JP2009185912A - Torque converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque converter capable of transmitting a driving force while being reduced in the deterioration of efficiency. <P>SOLUTION: The torque converter 1 includes a front cover 40 to which a driving force is inputted from a driving source, a pump shell 12 formed as the shell of a pump impeller 10 and fixed to the front cover 40 so that the driving force is transmitted thereto from the front cover 40, and a turbine shell 22 formed as the shell of a turbine runner 20 and arranged in opposition to the pump impeller 10. The converter transmits the driving force inputted to the front cover 40 from the pump impeller 10 to the turbine runner 20 using fluid as a medium. An annular member 50 is provided extending from a torus TR composed of the front cover 40 and the pump shell 12 close to the outer wall face of the turbine shell 22. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a torque converter that transmits a driving force from a driving source to a transmission side via a fluid.

  Generally, a vehicle is provided with a torque converter that transmits a driving force generated by an internal combustion engine or an electric motor as a driving source to the transmission side. This torque converter includes at least a pump impeller, a turbine runner, and a stator. The pump impeller has a pump shell as an outer shell, and a front cover is integrated through the pump shell. Therefore, the driving force from the driving source transmitted to the front cover is transmitted to the pump impeller via the pump shell. Thereby, the pump impeller rotates integrally with the front cover. In the torque converter, fluid is circulated among the pump impeller, the turbine runner, and the stator by the rotation of the pump impeller, and the turbine runner is rotated by the circulation of the fluid. The turbine runner transmits driving force to the gear group of the transmission and the like by its rotation.

  Here, the turbine runner is disposed so as to face and face the pump impeller in the axial direction of the rotating shaft. Further, a gap communicating with the gap between the pump impeller and the turbine runner is formed between the turbine shell, which is the outer shell of the turbine runner, and the pump shell. Therefore, fluid leaks into the gap between the pump shell and the turbine shell through the gap between the pump impeller and the turbine runner. The torque converter shown in Patent Document 1 reduces the flow rate of fluid leaking into the gap between the pump shell and the turbine shell by providing a protrusion at the outer peripheral end of the turbine shell.

  Some torque converters have a lock-up clutch and a damper device. The lock-up clutch is intended to improve the transmission efficiency of the driving force, and transmits the driving force from the driving source to the gear group of the transmission by engaging the piston with the front cover. On the other hand, the damper device absorbs an impact generated with the operation of the piston of the lockup clutch. In the torque converter shown in Patent Document 2, a piston in which a lock-up clutch piston and a damper device are joined by rivet joining is disclosed.

JP 2000-55168 A JP 7-83309 A

  By the way, in recent years, in order to improve the driving force transmission efficiency and reduce the size of torque converters, the ratio of the axial length to the radial length is reduced to further flatten the torque converter. It's getting on. An example of this conventional torque converter is shown in FIG. In this type of flat torque converter 100, the pump impeller 110 and the turbine runner 120 are also flat. Here, in the flat type torque converter 100 in which the flattening is further advanced, when the fluid is transferred from the pump impeller 110 to the turbine runner 120 as compared with the flattened torque converter 100 before the flattening is performed, there is no difference between them. Fluid easily leaks from the gap A to the torus chamber C through the gap M between the pump shell 112 and the turbine shell 122. That is, the fluid flowing out from the pump shell 112 is directed toward the outside of the turbine shell 122, that is, the gap M between the pump shell 112 and the turbine shell 122 as the flattening progresses. Fluid leakage to the torus chamber C through the gap M is likely to occur. Therefore, in the conventional torque converter 100, the transmission efficiency of the driving force has been reduced due to the leakage of the fluid into the torus chamber C. The torus chamber C is an internal space of the torus part TR composed of the pump impeller 110 and the front cover 140.

  Further, in this conventional torque converter 100, the turbine blade 121 is fixed to the turbine shell 122 by inserting a tab 121ao into a hole (turbine slit) 122ao formed in the turbine shell 122. A gap N shown in FIG. 6 is formed between the tab 121ao and the turbine slit 122ao for manufacturing reasons, and the fluid flowing into the turbine runner chamber B of the turbine runner 120 There is a possibility of leakage from N to the torus chamber C. Therefore, when fluid leaks from the gap N, the transmission efficiency of the driving force is further reduced.

  Further, in the torque converter shown in Patent Document 1, since the thrust force to the pump shell side is added by the rotation, the turbine shell and the projecting portion installed at the outer peripheral end portion of the turbine shell are brought into the pump shell side by the thrust force. There was a risk of deformation. And if such a deformation | transformation arises, the protrusion part may contact the pump shell. Here, as a measure for preventing such contact, an increase in the distance between the pump shell and the protrusion can be considered. However, since such measures make it easier for fluid to leak out from the gap between the pump shell and the protruding portion, Patent Documents that reduce the flow rate of fluid leaking into the gap between the pump shell and the turbine shell. The original purpose of 1 will be damaged.

  On the other hand, when the torque converter shown in Patent Document 2 is rivet-joined between the piston of the lock-up clutch and the damper device, the joint location (here, the joint portion of the piston) has to be notched. Here, in the torque converter shown in Patent Document 2, distortion or stress concentration occurs in the joint portion of the piston due to the notch, and not only the strength of the piston is reduced, but also the joint portion between the piston and the damper device. Strength will also decrease. For this reason, in the torque converter shown in Patent Document 2, it is necessary to increase the diameter of the rivet as the fitting member in order to suppress a decrease in strength of the joint portion between the piston and the damper device. Further, as another measure, it is necessary to prevent a decrease in strength by increasing the plate pressure of the piston. Therefore, in the torque converter shown in Patent Document 2, an increase in the weight of the joint portion between the piston of the lockup clutch and the damper device is caused by an increase in the diameter of the rivet. Such an increase in weight may cause a reduction in driving force transmission efficiency in the torque converter.

  Therefore, a first object of the present invention is to provide a torque converter that can improve the disadvantages of the conventional example and can suppress a decrease in driving force transmission efficiency. A second object of the present invention is to provide a torque converter that can improve the disadvantages of the conventional example and can reduce the weight of the joint between the lockup clutch and the damper device.

  In order to achieve the first object, according to the first aspect of the present invention, a front cover to which a driving force from a driving source is input and an outer shell of a pump impeller are formed and fixed to the front cover. A pump shell to which the driving force is transmitted from the front cover; and a turbine shell that forms an outer shell of the turbine runner and is disposed to face the pump impeller, and pumps the driving force input to the front cover. A torque converter that transmits a fluid as a medium from an impeller to a turbine runner includes an annular member that extends from a torus portion constituted by a front cover and a pump shell so as to be close to the outer wall surface of the turbine shell.

  In the torque converter according to claim 1, by providing an annular member close to the outer wall surface of the turbine shell from the torus portion, two of the two spaces defined by the torus portion, the turbine shell, and the annular member are provided. A space on the pump impeller side is formed as a fluid reservoir chamber. That is, in this torque converter, a gap between the pump shell and the turbine shell is included in the fluid reservoir chamber. For this reason, the fluid leaking from the gap between the pump impeller and the turbine runner flows into the fluid reservoir chamber. As a result, the leaked fluid increases the pressure in the fluid pool chamber. As a result, the fluid that has flowed out of the pump impeller is less likely to leak from the gap between the pump impeller and the turbine runner into the fluid pool chamber (the gap between the pump shell and the turbine shell), and therefore effectively flows to the turbine runner. And will be able to flow in. Therefore, the torque converter according to the first aspect can suppress a decrease in the transmission efficiency of the driving force.

  Here, as in the invention according to claim 2, it is preferable that the annular member is formed so that a surface on the extending end side facing the outer wall surface of the turbine shell is parallel to the outer wall surface.

  As a result, in the torque converter according to claim 2, since the outer wall surface and the surface on the extending end side are not parallel to each other, the sealing performance of the fluid reservoir chamber can be further improved. It becomes possible to appropriately suppress the leakage of fluid from the reservoir chamber.

  In the case where the turbine shell has at least one turbine blade mounting hole, the annular member is a pump impeller in a space defined by the torus portion, the turbine shell, and the annular member. It is preferable to dispose the turbine blade mounting hole in the side space.

  Thus, in the torque converter according to the third aspect, the gap formed between the turbine blade mounting hole and the turbine blade can be communicated with the space on the pump impeller side (that is, the fluid reservoir chamber). As a result, the fluid leaking from the gap can flow into the fluid pool chamber. Here, the leaked fluid flows into the fluid reservoir chamber together with the fluid leaking from the gap between the pump impeller and the turbine runner described above. As a result, each leaked fluid increases the pressure in the fluid pool chamber. Therefore, in the torque converter according to the third aspect, the fluid leakage from the gap between the turbine blade mounting hole and the turbine blade can be prevented, so that the reduction in driving force transmission efficiency is further suppressed. Will be able to.

  In order to achieve the second object, in the invention according to claim 4, in the torque converter according to claim 1, 2 or 3, the driving force from the driving source is obtained by engaging the piston with the front cover. Is connected to the piston by friction welding, and a damper device that absorbs an impact generated when the piston is operated in the axial direction of the rotating shaft. And a fitting member that is movably fitted in the axial direction.

  In order to achieve the second object, in the invention according to claim 5, a front cover to which a driving force from a driving source is inputted and an outer shell of a pump impeller are formed and fixed to the front cover. A pump shell to which the driving force is transmitted from the front cover, and a turbine shell that forms an outer shell of the turbine runner and is disposed to face the pump shell, and the driving force input to the front cover In a torque converter that transmits a fluid from a pump impeller to a turbine runner as a medium, a lockup clutch that transmits the driving force to the turbine runner by engaging a piston with a front cover, and an axis of the rotating shaft of the piston A damper device that absorbs the impact generated when operating in the direction and the piston is joined to the piston by friction welding On the other hand, and a, a fitting member fitted movably to the axial direction relative to the damper device.

  Here, the piston of the conventional lockup clutch, for example, had to be provided with a notch in the joint for rivet joining to the damper device, so that distortion and stress concentration were likely to occur in the part having the notch. . On the other hand, in the torque converter according to claim 4 or 5, since the piston and the damper device are joined by friction welding via the fitting member, it is not necessary to provide a notch for rivet joining in the piston. . Accordingly, in the torque converter according to claim 4 or 5, distortion and stress concentration at the joint portion of the piston can be suppressed as compared with the case of the conventional rivet joint. While being able to suppress, the strength fall of the junction location between the piston and a damper apparatus can also be suppressed. Therefore, in the torque converter according to claim 4 or 5, a reinforcing measure (for example, the joining method is a rivet joining) which has been conventionally adopted to compensate for a decrease in strength of the joining portion between the piston and the damper device. This eliminates the need for a measure to increase the rivet diameter), so that an increase in weight can be suppressed. In the torque converter according to claim 4 or 5, since friction welding is used for joining the piston and the damper device, a high-strength material can be used for the fitting member. The diameter can be reduced and the weight can be reduced. That is, in the torque converter according to the fourth or fifth aspect, it is possible to reduce the weight of the joint portion between the lockup clutch and the damper device as compared with the conventional one. In the torque converter according to claim 4 or 5, the manufacturability can be improved by reducing the diameter of the fitting member.

  Furthermore, in the conventional joining method using arc welding for joining the piston and the damper device, a bead portion accompanying the arc welding is required at the joining portion, so that a bead is formed on the joining surface between the piston and the damper device. The area of the part had to be secured. Furthermore, the conventional joining method using electron beam welding for joining the piston and the damper device requires welding work from the back side of the joint surface between the piston and the damper device, so that the workability is inferior. In addition, it takes work time and may increase the manufacturing cost. However, in the torque converter according to claim 4 or 5, since friction welding is used for joining the piston and the damper device, a bead portion is not required for arc welding, and the arc welding is used as a joining method. Compared with the conventional one used, it is possible to reduce the size of the joint between the piston and the damper device, and to increase the welding strength. In the torque converter according to claim 4 or 5, since friction welding is used for joining the piston and the damper device, the work from the back side of the joining surface at the time of electron beam welding is not required. Compared with the conventional method using beam welding as the joining method, the workability can be improved and the working time can be shortened, and the manufacturing cost can be reduced.

  The torque converter according to the present invention can suppress a decrease in transmission efficiency of the driving force transmitted from the driving source, and can reduce the weight of the joint portion between the lockup clutch and the damper device.

  Embodiments of a torque converter according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a cross-sectional view of the torque converter of the present embodiment. Reference numeral 1 in FIG. 1 indicates a torque converter of this embodiment. FIG. 2 is an enlarged view of the W portion shown in FIG. 1 of the torque converter 1 of the present embodiment. FIG. 3 is an arrow view of the torque converter 1 of this embodiment as viewed from the direction of the arrow Y shown in FIG. FIG. 4 is an enlarged view of the U portion shown in FIG. 3 of the torque converter 1 of the present embodiment. Note that the overall cross-sectional shape of the torque converter 1 of the present embodiment is obtained by rotating about the XX axis shown in FIG. Here, in this embodiment, the direction away from the XX axis is referred to as the radially outer side, and the direction approaching the XX axis is referred to as the radially inner side.

  As shown in FIG. 1, the torque converter 1 according to the present embodiment includes at least a pump impeller 10, a turbine runner 20, a stator 30, a front cover 40, an annular member 50, a lockup clutch 60, a damper device 70, and a fitting member 80. It is comprised including. In the torque converter 1, the pump impeller 10 is located on a side where a transmission gear group or the like (not shown) is installed (the left side shown in FIG. 1, hereinafter referred to as “transmission side”), and the pump impeller. 10, the turbine runner 20 is located on the side where a drive source such as an internal combustion engine (not shown) is installed (the right side shown in FIG. 1 and hereinafter referred to as “drive source side”). Here, the torque converter 1 of the present embodiment is filled with fluid such as hydraulic oil. A crankshaft (not shown) that transmits the driving force from the driving source to the torque converter 1 is on the same axis as the XX axis shown in FIG.

  First, the pump impeller 10 transmits a driving force from a driving source transmitted via a front cover 40 described later to the turbine runner 20 via a fluid flowing inside. The pump impeller 10 is composed of a plurality of pump impeller blades 11, a pump shell 12, and a pump inner core 13, and each pump impeller blade 11 is sandwiched between the pump shell 12 and the pump inner core 13. A space is formed as a fluid flow path in the impeller 10.

  The pump impeller blades 11 constituting the pump impeller 10 are formed in a curved blade shape, and a plurality of pump impeller blades 11 are arranged at substantially equal intervals in the circumferential direction around the XX axis.

  On the other hand, the pump shell 12 forms an outer shell (outer wall) of the pump impeller 10 and is formed in a ring shape centered on the XX axis. The pump shell 12 is curved so that the main part of the ring shape protrudes toward the transmission side. The pump shell 12 has an annular radially inner end 12a that protrudes radially inward from the radially inner annular end of the main portion and is fixed to the sleeve 90 by welding, An annular drive source side end portion 12b that protrudes from the annular end portion on the radially outer side of the main portion toward the drive source side and is fixed to the front cover 40 by welding is formed. That is, the pump impeller 10 is fixed to the front cover 40 via the pump shell 12. Accordingly, the pump impeller 10 rotates around the XX axis integrally with the front cover 40 to which the driving force of the driving source is transmitted. Further, the pump impeller 10 rotates together with the sleeve 90. Further, the drive source side end portion 12b protrudes closer to the drive source side than the pump impeller blade 11 in the positional relationship in the axial direction of the XX axis.

  Furthermore, the pump inner core 13 constitutes the inner wall of the pump impeller 10 and is molded into a ring shape centered on the XX axis. The pump inner core 13 is curved so that the main part of the ring shape protrudes toward the transmission side.

  Here, each pump impeller blade 11 is fixed to the curved inner wall surface of the main portion of the pump shell 12. For this reason, each pump impeller blade 11 has at least one projecting toward the inner wall surface on the end surface in the longitudinal direction facing the inner wall surface of the pump shell 12 (here, 3 as shown in FIG. 1). Tab 11a. On the other hand, a recess 12 c for fitting the tab 11 a of the pump impeller blade 11 is formed on the inner wall surface of the pump shell 12. Accordingly, each pump impeller blade 11 is fixed to the inner wall surface of the pump shell 12 by fitting the tab 11a into the recess 12c.

  Further, each pump impeller blade 11 is also fixed to the curved inner wall surface of the main portion of the pump inner core 13. For this reason, each of the pump impeller blades 11 has at least one tab 11b (in this case, two as shown in FIG. 1) protruding on the end face in the longitudinal direction facing the inner wall surface of the pump inner core 13. Form. The pump inner core 13 is formed with a hole for fitting the tab 11a of the pump impeller blade 11. Accordingly, each pump impeller blade 11 is fixed to the inner wall surface of the pump inner core 13 by fitting the tab 11b into the hole.

  That is, each pump impeller blade 11 is integrally sandwiched between the inner wall surface of the pump shell 12 and the inner wall surface of the pump inner core 13. Thereby, in the pump impeller 10, a space as a fluid flow path surrounded by the pump impeller blades 11, the pump shell 12, and the pump inner core 13 is formed inside. As the pump impeller 10 rotates, the fluid in the pump impeller 10 moves in the flow path by centrifugal force and flows out toward the turbine runner 20 as indicated by an arrow E in FIG.

  Next, the turbine runner 20 is for transmitting the driving force from the driving source to the input shaft of the transmission (not shown) via the fluid flowing in from the pump impeller 10. The turbine runner 20 includes a plurality of turbine blades 21, a turbine shell 22, and a turbine inner core 23, and the turbine runner 20 is sandwiched between the turbine shell 22 and the turbine inner core 23. A space is formed as a flow path for the fluid inside. The space is provided in such a positional relationship as to face the space of the pump impeller 10 in the axial direction of the XX axis, and is hereinafter referred to as “turbine runner chamber B”. Further, as shown in FIG. 2, the turbine runner 20 is arranged so that a gap A is formed in the axial direction of the XX axis with respect to the pump impeller blade 11 side of the pump impeller 10, and the pump shell 12 The gap M is formed in the radial direction (perpendicular to the XX axis).

  The turbine blade 21 constituting the turbine runner 20 is used to generate a rotational force around the XX axis in the turbine runner 20 when the fluid flowing into the turbine runner chamber B collides with the turbine blade 21. The blades 21 are formed in a curved blade shape, and a plurality of blades 21 are arranged at substantially equal intervals in the circumferential direction around the XX axis.

  On the other hand, the turbine shell 22 forms an outer shell (outer wall) of the turbine runner 20 and is formed into a ring shape centered on the XX axis. The turbine shell 22 is curved so that the main part of the ring shape protrudes toward the drive source. Further, the radially inner side of the turbine shell 22 is fixed to the turbine hub 93 together with a damper device 70 described later. Therefore, the turbine runner 20 and the damper device 70 rotate integrally around the XX axis. Further, since the turbine hub 93 rotates integrally with the input shaft of the transmission, the turbine runner 20 rotates the input shaft of the transmission as it rotates. That is, the turbine runner 20 transmits the driving force transmitted from the pump impeller 10 to the input shaft of the transmission.

  Further, the turbine inner core 23 forms an inner wall of the turbine runner 20 and is formed in a ring shape centering on the XX axis. The turbine inner core 23 is curved so that the main part of the ring shape protrudes toward the drive source side.

  Here, each turbine blade 21 is fixed to the curved inner wall surface of the main portion of the turbine shell 22. For this reason, each turbine blade 21 is formed with at least one tab projecting toward the inner wall surface on the end surface in the longitudinal direction facing the inner wall surface of the turbine shell 22. As shown in FIGS. 1 and 3, the turbine blade 21 of the present embodiment is formed with a radially inner tab 21ai, a radially outer tab 21ao, and an intermediate tab 21am located between them. On the other hand, a hole for attaching a tab of the turbine blade 21 (hereinafter referred to as “turbine shell slit”) is formed in the turbine shell 22. As shown in FIG. 3, the turbine shell 22 of the present embodiment includes a radially inner turbine shell corresponding to a radially inner tab 21ai, a radially outer tab 21ao and a middle tab 21am of the turbine blade 21. A slit 22ai, a radially outer turbine shell slit 22ao, and an intermediate turbine shell slit 22am are formed. Since a plurality of turbine blades 21 are fixed to the turbine shell 22, the respective turbine shell slits 22ai, 22am, 22ao are arranged at substantially equal intervals in the circumferential direction around the XX axis. A plurality of places are formed.

  In this embodiment, the radially inner tab 21ai is fitted into the radially inner turbine shell slit 22ai, and the intermediate tab 21am is fitted into the intermediate turbine shell slit 22am. Accordingly, the inner side in the radial direction is formed such that the length and width of the tab 21ai and the turbine shell slit 22ai are substantially the same. Further, the intermediate position is also formed so that the length and width of the tab 21am and the turbine shell slit 22am are substantially the same. The tabs 21ai and 21am are fitted into the turbine shell slits 22ai and 22am, and then the protruding portions are folded back toward the surfaces of the turbine shell slits 22ai and 22am.

  On the other hand, the radially outer tab 21ao is shaped to have a width substantially equal to the radially outer turbine shell slit 22ao, but is shaped so that its length is shorter than the length of the turbine shell slit 22ao. Accordingly, the radially outer tab 21ao is fitted into the radially outer turbine shell slit 22ao depending on its width, but creates a gap N shown in FIG. 4 in its length direction. This gap N is for taking into account tolerance variations in the longitudinal direction of the tabs 21ai, 21am, 21ao and the turbine shell slits 22ai, 22am, 22ao. That is, the clearance N is related to whether or not each turbine blade 21 is attached to the turbine shell 22 and improves productivity. The tab 21ao is fitted into the turbine shell slit 22ao, and then the protruding portion is folded back toward the surface of the turbine shell slit 22ao.

  Thus, each turbine blade 21 is fixed to the turbine shell 22 by fitting the tabs 21ai, 21am, 21ao into the turbine shell slits 22ai, 22am, 22ao and turning them back. That is, the turbine blade 21 is fixed to the turbine shell 22 by caulking the tabs 21ai, 21am, and 21ao to the turbine shell slits 22ai, 22am, and 22ao. The respective tabs 21ai, 21am, 21ao protrude from the outer wall surface of the turbine shell 22 after being fitted into the turbine shell slits 22ai, 22am, 22ao.

  Further, each turbine blade 21 is also fixed to the curved inner wall surface of the main portion of the turbine inner core 23. Therefore, each turbine blade 21 is provided with at least one (21 in this case, two) projecting tabs 21b on the end face in the longitudinal direction facing the inner wall surface of the turbine inner core 23, respectively. Form. The turbine inner core 23 is formed with a hole for fitting the tab 21 b of the turbine blade 21. Therefore, the tabs 21 b are fitted into the holes of the respective turbine blades 21 to be fixed to the inner wall surface of the turbine inner core 23.

  That is, each turbine blade 21 is integrally sandwiched between the inner wall surface of the turbine shell 22 and the inner wall surface of the turbine inner core 23. As a result, the turbine runner chamber B is formed in the turbine runner 20 as a fluid flow path surrounded by the turbine blades 21, the turbine shell 22, and the turbine inner core 23. The fluid flowing into the turbine runner chamber B from the pump impeller 10 collides with the wall surface of each turbine blade 21 and applies a force to the wall surface to generate a rotational force for the turbine runner 20. The fluid in the turbine runner 20 moves in the turbine runner chamber B by centrifugal force as the turbine runner 20 rotates, and flows out toward the pump impeller 10.

  Next, the stator 30 is disposed between the pump impeller 10 and the turbine runner 20 and changes the flow of fluid circulating between the pump impeller 10 and the turbine runner 20. The stator 30 includes an inner diameter portion 31, an outer diameter portion 32, and a stator blade 33.

  Here, the inner diameter portion 31 has an annular shape centered on the XX axis, and the radially inner side is fixed to the one-way clutch 34. The one-way clutch 34 is for rotating the stator 30 only in one direction around the XX axis. The one-way clutch 34 includes an outer race 34a, an inner race 34b, and a one-way clutch mechanism 34c. The outer side of the outer race 34 a is fixed to the inner diameter portion 31 of the stator 30. The inner race 34b has a radially inner side fixed to a transmission case (not shown). The one-way clutch mechanism 34c is disposed between the outer race 34a and the inner race 34b, and regulates the rotation of the outer race 34a with respect to the inner race 34b around the XX axis in one direction. The one-way clutch 34 includes a bearing 91 that allows relative rotation around the XX axis with a sleeve 90 to which the pump shell 12 is fixed, and a turbine hub 93 to which the turbine shell 22 is fixed. And a bearing 92 that enables relative rotation about the XX axis. Therefore, the stator 30 is rotatably supported with respect to the pump impeller 10 and the turbine runner 20.

  Next, the front cover 40 has a cylindrical shape whose one end is closed with the XX axis as the central axis, and when the driving force of the driving source is transmitted and the driving force is transmitted, XX It rotates around an axis. The front cover 40 protrudes toward the transmission side from the outer edge of the disc portion 40a and the disc portion 40a facing the turbine runner 20 on the drive source side, and is fixed to the pump shell 12 by welding. An annular portion 40b is formed.

  Here, an annular step is formed on the inner peripheral surface of the drive source side end portion 12b of the pump shell 12 from the protruding end surface 12bo shown in FIG. 2 toward the transmission side. That is, on the inner peripheral surface of the drive source side end 12b, the protruding end surface 12bo side is an inner wall surface having a larger diameter than the transmission side. The protruding end surface 12bo is an annular plane orthogonal to the XX axis. In addition, here, the annular plane orthogonal to the XX axis in the recessed portion forming the step is referred to as “stepped wall surface 12bh”, and the annular inner peripheral surface parallel to the XX axis in the recessed portion. This is referred to as “step inner circumferential surface 12bi”.

  On the other hand, an annular step is formed on the outer peripheral surface of the annular portion 40b of the front cover 40 from the protruding end surface 40bo shown in FIG. 2 toward the drive source side. That is, on the outer peripheral surface of the annular portion 40b, the protruding end surface 40bo side is an outer wall surface having a larger diameter than the drive source side. The protruding end surface 40bo is an annular plane orthogonal to the XX axis. In addition, here, the annular plane orthogonal to the XX axis in the recessed portion forming the step is referred to as “stepped wall surface 40bh”, and the annular inner peripheral surface parallel to the XX axis in the recessed portion. This is referred to as “step inner circumferential surface 40bi”.

  The pump shell 12 and the front cover 40 of the present embodiment are fitted to each other, and the fitting portions are welded to be integrated. In the present embodiment, the outer portion composed of the integrated pump shell 12 and the front cover 40 is referred to as a torus portion TR. Accordingly, in the torque converter 1 of the present embodiment, the pump impeller blade 11 and the turbine blade 21 are disposed in the torus portion TR. Here, a space is formed between the turbine runner 20 and the front cover 40 in the torus part TR. Hereinafter, this space is referred to as “torus chamber C”.

  The outline of the basic operation of the torque converter 1 will be described below.

  In the torque converter 1, when the driving source generates driving force, the driving force is transmitted to the front cover 40, and the front cover 40 and the pump impeller 10 are integrally rotated about the XX axis. To do. In the torque converter 1, the fluid in the pump impeller 10 flows out to the turbine runner 20 side due to the centrifugal force accompanying the rotation, and the turbine runner 20 starts rotating due to the fluid that flows in. As a result, in the torque converter 1, the fluid circulates between the pump impeller 10, the turbine runner 20, and the stator 30 in the direction of the arrow E, and is transmitted through the front cover 40 and the pump impeller 10. Force is transmitted to the turbine runner 20. The driving force transmitted to the turbine runner 20 is transmitted to the input shaft of the transmission via the turbine hub 93.

  By the way, the torque converter 1 has the highest driving force transmission efficiency by effectively flowing the fluid flowing out from the pump shell 12 into the turbine runner 20. However, since a part of the fluid flowing out from the pump shell 12 leaks into the torus chamber C through the gap M shown in FIG. 2, the transmission efficiency of the driving force deteriorates as the leak amount increases. Go. Further, in this torque converter 1, fluid leaks into the torus chamber C also from the gap N between the radially outer tab 21ao and the radially outer turbine shell slit 22ao, so that the transmission efficiency of the driving force is improved. It will fall further.

  Therefore, the torque converter 1 of the present embodiment is provided with the annular member 50 in order to reduce the amount of fluid leakage and improve the transmission efficiency of the driving force.

  The annular member 50 of this embodiment is an annular plate extending from the torus portion TR so as to be close to the annular outer wall surface of the turbine shell 22, and is prepared as a partition for the torus chamber C. In the torque converter 1 of the present embodiment, the torus chamber C is partitioned into two spaces by the annular member 50, and the fluid that leaks into one of the two spaces (the pump impeller 10 side) into the torus chamber C. It is used as a fluid reservoir chamber D to be stored. That is, the torque converter 1 of the present embodiment creates a fluid reservoir chamber D that is a small capacity space in the torus chamber C to reduce the amount of fluid leakage.

  The annular member 50 is sandwiched between the pump shell 12 and the front cover 40 constituting the torus part TR. Specifically, the annular member 50 is sandwiched between the stepped wall surface 12bh of the drive source side end portion 12b of the pump shell 12 and the protruding end surface 40bo of the annular portion 40b of the front cover 40. Therefore, in the present embodiment, the width of the step inner peripheral surface 12bi of the drive source side end portion 12b is made wider than the width of the step inner peripheral surface 40bi of the annular portion 40b, and the step of the drive source side end portion 12b. The annular member 50 is sandwiched between the wall surface 12bh and the protruding end surface 40bo of the annular portion 40b.

  Thus, in the torque converter 1 of this embodiment, the fluid reservoir chamber D is created by the annular member 50, and the fluid leaking into the torus chamber C is retained in the fluid reservoir chamber D. That is, the fluid leaking into the torus chamber C through the gap M flows into the fluid reservoir chamber D. When the fluid reservoir chamber D is filled with the fluid, further inflow of the fluid that is about to leak from the gap A to the gap M is suppressed to the fluid reservoir chamber D. Therefore, in the torque converter 1, the fluid flowing out from the pump impeller 10 is effectively guided to the turbine runner 20, and the transmission efficiency of the driving force can be improved.

  Here, the annular member 50 is preferably disposed so that all the turbine shell slits 22ai, 22am, and 22ao are disposed in the fluid reservoir chamber D. In the present embodiment, only the radially outer turbine shell slit 22ai is included in the fluid reservoir chamber D due to the arrangement of other components such as the damper device 70. That is, the fluid reservoir chamber D of the present embodiment communicates with the gap N described above. Therefore, in the torque converter 1 of the present embodiment, the fluid leaked into the torus chamber C through the gap N flows into the fluid reservoir chamber D. When the fluid reservoir chamber D is filled with the fluid, further inflow of the fluid that is about to leak from the gap N into the fluid reservoir chamber D is suppressed. For this reason, in the torque converter 1, the fluid flowing into the turbine runner 20 is less likely to leak, and the fluid can be effectively used as a driving force for the rotation of the turbine runner 20. The transmission efficiency can be further improved.

  In the present embodiment, since the annular member 50 is close to the outer wall surface of the turbine shell 22, the sealing property of the fluid reservoir chamber D is improved, and the fluid in the fluid reservoir chamber D is transferred to the other side of the torus chamber C. Leakage into the space can be suppressed. Therefore, in the torque converter 1 of the present embodiment, the fluid full state in the fluid reservoir chamber D can be maintained, and therefore it is possible to appropriately prevent fluid leakage through the gap M and the gap N. Thus, the transmission efficiency of the driving force can be improved more effectively.

  Here, the annular member 50 preferably forms an annular end surface (annular member end surface) 50a facing the outer wall surface of the turbine shell 22 in parallel with the outer wall surface. As a result, the hermeticity of the fluid reservoir chamber D can be further improved. Therefore, in the torque converter 1 of this embodiment, the fluid leakage through the gap M and the gap N is prevented and the transmission efficiency of the driving force is further improved. be able to.

  Further, in the torque converter 1 of the present embodiment, the annular member 50 is installed separately from the turbine shell 22, so even if a thrust force is generated in the turbine shell 22 due to rotation, the turbine shell 22 and the pump Contact with the shell 12 can be suppressed. Therefore, in the torque converter 1, it is possible to dispose the turbine shell 22 and the pump impeller 10 close to each other, and it is possible to further suppress a decrease in driving force transmission efficiency.

  The annular member 50 may be integrally formed with the pump shell 12 or the front cover 40. Thereby, in this torque converter 1, the man-hour which pinches | interposes the annular member 50 between the pump shell 12 and the front cover 40 can be reduced. Therefore, the torque converter 1 in this case can improve productivity and reduce cost.

  Next, the lockup clutch 60 will be described. The lock-up clutch 60 is composed of a piston 61 and a friction plate 62, and by engaging with the front cover 40, the driving force of the drive source transmitted to the front cover 40 is transmitted to the input shaft of the transmission. To communicate directly to

  The piston 61 is a ring-shaped member that rotates about the XX axis as a central axis, and is disposed between the turbine runner 20 and the front cover 40 in the axial direction of the XX axis.

  The radially outer end 61a of the piston 61 is shaped such that the surface of the front cover 40 facing the disc portion 40a is a plane orthogonal to the axial direction of the XX axis. The friction plate 62 is a plate-shaped member formed in an annular shape with a material having a high friction coefficient, and is attached to the plane of the end portion 61 a on the radially outer side of the piston 61.

  An end 61b on the radially inner side of the piston 61 is supported on a sliding surface 93a parallel to the axial direction of the XX axis on the outer wall surface of the turbine hub 93 so as to reciprocate in the axial direction of the XX axis. Yes. The piston 61 is attached so as to rotate integrally with the turbine hub 93. Therefore, the piston 61 moves toward the disc portion 40a of the front cover 40, and the friction plate 62 comes into contact with the disc portion 40a and is locked by the frictional force. The piston 61 rotates integrally with the front cover 40 when the piston 61 is locked to the front cover 40. That is, the driving force of the driving source transmitted to the front cover 40 is transmitted to the piston 61 via the friction plate 62. On the other hand, if the piston 61 is not locked to the front cover 40, the piston 61 rotates relative to the front cover 40.

  Further, since the turbine runner 20 is fixed to the turbine hub 93, the turbine runner 20 rotates integrally with the piston 61. Therefore, when the piston 61 is locked to the front cover 40, the turbine runner 20 rotates integrally with the pump impeller 10, the front cover 40, the lockup clutch 60, and the like. That is, at that time, the driving force from the driving source is transmitted to the input shaft of the transmission without generating a driving loss due to the operation of the torque converter 1.

  Next, the damper device 70 absorbs an impact generated when the friction plate 62 of the lock-up clutch 60 comes into contact with the front cover 40 or when the engagement state between the friction plate 62 and the front cover 40 is released. It is a device. That is, the damper device 70 absorbs an impact generated in the lockup clutch 60 when the piston 61 of the lockup clutch 60 is operated. The damper device 70 includes a first plate 71, a second plate 72, and a plurality of elastic members 73.

  The first plate 71 is a ring-shaped plate (transmission-side plate 71a, drive-source-side plate 71b) centered on a pair of XX axes opposed to each other with an interval in the axial direction of the XX axis. The second plate 72 and the plurality of elastic members 73 are sandwiched between the transmission-side plate 71a and the drive-source-side plate 71b. The radially inner end of the transmission-side plate 71 a is fixed to the turbine hub 93 by a fixing member 94 such as a rivet together with the turbine shell 22 of the turbine runner 20. Therefore, the first plate 71 rotates integrally with the turbine runner 20 and the piston 61 of the lockup clutch 60.

  The second plate 72 is a ring-shaped plate with the XX axis as the central axis, and the outermost diameter thereof is formed larger than the outermost diameter of the first plate 71. The radially outer end 72a of the second plate 72 is connected to the springs of the plates 71a and 71b at the radially outer ends of the transmission plate 71a and the drive source plate 71b. It is pinched by force. Further, the radially inner end 72b of the second plate 72 is also sandwiched between the transmission-side plate 71a and the drive-source-side plate 71b.

  Here, the second plate 72 is fixed to the piston 61 of the lockup clutch 60 via a plurality of fitting members 80. The fitting member 80 is molded using at least a high-strength material that can withstand high-speed rotation and pressure, and a plurality of fitting members 80 are arranged in the circumferential direction around the XX axis.

  Here, one end of a columnar or cylindrical (columnar or cylindrical in this embodiment) fitting member 80 is joined to the piston 61 by friction welding, and the joined fitting member 80 is joined to the second plate 72. Is fitted to the notch so as to be movable in the axial direction (axial direction of the rotation axis of the piston 61). That is, the piston 61 and the second plate 72 can move relative to each other in the axial direction with the plurality of fitting members 80 serving as guide members. The friction welding means that the fitting member is rotated at a high speed and slid onto the object to be joined (here, the flat surface 61c of the piston 61), and the fitting member is softened by the frictional heat generated at the same time, and the fitting is performed. In this joining method, pressure is applied to members to be joined to join them.

  By applying friction welding to the fitting member 80, a joining surface 80 a shown in FIG. 5 that is substantially parallel to the flat surface 61 c of the piston 61 is formed at the end portion on the piston 61 side. The flat surface 61c and the bonding surface 80a are parallel to a plane orthogonal to the XX axis. The size of the flat surface 61c of the piston 61 is set in consideration of the annular pressure contact allowance d1 shown in FIG. 5 that can be formed in the fitting member 80 after friction welding. That is, the size of the flat surface 61c is set to be larger than at least the sum of the diameter d2 of the fitting member 80 and the pressure contact allowance d1 × 2. It should be noted that the size of the flat surface 61c is not necessarily larger than the sum of the diameter d2 of the fitting member 80 and the pressure contact allowance d1 × 2, and is equal to or smaller than the sum. Also good. In this embodiment, the joint surface 80a of the fitting member 80 is rotated at a high speed and slid onto the flat surface 61c of the piston 61, and a pressure pressing the fitting member 80 against the flat surface 61c is applied to perform friction welding. Do.

  As described above, in this embodiment, friction welding is used for joining the lockup clutch 60 and the damper device 70, so that the following effects can be obtained.

  First, in the case of conventional rivet joining, a notch is required at a location corresponding to the flat surface 61c of the piston 61. However, when using friction welding, such a notch is not necessary. For this reason, in the torque converter 1 of the present embodiment, it is possible to suppress the strength reduction of the piston 61 due to the notch, and to suppress the generation of distortion of the piston 61 due to the notch formation and the stress concentration due to the notch. Can do. Therefore, in this torque converter 1, the strength of the joint portion can be ensured without taking measures for reinforcement such as increasing the rivet diameter and increasing the thickness of the piston 61 and the like as in the prior art. Further, in the torque converter 1, such a reinforcing measure is not necessary, so that the joint portion between the lockup clutch 60 and the damper device 70 can be reduced in size and weight. And since the weight reduction makes it possible to suppress the loss of force received from the fluid for rotating the turbine runner 20 connected to the damper device 70, the torque converter 1 reduces the transmission efficiency of the driving force. Can be suppressed.

  Furthermore, since this torque converter 1 can use a high-strength material for the fitting member 80, the fitting member 80 can have a smaller diameter than the conventional rivet. Can be further reduced in size and weight, and further, further reduced in size and weight at the joint between the lock-up clutch 60 and the damper device 70 can be achieved. Moreover, since this torque converter 1 can make the fitting member 80 small, manufacturability is good and it can suppress the increase in processing cost. In addition, the torque converter 1 can reduce the inertia added to the fitting member 80 as it rotates by reducing the weight of the fitting member 80.

  Furthermore, in the torque converter 1, when the piston 61 of the lockup clutch 60 is engaged with the front cover 40, a load is applied to the fitting member 80. The fitting member 80 is molded from a high-strength material. Thus, deformation and breakage of the fitting member 80 at that time can be avoided. Therefore, this torque converter 1 can improve durability and reliability as compared with the conventional rivet joining.

  In addition, when arc welding is used to join the lockup clutch 60 and the damper device 70, a bead portion is formed at the joint portion. Therefore, the flat surface 61c of the piston 61 is also taken into consideration of the width of the bead portion. Although the size must be determined, in the torque converter 1, the pressure contact allowance d1 described above is smaller than the width of the bead portion, so that the flat surface 61c, that is, the joining portion can be reduced in size. Moreover, since this torque converter 1 uses friction welding, the strength of the joint portion is higher than that of arc welding.

  Further, when electron beam welding is used to join the lock-up clutch 60 and the damper device 70, it is necessary to perform welding work from the front cover 40 side of the piston 61, which requires work time and increases the manufacturing cost. In the torque converter 1, by using friction welding, the working time can be shortened and the manufacturing cost can be reduced.

  Here, a plurality of elastic members 73 are connected to the second plate 72. A plurality of elastic members 73 are provided in the circumferential direction around the XX axis, and can be expanded and contracted in the rotational direction around the XX axis and the axial direction of the XX axis. Shock absorbing spring. When the friction plate 62 of the lock-up clutch 60 comes into contact with the front cover 40 or when the friction plate 62 and the front cover 40 are released from the locked state, the rotational direction around the XX axis and the XX An impact due to the force applied in the axial direction of the shaft is generated in the lockup clutch 60. The elastic member 73 absorbs the impact generated at that time and prevents the impact from being transmitted to the turbine runner 20 via the piston 61 and the turbine hub 93. Accordingly, in the torque converter 1, the operation of the lockup clutch 60 is smoothly performed by the damper device 70.

  As described above, in the torque converter 1 of this embodiment, the annular member 50 is extended from the torus portion TR so as to be close to the outer wall surface of the turbine shell 22, and the fluid reservoir chamber D is formed in the torus chamber C. Therefore, the leakage of the fluid that has flowed out of the pump impeller 10 and the fluid in the turbine runner chamber B can be prevented, and a reduction in the transmission efficiency of the driving force can be suppressed.

  Further, since the torque converter 1 of the present embodiment uses friction welding for joining the lock-up clutch 60 and the damper device 70, it is possible to improve the strength of the joint, reduce the size and weight, and The workability of the joining, that is, the manufacturability can be improved. Furthermore, since the torque converter 1 can be reduced in weight at the joint portion, it is possible to suppress a decrease in transmission efficiency of the driving force.

  As described above, the torque converter according to the present invention is useful as a technique capable of improving the transmission efficiency of the driving force and reducing the weight of the joint portion between the lockup clutch and the damper device.

It is sectional drawing shown about the structure of the torque converter which concerns on this invention. It is an enlarged view of the W section shown in FIG. FIG. 2 is an arrow view of the turbine runner as seen from the direction of arrow Y shown in FIG. 1. FIG. 4 is an enlarged view of a U portion shown in FIG. 3. It is an enlarged view of the V section shown in FIG. It is a figure explaining the conventional torque converter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Torque converter 10 Pump impeller 11 Pump impeller blade 12 Pump shell 13 Pump inner core 20 Turbine runner 21 Turbine blade 21ao Radial outside tab 22 Turbine shell 22ao Radial outside turbine shell slit 23 Turbine inner core 30 Stator 40 Front cover 50 Annular member 50a Annular member end surface 60 Lock-up clutch 61 Piston 62 Friction plate 70 Damper device 71 First plate 71a Transmission side plate 71b Drive source side plate 72 Second plate 73 Elastic member 80 Fitting member C Torus chamber D Fluid Pool room TR torus club

Claims (5)

A front cover to which a driving force from a driving source is input, an outer shell of a pump impeller, a pump shell to which the driving force is transmitted from the front cover by being fixed to the front cover, and a turbine runner A turbine shell that forms an outer shell and is disposed to face the pump impeller, and transmits the driving force input to the front cover from the pump impeller to the turbine runner as a medium. In the converter,
A torque converter, comprising: an annular member extending from a torus portion constituted by the front cover and the pump shell so as to be close to an outer wall surface of the turbine shell.   The torque converter according to claim 1, wherein the annular member is formed such that a surface on the extending end side facing the outer wall surface of the turbine shell is parallel to the outer wall surface. The turbine shell has at least one hole for mounting a turbine blade;
The annular member is disposed so that the hole for attaching the turbine blade is disposed in a space on the pump impeller side in a space defined by the torus portion, the turbine shell, and the annular member. The torque converter according to claim 1 or 2, characterized by the above. A lock-up clutch that transmits a driving force from the driving source to the turbine runner by engaging a piston with the front cover;
A damper device that absorbs an impact generated when the piston is operated in the axial direction of the rotation shaft;
A fitting member which is joined to the piston by friction welding, and is fitted to the damper device so as to be movable in the axial direction;
The torque converter according to claim 1, further comprising: A front cover to which a driving force from a driving source is input, an outer shell of a pump impeller, a pump shell to which the driving force is transmitted from the front cover by being fixed to the front cover, and a turbine runner A turbine shell that forms an outer shell and is disposed to face the pump shell, and transmits the driving force input to the front cover from the pump impeller to the turbine runner as a medium. In the converter,
A lock-up clutch that transmits the driving force to the turbine runner by engaging a piston with the front cover;
A damper device that absorbs an impact generated when the piston is operated in the axial direction of the rotation shaft;
A fitting member which is joined to the piston by friction welding, and is fitted to the damper device so as to be movable in the axial direction;
A torque converter characterized by comprising:

Images