JP5948956B2 - Vehicle power transmission device - Google Patents

Description

  The present invention relates to a power transmission device for a vehicle provided with a dry friction clutch, and more particularly to a dust discharge structure for the dry friction clutch.

  In recent years, a dry friction clutch has been adopted as a clutch for switching between connection and disconnection of an internal combustion engine and a motor in a hybrid vehicle. Such a dry friction clutch has a lower drag resistance when the clutch is released than a wet friction clutch that uses a highly viscous hydraulic oil, and therefore can reduce friction loss during motor travel when the engine is disconnected.

  In such a dry friction clutch, it is necessary to discharge dust such as splash of grease and wear powder of a friction material (facing lining) to the outside. As such a dust discharge structure, for example, the one described in Patent Document 1 uses a pressure difference generated between the inner peripheral side and the outer peripheral side of the dry friction clutch by the action of the centrifugal fan accompanying the rotation of the dry friction clutch itself. The dust in the dry friction clutch is guided radially outward and discharged to the outside.

JP 2010-242824 A

  However, in the dust discharge structure utilizing the centrifugal action by the rotation of the dry friction clutch itself, the radial dimension of the facing portion of the clutch is relatively short, or depending on the material of the friction material, the operation pattern, etc. In addition, a sufficient air flow for discharging dust cannot be obtained, and the desired dust discharge performance may not be obtained, and further improvement has been desired.

  The present invention has been made in view of such problems, and provides a novel vehicle power transmission device that can enhance the flow of air flowing through a dry friction clutch and improve dust discharge performance. The purpose is that.

  Therefore, in the present invention, the air flow that flows through the dry friction clutch is made by using a rotating body such as a damper or a flywheel that is arranged coaxially and spaced apart in the axial direction of the dry friction clutch. Strengthened. Specifically, the air that flows in the vicinity of the outer peripheral portion of the rotating body by the rotation of the rotating body is sent to the vicinity of the engaging portion between the clutch hub and the hub side friction plate in the dry friction clutch.

  In the vicinity of the rotating body, a pressure difference is generated in the radial direction due to the action of the centrifugal fan accompanying the rotation of the rotating body, and the pressure at the outer peripheral portion becomes higher than the inner peripheral portion. The high-pressure air that flows in the vicinity of the outer periphery of the rotating body is sent to the vicinity of the engagement portion between the clutch hub and the hub side friction plate in the dry friction clutch, so that the air flowing through the dry friction clutch In particular, in the dry friction clutch, the air flowing radially outward from the engagement portion between the inner peripheral side clutch hub and the hub side friction plate toward the outer periphery side clutch drum and the drum side friction plate is engaged. The flow can be strengthened and the dust discharge performance can be improved.

Sectional drawing of the part corresponded to the area | region (alpha) of FIG. 3 which shows the principal part of the power transmission device with which one Example of this invention was applied. Explanatory drawing which shows typically the intake duct member and exhaust duct member which were attached to the housing cover. The block diagram which shows simply the power transmission device of the hybrid vehicle to which the said Example is applied.

  Hereinafter, the present invention will be described with reference to illustrated embodiments. FIG. 3 schematically shows a power train of a hybrid vehicle to which a power transmission device according to an embodiment of the present invention is applied. This vehicle is a front-wheel drive type 1-motor 2-clutch parallel hybrid vehicle, and an engine 1 and a motor generator 2 are used together as a vehicle drive source. The engine 1 is a well-known spark ignition gasoline engine or compression self-ignition diesel engine. The motor generator 2 has both a function as an electric motor that rotates by receiving electric power supplied from a battery (not shown) and a function as a generator that regenerates rotational power and fills the battery.

  A damper 3 as a power transmission buffer member that absorbs vibration of the engine 1 is provided between the engine 1 and the motor generator 2, and the first is used to switch connection and disconnection of power transmission between the engine 1 and the motor generator 2. A clutch 4 is provided. The motor generator 2 is connected to a pair of drive wheels 7 via an automatic transmission 5 comprising a belt-type continuously variable transmission and a differential gear 6, and a second clutch is provided between the motor generator 2 and the automatic transmission 5. 8 is interposed. The second clutch 8 may be interposed between the automatic transmission 5 and the differential gear 6, and when the automatic transmission 5 is a stepped type, The clutch may also be used as the second clutch 8.

  The first clutch 4 is interposed between a clutch input shaft 4A connected to the damper 3 and a clutch output shaft 4B connected to the motor generator 2, and switches between disconnection and connection of both. For example, in the “electric vehicle running mode” in which only the motor generator 2 is the drive source, the first clutch 4 is released and the engine 1 is disconnected, while the engine 1 and the motor generator 2 are used together as the drive source. In “travel mode”, the first clutch 4 is engaged and the engine 1 and the motor generator 2 are connected. The second clutch 8 is engaged or semi-engaged during traveling, and is released when the shift range is the N (neutral) range or the P (parking) range.

  1 is a cross-sectional view of a portion corresponding to a region α in FIG. The damper 3 has a substantially disk shape arranged coaxially with the clutch input shaft 4A, and a plurality of damper springs 3A for absorbing vibration are provided along the circumferential direction, and the engine 1 is connected via the damper springs 3A. Rotational power is transmitted to the clutch input shaft 4A. The clutch side plate 3B of the damper 3 is coupled to the clutch input shaft 4A, and rotates around the shaft integrally with the clutch input shaft 4A.

  The motor generator 2 and the first clutch 4 are accommodated in a clutch housing 11 made of a cast metal part adjacent to the damper 3 with a predetermined gap in the axial direction. The clutch housing 11 is roughly constituted by a housing body 12 and a housing cover 13 which is attached to an opening of the housing body 12 on the damper 3 side and closes the opening, and is supported outside the vehicle body. The engine block 10 is fixed via a seal member 14 or the like. In the clutch housing 11, the clutch input shaft 4 </ b> A and the clutch output shaft 4 </ b> B are rotatably penetrated and supported via bearings 15 and 16.

  The motor generator 2 is a synchronous AC motor, and includes a rotor 18 in which a permanent magnet 17 is embedded, a stator 20 disposed on the rotor 18 via an air gap 19, and a stator coil 21 wound around the stator 20. And have. The stator 20 is fixed to the housing body 12 described above. The rotor 18 is connected to the clutch output shaft 4B via a clutch drum 23 and a ring member 24, which will be described later, and rotates around the shaft integrally with the clutch output shaft 4B. The first clutch 4 is accommodated in the inner peripheral side of the motor generator 2, specifically, in the radial gap between the rotor 18 of the motor generator 2 and the clutch input shaft 4 </ b> A.

  The first clutch 4 is a normally open dry multi-plate friction clutch that is a main part of the present embodiment, and is hereinafter referred to as a dry clutch 4. The dry clutch 4 is fixed to the outer periphery of the clutch input shaft 4A, is provided with a clutch hub 22 that rotates integrally with the clutch input shaft 4A, and is provided coaxially and relatively rotatably on the outer periphery side of the clutch hub 22; A clutch drum 23 that is fixed to the clutch output shaft 4B via the ring member 24 and rotates integrally with the clutch output shaft 4B is provided. The rotor 18 of the motor generator 2 described above is fixed to the outer peripheral side of the clutch drum 23.

  A plurality of ring-shaped hub-side friction plates 25 extending radially outward are attached to the outer peripheral side of the clutch hub 22 so as to be movable in the axial direction. Specifically, a plurality of spline grooves 22A extending in the axial direction are formed on the outer periphery of the clutch hub 22, and a plurality of spline teeth formed on the inner periphery of each hub side friction plate 25 are splined in the spline grooves 22A. By engaging, each hub-side friction plate 25 is supported in a state where it can move in the axial direction with respect to the clutch hub 22 and the movement in the circumferential direction is restricted.

  A plurality of ring-shaped drum side friction plates 26 extending radially inward are attached to the inner peripheral side of the clutch drum 23 so as to be movable in the axial direction. Specifically, a spline groove 23A extending in the axial direction is formed on the inner periphery of the clutch drum 23, and spline teeth formed on the outer periphery of the drum side friction plate 26 are spline engaged with the spline groove 23A. Each drum-side friction plate 26 is supported in a state where it can move in the axial direction with respect to the clutch drum 23 and the movement in the circumferential direction is restricted.

  The hub-side friction plates 25 and the drum-side friction plates 26 are alternately arranged in the axial direction, and ring-shaped friction materials 27 serving as facing linings are interposed between the facing surfaces. The hub-side friction plate 25 and the drum-side friction plate 26 are driven in the axial direction by a hydraulic actuator to be released or fastened to each other, thereby interrupting and connecting the power transmission between the clutch input shaft 4A and the clutch output shaft 4B. Can be switched. The hydraulic actuator includes a hydraulic piston 28 that is operated by hydraulic pressure supplied from a hydraulic circuit (not shown). By supplying hydraulic pressure to the hydraulic piston 28, the hydraulic piston 28 operates in the right direction in FIG. 1 against the spring force of the return spring 29, and the hub-side friction plate 25 and the drum-side friction via the friction material 27. The plate 26 is brought into pressure contact, and the clutch is engaged. On the other hand, when the hydraulic pressure is released, the hydraulic piston 28 slides to the left in the drawing by the spring force of the return spring 29, the hub side friction plate 25 and the drum side friction plate 26 are separated, and the clutch is released.

  A clutch chamber 30 in which the dry clutch 4 is accommodated, a wet chamber 31 to which hydraulic oil for hydraulic control is supplied, and a motor chamber 32 in which the motor generator 2 is accommodated are formed in the clutch housing 11. A plurality of seal members 33 to 37 are provided so that hydraulic oil, dust or the like does not enter or move between these chambers 30 to 32. In particular, the clutch chamber 30 is a sealed space partitioned from the wet chamber 31 by two oil seals 33 and 34 and partitioned from the motor chamber 32 by a seal member 35.

  Next, a basic dust discharge structure of the dry clutch 4 will be described with reference to FIG. A substantially disc-shaped housing cover 13 constituting one wall portion of the clutch housing 11 is interposed in the axial gap 40 between the damper 3 rotating around the shaft and the dry clutch 4. In the drawing, an intake hole 41 and an exhaust hole 42, one end of which communicates with the clutch chamber 30, are formed to penetrate in the axial direction. The intake hole 41 opens in the vicinity of the engagement portion between the spline groove 22A of the clutch hub 22 and the hub side friction plate 25, that is, the portion on the inner peripheral side with respect to the friction material 27, and the exhaust hole 42 is formed as described above. It is radially outward from the intake hole 41 and opens in the vicinity of the engagement portion between the spline groove 23A of the clutch drum 23 and the drum side friction plate 26, that is, the outer peripheral side portion of the friction material 27.

  Due to the action of the centrifugal fan accompanying the rotation of the dry clutch 4, a pressure difference is produced in the radial direction in the clutch chamber 30, that is, the pressure inside the radial direction in which the intake holes 41 are formed is slightly lower than the atmospheric pressure. On the other hand, the pressure on the radially outer side where the exhaust hole 42 is formed becomes a slightly positive pressure slightly higher than the atmospheric pressure, and due to this radial pressure difference, as shown by arrows K1 to K3 in FIG. Is introduced into the clutch chamber 30 through the intake hole 41 (K1), flows radially outward in the dry clutch 4 (K2), and is then discharged from the exhaust hole 42 to the outside of the clutch chamber 30 ( K3). More specifically, the air supplied into the clutch chamber 30 through the intake hole 41 flows along the axial direction through the clearance of the spline engaging portion between the clutch hub 22 and the hub side friction plate 25 to the left side in FIG. After that, a gap between the hub side friction plate 25 and the drum side friction plate 26 in which the friction material 27 is interposed flows along the radial direction to the upper side in FIG. After flowing through the gap of the spline engaging portion with the plate 26 to the right side in FIG. 1 along the axial direction, the air is discharged to the outside through the exhaust hole 42. Thus, when air flows through the dry clutch 4, dust such as wear powder in the dry clutch 4 flows out together and is discharged from the exhaust hole 42 to the outside along the air flow.

  As described in Japanese Patent Application Laid-Open No. 2010-242824, guide grooves extending in the radial direction in the friction material 27 and the friction plates 25 and 26 so as to promote the flow of air and dust in the dry clutch 4. In addition, a guide hole penetrating in the axial direction may be provided in the vicinity of the spline engaging portion of the friction plates 25 and 26.

  However, depending on the material of the friction material 27 of the dry clutch 4, the operation pattern, and the like, there is a possibility that the air flows K <b> 1 to K <b> 3 in the clutch chamber 30 cannot be sufficiently obtained and the desired dust discharge performance cannot be obtained. is there. In particular, as shown in FIG. 1, in the structure in which the dry clutch 4 is disposed in the narrow space inside the motor generator 2 in the radial direction, the radial dimension of the facing portion of the dry clutch 4 is inevitably short. It is difficult to ensure a sufficient radial pressure difference, and the air flows K1 to K3 tend to be weak.

  Therefore, in this embodiment, in order to reinforce the air flows K1 to K3 in the clutch chamber 30 described above, a tubular intake duct member 43 and an exhaust duct member 44 are attached to the side surface of the housing cover 13 on the damper 3 side. It has been. The intake duct member 43 and the exhaust duct member 44 are positioned on the upper side in the vertical direction from the hole 13A in the central portion of the shaft of the housing cover 13 through which the clutch input shaft 4A passes in the vehicle-mounted state shown in FIGS. Thus, the housing cover 13 is fixed using a fixing tool such as a bolt or an adhesive.

  The internal passage of the intake duct member 43 communicates at one end with the intake hole 41 of the housing cover 13 and constitutes a series of tubular intake ducts 45 through which air flows together with the intake hole 41. The intake duct 45 extends in the radial direction along the housing cover 13 while passing through the housing cover 13 in the axial direction at a portion of the intake hole 41, and is an intake duct inlet that is an end portion on the radially outer side. 46 opens in the vicinity of the outer peripheral portion of the damper 3 as a rotating body. Specifically, the intake duct inlet 46 is disposed in the vicinity of the outermost diameter portion of the damper 3 adjacent to the inner wall surface of the engine block 10, further radially outward than the dry clutch 4 and the stator 20 of the motor generator 2. . In addition, the intake duct inlet 46 opens to the side so as to face the rotational direction β of the damper 3. That is, a portion 47 of the intake duct 45 in the vicinity of the intake duct inlet 46 extends in the circumferential direction with the intake duct inlet 46 being upstream of the damper rotation direction β. On the other hand, the intake hole 41, which is the radially inner end of the intake duct 45, opens near the engagement portion between the clutch hub 22 and the hub-side friction plate 25. Therefore, the radial dimension of the intake duct 45 is much longer than the radial dimension of the facing portion of the dry clutch 4.

  The internal passage of the exhaust duct member 44 communicates with the exhaust hole 42 of the housing cover 13 at one end, and constitutes a series of tubular exhaust ducts 48 through which air flows. The exhaust duct 48 extends in the radial direction along the housing cover 13 while passing through the housing cover 13 in the axial direction at the portion of the exhaust hole 42, and is an exhaust hole that is an end portion on the radially outer side. As described above, 42 is disposed in the vicinity of the spline engaging portion between the spline groove 23A of the clutch drum 23 and the drum side friction plate 26. On the other hand, the exhaust duct outlet 49, which is the radially inner end of the exhaust duct 48, is located at least radially inward of the exhaust hole 42, and opens near the axial center of the damper 3. In addition, the exhaust duct outlet 49 is opened downward so that the opening direction is along the rotational direction β of the damper 3. That is, a portion 50 of the exhaust duct 48 in the vicinity of the exhaust duct outlet 49 extends in the circumferential direction with the exhaust duct outlet 49 being downstream of the damper rotation direction β.

  As shown in FIG. 2, due to the action of the centrifugal fan by the damper 3 rotating around the axis, a pressure difference is generated in the radial direction in the vicinity of the damper 3, as in the case of the dry clutch 4. The pressure in the vicinity of the outer periphery of the damper where the inlet 46 is opened is higher than the atmospheric pressure. In particular, in this embodiment, since the damper 3 is a large rotating body whose radial dimension is much larger than that of the dry clutch 4, the positive pressure at the outer peripheral portion of the damper 3 is weak positive pressure at the outer peripheral portion of the dry clutch 4. Much bigger than. On the other hand, the intake hole 41 at the other end of the intake duct 45 communicates and opens at the engagement portion between the clutch hub 22 and the hub-side friction plate 25, that is, the inner periphery of the weak negative pressure in the clutch chamber 30. Therefore, due to the large pressure difference generated at both ends of the intake duct 45, the air flow K4 in the intake duct 45 from the inlet 46 toward the intake hole 41 is strengthened, and the flow rate and flow velocity increase. As a result, the air flow K1 fed into the clutch chamber 30 via the intake duct 45, and consequently the air flow K2 flowing in the dry clutch 4 in the radial direction, is greatly enhanced to improve the dust discharge performance. be able to.

  Further, due to the action of the centrifugal fan by the damper 3 rotating around the axis, the vicinity of the axial center portion of the damper 3 where the outlet 49 of the exhaust duct 48 opens has a negative pressure lower than the atmospheric pressure. On the other hand, the exhaust hole 42, which is one end of the exhaust duct 48, communicates and opens at an engagement portion between the clutch drum 23 and the drum-side friction plate 26, that is, an outer peripheral portion of weak positive pressure in the clutch chamber 30. Therefore, a large pressure difference generated at both ends of the exhaust duct 48 enhances the air flow K5 in the exhaust duct 48 from the exhaust hole 42 to the outlet 49, and the flow rate and flow velocity increase. As a result, the air flow K3 discharged from the clutch chamber 30 through the exhaust hole 42, and hence the air flow K2 flowing in the dry clutch 4 in the radial direction can be strengthened to further improve the dust discharge performance. .

  Further, as described above, the intake duct inlet 46 is opened so as to oppose the damper rotation direction β, that is, the portion 47 in the vicinity of the inlet of the intake duct 45 is surrounded by the inlet 46 as the upstream side of the damper rotation direction β. A passage shape extending in the direction is formed. Therefore, the air swirling in the rotational direction β with the rotation of the damper 3 is smoothly pushed into the intake duct 45 from the inlet 46, and the air flow K4 flowing into the intake duct 45 can be further enhanced. .

  Further, the exhaust duct outlet 49 is opened so as to extend along the damper rotation direction β, that is, the portion 50 in the vicinity of the outlet of the exhaust duct 48 has a passage shape extending in the circumferential direction with the outlet 49 being downstream of the damper rotation direction β. There is no. For this reason, air is smoothly sucked out from the exhaust duct 48 through the outlet 49 by the flow of air swirling in the rotational direction β as the damper 3 rotates, and the flow of air discharged from the exhaust duct 48 K5 can be further strengthened.

  In addition, since the intake duct 45 and the exhaust duct 48 are disposed vertically above the clutch input shaft 4A and the clutch output shaft 4B in the vehicle-mounted state, the intake duct 45 is maintained until the water level becomes high even if the vehicle is submerged. In addition, the exhaust duct 48 is not submerged, and rain water or the like can be prevented from entering the clutch chamber 30 of the clutch housing 11 via the intake duct 45 or the exhaust duct 48.

  In addition, the intake duct inlet 46 opens sideways, and the exhaust duct outlet 49 opens downward. That is, the intake duct inlet 46 and the exhaust duct outlet 49 open upward. Therefore, the intrusion of rainwater or the like into the intake duct 45 or the exhaust duct 48 can be more reliably suppressed.

  In addition, in the present embodiment, the intake duct 45 and the exhaust duct 48 are provided by using the damper 3 having a power transmission buffer function as a rotating body and the clutch housing 11 that houses the dry clutch 4 and the motor generator 2. Therefore, the addition of new parts can be suppressed, and the air flow can be enhanced with a simple configuration.

  Particularly in the above embodiment, the intake duct 45 and the exhaust duct 48 are formed by using the intake duct member 43 and the exhaust duct member 44 which are separate parts from the housing cover 13 of the clutch housing 11, so The intake duct 45 and the exhaust duct 48 can be easily provided to the housing cover 13 without changing the shape of the housing cover 13 to be cast. In addition, since the intake duct member 43 and the exhaust duct member 44 are not required to have particularly high strength and rigidity, for example, by forming a mold using a synthetic resin material, it is easy to form a complicated pipe shape. It is possible to reduce the weight and cost.

  However, a tubular intake duct or exhaust duct may be formed integrally with the housing cover. In this case, although the shape of the housing cover is complicated, there is an advantage that the number of parts and the number of assembly steps are reduced.

  In the above embodiment, the present invention is applied to a power transmission device for a front wheel drive type hybrid vehicle. However, the present invention is not limited to this, and various vehicles having a dry friction clutch in the power transmission path, such as a rear wheel drive type hybrid vehicle. The present invention can also be applied to vehicles, electric vehicles that do not include an engine, vehicles that use only an engine as a drive source, and the like.

  Furthermore, in the above-described embodiment, the damper 3 is used as a rotating body that is axially separated from the dry friction clutch, but is not limited thereto, and is not limited thereto, such as a flywheel that rotates around the axis. Other rotating bodies may be used.

  Further, the dry friction clutch is not limited to the multi-plate type as in the above embodiment, but may be a single-plate type.

3 ... Damper (Rotating body)
4 ... 1st clutch (dry friction clutch)
4A ... Clutch input shaft 4B ... Clutch output shaft 11 ... Clutch housing 13 ... Housing cover 22 ... Clutch hub 23 ... Clutch drum 25 ... Hub side friction plate 26 ... Drum side friction plate 27 ... Friction material 28 ... Hydraulic piston (actuator)
30 ... Clutch chamber 41 ... Intake hole 42 ... Exhaust hole 43 ... Intake duct member 44 ... Exhaust duct member 45 ... Intake duct (air flow guide means)
46 ... Intake duct inlet 48 ... Exhaust duct (air flow guide means)
49 ... Exhaust duct outlets K1-K5 ... Air flow

Claims (5)

It is interposed between the clutch input shaft and the clutch output shaft, and has a dry friction clutch that switches between disconnection and connection of power transmission between both,
This dry friction clutch
A clutch hub that rotates with one of the clutch input shaft and the clutch output shaft;
A clutch drum provided on the outer peripheral side of the clutch hub so as to be relatively rotatable, and rotating together with the other of the clutch input shaft and the clutch output shaft;
A hub-side friction plate that extends radially outward from the clutch hub and engages the clutch hub movably in the axial direction;
Extending radially inward from the clutch drum, engaged with the clutch drum so as to be movable in the axial direction, and opposed to the hub side friction plate so as to be able to contact and separate in the axial direction. A drum side friction plate;
An actuator that switches between disconnection and connection of the power transmission by driving the hub-side friction plate and the drum- side friction plate in the axial direction to open or close each other;
And it is spaced apart in the axial direction from the dry friction clutch and is coaxially arranged, and a rotating body that rotates around the axis;
An airflow guide means for sending the air flowing in the vicinity of the outer peripheral portion of the rotating body by the rotation of the rotating body to the vicinity of the engaging portion between the clutch hub and the hub side friction plate;
A clutch housing that is supported on the vehicle body side so as to surround the dry friction clutch, and in which the clutch input shaft and the clutch output shaft are rotatably inserted,
The airflow guide means has a tubular intake duct,
The intake duct extends in the radial direction along the wall of the clutch housing while passing through the wall of the clutch housing disposed in the axial gap between the dry friction clutch and the rotating body in the axial direction. And
One end on the radially outer side of the intake duct opens in the vicinity of the outer peripheral portion of the rotating body, and the other end on the radially inner side of the intake duct is an engagement portion between the clutch hub and the hub side friction plate. A power transmission device for a vehicle characterized by opening in the vicinity of the vehicle. The power transmission device for a vehicle according to claim 1 , wherein the intake duct is disposed above the clutch input shaft and the clutch output shaft in the vertical direction. The one end of the intake duct, a power transmission apparatus for a vehicle according to claim 1 or 2, characterized in that it is open to face the rotation direction of the rotating body. The airflow guide means has a tubular exhaust duct,
The exhaust duct extends in the radial direction along the wall of the clutch housing while passing through the wall of the clutch housing disposed in the axial gap between the dry friction clutch and the rotating body in the axial direction. One end of the exhaust duct on the outer side in the radial direction opens in the vicinity of the engagement portion between the clutch drum and the drum side friction plate, and the other end on the inner side in the radial direction of the exhaust duct The power transmission device for a vehicle according to any one of claims 1 to 3 , wherein the power transmission device is opened in the vicinity of a central shaft portion of the body. The power transmission device for a vehicle according to claim 4 , wherein an opening direction of the other end of the exhaust duct is set in the same direction as a rotation direction of the rotating body.

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