JPS5920407B2 - Forming method for plate materials such as drive plates for fluid torque converters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a mounting boss on a plate material such as a drive plate for a fluid torque converter.

More specifically, a substantially hemispherical protrusion is formed on a part of the plate material,
The top of this protrusion is drawn and formed into a concave shape in the opposite direction, and then the side walls of the concave part are forged, so that a mounting boss having a step close to the thickness of the plate can be easily formed with good precision and sufficient strength. This invention relates to a molding method that enables molding.

Figure 5 is a longitudinal sectional view of the main parts of a fluid torque converter used in automatic transmissions of vehicles, including the crankshaft, etc.
The output of the drive shaft 1 is transmitted through the drive plate 2 to the pump 3 fixed to it with bolts 8 to drive it, and drives the turbine 4 through the fluid interposed between the blades 3a and 4a. The turbine 4 drives a driven shaft 5, and the output of the drive shaft 1 is transmitted to the shaft 5, 6 is a stator, and 7 is a starting ring gear.

In the above, the drive plate 2 is fixed to the end of the drive shaft 1 with bolts 9, and has a positioning and locking boss part 2a in the center that tightly fits with the outer diameter part 1a of the end of the drive shaft 1. Conventionally, as shown in Fig. 6, a central shaft hole 2-2 is formed in a disk-shaped substrate 2-1, and mounting holes 2-3 are formed around this. At the same time, in order to form a boss portion 2a perpendicular to the plate surface that fits on the shaft 1 on one side of the central portion, the ring plate 2-4 was formed separately and welded to the substrate 2-1.

In such conventional drive plates, the boss portion is formed by welding a separately molded ring plate, which requires a welding process, which increases the number of parts by one, and requires machining the inner diameter of the boss portion after welding. The number of processes increases due to the joining of the ring plates, the weight increases due to joining the ring plates, the productivity is low and the cost increases due to the above, and the material of the ring plates is unfavorable from a material economic standpoint, leading to high costs. There's a problem.

Therefore, it may be possible to draw the boss part, but
The boss part has a substantially thick stepped part, which is perpendicular to the plate surface, and since it is a power transmission part, it needs to be strong, and it needs to be highly accurate. At present, it is difficult to obtain a sufficient amount by conventional drawing force forming, and therefore, the above-mentioned structure has no choice but to be adopted.

The present inventors have devised the present invention in order to solve the above-mentioned problems in a drive plate for a fluid torque converter.

An object of the present invention is to form a substantially hemispherical protrusion on a part of a plate material, draw the top of this protrusion into a concave shape in the opposite direction, and then press-form the side walls of the concave part to reduce the thickness of the plate. It is an object of the present invention to provide a method for forming a plate material such as a dry plate for a fluid torque converter, in which a ring-shaped mounting boss portion having closely spaced step portions can be easily formed with good precision and while maintaining sufficient strength.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 show the molding method according to the present invention in the order of steps.

A disk-shaped material W made of a steel plate with a predetermined wall thickness and whose outer diameter has been cut to the final size is placed between the upper and lower molds 11 and 12 of the molding device 10. punch 13
and a lower punch 14 having a convex spherical surface 14a, and a substantially hemispherical protrusion W1 is formed in the center of the material W between the punches 13 and 14.

The diameter of this protrusion W1 is set larger than the inner diameter of the boss portion to be molded. This is shown in Figure 1. Next, another molding device 2
The material W is put between the upper and lower molds 21 and 22 of 0, and the upper mold 21
is equipped with an upper punch 23 having a circular protrusion 23a projecting from the top of the protrusion W, i.e., a circular protrusion 23a smaller in diameter than the protrusion, and a female punch 23 is provided around the protrusion 23a of the punch 23 of the upper die 21. Tapered and concave V,. The molding surface has a measuring ring-shaped slope 21a, and the central part of the lower mold 22 has the slope 21a.
A lower punch 24 which has a male tapered slope 24a facing a and a recess 24b corresponding to the protrusion 23a in the middle part.
The peripheral part of the mold matching surface of the lower mold 22 and the peripheral part of the slope 21a of the upper mold are made flat, and the central part of the protrusion of the material W between these is inverted from above to downward in a concave shape between the molds and with a punch. Draw forming is performed to form the concave portion W2, the surrounding ring-shaped wall portion W3, and the oblique peripheral wall W4 around the circumference. At this time, the angle θ between the slopes 21a and 24a with the perpendicular to the mold matching surface is set to 454, for example, and the tissue around the protrusion is pressed and flowed between the slopes 21a and 24a and flows into the peripheral wall W4 and the wall W3. The tissue of the part does not escape with extra resistance and outwards. In other words, push the tissue inward with the slope and press the upper punch 2.
The outer diameter of the protrusion 23a of No. 3 is set to be equal to the inner diameter of the boss portion, and the side wall W3 is formed at a substantially right angle without buckling or the like. This is shown in Figure 2. Furthermore, the material W is put between the soil and the lower molds 31 and 32 of the molding device 30, and the protrusion 33a of the upper punch 33 in the center of the upper mold 31 has the same diameter as the inner diameter of the boss part and one outer diameter part. The angle θ1 of the slope 31a of the upper die 31 is larger than θ, for example, 50, and the slope 34a of the lower punch 34 is also the same, and the inner wall and bottom of the recess 34b form a right angle. The aforementioned concave portion W2,
The side wall W3 and the peripheral wall W4 are finally formed. And in this case,
Since the slopes 31a and 34a have large angles, the peripheral wall W4 is forged. As a result, the structure of this portion W4 and the structure of the wall W3 connected thereto are densified. The connecting top W5 is forged, and the walls W3, W
4, and will be thickened as it becomes densified.
In this way, the structure of the wall becomes denser and thicker, and the wall is formed into the final size and shape as shown in Figure V. This is shown in Figure 3,
As a result of the above, the height is 2.5 mm on a steel plate material with a plate thickness of 3.2 mm.
The boss part was molded. As shown in FIG. 4, a shaft hole W8 is formed in the bottom W2 of the boss W7 of the dry plate material W6 obtained in this way, and a mounting hole W9 is punched in the bottom W2 near the wall W3 of the boss. Fig. 4 is a longitudinal cross-sectional view of the drive plate W6 obtained above installed in the fluid torque converter, and the inner diameter part of the wall W3 is fitted around one circumference of the drive shaft, and the installation is done around the bottom of the recess W2. The drive plate is connected to the pump 3 through the bolts 9 through the holes W, . turbine, 5 is the driven shaft,
6 is a stator, and 7 is a starting gear.

Although the illustrated example has been described above as an example implemented in a drive plate of a fluid torque converter, the present invention is not limited to this. As is clear from the above, according to the present invention, it is possible to integrally mold a drive plate having a mounting boss section consisting of a ring-shaped right-angled wall section for positioning and locking from a single steel plate, and the resulting boss section also has a structure. By increasing the thickness and densification of the drive plate, it is possible to ensure sufficient strength for practical use, as well as to achieve good precision.In addition, as a result of the above, a drive plate can be formed at low cost and efficiently without going through a welding process. Furthermore, the obtained product has many advantages such as being lightweight.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIGS.
The figure is a cross-sectional view explaining the molding method step by step, Figure 4 is a vertical cross-sectional view of the main parts of a fluid torque converter, Figure 5 is a similar diagram of a fluid torque converter using a conventional drive plate, and Figure 6 is a FIG. 3 is an enlarged vertical cross-sectional view of a conventional drive plate.

Claims (1)

[Claims] 1. A step of drawing a part of the plate material into a substantially hemispherical protrusion,
a process of reverse drawing forming the protrusion into a concave shape while pressing the top of the protrusion from the outside inward, and a process of forging the side wall of the concave part while pressing the material from the outside inward. A method for forming a plate material such as a drive plate for a fluid torque converter, characterized by comprising: