JP2015004390A - Vehicle power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a vehicle power transmission device exert effective vibration control performance in a wide input rotation number range by combining a centrifugal pendulum type damper and a toroidal gear change mechanism.SOLUTION: A vehicle power transmission device comprises a centrifugal pendulum type damper 15 and a two-stage type toroidal gear change mechanism 18. In the centrifugal pendulum type damper 15, at high-speed cruising or the like in which the number of revolutions of an engine E is low, vibration control performance is lowered, however, at this time, the toroidal gear change mechanism 18 is increased in a speed ratio and also increased in an inertia mass, a vibration transmission rate between the engine E and drive wheels W is decreased, and thereby a vibration/noise property of a vehicle can be enhanced by compensating the lowering of the vibration control performance of the centrifugal pendulum type damper. In particular, since the toroidal gear change mechanism 18 is constituted to a two-stage type having an input disc 27, an intermediate disc 29 and an output disc 28, an inertia mass can be increased by expanding the speed ratio compared with a one-stage type, the vibration transmission rate can be effectively lowered, and the vibration control performance can be enhanced.

Description

  The present invention relates to a vehicle power transmission device that transmits a driving force of a driving source to driving wheels via a centrifugal pendulum damper and a toroidal transmission mechanism.

  A centrifugal for a vehicle that supports a plurality of inertial mass bodies on a flywheel that rotates together with an output shaft of an engine, and causes the inertial mass bodies to vibrate in a circumferential direction in accordance with rotational fluctuations of the output shaft to exert a damping performance. A pendulum type damper is known from Japanese Patent Application Laid-Open No. 2004-228561.

Japanese Patent No. 4797176

  FIG. 6 shows the relationship between the output torque fluctuation and the input rotation speed of the centrifugal pendulum damper. In the region where the input rotation speed for the centrifugal pendulum damper is large, the centrifugal force acting on the inertial mass body is large, so that the damping performance is fully exerted and the output torque fluctuation is reduced, but the input rotation speed for the centrifugal pendulum damper is small. In a region where is small, the centrifugal force acting on the inertial mass body is small, so that the vibration damping performance is not sufficiently exhibited and the output torque fluctuation increases. That is, the centrifugal pendulum damper can exhibit effective vibration damping performance in a high rotation region, but has a problem that the performance cannot be fully utilized in a low rotation region.

  The present invention has been made in view of the above circumstances, and an object thereof is to exhibit effective damping performance in a wide input rotation speed range by combining a centrifugal pendulum damper and a toroidal transmission mechanism.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a vehicle power transmission device for transmitting a driving force of a driving source to driving wheels via a centrifugal pendulum damper and a toroidal transmission mechanism. The toroidal transmission mechanism includes a rotating shaft to which a driving force from the centrifugal pendulum damper is input, an input disk that rotates together with the rotating shaft, an output disk that is rotatably supported by the rotating shaft, An intermediate disk that is rotatably supported by the rotary shaft between the input disk and the output disk, a first power roller sandwiched between the input disk and the intermediate disk, and between the intermediate disk and the output disk A vehicular power transmission device including a second power roller that is sandwiched is proposed.

  The input shaft 12 of the embodiment corresponds to the rotating shaft of the present invention, the secondary damper 15 of the embodiment corresponds to the centrifugal pendulum damper of the present invention, and the engine E of the embodiment is driven by the present invention. Corresponds to the source.

  According to the configuration of the first aspect, the vehicle power transmission device transmits the driving force of the driving source to the driving wheels via the centrifugal pendulum damper and the toroidal transmission mechanism. The toroidal transmission mechanism includes a rotating shaft to which a driving force from a centrifugal pendulum damper is input, an input disk that rotates together with the rotating shaft, an output disk that is rotatably supported by the rotating shaft, and an input disk and an output disk. The intermediate disk supported rotatably on the rotation shaft, a first power roller sandwiched between the input disk and the intermediate disk, and a second power roller sandwiched between the intermediate disk and the output disk. The rotation of the input disk is shifted by the first power roller and transmitted to the intermediate disk, and the rotation of the intermediate disk 29 is shifted by the second power roller and transmitted to the output disk.

  Centrifugal pendulum dampers have effective damping performance when the rotational speed of the drive source is high and the centrifugal force acting on the inertial mass body is large, that is, when the speed ratio of the toroidal transmission mechanism is small (when the gear ratio is large). Demonstrate. On the other hand, when the speed ratio is large (when the speed ratio is small), the toroidal speed change mechanism increases the equivalent inertia and decreases the resonance frequency of the torsional vibration system between the drive source and the drive wheels. The transmission rate is reduced and the damping performance is demonstrated. Since the toroidal transmission mechanism shifts between the input disk and the intermediate disk and shifts between the intermediate disk and the output disk, the speed ratio can be increased by the two-stage shift, and therefore the resonance frequency The amount of decrease can be increased to exhibit effective damping performance.

  Therefore, the centrifugal pendulum damper exhibits effective damping performance in the region where the rotational speed of the drive source is high (region where the speed ratio is small), and the toroidal transmission mechanism in the region where the rotational speed of the drive source is low (region where the speed ratio is large). By exhibiting effective vibration damping performance, it is possible to improve the vibration damping performance in a wide range of the rotational speed of the drive source.

The skeleton figure of the power transmission device for vehicles. Explanatory drawing of the equivalent inertia of a toroidal transmission mechanism. The graph which shows the relationship between the vibration transmissibility between an engine and a driving wheel, and a vibration frequency. The table | surface which shows the comparison of the damping performance of a secondary damper and a toroidal transmission mechanism. Explanatory drawing of the area | region which supplements the damping performance of a centrifugal pendulum type damper with the damping performance of a toroidal transmission mechanism. The graph which shows the change of the damping performance of a centrifugal pendulum type damper according to input rotation speed.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a continuously variable transmission T for an automobile that continuously changes the driving force of the engine E and transmits it to the left and right drive wheels W, W is disposed coaxially with the crankshaft 11 of the engine E. The input shaft 12 and the output shaft 13 arranged in parallel with the input shaft 12 are provided. Between the crankshaft 11 and the input shaft 12, a primary damper 14, a secondary damper 15, a forward / reverse switching mechanism 16, and a driving force integration mechanism 17 are arranged in series from the engine E side. A toroidal speed change mechanism 18 is disposed on 12.

  The primary damper 14 and the secondary damper 15 are for absorbing fluctuations in the output torque of the engine E. The primary damper 14 is a general damper that combines a flywheel 14a and a spring 14b, and the secondary damper 15 is a centrifugal damper. This is a pendulum damper. The centrifugal pendulum damper supports a plurality of pendulums 15b that can be swung in the circumferential direction on the outer periphery of a rotating hub 15a. The pendulum 15b vibrates due to centrifugal acceleration according to a change in output torque of the engine E. To demonstrate vibration control performance.

  The forward / reverse switching mechanism 16 includes a forward clutch 19, a reverse brake 20, and a planetary gear mechanism 21, and the planetary gear mechanism 21 is supported by a sun gear 22, a ring gear 23, a carrier 24, and a carrier 24 and is a sun gear. 22 and a plurality of pinions 25 that mesh with the ring gear 23. The sun gear 22 is connected to the output side of the secondary damper 15 and can be coupled to the input shaft 12 via the forward clutch 19. The ring gear 23 is connected to the input shaft 12. The carrier 24 can be coupled to the casing 26 via the reverse brake 20.

  The toroidal transmission mechanism 18 is configured in a two-stage manner by connecting two single cavity type devices in series. The input disk 27 supported on the input shaft 12 so as not to rotate relative to the input shaft 12 A pair of abutting contacts with the input disk 27 and the intermediate disk 29, an output disk 28 that is rotatably supported, an intermediate disk 29 that is rotatably supported by the input shaft 12 at a position between the input disk 27 and the output disk 28. First power rollers 30 and 30, and a pair of second power rollers 31 and 31 in contact with the intermediate disk 29 and the output disk 28.

  The first power rollers 30, 30 can tilt around the first trunnion shafts 32, 32, and when the first power rollers 30, 30 tilt and the contact points between the input disk 27 and the intermediate disk 29 change, The transmission ratio between the input disk 27 and the output disk 28 changes. Similarly, the second power rollers 31, 31 can tilt around the second trunnion shafts 33, 33, and the second power rollers 31, 31 tilt to contact the intermediate disk 29 and the output disk 28. When it changes, the gear ratio between the intermediate disk 29 and the output disk 28 changes.

  The rotation of the input disk 27 is transmitted to the intermediate disk 29 via the first power rollers 30 and 30, and the rotation of the intermediate disk 29 is transmitted to the output disk 28 via the second power rollers 31 and 31. If the transmission ratio from 27 to the intermediate disk 29 is i1, and the transmission ratio from the intermediate disk 29 to the output disk 28 is i2, the transmission ratio i from the input disk 27 to the output disk 28 is i = i1 × i2. . Therefore, the range of the transmission ratio i from the input disk 27 to the output disk 28 can be greatly expanded by increasing or decreasing the transmission ratio i1 and the transmission ratio i2 in the same direction.

  The driving force integration mechanism 17 is composed of a planetary gear mechanism, and is supported on the outer periphery of the input shaft 12 so as to be relatively rotatable, a sun gear 34 fixed to the input shaft 12, a ring gear 35 fixed to the back surface of the output disk 28, and the like. Carrier 36 and a plurality of double pinions 37 supported by the carrier 36. Each double pinion 37 includes a first pinion 38 and a second pinion 39. The first pinion 38 meshes with the sun gear 34, and the second pinion 39 meshes with the ring gear 35.

  The drive gear 40 fixed to the carrier 36 which is an output element of the driving force integration mechanism 17 meshes with the driven gear 41 fixed to the output shaft 13, and the final drive gear 42 fixed to the output shaft 13 is the case of the differential gear D. Meshes with a final driven gear 43 fixed to the wheel. Then, a pair of axles 44, 44 extending from the differential gear D to the left and right are connected to the drive wheels W, W.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  When the forward clutch 19 of the forward / reverse switching mechanism 16 is engaged and the reverse brake 20 is disengaged, the secondary damper 15 is coupled to the input shaft 12. Therefore, the driving force of the engine E is changed from the crankshaft 11 to the primary. It is transmitted to the ring gear 35 of the driving force integrating mechanism 17 through the path of the damper 14, the secondary damper 15, the forward / reverse switching mechanism 16, the input shaft 12, and the toroidal transmission mechanism 18, and from there, the second pinion 39 of the double pinion 37 ... Is transmitted to the carrier 36 via.

  On the other hand, the driving force of the input shaft 12 is directly transmitted from the sun gear 34 of the driving force integrating mechanism 17 to the carrier 36 via the first pinions 38 of the double pinions 37... And transmitted from the toroidal transmission mechanism 18 at the carrier 36. After merging with the driving force, it is transmitted to the drive wheels W, W through the path of drive gear 40 → driven gear 41 → final drive gear 42 → final driven gear 43 → differential gear D → axles 44, 44.

  In this way, the driving force transmitted directly from the input shaft 12 and the driving force that is shifted and transmitted from the input shaft 12 via the toroidal transmission mechanism 18 are merged by the driving force integration mechanism 17, so that the toroidal transmission is performed. Not only can the transmission ratio of the entire continuously variable transmission T be changed in accordance with the change of the transmission ratio of the mechanism 18, but the power transmission ratio of the entire continuously variable transmission T can be increased by compensating for a decrease in the transmission ratio of the toroidal transmission mechanism 18. be able to.

  Now, part of the vibration of the continuously variable transmission T resulting from the fluctuation of the output torque of the crankshaft 11 of the engine E is damped by the primary damper 14 and the secondary damper 15. As already described with reference to FIG. 6, the higher the input rotational speed of the secondary damper 15 (that is, the engine rotational speed), the greater the centrifugal force acting on the inertial mass body 15b, so that the secondary damper 15 is controlled. Vibration performance is increased. In other words, when the engine speed is low, the secondary damper 15 cannot exhibit sufficient vibration damping performance. In the present embodiment, the decrease in the vibration damping performance of the secondary damper 15 when the engine speed is low is compensated by the vibration damping performance of the toroidal transmission mechanism 18.

FIG. 2A shows a physical model that simplifies the toroidal transmission mechanism 18 of the present embodiment. The inertia of the input disk 27 is Ii, the inertia of the intermediate disk 29 is Im, the inertia of the output disk 28 is Io, the speed ratio between the input disk 27 and the intermediate disk 29 is α, and the speed between the intermediate disk 29 and the output disk 28 is If the ratio is β, the equivalent inertia Icvt of the entire toroidal transmission mechanism 18 is
Icvt = Ii + α ² Im + β ² Io
Given in.

  The speed ratio is defined by (output rotational speed / input rotational speed), and corresponds to the reciprocal of the reduction ratio defined by (input rotational speed / output rotational speed).

Incidentally, as shown in FIG. 2B, the equivalent inertia Icvt of the entire one-stage toroidal transmission mechanism 04 including the input disk 01, the output disk 02, and the power roller 03 is Ii as the inertia of the input disk 01. If the inertia of the disk 02 is Io and the speed ratio between the input disk 27 and the output disk 28 is γ,
Icvt = Ii + γ ² Io
Given in.

  Since the maximum values of the transmission ratios α, β, and γ are all about 5.0 to 7.5, the equivalent inertia Icvt of the two-stage toroidal transmission mechanism 18 of the present embodiment is one-stage toroidal. This is significantly larger than the equivalent inertia Icvt of the speed change mechanism 04.

  FIG. 3 is a graph showing the relationship between the vibration transmissibility from the engine E to the axles 44 and 44 and the vibration frequency. The solid line indicates a case where the equivalent inertia Icvt is small, and the broken line indicates a case where the equivalent inertia Icvt is large. As is apparent from this graph, when the equivalent inertia Icvt of the toroidal transmission mechanism 18 increases, the resonance frequency shifts to the lower side. In the practical frequency region, which is a frequency region higher than the resonance frequency, the vibration transmissibility gradually decreases as the frequency increases. Therefore, the vibration transmissibility decreases as the resonance frequency shifts to the lower side.

In summary, as shown in the table of FIG. 4, during high-speed cruise of a vehicle in which the engine speed decreases and the speed ratio of the toroidal transmission mechanism 18 increases, the secondary damper 15 (centrifugal pendulum 15 decreases due to the decrease in engine speed. The vibration damping performance of the type damper) deteriorates, but the equivalent inertia increases due to the increase in the speed ratio of the toroidal transmission mechanism 18, so that the vibration transmission rate is lowered and the vibration damping performance is improved.
On the other hand, when the vehicle starts to accelerate or travels at medium speed when the engine speed increases and the speed ratio of the toroidal transmission mechanism 18 decreases, the equivalent inertia decreases due to the decrease of the speed ratio of the toroidal transmission mechanism 18 to transmit vibration. Although the rate is increased and the vibration damping performance is deteriorated, the vibration damping performance of the secondary damper 15 (centrifugal pendulum damper) is improved by increasing the engine speed.

  Therefore, the vibration damping performance by the secondary damper 15 and the vibration damping performance by the toroidal transmission mechanism 18 complement each other to obtain the necessary vibration damping performance in a wide engine speed range from the start of the vehicle to the high speed cruise. It is possible to improve the vibration and noise performance of the vehicle.

  In the graph of FIG. 5, the vertical axis is the engine speed and the horizontal axis is the axle speed, the OALow line indicates the LOW ratio of the entire continuously variable transmission T, and the OAHigh line indicates the entire continuously variable transmission T. HI ratio is shown. The engine speed N1 line is a line in which the damping performance of the secondary damper 15 (centrifugal pendulum damper) deteriorates at the lower engine speed. The line of the ratio R1 is a line where the vibration transmissibility decreases due to an increase in the equivalent inertia of the toroidal transmission mechanism 18 on the lower side.

  According to the present embodiment, since the toroidal transmission mechanism 18 has a two-stage configuration and has a wide range, the OAHigh line moves greatly below the ratio R1 line, and the equivalent inertia of the toroidal transmission mechanism 18 The shaded area where the vibration transmissibility decreases due to an increase in the frequency is greatly expanded. As a result, much of the region where the vibration damping performance of the secondary damper 15 on the lower side of the engine speed N1 line deteriorates is compensated by a decrease in vibration transmission rate due to an increase in the equivalent inertia of the toroidal transmission mechanism 18, and a wide engine speed The vibration and noise performance of the vehicle can be improved in several areas.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the continuously variable transmission T according to the embodiment includes the driving force integration mechanism 17, but the driving force integration mechanism 17 is not necessarily required.

  The drive source of the present invention is not limited to the engine E of the embodiment, and may be another type of drive source such as an electric motor.

12 Input shaft (rotary shaft)
15 Secondary damper (centrifugal pendulum damper)
18 Toroidal transmission mechanism 27 Input disk 28 Output disk 29 Intermediate disk 30 First power roller 31 Second power roller E Engine (drive source)
W drive wheel

Claims (1)

A vehicle power transmission device that transmits a driving force of a driving source (E) to driving wheels (W) via a centrifugal pendulum damper (15) and a toroidal transmission mechanism (18),
The toroidal transmission mechanism (18) includes a rotary shaft (12) to which a driving force from the centrifugal pendulum damper (15) is input, an input disk (27) that rotates together with the rotary shaft (12), and the rotation An output disk (28) supported to be rotatable relative to the shaft (12), and an intermediate disk supported to be rotatable relative to the rotating shaft (12) between the input disk (27) and the output disk (28). (29), the first power roller (30) sandwiched between the input disk (27) and the intermediate disk (29), and the intermediate disk (29) and the output disk (28). A vehicle power transmission device comprising a second power roller (31).

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