due to the negative pressure in the four-wheel drive negative pressure chamber 23, the diaphragm 24 moves to the four-wheel drive negative pressure chamber 23 side together with the fixed rivet 32 and the slide rivet 33. At this time, the other axial end portion (the end portion on the shaft 11 side) of the slide rivet 33 is an end portion facing the fixed rivet 32 (slide rivet 33, lock mechanism 14) of the shaft 11, as shown in FIG. It enters into the formed recess 11b. As the diaphragm 24 is moved, as shown in FIGS. 7 to 9, the fixed piece 42 rotates around the rotation shaft 44 so as to follow the inner peripheral edge 38a of the yoke 38 (the inner diameter surface of the suction portion 39). The slide gear 20 and the outer gear 21 are engaged with each other. Thereby, the four-wheel drive state in which the rotational force can be transmitted from the shaft 11 to the hub 12 is switched. When a predetermined time elapses after this switching, a timer provided in the four-wheel drive negative pressure path 27 is activated and the four-wheel drive negative pressure chamber 23 is opened to the atmosphere. The four-wheel drive state is maintained only by the urging force of the diaphragm spring 41.

  In this way, the two-wheel drive negative pressure chamber 22 and the four-wheel drive negative pressure chamber 23 are opened to the atmosphere together with the switching to the two-wheel drive state or the four-wheel drive state, and the deterioration of the sealing materials 44, 45, 46 and Inhalation of muddy water into the device due to negative pressure can be prevented.

  When the switching to the four-wheel drive state is completed, the end of the fixed piece 42 opposite to the end where the engagement protrusions 43 are formed contacts the inner diameter surface of the suction portion 39 of the yoke 38, and this fixed piece The rotation of 42 (clockwise rotation in FIG. 8) is prevented. At the same time, the pressing protrusion 47 of the fixed piece 42 presses the flange portion 33b formed on the slide rivet 33 toward the shaft 11 (right side in FIG. 8). By this pressing, the slide rivet 33 is prevented from returning to the original position by the urging force of the rivet spring 34.

  When the two-wheel drive negative pressure chamber 22 is brought into a negative pressure state in the four-wheel drive state, the slide rivet 33 slides with respect to the fixed rivet 32 toward the yoke 38 (left side in FIG. 8) due to the urging force of the rivet spring 34. Further, the diaphragm 24 moves to the two-wheel drive negative pressure chamber 22 side while indirectly pressing the fixed piece 42 to the yoke 38 side via the fixed rivet 32 and the slide rivet 33. The fixed piece 42 moves along the inner peripheral edge portion 38a of the yoke 38 (the inner diameter surface of the suction portion 39) and opens radially outward at the axial end portion of the yoke 38 by the pressing force from the flange portion 33b ( (See FIG. 4). At this time, the engagement protrusion 43 enters the engagement groove 37, and the standby state shown in FIG.

  The power transmission device 10 according to the above embodiment is merely an example, and can solve the problem of the present invention of stably maintaining the drive switching state (two-wheel drive state or four-wheel drive state) of the vehicle 50. Insofar as possible, the shape, arrangement, number, and the like of each component can be changed as appropriate.

1 Drive source (engine)
9 (9a) Wheel (front wheel)
11 Shaft 12 Hub 13 Transmission blocking mechanism 14 Lock mechanism 20 Slide gear 21 Outer gear 22 First negative pressure chamber (two-wheel drive negative pressure chamber)
23 Second negative pressure chamber (four-wheel drive negative pressure chamber)
24 Diaphragm 29 Adsorption member (pressure plate)
31 Rivet 32 Fixed rivet 33 Slide rivet 34 Rivet spring 37 Engagement groove 38 Yoke 41 Diaphragm spring 42 Fixed piece 43 Engagement protrusion c Center axis

Claims (4)

A shaft (11) disposed along the central axis and rotating around the axis by a driving force from a driving source (1);
A slide gear (20) integral with the shaft (11) and rotatable about an axis, and movable relative to the shaft (11) in the axial direction;
A hub (12) integrally provided with an outer gear (21) engageable with the slide gear (20) and rotating around the axis together with a wheel (9);
The slide gear (20) and the outer gear (21) are engaged by moving the slide gear (20) relative to the shaft (11) in the axial direction so that the shaft (11) and the hub are engaged. A transmission blocking mechanism (13) for disengaging the slide gear (20) and the outer gear (21) and blocking the rotation transmission, while enabling rotation transmission between (12) and
Either the position where the slide gear (20) and the outer gear (21) are engaged, or the position where the engagement between the slide gear (20) and the outer gear (21) is released is set to the transmission blocking mechanism (13). And a lock mechanism (14) that locks at that position. The transmission blocking mechanism (13)
A yoke (38) provided with magnetism;
A suction member (29) facing the yoke (38) in the axial direction, a rivet (31) holding the suction member (29) and moving the slide gear (20) in the axial direction;
Have
When the engagement between the slide gear (20) and the outer gear (21) is released, the yoke (38) is sandwiched between the lock mechanism (14) and the suction member (29), and The power according to claim 1, wherein the adsorption member (29) is adsorbed by the yoke (38) to prevent relative movement in the axial direction between the yoke (38) and the adsorption member (29). Transmission device. The rivet (31) is
A fixed rivet (32) holding the suction member (29);
A slide rivet (33) slidably inserted in the fixed rivet (32);
A rivet spring (34) interposed between the fixed rivet (32) and the slide rivet (33) and biasing the rivets (32, 33) in the opposite axial direction;
Have
The locking mechanism (14)
A fixed piece (42) rotatably provided on the fixed rivet (32);
An engaging protrusion (43) formed on the fixed piece (42);
An engagement groove (37) formed in the slide rivet (33) and engageable with the engagement protrusion (43);
Have
In the state where the rivet spring (34) is extended, the engagement protrusion (43) is engaged with the engagement groove (37),
The power transmission device according to claim 2, wherein the engagement protrusion (43) is retracted from the engagement groove (37) when the rivet spring (34) is shortened. The transmission blocking mechanism (13)
The internal space is divided into a first negative pressure chamber (22) that becomes negative pressure when the engagement between the slide gear (20) and the outer gear (21) is released, the slide gear (20), and the outer gear ( 21) a diaphragm (24) that is partitioned into a second negative pressure chamber (23), which becomes negative pressure when engaged with, and is held by the rivet (31);
A diaphragm spring (41) for biasing the diaphragm (24) toward the second negative pressure chamber (23);
The power transmission device according to claim 2 or 3, further comprising:

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