JP2012141000A - Damper with limiter for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper with a limiter constituting a power transmission mechanism of a hybrid vehicle, the damper with the limiter capable of eliminating variations of limiter torque and reducing the outer diameter.SOLUTION: The damper with the limiter for the hybrid vehicle includes: a limiter part 1 of a multi-plate structure in which lubricating oil is filled into an outer case 3 comprising a rear cover 22 and a front cover 21 connected by a drive plate 23 and which includes a plate spring 11 at an outer circumferential inner side of the outer case 3; and a damper part 2 including a plurality of damper springs 4 at an inner diameter side of the limiter part 1. A hub 19 having a shaft hole 24 into which an output shaft is fitted is mounted at the center of the damper part 2.

Description

  The present invention relates to a wet type damper with a limiter that can be attached to a hybrid vehicle and ensures a stable torque capacity.

  The hybrid vehicle is provided with a damper with a limiter so as to reduce the impact torque and to slip when a predetermined torque is exceeded. Therefore, the structure is such that the damper and other units (transmission unit) are not damaged due to excessive torque. Therefore, in the case of a general hybrid vehicle, the motor and the engine are used properly, and the engine operates in a region where the engine efficiency is good. However, these torques are transmitted to the output shaft to drive the axle. A damper with a limiter is interposed between the crankshaft extending from the engine and the output shaft.

  The damper with limiter includes a plurality of damper springs, and a limiter is provided on the outer peripheral portion. A flywheel is interposed between the damper with the limiter and the crankshaft, the outer periphery of the damper with the limiter is screwed to the flywheel, and the inner periphery of the flywheel is screwed to the crankshaft. In hybrid vehicles, excessive torque may be generated due to fluctuations in the driving load or engine load when the engine is driven or when the motor is started. Therefore, when excessive torque is generated, the limiter works to cause slippage. It consists of a structure to do.

  However, the conventional limiter torque has a large variation, and the limiter often does not work even when a predetermined torque is reached. In other words, this is due to the large variation in the friction coefficient (μ) of the friction material provided in the limiter. In particular, the friction coefficient (μ) increases due to the occurrence of rust on the engagement surface of the conventional dry friction material, and accordingly the limiter torque becomes extremely large. As a result, the damper and other units (transmission units) are damaged by excessive torque.

  Therefore, conventionally, the power transmission mechanism and the speed change mechanism must be designed in consideration of variations in limiter torque, and the outer diameter of the output shaft, the dimensions of the damper spring, and the like are necessarily increased. However, the lower limiter torque needs to be greater than the engine torque and the engine starting torque so as not to slip.

  “Damper with limiter for hybrid vehicle” according to Japanese Patent Application Laid-Open No. 2008-273235 is an invention applied by the applicant on April 25, 2007, and is a damper with limiter that constitutes a power transmission mechanism of a hybrid vehicle. Thus, the limiter torque variation is suppressed. Therefore, a damper having a plurality of damper springs is provided in an outer case constituted by a front cover and a rear cover connected to the drive plate. An outer peripheral plate provided with friction material is attached to the outer periphery of the damper disk and sandwiched by a limiter plate pressed by a disc spring, and a hub having a shaft hole into which the output shaft is fitted is attached to the center of the damper. The outer case is filled with lubricating oil.

In addition to this, the applicant has filed several patent applications relating to “damper with limiter”.
“Attachment structure of a damper with a limiter for a hybrid vehicle” according to Japanese Patent Application Laid-Open No. 2008-273256
“Damper with Limiter for Hybrid Vehicle” according to Japanese Patent Application Laid-Open No. 2008-274968
“Damper with Limiter for Hybrid Vehicle” according to Japanese Patent Application Laid-Open No. 2008-274969
“Attachment structure of a damper with a limiter for a hybrid vehicle” according to Japanese Patent Application Laid-Open No. 2009-062022
“Damper with limiter” according to JP 2009-243535 A
“Damper with limiter” according to JP 2010-106948 A

  By the way, these limiter-equipped dampers are wet, and the outer case is filled with lubricating oil, and a wet friction material is adhered to the outer peripheral plate in order to ensure torque capacity, and spring force is applied to the outer peripheral plate. A disc spring is used for biasing. That is, when the disc spring is compressed, a spring force is generated, and the outer peripheral plate with the friction material adhered can be sandwiched between the limiter plate and the outer case. Here, the disc spring forms a ring body having a constant width, is compressed with respect to the axial load, changes the inclination angle, and approaches a flat surface.

  At this time, the ring body of the disc spring is stretched by being pulled on the outer peripheral side and compressed on the inner peripheral side. Although all the deformations are in the elastic range, the spring force of the disc spring based on the deformation amount is large, and the transmitted torque capacity greatly affects the assembly error of the damper with the limiter. In particular, when the disc spring is assembled by being greatly compressed and deformed, the generated spring force changes greatly with a slight error.

  Further, the relationship between the compressive strain and the load (stress) also changes depending on the material change of the spring material used as the material of the disc spring. In particular, the change in load (stress) increases as the amount of compression (strain) increases. For this reason, a stable transmission torque capacity is ensured by relatively reducing the load acting on the disc spring. For this purpose, it is preferable to employ a multi-plate limiter whose friction surface is enlarged with a small load.

  As a damper with a limiter provided with a multi-plate limiter, a “torque fluctuation absorber” according to Japanese Patent Application Laid-Open No. 2008-304008 is known. This torque fluctuation absorber is arranged to improve the high torsional performance and damping performance of the torque fluctuation absorber having a torque limit function by arranging the damper portion on the outer periphery. Therefore, the power transmission path from the flywheel to the inner peripheral hub member has a damper portion, a limiter portion, and a hysteresis portion.

  Therefore, the limiter portion is arranged on the inner diameter side from the damper portion, and in order to transmit a predetermined torque for that purpose, the spring force of the disc spring constituting the limiter portion must be increased. That is, when the limiter portion is arranged on the inner diameter side, in order to ensure the same torque capacity, it is necessary to withstand a large load by strengthening the spring force of the disc spring. The above-mentioned problem occurs in the same manner as a disc spring used in a “damper with limiter”.

“Damper with Limiter for Hybrid Vehicle” according to Japanese Patent Application Laid-Open No. 2008-273235 “Attachment structure of a damper with a limiter for a hybrid vehicle” according to Japanese Patent Application Laid-Open No. 2008-273256, “Damper with Limiter for Hybrid Vehicle” according to Japanese Patent Application Laid-Open No. 2008-274968 "Damper with limiter for hybrid vehicle" according to JP 2008-274969 A, "Attachment structure of a damper with a limiter for a hybrid vehicle" according to JP 2009-062022 A, “Damper with limiter” according to JP 2009-243535 A “Damper with limiter” according to JP 2010-106948 A “Torque Fluctuation Absorbing Device” according to JP 2008-304008 A

  Thus, the conventional damper with limiter mounted on the hybrid vehicle has the above-mentioned problems. The problem to be solved by the present invention is this problem, with a limiter for a hybrid vehicle configured to ensure a sufficient and stable torque capacity, and to reduce the weight by reducing the outer diameter. Provide a damper.

  The damper with a limiter of the present invention has a damper and a limiter interposed between them when transmitting the torque of the crankshaft to the output shaft, and this basic structure is the same as the conventional one. A limiter portion is provided inside the outer periphery of the outer case. The limiter portion has a multi-plate structure and includes a plurality of lining plates and plates that can be frictionally engaged with each other. A disc spring is interposed between the outer case and the plate to urge the spring force so that the lining plate and the plate are pressed against each other.

  Spline teeth are provided on the outer periphery of the plate of the limiter part, the spline teeth mesh with the spline teeth provided on the inner peripheral surface of the outer case, and the spline teeth are provided on the inner periphery of the lining plate. Meshes with spline teeth provided on the outer periphery of the input member of the damper portion. Here, in order to position the lining plate in the axial direction, a small protrusion is provided on the spline root provided on the outer periphery of the input member.

  The damper portion is provided with a plurality of damper springs on the inner diameter side of the limiter portion, and the damper spring expands and contracts, whereby the input member and the output member attached to the hub rotate relative to each other. Further, in order to arrange the damper springs in series, the intermediate member can be rotatably supported and a separator can be interposed between the damper springs. The damper with a limiter according to the present invention has a wet structure. For this purpose, the damper is provided with an outer case and accommodated therein, and the outer case is filled with lubricating oil. The outer case is welded to a front cover and a rear cover that also serve as a flywheel, the hub is attached to the center of the damper portion, and the output shaft is fitted in a shaft hole provided in the hub.

  On the other hand, in the present invention, when the friction member is interposed between the input member or the intermediate member for connecting the damper spring in series and the output member, and the relative torsional rotation angle between the input member and the output member becomes a certain level or more. To generate sliding friction. However, in the present invention, the specific structure of the output member that is input from the input member and transmitted to the hub is not limited.

  The damper with a limiter according to the present invention has a wet structure in which the outer case is housed and the outer case is filled with lubricating oil. Therefore, the friction material of the limiter portion always has a constant coefficient of friction. That is, there is no rust on the friction material engaging surface, and variation in limiter torque can be suppressed. The limiter unit has a disc spring interposed between the outer case and a multi-plate structure having a plurality of lining plates and plates, so that the friction surface is increased and the disc spring is greatly compressed to generate a spring force. Even if it does not increase, the generated frictional force becomes large, and the necessary transmission torque capacity is secured.

  That is, since a stable spring force is generated by suppressing the amount of compression deformation of the disc spring, the required transmission torque capacity is ensured without variation. Moreover, the damper with the limiter according to the present invention has the limiter portion arranged on the outer periphery inside the outer case, so that the load acting on the limiter portion with respect to the same transmission torque is reduced, which is a great requirement for stabilizing the torque capacity. Thus, since the limiter part is arranged inside the outer periphery of the outer case and has a multi-plate structure, the outer diameter of the outer case that accommodates the limiter part can be made small and compact, and can be easily mounted on a hybrid vehicle. Moreover, the energy consumption accompanying rotation decreases.

The Example which shows the damper with a limiter concerning this invention. Detailed view of the limiter unit. Part detail drawing of a damper part. The top view containing the partial cross section of the damper with a limiter. Another embodiment showing a damper with a limiter according to the present invention.

  FIG. 1 shows an embodiment of a damper with a limiter according to the present invention, and shows a sectional view. In the figure, 1 is a limiter section, 2 is a damper section, and 3 is an outer case. The damper section 2 has the same basic structure as that used in the torque converter, and includes a plurality of damper springs 4, 4, and each damper spring 4, 4. And is accommodated in a spring accommodating space 7 formed in the A plate 5 and the B plate 6.

  Then, the A plate 5 and the B plate 6 are combined with rivets, and a central disk 8 as an input member of the damper portion 2 is sandwiched between them, and the damper springs 4, 4. The central disk 8 and the A plate 5 and B plate 6 perform relative rotation. The central disk 8 is sandwiched between the A plate 5 and the B plate 6, and a slight gap is provided on the outer peripheral side of both the A and B plates 5, 6 so that the central disk can be in sliding contact only on the inner peripheral side. It is said. Accordingly, it is possible to suppress variations in hysteresis due to the relative rotation generated between the central disk 8 and the A / B plates 5 and 6 and to suppress vibration.

  The intermediate member 9 is disposed on the inner diameter side of the disk-shaped central disk 8 and the separator 18 of the intermediate member 9 is interposed between the two damper springs 4 and 4 arranged in pairs. They are connected in series. Further, the outer periphery of the central disk 8 is bent into an L shape to form a connecting portion 10, and the connecting portion 10 is connected to the limiter portion 1.

  By the way, the limiter unit 1 is configured to transmit torque input from the engine to the outer case 3 to the damper unit 2, but to be able to slip when a large impact torque exceeding a certain level is generated. As shown in detail in FIG. 2, the limiter unit 1 includes a disc spring 11, plates 12a and 12b, and lining plates 13a and 13b, and spline teeth provided on the outer circumferences of the ring-shaped plates 12a and 12b are formed on the outer case. 3 and the spline teeth formed on the inner periphery of the ring-shaped lining plates 13a and 13b mesh with the spline teeth 15 formed on the outer periphery of the connecting portion 10 of the central disk 8. ing.

  Friction material is adhered to both surfaces of the lining plates 13a, 13b, and the plates 12a, 12b and the lining plates 13a, 13b are pressed against each other by the action of the spring force of the disc spring 11. Accordingly, the rotational torque of the outer case 3 is transmitted to the central disk 8 via the limiter unit 1. However, when the torque exceeds a certain level, the plates 12a and 12b and the lining plates 13a and 13b can slip. Here, a protrusion 16 is provided on the bottom of the spline tooth 15 of the connecting portion 10, and the protrusion 16 is sandwiched between the lining plates 13 a and 13 b, thereby positioning the damper portion 2 in the axial direction.

  The disc spring 11 is a ring body having a constant width and is slightly inclined when no load is applied. However, the plate spring 11 is flattened when the load is applied to increase the degree of compression. 11 is pressed by the spring force. In the present invention, since the limiter unit 1 has a multi-plate structure, the frictional force generated by the same amount of spring force increases, and as a result, the torque capacity that can be transmitted is increased. Therefore, if there is no change in the torque capacity, the spring force acting on the compression of the disc spring 11 can be small. That is, a required friction capacity can be secured by generating a predetermined frictional force with a small compression.

  As shown in FIG. 3, the center disk 8 has a ring shape, and spring retainers 17, 17,... Protrude from the inner periphery thereof, and two damper springs 4 are disposed between the adjacent spring retainers 17, 17. , 4 are arranged in series. Of course, the two damper springs 4 and 4 are accommodated in a spring accommodating space 7 formed by the A plate 5 and the B plate 6. A separator 18 is interposed between the damper springs 4 and 4 in series. The separator 18 protrudes from the outer periphery of the ring-shaped intermediate member 9 that is pivotally supported by the flange 20 of the hub 19. Therefore, when the damper springs 4 and 4 are compressed and deformed, the central disk 8 rotates relatively fast with respect to the A plate 5 and the B plate 6 attached to the hub 19. The damper springs 4 and 4 in series can be uniformly compressed and deformed by rotating.

  FIG. 4 shows a front view including a partial cross section of the damper with limiter. The outer case 3 is a combination of a front cover 21 and a rear cover 22, the outer periphery of which is welded, and a drive plate 23 attached to the crankshaft of the engine is connected. A hub 19 having a shaft hole 24 is provided at the center of the outer case 3, and the hub 19 is fixed to the inner peripheral portion of the B plate 6. The outer case 3 is constructed by welding a front cover 21 and a rear cover 22 that also function as a flywheel. A sleeve 25 is formed at the center of the rear cover 22, and the sleeve 25 is concentric with the hub 19.

  As described above, the inner peripheral portion of the B plate 6 is fixed to the flange 20 of the hub 19 by the rivets 26, 26,..., The intermediate member 9 is rotatably supported on the outer periphery of the flange 20, and the flange A friction member 27 and a washer 28 are attached to the outer periphery. Here, the outer periphery of the friction member 27 has locking pieces 29, 29... Bent in an L shape, and these locking pieces 29, 29. It can be locked in the stop grooves 30, 30... (See FIG. 3). Further, the washer 28 is provided with locking pieces 31, 31... Bent in an L shape on the inner periphery thereof, and these locking pieces 31, 31. It is locked in the stop groove. A disc spring 32 is interposed between the inner peripheral portion of the B plate 6 and the washer 28.

  Accordingly, the spring force of the disc spring 32 acts on the washer 28 and the friction member 27, and a frictional force that suppresses relative rotation between the friction member 27 and the washer 28 is generated. As described above, the locking pieces 31, 31... Of the washer 28 are locked in the locking grooves of the B plate 6, and the locking pieces 29, 29. It is possible to generate a frictional force that suppresses relative rotation between the B plate 6 and the intermediate member 9 by being locked to 30, 30.

  The intermediate member 9 rotates with the expansion and contraction of the damper springs 4, 4..., But the rotation is suppressed by the friction member 27. Here, the locking groove 30 provided in the intermediate member 9 is longer than the locking piece 29, and the predetermined angle rotates without being restricted by the locking piece 29. Abut. That is, the locking piece 29 can be engaged with the locking groove 30 with a play of a predetermined rotation angle.

  As the damper springs 4, 4... Expand and contract, the intermediate member 9 rotates by a predetermined angle or more, and the locking pieces 29, 29. If the front end of the friction member 27 abuts, the friction member 27 rotates together with the intermediate member 9. However, the friction member 27 is biased by the spring force of the disc spring 32, and is accompanied by a predetermined sliding frictional force with the washer 28 when rotating. Therefore, a large impact torque is relieved and absorbed by the sliding friction of the friction member 27 together with the expansion and contraction of the damper springs 4, 4. Therefore, it is possible to use a damper spring 4 having a relatively low spring constant.

  On the other hand, as shown in FIG. 4, set blocks 33, 33... Are welded to the outer periphery of the front cover 17, and the drive plate 23 is screwed to these set blocks 33, 33. The drive plate 23 is connected to a crankshaft (not shown). A center portion 34 is provided at the center of the front cover 21 to fit in the center hole of the crankshaft. Accordingly, the torque of the crankshaft is transmitted to the outer case 3 through the drive plate 23, and the limiter unit 1 and the damper unit 2 can be rotated.

  By the way, normal impact torque and torque fluctuation are absorbed by the elastic deformation of the damper springs 4, 4,..., And when the elastic deformation amount of the damper springs 4, 4,. The rotation of the intermediate member 9 that rotates with the expansion / contraction deformation is suppressed by the friction member 27. That is, a part of the impact torque is absorbed by the frictional rotation of the friction member 27. When a larger impact torque is generated, it is relieved by auxiliary damper springs 35, 35,.

  When a larger torque is input, the damper springs 4, 4... And the auxiliary damper springs 35, 35... Of the damper part 2 expand and contract, but the limiter part 1 operates and idles. In the present invention, the outer case 3 is filled with lubricating oil, and the limit torque at which the limiter unit 1 idles is substantially constant. That is, the friction material engaging surfaces of the plates 13a and 13b are not rusted by the lubricating oil, and a constant friction coefficient is always maintained. Further, the damper with limiter according to the present invention is filled with lubricating oil in the outer case 3, so that the central disk 8, the A plate 5, the B plate 6, which constitutes the damper portion 2 provided inside the outer case 3, The intermediate member 9, the damper springs 4, 4... And the friction member 27 can be lubricated.

In the embodiment of the damper with limiter shown in FIG. 1, the central disk 8 as the input member of the damper portion 2 is sandwiched between the A plate 5 and the B plate 6 as the output member, and a plurality of damper springs 4, 4,. It is the structure connected via. However, in the present invention, the specific structures of the input member and the output member are not limited to the case shown in FIG. Further, a protrusion 16 is provided on the bottom of the spline tooth 15 of the connecting portion 10, and the protrusion 16 is sandwiched between both lining plates 13 a and 13 b, thereby positioning the damper portion 2 in the axial direction.
However, the means for positioning the damper portion 2 is not limited to the case where the protrusion 16 is provided on the spline tooth bottom of the connecting portion 10, and a washer can be fitted in a groove formed on the outer periphery of the connecting portion.

  FIG. 5 shows another embodiment of the damper with limiter according to the present invention. In the figure, reference numeral 1 denotes a limiter portion, 2 denotes a damper portion, and 3 denotes an outer case, and the structure is common to the damper with limiter shown in FIG. However, in the damper with limiter, the structure of the drive plate 38 for connecting with the crankshaft is different. That is, the drive plate 38 is configured by welding the flywheel 36 to the outer periphery thereof.

  Thus, by attaching the flywheel 36 to the outer periphery of the drive plate and connecting it to the front cover 21, the overall strength of the damper with the limiter is improved and the inertia is increased, but the drive plate formed of a plate material on the inner diameter side. Since it is 38, a significant increase in weight can be suppressed. Thus, the effect of suppressing vehicle vibration can be obtained by attaching the flywheel 36 to the outer periphery of the drive plate and increasing the inertia. Here, the welding is not limited to the means for attaching the flywheel 36 to the outer periphery of the drive plate, but may be riveted. In the case of welding, it is preferable to weld the rear side as shown in the figure in consideration of deformation of the flange 37 formed on the outer periphery of the drive plate 38.

DESCRIPTION OF SYMBOLS 1 Limiter part 2 Damper part 3 Outer case 4 Damper spring 5 A plate 6 B plate 7 Spring accommodation space 8 Central disk 9 Intermediate member
10 Connecting part
11 Belleville spring
12 plates
13 Lining plate
14 spline teeth
15 spline teeth
16 protrusion
17 Spring presser
18 Separator
19 Hub
20 Flange
21 Front cover
22 Rear cover
23 Drive plate
24 Shaft hole
25 sleeves
26 Rivet
27 Friction material
28 Washers
29 Locking piece
30 Locking groove
31 Locking piece
32 Belleville spring
33 set blocks
34 Center
35 Auxiliary damper spring
36 flywheel
37 Flange
38 Drive plate

Claims (7)

In a damper with a wet limiter that constitutes the power transmission mechanism of a hybrid vehicle, the outer case constituted by the front cover and the rear cover connected to the drive plate is filled with lubricating oil, and a plurality of lining plates are provided on the outer periphery of the outer case. And a multi-plate limiter part having a plate and a disc spring, a damper part having a plurality of damper springs provided on the inner diameter side of the limiter part, and a spline tooth provided on the outer periphery of the plate of the limiter part Is engaged with the spline teeth formed on the inner peripheral surface of the outer case, and the spline teeth provided on the inner periphery of the lining plate are engaged with the spline teeth formed on the connection portion of the outer periphery of the input member of the damper portion. A damper with a limiter, characterized in that a hub having a shaft hole into which the output shaft fits is attached at the center. The damper with a limit according to claim 1, wherein a small protrusion is provided on the spline tooth bottom of the outer periphery of the input member and is positioned between the lining plates. 3. The damper according to claim 1 or 2, wherein the damper portion includes a central disk serving as an input member sandwiched between an A plate and a B plate which are output members and the damper spring is accommodated in a spring accommodating space. damper. A friction member is interposed between the B plate serving as the output member and the intermediate disk or damper spring serving as the input member in series, and a spring force is applied to the friction member to deform the damper spring. 4. A damper with a limiter according to claim 3, wherein when the input member and the output member rotate relative to each other, sliding friction of a constant angle is generated. The center disk is sandwiched between the A plate and the B plate, and a slight gap is provided on the outer peripheral side of both the A and B plates so that the central disk can be in sliding contact only on the inner peripheral side. Item 5. A damper with a limiter according to item 4. A spring retainer is provided on the inner circumference of the ring-shaped central disc, and two damper springs are arranged in series between the adjacent spring retainers. Between the two damper springs, the flange is supported by the flange of the hub. A separator projecting on the outer periphery of the intermediate member is interposed, and a locking piece of the friction member is engaged with a locking groove of the intermediate member with a play of a predetermined rotation angle, and between the B plate side which is an output member 6. The damper with a limiter according to claim 3, wherein sliding friction is generated when the relative torsional rotation angle exceeds a certain value. The means for positioning the damper portion in the axial direction, wherein a washer is fitted in a groove provided on the outer periphery of the connecting portion in place of the protrusion. 7. The claim 3, claim 4, claim 5, or claim 6. Damper with limiter.

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