JPS59179250A - Production of v-pulley by plateworking - Google Patents

Abstract

PURPOSE:To enable manufacture of a V-pulley without decrease in strength owing to a deficiency in wall thickness in the stage of manufacturing the V-pulley by plateworking by subjecting a plate-like blank material to drawing, blanking, hemming, bulging and tight-sticking. CONSTITUTION:A disc-shaped blank 2 consisting of a steel or Al alloy is blanked and is drawn to a pot-like formed article 6 having a bottomed cylindrical shape by means of prescribed pressing dies and a flange part 4 flaring outward at 15-45 deg. angle is formed in the opening. Prescribed trimming dies are opened and the material is subjected to blanking to the flange part 4 of the article 6 so that the circumferential edge part thereof is trimmed. The flange part 4 is further subjected to edge bending to bend the circumferential edge in the flange part 4 to a rib shape to have higher rigidity and strength. The body part is then subjected to bulging to form a curved part 8 projecting outward. A bottom part 22 is projected to the opening side and is tightly stuck double, by which a V-pulley 36 provided with a groove 24 is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a pulley on which a belt is hung and rotated, and in particular a V pulley made of sheet metal, in which the V pulley is mainly manufactured from a plate-shaped material (blank) by press working. Relating to a manufacturing method.

Sheet metal V-pulleys have come to be widely used in automobile-related applications because they are advantageous in terms of weight and manufacturing compared to cast or forged products.

By the way, as a method for manufacturing the sheet metal pulley, a method that roughly follows the following steps has been adopted in the past.

(Drawing process) A predetermined blank is subjected to a drawing process to form a pot-shaped molded product having a flange part at the opening, and the flange part is planned as one full surface of the V-groove (drawing process). (2) Next, the flange part is cut out and its peripheral edge is bent to adjust its shape (outline cutting/edge bending process). ■Then, push a punch from the bottom of the pot-shaped molded product to the flange side and perform reverse re-drawing in the opposite direction to the drawing process in ■, forming a double body near the flange. (reverse redrawing process). ■Then, the double body is pushed outward and is made to face the flange part, ■to form the other full surface of the groove (expanding step). ■Furthermore, a close contact process is performed to bring the double bodies into close contact, and other necessary processes such as punching out the shaft hole are performed to obtain the desired sheet metal polished pulley (close contact process).

In the method according to the steps (1) to (2), the wall thickness decreases considerably during reverse re-drawing. Therefore, the quality of the V-pulley as a product is likely to be disadvantageous in terms of strength due to insufficient wall thickness. On the other hand, in order to compensate for the decrease in wall thickness, the blank must be thicker, resulting in poor moldability.

In addition, after reverse re-drawing, it is difficult to form the groove in one step, so it is necessary to perform expansion processing and further contact processing after reverse re-drawing, and it cannot be denied that the number of steps is large. .

The present invention was made against the background of the above-mentioned circumstances, and its purpose is to minimize the decrease in wall thickness during the manufacturing process of a sheet metal V-pulley. Moreover, it is an object of the present invention to provide a manufacturing method that can reduce the overall number of steps.

In order to achieve such an objective, the present invention includes:
A predetermined blank is drawn to form a pot-shaped molded product having an opening with a flange that expands outward at a predetermined angle, and then the flange is subjected to outline cutting and then bent. After bending the peripheral edge of the flange, the body of the pot-shaped molded product is bulged to form a curved part that protrudes outward, and then,
By protruding the bottom of the bot-shaped molded product toward the opening and applying a close contact process, a V-groove is formed between the flange and the curved portion facing the flange.

As a result, the reverse re-drawing knee and expansion knee contact processing in the conventional manufacturing process will be replaced by bulge forming knee contact processing, which will make it possible to suppress the decrease in wall thickness during processing. It also meant that there were fewer losses overall.

9, in order to clarify the present invention more specifically, a more detailed explanation will be given with reference to drawings showing embodiments.

First, in carrying out the present invention, a disk-shaped blank 2 as shown in FIG. 2(a) is usually prepared by punching out a plate-shaped material. However, the shape of blank 2 is planned to be cut out in the later process, so
It is not necessarily limited to a circular shape, and the blank 2
As for the material, an appropriate metal material can be selected, such as steel, aluminum alloy, etc.

Then, the blank 2 is drawn into a cylindrical shape with a bottom as shown in FIG. A drawing process is performed to form a ball-shaped molded product 6. This drawing process is 2
It can also be done in stages.

Therefore, the bottom surface of the flange portion 4 is the part that should constitute one full surface of the groove, and therefore the pot-shaped molded product 6
The angle θ at which the flange portion 4 is inclined with respect to a plane perpendicular to the center line of is generally selected within the range of about 15 to 45 degrees. Since there is an opportunity to define it well, there is no problem in defining it roughly to some extent in this processing.

Next, a predetermined trimming mold is opened, and as shown in (C), the flange portion 4 of the pot-shaped molded product 6 is subjected to outline cutting, and its peripheral portion is trimmed, and further, as shown in (d), By applying edge bending to the flange portion 4,
The peripheral edge part of the flange part 4 after the outline cutting process is bent into a rib shape to increase the rigidity and strength there. Although the outline cutting process and the edge bending process are separate processes from a process standpoint, it is preferable to perform them at the same time using an appropriate composite type device.

After that, as for the boll-shaped molded product 6 that has gone through the steps (c) and (d), the body of the molded product 6 is subjected to a bulge process to form a curved part that protrudes outward, as shown in (e). 8 is formed. This curved portion 8 will eventually oppose the flange portion 4 and constitute the other full surface of the groove. Therefore, in the above-mentioned bulging process, it is preferable to bulge the body part of the pot-shaped molded product 6 that is relatively close to the flange part 4 to provide a curved part 8. It is preferable to make them protrude facing each other.

In addition, in such bulge processing, the processing itself is not very severe, and the bot-shaped molded product 6
Since it is normal to be accompanied by a decrease in the height of
, localized wall thickness reduction is also less likely to occur.

In order to perform the above-mentioned bulge processing, various known methods can be used, and for example, as shown in FIG. 2, it can be easily performed using rubber. That is, the comb 14 held by the chi I rod 10 and the holding plate 12 is inserted into the inside of the bot-like molded product 6, while the bot-like molded product 6 is held by the bolt 16. The comb 14 is held in the die ring 18 or the like, and the bulge mold 2o presses the comb 14 through the bottom 22 of the bot-shaped molded product 6 to inflate it laterally. 8 is formed. In this way, the deviation that drastically reduces the height of the bot molded product 6 becomes a particular problem in suppressing the decrease in wall thickness.

In addition, rubber ii! ii) There are various methods such as bulge processing using elastic force, and there are also methods other than combs that use fluid pressure such as oil, spuninkrace, etc., and it is okay to adopt an appropriate method from among them. This does not prevent the bulge processing from being performed in two stages or the like.

Then, as shown in FIG. 1(e), the bottom part 22 of the bot-shaped molded product 6 with the curved part 8 formed therein is pushed out toward the opening (in other words, the flange R1t4) by an appropriate means. , the four curved portions 8 are subjected to a close contact process in which they are brought into close contact with each other in a double manner as shown in FIG. A groove 24 is formed in the groove 24. Therefore, the curved portion 8 after the close contact substantially functions as another flange portion facing the flange portion 4.

Such close contact processing can be easily carried out using a mold device as shown in FIG. 3, for example.

That is, the support die 26. and a die 2)) which also serves as a knockout, and a bottom mold 22 of the molded product by an upper mold equipped with an ejection punch 32 and a bending punch 34 while holding the bot-shaped molded product 6 in a lower mold made of a gui ring 30 or the like.
The V-groove 24 is formed by protruding from the flange portion 4 and protruding toward the side of the flange portion 4, and by bringing the curved portion 8 into close contact with the flange portion 4 at a symmetrical angle. be.

The above-mentioned close-contact processing can essentially be understood as a folding process by press bending, or something similar to it, and there is almost no drawing element involved, or even if it does, it is only a small amount. Yes, it is essentially different from reverse re-diaphragm. Therefore, regardless of whether or not the close contact process involves a decrease in wall thickness in a strict sense, it can be said that there is almost no decrease in wall thickness as would be the case when reverse re-drawing is performed. Moreover,
By combining the above-mentioned rounding process and this contacting process, there is no need to insert the process of widening the two-way body part for forming the groove between the two processes.

After forming the outer shape of the target pulley 36 as shown in No. 11m(f) in the above manner, additional processing such as providing a shaft hole in the bottom 22 is performed, and further processing is performed as necessary. Then, a finishing process such as shaching is applied to obtain a sheet metal pulley as a product.

As is clear from the above description, according to the present invention,
Pulleys can be manufactured effectively with fewer man-hours, and the decrease in wall thickness during the processing process can be effectively suppressed, so when the product is made, sufficient wall thickness can be ensured from the viewpoint of strength etc. Therefore, high quality can be guaranteed as a sheet metal V-pulley product.

In fact, V obtained according to the invention from a blank under identical conditions
When comparing the pulley and the V-pulley obtained according to the conventional method, it can be seen that there is a large difference, as shown in FIGS. 4(a) and (1)). Each figure is a cross-sectional photograph of an actual product, mainly in the vicinity of the groove 24, and the thickness measured at each part is represented by a fin. Therefore, in the case of the conventional method (a), there are parts where the wall thickness is quite thin as shown by the symbols * and △, whereas in the case of the method of the present invention shown in 4(b), the entire It can be seen that the thickness is appropriate for the overall thickness, and the thickness distribution is also more uniform.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing specific processing steps of the manufacturing method according to the present invention. Fig. 2 is a partial sectional view showing an example of a suitable device and its processing state for processing basil, and Fig. 3 is a partial cross-sectional view showing an example of a suitable device and its processing state for performing contact processing. FIG. FIG. 4(a) is a partial cross-sectional view of the pulley manufactured by the conventional method, with the measurement results of the wall thickness at each part attached, and FIG. 4(b) is a partial cross-sectional view of the pulley manufactured by the method of the present invention. It is a partial sectional view with the same measurement result added about a pulley. 2 Blank 4: Flange part 6: Pot-shaped molded product 8: Curved part! 4: Rubber 20□i< /L/J type 22
:Bottom 24:V drawing Applicant: Kojima Press Kogyo Co., Ltd. 2I Affairs 1 System 3 Diagram 〕'', 4 Procedures (Method) 1. Indication of the case 1982 Patent Application No. 54682 2. Invention Name of Manufacturing Method for Sheet Metal Layer V-Pulley 3, Relationship with the Amendment Case Name of Patent Applicant: Kojima Press Kogyo Co., Ltd. 4, Agent: June 8, 1982 (Delivery Date: June 28, 1980)
6. Subject of amendment (11 drawings (Fig. 1) Name Manufacturing method of sheet metal ■ pulley 3 Relationship with the case of the person making the amendment Patent applicant name Name Kojima Press Kogyo Co., Ltd. 4, agent (1) Detailed explanation of the invention in the specification column 6, Contents of the amendment ( 1) "After processing" on page 3, line 10 of the specification is corrected to "after processing." (2) "Fig. 2 (a)" on page 5, line 2 of the same specification is changed to "Fig. 1. (a)". (3) On page 6, line 4, "open" is corrected to "using". (4) On page 8, lines 5 and 6, "spinning lace". " is corrected to "spinning lace." (5) From page 9, lines 7 to 8, "with the flange portion 4..." is deleted.

Claims (1)

[Claims] A predetermined blank is drawn to form a pot-shaped molded product having an opening with a flange portion expanding outward at a predetermined angle, and then the flange portion is subjected to an outline cutting process,
After further bending is performed to bend the peripheral edge of the flange, the body of the pot-shaped molded product is bulged to form a curved part that protrudes outward, and then the pot-shaped molded product is formed into a bulge. A sheet metal N characterized in that a groove is formed between the flange part and the curved part facing the flange part by protruding the bottom part of the product toward the opening side and performing close contact processing.
A method of manufacturing a V-pulley.