JP2012013206A - Torque converter with lock-up clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque converter with a lock-up clutch, in which temperature rise of an annular friction material upon slipping of the lock-up clutch is effectively suppressed.SOLUTION: The torque converter with the lock-up clutch includes oil passage grooves 64 as temperature rise suppressing means 62 for suppressing the temperature rise of regions, of a front cover 22, where set blocks 16 are fixed and surrounding regions thereof. Each of the oil passage groove 64 is formed on a circumferential region of the front cover 22, the region being corresponding to the set block 16 located at an opposite surface where the front cover 22 is opposite to the annular friction material 50 and the region being positioned at a back side part in the rotation direction of the front cover 22, and the oil passage groove 64 permits the passage of a hydraulic fluid from a lock-up engagement side oil chamber 42 to a lock-up release side oil chamber 58. Consequently, the hydraulic fluid flows through the oil passage groove 64 upon the slip working, thereby, the part having the maximum amount of heat generation in the front cover 22 is cooled and, thereby, the temperature rise of the annular friction material 50 can be effectively suppressed.

Description

  The present invention relates to a torque converter including a lockup clutch that is operated by a pressure difference between a lockup engagement side oil chamber and a lockup release side oil chamber.

  By adjusting the pressure difference between the lockup engagement side oil chamber and the lockup release side oil chamber, the clutch piston that rotates integrally with the turbine runner and the front cover can be slip-engaged via the annular friction material. A lock-up clutch engaged with the clutch piston, and the front cover pressed by the clutch piston via the annular friction material from the opposite side of the clutch piston and the annular friction material, and the front cover is driven by a power source In order to connect to the output rotating member, there is known a torque converter including connecting members fixed to a plurality of portions of the outer peripheral portion of the front cover. For example, those described in Patent Documents 1 to 5. In such a torque converter, the heat resistance of the annular friction material has been improved in order to expand the slip control operation region of the lock-up clutch and improve the vehicle fuel efficiency. There were limits. Therefore, in order to increase the slip control operation area of the lockup clutch and improve the vehicle fuel efficiency as described above, it is desirable to minimize the temperature increase of the annular friction material based on the frictional heat at the time of slipping. It is.

JP 2008-190561 A JP 2008-185103 A JP 2007-051779 A JP-A-5-187517 JP 2000-88079 A

  On the other hand, Patent Document 1 proposes a torque converter including two types of friction materials, a slip friction material and a fastening friction material. The slip friction material is provided with a plurality of communication grooves that communicate between the outer peripheral side and the inner peripheral side, and when the lockup clutch slips, hydraulic oil flows into the plurality of communication holes, so that the slip friction material And the frictional heat generated between the clutch piston and the clutch piston can be released. However, in such a torque converter, the size of the communication groove is limited in order to secure the fastening force at the time of clutch engagement, so that the temperature increase of the annular friction material at the time of slipping of the lockup clutch is not necessarily sufficiently suppressed. I couldn't.

  Patent Document 2 proposes a torque converter including a clutch piston having a main piston and a sub-piston divided into two in the axial direction. The sub-piston is provided so as to be rotatable relative to the main piston around the axis and movable in the direction of the axis. When the lock-up clutch slips, the sub-piston is engaged with the main piston so that an annular friction material is obtained. It is supposed that the frictional heat generated between the main piston and the main piston can be released to the sub piston. However, in such a torque converter, there is a limit to the space for providing the sub-piston, and the temperature increase of the annular friction material at the time of slipping of the lockup clutch cannot always be sufficiently suppressed.

  Patent Document 3 discloses a friction plate that is fixed to the front cover between the annular friction material and the front cover, and has an oil passage that communicates the outer peripheral side and the inner peripheral side on the surface facing the front cover. Proposed torque converters have been proposed. The friction plate is said to be able to release frictional heat generated between the friction plate and the annular friction material when hydraulic oil flows through the oil passage when the lockup clutch slips. However, such a torque converter has a disadvantage that the number of parts increases, the configuration becomes complicated, and the cost becomes high.

  Patent Document 4 proposes a torque converter having a plurality of cutout grooves formed on the surface of the annular friction material facing the front cover and opened to the outer peripheral side. It is said that the frictional heat generated between the annular friction material and the front cover can be released by the hydraulic oil entering the notch groove when the lockup clutch slips. However, in such a torque converter, the notch groove does not penetrate in the radial direction, the amount of hydraulic oil entering is not sufficient, and the temperature rise of the annular friction material when the lockup clutch slips is not necessarily sufficiently suppressed. I couldn't.

  In Patent Document 5, a first annular friction material fixed on the surface of the clutch piston facing the front cover, and an outer peripheral side of the first annular friction material are fixed on the surface of the front cover facing the clutch piston. A torque converter including a second annular friction material has been proposed. According to this torque converter, the friction area when the lock-up clutch slips is increased, and the frictional heat generated during the slip can be reduced. However, in such a torque converter, there is a limit to the space where the second annular friction material is provided, and the temperature increase of the annular friction material when the lockup clutch slips cannot always be sufficiently suppressed.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to provide a torque with a lock-up clutch that can more effectively suppress the temperature increase of the annular friction material when the lock-up clutch slips. To provide a converter.

  As a result of repeated studies on the background of the above circumstances, the present inventors have found that the surface pressure between the front cover and the annular friction material is caused by the clutch piston of the front cover when the lockup clutch slips. It has been found that the portion of the pressed front cover supported by the connecting member on the side opposite to the clutch piston is relatively large. When the lock-up clutch slips, the temperature distribution of the front cover varies depending on the circumferential position, and the amount of heat generated in the portion of the front cover where the connecting member is fixed and its peripheral portion is relatively large (high). I found out. Furthermore, when the lockup clutch slips, it has been found that the amount of heat generated at the rear portion in the rotational direction of the front cover is the largest (high) among the portion where the connecting member is fixed and its peripheral portion. The present invention has been made based on such findings.

  That is, the gist of the invention according to claim 1 is that (a-1) the pressure difference between the lockup engagement side oil chamber and the lockup release side oil chamber is adjusted, so that the turbine runner is integrated. A lock-up clutch that engages a clutch piston that rotates in a slipping manner with a front cover so as to be slip-engageable via an annular friction material, and (a-2) the front pressed by the clutch piston via the annular friction material A connecting member that supports the cover from the side opposite to the clutch piston and the annular friction member, and is fixed to a plurality of portions on the outer peripheral portion of the front cover in order to connect the front cover to the output rotating member of the driving force source. (B) suppresses a temperature rise in a portion of the front cover to which the connecting member is fixed and a peripheral portion thereof. It is in having a temperature rise suppression means for this.

  According to a second aspect of the present invention, in the first aspect of the invention, the temperature rise suppression means includes the connecting member and its connecting member of the front cover facing the annular friction material. A part of the circumferential portion corresponding to the periphery is formed from the inner peripheral side to the outer peripheral side of the annular friction material, and the working oil from the lockup engagement side oil chamber to the lockup release side oil chamber It is an oil distribution groove that enables distribution.

  Further, the gist of the invention according to claim 3 is that, in the invention according to claim 2, the oil circulation groove is formed on the coupling member and its periphery in the surface of the front cover facing the annular friction material. It is located in the rotation direction rear part of the said front cover of the circumferential direction part corresponding to this.

  According to a fourth aspect of the present invention, there is provided the invention according to the first aspect, wherein: (a) the annular friction material is adhered to a side surface of the front cover on the clutch piston side; And at least a part of a circumferential portion corresponding to the periphery thereof has a radially enlarged portion formed by locally expanding in the radial direction, and (b) the temperature rise suppression means has a diameter of the annular friction material. It is to be constituted by a direction expanding part.

  Further, the gist of the invention according to claim 5 is that, in the invention according to claim 4, the radially enlarged portion of the annular friction material corresponds to the connecting member and the periphery thereof in the annular friction material. It exists in the rotation direction rear part of the said front cover of the circumferential part.

  According to a sixth aspect of the present invention, in the first aspect of the invention, the temperature rise suppressing means has one end joined to a part of the peripheral portion of the connecting member of the front cover. In addition, the other end is joined to a portion of the front cover other than the peripheral portion, and is a heat conducting member for releasing the heat of the peripheral portion to a portion other than the peripheral portion.

  Further, the gist of the invention according to claim 7 is that, in the invention according to claim 6, one end of the heat conducting member is a rotation of the front cover at a peripheral portion of the connecting member of the front cover. It exists in being joined to the direction rear part.

  The gist of the invention according to claim 8 is that, in the invention according to claim 7, the heat conducting member is made of a member having a thermal conductivity larger than that of the front cover.

  A gist of the invention according to claim 9 is that, in the invention according to claim 1, the temperature rise suppression means is configured such that the temperature of a part of the peripheral portion of the connecting member of the front cover is predetermined. When the predetermined high temperature state is reached, slip engagement of the lock-up clutch is stopped.

  A gist of the invention according to claim 10 is that, in the invention according to claim 9, (a) the peripheral portion of the connecting member of the front cover is adhered to the rear portion in the rotational direction of the front cover. , A light output member that outputs light having a wavelength or intensity corresponding to the temperature of the rear portion in the rotation direction being equal to or higher than a predetermined slip prohibiting temperature, and detecting light emitted by the light output member (B) the temperature rise suppression means stops the slip engagement of the lockup clutch when the optical sensor detects light emitted by the light output member. There is.

  According to the torque converter with a lock-up clutch according to the first aspect of the present invention, the temperature increase suppressing means for suppressing the temperature increase in the portion of the front cover where the connecting member is fixed and the peripheral portion thereof is provided. Therefore, when the lockup clutch slips, the temperature rise in the portion of the front cover where the heat generation amount is relatively large is intensively suppressed. For example, the heat generation amount is reduced by suppressing the temperature increase in the entire front cover. Compared with the case where the temperature increase suppressing effect of the relatively large portion is relatively weak, the temperature increase of the annular friction material at the time of slipping of the lockup clutch can be more effectively suppressed. By suppressing the temperature rise in the part of the front cover where the heat generation is large, the temperature of the annular friction material becomes difficult to reach the predetermined slip prohibition temperature, and the slip control operating range of the lockup clutch is further expanded. Therefore, the vehicle fuel consumption can be improved.

  According to the torque converter with a lock-up clutch of the invention according to claim 2, the temperature rise suppression means is a circumferential portion corresponding to the connecting member and the periphery thereof on the surface of the front cover facing the annular friction material. An oil distribution groove formed in a part of the annular friction material from the inner peripheral side to the outer peripheral side, and allows the hydraulic oil to flow from the lockup engagement side oil chamber to the lockup release side oil chamber. Therefore, when the lockup clutch slips, the temperature rise in the portion of the front cover where the heat generation amount is relatively large is suppressed by the hydraulic oil flowing through the oil distribution groove. The temperature rise of the annular friction material at the time of slip can be suppressed effectively. Here, in order to secure the fastening force at the time of clutch engagement, the size of the oil circulation groove is limited, but when the upper limit of the area ratio of the oil circulation groove to the friction surface is determined, the front cover When the oil circulation groove is intensively provided in a portion having a relatively large calorific value, it is more effective than the case where the oil circulation groove is provided in addition to the portion having a relatively large calorific value. An increase in temperature of the annular friction material can be suppressed.

  According to the torque converter with a lockup clutch of the invention according to claim 3, the oil circulation groove is formed in a circumferential portion corresponding to the connecting member and the periphery thereof in the surface facing the annular friction material of the front cover. Since the front cover is located at the rear portion in the rotational direction, the temperature rise of the portion of the front cover where the heat generation amount is the largest is suppressed by flowing the hydraulic oil through the oil circulation groove when the lockup clutch slips. Therefore, the temperature rise of the annular friction material when the lockup clutch slips can be more effectively suppressed.

  According to the torque converter with a lock-up clutch of the invention according to claim 4, the annular friction material is adhered to the side surface of the front cover on the clutch piston side, and at least the circumferential portion corresponding to the connecting member and its periphery. Since the part having a radially expanded part formed by locally expanding in the radial direction and the temperature rise suppression means is constituted by the radially expanded part of the annular friction material, The frictional area of the circumferential portion where the amount of heat generated during the slip is relatively large is increased, and the heat generation in the circumferential portion is suppressed, so the manufacturing cost of the annular friction material is reduced while the annular friction material is An increase in temperature can be effectively suppressed.

  According to the torque converter with a lock-up clutch according to the fifth aspect of the present invention, the radially expanded portion of the annular friction material includes a front portion of a circumferential portion corresponding to the connecting member and the periphery of the annular friction material. Since the cover is located at the rear part in the rotational direction, the frictional area of the circumferential part where the amount of heat generation is maximized when the lock-up clutch slips is increased, and the heat generation in the circumferential part is suppressed. While suppressing the manufacturing cost of the material, the temperature increase of the annular friction material at the time of slip can be effectively suppressed.

  According to the torque converter with a lockup clutch of the invention according to claim 6, the temperature rise suppression means has one end joined to a part of the peripheral portion of the connecting member of the front cover and the other end. Part is joined to a part of the front cover other than the peripheral part and is a heat conducting member for releasing the heat of the peripheral part to a part other than the peripheral part. Since heat in a portion of the cover that generates a relatively large amount of heat is released to other portions, the temperature increase of the annular friction material during slippage of the lockup clutch can be effectively suppressed.

  According to the torque converter with a lockup clutch of the invention according to claim 7, one end portion of the heat conducting member is joined to a rear portion in the rotational direction of the front cover in the peripheral portion of the connecting member of the front cover. Therefore, when the lock-up clutch slips, the heat in the circumferential direction that generates the largest amount of heat is released to others, and the temperature rise in the circumferential part is suppressed. The temperature rise of the material can be more effectively suppressed.

  According to the torque converter with a lockup clutch of the invention according to claim 8, since the heat conducting member is made of a member having a thermal conductivity larger than that of the front cover, a heat generation amount is generated when the lockup clutch slips. Since the heat in the large circumferential portion is actively released to the other, the temperature increase of the annular friction material at the time of slipping of the lockup clutch can be further effectively suppressed.

  According to the torque converter with a lockup clutch of the invention according to claim 9, the temperature rise suppression means is a predetermined high temperature state in which the temperature of a part of the peripheral portion of the connecting member of the front cover is predetermined. In this case, since the slip engagement of the lock-up clutch is stopped, the temperature of the annular friction material is predicted based on, for example, the vehicle speed and the accelerator opening degree from a relationship obtained experimentally in advance. Compared with the case where the slip engagement of the lock-up clutch is stopped when the predicted temperature exceeds the predetermined slip prohibition temperature, the temperature of the annular friction material can be grasped more accurately, and the safety Therefore, it is not necessary to set the lock control clutch slip control operating range to a smaller value. It can be more enlarged, thereby improving the vehicle fuel economy.

  According to the torque converter with a lock-up clutch according to the tenth aspect of the invention, the front cover is bonded to the rear portion in the rotational direction of the front cover at the peripheral portion of the connecting member, and the temperature of the rear portion in the rotational direction is A light output member that outputs light having a wavelength or intensity corresponding to being above a predetermined slip prohibition temperature as self-emission or reflected light, and an optical sensor that detects light emitted by the light output member, and the temperature The rise suppressing means stops the slip engagement of the lockup clutch when the light sensor detects the light emitted from the light output member, so that the temperature of the annular friction material is accurately grasped. The slip control operating area of the lockup clutch can be expanded.

FIG. 1 is a diagram showing a torque converter 10 with a lockup clutch for a vehicle according to an embodiment of the present invention. It is a figure which shows the front cover and set block of the II arrow part of FIG. It is an expanded sectional view which expands and shows the annular friction material of FIG. 1, and its vicinity. It is the figure which looked at the front cover shown in FIG. 2 from the back side. It is sectional drawing which expands and shows a part of torque converter of the other Example of this invention, and is equivalent to FIG. FIG. 6 is a diagram illustrating a front cover, a set block, and an annular friction material at a portion indicated by an arrow VI in FIG. 5, and corresponds to FIG. 4 in the first embodiment. It is a figure which shows a front cover and a set block among the torque converters of the other Example of this invention, Comprising: It is equivalent to FIG. It is sectional drawing which shows the torque converter of the other Example of this invention, and is equivalent to FIG. It is a figure which shows the front cover and set block of the IX arrow part of FIG. 8, and is equivalent to FIG. It is a flowchart explaining the principal part of the control action performed by the signal processing of the electronic controller of FIG.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a view showing a torque converter with a lockup clutch for vehicles (hereinafter referred to as a torque converter) 10 according to an embodiment of the present invention. The torque converter 10 is a fluid transmission device that is connected to an engine (not shown) as a driving force source of the vehicle and transmits the output of the engine to a transmission (not shown) connected to the rear stage side.

  The torque converter 10 in FIG. 1 includes a cover 18 that is connected to a drive plate 14 as an input rotation member via a set block 16 and is provided so as to be rotatable integrally with the drive plate 14. The drive plate 14 is connected to the crankshaft (output rotating member) 20 of the engine, and rotates by receiving the rotational force of the engine. The cover 18 is opposite to the front cover 22 disposed on the engine side (left side in FIG. 1), that is, the drive plate 14 side, and the transmission side (right side in FIG. 1), that is, the drive plate 14 of the front cover 22. The pump shell 24 disposed on the side is integrally connected by welding. The front cover 22 is a bottomed cylindrical member that opens on the opposite side to the drive plate 14, and the outer peripheral portion of the pump shell 24 is fitted into the inner peripheral surface of the opening and welded to each other.

  FIG. 2 is a view showing the front cover 22 and the set block 16 at the portion indicated by the arrow II in FIG. As shown in FIG. 2, six set blocks 16 are provided on the outer peripheral portion of the bottom wall portion 22a of the front cover 22 at equal intervals around the axis C1, and the outer peripheral portion and the inner peripheral portion are welded to each other. Is provided. As shown in FIG. 1, the set block 16 is fixed to a plurality of portions on the outer peripheral portion of the bottom wall portion 22a of the front cover 22 in order to connect the front cover 22 to the crankshaft 20 of the engine. This corresponds to the connecting portion in the present invention. Returning to FIG. 1, the drive plate 14 is provided to be rotatable integrally with the front cover 22 by being fastened to the set block 16 by bolts 25. In FIG. 2, a valley portion is indicated by a solid line among the peaks and valleys of the bottom wall portion 22 a of the portion indicated by the arrow II in FIG. 1.

  A pump impeller 26 and a turbine runner 28 are disposed in the cover 18 so as to face each other. The pump impeller 26 is fixed to the inner peripheral surface of the pump shell 24, and the turbine runner 28 is connected to the turbine shaft 32 via the turbine hub 30. When the pump impeller 26 is rotated by rotating the drive plate 14, the hydraulic oil in the torque converter 10 that is flowed by being energized by the blades of the pump impeller 26 acts on the blades of the turbine runner 28. Then, the turbine runner 28 is rotated to rotate the turbine shaft 32.

  A stator 38 connected to the stator shaft 36 via a one-way clutch 34 is provided between the pump impeller 26 and the turbine runner 28 so as to be rotatable in one direction. In the torque converter region, the hydraulic oil that has passed through the turbine runner 20 strikes the blades of the stator 38 and is changed in direction, and then circulated to the pump impeller 26.

  A clutch piston 40 is provided between the bottom wall portion 22a of the front cover 22 and the turbine runner 28 so as to be rotatable relative to the turbine hub 30 about the axis C1 and movable in the direction of the axis C1. The clutch piston 40 is provided so as to be able to approach and be separated from the side surface of the bottom wall portion 22a opposite to the set block 16. The space between the clutch piston 40 and the pump shell 24 forms a lockup engagement side oil chamber 42.

  A damper 44 is provided between the clutch piston 40 and the turbine hub 30. The damper 44 connects the clutch piston 40 and the turbine hub 30 via two types of coil springs 46 and 48, respectively. When the clutch piston 40 is rotated, the turbine shaft 32 connected to the turbine hub 30 is also rotated.

  An annular friction material 50 is affixed to a radial position corresponding to the set block 16 on the surface facing the bottom wall portion 22a of the clutch piston 40. The annular friction material 50 is made of a material having a low thermal conductivity, such as a material obtained by impregnating cellulose with a resin.

  A first oil passage 52 is formed between the pump shell 24 and the stator 38, and a second oil passage 54 is formed between the turbine hub 30 and the stator 38. The first oil passage 52 and the second oil passage 54 are communicated with each other by a gap between the pump impeller 26 and the stator 38, a gap between the stator 38 and the turbine runner 28, and the like. A third oil passage 56 is formed between the front cover 22 and the turbine hub 30. The third oil passage 56 extends from a hole 32 a formed in the turbine shaft 32 in the direction of the axis C <b> 1 to between the front cover 22 and the turbine hub 30 and between the front cover 22 and the clutch piston 40. It is an oil passage. A portion of the third oil passage 56 between the front cover 22 and the clutch piston 40 also functions as a lockup release side oil chamber 58.

  The clutch piston 40, the annular friction material 50, the lockup engagement side oil chamber 42, and the lockup release side oil chamber 58 constitute the lockup clutch 60. The lockup clutch 60 includes a clutch piston 40 that rotates integrally with the turbine runner 28 and the front cover 22 by adjusting a pressure difference between the lockup engagement side oil chamber 42 and the lockup release side oil chamber 58. Are engaged via an annular friction member 50 so as to be capable of slip engagement. It should be noted that the set block 16 causes the front cover 22 pressed by the clutch piston 40 via the annular friction material 50 when the lockup clutch 60 is engaged from the opposite side of the clutch piston 40 and the annular friction material 50. It functions as a supporting member to support.

  In the torque converter 10 configured as described above, for example, the lockup clutch 60 is completely engaged and the front cover 22 and the clutch piston 40 are directly connected based on the operating state of the vehicle in which the torque converter is mounted. The lockup control and the flexlockup control in which the lockup clutch 60 is slip-engaged (semi-engaged) and the front cover 22 and the clutch piston 40 are semi-directly connected are performed. By performing such control, transmission efficiency in the torque converter 10 is improved, and good vehicle fuel consumption can be obtained. Further, in the torque converter 10, when start of the vehicle is determined, flex start control is performed in which the power at the start is transmitted by controlling the slip state of the lockup clutch 60. By performing such control, the rotational speed of the engine, which is the driving force source of the vehicle, is maintained lower than usual, and an increase in the rotational speed of the engine is suppressed, and good fuel consumption can be obtained. . Whether the driving state of the vehicle is the driving state in which the above-described various controls are performed depends on whether the lock-up control region, the flex lock-up control region, and the flex start control region are in advance according to the accelerator opening and the vehicle speed, for example. The determination is made based on the accelerator opening and the vehicle speed from the set map.

  Here, when slip control such as flex lock-up control or flex start control is performed and the lock-up clutch 60 is slip-engaged, the portion of the front cover 22 corresponding to the set block 16 and the ring friction The surface pressure with the material 50 is larger than the surface pressure between the annular friction material 50 and the portion other than the portion corresponding to the set block 16 of the front cover 22. That is, when the lock-up clutch 60 slips, the surface pressure between the front cover 22 and the annular friction material 50 is such that the front cover 22 of the front cover 22 pressed by the clutch piston 40 is in contact with the clutch piston 40. The portion supported by the set block 16 on the opposite side is relatively large. For this reason, when the lock-up clutch 60 slips, the amount of heat generated in the portion of the front cover 22 where the set block 16 is fixed and its peripheral portion becomes relatively large. Further, the set block 16 is fixed. Among the portions and the peripheral portions thereof, the amount of heat generated at the rear portion in the rotational direction of the front cover 22 is the largest. The torque converter 10 according to the present embodiment includes a temperature increase suppression means 62 for suppressing a temperature increase in a portion of the front cover 22 where the set block 16 is fixed and its peripheral portion. Hereinafter, the temperature rise suppression means 62 will be described in detail.

  FIG. 3 is an enlarged cross-sectional view showing the annular friction material 50 and its vicinity in FIG. 1 in an enlarged manner. 4 is a view of the front cover 22 shown in FIG. 2 as viewed from the back side, that is, the pump shell 24 side. As shown in FIG. 3, the temperature rise suppression means 62 of the present embodiment is directed from the inner peripheral side to the outer peripheral side of the annular friction material 50 on the surface facing the annular friction material 50 of the bottom wall portion 22 a of the front cover 22. 3, and is constituted by an oil circulation groove 64 that allows the hydraulic oil to flow from the lockup engagement side oil chamber 42 to the lockup release side oil chamber 58 as indicated by an arrow b in FIG. 3. As shown in FIG. 4, the oil circulation groove 64 is a rear portion in the rotational direction of the front cover 22 indicated by an arrow “a” in the drawing, in the portion where the set block 16 of the front cover 22 is fixed and its peripheral portion. Is provided. In the present embodiment, six oil circulation grooves 64 are provided at equal intervals around the axis C1 corresponding to the set blocks 16 provided at equal intervals around the axis C1. In these oil circulation grooves 64, hydraulic oil circulates when the lock-up clutch 60 slips, and the front block 22 of the front cover 22 to which the set block 16 is fixed and its peripheral portion are indicated by arrows a in the figure. The rear part of the rotation direction of the cover 22 is cooled by the hydraulic oil so that the temperature rise is suppressed.

  The torque converter 10 with the lockup clutch of the present embodiment is a temperature rise suppression means 62 for suppressing the temperature rise of the portion of the front cover 22 where the set block (connecting member) 16 is fixed and its peripheral portion. An oil circulation groove 64 is provided. The oil circulation groove 64 is annular at the rear portion in the rotational direction of the front cover 22 among the circumferential direction portions corresponding to the set block 16 on the surface facing the annular friction material 50 of the bottom wall portion 22a of the front cover 22 and the periphery thereof. The friction material 50 is formed from the inner circumference side toward the outer circumference side, and allows the working oil to flow from the lockup engagement side oil chamber 42 to the lockup release side oil chamber 58. Therefore, when hydraulic oil flows through the oil circulation groove 64 when the lockup clutch 60 slips, the portion of the front cover 22 that generates the largest amount of heat is cooled. The temperature rise of the friction material 50 can be effectively suppressed. Here, in order to secure the fastening force at the time of clutch engagement, the size of the oil circulation groove 64 is limited, but when the upper limit of the area ratio of the oil circulation groove 64 to the friction surface is determined, When the oil circulation groove 64 is intensively provided in the portion of the front cover 22 where the heat generation amount is relatively large, compared to the case where the oil circulation groove 64 is provided in addition to the portion where the heat generation amount is relatively large. The temperature rise of the annular friction material 50 can be suppressed more effectively. In this way, the temperature increase of the portion of the front cover 22 where the heat generation amount is large is suppressed, so that the temperature of the annular friction material 50 does not easily reach a predetermined slip prohibition temperature, and the flex lock of the lockup clutch 60 Since the up control region and the flex start control region can be further expanded, the vehicle fuel consumption can be improved.

  Next, another embodiment of the present invention will be described. In the following description of the embodiments, portions that overlap each other are denoted by the same reference numerals and description thereof is omitted.

  FIG. 5 is an enlarged sectional view showing a part of a torque converter 70 according to another embodiment of the present invention, and corresponds to FIG. 3 in the first embodiment. FIG. 6 is a view showing the front cover 72, the set block 16, and the annular friction material 74 at the portion indicated by the arrow VI in FIG. 5, and corresponds to FIG. 4 in the first embodiment. The front cover 72 has the same configuration as the front cover 22 of the first embodiment except that the oil circulation groove 64 is not formed. As shown in FIG. 5, the annular friction material 74 is affixed to a radial position corresponding to the set block 16 on the surface facing the clutch piston 40 of the bottom wall portion 72 a of the front cover 72. The annular friction material 74 is made of a material having a low thermal conductivity such as a material in which a resin is impregnated with cellulose.

  As shown in FIG. 6, the annular friction material 74 is locally applied to a rear portion in the rotational direction of the front cover 22 indicated by an arrow a in the circumferential direction corresponding to the set block 16 and its periphery. It has a radially enlarged portion 74a formed to be enlarged in the radial direction. The temperature rise suppression means 76 of the present embodiment is constituted by a radially enlarged portion 74 a of the annular friction material 74. In the present embodiment, six radially enlarged portions 74a are provided at equal intervals around the axis C1 corresponding to the set blocks 16 provided at equal intervals around the axis C1. By these radially enlarged portions 74a, the frictional area of the circumferential portion of the annular friction material 74 where the amount of heat generation is to be maximized when the lockup clutch 60 slips is increased, and the heat generation in the circumferential portion is suppressed. It has come to be.

  The torque converter 70 with a lock-up clutch according to the present embodiment is a temperature rise suppression means 62 for suppressing a temperature rise in a portion of the front cover 22 where the set block (connecting member) 16 is fixed and its peripheral portion. A radially enlarged portion 74 a of the annular friction material 74 is provided. The radial direction enlarged portion 74a is formed by locally expanding the rotational direction rear portion of the front cover 22 of the circumferential portion corresponding to the set block 16 and its periphery in the annular friction material 74. It is. For this reason, the frictional area of the circumferential portion where the amount of heat generated when the lockup clutch 60 slips is maximized, and the heat generation in the circumferential portion is suppressed, so that the manufacturing cost of the annular friction material 50 is suppressed. The temperature rise of the annular friction material 74 when the lockup clutch 60 slips can be effectively suppressed. Therefore, the vehicle fuel efficiency can be improved as in the first embodiment.

  FIG. 7 is a view showing the front cover 82 and the set block 16 in the torque converter 80 according to another embodiment of the present invention, and corresponds to FIG. 2 in the first embodiment. The front cover 82 has the same shape as the front cover 22 of the first embodiment except that the oil circulation groove 64 is not formed.

  As shown in FIG. 7, one end of the front cover 82 is joined to a rear portion of the front cover 22 in the rotational direction indicated by an arrow a in the peripheral portion of the set block 16 of the bottom wall portion 82a. In addition, a heat conducting member 84 having the other end joined to the front cover 82 other than the peripheral portion of the set block 16 is provided. The heat conducting member 84 is a member having a thermal conductivity larger than that of the steel front cover 82, and is made of a graphite sheet. The heat conducting member 84 and the front cover 82 are joined by spot welding. The temperature rise suppression means 86 of the present embodiment is constituted by the heat conducting member 84. In the present embodiment, six heat conduction members 84 are provided at equal intervals around the axis C1 corresponding to the set blocks 16 provided at equal intervals around the axis C1. These heat conducting members 84 function as a part of the front cover 22 for releasing the heat of the portion where the amount of heat generation is greatest when the lockup clutch 60 slips to other than the peripheral portion of the set block 16.

  The torque converter 80 with a lock-up clutch according to the present embodiment is a temperature rise suppression means 86 for suppressing a temperature rise in the portion of the front cover 22 where the set block (connecting member) 16 is fixed and its peripheral portion. A heat conducting member 84 is provided. One end of the heat conducting member 84 is joined to the rear portion of the front cover 22 in the rotational direction of the front cover 22 in the peripheral portion of the set block 16 in the bottom wall portion 82 a of the front cover 82, and the other end is the front cover 82. Are joined to portions other than the peripheral portion of the set block 16. Therefore, when the lockup clutch 60 slips, the heat of the portion where the heat generation amount of the front cover 82 is the largest is released to the portion other than the peripheral portion of the set block 16, so that the temperature of the annular friction material 50 increases when the lockup clutch 60 slips. Can be effectively suppressed. Therefore, the vehicle fuel efficiency can be improved as in the first embodiment.

  Further, according to the torque converter 80 with the lockup clutch of the present embodiment, the heat conducting member 84 is made of a graphite sheet having a thermal conductivity larger than that of the steel front cover 82. Since the heat in the circumferential portion where the heat generation amount is large during the slip of 60 is positively released to the other, the temperature increase of the annular friction material 50 during the slip of the lockup clutch 60 can be further effectively suppressed.

  FIG. 8 is a sectional view showing a torque converter 90 according to another embodiment of the present invention, and corresponds to FIG. 1 in the first embodiment. The front cover 92 has the same shape as the front cover 22 of the first embodiment except that the oil circulation groove 64 is not formed. The torque converter 90 of the present embodiment stops the slip engagement of the lockup clutch 60 when the temperature of the peripheral portion of the set block 16 in the front cover 92 reaches a predetermined high temperature state. A temperature rise suppression means 94 is provided. Hereinafter, the temperature rise suppression means 94 will be described in detail.

  FIG. 9 is a view showing the front cover 92 and the set block 16 at the portion indicated by the arrow IX in FIG. 8, and corresponds to FIG. 2 in the first embodiment. As shown in FIG. 9, the front cover 92 is adhered to the rear portion in the rotational direction of the front cover 92 indicated by an arrow a in FIG. 9 in the peripheral portion of the set block 16, and as shown in FIG. 8, There is provided a phototransistor (light output member) 96 that self-emits light L having a wavelength or intensity corresponding to the temperature of the rear portion in the rotation direction being equal to or higher than, for example, a slip prohibition temperature set to about 200 degrees in advance. . As shown in FIG. 8, an optical sensor 100 that detects the light L emitted from the phototransistor 96 is provided on the inner peripheral surface of the housing 98 that houses the torque converter 90.

  When the optical sensor 100 detects the light L emitted from the optical transistor 96, a signal indicating that is supplied to the electronic control device 102. The electronic control unit 102 includes a so-called microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like, and functionally includes a lock-up control unit 104 and the temperature rise suppression unit 94. . The lockup control means 104 performs lockup control, flex lockup control, and flex start control according to the driving state when the driving state of the vehicle on which the torque converter 90 is mounted becomes a predetermined driving state. Each one is to be executed. Whether the driving state of the vehicle is the driving state in which the above-described various controls are performed is set in advance in the lockup control region, the flex lockup control region, and the flex start control region according to the accelerator opening and the vehicle speed. The determination is made based on the accelerator opening and the vehicle speed from the map.

  The temperature rise suppression means 94 stops slip engagement of the lockup clutch 60 when the optical sensor 100 detects the light L emitted from the optical transistor 96. That is, the temperature rise suppression means 94 is a case where the temperature of the rear portion in the rotational direction of the front cover 92 in the peripheral portion of the set block 16 of the front cover 92 is equal to or higher than the slip prohibition temperature set to about 200 degrees in advance, for example. In other words, the slip engagement of the lock-up clutch 60 is stopped to suppress the generation of frictional heat, thereby suppressing the temperature rise of the front cover 92 and the annular friction material 50.

  Here, the slip control operation region of the present embodiment, that is, the flex lockup control region and the flex start control region are set to be larger than the conventional one, but the driving state of the vehicle corresponds to the slip control operation region. Even when it is determined that the vehicle is in an operating state, if it is determined by the temperature rise suppression means 94 that the slip engagement of the lockup clutch 60 is to be stopped, the flex lockup control and the flex start control are stopped. It is configured to be.

  FIG. 10 is a flowchart for explaining a main part of the control operation executed by the signal processing of the electronic control unit 102, and is repeatedly executed with an extremely short cycle time of about several milliseconds to several tens of milliseconds, for example.

  In FIG. 10, in a step (hereinafter, “step” is omitted) S1 corresponding to the lockup control means 104, whether or not the driving state of the vehicle is a driving state corresponding to the flex lockup control region or the flexstart control region. Is determined.

  If the determination in S1 is negative, S1 and subsequent steps are repeatedly executed. If the determination in S1 is positive, the lockup clutch 60 is slipped in S2 corresponding to the lockup control means 104. The flex lockup control or flex start control to be engaged is executed.

  Next, in S3 corresponding to the temperature rise suppression means 94, it is determined whether or not the optical sensor 100 has detected the light L emitted from the optical transistor 96.

  When the determination at S3 is negative, the steps after S1 are repeatedly executed. When the determination at S3 is positive, the execution is started at S2 at S4 corresponding to the temperature rise suppression means 94. The flex lockup control or the flex start control is stopped, and this routine is terminated.

  According to the torque converter 90 with the lock-up clutch of the present embodiment, the peripheral portion of the set block 16 of the front cover 92 is adhered to the rear portion in the rotational direction of the front cover 92, and the temperature of the rear portion in the rotational direction is set in advance, for example, A phototransistor (light output member) 96 that self-emits light L having a wavelength or intensity corresponding to the slip prohibition temperature set to about 200 degrees or higher, and light that detects the light L emitted from the phototransistor 96 Since the sensor 100 and the optical sensor 100 detect the light L emitted from the phototransistor 96, the sensor 100 and the temperature rise suppression means 94 for stopping the slip engagement of the lockup clutch 60 are provided. For example, the temperature of the annular friction material 50 is predicted based on the vehicle speed, the accelerator opening, etc. Compared with the case where the slip engagement of the lock-up clutch 60 is stopped when the predicted temperature becomes equal to or higher than the predetermined slip prohibition temperature, the temperature of the annular friction material 50 can be grasped with higher accuracy, and safety can be ensured. Therefore, it is not necessary to set the slip control operation region of the lockup clutch 60 to be smaller in consideration of the characteristics, so that the slip control operation region of the lockup clutch 60 can be further expanded, and the vehicle fuel consumption can be improved.

  As mentioned above, although one Example of this invention was described in detail with reference to drawings, this invention is not limited to this Example, It can implement in another aspect.

  For example, in the first embodiment, the oil circulation groove 64 is provided in the rotation direction rear portion of the front cover 22 among the circumferential direction portions corresponding to the set block 16 of the front cover 22 and its periphery. It does not need to be provided in the direction rear part. A temporary effect can be obtained if the front cover 22 is provided on at least a part of the circumferential portion corresponding to the set block 16 and its periphery.

  In the second embodiment, the radially enlarged portion 74a is provided at the rear portion in the rotational direction of the front cover 72 among the circumferential portions corresponding to the set block 16 of the front cover 72 and its periphery. It does not need to be provided in the rear part in the rotation direction. A temporary effect can be obtained if the front cover 72 is provided on at least part of the circumferential portion corresponding to the set block 16 and its periphery.

  In the third embodiment, the heat conducting member 84 is configured to release heat from the rear portion in the rotational direction of the front cover 82 among the circumferential portions corresponding to the set block 16 of the front cover 82 and the periphery thereof. However, it does not necessarily have to be configured to allow the heat in the rear portion in the rotational direction to escape to the other. A temporary effect can be obtained if the configuration is such that a part of the heat in the circumferential portion corresponding to the set block 16 of the front cover 82 and its periphery is released to the other.

  Further, in the fourth embodiment, as the light output member, the light L having a wavelength or intensity corresponding to the temperature of the rear portion in the rotation direction of the peripheral portion of the set block 16 being equal to or higher than a predetermined slip prohibition temperature is self-emitted. Although the optical transistor 96 is provided, the present invention is not limited thereto, and for example, a light output member that outputs irradiation light from a predetermined light source as reflected light corresponding to the light L may be provided.

  It should be noted that the above description is merely an embodiment, and other examples are not illustrated. However, the present invention is implemented in variously modified and improved modes based on the knowledge of those skilled in the art without departing from the gist of the present invention. Can do.

10, 70, 80, 90: Torque converter with lock-up clutch 16: Set block (connection member)
20: Crankshaft (output rotating member)
22: front cover 28: turbine runner 40: clutch piston 42: lockup engagement side oil chamber 50: annular friction material 58: lockup release side oil chamber 60: lockup clutch 62, 76, 86, 94: temperature rise suppression Means 64: Oil circulation groove 74a: radially enlarged portion 84: heat conducting member 96: phototransistor (light output member)
100: Optical sensor

Claims (10)

By adjusting the pressure difference between the lockup engagement side oil chamber and the lockup release side oil chamber, the clutch piston that rotates integrally with the turbine runner and the front cover can be slip-engaged via the annular friction material. A lock-up clutch engaged with the clutch piston, and the front cover pressed by the clutch piston through the annular friction material from the opposite side of the clutch piston and the annular friction material, and driving the front cover A torque converter with a lock-up clutch, comprising: a coupling member fixed to a plurality of portions of the outer peripheral portion of the front cover for coupling to an output rotating member of a source;
A torque converter with a lock-up clutch, comprising: a temperature increase suppressing means for suppressing a temperature increase in a portion of the front cover where the connecting member is fixed and a peripheral portion thereof.   The temperature rise suppression means is provided on a part of a circumferential portion corresponding to the connecting member and the periphery thereof on a surface of the front cover facing the annular friction material, from an inner peripheral side to an outer peripheral side of the annular friction material. 2. An oil distribution groove formed toward the lock and enabling the flow of hydraulic oil from the lockup engagement side oil chamber to the lockup release side oil chamber. Torque converter.   The oil circulation groove is located in a rotation direction rear portion of the front cover of a circumferential portion corresponding to the connecting member and the periphery thereof on a surface of the front cover facing the annular friction material. The torque converter with a lock-up clutch according to claim 2. The annular friction material is attached to a side surface of the front cover on the clutch piston side, and is formed by locally expanding at least a part of a circumferential portion corresponding to the connection member and the periphery thereof. Having a radially enlarged portion,
The torque converter with a lockup clutch according to claim 1, wherein the temperature rise suppression means is configured by a radially enlarged portion of the annular friction material.   5. The radially expanded portion of the annular friction material is located in a rotation direction rear portion of the front cover of a circumferential portion corresponding to the connecting member and the periphery thereof in the annular friction material. Torque converter with lock-up clutch.   The temperature rise suppressing means has one end joined to a part of the peripheral part of the connecting member of the front cover and the other end joined to a part of the front cover other than the peripheral part. 2. The torque converter with a lock-up clutch according to claim 1, wherein the torque converter is a heat conducting member for releasing heat from the peripheral portion to a portion other than the peripheral portion.   7. The torque converter with a lockup clutch according to claim 6, wherein one end portion of the heat conducting member is joined to a rear portion of the front cover in the rotation direction of the peripheral portion of the connecting member. .   The torque converter with a lock-up clutch according to claim 6 or 7, wherein the heat conducting member comprises a member having a thermal conductivity larger than that of the front cover.   The temperature rise suppression means stops slip engagement of the lock-up clutch when the temperature of a part of the front cover in the vicinity of the connecting member reaches a predetermined high temperature state. The torque converter with a lock-up clutch according to claim 1, wherein Light having a wavelength or intensity corresponding to the temperature of the rear portion in the rotational direction of the front cover that is bonded to the rear portion in the rotational direction of the front cover of the front cover, and the temperature of the rear portion in the rotational direction is equal to or higher than a predetermined slip prohibition temperature. A light output member that outputs self-luminous or reflected light, and a light sensor that detects light emitted by the light output member,
10. The lock according to claim 9, wherein the temperature rise suppression means stops slip engagement of the lockup clutch when the optical sensor detects light emitted from the optical output member. Torque converter with up clutch.

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