JP2005076865A - Differential device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque transmission capacity sufficient for a disconnecting means while avoiding the increase in size, weight and cost in a differential device provided with the interrupting means for drive force on an output member of a differential mechanism. <P>SOLUTION: The differential device comprises a differential mechanism 5 in which one output side gear 33 is composed of two division members 39, 41, and a claw clutch 7 which interrupts the drive force between the division members 39, 41. This claw clutch 7 is provided on a clutch ring 55 of the claw clutch 7 and an opposite part in the axial direction of the division member 39. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a differential apparatus having a driving force intermittent function.

  Patent Document 1 describes a differential device 501 as shown in FIG.

  This differential device 501 is used in a wheel-side power transmission system that is disconnected when a four-wheel drive vehicle is driven by two-wheel drive. A differential case 503, a bevel gear type differential mechanism 505, a meshing clutch 507, a return spring 509, an actuator 511, a pressing member 513, and the like.

  The differential mechanism 505 includes a plurality of pinion shafts 515 connected to the differential case 503, a pinion gear 517 supported on the pinion shaft 515, and output side gears 519 and 521 meshed with these pinion gears 517. ing. The left side gear 519 is divided into a gear member 523 meshed with the pinion gear 517 and a boss member 525, and the meshing clutch 507 is arranged so as to intermittently connect the gear member 523 and the boss member 525. ing. The gear member 523 is connected to the left wheel side via the meshing clutch 507, the boss member 525, and the axle, and the right side gear 521 is connected to the right wheel side via the axle.

  A clutch ring 531 is movably connected to a gear portion 529 formed on the outer periphery of the flange portion 527 of the boss member 525, and the meshing clutch 507 is connected to the gear portion 533 formed on the outer periphery of the gear member 523 and the clutch ring 531. Between.

  The return spring 509 presses the clutch ring 531 in the connecting direction of the meshing clutch 507 (right side in FIG. 4), and the actuator 511 causes the clutch ring 531 to move leftward via the pressing member 513 while bending the return spring 509. Press to release the engagement of the meshing clutch 507.

  The driving force of the engine rotates the differential case 503, and the rotation of the differential case 503 is distributed from the pinion shaft 515 to the gear member 523 and the side gear 521 via the pinion gear 517.

  At this time, if the meshing clutch 507 is connected, the driving force is transmitted to the left wheel side via the gear member 523, the meshing clutch 507 and the boss member 525, and from the right side gear 521 to the right wheel side. Is transmitted to the four-wheel drive state.

Further, when the engagement clutch 507 is released, the differential mechanism 505 is idled while the gear member 523 is idling, so that the driving force transmission to the wheel side is cut off and the vehicle is driven by two wheels. It becomes a state.
FIG. 1 of JP2003-42263A

  In the differential device that has a driving force intermittent function (intermittent means) as described above and is used for a four-wheel drive vehicle, the differential case is composed of an outer differential case and an inner differential case accommodated therein, and the intermittent means is defined by these differential cases. Are provided between the outer differential case and the inner differential case. Thus, the differential device having a differential case with a double structure has a large size (large diameter) and a large weight, and there is a risk that the in-vehicle performance may be lowered. Further, since the differential mechanism has a smaller diameter corresponding to the thickness of the inner differential case, and the pinion gear also has a smaller diameter and the torque transmission capacity decreases, it is necessary to further increase the number of pinion gears, leading to an increase in cost.

  Therefore, the above-described differential device 501 solves the above-described problems associated with the use of the inner differential case by configuring the driving force to be intermittent between the two side gears 519.

  However, in the case of the differential device 501, the gear portion 533 constituting the meshing clutch 507 is provided on the outer periphery of the gear member 523, and the clutch ring 531 is formed on the outer periphery of the boss member 525 (flange portion 527). Therefore, in order to give a sufficient torque capacity (strength) to these gear portions 533 and 529, the respective tooth widths (axial dimensions) must be increased, and the differential device 501 can be axially increased accordingly. There is a risk that the size will increase and the in-vehicle performance will decrease.

  Further, when transmission torque or differential torque is applied to the meshing clutch 507, the clutch ring 531 is difficult to come off due to frictional resistance between the gear portion 533 and the clutch ring 531, and the four-wheel drive state is changed to the two-wheel drive state. There is a risk that the switching response will be reduced.

  In order to improve this, it is necessary to increase the size of the actuator 511 and strengthen the return spring 509, and the differential device 501 becomes larger and heavier, and the cost increases.

  Accordingly, the present invention provides a sufficient torque transmission capacity to the intermittent means while avoiding an increase in size, weight, and cost in a differential device in which an intermittent means for driving force is provided on the output member of the differential mechanism. It is an object.

  The invention of claim 1 includes a differential case that rotates in response to a driving force from a prime mover, a differential mechanism that distributes the rotation of the differential case from a pair of output members to each wheel side, and a driving force intermittent means. One of the output members is constituted by two divided members, and the intermittent means is a differential device configured to intermittently connect these divided members, and the intermittent means is defined as the divided member. It is characterized in that it is provided in the axially opposite portion.

  The invention of claim 2 is the differential apparatus according to claim 1, wherein the differential mechanism includes a pinion shaft connected to the differential case, a pinion gear supported on the pinion shaft, and the pinion A bevel gear type differential mechanism comprising a pair of side gears that are the pair of output members respectively meshed with a gear, one of the side gears is a gear member meshed with the pinion gear, and a boss member connected to the wheel side And the intermittent means is a meshing clutch provided at an axially opposed portion of the gear member and a clutch member connected to the boss member so as to be axially movable.

  In the differential device according to the first aspect, since the intermittent means for driving force is provided in the axially facing portion of the dividing member, unlike the conventional example in which the intermittent means is provided on the outer periphery of the dividing member, the axially facing portion of the dividing member is wide. By using the surface, it is possible to increase the size of the intermittent means (for example, if the intermittent means is a meshing clutch, the gear width of the gear portion) and provide sufficient torque transmission capacity (strength).

  Therefore, it is not necessary to increase the tooth width of the gear portion in the axial direction in order to improve the torque transmission capacity, and the accompanying increase in the size of the differential device and the reduction in in-vehicle performance are prevented.

  Moreover, in the structure of this invention which provides an interruption means in the axial direction opposing part of a division member, a gear part can be moved to an axial direction and an interruption means can be operated. Therefore, for example, if a cam angle that promotes disengagement is applied to the gear portion, the disengagement of the intermittent means is promoted by the cam thrust force generated by receiving differential torque or transmission torque. The response when switching from the two-wheel drive state to the two-wheel drive state is improved, the actuator for operating the intermittent means is enlarged, the return spring need not be strengthened, and the differential device is increased in size, weight, and in-vehicle performance. Reduction and cost increase can be avoided.

  The differential apparatus according to the second aspect can obtain the same effects as those of the first aspect.

Example 1
The front differential 1 (the differential device of the first embodiment) will be described with reference to FIGS. The left and right directions are the four-wheel drive vehicle using the front differential 1 and the left and right directions in FIGS. 1 and 2, and members and the like that are not given reference numerals are not shown.

[Features of front differential 1]
The front differential 1 includes a differential case 3 that rotates by receiving driving force from the prime mover,
A differential mechanism 5 for distributing the rotation of the differential case 3 from the pair of output members to the respective wheel sides;
A meshing clutch 7 (interrupting means) for intermittently driving force,
In the configuration in which one of the output members is divided into two divided members, and the meshing clutch 7 intermittently connects these divided members.
The differential mechanism 5 includes a pinion shaft 27 connected to the differential case 3, a pinion gear 29 supported on the pinion shaft 27, and the side gears 31 and 33 which are the pair of output members respectively engaged with the pinion gear 29. Become
The side gear 33 which is one of the output members is divided into a gear member 39 meshed with the pinion gear 29 and a boss member 41 connected to the wheel side,
By providing the meshing clutch 7 at the axially facing portion between the gear member 39 and the clutch ring 55 (clutch member) connected to the boss member 41 so as to be axially movable,
As described above, the tooth width of the meshing clutch 7 can be widened to give a sufficient torque transmission capacity (strength), and the front differential 1 can be prevented from being enlarged and the vehicle-mounted performance can be reduced by expanding the tooth width in the axial direction. doing.

  In addition, by providing a cam angle to the meshing clutch 7 to promote connection release, the switching response from the four-wheel drive state to the two-wheel drive state is improved, and the actuator 11 is not enlarged and the return spring 9 is not required to be strengthened. Thus, an increase in the size, weight, in-vehicle performance, and cost of the front differential 1 are prevented.

[Configuration of power transmission system for four-wheel drive vehicles]
The front differential 1 (a differential device that distributes the driving force of the engine to the left and right front wheels) is used in a front wheel side power transmission system of a four-wheel drive vehicle. It is comprised so that a driving force may be cut | disconnected.

  The power transmission system of this four-wheel drive vehicle includes an engine (motor), transmission, transfer, 2-4 switching mechanism, front wheel side propeller shaft, front differential 1, front axle, left and right front wheels, rear wheel side propeller shaft, It consists of a rear differential (a differential device that distributes the driving force of the engine to the left and right rear wheels), a rear axle, and left and right rear wheels.

  The driving force of the engine is transmitted from the transmission to the transfer, and is distributed from the transfer to the front wheel side and the rear wheel side. The driving force distributed to the rear wheel side is transmitted from the rear wheel side propeller shaft to the rear differential, and is distributed from the rear differential to the left and right rear wheels via the rear axle.

  The driving force distributed to the front wheels is changed from the 2-4 switching mechanism, the front wheel side propeller shaft, and the front differential 1 to the front axle while the 2-4 switching mechanism and the front differential 1 (meshing clutch 7) are connected. And the vehicle is in a four-wheel drive state. Further, when the connection between the 2-4 switching mechanism and the front differential 1 (meshing clutch 7) is released, the front wheel side is disconnected from the engine, and the vehicle enters the two-wheel drive state of the rear wheel drive. As described above, the 2-4 switching mechanism constitutes the front wheel side output interface of the transfer, and the connection release operation and the connection operation are performed in conjunction with the front differential 1 (meshing clutch 7), so that the driving force to the front wheel side is increased. Intermittently.

[Configuration of front differential 1]
The front differential 1 includes a differential case 3, a bevel gear type differential mechanism 5, a meshing clutch 7 (intermittent means), a return spring 9, a gear plate actuator 11, and the like. The front differential 1 is disposed inside the transfer case 13, and an oil sump is formed in the transfer case 13.

  The differential case 3 is configured by fixing a casing body 15 and a cover 17 with bolts 19. A boss portion 21 of the casing body 15 is supported on the transfer case 13 via a thrust bearing 23, and a boss portion 25 of the cover 17 is It is supported on the transfer case 13 via a thrust bearing.

  A ring gear is bolted to the casing body 15 and the cover 17. The ring gear meshes with the drive pinion gear, and the drive pinion gear is formed integrally with the drive pinion shaft. The drive pinion shaft is connected to a transfer 2-4 switching mechanism via a joint, a front wheel side propeller shaft, and the like, and the driving force of the engine is transmitted from the transfer and 2-4 switching mechanism via the front wheel side power transmission system. The differential case 3 is rotated.

  The differential mechanism 5 includes three pinion shafts 27, a pinion gear 29 rotatably supported on each pinion shaft 27, and left and right output side gears 31 and 33 (a pair of output members) meshed with the pinion gear 29. It is configured. Each pinion shaft 27 is engaged with the through hole 35 of the differential case 3 at its tip and is prevented from coming off by a spring pin 37.

  The right side gear 33 is divided into a gear member 39 meshed with the pinion gear 29 and a boss member 41 connected to the right front axle. The gear member 39 is supported on the outer periphery of the boss member 41 so as to be relatively rotatable. Yes. As described below, the meshing clutch 7 is disposed so as to intermittently connect the gear member 39 and the boss member 41. A left front axle is splined to the boss portion 43 of the left side gear 31, and a right front axle is splined to the boss member 41. The left side gear 31 is connected to the left front wheel via the left front axle. The gear member 39 (right side gear 33) is connected to the right front wheel side via the meshing clutch 7, the boss member 41, and the right front axle.

  The boss portion 43 of the left side gear 31 is supported by a support portion 45 formed on the cover 17, and the boss member 41 of the right side gear 33 is supported by a support portion 47 formed on the casing body 15. A thrust washer 49 is disposed between the side gear 31 and the cover 17 to receive the meshing thrust force of the side gear 31. A thrust washer 51 is disposed between the gear member 39 and the boss member 41, and the boss member 41. A thrust washer 51 is disposed between the clutch ring 55 of the meshing clutch 7 and receives a meshing thrust force of the side gear 33 (gear member 39).

  A spherical washer 53 is disposed on the inner periphery of the casing body 15 so as to face each pinion gear 29, and the meshing force received by the pinion gear 29 due to the meshing between the centrifugal force of the pinion gear 29 and each side gear 31, 33. Bears the power.

  The meshing clutch 7 has meshing teeth 57 formed on the left side surface (axially facing portion) of the clutch ring 55 and a right side surface (axially facing portion) located on the back side of the tooth bottom of the gear member 39 of the side gear 33. It is comprised with the meshing tooth 59 formed. The clutch ring 55 is disposed so as to be movable in the axial direction by meshing portions 61 and 63 provided between the outer periphery of the boss member 41 of the side gear 33.

  Further, when the meshing teeth 57, 59 of the clutch are engaged with each of the meshing portions 61, 63, a cam angle is generated by receiving a torque from the meshing teeth 57, 59 and generating a cam thrust force, thereby promoting the meshing of the meshing clutch 7. Is given in both forward and reverse rotation directions. The cam angle may be zero degrees. In this case, the holding of the clutch 7 depends on the driving rotational torque caused by the engagement of the clutch 7 itself and the axial movement restriction caused by the axial pressing force of the actuator 11.

  The return spring 9 is a coil spring, and is disposed between the gear member 39 and the clutch ring 55 via the retainer 65, and engages the clutch ring and urges the clutch 7 in the direction of releasing the connection (right direction). The retainer 65 is engaged with the meshing portion 61 of the clutch ring 55 and is prevented from rotating.

  Further, the casing body 15 is provided with a plurality of openings 67 at equal intervals in the circumferential direction, and the same number of pressing members 69 engage with these openings 67 and protrude outward.

  As will be described below, when the clutch ring 55 is moved to the left and right by the gear plate actuator 11 and moved to the left, the meshing clutch 7 is meshed as shown in FIG. 2, and the gear member 39 and the boss member of the side gear 33 are engaged. 41 is connected and returned to the right, the meshing clutch 7 is disengaged as shown in FIG. 1, and the gear member 39 and the boss member 41 are separated. The pressing member 69 of the actuator 11 and the meshing portions 57 and 59 of the clutch 7 are arranged on substantially the same circumference so that the moving operation force of the actuator 11 presses the meshing portions 57 and 59 linearly in the axial direction of the pressing member 69. Function. Therefore, useless bending force does not act on each member related to clutch engagement from pressing.

  The gear plate actuator 11 includes a gear plate 71, a shift spring, a cam, an electric motor 73, and the like. The shift spring has a stronger urging force than the return spring 9 described above, and while the cam is not operating, the return spring 9 is bent to move the clutch ring 55 to the left to connect the meshing clutch 7. The electric motor 73 rotates the gear plate 71 in one direction and the other direction by meshing the pinion gear 75 and the gear plate 71, and the cam operates when the electric motor 73 rotates in one direction, and the cam rotates when the electric motor 73 rotates in the other direction. Stops operating. When the cam is operated, the shift spring is bent by the cam thrust force. When the shift spring is bent, the clutch ring 55 is returned to the right by the return spring 9 and the engagement of the clutch 7 is released.

  In addition to the opening 67 of the casing body 15, the differential case 3 is provided with a plurality of openings 77 in the cover 17. The casing body 15 and the cover 17 are formed with helical oil grooves on the inner circumferences of the boss portions 21 and 25, and oil passages 79 and 81 communicating with these. The oil in the oil reservoir formed in the transfer case flows into and out of the differential case 3 from these openings 77, spiral oil grooves, and oil passages 79 and 81 as the front differential 1 rotates, and the gears 29, 31, and 33 (gears) Meshing portion of member 39), sliding portion of pinion shaft 27 and pinion gear 29, meshing clutch 7 (meshing teeth 57 and 59), meshing portions 61 and 63 of clutch ring 55 and hub member 41, pressing member 69 and opening 67 is supplied to the sliding portion 67, thrust washers 49, 51, etc., and these are lubricated and cooled.

[Operation of front differential 1]
As described above, the meshing clutch 7 of the 2-4 switching mechanism and the front differential 1 is simultaneously connected when switching from the two-wheel drive state to the four-wheel drive state, and is switched from the four-wheel drive state to the two-wheel drive state. At the same time, the disconnection operation is performed.

  In the four-wheel drive state, the driving force of the engine is transmitted from the 2-4 switching mechanism to the differential case 3 via the front wheel side power transmission system, and this rotation is transmitted from the pinion shaft 27 via the pinion gear 29 to the left side gear 31 or The gear member 39, the meshing clutch 7, and the hub member 41 are distributed to the left and right front wheels via the axles. Further, for example, if a difference in driving resistance occurs between the front wheels while traveling on a rough road and either the left or right of the front wheels idles, the driving force of the engine is differentially distributed to the left and right front wheels as each pinion gear 29 rotates.

  In the two-wheel drive state, the gear member 39 and the hub member 41 of the right side gear 33 are disconnected by the meshing clutch 7, and the differential mechanism 5 idles while being differentially driven as the gear member 39 idles. The driving force transmission is cut off and the vehicle is in a two-wheel drive state. Further, since the mesh release force of the meshing clutch 7 is promoted by the cam thrust force generated in the meshing teeth 57 and 59 having the cam angle as described above, the switching from the four-wheel drive state to the two-wheel drive state is quickly performed. Done.

  Further, in the two-wheel drive state, the differential mechanism 5 to both front wheels are in a free rotating state, and the power transmission system from the 2-4 switching mechanism to the differential case 3 is based on both the driving force of the engine and the accompanying rotation by the front wheels. The rotation is cut off and the rotation is stopped. The wear of each part of the front wheel side power transmission system is reduced and the durability is improved. The burden on the engine is reduced by the reduction of the rotation resistance, and the fuel consumption is improved.

[Effect of front differential 1]
Since the front differential 1 is configured as described above, the following effects can be obtained.

  Unlike the conventional example in which the meshing clutch 7 is provided in the axially opposite portion between the gear member 39 of the side gear 33 and the clutch ring 55, the axial direction of the gear member 39 and the clutch ring 55 is different from the conventional example in which the intermittent means is provided on the outer periphery of the split member. It is possible to increase the tooth width of the meshing teeth 57 and 59 by using the wide surface of the facing portion, and to give a sufficient torque capacity (strength).

  Therefore, it is possible to prevent the front differential 1 from being enlarged and the vehicle-mounted performance from being lowered by expanding the tooth width in the axial direction.

  Further, the cam angle is given to the meshing teeth 57 and 59, thereby releasing the engagement of the meshing clutch 7, improving the response for switching from the four-wheel driving state to the two-wheel driving state and operating the meshing clutch 7. Since it is not necessary to increase the size of the gear plate actuator 11 and strengthen the return spring 9, it is possible to avoid an increase in size, weight, in-vehicle performance, cost, etc. of the front differential 1 associated therewith.

  Further, the meshing teeth 59 are integrally formed so as to be located on the back side of the tooth bottom of the gear portion of the gear member 39 of the side gear 33, so that the strength of the gear portion of the gear member is sufficiently ensured and the durability is improved. Is possible.

[Second Embodiment]
The front differential 101 (differential device of the second embodiment) will be described with reference to FIG. Hereinafter, the difference will be described with reference to members having the same functions as those of the front differential 1 with the same reference numerals.

[Features and effects of front differential 101]
The front differential 101 is different from the front differential 1 in that the differential case 3 has a one-piece configuration. An opening 103 is formed in the differential case 3, and each member constituting the meshing clutch 7 with the differential mechanism 5 is assembled from the opening 103 into the differential case 3.

[Effect of front differential 101]
The front differential 101 can obtain the same effect as the front differential 1 of the first embodiment.

  In addition to this, since the inner case is not required due to the effect of intermittent driving force on the side gear (output member), the differential case is used to obtain a large opening (opening of the casing body) for assembling the inner case. There is no need to make the casing body and the cover divided into two parts, and the differential case 3 can be made into a one-piece structure as described above.

  As a result, it is not necessary to set the hole tolerance and hole geometric tolerance of the bolt holes for fastening the ring gear together with the cover 17 and the casing body 15 for single-piece machining, resulting in a significant increase in costs associated with precision machining. In addition to being avoided, set processing performed with the casing main body 15 and the cover 17 assembled is not necessary, and there are steps associated with set processing such as temporary assembly, machining (bolt hole processing), disassembly, cleaning, and reassembly. It is avoided and the cost is greatly reduced.

[Other Embodiments Included within the Scope of the Present Invention]
In the differential device of the present invention, the driving force intermittent means is not limited to the meshing clutch (meshing clutch), and may be, for example, a friction clutch.

  The actuator for operating the intermittent means may be an electromagnetic actuator, a pneumatic actuator, or a hydraulic actuator in addition to the electric actuator as in the embodiment using the electric motor and the cam.

It is sectional drawing which shows 1st Example of the state by which the connection of the interruption means was cancelled | released. It is sectional drawing which shows 1st Example of the state to which the interruption means was connected. It is sectional drawing which shows 2nd Example of the state to which the interruption means was connected. It is sectional drawing of a prior art example.

Explanation of symbols

1 Front differential (differential device)
3 Differential case 5 Bevel gear type differential mechanism 7 Engagement clutch (intermittent means)
9 Return spring 11 Actuator 27 Pinion shaft 29 Pinion gear 31, 33 Side gear (a pair of output members)
39 Gear member of side gear 33 41 Boss member 101 of side gear 33 Front differential (differential device)

Claims (2)

A differential case that rotates in response to the driving force from the prime mover;
A differential mechanism that distributes rotation of the differential case from a pair of output members to each wheel side;
Driving force intermittent means,
One of the output members is composed of two divided members, and the intermittent means is a differential device configured to intermittently connect these divided members,
A differential apparatus, wherein the intermittent means is provided in an axially opposed portion of the dividing member. The invention according to claim 1,
The differential mechanism is a bevel gear type difference composed of a pinion shaft connected to the differential case, a pinion gear supported on the pinion shaft, and a pair of side gears that are the pair of output members respectively engaged with the pinion gear. Dynamic mechanism,
One of the side gears is divided into a gear member meshed with the pinion gear and a boss member connected to the wheel side,
The differential device according to claim 1, wherein the intermittent means is a clutch member connected to the boss member so as to be axially movable, and a meshing clutch provided at an axially opposed portion of the gear member.

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