JPH07275980A - Production of pulley of sheet metal - Google Patents

Abstract

PURPOSE:To form a cuplike recessing part without drawing in reverse in a producing method for a pulley of sheet metal having the cuplike recessing part for attaching a bearing. CONSTITUTION:This production consists of a drawing process to form a hollowed hemispheric pre-recessing part and a flange part of a flat sheet metal blank, a recessing part finishing process to finish the pre-recessing part into a cup like recessing part being able to fit with a bearing, a drum wall forming process to bend a flange-like part 12 to the recessing direction of the cup-like recessing part and to form it into a drum wall for winding a belt, and a receiving part forming process to form an opening with a prescribed diameter on the central part of the bottom wall of the cup-like recessing part and to provide an inner flange-like receiving part 24 surrounding the opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a sheet-metal pulley having a cup-shaped recess for mounting a bearing, and a belt wall for surrounding the cup-shaped recess.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 1-44420 discloses a conventional example. A method of manufacturing the sheet metal pulley disclosed in this patent publication will be described with reference to FIGS.

First, a cup-shaped material 100 shown in FIG. 10 is formed by subjecting a flat plate-shaped material to drawing. This cup-shaped material 100 has a flat substrate portion 1.
A small-diameter cylindrical portion 121 is continuously provided on the outer peripheral portion of 10, and an inclined step portion 122 is continuously provided to the small-diameter cylindrical portion 121.
A large-diameter cylindrical portion 123 is connected to 22. The cup-shaped material 100 of FIG. 10 is transferred to the reverse drawing step,
As shown in FIG. 1, the substrate 110 and the small-diameter cylindrical portion 121 are reverse-throttled so that they are concentrically projected into the space S surrounded by the large-diameter cylindrical portion 123. Coarse material 200 formed in this way
Then, various processing steps are performed to form the poly-V grooved material 300 shown in FIG. The material 300 with a poly V groove is provided with a cup-shaped recessed portion 310 capable of fitting with a bearing, which is a bearing, and a body wall 320 for belting provided with a poly V groove 321 and an ear portion 322. There is. Then, as shown in FIG. 12, a hole is bored in the central portion of the bottom wall of the cup-shaped recess 310, and an inner flange of a desired width is formed around the opening 312 having a predetermined diameter formed by the hole. The receiving portion 313 is formed. The receiving portion 313 corresponds to the portion that receives the bearing fitted in the cup-shaped recessed portion 310. Reference numeral 314 indicates a waste material generated by punching holes.

[0004]

In the conventional method for manufacturing a pulley made of sheet metal, the substrate portion 110 of the cup-shaped material 100 is used.
And the small-diameter cylindrical portion 121 are reverse-throttled and the rough material 2 of FIG.
In the step of forming 00, the base plate portion 110 and the small diameter tubular portion 121 after reverse drawing must be finished with sufficient accuracy so that they can be fitted into the bearing. However,
The reverse diaphragm requires a long time, but has a problem that it is difficult to obtain high accuracy. Further, in the conventional method of manufacturing a pulley made of sheet metal,
Since the cup-shaped recessed portion 310 provided in the poly-V grooved material 300 of FIG. 12 is punched to form an opening of a predetermined diameter in the bottom wall to accurately finish the receiving portion 313, the procedure is adopted. There is a problem that a waste material 314 having the same diameter as that of the opening 312 formed by drilling is generated and it is difficult to reduce material loss.

The present invention has been made in view of the above problems, and it is difficult to obtain high precision for forming a cup-shaped recessed portion capable of fitting with a bearing, despite the length of processing time. An object of the present invention is to provide a method for manufacturing a sheet metal pulley that does not require reverse drawing. Further, according to the present invention, a hole is formed in order to provide a receiving portion in a cup-shaped recessed portion that can be fitted with a bearing, but the amount of waste material generated due to the hole can be reduced and material loss is easy. It is an object of the present invention to provide a method of manufacturing a sheet metal pulley that can be reduced to

[0006]

According to a first aspect of the present invention, there is provided a method of manufacturing a sheet metal pulley, wherein a hollow hemispherical pre-recessed portion and a periphery of the pre-recessed portion are formed by drawing a flat sheet metal material. And a regular cylindrical peripheral wall continuous with the bottom wall and the peripheral edge of the bottom wall by molding the preliminary recessed portion formed in the drawing step. The cup-shaped recess formed in the recess-finishing process and the recessed-part finishing process that finishes the cup-shaped recessed part that is capable of fitting with the bearing, and the collar-shaped part formed in the drawing process. A body wall forming step of bending in a direction to form a belt wall for surrounding the cup-shaped recess, and forming an opening of a predetermined diameter in the central portion of the bottom wall of the cup-shaped recess and surrounding the opening. A receiving portion forming step of providing an inner collar-shaped receiving portion on the Is that include. Claim 2
A method of manufacturing a sheet metal pulley according to the invention described in claim 1
In the above, the recessed portion finishing step includes a bottom diameter expanding process of expanding the bottom portion of the preliminary recessed portion formed in the drawing step outward to form the bottom wall of the cup-shaped recessed portion, and the receiving portion forming step is performed. The hole forming process for forming a hole in the center of the preliminary recess formed in the drawing process and the opening formed by this hole forming process are performed as the bottom diameter expanding process performed in the recess part finishing process. The receiving part finishing process of finishing the receiving part to a predetermined width by expanding the diameter to a predetermined size is included. According to a third aspect of the present invention, in the method for manufacturing a sheet metal pulley according to the first aspect, in the body wall forming step, the collar-shaped portion formed in the drawing step is replaced with the cup-shaped portion formed in the recessed portion finishing step. The sloped wall forming process of forming an end wall-shaped sloped wall toward the recessed direction of the recessed part, and the vicinity of the outer peripheral portion of the sloped wall formed by the sloped wall forming process are set in the recessed direction of the cup-shaped recessed part. It includes a body wall forming process of forming a cylindrical body wall by bending it toward the outside. According to a fourth aspect of the present invention, there is provided a method of manufacturing a sheet metal pulley according to the third aspect, wherein the body wall forming process is performed in a direction along an axis of a portion near an outer peripheral portion of the inclined wall formed by the inclined wall forming process. The cylindrical body wall is formed by bending the cup-shaped recessed portion toward the recessed direction while applying force.

[0007]

In the method of manufacturing a sheet metal pulley according to the present invention, the cup-shaped recessed portion that can be fitted into the bearing is formed by finishing the preliminary recessed portion formed in the drawing step into a regular cylindrical shape. Therefore, the reverse drawing is not necessary for forming the cup-shaped recess. The above operation is also exhibited by the invention of claim 2, claim 3 or claim 4.

According to the sheet metal pulley manufacturing method of the second aspect of the invention, the receiving portion forming step of providing the receiving portion for receiving the bearing in the cup-shaped concave portion includes the center of the preliminary concave portion formed in the drawing step. The hole forming process for forming a hole in the portion and the opening formed by the hole forming process are expanded by the diameter expansion process to the predetermined size as the bottom diameter expansion process performed in the recessed part finishing process progresses. Since the receiving part finishing process for finishing the part to a predetermined width is included, the size of the waste material generated by the hole forming process becomes smaller than the size of the opening formed by the receiving part finishing process, and the material loss is reduced accordingly. Become.

According to the sheet metal pulley manufacturing method of the fourth aspect of the present invention, the body wall which is thicker than the inclined wall is formed by the body wall forming process. Therefore, even if a thin-walled material, which is a starting material, is used as a starting material, a thin wall material will have a sufficiently large strength, and an ear portion can be formed by slotting, or a grooved processing can be performed on the trunk wall. Go and V
By providing a groove, a poly V groove, or the like, it becomes possible to make a pulley for hanging a V belt or a poly V belt.

[0010]

EXAMPLE A method for manufacturing a sheet metal pulley according to an example of the present invention comprises a drawing step, a recessed part finishing step, a body wall forming step, a receiving part forming step, an ear part forming step, and a poly V groove forming step. The pulley manufactured by this method can be used for an idler or the like as a back pulley. Each step will be described below with reference to the drawings.

(A) Drawing process As shown in the left part of FIG. 1 (a), a flat sheet metal material 10 having a predetermined thickness and outer diameter is placed on a movable lower die 80 and a fixed lower die 81, As in the right part of FIG. 1 (a), drawing is performed by the movable lower mold 80, the fixed lower mold 81, and the inner and outer movable upper molds 82 and 83. By this drawing, as shown in FIG. 1B, the hollow hemispherical preliminary recessed portion 11 and the collar-shaped portion 12 around the preliminary recessed portion 11 are molded. In addition,
A circular plate material made of steel or aluminum is preferably used for the sheet metal material 10.

(B) Recessed Portion Finishing Step This step is a step of finishing the preliminary recessed portion 11 formed in the drawing step into the cup-shaped recessed portion 15 which can be fitted into the bearing. Preliminary recessed portion 11 formed through the drawing process
The material 20 integrally including the collar portion 12 and the collar portion 12 is shown in FIG.
As in the left part, the movable lower mold 85, the fixed lower mold 84, and the movable upper and lower movable molds 86 and 87 are formed by drawing. In this drawing, the pre-recessed portion 11 is continuously provided on the bottom wall 13 and the peripheral portion of the bottom wall 13 by the corner forming surface 84a provided on the fixed lower die 84 as shown in the right part of FIG. A cup-shaped recess 15 having a cylindrical peripheral wall 14 is finished. This step is divided into several steps as necessary, and the rounded shapes of the corner portions of the bottom wall 13 and the peripheral wall 14 are reduced in each step. This step includes a bottom diameter expanding process of pushing the bottom of the preliminary recessed portion 11 outward to form the bottom wall of the cup-shaped recessed portion 15. The material 30A manufactured in the first stage of this process is shown in FIG. 3B, and the material 30A manufactured in the second stage (final stage) of this process is shown in FIG. 3C.
Are shown respectively. However, the illustrated material 30A,
Reference numeral 30 shows a receiving part 24 which will be described later. In addition, this recessed portion finishing step may be performed in one step or in three or more steps.

(C) Body Wall Forming Step In this step, the collar-shaped portion 12 already formed in the drawing step is bent in the direction of the cup-shaped concave portion 15 formed in the concave-portion finishing step, This is a step of forming a belt-hanging body wall surrounding the cup-shaped recessed portion 15. This process is shown in FIGS. The left part of FIG. 4 (a) shows a state in which the material 30 that has undergone the recessed part finishing process is arranged in the fixed lower mold 88, and the right part of FIG. 4 (a) shows the above material by the fixed lower mold 88 and the movable upper mold 89. The flange 40 of the cup-shaped recessed portion 15 is formed in the recessed direction Y of the cup-shaped recessed portion 15 into a curved inclined wall 17 having an end widening shape to form a material 40. As shown in FIG. 4B, the material 40 has a curved inclined wall 17 and a cup-shaped recess 15. The left part of FIG. 5A shows a state in which the material 40 is placed on the fixed lower mold 90, and the right part of FIG. 5A shows the fixed lower mold 90 and the movable upper mold 9.
By forming the curved inclined wall 17 of the material 40 into a corrugated shape without breaking the end-spreading shape by 1, the bulging portion continuous with the cup-shaped recess 15 is formed on the inclined wall 17. 17a, an intermediate portion 17b that is slightly flat to the bulge 17a, and an inclined portion 17c that follows the intermediate portion 17b.
It shows that the material 50 is formed by molding and.
The process described with reference to FIGS. 4A and 5A is an inclined wall forming process. This inclined wall forming process does not necessarily have to be performed in two steps as in the embodiment, and may be performed in only one step if possible. A material 50 manufactured by the inclined wall forming process is shown in FIG. The left part of FIG. 6 shows the pressing roller 94 facing the inclined part 17c of the material 50 provided between the lower rotating mold 92 and the upper rotating mold 93, and the right part of FIG. 6 shows the lower rotating mold. It shows a state where the ear portion forming roller 95 is opposed to the inclined portion 70c of the material 50 provided between the 92 and the upper rotary die 93. Figure 6
From the state of the left part, as shown in the left part of FIG.
4 is pressed against the inclined portion 17c. In this case, the inclined portion 70c is sandwiched between the fixed lower die 92 and the movable upper die 93, and when the inclined portion 70c is pressed by the pressing roller 94 and is bent vertically, a force in the direction along the axis is applied to the inclined portion 70c. I am supposed to join. For this reason, the inclined portion 70c is gradually thickened by the force, and is finally molded into the thickened body wall 18 which is concentric with the cup-shaped recessed portion 15. Further, in parallel with this thickening, the body wall 18 and the inclined wall 1
The outer peripheral portion of the corner formed by 7 and 7 is formed at a substantially right angle as shown in the left part of FIG. Figure 6
The process described in the left part of FIG. 7A and the left part of FIG. In this process, the inclined portion 1 of the inclined wall 17
7c, that is, a portion near the outer peripheral portion of the inclined wall 17 formed by the inclined wall forming process is bent toward the concave direction Y of the cup-shaped concave portion 15 to form a cylindrical body wall 18. As described above, the body wall forming process includes the inclined wall forming process and the body wall forming process. In this embodiment, an ear portion 19 is formed on the body wall 18 formed in the body wall forming step by the ear portion forming step described below.

(D) Ear portion forming step In this step, as shown in the right portion of FIG. 7A, the end portion of the body wall 18 on the base side is slotted by the ear portion forming roller 95, and the ear portion is formed by the processing. The part 19 is formed so as to extend obliquely outward from the end of the body wall 18. Where the body wall 1
7 and the inclined wall 17, the outer peripheral portion of the corner is formed at a substantially right angle as shown in the left portion of FIG. A material shortage is unlikely to occur when the parts are slotted, and the ears 19 are formed in a state in which they extend sufficiently obliquely outward. At the same time, in this step, the ears 21 are also bent and formed at the opposite ends of the ears 19. A material 70 manufactured through this process is shown in FIG.

(E) Poly V Groove Forming Step This step is a step of forming a poly V groove on the body wall 18. In this step, as shown in the left part of FIG. 8A, the material 60 that has undergone the body wall forming step and the ear forming step is sandwiched between the lower rotating mold 96 and the upper rotating mold 97 to form a poly V groove. Laura 9
8 is pressed against the body wall 18 to form a poly V groove 22 as shown in the right portion of FIG. At this time, at the same time the ear 1
9 and 21 are finished in proper shapes. A poly-V grooved pulley A manufactured through this process is shown in FIG.

(F) Receiving Portion Forming Step In the receiving portion forming step, a predetermined diameter shown in the right portion of FIG. 3 (a) and FIGS. 4 to 8 is provided at the center of the bottom wall 13 of the cup-shaped recessed portion 15. Is a step of forming the opening 23 and providing an inner brim-shaped receiving portion 24 having a predetermined width around the opening 23. In this receiving part forming step, the material 20 that has undergone the drawing step described in FIG. 1A is placed in the fixed lower die 99 for punching as shown in the left part of FIG. As shown in the right part of FIG.
A and the movable punching die 99B for hole punching are operated to perform the hole punching process, and the small-diameter opening 23a formed by this hole punching process is used to finish the recessed portion described in the right part of FIG. 3 (a). The receiving part finishing process of finishing the receiving part 24 to have a predetermined width by expanding the diameter to a predetermined size as the bottom part diameter expanding process performed in the process progresses. When the hole punching process and the receiving part finishing process are performed, the small-diameter opening formed by the hole drilling process is expanded in diameter by the receiving part finishing process and finished in the receiving part 24 having a predetermined width. The amount of waste material generated by processing is small, which helps reduce material loss. In addition, in this embodiment, FIG.
As for the right part, the hole punching process is performed.
Movable punching die 99 for punching the depressed portion 11 pressed by
Since the hole is drilled at B, the hole is drilled with high precision. This means that the opening 23a having a small diameter is expanded by the bottom diameter expanding process to accurately expand the diameter to the opening 23 having a predetermined diameter. It is useful for finishing the receiving portion 24 to a predetermined width with high precision. In the embodiment described above, the recessed portion finishing step includes the bottom diameter expanding process of pushing the bottom portion of the preliminary recessed portion 11 formed in the drawing step outward to form the bottom wall 13 of the cup-shaped recessed portion 15. No, in the receiving portion forming step, a hole forming process for forming a hole in the central portion of the preliminary recessed part 1 formed in the drawing process and the small-diameter opening 23a formed by this hole forming process are formed in the recessed part finishing step. The receiving part finishing process of finishing the receiving part 24 to have a predetermined width by expanding the diameter to a predetermined size with the progress of the bottom part diameter expanding process performed in (1) is included. A method of manufacturing such a sheet metal pulley is included in the invention of claim 2.

By the way, when the effect of reducing the amount of waste material generated by the perforating process and reducing the material loss is not expected, the receiving part finishing process for finishing the receiving part 24 to a predetermined width is performed after the recessed part finishing process. Can be performed in the process of. That is, the material 30, which has undergone the recessed portion finishing process,
Since all of 40, 50 and 60 already have the cup-shaped recess 15 capable of fitting with the bearing, the opening 23 having a predetermined diameter is formed in the center of the bottom wall 13 of the cup-shaped recess 15.
It is possible to form the receiving portion 24 having a predetermined width by forming the hole by a hole forming process. The sheet metal pulley manufacturing method in which the receiving portion finishing process is performed at the stage after the recessed portion finishing process is included in the invention of claim 1.

In the above embodiment, the poly V groove forming step can be omitted depending on the type of pulley. That is, in the type of pulley where the body wall hangs a flat belt,
A poly-V groove forming step is not necessary, and in the type of V-belt type pulley having a single V-shaped line, only a single V-groove may be formed instead of forming the poly-V groove. On the other hand, the ear portion 19 does not depend on the method of slotting the body wall 18 with the ear portion forming roller 98 as in the above-described embodiment, but the ear portion having a two-layer structure as shown in FIG. 12 is formed. It is also possible to set it.

FIG. 9 shows a state in which the bearing B is fitted into the cup-shaped recess 15 of the sheet metal pulley A manufactured by the embodiment method, and the bearing B is received by the receiving portion 24. The cup-shaped recess 15 and the bearing B can be fitted to each other by press fitting.

[0020]

According to the invention described in claim 1, claim 2, claim 3 or claim 4, the cup-shaped recessed portion which can be fitted into the bearing is formed without performing the reverse drawing. Therefore, it is possible to manufacture a sheet metal pulley having a cup-shaped recessed portion that is processed with high accuracy in a short processing time.

In the sheet metal pulley manufacturing method according to the second aspect of the present invention, the size of the waste material generated by the hole forming process in the receiving part forming step is equal to the size of the opening formed by the receiving part finishing process. Since it is smaller than the above, the material loss is reduced accordingly, which is economical.

According to the sheet metal pulley manufacturing method of the fourth aspect of the present invention, even if a thin plate material is used as a starting material, a thin wall material can form a body wall having sufficiently high strength. , In addition, forming ears by slotting on the body wall,
It is also possible to form a pulley on which a V-belt or a poly-V belt is hung, by forming a V-groove or a poly-V groove on the body wall by grooving.

[Brief description of drawings]

FIG. 1A is an explanatory diagram of a drawing process. (B) is a partially cutaway perspective view of the material that has undergone the drawing process.

FIG. 2A is an explanatory diagram of a hole punching process. (B) is a partially cutaway perspective view of the material that has been subjected to a hole punching process.

FIG. 3A is an explanatory diagram of a recessed portion finishing process.
(B) is a partially cutaway perspective view of the raw material which has undergone an intermediate stage of the recessed portion finishing process. FIG. 7C is a partially cutaway perspective view of the material that has undergone the recessed portion finishing process.

FIG. 4A is an explanatory diagram of a starting stage of an inclined wall forming process in a body wall forming step. FIG. 7B is a partially cutaway perspective view of the raw material after the beginning stage of the inclined wall forming process in the body wall forming process.

FIG. 5A is an explanatory diagram of an intermediate stage of the inclined wall forming process in the body wall forming step. FIG. 6B is a partially cutaway perspective view of the material that has undergone the intermediate stage of the inclined wall forming process in the body wall forming step.

FIG. 6 is an explanatory diagram of a stage immediately before performing a body wall forming process in the body wall forming process.

FIG. 7A is an explanatory view showing a body wall forming process and an ear portion forming process in the body wall forming process. (B) is a partially cutaway perspective view of the material that has undergone the body wall forming step and the ear portion forming step.

FIG. 8A is an explanatory diagram of a poly V groove forming step.
(B) is a partially cutaway perspective view of the sheet metal pulley.

FIG. 9 is a sectional view of a sheet metal pulley to which a bearing is attached.

FIG. 10 is a partial cross-sectional view of a cup-shaped material manufactured in an intermediate step of a conventional method.

FIG. 11 is a partial cross-sectional view of a rough material manufactured in an intermediate step of a conventional method.

FIG. 12 is a partial cross-sectional view of a poly-V grooved material manufactured in an intermediate step of a conventional method.

[Explanation of symbols]

 10 Sheet Metal Material 11 Preliminary Recessed Part 12 Collar-shaped Part 13 Bottom Wall 14 Circumferential Wall 15 Cup-shaped Recessed Part 17 Inclined Wall 17c Inclined Part (Near the Outer Part of the Inclined Wall) 23 Opening 24 Receiving Part

Claims (4)

[Claims] 1. A drawing step of forming a hollow hemispherical preliminary recessed portion and a collar-shaped portion around the preliminary recessed portion by drawing a flat sheet metal material, and a preliminary formed in the drawing step. By forming the recessed portion, the preliminary recessed portion is formed into a cup-shaped recessed portion having a bottom wall and a regular cylindrical peripheral wall continuous with the peripheral edge of the bottom wall and capable of fitting with a bearing. The collar-shaped part formed in the finishing process and drawing process is bent in the direction of the cup-shaped recess formed in the recessed part finishing process to form a belt wall for surrounding the cup-shaped recess. And a receiving portion forming step of forming an opening having a predetermined diameter in the central portion of the bottom wall of the cup-shaped recessed portion and providing an inner collar-shaped receiving portion around the opening. And a method of manufacturing a sheet metal pulley. 2. The recessed portion finishing step includes a bottom diameter expansion process of expanding a bottom portion of the preliminary recessed portion formed in the drawing step outward to form a bottom wall of the cup-shaped recessed portion, the receiving portion forming step. However, the hole forming process for forming a hole in the center of the preliminary recess formed in the drawing process and the opening formed by this hole forming process are used for the progress of the bottom diameter expansion process performed in the recess part finishing process. The method of manufacturing a sheet metal pulley according to claim 1, further comprising a receiving portion finishing process of finishing the receiving portion to have a predetermined width by expanding the diameter to a predetermined size. 3. The body wall forming step forms the flange-shaped portion formed in the drawing step into a sloped wall having an end widening toward the recessing direction of the cup-shaped recessed portion formed in the recessed portion finishing step. And a body wall forming process for forming a cylindrical body wall by bending a portion in the vicinity of the outer peripheral portion of the sloped wall formed by the sloped wall forming process toward the recessed direction of the cup-shaped recessed portion. The method for manufacturing a sheet metal pulley according to claim 1, further comprising: 4. The body wall forming process bends a portion of the inclined wall formed by the inclined wall forming process in the vicinity of the outer peripheral portion toward a concave direction of the cup-shaped concave portion while applying a force in a direction along an axis. The method for manufacturing a sheet metal pulley according to claim 3, wherein the cylindrical body wall is formed by the above.