JP6685770B2 - Torque converter - Google Patents

Description

  The present invention relates to a torque converter.

  In a vehicle equipped with an automatic transmission, the power from the engine is input to the automatic transmission via a torque converter, and the power shifted by the automatic transmission is transmitted to the drive wheels.

  The torque converter includes a front cover, a pump impeller, and a turbine runner. The front cover and the pump impeller are fixed to each other to form a space therebetween. The turbine runner is housed in a space between the front cover and the pump impeller, and is provided so as to be rotatable relative to the front cover and the pump impeller about the same rotation axis.

  Power from the engine is input to the front cover. The front cover and the pump impeller rotate integrally with the input power. When the pump impeller rotates, a flow of oil from the pump impeller to the turbine runner occurs. This flow of oil is received by the turbine runner, and the turbine runner rotates. At this time, a power amplification action occurs. An input shaft of the automatic transmission is connected to the turbine runner so as not to rotate relative to it. When the turbine runner rotates, the input shaft of the automatic transmission rotates together with the turbine runner, whereby power is transmitted from the torque converter to the automatic transmission.

  In order to improve the fuel consumption of the vehicle by improving the torque transmission efficiency of the torque converter, many torque converters incorporate a lockup mechanism for directly connecting the pump impeller and the turbine runner. The lockup mechanism includes a lockup piston arranged between the front cover and the turbine runner. A friction material is attached to the surface of the lock-up piston facing the front cover. The hydraulic pressure moves the lock-up piston to the front cover side, and the friction material is pressed against the inner surface of the front cover. It is transmitted directly.

  Further, the lock-up mechanism is provided with a damper mechanism for damping vibrations from the engine when the pump impeller and the turbine runner are directly connected. The damper mechanism includes a retaining plate fixed to the lock-up piston, a spring supported by the retaining plate, and a driven plate elastically connected to the retaining plate in the rotation direction via the spring. There is. The driven plate is fixed to the turbine runner. Vibrations input from the engine are damped by the spring repeatedly compressing and restoring between the retaining plate and the driven plate.

  As the spring of the damper mechanism, a straight spring having a linear shape in a free state or an arc spring having an arc shape in a free state is used. For example, by using an arc spring, spring characteristics (damper characteristics) having low rigidity and a wide twist angle can be obtained.

JP, 2015-98928, A

  When the middle part of the spring approaches the outer side in the radial direction due to the compression of the spring during vibration damping, the spring slides on the outer peripheral restraint member surrounding the outer periphery of the spring, and friction resistance due to the sliding, that is, hysteresis torque is generated. When the hysteresis torque is generated, the vibration damping effect of the damper mechanism (spring) is weakened, so that the noise vibration characteristic of the vehicle may be deteriorated.

  An object of the present invention is to provide a torque converter that can reduce hysteresis torque.

  To achieve the above object, a torque converter according to the present invention includes a front cover to which power is input, a pump impeller fixed to the front cover and forming a space between the front cover, the front cover and the pump impeller. A turbine runner housed in the space between the front cover and the turbine runner, and a lock-up piston that is integrally rotatable with the turbine runner and directly connects / separates the front cover and the turbine runner by pressure contact / separation with the front cover; A retaining plate fixed to the piston, a spring supported by the retaining plate, a driven plate fixed to the turbine runner and elastically connected to the retaining plate in the rotational direction via the spring, and a spring. And an outer peripheral member that surrounds the outer periphery of Has a structure in which a first spring having a relatively small spring constant and a second spring having a relatively large spring constant are connected with a spring seat interposed therebetween, and the spring seat is corotatably coupled to the outer peripheral member. There is.

  With this configuration, the vibration input to the front cover is damped by the spring repeatedly compressing and restoring between the retaining plate and the driven plate.

  When the driven plate twists from the second spring toward the first spring, the first spring and the second spring are compressed by the combined spring constant of the first spring and the second spring, and the spring characteristic (damper characteristic) becomes 1 It becomes the characteristic of the step. In the characteristic of the first stage, as shown in FIG. 3, the torque required for twisting increases relatively gently as the twist angle increases. Since the first spring is compressed, the spring seat interposed between the first spring and the second spring rotates, and the outer peripheral member rotates together with the spring seat. Therefore, compared with the case where the outer peripheral member is stationary, the frictional resistance (sliding resistance) when the first spring and the second spring slide on the outer peripheral member is reduced. As a result, the hysteresis torque can be reduced.

  When the first spring is twisted until it is no longer compressed, only the second spring is compressed thereafter. Therefore, the spring characteristic becomes the second stage characteristic. In the characteristic of the second step, the stopper torque has a required twist angle at a higher spring constant than that of the first step. Therefore, as shown in FIG. 3, the torque required for the twist is relatively large as the twist angle increases. It rises sharply.

  The first spring and the second spring are preferably arc springs.

  Thereby, when the first spring and the second spring are compressed, it is possible to prevent the respective intermediate portions of the first spring and the second spring from being pushed outward in the radial direction. Further, it is possible to obtain spring characteristics having low rigidity and a wide twist angle.

  According to the present invention, hysteresis torque can be reduced. Further, it is possible to obtain a spring characteristic of two stages. Therefore, the vibration input to the torque converter can be effectively damped, and noise vibration of the vehicle can be reduced.

It is a sectional view of a torque converter concerning one embodiment of the present invention. It is a figure which shows the structure of a damper mechanism typically. It is a figure which shows a spring characteristic (damper characteristic).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Structure of torque converter>
FIG. 1 is a cross-sectional view of a torque converter 1 according to an embodiment of the present invention taken along a plane including a rotation center line C. In FIG. 1, hatching showing a cross section is omitted.

  The torque converter 1 is interposed between the engine and the automatic transmission and transmits the power of the engine to the input shaft 2 of the automatic transmission.

  The torque converter 1 includes a front cover 11, a pump impeller 12, a turbine hub 13, a turbine runner 14, and a lockup mechanism 15.

  The front cover 11 is connected to an output shaft (not shown) of the engine. As a result, the power from the engine is input to the front cover 11.

  The pump impeller 12 is fixed to the front cover 11, and is rotated integrally with the front cover 11 by the driving force input to the front cover 11. An oil chamber 16 filled with oil (ATF: Automatic Transmission Fluid) is formed between the front cover 11 and the pump impeller 12. A plurality of blades 17 are radially arranged on the inner surface (the surface on the oil chamber 16 side) of the pump impeller 12.

  The turbine hub 13 is housed in the oil chamber 16. The turbine hub 13 integrally has a substantially cylindrical boss portion 18 and a flange portion 19 that extends radially outward from the boss portion 18. The input shaft 2 of the automatic transmission is inserted through the oil chamber 16 along the rotation center line C, and the boss portion 18 is externally fitted to the input shaft 2 and spline-fitted to the input shaft 2. .

  The turbine runner 14 is fixed to a surface of the flange portion 19 of the turbine hub 13 on the pump impeller 12 side. On the surface of the turbine runner 14 facing the pump impeller 12, a plurality of blades 20 are radially arranged side by side.

  The lockup mechanism 15 includes a lockup piston 21 and a damper mechanism 22.

  The lock-up piston 21 has a substantially annular plate shape, and the inner periphery thereof is externally fitted to the flange portion 19 of the turbine hub 13 and is located between the front cover 11 and the turbine runner 14. When the hydraulic pressure on the turbine runner 14 side with respect to the lockup piston 21 is higher than the hydraulic pressure on the front cover 11 side, the differential pressure causes the lockup piston 21 to move to the front cover 11 side. When the hydraulic pressure on the front cover 11 side with respect to the lockup piston 21 is higher than the hydraulic pressure on the turbine runner 14 side, the differential pressure causes the lockup piston 21 to move to the turbine runner 14 side.

  A friction material F is attached to the outer peripheral end portion of the surface of the lockup piston 21 on the front cover 11 side. When the lockup piston 21 is moved to the front cover 11 side by the hydraulic pressure and the friction material F is pressed against the front cover 11, the pump impeller 12 and the turbine runner 14 are directly connected, and the power from the engine is input to the automatic transmission. It is transmitted directly to the shaft 2.

  FIG. 2 is a diagram schematically showing the configuration of the damper mechanism 22.

  The damper mechanism 22 is a mechanism for damping the vibration from the engine when the pump impeller 12 and the turbine runner 14 are directly connected. As shown in FIG. 1, the damper mechanism 22 includes a retaining plate 23 supported by the lock-up piston 21, a spring 24 supported by the retaining plate 23, and a retaining plate in the rotational direction via the spring 24. A driven plate 25 that is elastically connected to 23 and an outer peripheral member 26 that surrounds the outer periphery of the spring 24 are provided.

  The retaining plate 23 is provided on the turbine runner 14 side with respect to the lockup piston 21. The retaining plate 23 integrally includes a fixing portion 31 and a plurality of (three in this embodiment) supporting portions 32. The fixed portion 31 has a substantially annular plate shape, and an inner peripheral end portion thereof is fixed to the lockup piston 21. The plurality of support portions 32 are arranged at equal angular intervals, and each support portion 32 extends radially outward from the fixed portion 31. Each support portion 32 has a substantially C-shape that is open toward the turbine runner 14 side.

  As shown in FIG. 2, the springs 24 are provided in the same number as the number of the support portions 32 of the retaining plate 23, with the first spring 33 and the second spring 34 as one set. The first spring 33 and the second spring 34 are arc springs that arc in a free state. The spring constant of the first spring 33 is smaller than the spring constant of the second spring 34.

  The first spring 33 and the second spring 34 forming a set are connected with a spring seat 35 interposed therebetween. Specifically, the end portion 36 on one side in the circumferential direction of the first spring 33 and the end portion 37 on the other side in the circumferential direction of the second spring 34 forming a pair with the first spring 33 are the end portions 36, 37. It is fixed to a spring seat 35 interposed therebetween. A spring seat 38 is attached to the end of the first spring 33 opposite to the spring seat 35 side. The spring seat 38 is fixed to the retaining plate 23. A spring seat 39 is attached to the end of the second spring 34 opposite to the spring seat 35 side.

  The driven plate 25 is a plate member having a substantially annular plate shape, and is fixed to the turbine runner 14. On the outer periphery of the driven plate 25, the same number of contact portions 41 as the number of the support portions 32 of the retaining plate 23 are formed at equal angular intervals. The contact portion 41 extends from the outer peripheral end of the driven plate 25 toward the retaining plate 23 side and enters the support portion 32 of the retaining plate 23.

  The outer peripheral member 26 is provided between the lock-up piston 21 and the retaining plate 23, as shown in FIG. 1. The outer peripheral member 26 integrally includes an interposition part 42 extending substantially along the outer peripheral end of the lockup piston 21, and an outer peripheral receiving part 43 extending from the interposition part 42 to the turbine runner 14 side and surrounding the outer periphery of the spring 24. Have An opening 44 is formed in the interposition portion 42 at a portion facing the spring 24, and a part of the spring 24 is fitted in the opening 44. The spring seat 35 sandwiched between the first spring 33 and the second spring 34 is provided with a substantially rectangular fitting portion 45 that projects outward in the radial direction, and the fitting portion 45 has an outer circumference receiving portion 43. It is fitted in the fitting hole 46 formed in the. Accordingly, the spring seat 35 is coupled to the outer peripheral member 26 so as to be able to rotate together.

  The fitting portion 45 may be fitted into the fitting hole 46 in a press-fitted state, or may be welded to the outer peripheral receiving portion 43 while fitted in the fitting hole 46.

<Effect>
With the above configuration, the vibration input to the front cover 11 is damped by the spring 24 repeatedly compressing and restoring between the retaining plate 23 and the driven plate 25.

  When the driven plate 25 twists the side from the second spring 34 toward the first spring 33, that is, clockwise, in FIG. 2, the combined spring constant of the first spring 33 and the second spring 34 causes the first spring 33 and the second spring 34 to move. The spring 34 is compressed, and the spring characteristic (damper characteristic) becomes the first stage characteristic. In the characteristic of the first stage, as shown in FIG. 3, the torque required for twisting increases relatively gently as the twist angle increases. Since the first spring 33 is compressed, the spring seat 35 interposed between the first spring 33 and the second spring 34 rotates, and the outer peripheral member 26 rotates together with the spring seat 35. Therefore, compared with the case where the outer peripheral member 26 is stationary, the frictional resistance (sliding resistance) when the first spring 33 and the second spring 34 slide on the outer peripheral receiving portion 43 of the outer peripheral member 26 is reduced. It As a result, the hysteresis torque can be reduced.

  When the first spring 33 is twisted until it is no longer compressed, only the second spring 34 is compressed thereafter. Therefore, the spring characteristic becomes the second stage characteristic. In the characteristic of the second step, since the stopper torque has a required twist angle at a spring constant higher than that of the first step, as shown in FIG. 3, the torque required for the twist is relatively increased as the twist angle increases. It rises sharply.

  The first spring 33 and the second spring 34 are arc springs. Therefore, when the first spring 33 and the second spring 34 are compressed, it is possible to suppress the intermediate portions of the first spring 33 and the second spring 34 from bulging outward in the radial direction. Further, it is possible to obtain spring characteristics having low rigidity and a wide twist angle.

  Therefore, the vibration input to the torque converter 1 can be effectively damped, and the noise vibration of the vehicle can be reduced.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms.

  For example, although the configuration in which the first spring 33 and the second spring 34 are arc springs has been taken up, a straight spring that is linear in a free state may be used as the first spring 33 and the second spring 34.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1 Torque Converter 11 Front Cover 12 Pump Impeller 13 Turbine Hub 14 Turbine Runner 21 Lockup Piston 23 Retaining Plate 24 Spring 25 Driven Plate 26 Peripheral Member 33 First Spring 34 Second Spring 35 Spring Seat

Claims (1)

A front cover to which power is input,
A pump impeller fixed to the front cover and forming a space between the front cover and the front cover,
A turbine runner housed in the space between the front cover and the pump impeller,
A lock-up piston that is provided integrally with the turbine runner so as to be rotatable, and directly connects / separates the front cover and the turbine runner by pressure contact / separation with the front cover,
A retaining plate fixed to the lock-up piston,
A spring supported by the retaining plate,
A driven plate that is fixed to the turbine runner and is elastically connected to the retaining plate in the rotational direction via the spring,
An outer peripheral member surrounding the outer periphery of the spring,
The spring has a structure in which a first spring having a relatively small spring constant and a second spring having a relatively large spring constant are connected with a spring seat interposed therebetween.
The spring seat is rotatably coupled to the outer peripheral member ,
The outer peripheral member integrally has an outer peripheral receiving portion surrounding the outer periphery of the spring,
A fitting portion is formed on the spring seat,
The torque converter, wherein the fitting portion is fitted in a fitting hole formed in the outer peripheral receiving portion .

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