JP2008267562A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device with a cam groove on an end surface of an operation shaft formable large, and preventing wrong attachment between a small-diameter part and a large-diameter part, and allowing intermittent operation and a differential lock operation normally. <P>SOLUTION: This power transmission device is provided with: a differential means 10 capable of absorbing the difference in the rotation speed of a drive shaft by differential; an operation shaft 11 intermittently transmitting torque by connecting/disconnecting a propeller shaft 6 to/from a drive shaft to allow or to lock the differential of the differential means 10; and a drive means 12 capable of rotating the operation shaft 11. The power transmission device is constituted such that a fitting shape 11ab comprising a projecting shape formed on a small-diameter part 11a of the actuation shaft 11 and a fitting object shape 11bb comprising a recessed shape formed on a large-diameter part 11b are fitted and locked to each other, and the shapes are set asymmetrical with respect to lines passing through centers of end surfaces of the small-diameter part 11a and the large-diameter part 11b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power transmission device capable of switching between two-wheel drive and four-wheel drive of a vehicle and differentially locking or unlocking a differential means.

  For example, in a vehicle such as a four-wheel buggy or an ATV (All Terrain Vehicle), in general, the driving force from the engine is intermittently transmitted to the front wheels that are not driving wheels, and the power for switching between two-wheel driving and four-wheel driving is performed. Some have a transmission device (see, for example, Patent Document 1). This power transmission device is generally equipped with a differential means (differential gear) so that the difference between the rotational speeds of the left and right wheels can be absorbed by the differential to enable smooth turning. In addition, as for the differential means, what is mentioned in patent document 2 other than what consists of a differential gear is proposed.

  Furthermore, if either one of the left and right wheels of the vehicle slips on a road surface with a small coefficient of friction such as muddy, it becomes impossible to escape, or if the one wheel floats when turning, the driving torque decreases and the running performance deteriorates. Some have a mechanism for locking differential means to limit differential of one wheel (diff lock). Therefore, recently, a power transmission device has been proposed that can be switched by a motor so that the driving force can be intermittently engaged and the differential means can be locked.

  For example, as a conventional technique, an operating means is provided in a case constituting a casing of a power transmission device, and a fork is operated by operating the operating means by energizing a motor, and an input shaft connected to an engine; There is one that can intermittently connect the output shaft connected to the front wheel and operate another fork by continuing the operation to lock the differential means.

Specifically, such a conventional power transmission device operates an interposition member along a guide bar with a rotating plate that rotates by a driving force of a motor, and moves a fork accordingly, thereby The connected input shaft and the output shaft connected to the front wheel are intermittently connected, and the operation of the rotating plate is continued to operate another fork to lock the differential means.
JP 2003-191768 A Japanese National Patent Publication No. 6-509409

  However, in the above-described conventional power transmission device, the intermittent operation for intermittently connecting the input shaft connected to the engine and the output shaft connected to the front wheel and the differential lock operation for locking the differential means have a complicated configuration. Since it was performed, there was a problem that the manufacturing cost increased.

  Therefore, the present applicant has one operating shaft having cam grooves on the side surface and the end surface, respectively, and operates one fork in the cam groove on the side surface by rotating around the shaft of the operating shaft. Consider switching between the connected input shaft and the output shaft connected to the front wheel, and operating another fork in the cam groove on the end face to lock the differential means by further rotation. It came to do.

  However, when trying to increase the operating range of other forks by enlarging the cam groove on the end face, the entire operating shaft must have a large diameter, and support means such as a bearing that allows rotation around that axis is provided. Because there is a problem that it must be a large size, only the end surface where the cam groove on the end surface is formed is a separate (large diameter) part with a large diameter, and the cam groove is formed on the side. It was examined to make the (small diameter part) smaller in diameter than the large diameter part.

  However, for example, a convex shape having a two-surface width is formed on the end surface of the small diameter portion, and a concave shape corresponding to the convex shape is formed on the end surface of the large diameter portion (the surface opposite to the surface on which the cam groove is formed). If they are formed and matched and locked, the large diameter part is locked and integrated with the small diameter part, and both can be rotated together. Even if they are rotated 180 degrees from each other, they can be locked and integrated. In such a case, the phase of the cam groove on the side surface and the cam groove on the end surface are not matched, and there is a problem that the intermittent operation and the differential lock operation cannot be performed normally.

  The present invention has been made in view of such circumstances, and can make a cam groove on the end face of the operating shaft large, and can avoid erroneous assembly of the small diameter portion and the large diameter portion, and can perform intermittent operation and differential lock. An object of the present invention is to provide a power transmission device that can be operated normally.

  According to the first aspect of the present invention, there is provided an input shaft that is connected to a drive source of a vehicle and is driven to rotate around the shaft, and a right and left that can drive a front wheel or a rear wheel of the vehicle when the rotational force of the input shaft is transmitted A pair of output shafts, a differential means interposed between the input shaft and the output shaft and capable of absorbing a difference in rotational speed of the output shaft by differential, and the input shaft by rotation around the shaft. An operation shaft that can connect or release the rotational force of the input shaft to the output shaft by connecting to or releasing from the output shaft, and permitting or locking the differential of the differential means, and an arbitrary operation shaft A driving means capable of rotating; a case mounted on the vehicle while accommodating the differential means and the operating shaft; and switching between two-wheel driving and four-wheel driving of the vehicle by the operating shaft; and the differential means A power transmission device capable of performing a differential lock of A side cam groove capable of operating the first fork is formed on the side surface of the input shaft, and the first fork is operated along the side cam groove along with the rotation of the operation shaft to thereby connect the input shaft and the output shaft. An end face cam groove is formed on the end face of the operating shaft to enable the second fork to be connected or released, and the second fork is formed along the end face cam groove as the operating shaft rotates. The differential means is allowed or locked, and the operating shaft has a small-diameter portion formed with a side cam groove and a larger diameter than the small-diameter portion. A large-diameter portion formed with a cam groove, and a matching shape formed of a convex shape or a concave shape formed in the small-diameter portion and a matched shape formed of a concave shape or a convex shape formed in the large-diameter portion. Matched and locked, and the mated shape Beauty the matching shape, characterized in that it is asymmetrical shape with respect to a line passing through the center of the end surface of the small diameter portion and the large diameter portion.

  According to a second aspect of the present invention, in the power transmission device according to the first aspect, the mating shape and the mated shape have a shape having a two-surface width, and the center line is the center of the end surface in the small diameter portion and the large diameter portion. It is characterized by being offset from a line passing through.

  According to a third aspect of the present invention, in the power transmission device according to the first or second aspect, the small-diameter portion and the large-diameter portion are rotatably supported, so that the operating shaft is rotatable at both ends thereof. It is characterized by being supported.

  According to a fourth aspect of the present invention, in the power transmission device according to any one of the first to third aspects, a proximal end of the first fork is attached with the operating shaft interposed therebetween, and is guided by the operating shaft. It is characterized by operating.

  According to the first aspect of the present invention, the matching shape formed of the convex shape or the concave shape formed in the small diameter portion and the matched shape formed of the concave shape or the convex shape formed in the large diameter portion are matched and locked. In addition, since the mating shape and the mating shape are asymmetrical with respect to the line passing through the center of the end surface in the small diameter portion and the large diameter portion, the cam groove on the end surface of the operating shaft can be formed large. Thus, it is possible to avoid erroneous assembly of the small diameter portion and the large diameter portion, and to perform the intermittent operation and the differential lock operation normally.

  According to the invention of claim 2, the mated shape and the mated shape are formed with a shape having a two-surface width, and the center line is offset from a line passing through the center of the end surface in the small diameter portion and the large diameter portion. The mating shape and the mating shape can be easily formed with a general-purpose cutting tool while avoiding erroneous assembly of the small diameter portion and the large diameter portion.

  According to the invention of claim 3, since the small-diameter portion and the large-diameter portion are rotatably supported, the operating shaft is rotatably supported at both ends thereof. Strength can be improved and the structure can sufficiently withstand the load applied via the first fork and the second fork.

  According to the fourth aspect of the present invention, the proximal end of the first fork is attached with the operating shaft interposed therebetween, and operates while being guided by the operating shaft, so that the intermittent operation between the input shaft and the output shaft is reliably performed. In addition, since a separate guide means is not required, the number of parts can be reduced to improve the assembly workability, and the degree of freedom of layout in the case can be improved.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The power transmission device according to the present embodiment is mounted on a vehicle such as a four-wheel buggy or an ATV (All Terrain Vehicle), is switched between two-wheel drive and four-wheel drive, and a differential lock of a differential means or The lock can be released, and as shown in FIG. 1, it is disposed in front of the vehicle 1 and between the front wheels 2a and 2b.

  As shown in the figure, a propeller shaft 4 extends from the engine E (drive source) behind the vehicle 1 so that the rear wheels 3a and 3b can be rotationally driven via the drive shafts 5a and 5b. In addition, a propeller shaft 6 (input shaft) extends in front of the engine E and is connected to the power transmission device 7 according to the present embodiment. These propeller shafts 4 and 6 are connected to the engine E and are driven to rotate around an axis.

  Further, a pair of left and right drive shafts 8a and 8b (output shafts) are connected and extended from the left and right side surfaces b of the power transmission device 7, and when the rotational force of the propeller shaft 6 is transmitted, the vehicle 1 The front wheels 2a and 2b can be driven. That is, in the four-wheel drive state, the driving force of the engine E input to the power transmission device 7 is transmitted to the front wheels 2a and 2b via the drive shafts 8a and 8b. In addition, the front wheels 2a and 2b can also be rotationally driven. In the two-wheel drive state, as described later, the driving force of the engine E input to the power transmission device 7 is not transmitted to the drive shafts 8a and 8b, and the front wheels 2a and 2b are not driven wheels. Is done.

  As shown in FIGS. 2 and 3, the power transmission device 7 has a housing space inside the case 9 (first case 9 b and second case 9 a) having a left and right half shape, and has a housing space in the housing space. The drive member 13, the driven member 14, the differential means 10 (differential device), the operating shaft 11 and the like are accommodated. Specifically, the drive shaft 8a is extended from the side surface b of the first case 9b while the drive shaft 8a is extended from the side surface b of the second case 9a, and the drive shaft 8b extends from the side E of the first case 9b. A propeller shaft 6 extends from the rear surface a.

  The drive member 13 is rotatably supported by the bearing B1 and is connected to the propeller shaft 6 by spline fitting so that it can rotate around the axis L1 together with the drive member 13. The driven member 14 is rotatably supported by the bearings B2 and B3, and is connected to the driving member 13 by a sleeve A1 to be described later, and when the rotational force is transmitted, the driven member 14 can be rotated around the axis L1. It is a thing. A tooth surface 14 a constituting a gear is formed on the periphery of the driven member 14, and the tooth surface 14 a meshes with a tooth surface 15 a in the housing 15 of the differential means 10. Thereby, when the driven member 14 rotates, the rotational force is comprised so that the housing 15 can rotate via the tooth surfaces 14a and 15a.

  The differential means 10 is interposed between the propeller shaft 6 and the drive shafts 8a and 8b, and absorbs the difference in the rotational speed between the drive shafts 8a and 8b by the differential between the output cam members 10a and 10b. This is to make the turning of the vehicle smoothly. Specifically, a pair of output cams in which splines 10aa and 10ba for fitting the drive shafts 8a and 8b are formed in the housing 15 in the same manner as that disclosed in Patent Document 2 cited as the prior art. The members 10a and 10b are accommodated, and these output cam members 10a and 10b are rotatable relative to the housing 15 about the axis L2.

  Corrugated cam surfaces 10ab and 10bb are formed on the output cam members 10a and 10b, respectively. The cam surface 10ab is formed of, for example, an annular zigzag surface formed by seven pairs of mutually inclined helical surfaces, and the cam surface 10bb is also inclined, for example, by eight pairs corresponding to the cam surface 10ab. It is made of a helical surface. A plurality of cam followers 10c are disposed between the cam surfaces 10ab and 10bb. In the figure, symbol S1 indicates a leaf spring that presses the output cam member 10b toward the output cam member 10a.

  Thus, when the vehicle 1 travels straight, the cam follower 10c applies a load to the cam surfaces 10ab and 10bb to rotate the output cam members 10a and 10b together with the housing 15 and at the same time the vehicle 1 turns, the output cam Due to the difference in the number of cam surfaces 10ab and 10bb between the members 10a and 10b, a difference in rotational speed occurs between the output cam members 10a and 10b. That is, when the vehicle turns, the output cam members 10a and 10b make a rotational difference with respect to the housing 15, and the difference in rotational speed between the drive shafts 8a and 8b (speed difference between the inner ring and the outer ring in the front wheels 2a and 2b). Absorb.

  The operation shaft 11 is connected to or released from the propeller shaft 6 (input shaft) and the drive shafts 8a and 8b (output shaft) by rotation around the axis L3, so that the propeller shaft 6 is connected to the drive shafts 8a and 8b. The transmission of the rotational force is interrupted (intermittent operation) and the differential of the differential means 10 can be allowed or locked (diff lock operation). That is, the operating shaft 11 can perform the intermittent operation of the input shaft and the output shaft and the differential lock operation for the differential means 10 by the rotation around the axis L3.

  The operating shaft 11 includes a small-diameter portion 11a made of a small-diameter cylindrical member and a large-diameter portion 11b made of a large-diameter cylindrical member that is locked to one end of the small-diameter portion 11a. Is supported rotatably by a bearing B6, and the large-diameter portion 11b is rotatably supported by a bush B7. And when the drive means 12 mentioned later drives, both the small diameter part 11a and the large diameter part 11b are comprised so that it can rotate to the periphery of the axis | shaft L3. That is, both ends of the operating shaft 11 as a whole are rotatably supported by the bearing B6 and the bush B7.

  As shown in FIG. 6, a side cam groove 11aa capable of operating the first fork F1 is formed on the side surface of the operating shaft 11 (side surface of the small diameter portion 11a), and the side cam groove 11aa is formed in the side cam groove 11aa. The pin P2 is inserted. As shown in FIG. 7, the first fork F1 has an insertion hole F1a through which the operating shaft 11 (small-diameter portion 11a) can be inserted, and holds the operating shaft 11 on the base end side. In addition to being attached, a pin P2 is press-fitted and formed from the lower edge of the insertion hole F1a toward the side cam groove 11aa.

  As a result, when the operating shaft 11 rotates, the pin P2 moves along the side cam groove 11aa, and the first fork F1 is operated while being guided by the operating shaft 11 accordingly. The front end of the first fork F1 is locked to a sleeve A1 formed on the drive member 13 side. When the first fork F1 is operated, the sleeve A1 moves and the driven member 14 is moved as shown in FIG. The drive member 13 and the driven member 14 are connected to each other, and the propeller shaft 6 and the drive shafts 8a and 8b can be connected. In this state, the front wheels 2a and 2b of the vehicle become drive wheels and are switched to four-wheel drive.

  Thereafter, when the operating shaft 11 rotates in the opposite direction, the pin P2 moves in the reverse direction along the side cam groove 11aa, and accordingly, the first fork F1 returns to the initial position while being guided by the operating shaft 11. As shown in FIG. 2, the sleeve A1 is moved to the original position so that the connection between the drive member 13 and the driven member 14 is released. Therefore, the vehicle is switched from four-wheel drive to two-wheel drive.

  On the other hand, as shown in FIG. 8, an end face cam groove 11ba capable of operating the second fork F2 is formed in the large diameter portion 11b of the operating shaft 11, and the end face cam groove 11ba is formed in the end face cam groove 11ba. The pin P3 is inserted. As shown in FIG. 9, the second fork F2 is provided with a pin P3 on its proximal end side and engages the sleeve A2 on the distal end side, and extends on the extension line (axis L3) of the operating shaft 11. It is installed.

  As a result, when the operating shaft 11 rotates, the pin P3 moves along the end face cam groove 11ba, and the second fork F2 is actuated to move the sleeve A2 upward in FIG. . The end face cam groove 11ba is set to operate the second fork F2 after the first fork F1 is operated and the propeller shaft 6 is connected to the drive shafts 8a and 8b as the operating shaft 11 rotates. Yes.

  As shown in FIG. 10, the sleeve A2 has a plurality of (three in the present embodiment) pins P1 integrally formed to project, and when the second fork F2 is actuated, as shown in FIG. The pin P1 is inserted through the fitting hole 10ac of the output cam member 10a. When the pin P1 is inserted into the output cam member 10a, the output cam member 10a and the housing 15 are connected, and the differential of the differential means 10 is locked (diff-locked).

  Thereafter, when the operating shaft 11 rotates in the opposite direction, the pin P3 moves in the opposite direction along the end face cam groove 11ba, and accordingly, the second fork F2 returns to the initial position, so as shown in FIG. A2 moves to the original position, and the pin P1 is separated from the fitting hole 10ac of the output cam member 10a, and the differential of the differential means 10 is allowed (that is, the differential lock is released).

  Here, as shown in FIGS. 11 and 12, the operating shaft 11 according to the present embodiment has a matching shape 11ab and a matching shape 11bb formed on the connecting end surface of the small diameter portion 11a and the large diameter portion 11b, respectively. . As shown in FIG. 11, the matching shape 11ab has a shape having a two-surface width (11ac), and its center line n is offset by a predetermined dimension from a line m passing through the center of the end surface of the small diameter portion 11a.

  On the other hand, as shown in FIG. 12, the matched shape 11bb has a shape having a two-surface width (11bc), and its center line p is an end surface of the large-diameter portion 11b (the surface on which the end surface cam groove 11ba is formed). A predetermined dimension is offset from a line o passing through the center of the opposite surface. The matched shape 11ab and the matched shape 11bb have sizes and shapes corresponding to each other, and when the matched shape 11ab (convex shape) is fitted into the matched shape 11bb (concave shape), the small diameter portion 11a and the large-diameter portion 11b are locked in the rotation direction so as to be integrally rotatable.

  However, the two-surface width refers to two parallel surfaces separated by a predetermined dimension, and the mated shape 11bb (concave shape) is slightly larger than the matched shape 11ab (convex shape) in order to perform fitting. Has been. In this embodiment, a matching shape 11ab made of a convex shape is formed on the small diameter portion 11a, and a matched shape 11bb made of a concave shape is formed on the large diameter portion 11b. It is good also as conformity shape which consists of concave shape in the part 11a, and to-be-matched shape which consists of convex shape in the large diameter part 11b.

  Then, if the mating shape 11ab and the mated shape 11bb are matched and locked in the rotation direction, when the driving means 12 is driven, the large-diameter portion 11a and the small-diameter portion 11b rotate as one body, If the pin P2 moves along the cam groove 11aa, and the first fork F1 is operated while being guided by the operating shaft 11, and then further rotates together, the pin P3 moves along the end face cam groove 11ba. Accordingly, the second fork F2 is activated.

  As shown in FIG. 3, the driving means 12 is mainly configured by a motor M, a gear group including a worm gear G <b> 1 and a gear G <b> 2, a spring S, a rotating shaft member 16, and a rotating member 18. . The motor M rotates the output shaft Ma when energized, and can be rotated forward and backward. The worm gear G <b> 1 is connected to the output shaft Ma and can be rotated as the motor M is driven.

  The gear G2 has a large-diameter gear G2a and a small-diameter gear G2b. The large-diameter gear G2a meshes with the worm gear G1, and the small-diameter gear G2b meshes with a tooth surface formed on the periphery of the rotating member 18. It is configured. The rotating member 18 accommodates the spring S in the circumferential direction thereof, and is rotatable about the axis L3 together with the spring S in conjunction with the rotation of the gear G2.

  The rotary shaft member 16 is formed through the central portion of the rotary member 18 and is rotatable around the shaft L3. The connecting member 17 is fixed to the end surface of the rotary shaft member 16. . A bending portion 17 a extends from the connecting member 17, and the bending portion 17 a is in contact with the end of the spring S. Thereby, when the rotating member 18 rotates, the rotational force is transmitted to the connecting member 17 via the spring S, and the rotating shaft member 16 can be rotated.

  One end of the operation shaft 11 described above is locked to the rotation shaft member 16, and the operation shaft 11 can be arbitrarily rotated by the rotational drive of the motor M. That is, when the motor M is rotationally driven, the rotational force is transmitted to the worm gear G 1, the gear G 2, the rotating member 18, the spring S, the connecting member 17 and the rotating shaft member 16, and the operating shaft locked to the rotating shaft member 16. 11 is rotated.

  The driving means 12 is disposed on the back surface a of the case 9 (the surface facing the engine E). This eliminates the need to provide a motor or the like on the left and right side surfaces b of the case 9 in the power transmission device 7, thereby avoiding interference with a suspension device (not shown) such as a tie rod in the vehicle 1, and its movable range. The degree of freedom can be improved.

Next, the operation of the power transmission device 7 according to this embodiment will be described.
First, in order to switch the vehicle from two-wheel drive to four-wheel drive, the motor M is driven to rotate the operating shaft 11 (small diameter portion 11a and large diameter portion 11b) around the axis L3. Thus, the first fork F1 is operated by sliding on the peripheral surface of the small diameter portion 11a while being guided by the operating shaft 11, and the sleeve A1 is fitted to the spline of the driven member 14. When the spline shape of the sleeve A1 and the spline corresponding to the driven member 14 do not coincide with each other, the spring S contracts to rotate the driving means 12 side (specifically, the rotating member 18). Absorbs.

  Thus, the rotation of the operating shaft 11 can be stopped until the sleeve A1 is spline-fitted while the motor M is continuously driven. When the spline shape of the sleeve A1 matches the spline on the driven member 14 side corresponding to the sleeve A1, the spring S expands and the sleeve A1 moves to the specified position, and the driven member 14 and the spline fit. . Thus, the driving force of the engine E is transmitted to the rear wheels 3a, 3b and the front wheels 2a, 2b by connecting the driving member 13 and the driven member 14 and connecting the propeller shaft 6 and the drive shafts 8a, 8b. To get.

  In the above operation process, the pin P3 is inserted through the arcuate portion of the end face cam groove 11ba, and the second fork F2 does not operate. In order to lock the differential of the differential means 10 from that state (diff lock), the motor M is further rotated, and the operating shaft 11 (small diameter portion 11a and large diameter portion 11b) is rotated around the axis L3. Accordingly, the second fork F2 operates along the end face cam groove 11ba of the large diameter portion 11b, so that the sleeve A2 moves upward in FIG. 2, and the pin P1 is inserted into the fitting hole 10ac of the output cam member 10a. . When the pin P1 of the sleeve A2 and the fitting hole 10ac do not match, the spring S contracts to absorb the rotation of the driving means 12 (specifically, the rotating member 18).

  Thus, the rotation of the operating shaft 11 can be stopped until the sleeve A2 is spline-fitted while the motor M is continuously driven. When the pin P1 of the sleeve A2 and the fitting hole 10ac are matched, the spring S2 is extended and the sleeve A2 is moved to a specified position, and the pin P1 is inserted into the fitting hole 10ac. As a result, the output cam member 10a and the housing 15 are connected, and the differential of the differential means 10 is locked (diff-locked).

  If the motor M is rotationally driven in the opposite direction, the operating shaft 11 can be rotated in the opposite direction around the axis L3, and the differential allowance (release of the diff lock) of the operating means 10 and the propeller can be performed. The connection between the shaft 6 and the drive shafts 8a and 8b can be sequentially released. Thus, according to the power transmission device 7 according to the present embodiment, the operation shaft 11 can arbitrarily switch between the two-wheel drive and the four-wheel drive of the vehicle 1 and the differential lock (diff lock) of the differential means 10. Can be done.

  According to the present embodiment, the matched shape 11ab and the matched shape 11bb are formed of shapes having a two-surface width, and the center line is offset from a line passing through the center of the end surface in the small diameter portion and the large diameter portion. The matching shape and matched shape can be easily formed with a general-purpose cutting tool while avoiding erroneous assembly of the small diameter portion 11a and the large diameter portion 11b. That is, when the small-diameter portion 11a and the large-diameter portion 11b are mistakenly assembled from the prescribed state (the same is true for the state rotated by 180 degrees), the axes of the small-diameter portion 11a and the large-diameter portion 11b are aligned. In the matched state, the matched shape 11ab and the matched shape 11bb do not match, and erroneous assembly can be prevented.

  As described above, the matched shape 11ab and the matched shape 11bb have a shape having two widths, and the matched shape and the matched shape are lines passing through the centers of the end surfaces (connection end surfaces) of the small diameter portion 11a and the large diameter portion 11b. On the other hand, an asymmetric shape is sufficient. As described above, according to the mated shape and the mated shape that are asymmetrical with respect to the line passing through the center of the end surface (connection end surface), it is possible to avoid erroneous assembly of the small-diameter portion 11a and the large-diameter portion 11b. The operation can be performed normally.

  The operating shaft 11 according to the present embodiment includes a small-diameter portion 11a having a side cam groove 11aa and a large-diameter portion 11b having a larger diameter than the small-diameter portion 11a and having an end-surface cam groove 11ba. Since the small diameter portion 11a and the large diameter portion 11b are rotatably supported, the small diameter portion 11a can be easily supported and the large diameter portion 11b has a large end face cam groove 11ba. And the operating range of the second fork F2 can be set large.

  That is, the smaller the diameter of the operating shaft 11 is, the more advantageous it is to support by the bearing. However, if the end surface is small, the end surface cam groove 11ba cannot be formed large, and the operating range of the second fork F2 is reduced. There is a possibility that the differential means 10 cannot be allowed or locked more accurately. On the other hand, according to the present embodiment, the small-diameter portion 11a in which the side cam groove 11aa is formed (the operating range of the first fork F1 depends on the longitudinal dimension of the small-diameter portion 11a, so the diameter can be small). By setting only the large diameter portion 11b in which the end face cam groove 11ba is formed to have a large diameter, the operating range of the second fork F2 can be set large.

  Further, according to the present embodiment, the small-diameter portion 11a and the large-diameter portion 11b are rotatably supported, so that the entire operating shaft 11 is rotatably supported at both ends thereof. Compared to the above, the strength is improved, and the structure can sufficiently withstand the load applied through the first fork F1 and the second fork F2. In particular, in this embodiment, when the spline shape of the sleeve A1 and the spline corresponding to the driven member 14 do not match (when the spring S is contracted), a large load is applied to the side cam groove 11aa. However, since the operating shaft 11 is supported at both ends, it can sufficiently withstand such a load.

  Further, the base end of the first fork F1 is attached with the operating shaft 11 interposed therebetween, and operates while being guided by the operating shaft 11, so that the propeller shaft 6 (input shaft) and the drive shafts 8a and 8b (output shaft) Since the intermittent operation can be reliably performed and a separate guiding means is not required, the number of parts can be reduced to improve the assembling workability, and the degree of freedom of the layout in the case 9 can be improved. it can.

  Furthermore, according to the present embodiment, the side surface and the end surface of the operating shaft 11 are formed with the side surface cam groove 11aa and the end surface cam groove 11ba that can operate the first forks F1 and F2, respectively. As the shaft 11 rotates, the first forks F1 and F2 are operated along the side surface cam groove 11aa and the end surface cam groove 11ba to connect or release the propeller shaft 6 and the drive shafts 8a and 8b. Since the differential permitting or locking of the means 10 is performed, the driving means 12 can be surely switched between two-wheel driving and four-wheel driving, and the differential means 10 can be locked or released.

  Although the present embodiment has been described above, the present invention is not limited to this, and may be applied to other vehicles such as automobiles. When applied to other vehicles, the driving force of the engine may be transmitted to the front wheels at all times, and transmission to the rear wheels may be intermittently performed so that switching between two-wheel drive and four-wheel drive is possible. Further, the differential means 10 in the present embodiment has a pair of output cam members housed in the housing, but instead of this, a general-purpose differential means using a planetary gear or the like. It is good.

  The operating shaft is composed of a small-diameter portion in which the side cam groove is formed and a large-diameter portion having a larger diameter than the small-diameter portion, and the end-surface cam groove is formed, and a convex shape formed in the small-diameter portion or The mated shape consisting of a concave shape and the concave shape formed on the large-diameter portion or the mated shape consisting of a convex shape are matched and locked, and the mated shape and the mated shape are small and large diameter portions. As long as the power transmission device has an asymmetrical shape with respect to a line passing through the center of the end face, a device having a different external shape or the like, or a device to which other functions are added can be applied.

The schematic diagram which shows the vehicle with which the power transmission device which concerns on embodiment of this invention is applied. Whole sectional view showing the power transmission device Schematic diagram showing the internal configuration of the drive means in the same power transmission device Whole sectional view showing the power transmission device (switched to four-wheel drive) Whole sectional view showing the same power transmission device (in a state where the differential of the differential means is locked) Exploded view of the operating shaft showing the side cam groove in the power transmission device Schematic showing a fork that operates along the side cam groove in the same power transmission device End view of operating shaft showing cam groove for end face in the power transmission device Schematic showing a fork that operates along an end face cam groove in the power transmission device Schematic diagram showing a sleeve that engages with a fork that operates along the cam groove for the end face. It is a schematic diagram which shows the small diameter part and large diameter part which comprise the operating shaft in the same power transmission device, Comprising: The perspective view which shows the matching shape formed in the small diameter part It is a schematic diagram which shows the small diameter part and large diameter part which comprise the operating shaft in the same power transmission device, Comprising: The perspective view which shows the to-be-matched shape formed in the large diameter part

Explanation of symbols

1 Vehicle 2a, 2b Front wheel 3a, 3b Rear wheel 4 Propeller shaft 5a, 5b Drive shaft 6 Propeller shaft (input shaft)
7 Power transmission device 8a, 8b Drive shaft 9 Case 9a Second case 9b First case 10 Differential means 11 Actuating shaft 11aa Side cam groove 11ab Matching shape 11ba End face cam groove 11bb Matched shape 12 Driving means 13 Driving member 14 Follower member 15 Housing 16 Rotating shaft member 17 Connecting member 18 Rotating member M Motor F1 First fork F2 Second fork A1, A2 Sleeve a Back of case b Side of case

Claims (4)

An input shaft connected to a vehicle drive source and driven to rotate about the shaft;
When the rotational force of the input shaft is transmitted, a pair of left and right output shafts that can drive the front wheels or rear wheels of the vehicle,
Differential means interposed between the input shaft and the output shaft and capable of absorbing the difference in the rotational speed of the output shaft by differential;
The rotation around the shaft causes the input shaft and the output shaft to be connected to each other or released so that the transmission of the rotational force of the input shaft to the output shaft is interrupted, and the differential of the differential means is allowed or locked. An operating shaft to obtain,
Drive means capable of arbitrarily rotating the operating shaft;
A case mounted on the vehicle while accommodating the differential means and the operating shaft;
A power transmission device capable of switching between two-wheel drive and four-wheel drive of the vehicle and differentially locking the differential means by the operating shaft,
A side cam groove capable of operating the first fork is formed on a side surface of the operating shaft, and the first fork is operated along the side cam groove along with the rotation of the operating shaft to output the input shaft and the output shaft. An end face cam groove capable of operating the second fork is formed on the end surface of the operating shaft while being connected to or released from the shaft, and along the end surface cam groove as the operating shaft rotates. Actuating a second fork to permit or lock the differential means; and
The operating shaft is composed of a small diameter portion in which the side cam groove is formed and a large diameter portion in which the end surface cam groove is formed, and is formed in the small diameter portion. The mating shape consisting of a convex shape or a concave shape and the mating shape consisting of a concave shape or a convex shape formed on the large-diameter portion are matched and locked. A power transmission device having an asymmetric shape with respect to a line passing through a center of an end face in a large diameter portion.   2. The matched shape and the matched shape are formed of a shape having a two-sided width, and a center line thereof is offset from a line passing through a center of an end face in the small diameter portion and the large diameter portion. Power transmission device.   The power transmission device according to claim 1 or 2, wherein the small-diameter portion and the large-diameter portion are rotatably supported, whereby the operating shaft is rotatably supported at both ends thereof.   The power transmission device according to any one of claims 1 to 3, wherein a base end of the first fork is attached with the operation shaft interposed therebetween and operates while being guided by the operation shaft.

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