JP2009148805A - Dieless working method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dieless working method by which a workpiece can be deformed into a cross section of similar figure to the cross sectional shape before working even the workpiece is whatever shape. <P>SOLUTION: This invention is applied to a dieless working method by which the heated part of the workpiece is deformed by imparting tensile force or compressive force in the longitudinal direction by a moving means while heating a long size workpiece W from the outer periphery by a heating means. In this method, when heating the workpiece W, heat input quantity to the outer peripheral surface of the workpiece by the heating means is changed depending a position in the peripheral direction corresponding to the cross-sectional shape of the workpiece W. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dieless machining method and a related technique for deforming a long workpiece in a cross-sectional direction.

  Conventionally, as a technique for reducing the diameter of a long workpiece such as an extruded material without using a die, for example, a dieless processing method shown in Patent Document 1 below is well known.

In this dieless processing method, the heated portion of the workpiece is reduced in diameter by being pulled in the axial direction while uniformly heating the workpiece made of the extruded material from the entire circumferential direction at a predetermined position.
JP-A-48-81761 (Claims and Drawings)

  However, in the conventional dieless processing method shown in Patent Document 1, when trying to process a workpiece having an irregular cross-sectional shape such as a non-circular cross-section, the cross-sectional shape before the processing is accurate to a similar cross-section. There was a problem that it was difficult to deform.

  The present invention has been made in view of the above-described problems, and can perform dieless machining that can accurately deform a cross-sectional shape before processing into a similar cross-section regardless of the cross-sectional shape before processing. The object is to provide a method and related techniques.

  In order to achieve the above object, the present invention has the following structure.

  Here, in the present invention, the term “long work” refers to an “axial center with respect to at least one dimension (cross-sectional dimension) of the longitudinal direction (height direction) and lateral direction (width direction) of the work section. In the present invention, “a workpiece whose axial length is at least three times the cross-sectional dimension” is referred to as a “long workpiece”. It can be used suitably.

[1] A dieless machining method in which a heating part of a workpiece is deformed by applying a tensile force or a compressive force in a length direction while heating a long workpiece from the outer periphery by a heating means,
A dieless machining method characterized in that, when a workpiece is heated, the amount of heat input to the workpiece outer peripheral surface by the heating means is changed according to the position in the circumferential direction according to the cross-sectional shape of the workpiece.

  [2] The dieless machining method according to item 1, wherein the workpiece has a different heat capacity depending on the position in the circumferential direction, and the amount of heat input by the heating means is changed according to the heat capacity.

  [3] The workpiece has peripheral walls having different thicknesses depending on positions in the circumferential direction, and the thicker portion of the peripheral walls increases the amount of heat input by the heating means than the thin portion. Or the dieless processing method of 2.

  [4] The work has a peripheral wall having a polygonal cross section in which a large number of flat wall portions are connected in the circumferential direction. Among the wall portions, a wall portion having a large cross-sectional area is compared with a wall portion having a small cross-sectional area. The dieless processing method according to any one of the preceding items 1 to 3, wherein an amount of heat input by the heating means is increased.

  [5] The dieless processing method according to any one of the preceding items 1 to 4, wherein a temperature difference between the maximum temperature and the minimum temperature is set to 50 ° C. or less in the material temperature in a cross-sectional state in the heating portion of the workpiece.

  [6] The dieless machining method according to any one of items 1 to 5, wherein the temperature in the heating part of the workpiece is set to 450 ° C. or higher.

  [7] The work has a peripheral wall having a polygonal cross section in which a large number of flat wall portions are connected in the circumferential direction, and a corner between adjacent wall portions is inserted by a heating means as compared with other portions. The dieless processing method according to any one of items 1 to 6, wherein the amount of heat is reduced.

  [8] The dieless processing method according to any one of items 1 to 7, wherein the heating part of the workpiece is raised to a solid solution temperature.

  [9] The dieless processing method according to any one of items 1 to 8, wherein a workpiece made of aluminum or an alloy thereof is used.

  [10] The dieless machining method according to any one of items 1 to 9, wherein a workpiece having an irregular cross section is used.

[11] A dieless machining apparatus configured to deform a heating part of a work by applying a tensile force or a compressive force in a length direction while heating a long work by a heating means from the outer periphery,
The dieless processing apparatus, wherein the heating means is configured to be able to change the amount of heat input to the outer peripheral surface of the workpiece depending on the position in the circumferential direction of the workpiece.

  [12] The dieless machining apparatus according to the above item 11, wherein the heating means includes a plurality of heaters arranged in the circumferential direction on the outer periphery of the workpiece.

  [13] The dieless processing apparatus according to item 12, wherein the output heat amount of each heater is individually adjustable.

  [14] The dieless processing apparatus according to item 12 or 13, wherein the heater is configured to be movable in a contact / separation direction with respect to the workpiece.

[15] A work heating method for a dieless machining apparatus in which a heating part of a work is deformed by applying a tensile force or a compressive force in a length direction while heating a long work by a heating means from the outer periphery. There,
A work heating method for a dieless machining apparatus, wherein a heat input amount to a work outer peripheral surface by a heating means is changed according to a position in a circumferential direction according to a cross-sectional shape of the work.

[16] A workpiece heating apparatus for a dieless processing apparatus that deforms a heating section of a workpiece by applying a tensile force or a compressive force in a length direction while heating a long workpiece from the outer periphery,
A work heating device for a dieless machining apparatus, wherein the amount of heat input to the work outer peripheral surface can be changed depending on a position in a circumferential direction of the work.

  According to the dieless machining method of the invention [1], any cross-sectional workpiece can be heated to a substantially uniform temperature over the entire circumference of the heating unit. It can be accurately deformed into a similar cross section.

  According to the dieless machining method of the invention [2] to [7], the workpiece can be deformed with higher accuracy.

  According to the dieless processing method of the invention [8], a quenching effect can be obtained and the quality of the dieless processed product can be improved.

  According to the dieless processing method of the invention [9], a high-quality aluminum dieless processed product can be obtained.

  According to the dieless processing method of the invention [10], a high-quality dieless processed product can be obtained with an irregular cross section.

  According to the dieless processing apparatus of the invention [11], any cross-sectional workpiece can be heated to a substantially uniform temperature over the entire circumference of the heating unit. It can be accurately deformed into a similar cross section.

  According to the dieless processing apparatus of the invention [12] to [14], the workpiece can be deformed with higher accuracy.

  According to the invention [15], similarly to the above, it is possible to provide a work heating method for a dieless machining apparatus that exhibits the same effect.

  According to the invention [16], similarly to the above, it is possible to provide a workpiece heating device for a dieless processing device that exhibits the same effect.

<First Embodiment>
FIG. 1 is a side sectional view schematically showing a dieless machining apparatus according to a first embodiment of the present invention, and FIG. 2 is a front sectional view schematically showing a workpiece heating unit of the dieless machining apparatus. As shown in both figures, this dieless machining apparatus conveys a long workpiece (W) along the conveyance path (P) to the downstream side (conveyance direction X) along the length direction (axial direction). The workpiece (W) having a modified cross section is subjected to diameter reduction processing as will be described later.

  This dieless processing apparatus includes a feeding device (1), a heating device (3), a cooling device (4), and a tensioning device (2) in order from the upstream side of the transport path (P). Further, a region from the heating device (3) to the cooling device (4) on the transport path (P) is configured as a deformation processing region (R), and the workpiece (W) is deformed in the deformation processing region (R). The

  The feeding device (1) includes a chuck (11) capable of gripping the upstream end (base end) of the workpiece (W), and a chuck drive for moving the chuck (11) along the transport direction (X). Means (not shown). Then, in a state where the base end of the workpiece (W) is held (held) by the chuck (11), the chuck (11) is moved in the transport direction (X) by the chuck driving means, whereby the base of the workpiece (W) is obtained. The end portion is pushed and conveyed downstream along the conveyance path (P).

  The tension device (2) includes a chuck (21) capable of gripping the downstream end (tip) of the work (W), and chuck driving means (moving the chuck (21) along the transport direction (X)). (Not shown). Then, with the chuck (21) gripping (holding) the base end portion of the workpiece (W), the chuck (21) is moved in the transport direction (X) by the chuck driving means, thereby leading the tip of the workpiece (W). The part is drawn and transported downstream along the transport path (P). In the present embodiment, the tension device (2) constitutes means for applying a tensile force or a compressive force to the workpiece (W).

  In this embodiment, as will be described later, the tension speed (V2) of the workpiece (W) by the tension device (2) is set faster than the pushing speed (V1) of the workpiece (W) by the feeding device (1). Thus, a tensile force along the length direction is applied to the workpiece (W), and a predetermined portion (heating portion) of the workpiece (W) is reduced in diameter and thinly deformed by the tensile force.

  In the present embodiment, the moving speed (V1) (V2) of the work (W) by the feeding device (1) and the tensioning device (2) is configured to be freely adjustable. For example, the feeding device ( By setting the pulling speed (V2) of the work (W) by the pulling device (2) to be slower than the pushing speed (V1) of the work (W) by 1), the work (W) was along the length direction. It is also possible to apply a compressive force and cause the predetermined portion (heated portion) of the workpiece (W) to be expanded in diameter and increased by the compressive force.

  One heating device (3) arranged corresponding to the upstream end of the deformation processing area (R) is arranged on each of the four sides of the upper, lower, left, and right (upper and lower sides) around the conveyance path (P). The four heaters (31) to (34) are provided, and the work (W) can be individually heated from the outer periphery by the heaters (31) to (34).

  As each heater (31)-(34), a flame type heating means for heating using a flame, an electromagnetic induction type heating means for heating using electromagnetic induction, a plasma type heating means for heating using plasma A laser heating means for heating using a laser can be suitably used.

  Furthermore, each heater (31)-(34) is comprised so that the heat input amount (input heat amount) to the outer peripheral surface of a workpiece | work (W) can be adjusted. For example, as each of the heaters (31) to (34), one that can change the amount of output heat is adopted, and the amount of heat input can be adjusted by changing the amount of output heat. That is, in the present embodiment, by adjusting the output heat amount of each of the heaters (31) to (34), different amounts of heat can be given to the respective surfaces on the four side surfaces around the workpiece (W). It is configured.

  In the present invention, the heat input is the amount of heat (calories) given to the outer peripheral surface of the work (W) per unit time.

  Moreover, in this embodiment, the heating apparatus (3) comprises the heating means and the workpiece | work heating apparatus.

  The cooling device (4) is configured to rapidly cool the work (W) locally in the axial direction and in the entire area in the circumferential direction.

  As the cooling device (4), a water-cooled cooling device that blows a coolant such as cooling oil on the workpiece (W), an air-cooled cooling device that blows cooling air, or the like can be suitably used.

  Moreover, in the dieless processing apparatus of the present embodiment, a control device (not shown) constituted by a personal computer or the like is provided, and by this control device, a feeding device (1), a tension device (2), a heating device. The operations described below are automatically performed by controlling the driving of each drive unit such as (3) and the cooling device (4).

  In addition, the workpiece | work (W) processed with the dieless processing apparatus of this embodiment is comprised by metals, such as aluminum (including the alloy), for example, and is comprised by the extrusion material obtained by extrusion molding, for example. Yes. Furthermore, the workpiece (W) has a shape of an irregular cross section such as a non-circular cross section, and in this embodiment, as shown in FIG. 1, the thickness of one side wall (W2) is thick and the other wall portion, A workpiece (W) having a rectangular cross-sectional shape in which the upper and lower walls (W1) (W3) and the other side wall (W4) are formed thin is processed.

  Furthermore, the processed product manufactured by the dieless processing apparatus of this embodiment is used as a member for transportation equipment such as an automobile, a member for construction, or the like.

  In order to machine the workpiece (W) in the present embodiment, first, the workpiece (W) is set in a dieless machining apparatus. That is, both ends of the workpiece (W) are held by the chucks (11) and (21) of the feeding device (1) and the tension device (2), and the workpiece (W) is arranged along the transport path (P).

  In this state, when the operation of the dieless processing apparatus is started, the workpiece (W) is pushed in the conveyance direction (X) by the feeding device (1), while the tip side of the workpiece (W) is conveyed by the tension device (2). By being pulled in the direction (X), the work (W) is transported along the transport path (P). At the time of this conveyance, the tensile speed of the tension device (V2) is set faster than the pushing speed (V1) of the feeding device (1), and the tensile force acts on the workpiece (W).

  In this way, the workpiece (3) is heated from the entire circumference by the heating device (3) at the upstream end of the deformation processing zone (R) while the workpiece (W) is being conveyed.

  At the time of this heating, in this embodiment, the amount of heat input to the work (W) by the heating device (3) is appropriately adjusted according to the position in the circumferential direction. That is, as described above, since the workpiece (W) is formed such that the thickness of the one side wall (W2) is thick and the thickness of the other wall portions (W1) (W3) (W4) is thin, W2) has a larger heat capacity than the other wall portions (W1), (W3), and (W4). In the present embodiment, the heat input amount by the heating device (3) is set to be large for the portion where the heat capacity of the workpiece (W) is large, and the heat input amount by the heating device (3) is set for the portion where the heat capacity is small. Set the amount of heat small. For example, in the heating device (3), the heater (32) corresponding to one side wall (W2) of the work (W) sets the output heat amount to be large and the other wall portions (W1) (W3) (W4). The heaters (31), (33), and (34) corresponding to (1) set the output heat amount to be small. As described above, the amount of heat input is appropriately adjusted according to the heat capacity in the circumferential direction of the workpiece (W). Therefore, the workpiece (W) has a substantially uniform temperature in the entire area of the heating part in the sectional state regardless of the sectional shape. It is heated to become.

  In this state, the heated portion is easily deformed, and in this state, the heated portion of the workpiece (W) is stretched in the deformation processing region (R) by the tensile force acting on the workpiece (W), and the reduced diameter and Thinly deformed. At the time of this deformation, since the whole area of the material of the heating part is heated to a substantially uniform temperature, the workpiece (W) is uniformly deformed in a well-balanced manner throughout the entire area of the material, so that the workpiece has an accurate similar shape to the sectional shape before processing. Deformed with high accuracy.

  On the other hand, when the workpiece (W) passes through the position of the cooling device (4) after being deformed in the deformation processing region (R), the passing portion is cooled by the cooling device (4) and consolidated (freeze). As a result, the deformation resistance is high and the deformation is difficult (stabilized state).

  In this way, the workpiece (W) is continuously fed into the deformation processing region (R) and sequentially deformed, and the intermediate required region in the workpiece (W) is continuously reduced in diameter and thinly deformed.

  In the present embodiment, when the workpiece (W) is heated by the heating device (3), the workpiece (W) is heated to the solid solution temperature, rapidly cooled by the cooling device (4), and frozen (consolidated). In this case, a stable quenching effect can be surely obtained, and a high-quality dieless processed product can be obtained with excellent hardness.

  As described above, according to the dieless processing apparatus of the present embodiment, the heating devices (3) are arranged along the circumferential direction, and the plurality of heaters (31) to (34) that can individually change the output heat amount. The amount of heat input is appropriately changed for each position in the circumferential direction according to the cross-sectional shape of the workpiece (W). That is, of the peripheral wall portion of the workpiece (W), one wall (W2) having a large wall thickness and a large heat capacity is heated to increase the amount of heat input, and the other wall having a small wall thickness and a small heat capacity is heated. The parts (W1), (W3), and (W4) are heated so that the amount of heat input is reduced. Therefore, even if the workpiece (W) has an irregular cross section, the entire area of the material of the heating section is almost uniform in the cross-sectional state. The workpiece (W) is uniformly reduced in diameter and thinly in a well-balanced manner around the entire circumference due to the tensile force acting on the workpiece (W), and is processed into an accurate similar shape to the cross-sectional shape before processing. can do.

  In addition, since the amount of heat input is appropriately adjusted according to the heat capacity in the circumferential direction of the workpiece (W), the entire material of the workpiece heating part can be efficiently heated, and the temperature can be shortened to a high temperature suitable for deformation processing. It can be heated in time, and the production efficiency can be improved while eliminating the uneven temperature distribution.

  Here, as described in detail later in this embodiment, when heating the workpiece (W), the temperature difference between the highest temperature and the lowest temperature is more preferably 50 ° C. or less in the material temperature of the heating portion in the cross-sectional state. Is preferably set to 30 ° C. or lower. That is, when this temperature difference is adjusted within a specific range, the workpiece (W) is deformed evenly in a well-balanced manner in the entire circumferential direction by the tensile force acting on the workpiece (W), and the cross-sectional shape before processing is accurate. It is possible to form a similar shape. In other words, if the temperature difference is too large, that is, if there is variation in the temperature distribution of the heating part, the amount of deformation of the workpiece (W) varies due to the tensile force acting on the workpiece (W), and the machining accuracy is reduced. It may be difficult to form an accurate similar shape with respect to the cross-sectional shape before processing.

  Furthermore, in this embodiment, when heating a workpiece | work (W), it is good to set the heating temperature to 450 degreeC or more, More preferably, it is 480 degreeC or more. In other words, when the heating temperature is adjusted beyond a specific level, the deformation force (tensile force) required for deformation of the workpiece (W) is reduced, and the workpiece (W) can be deformed smoothly and efficiently. . In other words, if the heating temperature is too low, the deformation force required for deformation of the workpiece (W) increases, and it may be difficult to deform the workpiece (W).

  In the present invention, the amount of heat input for each position in the circumferential direction varies depending on the type of workpiece. Therefore, before actually performing dieless machining, a simulation by a finite element method (FEM) or the like is performed in advance as described later. It is preferable to obtain a heating condition (heat input amount) at each portion in the circumferential direction so that the workpiece to be machined can be heated most efficiently, and to perform actual dieless machining according to the heating condition.

  By the way, in the present embodiment, the amount of heat input is adjusted according to the heat capacity of the peripheral wall in the workpiece (W), but since the heat capacity is proportional to the cross-sectional area, according to the cross-sectional area of the peripheral wall, The amount of heat input can be adjusted. For example, as shown in FIG. 3, the width (height) of each wall (W1) to (W4) of the workpiece (W) is “H1”, “H2”, “H3”, “H4”, and each thickness is “T1”. When “T2”, “T3”, and “T4” are set, the heat input amount is maximized for the largest wall portion among “H1 × T1”, “H2 × T2”, “H3 × T3”, and “H4 × T4”. For the smallest wall, the heat input is minimized. For example, if “H1 × T1”> “H2 × T2”> “H3 × T3”> “H4 × T4”, the amount of heat input (Q1) to each wall (W1) to (W4) (Q4) is preferably adjusted so that “Q1”> “Q2”> “Q3”> “Q4”.

Second Embodiment
FIG. 4 is a front sectional view schematically showing a workpiece heating unit of a dieless machining apparatus according to a second embodiment of the present invention. As shown in the figure, in this dieless processing apparatus, a total of eight heaters (31) to (34) are provided with two heating devices (3) arranged on each of the four sides around the top, bottom, left and right (upper and lower sides). ).

  In the present embodiment, each of the heaters (31) to (34) is provided so as to be movable toward and away from the workpiece (W), and the heaters (31) to (34) with respect to the workpiece (W). By appropriately changing the distances (D1) to (D4), the amount of heat applied to the workpiece (W) can be adjusted.

  For example, in the state of FIG. 4A, the distances (D1) to (D4) between the heaters (31) to (34) and the work wall portions (W1) to (W4) are all set equal. If the output heat amounts of the heaters (31) to (34) are the same, uniform heat amounts are given to the four sides around the work (W), while in the state of FIG. The distance between workpieces (D2) and (D4) of the heaters (32) and (34) is adjusted to be shorter than the distance between workpieces (D1) and (D3) of the upper and lower heaters (31) and (33). Even if the output heat amounts of the chambers (31) to (34) are the same, the heat input amount to the both side walls (W2) (W4) of the work (W) becomes the heat input amount to the upper and lower walls (W1) (W3). Compared to more.

  In the second embodiment, since the other configuration is the same as that of the first embodiment, the same parts are denoted by the same or corresponding reference numerals, and the duplicate description will be omitted.

  The workpiece (W) processed in the second embodiment has a horizontally long rectangular cross-sectional shape in which both side walls (W2) (W4) are thick and the top and bottom walls (W1) (W3) are thin. is doing.

  When heating the workpiece (W), as shown in FIG. 4 (b), the heaters (32) and (34) on both sides are heated close to the workpiece (W). The upper and lower heaters (31) and (33) are heated away from the workpiece (W). As a result, the amount of heat input increases for both side walls (W2) and (W4) of the workpiece (W) having a large heat capacity, and the amount of heat input for the upper and lower walls (W1) and (W3) having a small heat capacity. Less. Accordingly, the workpiece (W) is heated so as to have a substantially uniform temperature in the entire area of the material of the heating portion in a cross-sectional state.

  Since the workpiece (W) is heated to a uniform temperature over the entire heating portion of the workpiece (W), the workpiece (W) is uniformly reduced in diameter and thinly in a well-balanced manner around the entire circumference of the heating portion by the tensile force acting on the workpiece (W). Can be deformed.

  As described above, also in the dieless machining apparatus of the second embodiment, the workpiece (W) can be machined into an accurate similar shape with respect to the cross-sectional shape before machining, as in the first embodiment. In addition, the entire circumference of the heating part of the workpiece (W) can be efficiently heated, and the production efficiency can be improved.

  In the second embodiment, by changing the distances (D1) to (D4) between the heaters (31) to (34) in the heating device (3), the circumferential direction of the workpiece (W) is changed. The amount of heat is adjusted. However, the present invention is not limited to this, and each of the heaters (31) to (34) can be used to adjust the amount of output heat in the same manner as in the first embodiment. And the change of the distance may be used in combination, and the amount of heat input in the circumferential direction with respect to the workpiece may be appropriately adjusted.

<Modification>
In the above embodiment, the case where the present invention is applied to the rectangular pipe-shaped workpiece (W) having a rectangular cross section has been described as an example. However, the present invention is not limited thereto, and in the present invention, the cross section of the workpiece (W). The shape is not particularly limited, and can be applied to a workpiece having a cross-sectional shape of a triangle or a pentagon, and is not limited to a polygonal shape, but also a workpiece such as an ellipse or an oval, or a combination of these shapes. It can be applied to a workpiece having a so-called irregular cross section. Furthermore, the present invention is not limited to pipe-shaped workpieces but can be applied to solid-structured workpieces such as rod-shaped workpieces.

  Moreover, even if the outer periphery is formed in a perfect circle as shown in FIG. 5, in the work (W) whose thickness varies depending on the position in the circumferential direction, the heat input amount of the thick portion (the portion having a large heat capacity) is increased. As described above, by applying the present invention, it can be efficiently deformed with high processing accuracy as described above.

  In the above-described embodiment, the case where four or eight heaters (31) to (34) are arranged in the heating device (3) has been described as an example, but the number of heaters is particularly limited. In short, any heating device may be adopted as long as the amount of heat input can be partially changed in the circumferential direction.

  In the above embodiment, a tensile force is applied to the workpiece (W) so that the heating portion of the workpiece (W) is reduced in diameter and thickness. However, the present invention is not limited to this, and in the present invention, the workpiece (W) is deformed. A heating force of the workpiece (W) may be deformed by increasing the diameter of the workpiece (W).

  Furthermore, you may make it perform the diameter reduction thin wall deformation | transformation by a tensile force, and the diameter expansion wall thickness deformation | transformation by a compressive force with respect to one workpiece | work (W).

  Moreover, in this invention, when arrange | positioning a some heater, you may make it arrange | position along the circular arc line in a workpiece | work outer periphery.

<Example 1>
As shown in FIG. 6, in the rectangular pipe-shaped workpiece (W) having a rectangular cross section, the upper and lower walls (W1) (W3) are thin and the both side walls (W2) (W4) are thick. W1) and one side wall (W2) are each divided into eight equal parts, and the divided parts are designated as “a1” to “a8” and “b1” to “b8”, respectively. Then, with the goal of heating the workpiece (W) to 500 ° C., the heat input for each part (a1) to (a8), (b1) to (b8) is heated for 15 seconds under the conditions shown in the table of FIG. Assuming the case, the simulation was performed by the finite element method (FEM), and the temperature distribution in the cross-sectional state of the workpiece (W) was obtained.

  Specifically, the heat input is set to “450” for the portions (a1), (a8), (b1), and (b8) on the outer peripheral surface of the workpiece (W), and the heat input is set to “750” for the portions (a2) and (a7). And the portions (a3) to (a6) are set to “650”, the portions (b2) and (b7) are set to “1000”, and the portions (b3) to (b6) Set the heat input to “1200”. Note that the amount of heat input (the amount of heat) indicates only the magnitude and has no units and is dimensionless (the same applies to the following examples, comparative examples, and reference examples).

  FIG. 7 shows the temperature distribution in the cross-sectional state of the workpiece (W) when heated under these heating conditions. As shown in the figure, although the temperature decreased from the outside to the inside of the peripheral walls (W1) to (W4), the maximum temperature was 510 ° C, the minimum temperature was 478 ° C, and the temperature difference was 32 ° C.

  Since the workpiece (W) to be inspected has a symmetrical shape, the lower wall (W3) has the same temperature distribution as the upper wall (W1), and the other side wall (W4) has the same temperature distribution as the one side wall (W2). (The same applies to the following examples, comparative examples, and reference examples).

<Comparative Example 1>
As shown in FIG. 10, in the workpiece (W) having the same shape as in the first embodiment, as shown in the heating conditions in the table of the figure, the portions (a1) to (a8) of the wall portions (W1) (W2). ) And (b1) to (b8), the temperature distribution in the cross-sectional state of the workpiece (W) was obtained in the same manner as described above except that the heat input amounts were all set equal to “750”. The result is shown in FIG.

  As shown in the figure, the temperature of both side walls (W2) (W4) is lower than that of the upper and lower walls (W1) (W3), the maximum temperature is 507 ° C., the minimum temperature is 431 ° C., and the temperature difference is 76. It was ℃.

<Evaluation 1>
As in Example 1, the thick part of the workpiece (W) increases the amount of heat input, the thin part decreases the amount of heat input, and the corners between adjacent wall parts are more likely to transmit heat. The temperature difference in the cross-sectional state can be reduced to 32 ° C. by decreasing the amount of heat input to the corner and gradually increasing the amount of heat input as the distance from the corner increases (towards the middle of the wall). In this way, when a tensile force is applied to the workpiece (W) set at a substantially uniform temperature in the entire area of the material of the heating section in the cross-sectional state, the workpiece (W) is uniformly reduced in a well-balanced manner on the entire circumference. The diameter and thin wall can be deformed and processed into an accurate similar shape to the cross-sectional shape before processing.

  On the other hand, as in Comparative Example 1, when a uniform heat input was applied to any part of the entire circumference of the workpiece (W), the temperature difference in the cross-sectional state of the workpiece (W) was 76 ° C. Become bigger. In this way, when a tensile force is applied to the workpiece (W) having a variation in the material temperature of the heating part, the amount of deformation of the workpiece (W) varies in the circumferential direction, and the machining accuracy is reduced. It is difficult to form an accurate similar shape to the cross-sectional shape before processing.

In addition, the graph showing the relationship between the temperature of a workpiece | work (W) and 0.2% yield strength is shown in FIG. As shown in the graph, when the temperature of the workpiece (W) is around 500 ° C and the temperature distribution (temperature difference) is within the range of 30 ° C, the proof stress is as low as 50 N / mm ² or less, and the difference in proof strength is high or low. Is smaller than 20 N / mm ^2, and can be deformed in a well-balanced manner in the entire cross-sectional area. Therefore, in the present invention, if the temperature distribution (temperature difference) of the cross-sectional portion in the heating part of the workpiece (W) is within 30 ° C., the workpiece (W) can be uniformly deformed in a well-balanced manner on the entire circumference. Accuracy can be improved. However, in the present invention, if the temperature distribution (temperature difference) is within 50 ° C., the yield strength is relatively low, and the difference in yield strength can be made relatively small. If the distribution (temperature difference) is within 50 ° C., the processing accuracy can be sufficiently improved.

  Further, as is apparent from the graph, when the heating temperature of the workpiece (W) is 450 ° C. or higher, preferably 480 ° C. or higher, the proof stress becomes small, so the workpiece (W) can be efficiently and smoothly made with a small tensile force. Can be deformed.

<Reference Example 1>
As shown in FIG. 14, in the workpiece (W) having the same shape as described above, all the heat input amounts to the portions (a1) to (a8) and (b1) to (b8) of the wall portions (W1) and (W2) are all obtained. The temperature distribution in the cross-sectional state of the workpiece (W) was determined in the same manner as described above. In Reference Example 1, the heating time was set to 120 seconds. The result is shown in FIG.

  As shown in the figure, by setting the heating time as long as 120 seconds, the maximum temperature is 503 ° C., the minimum temperature is 492 ° C., and the temperature difference is 11 ° C. Although it is very small and can be adjusted to a substantially uniform temperature distribution over the entire material of the heating part, under these heating conditions, the heating time is very long and the productivity is significantly reduced. It seems difficult to adopt.

<Example 2>
As shown in FIG. 8, in the case of a square pipe-shaped workpiece (W) having a square cross section with the same thickness of the surrounding four side walls (W1) to (W4), heating is performed for 15 seconds under the heating conditions shown in the table of FIG. Assuming that the simulation was performed in the same manner as described above, the temperature distribution in the cross-sectional state of the workpiece (W) was obtained. The result is shown in FIG.

  As shown in the figure, it was possible to adjust the temperature distribution to be almost uniform over the entire area of the material of the heating section only by a slight temperature drop from the outside to the inside of the peripheral walls (W1) and (W2). Specifically, the maximum temperature was 505 ° C., the minimum temperature was 495 ° C., and the temperature difference was 10 ° C.

<Comparative example 2>
As shown in FIG. 12, in the workpiece (W) having the same shape as in the second embodiment, as shown in the heating conditions of the drawing, the portions (a1) to (a8) of the wall portions (W1) (W2), The temperature distribution in the cross-sectional state of the workpiece (W) was obtained in the same manner as in Example 2 except that the heat input amounts for (b1) to (b8) were all set to be the same. The result is shown in FIG.

  As shown in the figure, in the comparative example 2, the temperature is greatly decreased from the outside to the inside of the peripheral walls (W1) and (W2), compared to the above example 2, and the temperature distribution varies. It was. Specifically, the beloved temperature was 507 ° C., the minimum temperature was 477 ° C., and the temperature difference was 30 ° C.

<Evaluation 2>
As is clear from Example 2 and Comparative Example 2, in the square pipe-shaped workpiece (W) having the same peripheral wall thickness over the entire circumference, the amount of heat input is set to be small at corners that are susceptible to heat. Thus, the temperature distribution can be adjusted to a substantially uniform temperature throughout the entire material. Therefore, even when the thickness is the same, an excellent effect can be obtained by applying the present invention to a workpiece having a polygonal cross section.

<Reference Example 2>
As shown in FIG. 16, in the workpiece (W) having the same shape as in the second embodiment, as shown in the heating conditions in the figure, the portions (a1) to (a8) of the wall portions (W1) (W2), All the heat inputs with respect to (b1) to (b8) were set to be the same, and the temperature distribution in the cross-sectional state of the workpiece (W) was obtained in the same manner as described above. In Reference Example 2, the heating time was set to 120 seconds. The result is shown in FIG.

  As shown in the figure, by setting the heating time as long as 120 seconds, the maximum temperature is 506 ° C., the minimum temperature is 502 ° C., and the temperature difference is 4 ° C. in the cross-sectional state of the workpiece (W). Although it is very small and can be adjusted to a substantially uniform temperature distribution in the entire circumferential direction, it is difficult to actually adopt it because the heating time is very long and the productivity is significantly reduced. I think that the.

  The dieless processing method for an extruded material according to the present invention can be applied to a processing technique for deforming a long workpiece in a cross-sectional direction.

1 is a side cross-sectional view schematically showing a dieless machining apparatus according to a first embodiment of the present invention. It is front sectional drawing which shows schematically the heating part in the dieless processing apparatus of 1st Embodiment. It is front sectional drawing of the workpiece | work for demonstrating the setting method of the heat gain in this invention. It is front sectional drawing which shows a heating part roughly in the dieless processing apparatus which is 2nd Embodiment of this invention, Comprising: The same figure (a) is front sectional drawing of the state which made the distance with respect to a workpiece | work of each heater equal, The figure (B) is front sectional drawing of the state which changed the distance with respect to a workpiece | work of each heater. It is sectional drawing which shows the modification of the workpiece | work applicable to the dieless processing apparatus of this invention. It is a figure for demonstrating the temperature conditions of the heat gain of Example 1. FIG. It is sectional drawing which shows the temperature distribution state of the workpiece | work by Example 1. FIG. It is a figure for demonstrating the temperature conditions of the heat gain of Example 2. FIG. It is sectional drawing which shows the temperature distribution state of the workpiece | work by Example 2. FIG. It is a figure for demonstrating the temperature conditions of the heat gain of the comparative example 1. FIG. It is sectional drawing which shows the temperature distribution state of the workpiece | work by the comparative example 1. It is a figure for demonstrating the temperature conditions of the heat gain of the comparative example 2. FIG. It is sectional drawing which shows the temperature distribution state of the workpiece | work by the comparative example 2. 5 is a diagram for explaining a temperature condition of a heat input amount in Reference Example 1. FIG. 7 is a cross-sectional view showing a temperature distribution state of a workpiece according to Reference Example 1. FIG. 6 is a diagram for explaining a temperature condition of a heat input amount in Reference Example 2. FIG. 10 is a cross-sectional view showing a temperature distribution state of a workpiece according to Reference Example 2. FIG. It is a graph which shows the relationship between the material temperature of a workpiece | work, and 0.2% yield strength.

Explanation of symbols

2 ... Tensioning device (moving means)
3. Heating device (heating means, workpiece heating device)
31-34 ... heaters Q1-Q4 ... heat input T1-T4 ... wall thickness W ... work W1-W4 ... peripheral wall

Claims (16)

A dieless machining method in which a heating part of a workpiece is deformed by applying a tensile force or a compressive force in a length direction while heating a long workpiece by a heating means from the outer periphery,
A dieless machining method, wherein, when a workpiece is heated, the amount of heat input to the outer circumferential surface of the workpiece by the heating means is changed according to the position in the circumferential direction according to the cross-sectional shape of the workpiece.   The dieless machining method according to claim 1, wherein the workpiece has a different heat capacity depending on a position in the circumferential direction, and the amount of heat input by the heating means is changed according to the heat capacity.   The workpiece has peripheral walls having different thicknesses depending on positions in the circumferential direction, and a thicker portion of the peripheral walls has a larger amount of heat input by the heating means than a thin portion. The dieless processing method described in 1.   The workpiece has a peripheral wall with a polygonal cross section in which a large number of flat wall parts are connected in the circumferential direction, and the wall part with a large cross-sectional area among each wall part is heated compared to a wall part with a small cross-sectional area. The dieless processing method according to any one of claims 1 to 3, wherein an amount of heat input by the means is increased.   The dieless processing method according to any one of claims 1 to 4, wherein a temperature difference between a maximum temperature and a minimum temperature is set to 50 ° C or less in a material temperature in a cross-sectional state in a heating portion of the workpiece.   The dieless processing method according to any one of claims 1 to 5, wherein the temperature in the heating part of the workpiece is set to 450 ° C or higher.   The work has a peripheral wall having a polygonal cross section in which a large number of flat wall parts are connected in the circumferential direction, and the amount of heat input by the heating means is less at the corners between adjacent wall parts than at other parts. The dieless processing method according to any one of claims 1 to 6, wherein the dieless processing method is performed.   The dieless machining method according to any one of claims 1 to 7, wherein the heating part of the workpiece is raised to a solid solution temperature.   The dieless processing method according to claim 1, wherein the workpiece is made of aluminum or an alloy thereof.   The dieless processing method according to any one of claims 1 to 9, wherein a workpiece having an irregular cross section is used. A dieless machining apparatus that deforms a heating part of a workpiece by applying a tensile force or a compressive force in the length direction while heating a long workpiece by a heating means from the outer periphery,
The dieless processing apparatus, wherein the heating means is configured to be able to change the amount of heat input to the outer peripheral surface of the workpiece depending on the position in the circumferential direction of the workpiece.   The dieless processing apparatus according to claim 11, wherein the heating unit includes a plurality of heaters arranged in a circumferential direction on the outer periphery of the workpiece.   The dieless processing apparatus according to claim 12, wherein the output calorie of each heater is configured to be individually adjustable.   The dieless processing apparatus according to claim 12 or 13, wherein the heater is configured to be movable in a contact / separation direction with respect to the workpiece. It is a work heating method of a dieless processing apparatus in which a heating part of a work is deformed by applying a tensile force or a compressive force in the length direction while heating a long work by a heating means from the outer periphery,
A work heating method for a dieless machining apparatus, wherein a heat input amount to a work outer peripheral surface by a heating means is changed according to a position in a circumferential direction according to a cross-sectional shape of the work. While heating a long workpiece from the outer periphery, by applying a tensile force or a compressive force in the length direction, a workpiece heating device of a dieless processing device that deforms the heating portion of the workpiece,
A work heating device for a dieless machining apparatus, wherein the amount of heat input to the work outer peripheral surface can be changed depending on a position in a circumferential direction of the work.