JPH0814357A - Lockup piston of torque converter, manufacture thereof, and device for manufacturing same - Google Patents

Abstract

PURPOSE:To provide a device for manufacturing a lockup piston, whereby any desired portion of the lockup piston can be hardened without being press tempered, resulting in reduced manufacturing costs. CONSTITUTION:A work rotation means 11 rotates the claw 6 of a lockup piston material 1a to a predetermined position where a partial heating means 12 is located. The claw 6 of the lockup piston material 1a is partially heated by the partial heating means 12. The heated portion of the claw 6 is quenched by a cooling liquid ejected from a cooling liquid ejection means 13, and part of the claw 6 is hardened. As a result, thermal distortion due to the hardening does not occur in the lockup piston material 1a except the part (hardened part) of the claw 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lockup piston for a hydraulic torque converter used in an automatic transmission,
The manufacturing method and manufacturing apparatus are related.

[0002]

2. Description of the Related Art Generally, a torque converter has a built-in lock-up clutch 41 as shown in FIG. 8, and when the vehicle speed exceeds a certain speed, the lock-up clutch 41 is frictionally engaged with a front cover 42. , The front cover 42 and the output shaft 43 with the lockup clutch 41
The engine power is transmitted to the output shaft 43 without passing through a fluid to improve the fuel efficiency of the engine (see, for example, Japanese Patent Laid-Open No. 62-252958).

Particularly, in the torque converter 40 developed in recent years, the rotational speeds of the front cover 42 and the output shaft 43 are in a low / medium speed range until the lockup clutch 41 is completely frictionally engaged with the front cover 42. Difference is 50-1
By further controlling the slip-up of the lock-up clutch 41 so that the speed becomes 00 rpm, the fuel consumption is further improved.

As described above, the lock-up clutch 41, which plays an important role in improving fuel economy, moves axially under the pressure of fluid and frictionally engages with the front cover 42, and the lock-up piston 45. It comprises a lock-up piston 45 and a damper 46 that connects the output shaft 43. The lock-up clutch 41 reliably transmits the power from the lock-up piston 45 to the damper 46. Therefore, as shown in FIG. 9, the lock-up clutch 41 has a plurality of engaging portions 48 in the outer circumferential direction of the drive plate 47 of the damper 46. Is formed as a notch, and the lockup piston 45 is formed in the engaging portion 48.
The tongue-shaped claws 49 are engaged with each other.

Therefore, when the power is transmitted by the lockup clutch 41, a large force acts on the abutting portion of the claw 49 of the lockup piston 45 and the engaging portion 48 of the drive plate 47, and thus the claw 49 of the lockup piston 45. It was necessary to improve the wear resistance of the above, and the entire press-up lock-up piston material 45a was carburized / nitrided and quenched (see FIG. 10).

[0006]

However, in the lock-up piston 45 of the conventional torque converter 40 as described above, when the entire lock-up piston material 45a is carburized / nitrogen-quenched, the distortion due to the quenching occurs. And the frictional engagement with the front cover 42 is hindered.

Therefore, conventionally, as shown in FIG. 10, after the press-up lock-up piston material 45a is carburized / nitrided and quenched, the lock-up piston material 4 is
The quenching strain generated in 5a is removed by a press temper, the inner diameter of the lock-up piston material 45a is then finished, and the lining 50 is adhered at a predetermined position to manufacture the desired lock-up piston 45. However, there is a limit to the distortion removal (precision correction) of the lock-up piston material 45a by the press temper,
It was difficult to ensure the accuracy before quenching. or,
In such a conventional method for manufacturing the lock-up piston 45, it takes time to press-temper, and it has not been possible to sufficiently meet the demand for reduction in manufacturing cost.

It is an object of the present invention to provide a lockup piston for a torque converter which does not cause distortion due to quenching in the lockup piston, and a method and apparatus for manufacturing the lockup piston.

[0009]

That is, according to the present invention, the output shaft (43) is frictionally engaged with the front cover (42) of the torque converter (40) according to the traveling condition of the vehicle, and is output through the damper (46). A lockup piston (1) for transmitting torque to a torque converter, comprising: a tongue-shaped pawl (6) engaged with a plurality of engaging portions (48) provided in the circumferential direction of the damper (46). Formed corresponding to the engaging portion (48),
A portion (6) of the claw (6) that comes into contact with the engaging portion (48).
a, 6b) has a locally quenched end portion.

Further, according to the present invention, the torque converter which frictionally engages with the front cover (42) of the torque converter (40) according to the traveling condition of the vehicle and transmits the power to the output shaft (43) through the damper (46). A method of manufacturing a lockup piston (1) according to claim 1, wherein the tongue piece engages with a plurality of engaging portions (48) provided in the circumferential direction of the damper (46) at the outer peripheral end of the lockup piston (1). -Shaped claws (6) are provided, and local heating means (12) is brought close to the claws (6) of the lock-up piston (1) from the side in contact with the engagement part (48) of the damper (46). It is characterized by quenching.

Further, the device (10) for manufacturing the lockup piston (1) of the torque converter according to the present invention comprises the lockup piston material (1a) having a plurality of tongue-shaped claws (6) formed on the outer peripheral end. Workpiece receiving jig to hold (1
7), local heating means (12) for locally heating near the portions (6a, 6b) of the claw (6) that come into contact with the engaging portion (48) of the damper (46), and the local heating. And a cooling liquid jetting means (13) for jetting a cooling liquid to the claw (6) heated to a high temperature by the means (12).

In addition, the present invention provides the local heating means (1
2) is a substantially U-shaped coil (2) in which induction current is generated only in the end portion of the tongue-shaped claw (6) and induction hardening is performed.
It is characterized in that it is 3).

[0013]

In the portions (6a, 6b) of the plurality of tongue-shaped claws (6) provided on the outer peripheral end of the lock-up piston (1), which come into contact with the engaging portion (48) of the damper (46). Since it has a locally quenched end, the frictional engagement surface of the lock-up piston (1) frictionally engages with the front cover (42) of the torque converter (40) and the plurality of tongue-shaped claws (6). Is engaged with the engaging portion (48) of the damper (46), the locally quenched end portion transmits power while ensuring wear resistance.

The damper (4) is attached to a plurality of tongue-shaped claws (6) provided on the outer peripheral end of the lock-up piston (1).
Since the local heating means (12) is brought close to the side of the engaging portion (48) of (6) that abuts the local heating means (12), only the end of the claw (6) can be quenched and the lock-up piston (1) can be hardened. No distortion is generated on the friction engagement surface of (1).

A lock-up piston material (1a) having a plurality of tongue-shaped claws (6) formed on the outer peripheral edge thereof is held by a work receiving jig (17), and the damper (4) of the claws (6) is held.
The local heating means (12) for locally heating the portion (6a, 6b) abutting the engaging portion (48) of 6) is brought close to the local heating means (12), and the damper (6) of the claw (6) is provided. 46)
The portion contacting the engaging portion (48) of (1) is heated to a high temperature, and the cooling liquid spraying means (13) sprays the cooling liquid onto the claws (6) for local quenching.

Further, since the local heating means (12) is a coil (23) having a substantially U shape surrounding only the end of the tongue-shaped claw (6), the tongue-shaped claw (12) is formed. Only the end of 6) is induction hardened locally.

The reference numerals in the above parentheses are for comparison with the drawings and do not limit the structure of the present invention.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a lock-up piston 1 according to the present invention.
FIG. As shown in FIG. 1, the lock-up piston 1 includes a side plate portion 2 having a substantially hollow disk shape, an outer peripheral cylindrical portion 3 formed by bending at an outer peripheral end of the side plate portion 2, and an inner periphery of the side plate portion 2. It has an inner peripheral cylindrical portion 5 formed to be bent at the end. A plurality of tongue-shaped claws 6 projecting in the axial direction (rightward in the drawing) are formed on the outer peripheral cylindrical portion 3.
A lining 7 that is frictionally engaged with the front cover 42 (see FIG. 8) is adhered to a predetermined position of the side plate portion 2.

The lockup piston 1 is
Both ends of the tongue-shaped claw 6 (portions contacting the engaging portion 48 (see FIG. 9) of the damper 46) 6a are locally induction-hardened as shown by the hatched portion in FIG. The wear resistance of the claw 6 is increased.

Next, such a lock-up piston 1
The manufacturing method will be described based on the process chart shown in FIG.

First, in the press working step, the lock-up piston material 1a having a desired shape is punched from the plate blank 9 by a press. By this press working, the lock-up piston material 1a including the side plate portion 2 having a substantially hollow disk shape, the inner peripheral cylindrical portion 5 and the outer peripheral cylindrical portion 3 provided with the claw 6 is formed.

Next, a heat treatment step (induction hardening step)
In the above, the induction hardening is locally performed on both side end portions 6a and 6b of the respective claws 6 of the lock-up piston material 1a from the side in contact with the engaging portion of the damper. This local induction-hardened lock-up piston material 1a does not cause distortion due to quenching, except near the induction-hardened ends 6a and 6b of the pawl 6, and before and after the heat treatment step. Since there is no change in the shape accuracy, it is possible to directly perform the finishing process without performing the press tempering that has been conventionally performed.

Next, in the finishing step, the inner diameter of the inner cylindrical portion 5 of the lock-up piston material 1a is cut to a predetermined dimensional accuracy.

Next, in the lining bonding step, the lining 7 frictionally engaged with the front cover 42 (see FIG. 8) is bonded to a predetermined position of the side plate portion 2 of the lock-up piston material 1a.

As a result, the lockup piston 1 shown in FIG. 1 is formed.

As described above, according to the method of manufacturing the lockup piston of this embodiment, only the end portions 6a and 6b of the lockup piston 1 where the wear resistance of the claw 6 is required are hardened, and the heat treatment step is performed. Since there is no change in the shape accuracy of the lock-up piston material 1a before and after, the press tempering conventionally performed can be omitted, and the manufacturing time and the manufacturing cost can be shortened.

Further, according to the method for manufacturing the lockup piston of the present embodiment, it is possible to provide the lockup piston 1 with high accuracy, which is free from thermal distortion due to quenching.

Next, a manufacturing apparatus capable of locally induction hardening the claws 6 of the lockup piston 1 will be described.

FIG. 4 is a front view of the lock-up piston manufacturing apparatus, FIG. 5 is a left side view thereof (a view in the direction of arrow A in FIG. 4, and FIG. 6 is a plan view showing a part (control unit) thereof omitted. FIG. 6 is a view as seen from the direction of arrow B in FIG. 5.

As shown in these figures, the lock-up piston manufacturing apparatus 10 includes a work rotating means 11, a local heating means 12, a cooling liquid injection means 13, and control signals to these means 11, 12, and 13. Control unit 1 for outputting
5 and the cooling liquid tank 16.

Among these, the work rotating means 11 rotates the work receiving jig 17 and the work receiving jig 17 for holding the lock-up piston material 1a having a plurality of tongue-shaped claws 6 formed on the outer peripheral end thereof. A work rotation motor 19 that moves the claws 6 sequentially to a predetermined position, and a support base 20 that supports the work receiving jig 17 and the work rotation motor 19.
It consists of

Further, the local heating means 12 is a high frequency power source 21.
And a quenching coil 23 connected to the high frequency power source 21 via a coil mounting base 22. Then, the coil 23, as shown in FIG.
The claw 6 has a substantially inverted U shape so that an induced current can be generated in a part of the claw 6 (one of the shaded portions in FIG. 2) to locally heat the claw 6.

When the claw 6 of the lock-up piston material 1a is rotated to a predetermined position by the work rotating means 11, the local heating means 12 outputs a coil from the high frequency power source 21 based on a signal from the control unit 15. A high-frequency current is supplied to 23 for a predetermined time.

Further, the cooling liquid jetting means 13 applies the cooling liquid to the claws 6.
And a cooling liquid injection jacket 25 for locally quenching the nails 6 (see FIG. 7B), and the cooling liquid is supplied to the cooling liquid injection jacket 25 via the cooling liquid supply pipe 26. It comprises a pump 27 for supplying.

The induction hardening by the local heating means 12 and the cooling liquid jetting means 13 is performed by the local liquid heating means 12 and then by the cooling liquid jetting means 13 as shown in FIG. 7C. By cooling to 1, the claws 6 of the lockup piston 1 are locally quenched.

The coolant tank 16 is the work rotation motor 1
9, the work receiving jig 17, the coil 23, and the cooling liquid jetting jacket 25 are formed so as to surround the cooling liquid jetting jacket 25 so that the cooling liquid jetted from the cooling liquid jetting jacket 25 can be stored therein without spilling to the outside. And this cooling liquid tank 1
A pipe 30 that connects the tank interior 16 a and the pump 27 is provided at the lower end of the tank 6.

According to the lock-up piston manufacturing apparatus 10 of the present embodiment configured as described above, the high-precision lock-up piston 1 shown in FIG. 1 can be manufactured according to the manufacturing method.

In the above embodiment, the high frequency heating is shown as the local heating method, but the local heating may be performed locally by laser beam or electron beam. Further, in the manufacturing apparatus 10 described above, the local heating means 12 and the cooling liquid injection means 13 are appropriately arranged in number according to the shape of the lockup piston 1.

Furthermore, FIGS. 11 and 12 show an example of the shape of the coil 23 of the local heating means 12. As shown in these figures, the coil 23 is bifurcated,
You may make it heat the one end side of the adjacent nails 6 and 6 simultaneously (FIG.11 (a), FIG.12 (a)). The side surface shape of the tip of the coil 23 is shown in FIG.
As shown in FIG. 12B and FIG. 12B, a substantially inverted U surrounding the claw 6 is formed.
It has a letter shape.

[0041]

As described above, the lock-up piston of the present invention comes into contact with the engaging portion of the damper and locally quenches only a part of the tongue-shaped pawl on which a large rotational force acts. Therefore, heat distortion due to quenching does not occur in other parts except for a part of the claws, the claws are molded with high shape accuracy, and extremely good power transmission can be performed.

Further, according to the method of manufacturing the lock-up piston of the present invention, after a lock-up piston having a desired shape having a tongue-shaped pawl is formed by a press working process, only a part of the pawl requiring abrasion resistance is formed. Since the steel is locally quenched in the heat treatment step, the shape accuracy of the lock-up piston material can be maintained at a desired accuracy even after the heat treatment step. Therefore, according to the manufacturing method of the present invention, since the frictional engagement surface is not distorted by quenching, the press tempering after quenching is not necessary, the number of steps can be reduced, the manufacturing time can be shortened, and the manufacturing cost can be reduced. Can be realized.

Further, in the lock-up piston manufacturing apparatus of the present invention, the claw of the lock-up piston material is moved to a predetermined position, a part of the claw is heated by the local heating means, and then the cooling liquid is injected to the heated part. Since the cooling liquid is jetted and quenched by the means, it can be used in the above-mentioned manufacturing method to manufacture the above-mentioned highly accurate lock-up piston.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a lock-up piston that is an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the lockup piston.

FIG. 3 is a process drawing showing the manufacturing method of the present invention.

FIG. 4 is a front view of the manufacturing apparatus of the present invention.

FIG. 5 is a left side view of the same device (view from the direction of arrow A in FIG. 4).

FIG. 6 is a plan view showing a part of the apparatus with a part omitted (B in FIG. 5).
Direction arrow view).

FIG. 7 is an explanatory diagram of a local quenching process. (A) is a heating process diagram, (b) is a cooling process diagram, (c) is a temperature diagram showing induction hardening conditions.

FIG. 8 is a vertical sectional view of a main part of the torque converter.

FIG. 9 is a front view of the lock-up clutch with a part cut away.

FIG. 10 is a process drawing showing a conventional method for manufacturing a lockup piston.

FIG. 11 is a diagram showing an example of a coil shape in the lock-up piston manufacturing apparatus of the present invention. (A) is a front view of a main part of the coil, and (b) is a side view of a main part of the coil.

FIG. 12 is a view showing another embodiment of the coil shape in the lock-up piston manufacturing apparatus of the present invention. (A) is a front view of a main part of the coil, and (b) is a side view of a main part of the coil.

[Explanation of symbols]

 1 Lockup Piston 1a Lockup Piston Material 6 Claw 10 Manufacturing Device 11 Work Rotation Means 12 Local Heating Means 13 Coolant Injection Means 23 Coil 40 Torque Converter 42 Front Cover 43 Output Shaft 46 Damper 48 Engagement Part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masato Nakamura 10 Akane Takane, Fujii-cho, Aichi Prefecture Aisin AW Co., Ltd.

Claims (4)

[Claims] 1. A lock-up piston for a torque converter, which frictionally engages with a front cover of the torque converter according to vehicle traveling conditions and transmits power to an output shaft via a damper, wherein a plurality of lock-up pistons are provided in a circumferential direction of the damper. A torque characterized in that a tongue-shaped claw engaged with the joint is formed corresponding to the engaging part, and the end of the claw that abuts the engaging part has a locally quenched end. Converter lock-up piston. 2. A method of manufacturing a lockup piston for a torque converter, which frictionally engages with a front cover of the torque converter according to vehicle traveling conditions and transmits power to an output shaft via a damper, the lockup piston comprising: A tongue-shaped claw that engages with a plurality of engaging portions provided in the circumferential direction of the damper is provided at the outer peripheral end,
A method for manufacturing a lockup piston of a torque converter, wherein local heating means is brought close to a claw of the lockup piston from a side in contact with an engaging portion of the damper to locally quench the lockup piston. 3. A work receiving jig for holding a lock-up piston material having a plurality of tongue-shaped claws formed on an outer peripheral end thereof, and a portion locally adjacent to a part of the claw that abuts with an engaging portion of the damper. An apparatus for manufacturing a lock-up piston for a torque converter, comprising: a local heating unit that heats the claw and a cooling liquid jetting unit that jets a cooling liquid to a claw heated to a high temperature by the local heating unit. 4. The local heating means is a substantially U-shaped coil for induction hardening only at the ends of the tongue-shaped claws and induction hardening. The method or apparatus for manufacturing the lockup piston of the torque converter according to claim 3.