JP4721567B2 - Wet friction clutch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a wet friction clutch used in a vehicle coupling or a differential device.ToRelated.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 10-329562 describes a driving force transmission device 301 as shown in FIG.
[0003]
The driving force transmission device 301 includes a rotation case 303, an inner shaft 305, a main clutch 307, a ball cam 309, a pressure plate 311, a cam ring 313, a pilot clutch 315, an armature 317, an electromagnet 319, and the like.
[0004]
The driving force transmission device 301 is arranged by dividing a propeller shaft on the rear wheel side that is separated when the two-wheel drive vehicle is driven in a four-wheel drive vehicle, the rotating case 303 is connected to the front propeller shaft, and the inner shaft 305 is arranged on the rear side. It is connected to the side propeller shaft.
[0005]
The rotating case 303 includes a cylindrical member 321 to which a main clutch 307 is connected, and a rotor 323. The rotor 323 constitutes a part of the magnetic path of the electromagnet 319, and the cylindrical member 321 is a magnetic flux from the magnetic path. Made of stainless steel to prevent leakage.
[0006]
The main clutch 307 is a multi-plate clutch disposed between the cylindrical member 321 and the inner shaft 305, and the ball cam 309 is provided between a pressure plate 311 and a cam ring 313 movably connected to the inner shaft 305. It has been.
[0007]
The pilot clutch 315 is a multi-plate clutch and is sandwiched between the armature 317 and the rotor 323.
[0008]
In this driving force transmission device 301, the magnetic path of the electromagnet 319 is formed like a magnetic line of force 325 by the rotor 323, the pilot clutch 315, the armature 317, etc. When the electromagnet 319 is excited, the armature 317 is attracted by the magnetic line of force 325. Therefore, the pilot clutch 315 is pressed and fastened.
[0009]
When the pilot clutch 315 is engaged, a pilot torque is generated and the driving force of the engine is applied to the ball cam 309. The main clutch 307 is pressed by the generated cam thrust force, and the driving force transmission device 301 is connected to drive to the rear wheel side. The force is transmitted and the vehicle is in a four-wheel drive state.
[0010]
When the excitation of the electromagnet 319 is stopped, the pilot clutch 315 is released, the cam thrust force of the ball cam 309 disappears, the main clutch 307 is released, the connection of the driving force transmission device 301 is released, and the rear wheel side is disconnected. The vehicle is in a two-wheel drive state.
[0011]
The pilot clutch 315 composed of a multi-plate clutch is configured by alternately laminating a plurality of outer plates and inner plates. Further, the outer plate is engaged with the cylindrical member 321, and engagement protrusions for the outer plate are formed at regular intervals on the outer peripheral side. The inner plate engages with the cam ring 313, and engaging protrusions for the inner plate are formed at regular intervals on the inner peripheral side.
[0012]
In the pilot clutch 315, the armature 317 is attracted by the magnetic lines of force 325 of the electromagnet 319, whereby the laminated outer plate and inner plate are brought into close contact with each other to generate a frictional force and fasten. On the other hand, when the pilot clutch 315 is not engaged, the outer plate and the inner plate slide relative to each other, so it is necessary to lubricate with oil, and the rotating case 303 is filled with oil.
[0013]
[Problems to be solved by the invention]
In the pilot clutch 315, since the outer plate and the inner plate slide in a laminated state even when the two-wheel drive without energizing the electromagnet 319, the drag torque between the adjacent clutch plates due to the viscosity of the oil at a low temperature or the like. May occur. When the drag torque exceeds a certain level, the state is the same as when the outer plate and the inner plate are fastened, pilot torque is generated in the pilot clutch 315, and a pressing force acts on the main clutch 307 via the ball cam 309, so that the rear wheel The driving force may be transmitted to the side.
[0014]
If the driving force is transmitted to the rear wheel when it is not necessary in this way, a driving loss occurs, which affects the running performance and fuel consumption of the vehicle.
[0015]
  Therefore, the present invention can suppress the drag torque between the clutch plates, and the clutch plates are not fastened when not needed. When applied to a vehicle power transmission mechanism (coupling) or the like, Wet friction clutch that has no effect and can improve fuel efficiencyHThe purpose is to provide.
[0016]
[Means for Solving the Problems]
  The wet friction clutch of the invention of claim 1 is disposed between the torque transmission members on one side and the other side.Fastened by electromagnet excitationA wet friction clutch, wherein the wet friction clutches are overlapped to slide relative to each other.In addition to having a sliding portion in which a magnetic path is formed by excitation of the electromagnet, and having arc-shaped gap portions formed at regular intervals in the circumferential direction to prevent short-circuiting of the magnetic path, the axial direction is alternated Arranged on the outer side and the inner side that are connected to the torque transmission members on the one side and the other side via the respective engaging projections.Consists of clutch plates and adjacentOutside and insideAt least one of the clutch platesOn the sliding surfaceAn oil introduction path for guiding the oil is provided, and the oil introduction pathIs provided in communication with the arc-shaped gap portion and having a non-opening tip portion in the radial direction on the engagement projection side.It is characterized by communicating with the oil chamber.
[0017]
In this invention, since the oil introduction path provided in one of the adjacent clutch plates communicates with the oil chamber, when the clutch plate rotates, oil is supplied to the oil introduction path by the Weisenberg effect, and the clutch plate slides. Since the oil is guided to the moving part, the adjacent clutch plate is smoothly separated by the introduced oil. For this reason, the drag torque between the clutch plates can be suppressed.
[0018]
Therefore, when the wet friction clutch of the present invention is used as a vehicle coupling or a pilot clutch of a differential device, the four-wheel drive state is not inadvertently brought about, and traveling performance can be stabilized and driving can be performed. Loss is eliminated and fuel consumption can be improved.
[0019]
The Weisenberg effect is a physical fluid characteristic in which fluid (oil) is entangled and wound around a rotating part. Here, the end of the oil introduction path communicating with the oil chamber rotates in the oil chamber. This means that the oil is entangled and drawn into the oil introduction path.
[0025]
In addition, since the oil introduction path is provided along the radial direction of the clutch plate, the clutch plate adjacent to the oil introduction path at the time of differential rotation can be compared with the case where the oil introduction path is provided along the circumferential direction. The area in contact with the sliding portion can be widened.
[0026]
This is because the area of contact between the oil introduction path and the sliding portion during differential rotation of the clutch plate is determined by the radial dimension × rotation angle (rotational movement amount), so an oil introduction path is provided along the circumferential direction. Compared to the above, the one provided with the oil introduction path along the radial direction can set the radial dimension larger, so that the area can be increased.
[0027]
Thereby, the clutch plate can be effectively released, and the drag torque can be suppressed.
[0030]
  Claim2The invention of claim1The invention is described, wherein the edge of the oil introduction path is set to be thinner than the plate thickness of the general portion of the clutch plate, and a gap is formed between adjacent clutch plates,1'sThe same operation and effect as the configuration can be obtained.
[0031]
Also, since the edge of the oil introduction path is set to be thinner than the plate thickness of the general part of the clutch plate and a gap is formed between the adjacent clutch plates, the clutch plate adjacent to the edge of the oil introduction path Oil can be stored between the two and the amount of oil introduced between the clutch plates can be increased accordingly. Further, since the gap is formed, the gap serves as a guide for introducing oil between the clutch plates, and the oil is effectively introduced into the sliding portion between the clutch plates. Thereby, drag torque can be further suppressed.
[0041]
Also in this invention, the clutch plate of the wet friction clutch can be fastened in a state where the magnetic path generated by energizing the electromagnet is not short-circuited.
[0042]
In this invention, since the oil introduction path communicates with the gap portion of the clutch plate, the oil can be reliably introduced into the gap portion, and drag torque can be suppressed.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
  [Reference example]
  1-4, the present inventionReference exampleThe rear differential (differential device) 1 incorporating the above will be described.
[0045]
  FIG. 1 shows the present invention.Pertaining toA sectional view of a rear differential (rear differential device) incorporating an electromagnetic clutch is shown. FIG. 2 illustrates the present invention.Reference example3 is a front view showing a clutch plate (inner plate) of the wet friction clutch, FIG. 3 is a cross-sectional view of FIG. 1 taken along the line AA of FIG. 2, and FIG. 4 is a cross-sectional view of FIG. FIG. 2 shows a cross-sectional view of FIG. 1 along the part corresponding to the line.
[0046]
AlsoThe left and right directions are the vehicle using the rear differential 1 and the left and right directions in FIG. 1, and members without reference numerals are not shown.
[0047]
This vehicle is a four-wheel drive vehicle, and the rear differential 1 is disposed on the rear wheel side that is disconnected during two-wheel drive traveling.
[0048]
As shown in FIG. 1, the rear differential 1 includes a rotary case 3, a differential case 5, a bevel gear type differential mechanism 7, a clutch mechanism 9, and a rotor 11 constituting a part thereof.
[0049]
The rear differential 1 is accommodated in a differential carrier, the differential carrier is filled with oil, and an oil reservoir is provided in the lower part thereof.
[0050]
The rotating case 3 includes a ring gear 13 and a cylindrical member 15, and the cylindrical member 15 is processed by a press and welded to the ring gear 13.
[0051]
The ring gear 13 is supported on the differential case 5 by ball bearings 17 and 19 having a large diameter and a small diameter. Further, the ring gear 13 is a helical gear and meshes with a counterpart helical gear connected to the rear wheel side propeller shaft.
[0052]
As shown in FIG. 1, the rotating case 3 has a floating structure in which only torque transmission by the ring gear 13 is performed and the member supporting function is released.
[0053]
Also, the ring gear 13 applies a right meshing thrust force to the rotating case 3 when the vehicle is traveling forward, and a left meshing thrust force when traveling backward, due to its twist angle.
[0054]
The outer race 21 of the ball bearing 17 is positioned leftward by the step portion 23 of the ring gear 13, and the inner race 25 is positioned rightward by the pressure receiving member 27 and the step portion 28 of the differential case 5.
[0055]
The outer race 29 of the ball bearing 19 is positioned rightward by the step portion 31 of the ring gear 13, and the inner race 33 is positioned leftward by the snap ring 37 attached to the left boss portion 35 of the differential case 5. Has been. The snap ring 37 has a sufficient strength so that the snap ring 37 is broken when it receives a thrust force of a certain level or more while having a sufficient positioning function.
[0056]
The differential mechanism 7 includes a plurality of pinion shafts 39, a pinion gear 41, left and right side gears 43, 45, and the like.
[0057]
Each pinion shaft 39 is arranged radially from the rotation center axis of the differential case 5, and each tip engages with an engagement hole 47 of the differential case 5 and is prevented from coming off by a spring pin 49.
[0058]
The pinion gear 41 is supported on the pinion shaft 39, and a spherical washer 51 that receives the centrifugal force of the pinion gear 41 and the meshing reaction force with the side gears 43 and 45 is disposed between the differential case 5 and the pinion gear 41. ing.
[0059]
The side gears 43 and 45 are in mesh with the pinion gear 41, and thrust washers 53 that receive the meshing reaction force of the side gears 43 and 45 are arranged between the side gears 43 and 45 and the differential case 5.
[0060]
The side gears 43 and 45 are spline-connected to the left and right drive shafts, respectively, and each drive shaft penetrates to the outside from the left and right boss portions 35 and 55 of the differential case 5 and the differential carrier, and is connected to the left and right rear wheels via a joint. Has been.
[0061]
In the differential case 5, the left boss portion 35 is supported by a differential carrier by a ball bearing 74, and the right boss portion 55 is supported by a differential carrier via a ball bearing 75 and a core 73.
[0062]
The driving force of the engine (prime mover) that rotates the ring gear 13 is transmitted to the differential case 5 when the clutch mechanism 9 is connected as described below. The rotation of the differential case 5 is distributed from the pinion shaft 39 to the side gears 43 and 45 via the pinion gear 41, and further transmitted from the drive shaft to the left and right rear wheels, so that the vehicle enters a four-wheel drive state and escapes from a rough road. Performance, running ability, startability, acceleration, and stability of the vehicle body are greatly improved.
[0063]
Further, when a driving resistance difference occurs between the rear wheels on a rough road or the like, the driving force of the engine is differentially distributed to the left and right rear wheels by the rotation of the pinion gear 41.
[0064]
  The clutch mechanism 9 includes an electromagnet 57, a rotor 11, a multi-plate main clutch 59 and a pilot clutch (thisReference example(Wet friction clutch) 61, cam ring 63, ball cam 65 (cam mechanism), pressure plate 67, return spring 69, armature 71, controller, and the like.
[0065]
The core 73 of the electromagnet 57 is fixed to the differential carrier, and its lead wire is drawn out and connected to the controller.
[0066]
The rotor 11 is made of a magnetic material, is fixed to the outer periphery of the right boss portion 55 of the differential case by a snap ring 77, and is positioned in the axial direction. The rotor 11 also serves as the right side wall member of the rotating case 3.
[0067]
The main clutch 59 is disposed between the rotary case 3 (cylindrical member 15) and the differential case 5. The outer plate 79 is connected to a spline portion 81 provided on the inner periphery of the cylindrical member 15, and the inner plate 83 is connected to a spline portion 85 provided on the outer periphery of the differential case 5.
[0068]
The pilot clutch 61 is disposed between the cylindrical member 15 and the cam ring 63. The outer plate (clutch plate) 87 is connected to the spline portion 81 of the cylindrical member 15, and the inner plate (clutch plate) 89 is connected to the spline portion 91 provided on the outer periphery of the cam ring 63.
[0069]
Further, the spline portion 81 is processed at the same time when the cylindrical member 15 is pressed, and penetrates to the right end portion of the cylindrical member 15.
[0070]
The outer plate 87 and the inner plate 89 are alternately arranged in the axial direction, and the inner plate 89 faces the armature 71.
[0071]
The ball cam 65 is disposed between the cam ring 63 and the pressure plate 67. The pressure plate 67 is connected to the spline portion 85 of the differential case 5, and receives the cam thrust force of the ball cam 65 to press the main clutch 59 as described below.
[0072]
A thrust bearing 93 that receives the cam reaction force of the ball cam 65 is disposed between the cam ring 63 and the rotor 11.
[0073]
The return spring 69 is disposed between the pressure plate 67 and the differential case 5, and urges the pressure plate 67 in the connection release direction of the main clutch 59.
[0074]
The armature 71 is formed in a ring shape and is disposed between the pressure plate 67 and the pilot clutch 61 so as to be axially movable. The inner periphery of the armature 71 is centered by a stepped portion 94 of the pressure plate 67.
[0075]
The rotor 11, the outer plate 87 of the pilot clutch 61, the inner plate 89, and the armature 71 constitute a magnetic path of the electromagnet 57. When the electromagnet 57 is excited, a magnetic flux loop 95 is formed on the magnetic path.
[0076]
In addition, air gaps 97 and 99 having a predetermined interval are provided between the rotor 11 and the core 73 of the electromagnet 57 so as to become a part of the magnetic path. The rotor 11 includes a radially outer portion 101 and an inner portion 103, and the outer portion 101 and the inner portion 103 are connected by a bridge portion 107. The bridge portion 107 is thinned by forming recesses on both sides in the axial direction in order to enhance the magnetic short-circuit prevention effect.
[0077]
A washer 109 for improving the contact between the pilot clutch 61 and the rotor 11 is disposed between the rotor 11 and the pilot clutch 61. The washer 109 is attached to the rotor 11 by folding three claws 111 into a recess 113 formed on the outer periphery of the rotor 11.
[0078]
Further, there is a differential carrier between the inner periphery of the outer plate 87 of the pilot clutch 61 and the cam ring 63, between the outer periphery of the inner plate 89 and the rotating case 3, and between the rotating case 3 and the outer periphery of the armature 71. Oil chambers 115, 117, and 119 are formed which are immersed in the filled oil and have improved lubricity and cooling performance, such as the pilot clutch 61, the ball cam 65, and the main clutch 59. These oil chambers 115, 117, 119 further improves the magnetic short-circuit prevention effect.
[0079]
  Thus, the electromagnet 57, the pilot clutch 61, and the armature 71Reference exampleThe electromagnetic clutch is configured.
[0080]
The pilot clutch 61 is configured by alternately stacking three outer plates 87 and four inner plates 89, and is disposed between the rotor 11 (electromagnet 57) and the armature 71 in this stacked state. ing. Thus, the pilot clutch 61 is provided so as to be sandwiched between the electromagnet 57 and the armature 71.
[0081]
As shown in FIGS. 2 to 4, an engagement protrusion 135 that engages with the spline portion 89 of the cylindrical member 15 is formed on the outer diameter side of the outer plate 87, while a cam ring is formed on the inner diameter side of the inner plate 89. An engagement protrusion 137 that engages with 63 spline portions 91 is formed.
[0082]
The outer plate 87 and the inner plate 89 are formed with gap portions 131 and 133 that prevent a short circuit of the magnetic path, respectively. The gap portions 131 and 133 have an arc shape, and are formed at regular intervals in the circumferential direction of the clutch plates 87 and 89. Although the inner plate 89 is shown in FIG. 2, the gap portion 131 of the outer plate 87 is formed in substantially the same shape at a position facing the gap portion 133 of the inner plate 89.
[0083]
As a result, the aforementioned magnetic flux loop 95 is formed in the rotor 11, the outer plate 87 and inner plate 89 of the pilot clutch 61, and the armature 71 as shown in FIG. 3.
[0084]
On the other hand, an oil introduction passage 141 is formed in the inner plate 89 of the pilot clutch 61 as shown in FIG. A plurality of oil introduction paths 141 are provided in the circumferential direction so as to be positioned between the gap parts 133.
[0085]
  The oil introduction path 141 extends to the outer diameter side, and as shown in FIG. 4, its end communicates with the oil chambers 117 and 119.Reference exampleThe oil introduction path 141 is formed so that the outer diameter side of the inner plate 89 communicates with the oil chambers 117 and 119 and the inner diameter side communicates with the oil chamber 115.
[0086]
By forming such an oil introduction path 141 in the inner plate 89, when the outer plate 87 rotates, the oil existing in the oil chamber 117 between the inner plate 89 and the rotating case 3 is introduced into the oil introduction by the Weisenberg effect. Oil can be introduced from the path 141 to the sliding portions of the outer plate 87 and the inner plate 89. The oil introduced into the sliding portion acts to separate the adjacent outer plate 87 and inner plate 89 from each other. For this reason, the drag torque between the adjacent outer plate 87 and inner plate 89 can be suppressed.
[0087]
The controller performs excitation of the electromagnet 57, control of the excitation current, and excitation stop according to the road surface condition, traveling conditions such as start, acceleration, and turning of the vehicle, and steering conditions.
[0088]
When the electromagnet 57 is excited, the armature 71 is attracted and the pilot clutch 61 is pressed and fastened with the rotor 11.
[0089]
When the pilot clutch 61 is engaged, the driving force of the engine is applied to the ball cam 65 via the cam ring 63 connected to the rotating case 3 by the pilot clutch 61 and the pressure plate 67 on the differential case 5 side. The ball cam 65 amplifies this driving force and converts it into a cam thrust force, moves the pressure plate 67, and presses and fastens the main clutch 59 with the pressure receiving member 27.
[0090]
When the clutch mechanism 9 is thus connected, the rotation of the ring gear 13 is transmitted to the differential case 5 as described above, and the rotation is distributed to the left and right rear wheels by the differential mechanism 7 so that the vehicle is in a four-wheel drive state. Become.
[0091]
At this time, when the excitation current of the electromagnet 57 is controlled, the slip of the pilot clutch 61 is changed, the cam thrust force of the ball cam 65 is changed, and the driving force transmitted to the rear wheel side is controlled.
[0092]
When such driving force control is performed during turning, for example, turning performance and vehicle stability can be greatly improved.
[0093]
When the excitation of the electromagnet 57 is stopped, the pilot clutch 61 is released, the cam thrust force of the ball cam 65 disappears, the pressure plate 67 returns to the right by the urging force of the return spring 69, the main clutch 59 is released, and the clutch The connection of the mechanism 9 is released, and the vehicle enters a two-wheel drive state of front wheel drive.
[0094]
A spiral oil groove is provided on the inner periphery of the boss portions 35 and 55 of the differential case 5 through which the left and right drive shafts respectively penetrate. Further, the differential case 5 is provided with a large number of openings at a portion corresponding to the main clutch 59, and the rotary case 3 is provided with openings 121 and 121 at a portion corresponding to the pilot clutch 61.
[0095]
The oil chambers 115, 117, and 119 are provided in the vicinity of the pilot clutch 61 and the armature 71 arranged on the right end side of the rotating case 3 (cylindrical member 15).
[0096]
The lower part of the rotating case 3 is immersed in an oil reservoir provided in the differential carrier, and this oil flows from the oil chambers 115, 117, 119 to the sliding portion between the pilot clutch 61, the armature 71 and the pressure plate 67, and the ball cam. 65, the thrust bearing 93, the main clutch 59, the ball bearing 17, and the like are lubricated and cooled.
[0097]
The oil flows into the inside of the spiral oil groove as the differential case 5 rotates, lubricates and cools the meshing portions of the gears of the differential mechanism 7 and the spherical washer 51, and receives the centrifugal force as described above. It flows out from the opening to the main clutch 59 side, lubricates and cools the main clutch 59, ball bearing 17, ball cam 65, pilot clutch 61, thrust bearing 93, etc., and flows out from the oil chambers 115, 117, 119 and the openings 121, 121. Then return to the oil sump.
[0098]
The ball bearings 17 and 19 are also lubricated and cooled by oil splashed by the rotation of the ring gear 13.
[0099]
In addition, the electromagnet 57 is cooled by the oil to stabilize the characteristics, and the oil in the oil reservoir and the surrounding pilot clutch 61 and the ball cam 65 are heated by the heat of the electromagnet 57, and the warmed oil circulates. Each component is warmed to stabilize its function.
[0100]
Further, for example, when the gear box or the bearing is seized between the engine and the rear differential 1, the ring gear 13 of the rotating case 3 is rotated in a state of being rotated ahead of the counterpart helical gear by the traveling rotation of the rear wheel. Become.
[0101]
In this state, the direction of the torque transmitted between the ring gear 13 and the counterpart helical gear is the same as that of the reverse traveling, so that the rotating case 3 is moved to the left by the meshing of the helical gear as described above. Thrust force is generated.
[0102]
Further, as described above, since the strength of the snap ring 37 for positioning the ball bearing 19 is moderately adjusted, the snap ring 37 is broken when the thrust force is received through the ball bearing 19, and the rotating case 3. Moves to the left, and the outer plate 87 of the pilot clutch 61 is disengaged from the spline part 81 of the cylindrical member 15 by this movement.
[0103]
When the outer plate 87 is disengaged from the spline portion 81, the cam thrust force of the ball cam 65 disappears, the main clutch 59 is released, and the rear wheel side is disconnected, as in the case of releasing the pilot clutch 61.
[0104]
Therefore, even if seizure occurs on the engine side during traveling in the four-wheel drive state, the rear wheel side is automatically separated, so that the failure mode is improved to prevent the rotation of the rear wheels from being transmitted to the seizing part. .
[0105]
When the clutch mechanism 9 is disengaged (two-wheel drive state), the inner plate 89, pressure plate 67, armature 71, cam ring 63 (ball cam 65), thrust bearing 93, and rotor 11 of the pilot clutch 61 are the differential case. 5 and the outer plate 87 of the pilot clutch 61 rotates together with the rotating case 3.
[0106]
In such a configuration, when the outer plate 87 is disposed facing the armature 71, the driving force is transmitted from the outer plate 87 to the armature 71 by friction during the two-wheel drive traveling, and the rear wheel side is brought into a rotating state. Although there is a possibility that the fuel efficiency of the engine may be affected by the driving loss, in the rear differential 1, as described above, the inner plate 89 of the pilot clutch 61 is arranged to face the armature 71, and the driving force is transmitted by friction. Since it does not occur, the influence on the fuel consumption due to the rear driving loss of the rear wheels is prevented.
[0107]
Further, when the rotor 11 is supported on the rotating case 3 side, the relative rotation of the cam ring 63 on the differential case 5 side and the rotor 11 on the rotating case 3 side is applied to the thrust bearing 93 during the two-wheel drive traveling, which affects the durability. Although there is a fear, in the rear differential 1 in which the rotor 11 is supported on the differential case 5, the thrust bearing 93 is released from such relative rotation, and the influence on durability is prevented.
[0108]
Thus, the rear differential 1 is configured.
[0109]
As described above, the inner plate 89 of the pilot clutch 61 is provided with the oil introduction path 141 that guides oil to the sliding portions of the inner plate 89 and the outer plate 87, and the oil introduction path 141 includes the oil chamber 117, When the inner plate 89 rotates due to the communication with 119, oil is supplied to the oil introduction path 141 by the Weisenberg effect and the oil is guided to the sliding portion, so that the inner plate 89 and the outer plate 87 are introduced. Smoothly separated by oil. For this reason, drag torque can be suppressed.
[0110]
Since the drag torque can be suppressed, pilot torque is not generated in the pilot clutch 61, and inadvertent engagement of the main clutch 59 via the ball cam 65 due to the pilot torque can be prevented. Thus, since there is no inadvertent fastening of the main clutch 59, four-wheel drive is not performed during two-wheel drive. For this reason, while driving performance is stabilized, driving loss can be eliminated and fuel consumption can be improved.
[0111]
In addition, since a pressing state for fastening the main clutch 59 does not occur when it is unnecessary, an increase in temperature of the main clutch 59 can be suppressed, and durability of the main clutch 59 can be improved.
[0112]
Further, since the durability of the main clutch 59 is improved, a light and inexpensive material can be used for the main clutch 59.
[0113]
The Weisenberg effect is a physical fluid characteristic in which a fluid (oil) is entangled and wound around a rotating portion. Here, the end of the oil introduction path communicating with the oil chambers 117 and 119 is the oil chamber 117, By rotating within 119, it means that oil is entangled and drawn into the oil introduction path.
[0114]
  Also especially thisReference exampleThen, since the oil introduction path 141 is provided along the radial direction of the inner plate 89, the oil introduction path 141 is adjacent to the oil introduction path 141 at the time of differential rotation as compared with the case where the oil introduction path is provided along the circumferential direction. The area in contact with the sliding portion of the outer plate 87 can be widened.
[0115]
This is because the area S where the oil introduction path 141 and the sliding portion contact at the time of differential rotation between the inner plate 89 and the outer plate 87 is determined by the radial dimension L × the rotation angle θ (rotational movement amount). Compared with the oil introduction path 141 along the circumferential direction (radial dimension L1), the one with the oil introduction path 141 along the radial direction (radial dimension L2) has a larger radial dimension. L1 <L2) The area S can be increased (S1 <S2) by the amount that can be set.
[0116]
Here, it demonstrates concretely with FIG. 5 which showed some virtual inner plates 89. FIG. Suppose that there is an oil introduction path 141 ′ provided along the circumferential direction as shown in FIG. At this time, assuming that the radial dimension of the oil introduction path is L1 and the relative rotation angle between the inner plate 89 and the outer plate 87 is θ, the area S1 where the oil introduction path 141 ′ and the sliding portion are in contact with each other is indicated by the hatched portion in the figure. (Area S1).
[0117]
  On the other hand, as shown in FIG. 5B, the oil introduction path 141 is provided along the radial direction.Reference exampleIn the case of the inner plate 89, when the radial dimension of the oil introduction path is L2 and the relative rotation angle is θ, the area S2 in contact with the oil introduction path 141 and the sliding portion is a region (area S2 indicated by a hatched portion in the figure). It is also clear from the figure that it is far wider than the region (area S1) in which the oil introduction path 141 ′ is provided along the circumferential direction.
[0118]
Thereby, the clutch plate can be effectively released, and the drag torque can be suppressed.
[0119]
Further, the oil introduction path 141 communicates from the oil chambers 117 and 119 on the outer diameter side of the inner plate 89 and the outer plate 87 to the oil chamber 115 on the inner diameter side, so that the oil chamber on the outer diameter side of the oil introduction path 141 is provided. The excess oil can be discharged into the oil chamber 115 on the inner diameter side while the oil is drawn into the oil introduction path 141 from the 117 and 119 by the Weisenberg effect and introduced into the sliding portion of the outer plate 87. Thereby, the oil flow in the oil introduction path 141 is smoothly performed, the inner plate 89 and the outer plate 87 can be separated more smoothly, and drag torque can be suppressed.
[0120]
Moreover, since the oil introduction path 141 is provided between the gap portions 133 and 133, the rigidity of the clutch plate can be ensured.
[0121]
  In addition, thisReference exampleIn the above example, the oil introduction path 141 is provided on the inner plate 89. However, the present invention is not limited to this, and the oil introduction path 141 is provided on the outer plate 87 or on both the inner plate 89 and the outer plate 87. May be.
[0122]
14 and 15 are graphs comparing the performance of an electromagnetic clutch in which the wet friction clutch of the present invention is applied to the pilot clutch 61. FIG.
[0123]
FIG. 14 shows the performance of the drag torque of the pilot clutch 61. When the solid line A is provided with the oil introduction path in both the inner plate 89 and the outer plate 87, the chain line B is the oil introduction path only in the inner plate 89. When provided, the broken line C indicates a conventional case in which no oil introduction path is provided.
[0124]
Thus, it can be seen that both the solid line A and the chain line B have a smaller drag torque than the conventional broken line C.
[0125]
FIG. 15 is a plot of changes in the temperature of the main clutch 59. Each of the lines A, B, and C is the same as 109.
[0126]
Thus, both the solid line A and the chain line B have a smaller temperature rise than the conventional broken line C, and the occurrence of pressing when the main clutch 59 is not required based on the drag torque of the pilot clutch 61 is suppressed. I understand.
[0127]
  [No.1Embodiment]
  6 through 91An embodiment will be described.
[0128]
  FIG.1The front view which shows the clutch board (outer plate) of the wet friction clutch of embodiment, FIG. 7: has shown sectional drawing of FIG. 1 along the part applicable to CC line of FIG.
[0129]
  This first1The embodiment is,in frontDescriptiveReference exampleAnd the oil introduction path have different shapes. The other parts are denoted by the same reference numerals, and redundant description is omitted.
[0130]
6 and 7 show the outer plate 87 of the pilot clutch 61, and an engagement protrusion 135 that engages with the spline portion 81 of the cylindrical member 15 is formed on the outer diameter side. Further, arc-shaped gap portions 131 that prevent a short circuit of the magnetic path of the electromagnet 57 are formed at regular intervals in the circumferential direction.
[0131]
In some of the gap portions 131, an oil introduction path 143 is formed in a communicating state. The oil introduction path 143 extends from the gap portion 131 toward the outside in the radial direction, and the extending tip portion is located outside the sliding portion of the inner plate 89. That is, 145 indicated by a broken line is the tip of the sliding portion of the inner plate 89, and the oil introduction path 143 extends to the outside of the sliding portion tip 145 and communicates with the oil chambers 117 and 119.
[0132]
8 and 9, the oil introduction path 143 is formed so as to pass through the thickness direction of the inner plate 89 (or the outer plate 87). A gap is formed between the adjacent outer plates 87 set to be thinner than the thickness of the general portion of the plate 89. In this way, by forming a gap between the edge of the oil introduction path 143 and the adjacent outer plate 87, oil can be stored in the gap portion, and accordingly, the inner plate 89 and the outer plate 87 The amount of oil introduced in between can be increased. Further, since the gap is formed, the gap serves as a guide for introducing oil between the inner plate 89 and the outer plate 87, and the oil is effectively introduced between the inner plate 89 and the outer plate 87. . Thereby, drag torque can be further suppressed.
[0133]
In FIG. 9A, the edge portion of the oil introduction path 143 and the outer surface 89 a of the inner plate 89 are connected by the slope portion 153. Since the oil flows through the slope portion 153 and enters the oil introduction path 143, the oil can be smoothly introduced into the sliding portion between the inner plate 89 and the outer plate 87, thereby suppressing drag torque. Can do.
[0134]
FIG. 9B shows an example of a different shape of the oil introduction path 143, and the edge portions 155 at both ends are arcuate. Thus, by making the edge part 155 of the oil introduction path 143 into an arc shape (in particular, in this embodiment, the edge part is punched in an arc shape in the plate thickness direction), the oil flows smoothly. Can do. For this reason, oil can be smoothly introduced into the sliding portion between the inner plate 89 and the outer plate 87, and drag torque can be suppressed.
[0135]
In such an oil introduction path 143 of the outer plate 87, since the oil in the oil chamber 117 is guided to the sliding portion with the inner plate 89, the outer plate 87 and the inner plate 89 can be separated.
[0136]
Particularly in this embodiment, since the oil introduction path 143 communicates with the gap portion 131, oil can be introduced into the gap portion 131, and the amount of oil introduced can be increased. And the inner plate 89 can be reliably separated. As a result, the drag torque can be suppressed, the four-wheel drive state is not inadvertently caused, the running performance is stabilized, the driving loss can be eliminated, the fuel consumption can be improved, and the main clutch can be improved. The temperature rise of 59 can be suppressed, and its durability can be improved.
[0137]
Further, the outer plate 87 of FIG. 6 and the inner plate 89 having the structure shown in FIG. 2 can be used in combination. In the inner plate 89 of FIG. 2, a plurality of oil introduction paths 141 are formed along the radial direction, and oil can be introduced from the inner plate 89 into the sliding portion with the outer plate 87. Thus, in the structure in which oil is introduced from both the inner plate 89 and the outer plate 87, a large amount of oil can be introduced, and the inner plate 89 and the outer plate 87 can be smoothly separated. For this reason, drag torque can be suppressed.
[0138]
  [No.2Embodiment]
  10 and 11 show the first2FIG. 10 shows an embodiment of the present invention.2The front view which shows the clutch board (inner plate) of the wet friction clutch of embodiment, FIG. 11: has shown sectional drawing of FIG. 1 along the part applicable to the DD line of FIG.
[0139]
  This first2The embodiment is,in frontDescriptiveReference exampleAnd second1An example in which the shape of the oil introduction path is different from that of the embodiment is shown, and the same reference numerals are given to the other parts, and the overlapping description is omitted.
[0140]
  This first2In the embodiment, as shown in FIG. 10, the oil introduction path 149 is formed in the inner plate 89 of the pilot clutch 61, and the oil introduction path 143 is formed in the inner plate 87.1It is a modification of embodiment.
[0141]
  Therefore, if the cross-sectional shape of the oil introduction path 149 is the same as that of the oil introduction path 143, the above-mentioned first1The same operation and effect as the embodiment can be obtained.
[0142]
The oil introduction path 149 is formed so as to communicate with a part of the gap portion 133 formed in the inner plate 89. The oil introduction path 149 is formed so as to extend from the gap portion 133 toward the inner diameter side. By extending in such a direction, oil can be reliably introduced into the sliding portion of the outer plate 87.
[0143]
Moreover, the pilot clutch 61 can also be comprised combining with the outer plate 87 of FIG. 6, and sectional drawing in this case is shown in FIG.
[0144]
Thus, the oil introduction passage 143 provided in the outer plate 87 of the pilot clutch 61 and the oil introduction passage 149 provided in the inner plate 89 communicate with the outer diameter side oil chambers 117 and 119 and the inner diameter side oil chamber 115. As a result, oil is drawn into the oil introduction passage 143 from the oil chambers 117 and 119 on the outer diameter side of the oil introduction passage 143 by the Weisenberg effect, and the oil is introduced into the sliding portion of the outer plate 87 and the gap portions 131 and 133. The oil can be supplied to the oil introduction passage 149 through the oil introduction passage 149, the oil can be introduced into the sliding portion of the inner plate 89 through the oil introduction passage 149, and the excess oil can be discharged into the oil chamber 115 on the inner diameter side. As a result, the oil flows smoothly through the oil introduction paths 143 and 149, the inner plate 89 and the outer plate 87 can be separated more smoothly, and drag torque can be suppressed.
[0145]
  [Other reference examples]
  FIG.Moisture of other reference examplesIt is a front view which shows the clutch board (inner plate) of a type | formula friction clutch. In addition, thisOther reference examplesThe aboveReference example, first and second embodimentsAnd the oil introduction path have different shapes. The other parts are denoted by the same reference numerals, and redundant description is omitted.
[0146]
FIG. 13 shows an inner plate 89 of the pilot clutch 61, and a plurality of oil introduction grooves 147 are formed in the circumferential direction between gap portions 133 formed at regular intervals in the circumferential direction.
[0147]
The oil introduction groove 147 is formed so as to communicate from the outer diameter side to the inner diameter side of the inner plate 89. The oil introduction path 147 has a cross shape in which a part of the gap portion 133 is integrally formed. For this reason, the oil introduction path 147 extends in the radial direction and also in the circumferential direction. Further, the oil introduction path 147 extends outward from the sliding portion where the outer plate 87 slides with the inner plate 89. In such an oil introduction path 147, since the oil in the oil chamber 117 is guided to the sliding portion with the outer plate 87, the outer plate 87 and the inner plate 89 can be separated. For this reason, drag torque can be suppressed.
[0148]
In particular, since the oil introduction path 147 extends in the circumferential direction, the amount of oil introduced can be increased, and the outer plate 87 and the inner plate 89 can be reliably separated accordingly.
[0149]
  thisReference exampleIn this case, the pilot clutch 61 can be configured by a combination with the outer plate 87 of FIG. In the outer plate 87 of FIG. 6, the oil introduction path 143 is formed so as to communicate with the gap portion 131. By combining the outer plate 87, oil is supplied from both the inner plate 89 and the outer plate 87. Since a large amount of oil can be introduced, the inner plate 89 and the outer plate 87 can be smoothly separated.
[0150]
【The invention's effect】
In the first aspect of the present invention, the oil is drawn into the oil introduction path provided on one side of the clutch plate by the Weisenberg effect, and the oil is guided to the sliding portion of the clutch plate, so that the adjacent clutch plates are separated smoothly. And drag torque between the clutch plates can be suppressed. Therefore, the vehicle is not inadvertently brought into the four-wheel drive state, the running performance can be stabilized, the driving loss can be eliminated, and the fuel consumption can be improved.
[0152]
  Also thisIn the inventionTheSince the oil introduction path is provided along the radial direction of the clutch plate, the sliding of the clutch plate adjacent to the oil introduction path is different during differential rotation compared to the case where the oil introduction path is provided along the circumferential direction. The area in contact with the part can be widened.
  In the present invention, the oil introduction path communicates with the gap portion of the clutch plate, so that the oil can be reliably introduced into the gap portion.
[0153]
Thereby, the clutch plate can be effectively released, and the drag torque can be suppressed.
[0155]
  Claim2In the invention of claim1 andIn addition to having the same effect, oil can be stored in the gap portion, and the amount of oil introduced between the clutch plates can be increased accordingly. Further, since the gap is formed, the gap serves as a guide for introducing oil between the clutch plates, and the oil is effectively introduced into the sliding surface between the clutch plates. Thereby, drag torque can be further suppressed.
[Brief description of the drawings]
[Figure 1]Reference exampleIt is sectional drawing of the rear differential in which was incorporated.
[Figure 2]Reference exampleIt is a front view of an inner plate.
3 is an enlarged cross-sectional view of a main part of FIG. 1 taken along line AA of FIG.
4 is an enlarged cross-sectional view of a main part of FIG. 1 taken along the line BB of FIG. 2;
FIG. 5 is an explanatory diagram of an area where an oil introduction path and a sliding portion are in contact with each other.
FIG. 61It is a front view of the outer plate of an embodiment.
7 is an enlarged cross-sectional view of a main part of FIG. 1 taken along the line CC of FIG. 6;
FIG. 81It is an enlarged view of the principal part of embodiment.
FIG. 91It is an expanded sectional view of the important section of an embodiment.
FIG. 102It is a front view of the inner plate of an embodiment.
11 is an enlarged cross-sectional view of the main part of FIG. 1 taken along the line DD of FIG. 10;
FIG. 121Embodiment and first2It is an expanded sectional view of the principal part of FIG. 1 which combined embodiment.
FIG. 13Other reference examplesIt is a front view of an inner plate.
FIG. 14 is a characteristic diagram showing drag torque.
FIG. 15 is a characteristic diagram showing a temperature change of the main clutch.
FIG. 16 is a cross-sectional view of a coupling using a conventional structure.
[Explanation of symbols]
  87 Outer plate
  89 Inner plate
  115, 117, 119 Oil chamber
  131, 133 Gap part
  141, 143, 147, 149, 151 Oil introduction path

Claims (2)

A wet friction clutch disposed between the torque transmission member on one side and the other side and fastened by excitation of an electromagnet ,
The wet friction clutch has a sliding portion that is overlapped so as to slide relative to each other and forms a magnetic path by excitation of the electromagnet, and is formed at regular intervals in the circumferential direction to prevent a short circuit of the magnetic path. The outer and inner clutch plates connected to each of the torque transmission members on the one side and the other side through the respective engaging projections . oil introduction passage for guiding oIL is provided on at least one of the sliding surfaces of the outer and inner clutch plates that are adjacent,
The oil introduction path communicates with the arc-shaped gap portion and communicates with an oil chamber provided with a non-opening tip portion in the radial direction on the engagement projection side. Wet friction clutch. The wet friction clutch according to claim 1, wherein an edge of the oil introduction path is set to be thinner than a plate thickness of a general portion of the clutch plate and a gap is formed between adjacent clutch plates. Wet friction clutch.

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