JPH0989005A - Clutch drum structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for quickly and easily forming an oil supply hole without producing any burrs for a clutch drum having a band-type brake and a multiplate type clutch. SOLUTION: A plurality of spline parts for holding a clutch plate are formed in the inner peripheral part of the cylindrical part 40a of an automatic transmission clutch drum 40 and one spline part 46b is extended in a rear direction and thus longer than the other usual spline part 46a. An oil supplying hole 51 is formed in the extended part of the long spline part 46b by punching. In the manufacture of this clutch drum 40, since a time for machining is short and no burrs are produced, the productivity of the clutch drum 40 is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch drum structure and a clutch drum manufacturing method.

[0002]

2. Description of the Related Art Generally, an automatic transmission for an automobile is provided with a torque converter and a gear type speed change mechanism. The torque converter changes the output torque of an engine and outputs it to a turbine shaft. The shaft torque is further changed and output to the drive wheels. Here, the gear type speed change mechanism is usually a sun gear,
A planetary gear mechanism including a plurality of rotating members such as a ring gear, a pinion gear, and a carrier is provided, and gear shifting is performed by switching a power transmission path inside thereof when gear shifting.

In such an automatic transmission, in order to switch the power transmission path of the gear type speed change mechanism, various clutches for turning on (transmitting) and turning off (disconnecting) torque transmission to a predetermined rotating member, and a predetermined clutch. Various friction elements (friction engagement elements) such as various brakes that turn on (fix) and turn off (release) braking of the rotating member are provided. Here, each friction element is provided with a hydraulic piston, and when the piston is pressed by a hydraulic pressure in a predetermined direction, the friction element is turned on, and when the hydraulic pressure is released, the return spring causes the piston to move to the predetermined direction. The friction element is turned off by moving the friction element in the opposite direction (return direction). In addition to such friction elements, the gear type speed change mechanism does not restrict the rotation of a predetermined rotating member in a certain rotation direction (free state), but locks it in the opposite direction to the above rotation direction (lock state. ) A one-way clutch is also provided.

As a brake which is one of friction elements,
Generally, a multi-plate brake and a band-type brake have been widely used, but in the multi-plate brake, a movable plate that rotates integrally with a rotating member and a fixed plate fixed in the rotating direction are brought into contact with each other. The rotation of the rotating member is stopped. On the other hand, in the band type brake, the rotation of the rotary brake is stopped by bringing the brake band arranged so as to surround the outer peripheral portion of the rotating member into contact with the brake band fastening portion formed on the outer peripheral portion. Has become.

Generally, in an automatic transmission,
A brake and a clutch are often installed together with one rotating member. Specifically, for example, a clutch drum structure in which a band-type brake is provided on the outer peripheral portion of a substantially cylindrical drum and a multi-plate clutch is provided on the inner peripheral portion of the drum has been widely used from the past. Has been.

10 (a) and 10 (b) show an example of a conventional clutch drum structure provided with a band brake and a multi-plate clutch. As shown in FIGS. 10A and 10B, in the conventional clutch drum structure, the cylindrical portion 1 forming a part of the clutch drum 100.
The brake band 101 of the band-type brake is arranged so as to surround the outer peripheral portion (brake band fastening portion) of 03. On the other hand, on the inner peripheral portion of the cylindrical portion 103, a plurality of spline portions 102 (groove portions) for holding a clutch plate (not shown) of the multi-plate clutch are formed. Here, the spline portion 102 is formed on the front portion of the cylindrical portion 103 (on the right side in the positional relationship in FIG. 10A), and the length L thereof is usually the minimum necessary for holding the clutch plate. To be done. Further, since the clutch drum 100 provided with the band type brake is required to have a considerably high rigidity, the wall thickness t of the cylindrical portion 103 is set to a relatively large value (for example, t = 5 mm).

Further, the cylindrical portion 1 of the clutch drum 100
03, at a position corresponding to approximately the center of the brake band 101 in the front-rear direction, an oil supply hole 104 having a small diameter (for example, diameter φ = 3 mm) penetrating the wall of the cylindrical portion is provided, and the oil supply hole 104 is provided at the time of braking. Oil is supplied between the brake band 101 and the outer peripheral portion of the cylindrical portion 103 through the hole 104. In this way, the reason why the oil is supplied at the time of braking is to reduce the shock at the start of braking and to prevent the wear of the brake band 101 or the cylindrical portion 103.

[0008]

By the way, generally, when forming a through hole in a metal plate, various processing methods are used. However, punching, which is one of the processing methods, requires a very short time for processing. Therefore, it has an advantage that productivity can be increased. Therefore, the oil supply hole 104 is formed in the cylindrical portion 103 of the clutch drum 100.
Also in the case of forming, if punching can be used, the processing time is shortened and the productivity is improved. However, such a conventional clutch drum 10
When forming the oil supply hole 104 at 0, punching cannot be used as described below. That is, as described above, the press punch corresponding to the diameter of the oil supply hole has a relatively small diameter (for example, 3 mm) even though the wall thickness t of the cylindrical portion 103 is considerably large (for example, 5 mm). This is because the punch often breaks when the oil supply hole 104 is formed by press punching. In general, when the wall thickness t of the cylindrical portion 103 is larger than the diameter φ of the oil supply hole 104,
The punch is often broken.

Therefore, in the conventional clutch drum structure, the oil supply hole 104 is formed by drilling. However, in general, drilling has a problem that productivity is lowered because the time required for drilling is long. Further, in the drilling process, burrs are generated at the time of working, so that a separate step of removing the burrs is required, which further reduces productivity. Thus, in the conventional processing method in which the oil supply hole 104 is formed by drilling, the clutch drum 1
There is a problem that the manufacturing cost of 00 is high.

The present invention has been made in order to solve the above-mentioned conventional problems, and it is quick and easy for a clutch drum provided with a band type brake and a multi-plate type clutch without causing burrs. It is an object of the present invention to obtain a means capable of forming an oil supply hole in the.

[0011]

According to a first aspect of the present invention made to solve the above problems, a plurality of spline portions for holding a clutch plate are formed on an inner peripheral portion,
In a structure of a clutch drum in which a brake band fastening portion that comes into contact with a brake band at the time of braking is formed on an outer peripheral portion, a part of the spline portion is extended so that its entire length is longer than the other spline portions, The extension portion is formed with a hole portion that penetrates the clutch drum wall and opens to the brake band fastening portion. JP-A-2-134447 discloses a transmission gear for an automatic transmission in which a groove (a toothless portion) has a through hole penetrating the gear wall portion. However, this transmission gear structure is The configuration, action, and effect are obviously different from those of the present invention.

According to the structure of the clutch drum of the first aspect, the hole is formed in the extended portion of the spline portion, but in the spline portion, the wall thickness of the clutch drum wall is equal to the depth of the spline portion. Only thin. Therefore, since the wall thickness of the clutch drum wall is sufficiently thin in this portion, the hole can be formed by punching (piercing). Thus, if the hole is formed by punching, the time required for the punching is extremely short, and the productivity of the clutch drum is improved. In addition, since burrs do not occur, the step of removing burrs becomes unnecessary and the productivity is further enhanced. Therefore, the manufacturing cost of the clutch drum is significantly reduced. Since only a part of the spline portion is extended, the rigidity of the clutch drum is not substantially reduced due to the extension of the spline portion, and the rigidity of the clutch drum is sufficiently secured.

A second aspect of the present invention is characterized in that, in the structure of the clutch drum according to the first aspect, the clutch drum is a clutch drum for an automatic transmission of an automobile.

According to the structure of the clutch drum according to the second aspect, the same action and effect as those of the structure of the clutch drum according to the first aspect can be obtained for the clutch drum for the automatic transmission of the automobile. To be Therefore, the productivity of the automatic transmission for automobiles is improved and the manufacturing cost thereof is reduced.

A third aspect of the present invention is a clutch in which a plurality of spline portions for holding a clutch plate are formed on an inner peripheral portion, and a brake band fastening portion which contacts a brake band during braking is formed on an outer peripheral portion. In the method of manufacturing a drum, a spline portion forming step of forming a plurality of spline portions on the inner peripheral portion of the clutch drum so that some of the spline portions are longer than the other spline portions, and the spline portion of the long formed spline portion And a hole forming step of forming a hole penetrating the clutch drum wall and opening to the brake band fastening portion in a portion extended from the other splines.

According to the method of manufacturing the clutch drum of the third aspect, the hole is formed in the spline portion, but the wall thickness of the clutch drum wall in the spline portion is thin by the depth of the spline portion. Has become. Therefore, since the wall thickness of the clutch drum wall is thin in this part,
The holes are easily formed, the productivity of the clutch drum is improved, and the manufacturing cost thereof is reduced. Since only a part of the spline portion is formed to be long, the rigidity of the clutch drum does not substantially decrease, and the rigidity of the clutch drum is sufficiently ensured.

A fourth aspect of the present invention is characterized in that, in the clutch drum manufacturing method according to the third aspect, the hole portion is formed by punching in the hole portion forming step. is there.

According to the clutch drum manufacturing method of the fourth aspect, basically, the same operation and effect as those of the clutch drum manufacturing method of the third aspect can be obtained. Furthermore, the hole is punched (piercing)
Since it is formed by, the time required for the processing is extremely shortened and the productivity of the clutch drum is improved. In addition, since burrs do not occur, the step of removing burrs becomes unnecessary and the productivity is further enhanced. Therefore, the manufacturing cost of the clutch drum is significantly reduced.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below. First, the schematic structure and function of an automatic transmission for an automobile having a clutch drum structure according to the present invention will be described. As shown in FIGS. 4 and 5, the automatic transmission AT for a vehicle basically uses the torque converter 1 to output engine output torque (crankshaft torque).
The speed of the turbine shaft 2 is changed and output to the turbine shaft 2, and the torque of the turbine shaft 2 is changed by the gear type speed change mechanism 3 and output to the primary gear 4. And
Although not shown, the torque of the primary gear 4 is adapted to be transmitted to the drive wheels via a power transmission mechanism including an intermediate gear, an intermediate shaft, a final gear, a differential device, an axle shaft and the like. Note that, for convenience sake, in the following, as viewed in the axial direction of the turbine shaft 2 (left and right in FIGS. 4 and 5), the torque converter side (see FIG.
Further, the right side in FIG. 5 is called "front", and the opposite direction is called "rear".

The torque converter 1 is arranged near the front end portion of the automatic transmission AT, and is substantially connected to a crankshaft (not shown) via a pump case 5 to rotate integrally with the crankshaft. Impeller),
A turbine shaft 2 that is arranged so as to face the pump 6 and is rotationally driven by hydraulic fluid discharged from the pump 6.
A turbine 7 (turbine runner) which is connected to the turbine shaft 2 and rotates integrally with the turbine shaft 2, and a working oil which is disposed between the pump 6 and the turbine 7 and which flows back from the turbine 7 to the pump 6 in a direction for assisting the rotation of the pump 6. It is composed of a stator 8 for rectifying. Then, the torque converter 1 basically outputs the engine output torque to the pump 6 and the turbine 7.
The speed is changed at a speed ratio determined according to the difference in the number of revolutions between the output and the output to the turbine shaft 2. here,
The stator 8 is fixed to a mission case 11 (fixed portion) via a stator one-way clutch 9 and a support member 10. Further, an oil pump 12 for supplying hydraulic oil to a hydraulic mechanism (not shown) of the automatic transmission AT is disposed slightly behind the torque converter 1, and the oil pump 12 is provided with a pump 6 via a connecting member 13. It is designed to be driven by rotation.

Further, the torque converter 1 is disposed between the vertical wall portion of the pump case 5 and the turbine 7 when viewed in the front-rear direction, and in a predetermined operating region where the torque increasing action of the torque converter 1 cannot be expected, the fuel consumption is reduced. A lockup clutch 14 that directly connects the pump case 5 (crankshaft) and the turbine shaft 2 is provided to improve the performance.

The gear type speed change mechanism 3 includes a torque converter 1
The first planetary gear mechanism 15 arranged on the front side behind the vehicle
And a second planetary gear mechanism 16 arranged on the rear side of the planetary gear system, the range (P, R, N,
(D, L range, etc.) and the shift speed (1st to 4th speed) can be switched.

Specifically, the first planetary gear mechanism 15 includes
A first sun gear 17 loosely fitted to the turbine shaft 2;
A first carrier 18 whose front end is connected to the primary gear 4 and rotates integrally with the primary gear 4;
8, which is rotatably supported by the first sun gear 17
A first pinion gear 19 that meshes with the first pinion gear 19 and a first ring gear 20 that meshes with the first pinion gear 19 are provided.

On the other hand, the second planetary gear mechanism 16 is loosely fitted in the turbine shaft 2 (more specifically, loosely fitted in the second carrier 23 described later, which is loosely fitted in the turbine shaft 2). A sun gear 22, a second carrier 23 whose front part is connected to the first ring gear 20 and rotates integrally with the first ring gear 20, and a second gear 23 which is rotatably supported by the second carrier 23 and meshes with the second sun gear 22. A second pinion gear 24 and a second pinion that is connected to the rear end of the first carrier 18 and rotates integrally with the first carrier 18.
A ring gear 25 is provided.

In the gear type speed change mechanism 3, various hydraulic friction elements for switching the power transmission paths inside the two planetary gear mechanisms 15 and 16 and rotation of a predetermined rotating member in only one direction. A limiting one-way clutch is provided. Specifically, in the vicinity of the front end portion of the gear type speed change mechanism 3, a first connecting member 28 that is connected to the first sun gear 17 and rotates integrally with the first sun gear 17, and the turbine shaft 2
A forward clutch 29 that connects and disconnects (on / off) is provided. Further, in the vicinity of the rear end of the gear type speed change mechanism 3, a second connecting member 31 that is connected to the second sun gear 22 and rotates integrally with the second sun gear 22, and the turbine shaft 2
A reverse clutch 32 is provided that connects and disconnects (on / off) a third connecting member 35 that is connected to the turbine shaft 2 and rotates integrally with the turbine shaft 2. Further, a 3-4 clutch 30 that connects (turns on / off) the second carrier 23 and the third connecting member 35 is provided near the rear end of the gear type speed change mechanism 3.

A second connecting member 31 is further fixed / released (on / off) near the rear end of the gear type speed change mechanism 3.
A band type 2-4 brake 33 is provided so as to surround the outer periphery of the reverse clutch 32.
Further, a low reverse brake 34 that fixes / releases (on / off) the second carrier 23 is provided at a position slightly forward of the first planetary gear mechanism 15. Also, the first
A one-way clutch 37, which is arranged between the second carrier 23 and the mission case 11 and limits the rotation direction of the second carrier 23 to only one direction, is provided at a position slightly closer to the front than the planetary gear mechanism 15. .

Here, each of the above friction elements 29, 30, 3
Although not shown in detail, the reference numerals 2, 33 and 34 are adapted to be turned on / off by hydraulic oil or hydraulic pressure supplied / discharged from a hydraulic mechanism controlled by a control unit. And each friction element 29, 30, 32, 3
The power transmission paths inside the two planetary gear mechanisms 15 and 16 are set according to the ON / OFF patterns of 3 and 34, and a desired range or shift speed is set.
The range is set by the driver's operation of the shift lever, but the shift speed is automatically set by the control unit according to the vehicle speed, the throttle opening, and the like. Table 1 shows the relationship between the operating state of each of the friction elements 29, 30, 32, 33, 34 and the one-way clutch 37 and the range or shift speed.

[0028]

[Table 1]

The gear shifting characteristics of the gear type gear shifting mechanism 3 in each range or gear are as follows. In the P range or N range, all friction elements 29, 30, 3
2, 33 and 34 are turned off, the torque of the turbine shaft 2 is not input to the gear type speed change mechanism 3, and therefore the drive wheels are not driven.

In the R range, the reverse clutch 32 and the low reverse brake 34 are turned on, and the other friction elements are turned off. At this time, the torque of the turbine shaft 2 is transmitted to the second sun gear 22 via the reverse clutch 32 and the second connecting member 31. On the other hand, since the low reverse brake 34 is turned on, the first ring gear 20
The (second carrier 23) is fixed. At this time, the second sun gear 22, the second pinion gear 24, and the second ring gear 2
5 and 5 form a fixed gear train that meshes in this order.
The ring gear 25 and thus the primary gear 4 are opposite to the turbine shaft 2 with a gear ratio (b / a) larger than 1 determined by the number of teeth a of the second sun gear 22 and the number of teeth b (b> a) of the second ring gear 25. Driven to rotate. And
The torque of this primary gear 4 is output to the drive wheel side,
The drive wheels are driven backwards with high torque. The gear ratio here means a torque ratio. Further, the number of gear teeth is almost proportional to the gear diameter.

In the first speed in the D range, the forward clutch 2
9 is turned on and the other friction elements are turned off. At this time,
The torque of the turbine shaft 2 is the forward clutch 29.
And transmitted to the first sun gear 17 via the first connecting member 28. In this case, the first ring gear 20 (second carrier 23) is rotationally driven in the direction opposite to the turbine shaft rotation direction, that is, in the direction that locks the one-way clutch 37, but the rotation of the first ring gear 20 (second carrier 23) is one-way. It is locked by the clutch 37. Therefore, the second ring gear 25, and thus the primary gear 4
Is greater than 1 which is determined by the number c of teeth of the first sun gear 17 and the number d of teeth of the first ring gear 20 (d> c) ((c
It is driven to rotate in the same direction as the turbine shaft 2 by + d) / c). Then, the torque of this primary gear 4 is output to the drive wheel side, and the drive wheel is driven in the forward direction with high torque. Since the one-way clutch 37 is in the free state during coasting (during non-driving), the power train is not reversely driven by the drive wheels, and therefore engine braking cannot be obtained. However, in the L range first speed, the low reverse brake 3
Since No. 4 is turned on, engine braking can be obtained at the coast.

In the D range second speed or the L range second speed, the forward clutch 29 and the 2-4 brake 33 are turned on, and the other friction elements are turned off. At this time, by the 2-4 brake 33, the second connecting member 31 (second sun gear 2
Since 2) is fixed, the first ring gear 20 (second carrier 23) rotates in the same direction as the turbine shaft 2. Therefore, in this case, as compared with the case of the first speed in the D range, the amount of rotation of the first ring gear 20 (second carrier 23) corresponds to the amount of rotation of the second ring gear 25 and thus the primary gear
Rotation speed increases, and the gear ratio decreases accordingly.
Therefore, the drive wheels are driven in the forward direction with a torque that is slightly lower than that in the first speed in the D range (higher than that in the third speed).

In the third speed in the D range or the third speed in the L range, the forward clutch 29 and the 3-4 clutch 30 are turned on and the other friction elements are turned off. At this time, both planetary gear mechanisms 15 and 16 are in a locked state, so that the turbine shaft 2 and the primary gear 4 are directly connected to each other and the gear ratio is 1. In this case, the drive wheels are driven in the forward direction with a torque lower than that in the second speed, which corresponds to the gear ratio 1.

In the D range 4th speed or the L range 4th speed, 3-
The 4-clutch 30 and the 2-4 brake 33 are turned on, and the other friction elements are turned off. At this time, the torque of the turbine shaft 2 is transmitted to the second carrier 23 via the 3-4 clutch 30. On the other hand, since the second sun gear 22 is fixed by the 2-4 brake 33, the second ring gear 2
5 and the primary gear 4 and the turbine shaft 2 with a gear ratio (b / (a + b)) smaller than 1 determined by the number of teeth a of the second sun gear 22 and the number of teeth b (b> a) of the second ring gear 25. The wheels are driven to rotate in the same direction, and the driving wheels are driven in the forward direction with a low torque corresponding to a gear ratio smaller than 1 (overdrive state).

Next, the specific mechanical structure of the automatic transmission AT will be described. The general mechanical structure of the automatic transmission AT is well known, and such general mechanical structure is the gist of the present invention. Since there is no place to say, omit the explanation,
Hereinafter, only a specific mechanical structure of a portion related to the clutch drum according to the present invention will be described. As is clear from FIG. 5, in the vicinity of the rear end of the automatic transmission AT,
A second connecting member 31, a third connecting member 35, a reverse clutch 32, and a 2-4 brake 33 are arranged. Here, the second connecting member 31 is a cylindrical portion 4 having a substantially cylindrical shape.
0a and a rear end wall 40b extending in a direction orthogonal to the turbine shaft axis are included in the clutch drum 40. Here, since the clutch drum 40 is required to have high rigidity, the wall thickness of the cylindrical portion 40a is set to a relatively large value (for example, 5 mm). In addition, the third connecting member 35 includes an inner drum 45 that is disposed in the cylindrical portion 40a and that includes a substantially cylindrical tubular portion 45a and a rear surface wall 45b. The reverse clutch 32 is arranged inside the cylindrical portion 40a and outside the cylindrical portion 45a, while the 2-4 brake 33 is arranged outside the cylindrical portion 40a.

As shown in FIGS. 6 and 7, the reverse clutch 32 has a plurality of outer sides which are engaged with a plurality of spline portions 46 (grooves) formed on the inner peripheral portion of the cylindrical portion 40a and are held thereby. The clutch plate 47 and a plurality of outer splines 4 formed on the outer peripheral portion of the tubular portion 45a.
There are a plurality of inner clutch plates 49 engaged with and held by the eight. A snap ring 50 is attached to the spline portion 46.
Here, the outer clutch plates 47 and the inner clutch plates 49 are alternately arranged in the front-rear direction. The specific shapes of the outer clutch plate 47 and the inner clutch plate 49 are shown in FIGS. 8 and 9, respectively.
As shown in FIG. A hydraulic piston 41 is fitted in the clutch drum 40 on the rear side of the plate group including the clutch plates 47 and 49 of both types.
The hydraulic piston 41 is always biased rearward by the return spring 42.

Here, when hydraulic oil (hydraulic pressure) is supplied to the oil chamber 43 defined on the rear side of the hydraulic piston 41, the hydraulic piston 41 is pushed forward (X ₁ direction) by the hydraulic pressure and The front end portion presses the plate group forward, and as a result, the outer clutch plate 47 and the inner clutch plate 49 adjacent to each other are frictionally engaged with each other, and the reverse clutch 32 is turned on (fastened). On the other hand, hydraulic oil in the oil chamber 43
When the (hydraulic) pressure is released, the return spring 42 moves the hydraulic piston 41 rearward (in the X ₂ direction), releasing the frictional engagement between the outer clutch plate 47 and the inner clutch plate 49 to reverse clutch. 32 is turned off (released).

On the other hand, the 2-4 brake 33 has a brake band 39 arranged so as to surround the outer peripheral portion (brake band fastening portion) of the cylindrical portion 40a of the clutch drum 40.
And a hydraulic servo piston mechanism (not shown) that tightens or releases the brake band 39 on the cylindrical portion 40a. Although not shown, the servo piston mechanism is provided with an apply-side oil chamber and a release-side oil chamber that are partitioned from each other by the servo piston, and basically, hydraulic pressure is supplied to the apply-side oil chamber. At times, the brake band 39 is tightened to come into contact with the outer peripheral portion of the cylindrical portion 40a, and the 2-4 brake 33
Is turned on. On the other hand, when hydraulic pressure is supplied to the release side oil chamber, the contact is released,
The 4 brake 33 is turned off.

By the way, when the 2-4 brake 33 is turned on, the shock at the start of braking is reduced and the brake band 39 is applied as described above.
Or, in order to prevent wear of the cylindrical portion 40a, it is necessary to supply oil between the brake band 39 and the outer peripheral portion (brake band fastening portion) of the cylindrical portion 40a. Therefore, an oil supply hole 51 having a small diameter (for example, a diameter of 3 mm) that penetrates the wall of the cylindrical portion is provided at a position of the cylindrical portion 40a of the clutch drum 40 that corresponds to approximately the center of the brake band 39 when viewed in the front-rear direction. During braking, oil is supplied between the brake band 39 and the outer peripheral portion of the cylindrical portion 40a through the oil supply hole 51.

As shown in FIGS. 1 (a) and 2, the inner peripheral portion of the cylindrical portion 40a of the clutch drum 40 has a predetermined depth (for example, 2) extending in the clutch drum axial direction (front-back direction). ~ 3 mm) multiple spline parts 46
(Grooves) are formed (36 in the example shown in FIG. 2).
Some of these splines 46b (in the example shown in FIG. 2, one in four at equal intervals, that is, nine in total) are formed over substantially the entire length of the cylindrical portion 40a when viewed in the front-rear direction. (Hereinafter, these spline parts 4
6b is called long spline part 46b). However, other spline portions 46a (2 in the example shown in FIG.
7) are formed in the front portion of the cylindrical portion 40a with the same length as in the case of the conventional clutch drum as shown in FIG. 10 (hereinafter, these spline portions 46a are referred to as normal spline portions 46a). . The length of the normal spline portion 46a is set to a minimum value required to hold the outer clutch plate 47 or a value slightly larger than this.

A clutch drum 4 having such a normal spline portion 46a and a long spline portion 46b.
0 is, for example, the spline portion 46 (46a, 46b)
Is formed by forging such as press-fitting into the cylindrical portion 40a of the clutch drum 40 where the spline portion 46 is not formed yet, or roll forming. Therefore, the two types of spline portions 46a and 4a
The clutch drum 40 provided with 6b is easy to manufacture.
In addition, since only a small number of long spline portions 46b are formed to be long, the rigidity of the clutch drum 40 does not substantially decrease due to the extension of the spline portion, and the rigidity of the clutch drum 40 is sufficiently secured. It

The oil supply hole 51 is a portion (extension) of the long spline portion 46b at the rear side of the rear end portion of the normal spline portion 46a at a position corresponding to substantially the central portion of the brake band 39 when viewed in the front-rear direction. part),
That is, it is formed in a portion where the outer clutch plate 47 is not arranged. It should be noted that these oil supply holes 51 penetrate the wall of the cylindrical portion and open to the outer peripheral portion (brake band fastening portion) of the cylindrical portion 40a.

As described above, the oil supply hole 51 is formed in the long spline portion 46b. In this portion, the wall thickness of the cylindrical portion 40a is equal to the depth of the long spline portion 46b (for example, 2 to 3 mm) thinner. Therefore, in this portion, the wall thickness of the cylindrical portion 40a becomes sufficiently thin (normally, the wall thickness is the oil supply hole 51).
The diameter of the oil supply hole 51 is equal to or less than the above), and formation of the oil supply hole 51 becomes extremely easy. Therefore, various drilling methods that could not be used conventionally, such as punching, can also be used.

Therefore, in this embodiment, the oil supply hole 51 is formed by punching (piercing) using a press punch. Such oil supply hole 5
For example, as shown in FIG. 3, 1 indicates a cylindrical portion 40 of the clutch drum 40 at a position where the oil supply hole 51 is to be formed.
It is formed by arranging the backup metal fitting 56 in contact with the inner peripheral surface of a and arranging the press punch 55 in the Y direction. As described above, since the oil supply hole 51 is formed by punching, the time required for the machining is extremely short, and the productivity of the clutch drum 40 is improved. In addition, since burrs unlike in the case of drilling are not generated, the step of removing burrs is not required, and the productivity of the clutch drum 40 is further enhanced.
Therefore, the manufacturing cost of the clutch drum 40 is significantly reduced.

In the above embodiment, only some of the spline portions 46b are lengthened and the other spline portions 46a are made longer.
1 has the same length as the conventional one, but a method of lengthening all the spline portions 46b as shown in FIG. 1B is also possible. However, in this case, the rigidity of the clutch drum 40 is reduced.

Further, in the above embodiment, the long spline portion 46b is formed over substantially the entire length of the cylindrical portion 40a as viewed in the front-rear direction, but the long spline portion 46b is formed at the position where the oil supply hole 51 should be formed. It may be formed to the slightly rear side. By doing so, the rigidity of the clutch drum 40 is increased by the length of the long spline portion 46b.

[Brief description of drawings]

FIG. 1 (a) is a partial perspective explanatory view of a clutch drum in which some spline portions are elongated according to the present invention, and FIG. 1 (b) is a partial perspective view of a clutch drum in which all spline portions are elongated. It is isometric view explanatory drawing.

2 is a front explanatory view of an upper half portion of the clutch drum shown in FIG. 1 (a). FIG.

FIG. 3 is a side cross-sectional explanatory view of a clutch drum with punching means, showing a method for forming an oil supply hole.

FIG. 4 is a schematic diagram showing a schematic configuration of an automatic transmission including a clutch drum according to the present invention.

FIG. 5 is a side sectional view showing an automatic transmission including a clutch drum according to the present invention.

6 is an enlarged side cross-sectional explanatory view around a clutch drum of the automatic transmission shown in FIG.

7 is an enlarged side cross-sectional explanatory view around a clutch drum of the automatic transmission shown in FIG.

FIG. 8 is a front explanatory view of the upper half of the outer clutch plate.

FIG. 9 is a front explanatory view of the upper half of the inner clutch plate.

10 (a) is a side sectional view of a conventional clutch drum, and FIG. 10 (b) is a front view of the upper half of the clutch drum shown in FIG. 10 (a).

[Explanation of symbols]

 AT ... Automatic transmission 1 ... Torque converter 2 ... Turbine shaft 3 ... Gear type transmission mechanism 4 ... Primary gear 31 ... Second connecting member 32 ... Reverse clutch 33 ... 2-4 brake 35 ... Third connecting member 39 ... Brake band 40 , 40 '... Clutch drum 40a ... Cylindrical part 46 ... Spline part 46a ... Normal spline part 46b ... Long spline part 51 ... Oil supply hole 55 ... Press punch 56 ... Backup metal fitting

Claims (4)

[Claims] 1. A structure of a clutch drum, wherein a plurality of spline portions for holding a clutch plate are formed on an inner peripheral portion, and a brake band fastening portion that abuts a brake band during braking is formed on an outer peripheral portion. A part of the spline portion is extended so that its entire length is longer than the other spline portions, and a hole portion that penetrates the clutch drum wall and opens to the brake band fastening portion is formed in the extension portion. Characteristic clutch drum structure. 2. The structure of the clutch drum according to claim 1, wherein the clutch drum is a clutch drum for an automatic transmission of an automobile. 3. A method for manufacturing a clutch drum, wherein a plurality of spline portions for holding a clutch plate are formed on an inner peripheral portion, and a brake band fastening portion that contacts a brake band during braking is formed on an outer peripheral portion. Spline part forming step of forming multiple spline parts on the inner peripheral part of the clutch drum so that the spline part of the long part is longer than other spline parts, and extending the spline part of the long formed spline part from other splines And a hole forming step of forming a hole penetrating the clutch drum wall and opening to the brake band fastening portion. 4. The method for manufacturing a clutch drum according to claim 3, wherein in the hole forming step, the hole is formed by punching.