JP3585547B2 - Manufacturing method of strip with irregular cross section and roll with ridges - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a method for continuously producing a deformed cross-section strip excellent in shape accuracy by roll forming, and a roll with protrusions.
[0002]
[Prior art]
The strip having a plurality of thick sections in the width direction is used as a material for a lead frame, a bearing retainer or the like. This type of deformed strip is conventionally manufactured by a cutting method.
In the cutting method, a thin portion in the plate width direction is continuously cut by a cutting tool, a milling machine, or the like while a metal band is passed in a longitudinal direction, thereby forming a thin portion partitioning between thick portions. However, cutting debris that hinders effective use of resources and maintenance of a favorable working environment are generated, and working efficiency is poor. In addition, burrs, warpage, and the like are generated at the cut end, which may cause a reduction in product quality.
[0003]
As an alternative to the cutting method, Japanese Patent Publication No. 53-27234 introduces a method of manufacturing a strip with an irregular cross-section by using a mold having a ridge or a recess gradually widening from the tip. ing. In this method, a metal strip to be rolled is fed between a reciprocating flat roll and a mold, and then the metal strip is pressed while reciprocating the flat roll, thereby forming a stepped portion following the cross-sectional shape of the mold. Is attached to the metal strip. This method is of a batch type in which molding is performed intermittently, and therefore has low productivity. Also, preparing a large number of expensive dies corresponding to various target irregular cross-sectional shapes causes an increase in manufacturing cost. In addition, it is difficult to simultaneously manufacture a plurality of strips having the same shape and different shapes, and it is difficult to mount them on a mass production system.
As a method for solving such a drawback, a method of manufacturing a strip having a deformed cross section by roll forming is introduced in Japanese Patent Publication No. 1-59401, Japanese Patent Application Laid-Open No. 1-297701, and the like.
[0004]
In Japanese Patent Publication No. 1-59401, a strip with an irregular cross section is manufactured in the process shown in FIG. First, feeding the metal strip S with a rectangular cross-section between the grooved roll 1a and the flat roll 1b, rolling the metal strip S of the portion S ₁ of the product thin portion (Fig. 1a). At this time, the portion to be the product thickness portion, the metal strip S is buckled and deformed into the groove of the grooved roll 1a, the curved portion S ₂ is formed. Then, the metal strip S with a pair of flat rolls 2a, passed during 2b, the upper and lower surfaces of the curved portion S ₂ is rolled to become parallel, to form a thick portion S ₃ (Fig. 1b). Thereafter, the metal strip S is rolled into a product shape using the finished grooved roll 3a and the flat roll 3b (FIG. 1c). At this time, since the groove of a shape corresponding to the irregular cross-sectional shape of the target finish is formed in the circumferential direction of the grooved roll 3a, the thick portion S ₃ along the roll profile of the finishing grooved rolls 3a molded, the thick portion S ₄ having a target shape.
[0005]
In Japanese Unexamined Patent Application Publication No. 1-297701, a strip having a modified cross section is manufactured by the steps shown in FIG. First, the metal strip S is passed between the grooved roll 4b and the ridged roll 4a and rolled (FIG. 2a). The grooved roll 4b is formed with a plurality of grooves extending in the circumferential direction at a predetermined curvature in the axial direction. The ridged roll 4a has a plurality of ridges extending in the circumferential direction and having a predetermined curvature at positions corresponding to the grooves of the grooved roll 4b . After passing between the grooved roll 4b and ridges with roll 4a are curved portion S ₂ having a predetermined curvature is formed on the metal strip S. Then, the metal strip S with a pair of flat rolls 5a, passed during 5b, the upper and lower surfaces of the curved portion S ₂ is rolled to become parallel, to form a thick portion S ₃ (Fig. 2b). Thereafter, the metal strip S is rolled into a product shape by using the finished ridged roll 6a and the flat roll 6b ( FIG. 2C ).
[0006]
[Problems to be solved by the invention]
In the conventional roll forming method, in either of the methods shown in FIGS. 1 and 2, (1) a step of rolling only a thin portion to buckle and deform a thick portion, or a process of bending and rolling a thin portion, and (2) a seat. At least three steps are required: a step of rolling a bent thick-walled portion or a curved-rolled thin-walled portion until the upper and lower surfaces become parallel, and (3) a step of finish rolling to a product shape. The large number of steps necessitates preparing a large number of rolls of a plurality of types to be used in each step, and is a bottleneck when improving productivity.
Also, when manufacturing a strip with a modified cross-section by a conventional roll forming method, a step portion having a greatly different inclination angle between a thick portion and a thin portion is likely to be formed. Moreover, each thick portion did not match the depth of the recessed portion of the grooved roll or the ridged roll, and had different plate thicknesses.
[0007]
The low shape accuracy causes a decrease in reliability when the obtained deformed cross-section strip is used as a product. For example, when slitting a strip with an irregular cross section to cut out a single or a plurality of irregular cross sections, the inclination angle of the step section on both sides of the thin section and the thickness of the thick section are not the same. The decrease in dimensional accuracy of the thin portion and the groove section defined by the step portions on both sides of the thin portion directly leads to a reduction in product value. Specifically, in a bearing retainer made from this irregular cross-section strip, the dimensional accuracy of the grooves is different, so that smooth rolling of the bearing is hindered and the performance of the bearing itself is reduced.
The present invention has been devised in order to solve such a problem. By using a ridged roll having a profile designed so that the metal flow in each thick portion is made uniform, the thickness of each roll is increased. It is an object of the present invention to obtain a deformed cross-section plate material having good shape accuracy with a constant inclination angle of a step portion without causing a shortage in a meat portion.
[0008]
[Means for Solving the Problems]
In order to achieve the object, the method for manufacturing a strip material of irregular shape according to the present invention is a roll forming method using a flat roll and a ridged roll having a plurality of ridges formed through a plurality of grooves in the roll axis direction. When manufacturing a strip with a modified cross section , a ridge for a discard groove is formed on the outer side in the roll axis direction of a groove forming a thick part of the product, and the ridge for the discard groove is formed. The groove is formed so that the ratio between the cross-sectional area of the groove-shaped portion forming the meat portion and the integrated value of 断面 of the cross-sectional area of each of the ridges on both sides of the groove-shaped portion is constant at each product thick portion. Using a ridged roll provided with a ridge and a ridge, a metal strip at least equal to the distance between the disposal groove ridges on both sides is passed between the ridged roll and the flat roll. It is characterized by being plated.
The ridged roll used in this method has a discard groove ridge formed on the outer side in the roll axis direction of the groove portion forming the product thick portion, and includes the discard groove ridge. The ratio between the cross-sectional area of the groove portion forming the thick portion and the integrated value of 1/2 of the cross-sectional area of each of the ridge portions on both sides of the groove portion is constant at each product thick portion. A plurality of ridges are provided along a roll axis direction via a plurality of grooves.
[0009]
[Action]
The present inventors investigated the effect of the roll profile on the product shape when producing a profiled cross-section strip by roll forming. Then, it was found that when a strip material having a plurality of thick sections in the sheet width direction was roll-formed at once, the shape accuracy was improved. For example, as shown in FIG. 3, the ridged roll 10 provided with a plurality of ridges 11, 12, 13 in the axial direction at intervals corresponding to the target thin portion is opposed to the flat roll 20. The metal strip S passing between the rolls 10 and 20, the central thick portion _{S 11, S 12} and ends the thick portion _{S 21, S 22} are formed, the thick portion _{S 11, S 12,} during the S _{21, S 22} becomes thin part _{S 31, S 32, S 33} .
However, the modified cross-section strip manufactured by this method has a different slope angle for each step. At the step located at the center, a step having the same inclination angle as the inclination angles θ ₃ and θ ₄ of the grooved roll 10 is formed in the metal strip S, but at the step located at both ends, a groove is formed. The inclination angles θ ₁ ′, θ ₂ ′, θ ₅ ′, and θ ₆ ′ tend to be larger than the inclination angles θ ₁ , θ ₂ , θ ₅ , and θ _{6 of the} roll 10. The end thick portions S ₂₁ and S ₂₂ are also thinner than the center thick portions S ₁₁ and S ₁₂ .
[0010]
The increase in the inclination angle and the insufficient thickness of the end thick portions S ₂₁ and S ₂₂ are caused by the outward metal flow in the width direction that occurs because both ends of the metal strip S are open free ends. That is, in the groove between and 12 and 13 between the ridges 11 and 12, is filled with the groove space by the metal flow from the thin part _{S 31, S 32, S 33} , the central thick portion _S 11, S ₁₂ are formed along the roll profile. On the other hand, at the end in the plate width direction, the influence of the metal flow flowing in one side direction is large, and this appears as an increase in the inclination angles θ ₁ ′ and θ ₆ ′ and a lack of thickness at the end thick portions S ₂₁ and S _22. . In addition, in portions where the metal flows on the left and right are different, the inclination angles θ ₂ ′ and θ ₅ ′ are large at the step portion where the material is less filled. Therefore, if the metal flow generated at both ends in the plate width direction can be regulated, the increase in the inclination angle and the lack of the thickness of the end thick portions S ₂₁ and S ₂₂ can be solved. Therefore, the present inventors have further investigated and studied the effect of the roll profile on the shape accuracy of the irregularly shaped cross-section strip, which is a product, and found that the metal flow generated at the time of rolling is reduced to P ₃₁ , P ₃₂ , different it was found by the cross-sectional area ratio of P ₃₃ and the gap portion. Also, theoretically, the effect of the cross-sectional area ratio on the metal flow is confirmed.
[0011]
That is, if the cross-sectional area ratios are different, the portion with a high metal flow fills the gap before the portion with a low metal flow, so that the rolling is selectively performed in the gap of the grooved roll. On the other hand, a portion having a small metal flow is stretched in the rolling direction without being filled, so that the tendency of not being further filled is promoted. As a result, the thickness of the unfilled portion does not match the groove of the roll. Due to such a phenomenon, the plate thickness and the inclination angle at each thick portion in the plate width direction of the product become uneven, and a predetermined product shape cannot be obtained.
Specifically, it has been found that the ridged roll 30 having the profile shown in FIG. 4 is effective for improving the shape accuracy.
Ridge with roll 30 has a convex cross-sectional area of the protrusions _{P 31, P 32, P 33} forming the thin part _{S 31, S 32, S 33} , and the protrusions _{P 31, P 32, P 33} What is the ratio between the value obtained by integrating １ ／ of the concave cross-sectional area of each of the groove portions G _{1 to} G _{4 that} are continuously adjacent and form the thick portions S ₁₁ , S ₁₂ , S ₁₃ , and S _14? protrusions _{P 31, P 32,} to be constant even in the _{P 33} and groove shaped portions _G 1 ~G _4, protrusions _{P 31, P 32, P 33} and groove shaped portions _G 1 ~G ₄ is designed Have been. Outside the left and right thick portions S ₁₁ , S ₁₄ , cut-off portions S ₅₁ , S _{52 in} which the thin portions S ₄₁ , S ₄₂ are formed by the disposal groove protrusions P ₄₁ , P ₄₂ are provided.
[0012]
Considering the process in which the left side of the thick portion S ₁₁ is formed, the meat metal strip S which corresponds to this portion had initially, the metal flow from the left and right of the thin portion S ₃₁ and S ₄₁ is applied. Further, the thick portion _{S 12} in the center, the meat increased by the metal flow from the left and right of the thin portion _{S 31, S 32.} Therefore, as shown in FIG. 4 (b), half of the cross-sectional area of protrusions P a half of the cross-sectional area A of _41, half B, and C of the cross-sectional area of the groove portion G _1, protrusions P ₃₁ D and E, groove portion G ₂ of the half of the cross-sectional area F and G, protrusions half H and I of the cross-sectional area of the P _32, half the J and K of the cross-sectional area of the groove portion G _3, when half L and M of the cross-sectional area of the projecting portion P _33, half N and O of the cross-sectional area of the groove portion G _4, a half of the cross-sectional area of the protrusions P ₄₂ is P, the thick portion S ₁₁ cross sectional area ratio in the area ▲ 1 ▼ affecting the formation of (a + D) / (B + C), the cross-sectional area ratio in the region ▲ 2 ▼ affecting the formation of the thick portion _{S 12 (E + H) /} (F + G), sectional area ratio in the region ▲ 3 ▼ affecting the formation of the thick portion _{S 13 (I + L) /} (J + K), the cross-sectional area ratio in the area ▲ 4 ▼ affecting the formation of the thick portion _{S 14} (M + P) / (N + O) Are set to the same value.
When the flat roll 40 is opposed to the ridged roll 30 in which the ridge portion and the groove portion are designed as described above and the metal strip S is formed, the thick portion S ₃₁ , thickness of S _{32, S 33} corresponds to the height _H 1 to H ₄ to each groove portion _G 1 ~G ₄ from the peripheral surface of the flat roll 40, the same thickness. The inclination angle theta ₁ through? ₆ of the step portion corresponds to the inclination angle theta ₁ through? ₆ side _{F 31, F 32, F 33} of the protrusions _{P 31, P 32, P 33} . As a result, a modified cross-section strip having a cross-sectional shape with high dimensional accuracy is manufactured.
[0013]
Figure 4 (a), the thin part S ₃₁ in the central _{portion, S 32,} shows the case of 3 Article producing modified cross-section strip with S _33, the metal strip after roll forming, each elongated member It is slit every time. However, the present invention is not limited to this method. For example, a method of simultaneously forming a plurality of strips or a method of simultaneously manufacturing a plurality of deformed cross-section strips having two thin portions as shown in FIG. Also applies. In this case, the provided omitter S ₅₃ between the modified cross-strip material as a product, to form a thin portion S ₄₃ for regulating the metal flow to the truncation section S _53. Correspondingly, the ridge with roll 40 to form a groove ridge portion P ₄₃ discarded in central as shown in Figure 5 (b).
As a material of the deformed cross-section strip, a single material made of Cu, Cu alloy, Al, Al alloy, steel, Fe alloy, or the like, or a composite material combining these can be used. A strip having a width equal to or greater than the width of the deformed metal strip including the cut-off portions S ₅₁ and S ₅₂ is passed between the ridged roll 30 and the flat roll 40, and is shown in FIGS. Into the irregular cross-section shown in (1). Then, the cut-off portions S ₅₁ , S ₅₂ , and S ₅₃ are cut off to obtain a product strip.
[0014]
【Example】
In this embodiment, as shown in FIG. 4 (c), the three thin portions forming protrusions _{P 31, P 32, P 33} and two discarded groove forming protrusions _{P 41, P 42} A ridged roll 30 formed on a body having a diameter of 400 mm was used. The ridges P ₃₁ , P ₃₂ , and P ₃₃ have a height of 1.75 mm, a length of the top surface in the roll axis direction of 11.5 mm, and inclination angles θ _{1 to} θ _{6 of} the slopes F ₃₁ , F ₃₂ , and F ₃₃ of 30. The trapezoidal cross section was symmetrical in degree. The length of each of the groove portions G _{1 to} G ₄ in the roll axis direction was set to 13.88 mm. The ridges P ₄₁ , P ₄₂ for forming the discard grooves had a top surface length of 6 mm in the roll axis direction. At this time, the sectional area ratio (A + D) / (B + C) of the area (1), the sectional area ratio (E + H) / (F + G) of the area (2), and the sectional area ratio (I + L) / (J + K) of the area (3) , And the area ratio (M + P) / (N + O) of the area (4) has the same value of 0.83.
For comparison, at the position where the cross-sectional area ratios (A + D) / (B + C) and (M + P) / (N + O) of the areas (1) and (4) are 0.65, the length of the top surface in the roll axis direction is 6 mm. Rolls (Comparative Example 1) on which the ridges P ₄₁ and P ₄₂ for forming the discarded grooves are formed, and the cross-sectional area ratios (A + D) / (B + C) and (M + P) / of the areas (1) and (4) A roll with ridges (Comparative Example 2) in which ridges P ₄₁ and P ₄₂ for forming disposal grooves having a top surface with a roll axial length of 6 mm at a position where (N + O) is 1.2 was used. .
[0015]
Each ridged roll was opposed to a flat roll, and a normal steel strip having a thickness of 2.3 mm and a width of 110 mm was passed through as a strip to be rolled to produce a strip having a modified cross section.
FIG. 6 shows the results of measuring the shape of each part of the obtained irregularly shaped cross-section strip.
As shown in FIG. 6 (a), the deformed cross-section strip manufactured by using the ridged roll according to the present invention corresponds to the inclination angles of the step slopes F ₃₁ , F ₃₂ and F ₃₃ . The inclination angle was also a substantially constant value of 35 degrees.
On the other hand, in Comparative Example 1 in which the ridges P ₄₁ and P ₄₂ for the discarding groove were moved toward the center of the roll, the inclination angle of the central step portion was large, and was larger than the angles θ ₃ and θ _{4 of the} inclined surface F _32. It has grown. On the other hand, in Comparative Example 2 in which the ridges P ₄₁ , P ₄₂ for the discard groove are extended from the center of the roll to both sides, the inclination angles of the step portions on both sides are large, and the angles θ _{1 of} the inclined surfaces F ₃₁ , F ₃₃ are large. It becomes larger than θ _6. From this, it can be seen that when the ridges P ₄₁ and P ₄₂ for the discard groove are not at the proper positions, the influence of the metal flow flowing in the left-right direction greatly appears.
[0016]
Forming the ridges P ₄₁ , P ₄₂ for disposal grooves at appropriate positions is effective in making the thick portions S ₃₁ , S ₃₂ , S ₃₃ uniform in thickness as shown in FIG. It is valid.
That is, when the ridged roll according to the present invention is used, each of the thick portions S ₃₁ , S ₃₂ , and S ₃₃ is formed from the flat roll 40 to the groove portions G _{1 to} G ₄ of the ridged roll 30. It had a substantially equal 2.5mm in height _H 1 to H _4. The thicknesses t ₁ and t ₂ outside the cut-off thin portions S ₄₁ and S ₄₂ were reduced to 2.4 mm due to the influence of the metal flow to the side. However, since the truncated portions S ₅₁ and S ₅₂ are removed to obtain a strip with a modified cross section, the lack of the thicknesses t ₁ and t ₂ does not affect the product quality at all.
On the other hand, in Comparative Example 1 in which the ridges P ₄₁ and P ₄₂ for the discarding groove were moved toward the center of the roll, the influence of the metal flow flowing outward in the sheet width direction was not completely removed, and both sides were not removed. Insufficient meat occurred in the thick portions S ₁₁ and S ₁₄ . On the other hand, in Comparative Example 2, in which the ridges P ₄₁ , P ₄₂ for the discard groove were expanded from the center of the roll to both sides, the lack of thickness occurred in the thick portions S ₁₂ , S ₁₃ at the center. The lack of the thickness causes a large amount of metal flow from the thin portions S ₃₁ and S ₃₃ toward the thick portions S ₁₁ and S _14, and the thin portions S ₃₁ and S _{33 correspond} to the thick portions S ₁₂ and S _13. It is probable that the metal flow toward the site decreased.
[0017]
【The invention's effect】
As described above, in the present invention, the ridged roll having the ridge for the discard groove formed at an appropriate position on both sides of the ridge for forming the thin portion is opposed to the flat roll, and the strip to be rolled is formed. By passing through, the influence of the metal flow outward in the width direction of the plate is eliminated, and the metal flow from each thin portion to the thick portion is adjusted. As a result, a sufficient amount of meat is supplied to the groove-shaped space portion of the ridged roll, the profile of the ridged roll is accurately transferred, and a modified cross-section strip having good shape accuracy is manufactured. In this method, it is not necessary to prepare various rolls for manufacturing one type of deformed cross-section strip, and a deformed cross-section strip suitable as a lead frame, a bearing retainer, or the like can be obtained with high productivity. Further, since strips having different cross-sections with different shapes are manufactured simply by replacing the rolls with the ridges, production according to various needs becomes possible.
[Brief description of the drawings]
FIG. 1 is a process for producing a modified cross-section strip according to a conventional method. FIG. 2 is a process for producing a modified cross-section strip according to another conventional method. FIG. 3 is a diagram illustrating a process for producing a modified cross-section strip using a ridged roll. FIG. 4 shows a state in which a roll with a ridge according to the present invention is opposed to a flat roll to produce a strip with an irregular cross section (a), a sectional area ratio of each part (b), and a ridge. Roll appearance (c)
FIG. 5 shows a state in which two deformed cross-section strips each having two thin portions are simultaneously formed (a) and the appearance of a roll with a ridge used (b).
FIG. 6 is a graph comparing the inclination angle (a) of a stepped portion and the thickness (b) of a thick portion of a strip with a modified cross section manufactured in an example of the present invention with a comparative example.
S: metallic strip S ₁₁ to S _14: Product thick portion S ₃₁ to S _33: thin portion _{S 41,} S _42: truncated thin-walled section _{S 51,} S _52: omitter _{t 1,} t _2: the truncated portion thickness 30: present invention in accordance with protrusions with the roll P ₃₁ to P _33: ridge P _{41, P 42:} for discarding grooved ridges G ₁ ~G _4: groove portion F ₃₁ ~F _33, F ₄₁ , F ₄₂ : slope of stepped portion θ _{1 to} θ ₆ : slope angle of slope H _{1 to} H ₄ : height from flat roll to groove-shaped portion (≒ plate thickness of product thick portion)
40: Flat roll

Claims (2)

When manufacturing a strip with irregular cross-section by roll forming with a ridged roll and a flat roll with a plurality of ridges formed through a plurality of grooves in the roll axis direction, a groove that forms a thick part of the product A ridge portion for a discard groove is formed on the outer side in the roll axis direction of the portion, and the cross-sectional area of the groove portion forming the thick portion of the product , including the ridge portion for the discard groove, is formed on both sides of the groove portion. Use a roll with ridges provided with grooves and ridges so that the ratio of the cross-sectional area of each ridge to the integrated value of 1/2 of each product is constant at the thick part of each product. Wherein a metal strip at least equal to the distance between the ridges for the abandonment groove is passed between the roll with ridges and the flat roll. A roll formed opposite to the flat roll to form a deformed cross-section strip having a plurality of thick portions, and a ridge portion for disposal grooves is formed outside the groove portion forming the product thick portion in the roll axis direction. And the integrated value of 1/2 of the cross-sectional area of the groove forming the thick part of the product , including the ridge for the discarded groove, and the cross-sectional area of each of the ridges on both sides of the groove. A roll with protrusions provided with a plurality of protrusions via a plurality of grooves along the roll axis direction so that the ratio of the thickness to the thickness of each product is constant.

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