JP4727956B2 - Differential device casing structure - Google Patents

Description

The present invention relates to a casing structure of a differential device used in, for example, a driving force transmission device that transmits driving force.

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

  The differential device 501 includes a differential case 503, a bevel gear type differential mechanism 505, multi-plate clutches 507 and 507, disc springs 509 and 509, and the like.

  The differential mechanism 505 includes a pinion shaft 511 having both ends connected to the differential case 503, a pinion gear 513 supported on the pinion shaft 511, and output side gears 515 and 517 engaged with these pinion gears 513. The side gears 515 and 517 are connected to the respective wheel sides via axles 519 and 521. The driving force of the engine causes the differential case 503 to rotate from the drive pinion gear 523 via the ring gear 525, and the rotation of the differential case 503 is distributed from the pinion shaft 511 to the side gears 515 and 517 via the pinion gear 513 and transmitted to each wheel side.

The differential case 503 has a two-member configuration of a casing body 527 and a cover 529, and the casing body 527 and the cover 529 are provided with flange portions 531 and 533, respectively. The flange portions 531 and 533 are fixed by bolts 535, and the ring gear 525 is fastened to the flange portions 531 and 533 by bolts 537.
JP-A-9-89086

  The differential case 503 of the differential device 501 is configured so that the diameters of the insertion holes 539 and 541 of the bolts 537 for the ring gear 525 formed in the flange portions 531 and 533 maintain the positional relationship in the circumferential direction between the casing body 527 and the cover 529 normally. That is, the same hole tolerance and the same hole geometric tolerance are set in order to ensure that the positional accuracy of the neck portion 540 and the insertion hole of the bolt 537 is appropriate and the driving force is transmitted.

  The insertion holes 539 and 541 are provided at several locations (for example, four locations) at equal intervals in the circumferential direction, and the corresponding insertion holes 539 and 541 are provided at mutually required locations (the same radial position and circumferential interval). In this case, the hole tolerance and the hole geometric tolerance of the insertion holes 539 and 541 must be set so severely in the casing main body 527 and the cover 529, respectively, and such precision machining greatly increases the cost.

Further, in order to satisfy the hole tolerance and hole geometric tolerance of the insertion holes 539 and 541, set processing performed in a state where the casing main body 527 and the cover 529 are assembled is necessary. This set processing is performed by temporary assembly, machining ( Many processes such as insertion hole processing), disassembly, cleaning, and reassembly are required, which is troublesome and burdens the product cost.

Therefore, the present invention is capable of satisfying the required tolerance even if each member is processed without being set by assembling each member, and the differential device can reduce the cost and reliably transmit the driving force. The purpose is to provide a casing structure.

The invention according to claim 1 is an input member for inputting a driving force from a driving source, a first casing member having an opening in one of the axial directions, a second casing member for closing the opening, and the first The first casing member and the second casing member by passing through bolt insertion holes provided respectively in the casing member and the second casing member and screwing into threaded portions provided in the input member. A casing structure having a bolt to be fastened and an output member driven by the first casing member, wherein the first casing member is disposed on the first casing member and the second casing member. A fitting portion for centering with respect to the second casing member; a flange portion provided on each of the first casing member and the second casing member; A plurality of the bolt insertion holes are respectively formed at equal intervals in the circumferential direction, the bolt includes a neck portion having a diameter substantially equal to any one of the bolt insertion holes, and the bolt includes the first casing member and the bolt Of the second casing member, the first casing member and the second casing member are inserted from the end surface side of one flange portion and screwed into the input member that contacts the end surface side of the other flange portion. and Kyoshime, the output member has two side gears, one of the side gears are supported on said first casing member and the other side gear is supported on the second casing member, the first casing member A diameter of the bolt insertion hole provided in the second casing member is smaller than a diameter of the bolt insertion hole provided in the second casing member.

According to a second aspect of the present invention, there is provided a first rotating member having one or more screwing portions that receives torque from an external member and rotates around an axis, and a second rotating member that rotates together with the first rotating member. A rotating member, wherein the second rotating member includes a first component member having one or more first insertion holes, a second component member having one or more second insertion holes, and the first component member. and one or more bolts for fixing an insertion hole and said second is screwed to the threaded portion is inserted into the insertion hole a second component to the first component, the first An output member driven by the component member, and the first component member and the second component member are fitted to center the first component member with respect to the second component member. A first furan having a first insertion hole. The second component member includes a second flange having the second insertion hole, and the first flange and the second flange include a plurality of the first flanges at equal intervals in the circumferential direction. An insertion hole and the second insertion hole are formed, and the bolt includes a neck portion having substantially the same diameter as any one of the first insertion hole or the second insertion hole, and the bolt includes the first configuration. The first component member and the second configuration screwed into the first rotating member inserted from the end surface side of one flange of the member and the second component member and in contact with the end surface side of the other flange The output member has two side gears, one side gear is supported by the first component member, and the other side gear is supported by the second component member . The first diameter of the insertion hole and the second diameter of the second insertion hole Is different diameter, a casing structure of a differential device for a torque transmission device.

A third aspect of the present invention is the casing structure of the differential device according to the second aspect, wherein the bolt is inserted through the second flange from the first flange side.

The invention of claim 4 is the casing structure of the differential device according to claim 2, wherein the bolt is inserted through the first flange from the second flange side.

In the casing structure of the differential device according to claim 1, the diameter of the bolt insertion hole of the first casing member is made smaller than the diameter of the bolt insertion hole of the second casing member. For example, the second casing member If the bolt insertion hole of the first casing member is made to have an appropriately larger diameter than the bolt insertion hole of the first casing member, the error when these are assembled is absorbed by the large diameter bolt insertion hole of the second casing member, and the first Since the driving force can be transmitted on the casing member side, it is not necessary to strictly set the hole tolerance and geometric tolerance of both bolt insertion holes, and a significant increase in cost associated with precision machining can be avoided. Further, the bolt insertion hole of the first casing member has a small diameter and can contact the bolt with a tight gap so that the driving force can be reliably transmitted from the screwed portion of the input member to the first casing member via the bolt. .

  In addition, since the set processing performed in the state where the first and second casing members are assembled is unnecessary, the process and cost associated with the set processing such as temporary assembly, machining (bolt hole processing), disassembly, cleaning, reassembly, etc. The rise of is greatly avoided.

Moreover, the 1st and 2nd casing member is fastened together between the volt | bolt and the input member by the flange part provided in each. Therefore, for example, as in a differential device, by increasing the rotation radius (radius from the rotation axis of the casing to the bolt position) to which torque is input, a large burden is not applied to the bolt (in the case of a plurality of bolts). The driving force can be transmitted on the first casing member side, and the bolt tightening torque is maintained even when the input torque fluctuates, and the frictional force acting on the end face of the flange is properly maintained over a long period of time. Drive force can be transmitted.

  In addition, the support of the output member can be distributed to the first and second casing members, and the degree of freedom in design when a plurality of torque transmission members are arranged inside the casing is improved.

In the casing structure of the differential apparatus of Claim 2 thru | or 4 , by making the 1st diameter and the 2nd diameter into different diameters, a 1st rotation member, a 1st structural member, a 2nd structural member since error when assembled is absorbed by the bolt insertion hole of the large diameter side, it is not necessary to strictly set the hole tolerances and geometric tolerances of both the bolt insertion holes, avoiding a significant increase in cost associated with precision machining It is done.

The differential case 1 ( the casing structure of the differential device of the present invention, the second rotating member in claim 2 ) and the front differential 3 will be described with reference to FIGS. The front differential 3 is configured using a differential case 1. The left and right directions are the vehicle using the front differential 3 and the left and right directions in FIGS. 1 and 2.

The differential case 1, (first casing member definitive to claim 1, the first component in claim 2) casing body having an opening 31 in one axial direction and 15, the cover (claim 1 for closing the opening 31 definitive second casing member, the second component) 17 in claim 2, inserted through the casing body 15 and respectively provided with bolt holes in the cover 17 (bolt insertion holes) 35 and 37 on the bolt 21 secured to each other As a result, the diameter of the bolt hole 35 provided in the casing body 15 and the diameter of the bolt hole 37 provided in the cover 17 are different from each other by rotating under the driving force from the prime mover. The hole tolerance and the hole geometric tolerance of the bolt hole 37 are moderated to avoid an increase in cost due to precision machining, and the casing body 15 and the cover 17 are assembled. It eliminates the need for preparative work, temporary assembly, (machining bolt holes) machining, disassembly, cleaning, reassembly, etc., avoiding an increase in steps and costs associated with the set processing.

  The front differential 3 (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, and cuts the driving force toward the front wheels when driving two wheels. It is configured as follows.

  The power transmission system of this four-wheel drive vehicle includes an engine (motor), transmission, transfer, 2-4 switching mechanism, front wheel propeller shaft, front differential 3, front axle, left and right front wheels, rear wheel 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. While the 2-4 switching mechanism and the front differential 3 are connected to each other, 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 3 to the left and right front wheels via the front axle. The vehicle is in a four-wheel drive state. Further, when the connection between the 2-4 switching mechanism and the front differential 3 is released, the front wheel side is disconnected from the engine, and the vehicle enters a two-wheel drive state. 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 3, and the driving force to the front wheel side is interrupted.

  The front differential 3 includes a differential case 1, an inner case 5, a bevel gear type differential mechanism 7, a dog clutch 9, a ring-shaped pneumatic actuator 11, a return spring 13, and the like. The front differential 3 is disposed inside the transfer case, and an oil sump is formed in the transfer case.

  The differential case 1 is composed of a casing body 15 and a cover 17 and bolts 19 and 21 for fixing them together. Boss portions 23 and 25 formed respectively on the casing body 15 and the cover 17 are attached to a transfer case via bearings. It is supported. The casing body 15 and the cover 17 are respectively formed with flange portions 27 and 29, and the casing body 15 is provided with an opening 31 facing leftward. The casing body 15 and the cover 17 are assembled with each other by fixing flange portions 27 and 29 with bolts 19 at a plurality of locations in the circumferential direction. Reference numeral 28 denotes a neck provided on the bolt 21, which faces the bolt holes 35 and 37. At this time, the casing body 15 and the cover 17 are centered with each other by an inlay portion 33 formed between the opening 31 and the cover 17, and the cover 17 closes the opening 31.

Further, the flange portion 27, 29 and 10 of the bolt holes 35, 37 respectively are formed in the circumferential direction at equal intervals, the bolt 21 is definitive through bolt holes 35, 37 in the ring gear (claim 1 input member, wherein The first rotating member 39 in item 2 is screwed to the flange portions 27 and 29 together. The ring gear 39 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 1 is rotated.

  In the differential case 1 of the present invention, the diameter b of the cover 17 side bolt hole 37 is larger than the diameter a of the casing body 15 side bolt 35 as shown in FIG. As shown in FIG. 2B, the diameter b of the cover 17 side bolt hole 37 may be smaller than the diameter a of the casing body 15 side bolt hole 35. That is, the diameter b of the cover 17 side bolt hole 37 and the diameter a of the casing body 15 side bolt hole 35 are different from each other.

  The inner case 5 is supported on the inner periphery of the differential case 1 (casing body 15) so as to be slidable and rotatable.

  The differential mechanism 7 includes a plurality of pinion shafts 41, a pinion gear 43 that is rotatably supported on each pinion shaft 41, and left and right output side gears 45 and 47. Each pinion shaft 41 is engaged with a through hole 49 of the inner case 5 at its tip and is prevented from being detached by a spring pin 51. The side gears 45 and 47 mesh with the pinion gear 43 from the left and right.

  Boss portions 53, 55 of the side gears 45, 47 are supported by support portions 57, 59 formed on the cover 17 and the casing body 15, respectively, and left and right front axles are splined to the boss portions 53, 55, respectively. Has been. A thrust washer 61 is disposed between each side gear 45, 47 and the differential case 1, and receives the meshing thrust force of the side gears 45, 47. A spherical washer portion 63 is formed on the inner periphery of the inner case 5 so as to face each pinion gear 43, and the engagement received by the pinion gear 43 due to the centrifugal force of the pinion gear 43 and the engagement with the side gears 45 and 47. It bears the reaction force.

  The dog clutch 9 includes a meshing tooth 67 formed on the clutch ring 65 and a meshing tooth 69 formed on the inner case 5. The clutch ring 65 is supported on the inner periphery of the casing body 15 so as to be movable in the axial direction. The casing body 15 has openings 71 through which oil flows in and out at equal intervals in the circumferential direction. The clutch ring 65 has four leg portions 73 provided at equal intervals in the circumferential direction at the right end. Engage and protrude outward.

  When the clutch ring 65 is moved to the left and right and moved to the left, the dog clutch 9 is engaged and the differential case 1 and the inner case 5 are connected. When the clutch ring 65 returns to the right, the engagement of the dog clutch 9 is released and the differential case is released. 1 and the inner case 5 are separated.

  In addition, the code | symbol 41, 43, 45, 47, 55, 73 etc. which are arrange | positioned in the differential case 1 correspond to the output member of this invention.

  The ring-shaped pneumatic actuator 11 is disposed around the boss portion 23 of the differential case 1 (casing body 15), and is supported by the transfer case via the support member 75 and is prevented from rotating. The pressure chamber 77 of the actuator 11 is formed by airtightly fixing a diaphragm 81 to a base member 79, and a pressing member 83 is fixed to the diaphragm 81.

A retainer 85 is disposed between the actuator 11 (pressing member 83) and the clutch ring 65.

  The retainer 85 is provided with a radial locking arm 87 at a position corresponding to the four legs 73 of the clutch ring 65, and an axial locking arm 89 is formed on each locking arm 87. ing. The retainer 85 is connected to the clutch ring 65 so as to be movable together by sandwiching the leg portion 73 between the locking arm 87 and the locking arm 89.

  Four return springs 13 are formed at equal intervals in the circumferential direction of the retainer 85, come into contact with the right end surface of the casing body 15, and urge the clutch ring 65 in the meshing release direction (rightward) of the dog clutch 9. Yes.

  The pressure chamber 77 of the actuator 11 is connected to a vehicle-mounted compressor via an air pipe 91, and when air pressure is sent to the pressure chamber 77, the diaphragm 81 is displaced to the left, and each return spring 13 of the retainer 85 is bent. However, the clutch ring 65 is moved to the left via the pressing member 83 and the retainer 85 to engage the dog clutch 9. When the supply of air pressure to the pressure chamber 77 is stopped, the clutch ring 65 returns to the right by the urging force of each return spring 13 and the engagement of the dog clutch 9 is released.

  As described above, the 2-4 switching mechanism and the dog clutch 9 of the front differential 3 are simultaneously connected when switching from the two-wheel drive state to the four-wheel drive state and 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 1 via the front wheel side power transmission system, and the inner case 5 is rotationally driven via the dog clutch 9. This rotation is distributed from the pinion shaft 41 to the side gears 45 and 47 through the pinion gear 43 and transmitted to the left and right front wheels through 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 the pinion gears 43 rotate. .

  In the two-wheel drive state, the dog clutch 9 causes the inner case 5 to the front wheel to rotate freely, and the power transmission system from the 2-4 switching mechanism to the differential case 1 is both the driving force of the engine and the accompanying rotation by the front wheel. Rotation stops after being disconnected from. In the two-wheel drive state, rotation of the front wheel side power transmission system stops in this way, vibration is reduced and riding comfort is improved, and wear is reduced at each part of the front wheel side power transmission system, and durability is improved. In addition, the burden on the engine is reduced by the reduction in rotational resistance, and fuel efficiency is improved.

  In addition to the opening 71, spiral oil grooves are formed in the inner periphery of the boss portions 23 and 25 in the differential case 1, and the oil in the oil reservoir formed in the transfer case is accompanied by the rotation of the differential case 1. The sliding portion between the casing body 15 and the inner case 5, the meshing portion of the gears 43, 45, 47, the sliding portion of the pinion shaft 41 and the pinion gear 43, and the sliding portion of the casing body 15 and the clutch ring 65 , And supplied to the dog clutch 9 (meshing teeth 67, 69) to lubricate and cool them.

  The differential case 1 is configured as described above, and the following effects are obtained.

  Since the diameter b of the cover 17 side bolt hole 37 and the diameter a of the casing main body 15 side bolt hole 35 are different, errors when assembled are absorbed by the difference between the diameter a and the diameter b. Therefore, it is not necessary to strictly set the hole tolerance and the hole geometric tolerance of both the bolt holes 35 and 37 for single-piece machining, and therefore, a significant cost increase associated with precision machining can be avoided.

  In addition, since any one of the bolt holes 35 and 37 is in contact with the bolt 21 with a tight gap, the driving force can be reliably transmitted to the casing body 15 from the screwed portion of the input member via the bolt 21.

  Moreover, since the set processing performed in the state where the casing body 15 and the cover 17 are assembled is not necessary, steps associated with the set processing such as temporary assembly, machining (bolt hole processing), disassembly, cleaning, and reassembly are avoided. Cost is reduced accordingly.

  In the example of FIG. 2A in which the bolt hole 37 of the cover 17 has a larger diameter than the bolt hole 35 of the casing body 15 that bears most of the input torque from the ring gear 39, the torque is transmitted from the ring gear 39 to the casing. It is transmitted to the main body 15. In the example of FIG. 2B, torque is transmitted from the ring gear 39 to the cover 17, and is transmitted to the casing body 15 through a wide crimping surface by the flanges 27 and 29. Both the bolt holes 35 and 37 have a gap with respect to the bolt 21, and the cover 17, the bolt 21, and the ring gear are compared with the case where torque is transmitted exclusively by the crimping surface between the ring gear 39 and the casing body 15. 39 is not burdened.

  In addition, since the difference between the diameter b of the cover 17 side bolt hole 37 and the diameter a of the casing body 15 side bolt hole 35 is set to a small range of 0.1 to 0.3 mm, the left side gear by the cover 17 (support portion 57). 45 and the support of the right side gear 47 by the casing body 15 (supporting portion 59) are normally performed.

  Further, since the casing body 15 and the cover 17 are fastened together by the bolts 21 and the ring gear 39 by the flange portions 27 and 29 provided respectively, the rotation radius (the bolt position from the rotation axis of the casing body 15) is inputted. By increasing the radius), the bolts 21 are not subjected to a large burden, the driving force can be transmitted on the casing body 15 side, and the bolt tightening torque is maintained even when the torque varies, and the flange portion 27 The frictional force acting on the end face 29 is also properly maintained over a long period of time, so that a reliable driving force can be transmitted.

  Further, the support of the output member (for example, the side gear) can be distributed to the casing body 15 and the cover 17, and the degree of design freedom when a plurality of torque transmitting members are arranged inside the differential case is improved.

[Other Embodiments Included within the Scope of the Present Invention]
Note that the casing structure of the present invention is not limited to the differential case, unlike the above-described embodiments, and may be used, for example, for a coupling that interrupts power.

  Moreover, in the said Example, although the difference of the diameter b of the cover side bolt hole and the diameter a of the casing main body side bolt hole is set in the range of 0.1-0.3 mm, the cover of the large diameter bolt hole side is set. In this case, the difference between the diameter b and the diameter a may be set to be a little larger, such as several mm, within a range in which a sufficient area can be obtained on the seat surface 93 of the bolt.

  Further, the arrangement of the flanges 27 and 29, the input member 39 and the bolt 21 in the axial direction will be described in accordance with the paper surface of FIG. 1 as another aspect. The input member 39 is arranged on the leftmost side and is arranged on the right side. 2, a flange 29 as a casing member, a flange 27 as a first casing member, and a bolt 21. The bolt 21 penetrates the flanges 27 and 29 from the right end surface side of the flange 27 toward the left in the axial direction. Alternatively, the screw member may be screwed into the screw portion provided on the input member arranged on the leftmost side and fastened together.

  Further, the differential device using the casing structure of the present invention is not limited to the one using the intermittent function as in the above-described embodiment, and even a differential device having a differential limiting function does not have a differential limiting function. But you can. Further, when the intermittent function or the differential limiting function is operated by an actuator, the actuator may be pneumatic, hydraulic, or electric.

  Furthermore, the casing structure of the present invention can be applied not only to a differential device but also to a casing structure in another driving force transmission device such as a transfer.

It is sectional drawing which shows one Example of this invention. It is an enlarged view which shows the principal part of FIG. It is sectional drawing of a prior art example.

Explanation of symbols

1 Differential case (second rotating member)
3 Front differential (differential device)
7 Differential mechanism (third rotating member)
15 casing body (first casing member, first component)
17 Cover (second casing member, second component member)
21 Bolt 27 Flange portion 29 of casing body Flange portion 31 of cover 31 Opening of casing body 35 Bolt hole of casing body (bolt insertion hole)
37 Bolt hole 39 of cover 39 Ring gear (input member, first rotating member)
45, 47 Output side gear

Claims (4)

An input member for inputting a driving force from a driving source, a first casing member having an opening in one axial direction, a second casing member for closing the opening, the first casing member, and the second casing A bolt that penetrates a bolt insertion hole provided in each of the casing members and is screwed into a threaded portion provided in the input member to jointly fasten the first casing member and the second casing member, A differential structure casing having an output member driven by a first casing member,
The first casing member and the second casing member include a fitting portion that centers the first casing member with respect to the second casing member,
The first casing member and the second casing member are respectively provided with flange portions, and a plurality of the bolt insertion holes are formed in each flange portion at equal intervals in the circumferential direction. A neck portion having a diameter substantially the same as that of the first casing member and the second casing member, and the bolt is inserted from an end surface side of one flange portion of the first casing member and the second casing member. Threadedly engaged with the input member abutting and fastening the first casing member and the second casing member together;
The output member has two side gears , one side gear is supported by the first casing member, and the other side gear is supported by the second casing member.
A casing structure characterized in that a diameter of the bolt insertion hole provided in the first casing member is smaller than a diameter of the bolt insertion hole provided in the second casing member. A first rotating member having one or more screwing portions that transmit and receive torque with an external member and rotate around an axis;
A second rotating member that rotates together with the first rotating member,
The second rotating member includes a first component member having one or more first insertion holes, a second component member having one or more second insertion holes, the first insertion hole, and the first rotation member , respectively. One or more bolts inserted into the second insertion hole and screwed into the threaded portion to fix the second component member to the first component member, and driven by the first component member An output member ,
The first component member and the second component member include a fitting portion that centers the first component member with respect to the second component member,
The first component member includes a first flange having the first insertion hole,
The second component member includes a second flange having the second insertion hole,
A plurality of the first insertion holes and the second insertion holes are formed at equal intervals in the circumferential direction on the first flange and the second flange,
The bolt includes a neck portion having substantially the same diameter as any one of the first insertion hole or the second insertion hole,
The bolt is inserted from the end face side of one flange of the first constituent member and the second constituent member, and is screwed into the first rotating member that contacts the end face side of the other flange. The component member and the second component member are fastened together,
The output member has two side gears, one side gear is supported by the first component, and the other side gear is supported by the second component.
A casing structure of a differential device for a torque transmission device, wherein a first diameter of the first insertion hole is different from a second diameter of the second insertion hole. The casing structure of the differential device according to claim 2, wherein the bolt is inserted through the second flange from the first flange side. The casing structure of the differential device according to claim 2, wherein the bolt is inserted from the second flange side through the first flange.

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