JP3434766B2 - Forming method of cylindrical body end - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an end portion of a cylinder.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 13 (B), as a method for forming a plurality of inlets or outlets 102 on one end of a metal cylinder 101, as shown in FIG. 13 (A). 14 is a method for welding and combining two component parts 103 and 104 by simple press molding at a flange portion 105, and FIG.
A method of forming an inflow port or outflow ports 206 and 207 by inserting a core material into the cylindrical material 201 shown in (A) and sequentially crushing it into 202 to 205 as shown in (B) to (E). It is common. Such a manufacturing method is described in, for example, Jitsukai Sho 60.
No. 121594 and No. 60-137113.

Further, a flat circular metal plate 301 as shown in FIG. 15 (A) is subjected to a press work using a known concave type and convex type, and a work 3 having a truncated cone shape as shown in FIG. 15 (B) is formed.
02, and then the hole 303 as shown in FIG.
And the collar 304 is trimmed, and as shown in FIG. 15 (D), the ends are processed into the small opening 305 and the large opening 306 to form the intermediate member 307. The large opening 306 of the intermediate member 307 is pressed from both sides with a mold not shown to form an intermediate butted portion 308 as shown in FIG. A molding of 310 is disclosed in Japanese Patent Publication No. 56-30084.

[0004]

A catalyst carrier having a large diameter is used in a catalytic converter or the like arranged in the exhaust system of an internal combustion engine in order to improve the purification performance. The ratio of the diameter of the inlet or outlet is large,
For example, it tends to be more than doubled.

When the ratio of the diameter of the general portion to the diameter of the inflow port or the outflow port is large, two component parts are manufactured even if the manufacturing method shown in FIG. 13 can be used. The process and the process of joining and welding these are required, and there is a problem that the process and cost are high and the reliability is poor.

Further, in the manufacturing method shown in FIG.
It can meet the demands of cost reduction and product durability reliability because it can be easily integrally processed and formed from the cylindrical material itself without waste, but as mentioned above, in order to cope with the large diameter ratio, the inlet The crushing process must be performed a plurality of times until the part or the outlet part has a desired diameter or shape, and a heat treatment for softening the work-hardened material is required between the steps. Therefore, in addition to the need for heating equipment and heating process, this manufacturing method cannot cope with a significantly large diameter ratio due to the limit of the process of sequentially crushing the material.

Further, in the manufacturing method shown in FIG.
Large concave and convex presses are required to form the intermediate material 307, which results in a high cost, and since the material is work-hardened by the large plastic deformation caused by the press work, a large press machine is required in the pressing process of the next step. It is difficult to form the branch pipes 309 and 310 by reducing the diameter.

In view of the above, the present invention provides a tubular end portion which can be easily formed even if the number of steps is smaller than the number of conventional steps and the ratio of the diameters of the general portion and the openings such as the inlet or the outlet is large. It is an object of the present invention to provide a molding method of.

[0009]

In order to solve the above-mentioned problems, the first invention according to claim 1 is the end of a metallic cylindrical body.
Section, the perimeter of the cross section is the largest at each axial portion of the cylinder.
Spinning is applied so that the circumference of the cross section of the final shape is approximately the same.
The first step of forming a reduced diameter portion by machining, and then the reduction
Forming multiple openings by crushing part of the diameter from the side
And a second step .

In the present invention, since the end of the tubular body, which is the portion to be molded, can be reduced in diameter at a high reduction rate by the spinning process, the tubular body can be easily compressed by the crushing in the next step. A high opening can be formed. Furthermore, since the diameter can be reduced at a high rate by the spinning process at a stretch, there is almost no work hardening or weakening, and crushing in the next process (plastic processing)
There are few adverse effects and restrictions.

[0011]

Further, according to the present invention, the diameter of the end portion, which is the portion to be processed, of the cylindrical body is reduced by the spinning process, which is the first step, so as to substantially match the circumferential length of the cross section of the final shape. Even if the final shape is complicated, the final shape can be obtained easily and with high accuracy. Moreover, since the spinning process is performed, the reduced diameter portion having the complicated shape can be easily formed.

[0013] The second invention of claim 2, wherein, in the first <br/> invention, in the second step, to close the partially crushed from both sides of the reduced diameter portion, a plurality of openings To form a part.

A third invention according to claim 3 is the above-mentioned first or second invention.
In the second aspect of the invention, the first step is a sequential spinning process by a plurality of passes of the spinning roller.

According to the sequential spinning processing as in the present invention, the larger the number of passes and the smaller the machining amount between passes, the higher the shape accuracy can be obtained, and the larger the machining amount can be dealt with.

[0016] The fourth invention of claim 4, wherein, in any one invention of the first to third, in the first step, mutually and the axis of the axis and the cylindrical body of the reduced diameter portion The reduced diameter portion is formed by concentric or eccentric or inclined.

In the present invention, the reduced diameter portion is formed concentrically, eccentrically or inclined with respect to the cylindrical body in the first step, so that it is concentric with the cylindrical body by crushing in the next step. Alternatively, an eccentric or inclined opening can be easily formed.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described based on the embodiments shown in FIGS.

1 to 8 show a first embodiment.

As an example, as shown in FIG. 1, two small-diameter openings 2 and 3 are formed at one end of a general part 1 having the same diameter as the raw material tube, and both openings 2 and 3 are formed. A closing portion (partitioning portion) 4 is formed between the opening portions 2 and 3, and a grading portion 5 is formed between the closing portion 4 and the general portion 1, and one small-diameter portion is provided at the other end of the general portion 1. A case where the opening 6 is formed and the catalyst converter 8 having the catalyst carrier 7 incorporated in the general portion 1 is manufactured will be described.

FIG. 2 is a diagram for explaining the outline of the molding process of the present invention, in which (A) shows a cylindrical metal straight pipe which is a cylinder (element pipe), and (B) shows an end of the cylinder. The figure of the 1st process which carried out the diameter reduction of the part by spinning processing is shown, and (C) shows the 2nd process of pressing the reduced diameter part to the final shape, and the catalyst carrier 7
Fig. 3 shows a diagram in which the other end is reduced in diameter.

3 to 8 are views for explaining the molding process in more detail.

First, a cylindrical body (base pipe) 1A which is a cylindrical metal straight pipe as shown in FIGS. 2A and 3 is prepared. Figure 3
Then, the diameter R ₁ of the cylindrical body 1A is set to 140 mm, and the plate thickness t
Was 1.5 mm. The cross-sectional shape of the cylindrical body 1A is preferably a circular cross section, but may be a non-circular cross section such as an ellipse, an ellipse, or a polygon. However, the cross section shall be such that spinning processing in the subsequent process is possible.

Next, as a preparation prior to the first step, the shapes formed by the spinning step in the next step, that is, the openings 2 and 3, the closed portion 4 and the modified portion 5 which are the processed portions are formed. The circumferential length of the transverse cross section is calculated by spinning at each part in the pipe axis direction. In this calculation, it is desirable to calculate in many parts over the entire region to be processed (L shown in FIG. 2C and FIG. 8C), but it is necessary to calculate the minimum region required for processing (surface deformation). (Eg, location) may be calculated, and may be arbitrarily determined according to the requirements of easiness of processing and shape accuracy.

In the embodiment shown in FIG.
As shown in (B), an opening ₂ having a diameter R ₂ of 49.2 mm is provided at the end of a cylindrical body (base pipe) _{1 A} having a diameter R ₁ of 140 mm.
3 is formed through the gradual change portion 5, the portion L to be processed is as short as 85 mm, and it does not take much time even if the measurement pitch P is subdivided. The length was calculated. Each pitch P
The perimeter D at is a value as shown in FIG. This value is the perimeter of each part whose diameter is reduced by spinning. The unit of the numerical value of D in the figure is mm.

On the basis of this calculated circumference, as shown in FIG. 2 (B) and FIG. 4, the spinning roller 9 is subjected to the spinning process which is the first step, and the cylindrical body 1A which is the processed portion.
The diameter of the end portion of is reduced to the above calculated value. This spinning process is completed, and the reduced diameter portion 10 as the processed portion is formed in the shape shown in FIGS. 2B and 4.

As described above, when the spinning process is performed based on the peripheral length of each part, the processed part is not formed as a simple tapered part or a coaxial small diameter part, but a complicated axial direction as shown in FIG. It is possible to form a vertical cross-sectional shape, that is, a reduced diameter portion in which expansion and contraction are continuously combined in the axial direction to change.

Generally, if it is attempted to provide a plurality of small-diameter openings and closed portions at the ends of a large-diameter cylindrical body, the intermediate shape thereof will generally have a cross-sectional shape similar to that shown in FIG.

However, when the shape shown in FIG. 4 is processed by conventional press working or insertion into a die, molding cannot be carried out in one step, and a plurality of diameter reducing and expanding operations are alternately repeated. It is necessary to weaken the material and work harden it, and the working limit becomes extremely low. Therefore, a product (container) having a high diameter ratio as in the present embodiment cannot be molded at all by the conventional press processing or insertion processing into a die.

In other words, according to the spinning process as in this embodiment, it is possible to form an arbitrary vertical cross-sectional shape at a stretch while matching the peripheral lengths of the horizontal cross-sections and to obtain a high shrinkage ratio in the final shape. That is, the limit of diameter reduction processing by conventional press processing and die processing is 20% or more.
It is possible to obtain a diameter reduction ratio far exceeding the above. Further, according to the spinning process as in this embodiment, there is almost no work hardening and weakening, so that there is no adverse effect or restriction on the plastic working due to the crushing in the next step.

In the spinning process, the cylindrical body 1A is fixed without rotating and a plurality of spinning rollers 9 are used.
It is desirable to move the cylinder 1A in the radial direction and the cylinder 1A in the axial direction while revolving the cylinder. However, the cylinder 1A is rotated around its axis and the spinning roller 9 is rotated without revolving. It is also possible to use a method of moving the tubular body 1A in the radial direction and the axial direction of the tubular body 1A.

Further, with respect to the relative movement of the cylindrical body 1A and the spinning roller 9 in the axial direction of the cylindrical body, either one or both may be moved. Further, the number of reciprocations in the axial direction (the number of passes) may be once or plural times. In the sequential spinning process, the larger the number of passes and the smaller the machining amount between passes, the higher the shape accuracy can be obtained and the larger the machining amount can be handled.

Next, as a second step, the opposed parts on both sides in the radial direction at the end 11 of the reduced diameter portion 10 which has been reduced in diameter by the above spinning process are pressed in the centripetal direction to be crushed and mutually Contact. That is, the pressing dies 13 and 14 having the surface 12 shown by cross-hatching in FIG.
As shown in FIG. 5B, the two pressing dies 13 and 14 are arranged so as to face each other, and the driving means (not shown) drives the arrows X and Y shown in FIG. 5B.
Moving in the direction, the opposing parts of the end 11 are crushed from both sides to form a flat shape, and the flat parts 15 and 16 are brought into contact with each other as shown in FIG. 5 (B). As a result, the closed portion 4 formed by the flat portions 15 and 16 at the end of the tubular body 1A (general portion 1),
The final shape is obtained with two openings 2, 3 located on either side of the closure 4.

The pressing directions X and Y of the pressing dies 13 and 14 are
It is desirable that the direction is orthogonal to the axis of the reduced diameter portion 10.

Instead of the pressing dies 13 and 14 as described above, a die may be inserted from the left side of FIG. 4 to obtain the shape as shown in FIG. In addition, the crushing tool and method in the second step are arbitrary, and well-known construction methods can be appropriately applied.

The molding of one end is completed as described above, but as in the embodiment of FIG. 1, the catalyst carrier 7 is incorporated in the general part 1 and one small-diameter opening 6 is formed at the other end. In order to form 8, after the second step described above, as shown in FIG. 6, from the end of the other end 17 of the general part 1 (on the right side in FIG. 6), the catalyst carrier 7 is formed.
Then, as shown in FIG. 7, the other end portion 17 is subjected to the variable diameter reduction and contraction, and the other end portion 17 is formed into the variable diameter portion 6a and the small diameter opening portion 6. This diameter reducing method is performed by a well-known appropriate processing method such as spinning processing or die processing.

FIG. 9 shows a second embodiment.

The second embodiment is an example in which the axes of the openings 2 and 3 in the first embodiment are eccentric with respect to the axis of the general portion 1.

In this embodiment, during the spinning process of the first step in the first embodiment, the diameter-reduced portion 10 is formed as shown in FIG.
As shown in (A), the diameter reduction part 10 is molded so that the axis O _{2 of the} diameter reduction part 10 is eccentric with respect to the axis O ₁ of the general part 1, and the eccentric diameter reduction is performed in the second step. A part of the end portion of the portion 10 is flattened by being crushed as in the first embodiment. As a result of this flattening, as shown in FIG. 9 (B), openings 2 and 3 and a closing portion 4 which are eccentric to the axial center O ₁ of the general portion 1 in the F direction are formed.

FIG. 10 shows a third embodiment.

The third embodiment is an example in which the axes of the openings 2 and 3 in the first embodiment are inclined with respect to the axes of the general portion 1.

In this embodiment, during the spinning process of the first step in the first embodiment, as shown in FIG. 10 (A), the reduced diameter portion 10 has a shaft center O ₃ whose axis is the axis of the general portion 1. Molded so as to be inclined with respect to the core O ₁ , and in the second step, a part of the end of the eccentric reduced diameter portion 10 is crushed and flattened as in the first embodiment. Is. This flat, as shown in FIG. 10 (B), general portion 1 of the axis O ₁ opening 2, 3 and the flat portion 4 having a shaft center O ₃ which is inclined twisted relationship with is formed .

Further, the other end portions of the second and third embodiments are also formed in the modified portion 6a and the small-diameter opening portion 6 after the second step as in the first embodiment.

The number of the openings 2 and 3 is not limited to two as described above, and may be more. For example, as shown in the fourth embodiment of FIG. 11, three openings 2
2, 23, 23a, or four openings 32, 33, 33a, 3 as shown in the fifth embodiment of FIG.
It may be 3b. Further, in the embodiment shown in FIGS. 1 to 10, the member between the openings 2 and 3 is flattened and closed, but the present invention is not limited to such a flattening work, and is shown in FIG. So that the openings 22, 23, 23a
The member 24 between them is brought close to each other in a non-flat state to form a partition portion, or as shown in FIG. 12, openings 32, 33, 33a,
The members 34 between the portions 33b may be separated from each other by a large distance and may be opposed to each other to form a partition portion.

In the embodiment shown in FIGS. 11 and 12, after the diameter reduction by the spinning process shown in FIGS. 2B and 4 in the first embodiment, as shown in FIGS. , A die 25 arranged outside the reduced diameter portion,
35 in the direction of the arrow Z to crush the reduced diameter portion from the side surface by a desired amount to form the openings 22, 23, 23a and the opening 3.
2, 33, 33a and 33b are molded. In addition, the cross-sectional shape of each opening is arbitrary and may be different from each other.

Although each of the above embodiments is an example applied to molding of a catalytic converter, the present invention can be applied to molding of the other end without the opening 6 or molding of other containers. However, the present invention is not limited to the above applications and examples.

[0047]

As described above, according to the invention described in claim 1, a plurality of openings are provided at the end of the tubular body, the number of steps is smaller than that of the conventional molding method, and the cost is low. It can be molded by increasing the diameter reduction ratio with respect to the diameter of the cylindrical body.

[0048] Further, the final shape even in a complicated shape,
The final shape can be easily obtained only by crushing in the next step.

According to the second aspect of the invention, it is possible to further form a cylindrical end portion in which a plurality of openings are closed.

According to the third aspect of the present invention, it is possible to obtain a high shape accuracy and to cope with a large diameter reduction processing amount.

Further, according to the invention described in claim 4 , further, it is possible to easily form not only the concentric cylinder but also the eccentric or inclined opening with respect to the cylindrical body.

[Brief description of drawings]

1 shows a product molded according to the invention,
(A) is an inclined view, (B) is a side sectional view of (A), and (C) is a left side view of (B).

2A and 2B show a molding process of the present invention, in which FIG. 2A is a view showing a cylindrical body which is a raw pipe, FIG. 2B is a view in which a diameter is reduced by a spinning process which is a first process, and FIG. [FIG. 3] is a view formed by a crushing process which is a second step, in which (a) is a side sectional view and (b) is a left side view of (a).

FIG. 3 is a side cross-sectional view of a tubular body that is a raw tube applied when carrying out the molding method of the present invention.

FIG. 4 is a side sectional view in which the diameter of the cylindrical body of FIG. 3 is reduced by a spinning process which is a first step.

5A and 5B are diagrams in which the reduced diameter portion of FIG. 4 is formed by crushing which is a second step, FIG. 5A is a side sectional view, and FIG. 5B is a left side view of FIG.

6 is a side sectional view of the molded article of FIG. 5 fitted with a catalyst carrier.

FIG. 7 is a view in which the other end is reduced in diameter from the state of FIG.

8A and 8B are views for explaining the diameter-reducing circumference of each part when the diameter is reduced by the spinning process in the first step, where FIG. 8A is a side view showing the dimensions of the final shape, and FIG. FIG. 3C is a left side view of FIG. 3C, and FIG. 6C is a view showing respective dimensions when the diameter is reduced with respect to the final shape of FIGS.

FIG. 9 shows a second embodiment in which the opening is eccentrically formed with respect to the cylindrical body in the present invention, and (A) is a view in which the diameter is reduced by the spinning process which is the first step, (B) is the figure which was shape | molded by the crushing process which is the 2nd process, (a) is a sectional side view, (b) is a left side view of (a).

FIG. 10 shows a third embodiment of the present invention in which the opening is inclined with respect to the tubular body, and FIG. 10A is a view in which the diameter is reduced by the spinning process which is the first step, B)
3A and 3B are views formed by the crushing process of the second step, in which (a) is a side sectional view and (b) is a left side view of (a).

FIG. 11 is a view showing the fourth embodiment of the present invention and seen from the opening side.

FIG. 12 is a view showing the fifth embodiment of the present invention and seen from the opening side.

13A and 13B show a first conventional technique, in which FIG. 13A is a perspective view showing components, and FIG. 13B is a perspective view of a product.

14A to 14E are diagrams showing steps of a second conventional technique.

15A to 15E are views showing steps of a third conventional technique.

[Explanation of symbols]

1A cylinder A few openings 4 Block 10 Reduced diameter part

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B21D 41/04 B21C 37/15 F01N 3/28

Claims (4)

(57) [Claims] 1. The diameter of the end portion of the metal tubular body is reduced by spinning so that the circumferential length of the cross section at each axial portion of the tubular body is substantially equal to the circumferential length of the cross section of the final shape. Forming the end portion of the tubular body, and a second step of forming a plurality of openings by crushing a part of the reduced diameter portion from the side surface. Method. 2. A second step, to close the partially crushed from both sides of the reduced diameter portion, the molding method of the cylindrical body end of claim 1 Symbol placement to form a plurality of openings. Wherein the first step is, claim 1 also is a sequential spinning process by several passes of the spinning roller
Is a method for forming an end portion of a tubular body according to 2 . 4. The reduced diameter portion is formed in the first step by concentrically, eccentrically or slanting the axial center of the reduced diameter portion and the axial center of the cylindrical body with each other. 4. The method for forming an end portion of a tubular body according to any one of 3 above.