JP4151887B2 - Clutch device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clutch device, and more particularly to a lubrication structure for a multi-plate clutch.
[0002]
[Prior art]
For example, a transfer clutch built in an automatic transmission (AT) for a four-wheel drive vehicle (4WD) includes a clutch drum, a clutch hub, and a plate group (drive plate and driven) arranged alternately between them. Plate). Since the facing surface of the plate and the part where the spline is fitted correspond to heat generation, wear, and the like, it is necessary to supply oil to these and lubricate them.
[0003]
FIG. 9 is a cross-sectional view of a conventional clutch hub, and shows a cross-sectional shape of the upper half with respect to an axis indicated by a one-dot chain line. The clutch hub 50 has a spline portion 50a in which a spline extending in the axial direction is formed on the outer peripheral surface. Further, at both ends of the spline portion 50a, ribs 51 projecting toward the inner peripheral surface side (downward in the figure) are integrally formed in an annular shape. The rib 51 functions as a damming portion that restricts the oil in the oil reservoir 52 from flowing out from the end portion. When the clutch hub 50 rotates, the oil supplied from the rotating shaft of the clutch hub 50 is accumulated in the oil reservoir 52 by centrifugal force. The accumulated oil is discharged from an oil discharge hole 53 penetrating the radial direction of the spline portion 50a, whereby the members arranged on the outer peripheral surface side of the spline portion 50a, that is, the drive plate and the driven plate are lubricated. Is done.
[0004]
[Problems to be solved by the invention]
However, the clutch hub 50 having the structure described above has a limit in reducing the manufacturing cost because the manufacturing process becomes complicated. For example, when the clutch hub 50 is sintered and molded, it is necessary to remove the frame of the clutch hub 50. In the sintering process, the rib 51 cannot be formed, and in order to allow the frame to be removed, a draft is formed in a portion corresponding to the oil sump 52 (tapered shape that expands toward the end). It is necessary to provide. And after taking out the clutch hub 50, the rib 51 and the oil sump 52 are formed by the cutting process by a lathe, and the oil discharge hole 53 is formed by the drilling process by a drill. As described above, the conventional clutch hub 50 has a disadvantage in that the manufacturing cost is increased because it is necessary to perform machining after sintering.
[0005]
The present invention has been made in view of such circumstances, and an object thereof is to reduce the manufacturing cost of the clutch hub.
[0006]
[Means for Solving the Problems]
In order to solve such a problem, a clutch device according to the present invention includes a clutch drum having a spline formed on an inner peripheral surface, and a clutch hub that is disposed in the clutch drum and has a spline portion formed on the outer peripheral surface. And a plurality of hub side plates that are spline-fitted with the clutch hub, an inner peripheral surface of the clutch drum, and an outer peripheral surface of the clutch hub. is arranged between the, together they are arranged alternately with the hub-side plate, and a plurality of drum-side plate fitted clutch drum and spline. The end portion of the spline portion has at least one first end surface having an arc shape extending in the circumferential direction of the clutch hub, and at least one second end surface. The second end surface protrudes more in the axial direction than the first end surface. In addition, the hub side plate located between the first end surface and the second end surface in the axial direction has an inner diameter smaller than the inner diameter of the spline portion of the clutch hub, and a protruding portion including the second end surface An opening for insertion engagement is provided.
[0007]
Here, in the present invention, it is preferable to provide an oil groove that communicates between the radially inner side and the outer side of the clutch hub on the first end surface.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view of an automatic transmission (AT) for a four-wheel drive vehicle (4WD) to which a clutch device according to this embodiment is applied. Power from an engine (not shown) is transmitted to the input shaft 3 of the automatic transmission 1 via the torque converter 2. The power transmitted to the input shaft 3 is output after being shifted by a speed change mechanism including two planetary gears A and B, a high clutch 6, a reverse clutch 7, a 2 & 4 brake 8, a low clutch 9, a low & reverse brake 10, and the like. It is transmitted to the shaft 4. These clutches / brakes 6 to 10 are engaged / released by hydraulic control by the control valve 11, and the gear position is set accordingly. Then, the shifted power transmitted to the output shaft 4 is input to the center differential and distributed, and one power is transmitted to the drive pinion shaft 5 via the carrier 16, the reduction drive gear 12 and the reduction driven gear 13. Then, it is transmitted to the front wheels via the differential device 14. The other power is transmitted to the rear drive shaft 15 that drives the rear wheels via the second sun gear 20. An operation limiting clutch 30 is provided between the carrier 16 which is a member for transmitting the distributed power and the rear drive shaft 15.
[0010]
FIG. 2 is a cross-sectional view of the clutch device according to the present embodiment, showing a 4WD center differential 60 and a differential limiting clutch 30 (hereinafter referred to as a transfer clutch 30) provided thereon. The center differential 60 includes a first sun gear 17 formed on the output shaft 4 of the transmission 1, a second sun gear 20 formed on the rear drive shaft 15, and an integrally formed first gear that meshes with the sun gears 17 and 20. The pinion 18, the second pinion 19, and the carrier 16 that pivotally supports these pinions 18, 19 are configured in a composite planetary gear type. A transfer clutch 30 is provided between the carrier 16 as the output member on the front wheel side and the rear drive shaft 15 as the output member on the rear wheel side. The center differential 60 configured as described above distributes power at a basic distribution ratio to the front wheel side and the rear wheel side by setting the gear specifications of the planetary gear. Then, according to the traveling state and the road surface state, for example, when the rear wheel side slips, the transfer clutch 30 is engaged and the differential rotation of the center differential 60 is controlled. The power transmitted to the rear wheel side is caused to flow to the front wheel side by the transfer clutch 30, so that driving force is secured as a 4WD vehicle, and traveling performance can be improved.
[0011]
The automatic transmission 1 is provided with a lubricating oil passage 22 that communicates between the output shaft 4 and the rear drive shaft 15 that are arranged coaxially with the input shaft 3. Oil discharged from the oil pump 21 is supplied. The shafts 3, 4 and 15 are provided with a plurality of oil holes 24 to 29 which communicate with the lubricating oil passage 22 and extend in the radial direction. The oil discharged from these oil holes 24 to 29 lubricates the above-described speed change mechanism, transfer clutch 30 and the like.
[0012]
The transfer clutch 30 is mainly composed of a clutch drum 31, a clutch hub 33, a plurality of drive plates 40 and 42, and a plurality of driven plates 45. The clutch drum 31 has a spline portion 32 having a spline formed on the inner peripheral surface thereof. A clutch hub 33 that is spline-fitted to the rear drive shaft 15 is disposed inside the clutch drum 31.
[0013]
3 is a front view of the clutch hub 33, FIG. 4 is a plan view, and FIG. 5 is a cross-sectional view taken along line AA in FIG. The clutch hub 33 can be formed only by sintering without performing machining such as cutting or drilling. As shown in FIG. 5, the clutch hub 33 has a substantially E-shaped cross section, an inner peripheral portion 33a having an inner spline on the inner periphery, a spline portion 35, and a flange connecting these portions 33a, 35. It has a portion 33c. The inner peripheral portion 33a is spline-fitted with the rear drive shaft 15, and a plurality of first oil grooves 34 are provided on the end surface thereof in the radial direction.
[0014]
The spline portion 35 corresponds to the outer peripheral portion of the clutch hub 33, and a spline is provided on the outer peripheral surface thereof. Further, as shown in FIG. 3, the end portions (both ends in the present embodiment) of the spline portion 35 have four first end surfaces 36 and four second end surfaces 37 alternately along the circumferential direction. Is provided. The second end surface 37 protrudes in the axial direction from the first end surface 36. In other words, the end portion of the spline portion 35 has a notch portion (concave portion) corresponding to the first end surface 36 and a protruding portion (convex portion) corresponding to the second end surface 37 in the circumferential direction. Are alternately adjacent to each other. A second oil groove 39 is provided in each of the recessed first end surfaces 36, and the second oil groove 39 communicates between the radially inner side and the outer side of the clutch hub 33. To do. Note that the number of the first and second end surfaces 36 and 37 is sufficient if at least one of each is present, but a plurality of the first and second end surfaces 36 and 37 are preferably provided.
[0015]
FIG. 6 is an enlarged cross-sectional view showing a main part of the transfer clutch 30. FIG. 7 is an exploded view of the drive plates 40 and 42 and the driven plate 45. FIG. 8 is a diagram showing an engaged state between the clutch hub 33 and the drive plate 42. As shown in FIGS. 6 and 7, a plurality of drive plates 40 and 42 and a plurality of driven plates 45 alternate in the axial direction between the inner peripheral surface of the clutch drum 31 and the outer peripheral surface of the clutch hub 33. Is arranged. Of these, a facing material is bonded to the side surfaces of the drive plates 40 and 42 in order to ensure a frictional force during fastening.
[0016]
Here, each of the first drive plates 40 disposed in the middle is disposed between a pair of adjacent driven plates 45. Inner splines that are splined with the spline portions 35 of the clutch hub 33 are formed on the inner peripheral portions of the first drive plates 40.
[0017]
On the other hand, the second drive plate 42 located on the end side, that is, between the first end surface 36 and the second end surface 37 is also disposed between the pair of adjacent driven plates 45. The second drive plate 42 has an inner diameter that is smaller than the inner diameter of the spline portion 35 of the clutch hub 33, and a plurality of openings 43 are provided in the circumferential direction. In these openings 43, splines that can be fitted with the spline portions 35 of the clutch hub 33 are formed. The opening 43 is provided in a position corresponding to the second end surface 37 of the spline portion 35 of the clutch hub 33, and is engaged with a projecting portion (convex portion) including the second end surface 37 of the clutch hub 33. Match.
[0018]
An outer spline is formed on the outer peripheral portion of each driven plate 45, and this outer spline is spline-fitted with the spline portion 32 of the clutch drum 31.
[0019]
The reason why the inner diameter of the second drive plate 42 positioned at both ends is made smaller than the inner diameter of the spline portion 35 is to provide the plate 42 with an oil damming function. As shown in the assembled state of FIG. 6, the second drive plate 42 protrudes in a rib shape on the inner peripheral surface side of the spline portion 35. As a result, an oil sump 47 is formed on the inner peripheral surface of the spline portion 35 by the protruding portion of the second drive plate 42 and the flange portion 33c. When the rear drive shaft 15 rotates, the oil discharged from the oil hole 29 is stored in the oil reservoir 47. That is, most of the oil discharged from the oil hole 29 of the rear drive shaft 15 flows along the flange portion 33 c of the clutch hub 33 by the centrifugal force accompanying the rotation of the clutch hub 33, and accumulates in the oil reservoir 47.
[0020]
As described above, the second end surface 37 protrudes more in the axial direction than the first end surface 36. For this reason, when the second drive plate 42 is spline-fitted to the spline portion 35 of the clutch hub 33, the protruding portion including the second end surface 37 engages with the opening 43 of the second drive plate 42. The first end surface 36 corresponding to the notch portion and the side surface of the second drive plate 42 are set so that a slight gap is generated in the clutch engaged state. Therefore, an oil discharge port that communicates between the inside and the outside of the spline portion 35 is formed by the gap between the first end face 36 and the second drive plate 42 and the second oil groove 39. As a result, the oil accumulated in the oil reservoir 47 flows through the oil discharge port and is discharged toward the outer peripheral surface side of the clutch hub 33.
[0021]
Thus, in the present embodiment, the oil sump 47 can be formed simply by spline fitting the drive plates 40 and 42 and the driven plate 45 between the clutch drum 31 and the clutch hub 33. Become. For this reason, it is not necessary to perform machining such as cutting and drilling on the clutch hub 33. As a result, the manufacturing cost of the clutch hub 33 can be reduced, and the oil reservoir 47 can be easily formed.
[0022]
In the above-described embodiment, the clutch hub 33 having a substantially E-shaped cross section has been described as an example. However, the present invention is not limited to this, and may be, for example, a drum shape. . In the present embodiment, the transfer clutch 30 has been described as an example of the clutch device, but the present invention can also be applied to other multi-plate clutches.
[0023]
In the above-described embodiment, the second drive plate 42 having a shape different from that of the first drive plate 40 is used as the drive plate positioned between the first end surface 36 and the second end surface 37 in the axial direction. Used. However, a plate having the same shape as that of the first drive plate 40 may be used as the end plate. In this case, the end drive plate does not have a blocking function. However, since the oil that has flowed into the oil reservoir 47 is supplied to the outer peripheral surface side of the spline portion 35 via the first end face 36 that communicates radially inside and outside, the plates can be lubricated. In this case, since the entire first end face 36 functions as an oil passage, it is not always necessary to form the above-described second oil groove 39 in the first end face 36.
[0024]
【The invention's effect】
Thus, according to the present invention, a lubrication structure for a multi-plate clutch can be realized simply by spline-fitting and assembling the drive plate and the driven plate between the clutch drum and the clutch hub. Further, the clutch hub does not necessarily need to be machined such as cutting with a lathe or drilling with a drill. As a result, the manufacturing cost of the clutch hub can be reduced.
[Brief description of the drawings]
1 is a cross-sectional view of an automatic transmission to which a clutch device according to the present embodiment is applied. FIG. 2 is a cross-sectional view of a transfer clutch. FIG. 3 is a front view of a clutch hub. 3 is a cross-sectional view taken along the line AA in FIG. 3. FIG. 6 is an enlarged cross-sectional view showing the main part of the transfer clutch. FIG. 7 is an exploded view of the drive plate and the driven plate. Fig. 9 is a sectional view of a conventional clutch hub.
30 Differential limiting clutch (transfer clutch)
31 Clutch drum 32 Spline portion 33 Clutch hub 33a Inner peripheral portion 33c Flange portion 34 First oil groove 35 Spline portion 36 First end surface 37 Second end surface 39 Second oil groove 40 First drive plate 42 Second Drive plate 43 Opening 45 Driven plate 47 Oil reservoir

Claims (2)

In the clutch device,
A clutch drum having splines formed on the inner peripheral surface;
A clutch hub disposed in the clutch drum and having a spline part formed with a spline on the outer peripheral surface;
A plurality of hub-side plates that are disposed between the inner peripheral surface of the clutch drum and the outer peripheral surface of the clutch hub, and are spline-fitted with the clutch hub;
Wherein is disposed between the inner peripheral surface of the clutch drum and the outer peripheral surface of the clutch hub, with are arranged alternately with the hub-side plate, a plurality of drum-side plate fitted said clutch drum and spline Have
The end of the spline part is
At least one first end surface having an arc shape extending in a circumferential direction of the clutch hub;
Having a circular arc shape extending in a circumferential direction of the clutch hub, and having at least one second end surface protruding in an axial direction from the first end surface ;
In the axial direction, the hub side plate positioned between the first end surface and the second end surface has an inner diameter smaller than the inner diameter of the spline portion, and is inserted through the protruding portion including the second end surface. A clutch device having an opening to be engaged. 2. The clutch device according to claim 1, wherein an oil groove is provided on the first end face to communicate between the radially inner side and the outer side of the clutch hub.
Place.

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