JP2006022918A - Front cover and hydraulic torque transmitting device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in fastening a bolt caused by accumulation of dust such as chips in a screw hole, with respect to a front cover having a recessed part on a part corresponding to a fastening member. <P>SOLUTION: The torque is transmitted to this front cover 2 from an engine in a torque converter 1, and the front cover 2 comprises a disc-shaped main body 57 and a nut 44. The nut 44 is fixed to an axial engine side of an outer peripheral part of the disc-shaped main body 57 by welding. A flexible plate 42 is fastened to the nut 44. The disc-shaped main body 57 has the recessed part 58 recessed in the axial direction at a position corresponding to the nut 44. A second side face 44b of the nut 44 has a groove 63 for communicating the recessed part 58 with the external. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a front cover and a fluid torque transmission device, and more particularly to a front cover in which a fastening member is fixed by welding and a fluid torque transmission device using the same.

  The torque converter is a device that transmits torque from the engine to the transmission side via an internal working fluid. The torque converter mainly includes a front cover to which torque from the engine is input, and a fluid chamber fixed to the transmission side of the front cover. , An impeller disposed opposite to the engine side of the impeller and outputting torque to the transmission side, an operation disposed between the inner peripheral portion of the impeller and the inner peripheral portion of the turbine, and the operation from the turbine toward the impeller And a stator that rectifies the flow of fluid.

  The lockup device is disposed in a space between the turbine and the front cover, and is a device for directly transmitting torque from the front cover to the turbine by mechanically connecting the front cover and the turbine. The lockup device includes, for example, a disk-like piston that is connected by being pressed against the friction surface of the front cover, and an elastic connection mechanism that transmits torque between the piston and the turbine.

In such a fluid torque transmission device, the front cover functions as an input side member to which torque from the engine is input. Therefore, a fastening mechanism for fastening the engine-side plate is provided on the axial engine side surface of the outer peripheral portion of the front cover. The fastening mechanism is a combination of bolts and nuts, and one member is fixed to the front cover by welding. By this fastening mechanism, the outer peripheral portion of the plate which is a member on the engine side is fixed to the front cover. In addition, the inner peripheral part of the plate is fixed to the tip of the crankshaft by a bolt (for example, see Patent Document 1).
JP 2003-106403 A

When the nut is fixed to the front cover as a fastening member, a recess (a counterbore) recessed in the axial direction from the other part is formed at a position corresponding to the screw hole of the nut on the side surface of the engine in the axial direction of the front cover. ing. This is to prevent the front end of the bolt from interfering with the front cover.
However, with such a structure, chips may enter the recess during the end face processing of the nut. Since the recess has a larger diameter than the screw hole of the nut, the chips accumulate on the outer periphery of the recess. For this reason, even if air is blown from the screw hole, the chips are difficult to go out. In particular, when a convex portion is formed around the screw hole of the nut, the outer peripheral portion of the concave portion has a bag path shape, so that the chips are more difficult to go out. And if this chip | tip moves with the vibration in conveyance, for example, and it adheres to the screw hole of a nut, a malfunction will arise at the time of bolt fastening.

  The subject of this invention is reducing the malfunction at the time of the bolt fastening by refuse, such as a chip, in the front cover which provided the recessed part corresponding to the fastening member.

  According to a first aspect of the present invention, a torque is transmitted from the engine in the fluid torque transmission device, and includes a plate-like main body and a nut. The plate-like main body constitutes a part of the fluid chamber. The nut is fixed to the axial engine side of the outer peripheral portion of the plate-shaped main body by welding. A member on the engine side is fastened to the nut. The plate-like main body is formed with a recess recessed in the axial direction at a position corresponding to the nut. On the surface of the nut that comes into contact with the plate-like main body, a groove is formed to communicate the recess with the outside.

For example, when a nut is processed, chips may be generated and enter the recess. However, in this front cover, since the groove is formed in the nut, the chips accumulated in the recess are easily discharged to the outside through the groove. Therefore, the chips collected in the recesses are difficult to adhere to the nut.
According to a second aspect of the present invention, in the front cover according to the first aspect, a convex portion extending into the concave portion is formed on the surface of the nut that contacts the plate-like main body, and the groove is formed around the convex portion.

In this front cover, although the convex part is formed in the nut, the chips existing around the convex part are easily discharged to the outside through the groove.
According to a third aspect of the present invention, in the front cover according to the first or second aspect, a part of the outer periphery of the nut is welded, and the groove has an opening in a portion that is not welded on the outer periphery of the nut. .

In this front cover, the chips in the recess are discharged to the outside from the opening of the groove.
In the front cover according to a fourth aspect, in the third aspect, the nut is welded on both sides in the rotational direction and is not welded on both sides in the radial direction. The groove has openings on both sides of the nut in the radial direction.
According to a fifth aspect of the present invention, in the fluid type torque transmission device, torque from the engine is transmitted, and includes a plate-shaped main body and a nut. The plate-like main body constitutes a part of the fluid chamber. The nut is fixed to the axial engine side of the outer peripheral portion of the plate-shaped main body by welding. A member on the engine side is fastened to the nut. The plate-like main body is formed with a recess recessed in the axial direction at a position corresponding to the nut. On the surface of the plate-shaped main body that comes into contact with the nut, a groove that communicates the recess with the outside is formed.

For example, when a nut is processed, chips may be generated and enter the recess. However, in this front cover, since the groove is formed in the front cover, the chips accumulated in the recess are easily discharged to the outside through the groove. Therefore, the chips collected in the recesses are difficult to adhere to the nut.
According to a sixth aspect of the present invention, in the front cover according to the fifth aspect, the surface of the nut that contacts the plate-like main body is formed with a convex portion extending into the concave portion, and the groove is formed around the convex portion.

In this front cover, although the convex part is formed in the nut, the chips existing around the convex part are easily discharged to the outside through the groove.
The front cover according to claim 7 is the front cover according to claim 5 or 6, wherein a part of the outer periphery of the nut is welded, and the groove has an opening in a portion that is not welded on the outer periphery of the nut. .

In this front cover, the chips in the recess are discharged to the outside from the opening of the groove.
In the front cover according to an eighth aspect, in the seventh aspect, the nut is welded on both sides in the rotational direction and is not welded on both sides in the radial direction. The groove has openings on both sides of the nut in the radial direction.
According to a ninth aspect of the present invention, there is provided a fluid type torque transmitting device according to any one of the first to eighth aspects, an impeller fixed to the front cover to form a fluid chamber, and facing the impeller in the fluid chamber. And a disposed turbine.

  In the present invention, in the front cover in which the concave portion is provided in the portion corresponding to the nut, the trouble at the time of bolt fastening due to dust such as chips collecting in the screw hole is reduced.

1. Structure of Torque Converter Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a torque converter 1 as an embodiment of the present invention. The torque converter 1 is employed in a vehicle. 1 is the rotation axis of the torque converter 1.
In FIG. 1, the torque converter 1 forms a hydraulic oil chamber by a front cover 2 and an impeller shell 9 fixed to an outer peripheral side protruding portion 8 of the front cover 2. The front cover 2 can be attached to the crankshaft 41 of the engine by each component, and torque from the engine is input. A plurality of impeller blades 10 are fixed inside the impeller shell 9 (described later). An impeller 3 is constituted by the impeller shell 9 and the impeller blade 10. A turbine 4 is disposed at a position facing the impeller 3 in the hydraulic oil chamber. The turbine 4 includes a turbine shell 11 and a plurality of turbine blades 12 fixed on the turbine shell 11. An inner peripheral end of the turbine shell 11 is fixed to a flange 15 of the turbine hub 13 via a rivet 14. The turbine hub 13 has a spline groove 20 that engages with a main drive shaft (not shown) of the transmission on the inner periphery. A stator 5 is disposed between the inner periphery of the impeller 3 and the inner periphery of the turbine 4. The stator 5 adjusts the direction of hydraulic fluid returned from the turbine 4 to the impeller 3 and is supported by a fixed shaft (not shown) via a one-way clutch 6.

2. Structure of Lock-Up Clutch The lock-up clutch 7 is a device that is disposed in a space between the front cover 2 and the turbine 4 and mechanically connects the front cover 2 and the turbine 4. The lockup clutch 7 mainly includes a piston 22 and an elastic coupling mechanism 40 for elastically coupling the piston 22 to the turbine 4.

  The piston 22 is a disk-shaped member, and divides the space between the front cover 2 and the turbine shell 11 into a first hydraulic chamber 36 on the front cover 2 side and a second hydraulic chamber 37 on the turbine 4 side. Are arranged as follows. The piston 22 is made of a thin metal plate. The piston 22 has an inner peripheral cylindrical portion 23 extending toward the transmission side on the inner peripheral side. The inner peripheral cylindrical portion 23 is supported on the outer peripheral surface 19 of the cylindrical portion 16 of the flange 15 of the turbine hub 13 so as to be relatively movable in the axial direction and the circumferential direction. That is, the inner peripheral surface 25 of the inner peripheral cylindrical portion 23 is in contact with the outer peripheral surface 19 of the cylindrical portion 16. An annular groove is formed on the outer peripheral surface 19 of the cylindrical portion 16 at an intermediate position in the radial direction. A seal ring 18 is disposed in the annular groove, and the seal ring 18 is in contact with the inner peripheral surface 25 of the inner peripheral protrusion 23. Thus, the seal ring 18 seals the inner peripheral portions of the first hydraulic chamber 36 and the second hydraulic chamber 37.

  An outer peripheral cylindrical portion 24 extending to the transmission side is formed on the outer peripheral portion of the piston 22. An annular friction facing 35 is stretched on the engine side in the outer peripheral portion of the piston 22. The friction facing 35 is opposed to an annular flat friction surface 2 a formed on the inner periphery of the front cover 2. By the engagement between the friction facing 35 and the front cover friction surface 2a, the outer peripheral portions of the first hydraulic chamber 36 and the second hydraulic chamber 37 are sealed.

  The elastic coupling mechanism 40 is disposed between the piston 22 and the turbine 4, more specifically, between the outer peripheral portion of the piston 22 and the outer peripheral portion of the turbine shell 11. The elastic coupling mechanism 40 includes a retaining plate 27 as a drive side member, a driven plate 33 as a driven side member, and a plurality of coil springs 32 disposed between the plates 27 and 33. The retaining plate 27 is an annular plate member disposed on the outer peripheral side of the piston 22, that is, on the inner peripheral side of the outer peripheral side tubular part 24. The inner peripheral portion of the retaining plate 27 is fixed to the piston 22 by a plurality of rivets (not shown). The retaining plate 27 is a member for holding the coil spring 32 and for transmitting torque by engaging with both sides of the coil spring 32 in the circumferential direction. The retaining plate 27 has holding portions 28 and 29 that respectively support the outer peripheral side and the inner peripheral side of the plurality of coil springs 32 arranged in the circumferential direction. The inner peripheral holding portion 29 is formed by being cut and raised from the disc-shaped portion of the retaining plate 27. Further, the retaining plate 27 has engaging portions 30 for supporting both sides of each coil spring 32 in the circumferential direction. The driven plate 33 is an annular plate member fixed to the rear surface of the outer peripheral portion of the turbine shell 11. The driven plate 33 is formed with a plurality of claw portions 34 extending to the engine side at a plurality of locations in the circumferential direction. The claw portions 34 are engaged with both ends of each coil spring 32 in the circumferential direction. As a result, torque from the retaining plate 27 is transmitted to the driven plate 33 via the coil spring 32.

3. Next, a structure for inputting torque from the crankshaft 41 to the torque converter 1 will be described. This structure is a fastening structure 43 for fastening the outer peripheral part of the flexible plate 42 to the outer peripheral part of the front cover 2, and is mainly composed of a combination of a plurality of nuts 44 and bolts 45. The outer periphery of the front cover 2 has a substantially flat plate-like main body 57, and the fastening structure 43 is provided on the plate-like main body 57.

  The flexible plate 42 is a thin plate-like member, and has high rigidity in the rotation direction, but has low rigidity in the axial direction and the bending direction. The inner peripheral portion of the flexible plate 42 is fixed to the tip of the crankshaft 41 by a plurality of bolts 43. The outer peripheral portion of the flexible plate 42 is fixed to the outer peripheral portion of the front cover 2 by a fastening structure 43.

  2 to 4, the nut 44 is a block-like member in which a screw hole 61 extending in the axial direction is formed, and includes a first side surface 44 a on the axial engine side and a second side surface on the axial transmission side. 44b. The nut 44 is fixed to the axial engine side surface 57 a of the plate-like main body 57 of the front cover 2 by welded portions 49 and 50. As shown in FIG. 4, the welded portions 49 and 50 are provided on both sides of the nut 44 in the rotational direction. The welded portions 49 and 50 partially wrap around both sides of the nut 44 in the radial direction, but are not formed on most of both sides of the nut 44 in the radial direction. As a result, the second side surface 44 b of the nut 44 is in contact with the axial engine side surface 57 a of the plate-like main body 57 of the front cover 2.

The bolt 45 is provided corresponding to the nut 44, and includes a head portion 45a and a screw portion 45b. The screw portion 45 b passes through the hole 42 a of the plate 42 and is further screwed into the screw hole 61 of the nut 44. As a result, the plate 42 is sandwiched between the head portion 45a of the bolt 45 and the nut 44 (specifically, the first side surface 44a).
A concave portion 58 that is recessed in the axial direction is formed at a position corresponding to the screw hole 61 of the nut 44 in the plate-like main body 57 of the front cover 2. The concave portion 58 is a relief portion for preventing the tip of the screw portion 45 b of the bolt 45 from interfering with the front cover 2. The center of the recess 58 coincides with the screw hole 61 but has a larger outer diameter. Therefore, the recess 58 further extends to the outer peripheral side of the screw hole 61.

  The nut 44 has a convex portion 62 extending from the periphery of the screw hole 61 toward the axial transmission side on the second side surface 44b. The convex portion 62 is required in relation to the length of the screw portion 45b of the bolt 45. The convex part 62 enters the concave part 58. Further, the tip of the screw portion 45 b of the bolt 45 extends to the tip of the convex portion 62 and enters the concave portion 58.

  A groove 63 is formed around the convex portion 62 on the second side surface 44 b of the nut 44. That is, a space is secured between the bottom surface of the groove 63 and the axial engine side surface 57 a of the plate-like main body 57 of the front cover 2. The groove 63 allows the outer peripheral portion of the recess 58 to communicate with the space outside thereof. More specifically, as shown in FIG. 4, the groove 63 is formed around the screw hole 61 and the convex portion 62 and further extends on both sides in the radial direction. In other words, the groove 63 is composed of an annular portion 63a around the convex portion 62 and two connecting portions 63b extending in the radial direction therefrom. In addition, the welding part is not provided in the part corresponding to the connection part 63b of the groove | channel 63, but it is the opening parts 51 and 52, respectively.

4). Advantages of the Present Invention The front cover 2 transmits torque from the engine in the torque converter 1 and includes a nut 44 fixed to the plate-like main body 57. The nut 44 is fixed to the axial engine side surface 57 a of the plate-like main body 57 by welds 49 and 50. A flexible plate 42 is fastened to the nut 44 by a bolt 45. The plate-like main body 57 of the front cover 2 is formed with a concave portion 58 that is recessed in the axial direction at a position corresponding to the nut 44. The second side surface 44 b of the nut 44 is formed with a recess 58 and a groove 63 that communicates with the outside.

  For example, it is assumed that the first side surface 44a of the nut 44 is cut in order to accurately realize the axial dimension of the torque converter 1 under tight tolerances. In that case, chips may enter the recess 58 from the screw hole 61. Conventionally, in such a case, it has been difficult to discharge the chips from the recess 58. However, since the groove 63 is formed in the nut 44 in the front cover 2, when air is blown from the screw hole 61 of the nut 44, the chips accumulated in the recess 58 pass through the groove 63 and the opening 50. , 51 are discharged to the outside. Therefore, the chips collected in the recess 58 are unlikely to adhere to the screw hole 61 of the nut 44.

5. Other Embodiments Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments and can be changed without departing from the scope of the invention. For example, the shape of the groove provided in the fastening member is not limited to the above embodiment.
Further, as shown in FIG. 5, a groove 57 b may be formed on the axial engine side surface 57 a of the plate-like main body 57 of the front cover 2. The groove 57b has the same shape as the groove 63 and has the same function. That is, in this embodiment, the same effect as that of the above embodiment can be obtained.

  In the above embodiment, the present invention is applied to the torque converter, but may be applied to other fluid type torque transmission devices.

1 is a schematic vertical sectional view of a torque converter in which an embodiment of the present invention is employed. The longitudinal cross-sectional schematic of the fastening structure which consists of a nut and a volt | bolt. The longitudinal cross-sectional schematic of the fastening structure of the state which removed the volt | bolt. The partial top view of a fastening structure. The longitudinal cross-sectional schematic of the fastening structure which consists of a nut and a volt | bolt in other embodiment.

Explanation of symbols

1 Torque converter (fluid torque transmission device)
2 Front cover 2a Friction surface 3 Impeller 4 Turbine 42 Flexible plate 44 Nut 45 Bolt 57 Plate body 58 Recess 61 Screw hole 62 Protrusion 63 Groove

Claims (9)

A front cover to which torque from an engine is transmitted in a fluid torque transmission device,
A plate-like body constituting a part of the fluid chamber;
A nut that is fixed by welding to the axial engine side of the outer peripheral portion of the plate-like main body, and the engine-side member is fastened;
The plate-like main body is formed with a recess recessed in the axial direction at a position corresponding to the nut,
On the surface of the nut that comes into contact with the plate-like main body, a groove is formed that communicates the recess with the outside.
front cover.   The front cover according to claim 1, wherein a convex portion extending into the concave portion is formed on a surface of the nut that contacts the plate-like main body, and the groove is formed around the convex portion.   The front cover according to claim 1 or 2, wherein a part of the outer periphery of the nut is welded, and the groove has an opening in a portion that is not welded on the outer periphery of the nut. The nut is welded on both sides in the rotational direction and not welded on both sides in the radial direction,
The front cover according to claim 3, wherein the groove has openings on both radial sides of the nut. A front cover to which torque from an engine is transmitted in a fluid torque transmission device,
A plate-like body constituting a part of the fluid chamber;
A nut that is fixed by welding to the axial engine side of the outer peripheral portion of the plate-like main body, and the engine-side member is fastened;
The plate-like main body is formed with a recess recessed in the axial direction at a position corresponding to the nut,
On the surface of the plate-like body that contacts the nut, a groove is formed that communicates the recess with the outside.
front cover.   The front cover according to claim 5, wherein a convex portion extending into the concave portion is formed on a surface of the nut that contacts the plate-like main body, and the groove is formed around the convex portion.   The front cover according to claim 5 or 6, wherein a part of an outer periphery of the nut is welded, and the groove has an opening in a portion that is not welded on the outer periphery of the nut. The nut is welded on both sides in the rotational direction and not welded on both sides in the radial direction,
The front cover according to claim 7, wherein the groove has openings on both radial sides of the nut. The front cover according to any one of claims 1 to 8,
An impeller fixed to the front cover to form a fluid chamber;
A turbine disposed opposite the impeller in the fluid chamber;
A fluid-type torque transmission device.

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