JPH0473452A - Assembly of wheel stator and outer race of torque converter - Google Patents

Abstract

PURPOSE:To simplify manufacture, reduce cost, and increase the degree of freedom of a wheel stator and a retainer by preventing the reduction of hardness of an outer race in casting by cooling the inner peripheral part of the outer race by a center guide in casting. CONSTITUTION:An outer race 8 is prepared through casting, turning work, etc. by using SCM 415, 420, etc., and put into surface hardening treatment through carburization hardening. The outer race 8 is set in the center guide 32 of a metal mold 31, and the metal mold 31 is fitted, and the molten Al material is poured under pressure. Thus, an integral article consisting of a wheel stator and the outer race 8 can be obtained. In this casting work, the hardness of the inner peripheral part of the outer race 8, i.e., the part which requires surface hardness does not reduce, since the part is cooled by the center guide 32. Accordingly, the need of the high frequency hardening after casting is obviated, and the labour for heat treatment can be omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for assembling a wheel stator and an outer race of a torque converter suitable for use in automobiles and other vehicles.

(Prior Art) In general, a three-element one-stage torque converter, as shown in FIG. The pump impeller 2 drives the turbine 4 to increase the rotation of the output shaft 3, and the stator 7 is stopped until the speed ratio reaches the clutch point. However, above the clutch point, the stator 7 begins to rotate relative to the fixed cylinder shaft 5. In the one-way clutch machine H46, the outer race 8 and the retainers 9 and 10 on both sides are fitted to the inner peripheral surface of the wheel stator 7a of the stator 7 by splines or other methods, and the inner race 11 is fitted to the fixed cylinder shaft 5 by splines or other methods. A sprag (one-way clutch actuator) 12 is sandwiched between the inner race 11 and the outer race 8. A radial oil passage 1 is provided between the retainer 9 and the turbine hub 15.
The retainer 9 is also provided with an oil hole 17 that communicates from the oil passage 16 side to the sprag 12 side. Further, in the above structure, the hydraulic oil is subjected to the pumping action of the turbine 4, flows from the turbine 4 side through the oil passage 16, and flows between the output shaft 3 and the fixed cylinder shaft 5, and is pumped to the pump (not shown) or to the transmission. (not shown) and again to passage 1.
A circulation path is formed that flows from the pump impeller 8 to the inlet side of the pump impeller 2.

In such a torque converter, the outer race 8 has conventionally been attached to the inner periphery of the wheel stator 7a by the following method.

(2) Spline-shaped teeth are provided on the inner periphery of the wheel stator 7a and the outer periphery of the outer race 8 to secure the assembly.

(2) Knurling the outer periphery of the outer race 8 and press-fitting it into the inner periphery of the wheel stator 7a.

(2) When casting and forming the foil stator 7a, the outer race 8 is set in a mold in advance and the body is formed.

(Problems to be Solved by the Invention) In the method (2) above, the steel material is case hardened steel, for example, SC.
When M415.420 or the like is used and cast after being carburized and quenched, there is a drawback that the hardness of the outer race 8 decreases because the case hardening steel becomes hot during casting. . Therefore, high carbon steel is generally used and induction hardened to ensure hardness after casting. However, this method requires time and expense to perform induction hardening, resulting in a problem of high cost. In addition, since it is necessary to prevent the foil stator 7a made of aluminum material from melting during induction hardening, the structure around the outer race 8, that is, the foil stator 7a
The structures of the retainers and retainers 9 and 10 were limited.

The present invention provides a torque converter wheel stator that can simplify manufacturing and reduce costs by eliminating heat treatment such as induction hardening after casting, and can increase the degree of freedom in the structure of the wheel stator and retainer. and an outer lace assembly method.

(Means for Solving the Problems) The method for assembling the wheel stator and outer race of the torque converter of the present invention is such that the outer race is assembled by casting on the inner periphery of the wheel stator of the torque converter. The hardened outer race is set in a die-casting mold for forming a foil stator equipped with a cooling center guide, and the center guide cools the inner circumference of the rear outer race during casting. This is characterized by preventing a decrease in the hardness of the outer lace.

(Function) Since the inner circumference of the outer race is cooled by the center guide during casting, the hardness does not decrease.

(Example) Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a longitudinal sectional view showing a torque converter manufactured using the assembly method of the present invention, Fig. 2 is a perspective view of the outer race, and Fig. 3 is a sectional view taken along the line ■-■ of Fig. 2. . In the figure, the same reference numerals as in FIG. 7 indicate the same or corresponding parts. This torque converter is equipped with a lock-up clutch 20. The taker 1 is attached to the inner circumference of the wheel stator 7a.
0 or integrally formed.

In such a torque converter, the process of assembling the outer race 8 to the inner periphery of the wheel stator 7a is performed by a casting operation as shown in FIGS. 4 and 5. Figures 4 and 5 are schematic vertical cross-sectional views of the casting machine;
31 is a mold for forming a wheel stator. A cooling center guide 32 is provided at the center of one of the molds 31 .

The center guide 32 is a cylindrical body sized to fit on the inner circumference of the outer race 8, and has a structure in which cooling water flows. Outer lace 8 is SCM415.4
After being formed by forging, turning, etc. using a material such as No. 20, the surface is hardened by carburizing and quenching. First, as shown in FIG. 4, the center guide 32 of the mold 31
Set outer lace 8 on. Then, as shown in FIG. 5, the molds 31 are aligned and molten aluminum 33 is injected under pressure. In this way, an integral body of the wheel stator 7a and the outer race 8 as shown in FIG. 6 is obtained. Finishing processes such as deburring, turning, and balance correction are applied to this integrated object.

In such a casting operation, the inner peripheral part of the outer race 8, that is, the part where surface hardness is required, is cooled by the center guide 32, so that the hardness does not decrease. Therefore, unlike the conventional example, it is not necessary to perform induction hardening after casting, and the effort of heat treatment is saved compared to the conventional example. Moreover, although induction hardening can only be performed individually, carburizing and hardening can be performed in large quantities in 10 parts, further simplifying the heat treatment process. Furthermore, there is a process of machining the inner periphery of the wheel stator 7a and the outer periphery of the outer race 8 shown in the conventional example, and
The process of press-fitting is omitted.

In this way, the heat treatment process and, in turn, the manufacturing process are simplified, so that the cost can be reduced. Furthermore, if the outer race 8 is cast into a structure in which the retainer 10 is integrally formed with the foil stator 7a as shown in FIG. 1 and then subjected to induction hardening as in the conventional example, the retainer 10 will melt. Therefore, in the conventional method, a structure in which the retainer 10 is integrally formed with the foil stator 7a cannot be adopted. However, according to the method of the present invention, there is no need for heat treatment after casting, so the wheel stator 7
A structure in which the retainer 10 is integrally formed with the wheel stator 7a can also be adopted, increasing the degree of freedom in the structure of the wheel stator 7a and the retainers 9 and 10.

(Effects of the Invention) As described above, according to the assembly method of the present invention, the outer race 8, which has been subjected to surface hardening heat treatment in advance, is set in the die-cast mold 31 for forming a foil stator equipped with the center guide 32 for cooling. , Since the inner peripheral part of the outer race 8 is cooled by the center guide 32 during casting,
In the casting operation, it is possible to prevent the hardness of the inner peripheral portion of the outer race 8, that is, the portion where surface hardness is required, from decreasing. This eliminates the need for induction hardening after casting as in the conventional example, and saves the effort of heat treatment compared to the conventional example. Furthermore, by performing carburizing and quenching as the surface hardening treatment, the time and effort required for heat treatment can be further simplified. Furthermore, the process of machining the inner periphery of the wheel stator 7a and the outer periphery of the outer race 8 and the process of press-fitting the outer race 8 into the wheel stator 7a, which are shown in the conventional example, can be omitted. Therefore, heat treatment processing and even manufacturing can be simplified.
Cost reduction can be achieved. Furthermore, since heat treatment after casting is not required, a structure in which the retainer 10 is integrally formed with the foil stator 7a can be adopted, and the degree of freedom in the structure of the foil stator 7a and the retainers 9 and 10 can be increased.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a torque converter manufactured using the assembly method of the present invention, FIG. 2 is a perspective view showing an outer race, and FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. Figures 4 and 5 are longitudinal cross-sectional schematic diagrams showing the casting machine used in the method of the present invention, Figure 6 is a diagram showing the integral body of the foil stator and outer race obtained in the casting operation, and Figure 7 is FIG. 1 is a vertical cross-sectional view showing a conventional general torque converter. 7a・
...Wheel stator, 8...Outer race 9.10
−=Retainer patent applicant Daikin Seisakusho Co., Ltd.

Claims (1)

[Claims] In the method of casting and assembling an outer race on the inner periphery of the wheel stator of a torque converter, an outer race that has been subjected to surface hardening heat treatment in advance is set in a die-casting mold for forming a wheel stator equipped with a center guide for cooling. A method for assembling a wheel stator and an outer race of a torque converter, characterized in that a decrease in hardness of the outer race during casting is prevented by cooling the inner periphery of the outer race with a center guide.