JP2000153312A - Method for forming boss part on planar work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the thickness dimension of a boss part over the ceiling value at the time of integrally forming the boss part in the center part of a planar work by ironing method. SOLUTION: By moving a forming roller 4 from the inside of the work W to the outside under an indentation h1 of the roller, metal is collected and a protrusion 5 having a chevron-shaped cross section is annularly formed. (A) The forming roller 4 is once separated from the work W and situated on the outside of the protrusion 5. (B) Next, the forming roller is moved from the outside of the work W toward the inside. Consequently, by gradually making the protrusion 5 rise while furthemore growing it, the sleeve-shaped boss part 6 having a large thickness dimension S is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a boss portion of a plate-shaped work, and more particularly, to a method of forming a sleeve-shaped boss portion at the center of a work, such as when manufacturing a sheet metal pulley from a disk-shaped work. The present invention relates to a method of integrally forming by an ironing method which is one of the processes.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 9-50 / 1993 discloses this type of processing technology.
What is described in 6295 gazette is known. In this conventional technique, as shown in FIG.
The disc-shaped work W1 is constrained by the jig 51 and the holding jig 53 having
By the relative rotation of the workpiece W1 and the relative movement in the axial direction, the peripheral edge F of the workpiece W1 is bent toward the jig 51 by the pressing roller 54, and the peripheral edge F that has been bent first is thereafter shown in FIG. As shown in FIG. Next, the pressing roller 54 is moved toward the center of the work W1 while being pressed against the work W1 to perform a so-called ironing process, and as shown in FIG. The boss B1 is formed by positively gathering the center of the work W1. The following roller 56 is
The work W1 serves to prevent the work W1 itself from being curved due to the ironing.

[0003]

In such a conventional technique, the length (height) of the boss portion B1 to be formed ultimately depends on the concave portion 51a of the jig 51 and the distal end surface of the holding jig 53. Although it depends on the set size between the boss portion 53a and the boss portion B1, until the boss portion B1 reaches the set size, the material drawn by the ironing of the pressing roller 54 moves only in the length direction of the boss portion B1. However, it does not actively move in the thickness direction of the boss portion B1. Therefore, the thickness of the moldable boss B1 depends on the plate thickness t1 of the workpiece W1 as a base material. As a result, if the boss B1 having a larger thickness is to be formed, a nonstandard plate Work W1 serving as a base material of a plate material having a thick dimension or a forged plate material
, Which inevitably leads to a significant cost increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. In particular, a boss having a thickness not less than an upper limit thickness determined by the thickness of a base material can be easily formed. It is an object of the present invention to provide an improved molding method.

[0005]

According to a first aspect of the present invention, a plate-like work closely contacted and supported by a support is pressed against a side surface of the work while rotating the support together with the support, and the thickness of the work itself is reduced. By ironing so as to gather the material at the center of the work while reducing
It is assumed that the method is such that a boss portion is formed integrally with the work at the center of the work.

[0006] As a forward movement of the forming roller, a forming roller having a forming surface inclined at an elevation angle in the working direction is moved outward from the center of the work to reduce the thickness thereof. A step of forming an annular ridge on the inner side of the maximum diameter portion of the work by temporarily bringing the material material outward while reducing the size of the work, and a center portion of the work from the outside of the ridge as the return operation of the forming roller. Moving the forming roller so as to reduce the thickness of the work toward, and moving the raised portion to the center of the work while raising it to form a boss portion. I have.

[0007] The invention described in claim 2 is the first invention.
The angle formed by the forming surface, which is responsible for the main forming, and the work surface on the processing progress side at the time of the forward movement operation and the backward movement operation of the forming roller according to the invention according to the invention, is variably controlled during the processing. And

Further, according to the third aspect of the present invention, the degree of reduction of the workpiece thickness at the time of the backward movement of the forming roller according to the second aspect of the invention is determined by the thickness of the workpiece at the time of the forward movement of the forming roller. Is set to be larger than the degree of decrease.

Therefore, according to the present invention, when the forming roller having the inclined forming surface is moved from the inner portion close to the center of the work to the outside while pressing the work (forward movement), the thickness of the work is reduced. As a result, the material material generated is gradually gathered and raised at a portion corresponding to the inclined molding surface, and grows into an annular raised portion having a substantially mountain-shaped cross section.

At this time, during processing, the angle between the forming surface of the forming roller and the work, that is, the inclination angle of the forming roller, is positively variably controlled during processing, so that the material material is reduced. When the angle is changed so as to be easily gathered at one place, the formation of the raised portion becomes more remarkable.

When the ridge has grown to a certain size, the forming roller is once separated from the work serving as the base material, and then the forming roller is positioned outside the ridge, and then the forming roller is moved to the center of the work. Move inward toward the part (return operation). As a result, the previously formed raised portion is raised toward the center of the work while being reduced in diameter while maintaining the annular shape while being reduced in diameter. It becomes a sleeve-shaped boss part having a good length.

The forming roller used at the time of the backward movement may be the same as or different from the one used at the time of the forward movement. Actively variably control the inclination angle of the forming roller,
When the angle is changed so that the material is easily gathered at one place, the formation of the boss portion due to the growth of the raised portion becomes more remarkable, and the shape of the boss portion can be freely controlled.

[0013] In particular, when the degree of reduction in the plate thickness during the backward movement is made larger than that during the backward movement as in the invention according to the third aspect, the protruding portion that becomes the sleeve-shaped boss portion is provided in the middle. Grow smoothly to the boss without buckling.

[0014]

According to the first aspect of the present invention, the method of forming the boss portion by using the forming roller for forming the boss portion is substantially divided into two steps. Since the thickness is shifted from the outside to the inside, it is possible to obtain, as the thickness dimension of the boss part to be finally formed, a dimension not less than the upper limit thickness dimension determined by the base material plate thickness. As a result, the base material thickness required to obtain a boss portion having a predetermined thickness can be relatively reduced, so that the intended purpose can be achieved even if a plate material of a general standard size is used. Thus, there is an effect that the cost can be reduced as compared with the related art.

According to the second aspect of the invention, the angle of the forming roller is positively variably controlled during the processing, so that, in addition to the same effect as the first aspect of the present invention, the material This has the effect of freely controlling the degree of gathering, the degree of growth of the ridges, and the final required shape of the boss.

Further, according to the third aspect of the present invention,
By making the degree of reduction of the plate thickness during the backward movement of the forming roller greater than that during the forward movement, in addition to the same effect as the invention according to claim 2, the raised portion has a sleeve-like shape. This has the effect of preventing buckling in the process of growing on the boss and improving the molding quality.

[0017]

1 and 2 are views showing a preferred embodiment of the present invention. In particular, FIG. 1 shows the structure of a main part of an ironing apparatus to which the present invention is applied, and FIG. The main part enlarged view is shown, respectively.

As shown in FIG. 1, a disk-shaped work W in which a center hole H is previously formed in a central portion is prepared as a base material.
After positioning the work W on the rotatable mandrel 1 as a support, the work W is pressed and held by the tail stock 2 fitted in the center hole H, and the work W is rotated together with the mandrel 1 and the tail stock 2. . In the vicinity of the mandrel 1, a so-called solo-bang ball-shaped forming roller 4 rotatably supported by an arm 3 is provided, and the forming roller 4 is rotated while the work W is rotating as described above. Is pressed against the workpiece W to perform ironing. Note that the inclination angle of the forming roller 4 together with the arm 3 can be arbitrarily variably adjusted.

At the start of the above-mentioned ironing, as shown in FIG. 1 and FIG. 2A, the forming roller 4 is made to enter a portion of the work W near the tail stock 2 at an inclination angle θ1, and As the forward movement of 4, the forming roller 4 is moved toward the outside, that is, toward the maximum diameter side of the work W under the roller pushing amount h1, so that
The material is gradually moved outward to form a ridge 5 having a mountain-shaped cross section in an annular shape. At this time, the forming surface 4a of the forming roller 4 and the inclination angle θ1 of the forming roller 4 during processing, that is, the elevation angle, are adjusted so that the height h2 of the raised portion caused by so-called flesh-fitting becomes a predetermined size. The angle θ2 between the surface of the workpiece W and the forming surface 4a, which is responsible for the main forming during the forward movement of the forming roller 4, is an acute angle of about 5 to 10 ° at the maximum. And

Next, when the raised portion 5 has grown to a predetermined size, the forming roller 4 is once separated from the work W as shown in FIG. The forming roller 4 is positioned outside the raised portion 5 and is then advanced toward the raised portion 5, and the forming roller 4 is now directed from the outside of the work W to an inner portion near the center of the work W. And move it to another molding surface 4
The protrusion 5 is moved to the inside of the work W while the protrusion 5 is further grown using b.

That is, the forming roller 4 is moved to the inside of the work W under the roller pushing amount h3,
The boss portion 6 having a predetermined thickness S is formed by gradually erecting the boss portion while further growing it. At this time, the roller pushing amount h at the time of the forward movement operation of the forming roller 4 is h.
The relationship between 1 and the roller pushing amount h3 at the time of the backward movement is h3.
> H1, and when this condition is not satisfied, the raised portion 5
May be buckled in the process of changing into the sleeve-shaped boss portion 6. Also, at the time of the returning operation of the forming roller 4, the inclination angle θ3 of the forming roller 4 during the processing is set in order to smoothly raise the raised portion 5 to the boss portion 6.
That is, the angle θ4 between the forming surface 4b and the workpiece W is variably controlled, and, for example, the outer peripheral surface of the finally formed boss 6 is parallel to the axis of the boss 6 (see FIG. 2B). The inclination angle θ3 is controlled so as to gradually increase.

Thus, the boss 6 having a necessary and sufficient thickness S is formed integrally with the work W at the center of the work W.

FIG. 3 shows the relationship between the aforementioned roller pushing amount h3 and the thickness S of the formed boss 6, and FIG. 4 shows the base material thickness t and the thickness S of the formed boss 6. Respectively. As is apparent from FIG. 3, in the above-described embodiment, the so-called thinning of the raw material is performed in two steps during the forward movement and the backward movement of the forming roller 4. Compared with the case, the tendency of the thickness S of the boss portion 6 to increase with respect to the pushing amount h3 of the forming roller 4 is remarkable. As a result, as is apparent from FIG. 4, the thickness S of the boss B1 (see FIG. 5) is about 1.0 to 1.1 times the thickness t1 of the base material plate in the conventional processing method. On the other hand, in the present invention, the thickness S of the boss 6 is enlarged to about 1.2 to 1.25 times the thickness t of the base material.

As described above, according to the present embodiment, the work of moving the raw material is performed in two steps, so that the thickness S of the boss portion 6 becomes the upper limit thickness determined by the base material plate thickness t. It is possible to obtain a thickness greater than the thickness.

[Brief description of the drawings]

FIG. 1 shows a preferred embodiment of the present invention,
FIG. 1 is a configuration explanatory view of a main part of an ironing apparatus to which the present invention is applied.

FIG. 2 is an enlarged sectional view of a main part showing a processing progress in the processing apparatus shown in FIG. 1;

FIG. 3 is a characteristic diagram showing a correlation between a pressing amount of a forming roller and a boss to be formed.

FIG. 4 is a characteristic diagram showing a correlation between a base material plate thickness and a thickness of a formed boss portion.

FIG. 5 is a process explanatory view showing an example of a conventional boss portion forming method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mandrel (support) 2 ... Tail stock 4 ... Forming roller 4a, 4b ... Forming surface 5 ... Protruding part 6 ... Boss h1 ... Roller pushing amount at the time of roller going forward h3 ... Roller pushing amount at the time of roller returning S ... Boss wall thickness

Claims (3)

[Claims] A plate-shaped work closely contacted with a support is pressed together with a forming roller against one side while rotating the support together with the support to reduce the plate thickness of the work itself and bring the material to the center of the work. This is a method in which a boss is formed integrally with the central portion of the work by performing an ironing process so that the boss portion is integrally formed with the work. By moving the forming roller having such an inclined forming surface from the center of the work outward, the material is temporarily moved outward while reducing the thickness of the work, so that the inner part of the work is larger than the largest diameter part. Forming a ring-shaped raised portion on the workpiece, and moving the forming roller from the outside of the raised portion toward the center of the work so as to reduce the thickness of the work as a reciprocating operation of the forming roller, Boss forming method of the plate-shaped workpiece, which comprises the steps of forming a boss portion by standing it while moving the raised portion in the central portion of the workpiece, the. 2. An angle formed between a forming surface, which is responsible for main forming and a work surface, on a processing progress side during a forward movement operation and a backward movement operation of a forming roller is variably controlled during processing. The method for forming a boss portion of a plate-shaped work according to claim 1, wherein 3. The method according to claim 1, wherein the degree of reduction in the thickness of the work during the backward movement of the forming roller is set to be greater than the degree of reduction in the thickness of the work during the forward movement of the forming roller. Item 3. A method for forming a boss portion of a plate-like work according to Item 2.