JPS6246064A - Toothed pulley made of sheet metal and method of manufacture thereof - Google Patents

Abstract

PURPOSE:To aim at increasing the rigidity of a pulley against the tension of a belt, by providing reinforcing members on the rear side of at least either one of tooth bottom sections and tooth flank sections. CONSTITUTION:A pulley has an integrally formed sheet metal cup-like peripheral wall section which is formed therein with a pulley tooth section 4, tooth bottom sections 5, tooth flank sections 19 and a plurality of reinforcing members 21, 22 that are projected from the inner surface of at least either one of the tooth bottom sections and the tooth flank sections and extend in a direction substantially perpendicular to the axis of the pulley. With the provision of the reinforcing members 22, the wall thickness of the corner sections of the tooth section 4 is increased by 20% in comparison with those of the pulley having no reinforcing members, and therefore, the strength of the pulley may be increased. Further saggings at both shoulder parts 23 of the pulley tooth section are reduced to alloy the pulley tooth section 4 to have a satisfactory shape, and the rigidity of the pulley tooth section 4 is increased. Meanwhile, the reinforcing members 21 increases the rigidity of the toothed pulley against the belt tension.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a toothed pulley made of sheet metal whose tooth profile is reinforced in rigidity against the tension of a toothed belt, and a method for manufacturing the same.
The tooth profile is integrally formed with its reinforcing bar by cold forging.

Conventional technology A method for manufacturing toothed pulleys made of sheet metal was already published in Japanese Patent Application Laid-open No. 5
7-177457, the toothed J pulley described in this publication has a complete tooth shape in which the wall thickness of both shoulders of the pulley crest is extended to about 60% of the thickness of the base plate. There are drawbacks such as: (1) it is difficult to ensure the strength of the heald tension; and (2) the rigidity against the heald tension is insufficient.

Problems to be Solved by the Invention In order to solve the above-mentioned drawbacks (■) and (■) of the prior art, the present applicant first developed a toothed structure in which a plurality of reinforcing bars in the circumferential direction were integrally formed on the inner surface of the pulley teeth at the same time as forming the tooth profile. Although a pulley was proposed (Japanese Patent Application No. 51-119088), the present invention eliminates both or one of the above drawbacks by integrally forming reinforcing bars on the inner surface of the teeth of the pulley teeth. The purpose of the present invention is to provide a toothed pulley and a method for manufacturing the same.

Means for Solving the Problems The pulley of the present invention has at least a pulley tooth portion, a tooth bottom portion, a tooth side portion, and a tooth bottom portion and a tooth side portion on the peripheral wall portion of a cup-shaped body integrally formed with a metal plate. It is characterized by integrally forming a plurality of reinforcing bars in a direction substantially perpendicular to the shaft protruding from one inner surface.

In addition, the method for manufacturing a pulley of the present invention is such that a cup-shaped body having a peripheral wall portion serving as a tooth profile portion of a toothed pulley made of a sheet metal and having a solid lubricant coating formed thereon is provided with peaks and troughs that match the inner shape of the tooth profile portion. a punch having a groove substantially perpendicular to the axis λ1 carved on at least one surface of the trough and the side surface; an upper cylindrical surface into which the peripheral wall fits; and the crest. and a lower mold part in which a valley part, a peak part, and a side part are opposed to each other with a gap smaller than the wall thickness of the peripheral wall part, and a mold part is formed between the upper cylindrical surface and the nuclear mold part. Pressure is applied for one circuit using a die having a conical slope, and when the peripheral wall passes through the conical slope, the pressure in the diametrical direction applied to the peripheral wall by the conical slope causes the peripheral wall to become substantially parallel to the axis on its inner surface. It is characterized in that a plurality of reinforcing bars in a direction perpendicular to each other are formed on the protruding tooth profile.

The plurality of reinforcing bars protruding from the inner surface of the side parts of the pulley teeth reach both shoulder parts of the pulley tooth part, and the wall thickness of both shoulder parts is reduced to about 60% of the thickness of the base plate by cold forging. The stretched and weakened portion is reinforced, thereby improving the tooth profile and increasing the rigidity of the toothed heald against tension.

In addition, a plurality of reinforcing bars protruding from the inner surface of the toothed portion also enhance the rigidity of the pulley against belt tension.

In addition, the reinforcing bars formed on the sides and bottom of the pulley teeth prevent the flow of material in the axial direction during cold forging, thereby minimizing the decrease in wall thickness at the inner corners of the pulley and increasing the rigidity of the pulley. increase.

Example In order to manufacture the toothed pulley of the present invention, first, a steel plate suitable for cold forging is drawn into a cup shape, and then an effective solid lubricant coating treatment is applied to the tooth forming shape, and then the tooth forming shape is formed. Perform processing.

As the solid lubricant coating, a zinc phosphate coating treated with lubrication is most suitable, but other methods such as hot-dip galvanizing or electrolytic galvanizing may also have the same effect. Further, the solid lubricant coating treatment may be performed on the raw iron plate or blank, and in this case, the cost will be lower than in the case of the processing sequence described in ``2''. The blank is first drawn to form a cup-shaped body 3 having a raised bottom I and a peripheral wall 2 in which the pulley teeth are to be formed, as shown in FIG.

Next, the edge of the peripheral wall portion 2 is trimmed, but 1-IJ trimming is not necessarily necessary for forming the tooth profile.

As shown in FIG.
It is about 0.2 mm larger, and the do is 1 larger than the diameter d2 of tooth part 4.
．． Set it so that it is about 2 mm larger.

Next, in order to form the pulley tooth portion 4 and the tooth bottom portion 5 on the peripheral wall portion 2, the cup-shaped body 3 is cold-forged using a punch 6 and a die 7. In order to reduce the friction with the die during cold forging, the cup-shaped body 3 is treated with a phosphate coating, and if a lubrication treatment is applied on top of that to form a metal soap coating on the metal surface, extreme pressure can be achieved. It can maintain and maintain its hot water properties regardless of the conditions.

Punch 〇 has pulley teeth 4 and tooth bottom 5 on the outer peripheral surface of the cylindrical body.
It has a peak portion 8, a valley portion 9, and a side surface portion 10 that match the inner surface shape of the trough portion 9, and a large number of all and 12 are carved in the valley portion 9 and side surface portion 10, respectively, running in a direction perpendicular to the axis. Figure 4a). groove l
L12 is depth 0, 1~0.2 mm, width 0.5~1 m
The cross-sectional shape is appropriately determined, such as triangular, serrated, ladder-shaped, arc-shaped, etc., in consideration of moldability and mold release properties.

The die 7 includes an upper cylindrical surface 13 into which the peripheral wall portion 2 is fitted, a trough portion 14, a peak portion 15, and a side surface portion 6 that are formed below the upper cylindrical surface and conform to the external shape of the pulley tooth portion 4 and the tooth bottom portion 5. The mold part 17 has a circular iW-shaped slope 18 formed between the cylindrical surface 13 and the mold part 17. However, the mold part 17
The gap tl between the opposing peaks and troughs of the punch 6 and the gap t2 at the tooth side portion 19 (FIG. 2) are determined to be approximately 0.5 mm smaller than the wall thickness of the inner wall portion 2.

The lower surface of the punch 6 and the upper surface of the counter punch 20 are shaped to match the top and bottom uneven shapes of the cup-shaped body bottom 1 to prevent lateral displacement.

Next, the process of forming the pulley tooth profile will be described with reference to FIGS. 3 to 7.

First, the force/knob-shaped body 3, which has been treated with the required solid lubricant coating, is placed on the counter punch 20, and the punch 6 is lowered (
Figure 3.4). As a result, the peripheral wall portion 2 and the bottom portion 1 following this
Under the friction-reducing effect of the solid lubricant coating, the outer circumferential portion of the outer peripheral portion is pushed toward the center by the slope 18 and is first preformed into the shape shown in Fig. 41).

As the bunch 6 further descends, the peripheral wall portion 2 is pushed into the gap between the punch 6 and the mold portion 17.

As mentioned above, since the gap lengths tl and t2 are smaller than the wall thickness of the peripheral wall 2, the peripheral wall 2 and the outer peripheral part of the bottom 1 following it are connected to the peaks 8 and troughs 9 of the bunch 6 and the mold part. Due to the squeezing action between the troughs I4 and the peaks 15 of 17, as shown in FIG. lateral part 19 (FIG. 7), and at the same time the material is forced into the groove 11.12, reinforcing bar 21 is formed on the tooth base 5 and on the inner surface of the tooth side I9.
．． 22 is formed to complete the cold forging. Next, when the punch 〇 is pulled up, the cast product is placed in the same position as the punch 〇.
However, since the reinforcing bars 21 and 22 have a small height, the cast product can be easily released from the punch 6.

During the above forging process, the reinforcing bar 22 reduces the flow of +, t It in the part of the pulley teeth 4 near the bottom 1.
The reduction in wall thickness at the corner connecting the teeth 4 and the reinforcing bar 2 is reduced.
The corner wall thickness is increased by approximately 20% compared to the case where the tooth section 2 is not provided, improving the pulley strength.At the same time, due to the reduction in the elongation of the corner section, the effective dimension in the axial direction of the tooth section 4 increases, resulting in improved tooth profile accuracy. becomes good. The reinforcing bar 22 also has both shoulder portions 23 of the pulley teeth.
(FIG. 7) This reduces droop and helps form the pulley tooth portion 4 into a good desired shape, while at the same time increasing the rigidity of the pulley tooth portion 4.

Further, the reinforcing bar 21 increases the rigidity of the toothed pulley against belt tension. Since the effects of each of the reinforcing bars 21 and 22 described above are exhibited independently of each other, it is effective even if only one of them is provided.

If it is difficult to release the reinforcing bars 21, 22 from the punch 6 due to the cross-sectional size and shape, the punch 6 may have a split structure.

Effects of the Invention The sheet metal toothed pulley of the present invention has a reinforcing bar on the back surface of at least one of the tooth bottom part and the tooth side part, so the rigidity against heald tension is increased, and the reinforcing bar is provided on the back face of the tooth side part. This has the effect of improving the shape of the pulley teeth, increasing the effective tooth length, and reducing noise.

Furthermore, since the manufacturing method of the present invention forms the pulley tooth profile by one cold forging, it has the advantage of being able to form a single toothed pulley with good strength and dimensional accuracy with a minimum number of man-hours.

In addition to pulleys for toothed heddles, the present invention is also applicable to items such as clutch drums and clutch hubs, which have a larger axial length relative to a straight line than the pulley, thereby suppressing the axial elongation of the material. It has the effect of being able to hang up, and the reinforcing bars can also be used for oil sump.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a vertical cross-sectional view of a J-cup shaped body, and FIG.
Figures 3, 4, and 5 are vertical cross-sectional views for explaining the cold forging process, Figures 4a and 5a are enlarged vertical cross-sectional views of main parts of Figures 4 and 5, respectively, and Figure 4b is Sectional view taken along line A-A in Figure 4a, No. 6
The figure is a partial plan view for explaining the flow of material during cold forging, and FIG. 7 is a partial perspective view of the pulley of the present invention. 2... Peripheral wall portion 3... Cup-shaped body 4...
・Pulley teeth 5... Tooth bottom 6... Bunch
7... Dice 8... Yamabe
9... Valley part 10... Side part 11.12.
... Groove 13 ... Upper cylindrical surface 14 ... Valley part 15
...Mountain part 16...Side part 17...Mold part 1B...Conical slope 21.22...
Reinforcement pier agent Patent attorney Yuyogi - 2 others Figure 1 Figure 2 Figure 3 Figure 6 I-So Figure 7 Procedural amendment October 2, 1985 []

Claims (2)

[Claims] (1) A peripheral wall of a cup-shaped body integrally formed with a metal plate has a pulley tooth portion, a tooth bottom portion, a tooth side portion, and a shaft protruding from the inner surface of at least one of the tooth bottom portion and the tooth side portion. A toothed pulley made of sheet metal that is integrally formed with multiple reinforcing bars in the direction perpendicular to the direction. (2) A cup-shaped body that has a peripheral wall that becomes the tooth profile of a toothed pulley made of sheet metal and has a solid lubricant coating formed thereon has a peak part, a valley part, a side face part that matches the inner shape of the tooth profile part, and the valley part. a punch having a groove substantially perpendicular to the axis carved on at least one surface of the upper cylindrical surface into which the peripheral wall is fitted, the crests, the valleys and the side surface; On the other hand, a die having a lower mold part in which a valley part, a peak part, and a side part are formed facing each other with a gap smaller than the thickness of the peripheral wall part, and a conical slope formed between the upper cylindrical surface and the mold part. When the peripheral wall passes through the conical slope, the peripheral wall is subjected to diametrical pressure applied to the peripheral wall by the conical slope, thereby causing the peripheral wall to have a plurality of pressure points on its inner surface in a direction substantially perpendicular to the axis. A method for manufacturing a toothed pulley made of sheet metal, characterized in that a reinforcing bar is formed on a protruding tooth profile.