JP2003278879A - Drive plate fastening structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a strength of a drive plate by improving a fastening structure to a torque converter case of a drive plate which rotates in synchronization with an engine. <P>SOLUTION: A boss part 32 where a female screw 33 in which a bolt is screwed from a torque converter side is formed integral with a part of an annular ring member 31. A wall thickness B of a thin part in the outer peripheral side of the female screw 33 in the boss part 32 is equal to a wall thickness Aa of a part other than the boss part 32. The inner peripheral surface of a part other than the boss part 32 is formed on a taper surface inclined so as to increase the wall thickness toward the outside (the engine side) (Ab>Aa). By so doing, the stress concentration on the thin part of the boss part 32 is prevented, and the axial warpage of the ring member 31 is suppressed, which leads to securement of strength. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fastening a drive plate to a torque converter case.

[0002]

2. Description of the Related Art In a vehicle equipped with an automatic transmission with a torque converter, the crankshaft (output shaft) of the engine and the automatic transmission are connected via a torque converter of the automatic transmission (Japanese Patent Laid-Open No. 5-21853). (See Japanese Patent No. 111215). First, before assembling the transmission to the engine, a substantially disk-shaped drive plate is fixed to the crankshaft with bolts. At this time, the drive plate is fixed while being centered on the crankshaft. And
After centering the case of the torque converter and the crankshaft and fixing the transmission to the engine, the drive plate and the torque converter case are bolted, and a tool such as a socket wrench is used from the engine side. Will be concluded.

A fastening surface between the drive plate and the torque converter case is formed so as to be parallel to a plane orthogonal to the axis of the torque converter case, and bolts are fastened along the axial direction of the torque converter case. . By the way, for example, in a hybrid electric vehicle or the like, it is conceivable to adopt a structure in which a motor is sandwiched between an engine and a transmission (for example, Japanese Patent Laid-Open No. 5-1).
(See No. 11215 Publication).

In this case, as described above, when trying to fasten the drive plate and the torque converter case along the axial direction of the torque converter case, the motor between the engine and the transmission becomes an obstacle, and the bolt causes The fastening work becomes difficult.

[0005]

Therefore, a boss member having a bolt through hole is provided on the outer peripheral edge of the torque converter case, and the bolt is passed from the torque converter side through the boss member to the peripheral edge of the drive plate. A structure in which the drive plate is fastened by being screwed into the female screw of the provided boss is conceivable.

However, in the structure in which the boss member is simply fixed to the fastening portion on the drive plate, the centrifugal force acts on the boss member having a larger weight than the other portions of the drive plate, so that the plate of the boss member fixing portion is large. Extends in the outer peripheral direction, and the plate warps on the side opposite to the boss member, that is, on the torque converter side.

Further, a large stress is generated in the plate of the boss member fixing (welding) portion, and a large stress is also generated in the boss member while the female screw is largely deformed due to the stress concentration, so that the strength of these plates and the boss member is greatly reduced. It will end up. The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a fastening structure for a torque converter that can suppress the stress concentration of the drive plate and secure the strength.

[0008]

Therefore, in the invention according to claim 1, the drive plate, which rotates in synchronization with the engine output shaft and whose peripheral portion is fastened to the torque converter case, is fastened to the torque converter case. The structure is such that a boss portion formed with a female screw that is fastened together by a bolt to the torque converter case is integrally formed with a part of a ring member connected in an annular shape and fixed to a peripheral portion of the drive plate body on the engine side. In addition, the radial thickness on the outer peripheral side of the female thread of the boss portion is formed to be equal to the radial thickness of the portion of the ring member other than the boss portion.

According to the first aspect of the present invention, by integrally forming the plurality of boss portions on the ring member, the rigidity is enhanced and the magnitude of the stress generated in the ring member can be reduced. The stress can be dispersed by making the thickness of the thin portion equal to the thickness of the portion of the ring member other than the boss portion in the same direction.

As a result, radial deformation and axial warpage of the ring member are suppressed, and strength can be secured. Further, the invention according to claim 2 is characterized in that an inner peripheral surface of a portion other than the boss portion of the ring member is formed into a tapered surface inclined with respect to an axial direction parallel to the central axis of the ring member. To do.

According to the second aspect of the present invention, the rigidity of the ring member can be increased by increasing the thickness on one side while ensuring the function of dispersing the above-mentioned stress at the thin portion as the tapered surface. Therefore, it is possible to reduce the difference in the amount of displacement in the radial direction between the end faces on the both sides in the axial direction, and to suppress the warp in the axial direction more effectively.

The invention according to claim 3 is characterized in that the tapered surface is inclined in a direction in which the wall thickness increases toward the engine. According to the invention of claim 3, it has been confirmed that when tilted in this direction, axial warpage can be suppressed more effectively than when tilted in the opposite direction.

According to a fourth aspect of the present invention, an intersection angle formed by the tapered surface and an end surface of the ring member on the engine side is defined by:
It is characterized in that it is set to be equal to or less than a predetermined angle near 45 °. According to the invention of claim 4, the intersection angle is 45 °.
It was confirmed that the difference between the radial displacements of both end faces in the axial direction can be kept small and the warp in the axial direction can be effectively suppressed by setting the angle to be equal to or less than the predetermined angle in the vicinity.

According to a fifth aspect of the invention, the angle of intersection between the tapered surface and the end surface of the ring member on the engine side is defined by:
It is characterized in that the angle is set to about 45 °. According to the invention of claim 5, by setting the intersection angle to an angle in the vicinity of 45 °, the difference between the radial displacements of the end faces on both sides in the axial direction is minimized, and the warp in the axial direction is most effectively achieved. It was confirmed that it can be suppressed.

The invention according to claim 6 is characterized in that the ring member is fixed to the drive plate body by welding. According to the invention of claim 6, the strength of the welded portion can be secured by applying each of the above inventions.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. As shown in FIGS. 1 and 2, a motor 2 is connected to an end of a crankshaft 1 of an engine, and a drive plate 3 is attached to the output shaft of the motor 2 so that its center is fastened to rotate in synchronization with the engine 1. . A peripheral portion of the drive plate 3 and a boss member 41 fixed to a peripheral wall of the torque converter case 4 are
By fastening the bolts 5 from the torque converter side, the engine 1 and the automatic transmission are connected.

That is, as shown in FIG. 2 (A), a boss portion in which female screws 33 are formed at a plurality of locations corresponding to the boss member 41 of the torque converter case 4 (for example, four locations at every 90 ° in the circumferential direction). 32 is integrally formed with a part of a ring member 31 connected in an annular shape, and the ring member 31 is fixed to a peripheral portion of the drive plate body 30 on the engine side.

The radial thickness B of the boss portion 32 on the outer peripheral side of the female screw 33 is formed to be equal to the radial thickness A of the ring member 31 other than the boss portion 32. In this way, first, the boss portions 41 at a plurality of locations are separated from each other by the ring member 31.
The rigidity can be strengthened by integrally forming and connecting them in an annular shape. In addition, since unnecessary thick portions (hatched in FIG. 2A) other than the boss portion 32 of the ring member 31 are removed, centrifugal force generated in the entire ring member 31 including the boss portion 32 is eliminated. It can be made sufficiently small, and as a result, the stress generated in the ring member 31 can be made small.

Further, when the boss members are individually provided, or as shown in FIG. 2B, the thickness of the portion other than the boss portion of the ring member is made larger than the thin portion in the outer diameter direction of the female screw of the boss portion. In this case, stress concentrates on the thin portion, but in the present embodiment, the thickness B of the thin portion of the boss portion 32 in the same direction and the thickness A of the portion of the ring member other than the boss portion 32 in the same direction. The stress can be dispersed by making the above equal.

As described above, due to the synergistic effect of reducing the magnitude of stress and preventing the concentration of stress, radial deformation of the ring member 31, axial warpage, etc. can be effectively suppressed, and the shaft can be effectively prevented. The strength can be secured without increasing the directional length. Next, a second embodiment will be described.
In this embodiment, the warp of the ring member in the axial direction can be suppressed more effectively.

As shown in FIGS. 3 and 4, the ring member 3
The inner peripheral surface 31a of the portion other than the boss portion 32 of No. 1 is formed into a tapered surface that is inclined so that the wall thickness increases as the distance from the drive plate main body 30 increases, that is, as the engine approaches. The intersection angle formed by the inner peripheral surface 31a of the ring member 31 and the end surface on the engine side perpendicular to the axis is 45 °.
In the vicinity.

With this configuration, when the drive plate rotates, the displacement amount (increase amount) Δb of the wall thickness Ab of the illustrated ring member on the engine side end portion due to the centrifugal force and the wall thickness Aa of the end portion of the drive plate main body 30 side. It has been experimentally confirmed that there is almost no difference from the displacement amount Δb (also in the boss portion 32), and as a result, axial warpage of the ring member 31 can be suppressed more effectively (see FIG. 5 (A)). , The figure (B)
Shows the principle of warpage when a tapered surface is not used}.

It is to be noted that, when the crossing angle is set to about 45 ° as described above by the experiment, the engine can be used both in the rectangular boss portion 32 of the ring member 31 and in the trapezoidal cross-section portion other than the boss portion 32. Side edge and drive plate body 3
It was found that the displacement amounts of the wall thicknesses at the 0-side end portion (total of 4 places) were almost equal, and it was most effective in preventing warpage. On the other hand, if the crossing angle is larger than about 45 °, it has been found that the difference in the displacement amount between the end portions of the boss portion increases, which is not preferable.

On the other hand, in the direction in which the intersection angle is smaller than around 45 °, the difference in displacement amount can be kept small. However, reducing the crossing angle while keeping the axial length constant increases the cross-sectional shape of the ring member. In addition, the inclination direction of the tapered surface is reversed,
That is, an experiment was carried out by comparing the inner peripheral surface of the boss portion whose inner wall surface is inclined so that the wall thickness increases as it approaches the drive plate body, with that in the inclination direction (forward direction) of the above embodiment. As a result, the difference in displacement when the crossing angle (in the case of the opposite tilt direction is defined as the crossing angle between the end surface on the drive plate body side and the inner peripheral surface) is the same, the difference in displacement is greater than in the forward direction. However, it is smaller than that without taper, and in particular, the difference in displacement amount can be made relatively small in the vicinity of 45 °.

In this embodiment, the smallest axial thickness is set to be equal to or slightly smaller than the radial thickness of the boss portion on the outer peripheral side of the female screw.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a main part of a first embodiment of the present invention.

FIG. 2 is a perspective view showing a main part of the above embodiment and a view for comparing effects of the embodiment.

FIG. 3 is a perspective view showing a main part of a second embodiment of the present invention.

FIG. 4 is a sectional view showing a main part of the same embodiment.

FIG. 5 is a diagram showing an effect of the above embodiment in comparison with a case where the configuration of the embodiment is not provided.

[Explanation of symbols]

1 crankshaft 2 motor 3 drive plate 4 Torque converter case 30 Drive plate body 31 Ring member 32 Boss 31a inner peripheral surface

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kyoko Kobayashi             Kanagawa Prefecture Zama City Hibarigaoka 5-chome 79th No. 1             Chichi no Ichi Nissan Techno Co., Ltd. (72) Inventor Akira Kihara             Kanagawa Prefecture Zama City Hibarigaoka 5-chome 79th No. 1             Chichi no Ichi Nissan Techno Co., Ltd. (72) Inventor Tetsuro Hayashi             Kanagawa Prefecture Zama City Hibarigaoka 5-chome 79th No. 1             Chichi no Ichi Nissan Techno Co., Ltd.

Claims (6)

[Claims] 1. A drive plate that rotates in synchronism with an engine output shaft and has a peripheral edge portion fastened to a torque converter case, and has a fastening structure with the torque converter case. A boss portion having a female screw to be tightened is integrally formed with a part of a ring member connected in an annular shape to be fixed to the engine side peripheral portion of the drive plate body, and a radial thickness of the boss portion on the outer peripheral side of the female screw is also formed. The drive plate fastening structure is characterized in that the thickness is formed to be equal to the radial thickness of a portion of the ring member other than the boss portion. 2. The inner peripheral surface of a portion other than the boss portion of the ring member is formed as a taper surface inclined with respect to an axial direction parallel to the central axis of the ring member.
The drive plate fastening structure described in. 3. The drive plate fastening structure according to claim 2, wherein the tapered surface is inclined in a direction in which the wall thickness increases toward the engine. 4. The drive plate according to claim 2, wherein the angle of intersection between the tapered surface and the end surface of the ring member on the engine side is set to be equal to or less than a predetermined angle near 45 °. Fastening structure. 5. The drive plate fastening structure according to claim 4, wherein the angle of intersection between the tapered surface and the engine-side end surface of the ring member is set to an angle of about 45 °. 6. The ring member is fixed to the drive plate body by welding.
The drive plate fastening structure according to claim 5.