JP4470907B2 - Shearing method - Google Patents

Description

  The present invention relates to a shearing method for forming a shearing molded product by extruding a molding material while shearing and deforming the molding material.

  Conventionally, an extrusion process has been performed in which a bent material passage is provided in a mold, a metal material is supplied to the material passage, and pressure is applied from the material supply port side to move the metal material to the material extrusion port. (For example, refer to Patent Document 1). According to this, when the metal material passes through the bent portion of the material passage in a pressurized state, shearing is applied, and the shearing deformation is caused by the shearing, thereby improving the properties relating to the density of the metal material.

  In the mold used in such an extrusion process, the cross-sectional shape of the material passage is formed in a circle or a square, and the material passage is sandwiched between the material supply passage on the material supply port side, It is composed of a material extrusion passage on the material extrusion port side. Then, after the metal material is filled into the material supply passage, the metal material is pressurized by a pressure member such as a plunger, passes through the material extrusion passage, and exits from the material extrusion port.

In this case, the distal end portion of the extruded shear imparting molded body is a portion located at the bent portion when the metal material is filled in the material supply passage. Therefore, since the pressure does not pass through the bent portion, no shearing is applied. In addition, the rear end portion of the shear imparting molded body is not subjected to shearing at the portion located at the bent portion at the end of the extrusion process. For this reason, the part except the front-end | tip part and rear-end part of a shear provision molded object is used as a product.
JP 2001-316789 A

  However, in the shear-imparting molded body molded by the above-described conventional method, there are many portions where the front end portion and the rear end portion are removed, so that the yield of the shear-imparting molded body is deteriorated. Further, when the metal material passes through the bent portion, a difference occurs in the shear applied between the metal material that passes through the inner corner side portion of the bent portion and the metal material that passes through the outer corner side portion of the bent portion. There is also a problem that it is difficult to form a shear-imparted molded article in a simple state.

Summary of the Invention

  The present invention has been made in order to address the above-described problems. The purpose of the present invention is to provide a shear-applying molded body having a good yield and a substantially uniform overall shape using a molding material. It is to provide a grant method.

In order to achieve the above-described object, the structural feature of the shearing application method according to the present invention is that the BiTe is in the form of a foil piece from the material supply port side to the material extrusion port side of the material passage having a bent corner. A shear application method for forming a shear application molded body by pressurizing and moving a system thermoelectric element material, wherein the BiTe thermoelectric element material is formed on both the material supply port side and the material extrusion port side of the material passage. A BiTe-based thermoelectric device is connected from the material supply port of the material passage to the shearing device in which the length of the direction along the ridgeline of the corner is longer than the length of the direction perpendicular to the ridgeline. The material supply step of supplying the element material in a stacked manner, and the BiTe thermoelectric element material supplied to the material passage are pressurized and moved from the material supply port side, and back pressure is applied to the BiTe thermoelectric element. E Bei the shear applying step of shear deformation when a child material passes a corner, the application of back pressure in the shear applying step, moveable material extrusion port side portion than the corner portions of the material path back pressure The back pressure punch is provided with a stopper for preventing the back pressure punch from entering the corner portion of the material passage .

  In the shearing application method of the present invention configured as described above, the cross section of the material passage is formed into a rectangular shape in which the length in the direction along the ridgeline of the corner is longer than the length in the direction perpendicular to the ridgeline, and the formed shear The imparted molded body is a plate-shaped body having a rectangular cross-sectional shape. For this reason, compared with the case where the passage section is formed in a circle or a square, the portion to be removed from the front and rear ends is greatly reduced, and the yield is improved. That is, the volume of the front end portion and the rear end portion that are removed without being subjected to shearing in the formed shear imparting molded body is the cross-sectional area of the material passage and the length of the molding material in the corner in the moving direction. It is calculated by the product of

  The length in the direction of movement of the molding material at this corner is approximately equal to the length of one side of the plane that is a diagonal line connecting the point on the inner corner side ridge line and the point on the outer corner side valley line. Will be equal. Therefore, in order to improve the yield of the shear-imparting molded body, the length in the moving direction described above is shortened, in other words, the area of the portion orthogonal to the ridge line at the corner is reduced, or the point on the ridge line is It is effective to shorten the line connecting the points on the valley line. For this reason, the cross-sectional shape of the material passage is formed in a rectangle in which the length in the direction along the ridgeline at the corner of the material supply port side portion and the material extrusion port side portion is longer than the length in the direction perpendicular to the ridgeline. Thus, the yield can be improved.

  Moreover, since the length in the direction orthogonal to the ridgeline at the corner in the cross section of the material passage is shortened, the molding material passing through the inner portion (ridgeline side portion) of the corner and the outer portion of the corner (valley line side) The difference generated in the shear applied to the molding material passing through the part) is reduced, and a shear-applied molded body in a substantially uniform state is obtained. Further, the predetermined angle of the material extrusion port side portion with respect to the material supply port side portion in the material passage may be less than 180 degrees, but is preferably an angle in the range of 60 degrees to 120 degrees.

Further, a shear imparting equipment according to the present invention, the application of back pressure in the shear applying step, performs by the backpressure punch moveable material extrusion port side portion than the corner portions of the material passage, back pressure punch The back pressure punch is provided with a stopper for preventing entry into the corner portion of the material passage. According to this, it can prevent that the molding material at the time of low density by back pressure is crushed.

Another feature of the configuration of the shear imparting device according to the present invention is a material supply step, after subjected supercharges BiTe-based thermoelectric device material into the material path, filled with argon gas was evacuated through the material passage There is to make it.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a shearing device A used in the shearing method according to the present invention. This shearing device A is composed of a mold 10 and a pressurizing apparatus 20 assembled to the mold 10. The mold 10 includes a lower mold 11 and an upper mold 12 made of an alloy containing titanium and iron, and a material path bent into an L shape including a material supply path 13 and a material extrusion path 14 therein. 15 is formed.

  The angle at which the material supply passage 13 and the material extrusion passage 14 intersect is set to 90 degrees, and the intersecting portion that is a rectangular parallelepiped is the corner portion 16 of the present invention. 2 shows the material supply passage 13 and the material extrusion passage 14 formed in the upper mold 12, and the cross-sectional shapes of the material supply passage 13 and the material extrusion passage 14 (the material supply port 13a of the material supply passage 13 and the material supply passage 13). The material extruding passage 14 has the same shape as the material extruding port 14a), the length of the long side 17 is set to 4 cm, and the length of the short side 18 is set to 1 cm.

  The pressure device 20 includes a drive unit 21 and a pressure punch 23 as a pressure member of the present invention connected to the drive unit 21 via a rod 22. The pressure punch 23 is a drive unit. The drive of 21 moves the material supply passage 13 up and down. That is, the lower end surface 23a of the pressure punch 23 is further raised above the material supply port 13a which is the upper end portion of the material supply passage 13 by the drive of the drive unit 21 to open the material supply port 13a. it can. Further, the lower end surface 23 a of the pressure punch 23 can be lowered to the position of the ridge line portion 16 a on the inner corner side at the corner portion 16 where the material supply passage 13 and the material extrusion passage 14 intersect.

  The pressurizing device 20 is also provided with a back pressure punch 24 that moves back and forth in the left and right directions in the material extruding passage 14 by driving of a driving unit (not shown). The back pressure punch 24 applies a small pressure to the molding material 25 (see FIG. 3) extruded into the material extruding passage 14, thereby imparting better shear to the molding material 25. Can be done. In particular, when the molding material 25 is a powder or a granular material, there is a great effect in maintaining the shape of the molding material 25 supplied first without protruding from the corner portion 16. The back pressure punch 24 can further recede from the material extrusion port 14a of the material extrusion passage 14 to open the material extrusion port 14a, and can enter the position of the ridge line portion 16a of the corner portion 16. it can.

  The shearing device A is installed in a vacuum chamber that can be depressurized. In addition to the devices described above, an argon gas supply device for supplying argon gas into the vacuum chamber, a mold 10 and the like. A heating device and a control device (not shown) are also provided. Then, under the control of the control device, each device such as the pressurizing device 20 is automatically driven and controlled according to the setting input in advance to the control device.

  Next, a method for forming a shearing formed body made of a powder material using the shearing apparatus A configured as described above will be described. Here, an example of a thermoelectric element used for the thermoelectric module will be described. When forming the shearing imparted molded body, first, a powder material for a thermoelectric element is manufactured. In this case, for example, a raw material for forming an N-type thermoelectric element is weighed to prepare a material having a ratio of Bi2Te2.7Se0.3. Next, this material is vacuum-sealed in a quartz tube, and the material sealed in the quartz tube is rocked and melted while being heated at a temperature of 650 ° C. to solidify.

  Then, the solidified material is heated to 800 ° C. in an argon atmosphere and formed into a foil using a single roll liquid quenching apparatus. In this foil formation, the melted material is dropped on the peripheral surface of a cooling roll that rotates at high speed, whereby the foil is rapidly cooled to form a foil. The foil piece material thus obtained is deoxygenated by heating to 400 ° C. in a hydrogen atmosphere to obtain a molding material 25 for a thermoelectric element made of a powder material. As a molding material in this case, a powder material obtained by a twin roll quenching apparatus or an atomizing method or a coagulated crushed powder may be used. Moreover, you may use what these formed temporarily with cold press, normal pressure sintering, hot press, CIP, HIP, etc.

  Next, the drive unit 21 of the pressurizing device 20 is driven to raise the pressurizing punch 23 above the material supply port 13 a, open the material supply port 13 a, and connect the back pressure punch 24 to the ridge line portion of the corner portion 16. Enter the position 16a. Then, the molding material 25 is put into the material supply passage 13 from the material supply port 13a. In this case, the molding material 25 is filled in the material supply passage 13 so that the foil pieces constituting the molding material 25 are stacked in a tilted state. Next, after evacuating and depressurizing the inside of the vacuum chamber, the argon gas supply device is activated to fill the vacuum chamber with argon gas. Then, after the heating device is turned on and the temperature in the vacuum chamber is raised to 450 ° C., the pressurizing device 20 is driven.

In this case, a back pressure of 50 kgf / cm ^{2 is applied to} the back pressure punch 24 in the direction of the corner 16, and in this state, the pressure punch 23 of the pressure device 20 is moved in the direction of arrow a in FIG. And descend at a speed of 0.3 mm / min. As a result, the molding material 25 moves in the direction of the arrow b while being compressed by receiving the back pressure of the back pressure punch 24. When the molding material 25 passes through the corner portion 16, a shearing force is applied, so that the molding material 25 is further enhanced in orientation and densified. This also increases the hardness of the molding material 25.

  Then, the pressure punch 23 is lowered until the lower end surface 23a reaches the ridge line portion 16a of the corner portion 16, while the molding material 25 is molded into a plate-like shear imparting molded body having a rectangular cross section. As a result, the material extruding passage 14 moves toward the material extruding port 14a. During this extrusion process, the front end surface 24a of the back pressure punch 24 gradually recedes from the position of the ridge line portion 16a of the corner portion 16 toward the material extrusion port 14a. Here, the pressure punch 23 is prevented from advancing below the position of the ridge line portion 16 a of the corner portion 16.

  As a result, the cross-sectional shape of the formed shear-imparting molded body is constant from the front end to the rear end. Further, the back pressure punch 24 is not advanced forward from the position of the ridge line portion 16 a of the corner portion 16. Thereby, the back pressure of the back pressure punch 24 prevents the molding material 25 at the time of low density from being crushed. For example, a stopper may be provided on the back pressure punch 24.

  Next, the shear-imparting molded body 27 formed as shown in FIG. 4 is taken out from the mold 10, and the front end portion 27a and the rear end portion 27b shown in FIG. To do. Then, the remaining shearing molded body 27c is cut in a direction orthogonal to the longitudinal direction (extrusion direction) to form a plurality of plate-like bodies having a predetermined thickness. Next, nickel plating is applied to both cut surfaces of the cut plate-like body, and this is further cut so that the nickel-plated surfaces become both end surfaces to form a rectangular parallelepiped N-type thermoelectric element. In combination with a P-type thermoelectric element such as Bi0.4Sb1.0Te3 obtained in the same manner, a thermoelectric module is obtained by bonding both plated surfaces of this thermoelectric element to electrodes provided on a pair of upper and lower substrates. .

Next, with respect to the yield in the shear imparting molded body 27 obtained by the shear imparting treatment, the shear imparting molded body 28 having a circular sectional shape shown in FIG. 5 and the shear imparting molded body 29 having a square sectional shape shown in FIG. Compared with the yield. In this case, the shear-imparting molded body 28 was set to have a radius of 1.128 cm, a cross-sectional area of 4 cm ² and a length of 10 cm. In addition, the shear-imparting molded body 29 was set to 2 cm in length and width, a cross-sectional area of 4 cm ² , and a length of 10 cm. As a result, each of the shear-imparted molded bodies 27, 28, 29 is a molded body having a cross-sectional area of 4 cm ² , a length of 10 cm, and a volume of 40 cm ³ .

In this case, in the shear imparting molded body 27, the volume of the front end portion 27a and the rear end portion 27b to be removed is 4 cm ³ which is the product of the cross-sectional area of 4 cm ² and the length of 1 cm, respectively. The volume is 8 cm ³ . Therefore, the overall volume yield is 80%. Further, in the shearing imparted molded body 28, the volume of the front end portion 28a and the rear end portion 28b to be removed is a product of a cross-sectional area of 4 cm ² and a length (substantially equal to the diameter) of 2.256 cm, respectively. 024Cm ^3, and the volume of the portion removed is the 18.048cm ^3. Therefore, the overall volume yield is 55%.

Further, in the shearing imparted molded body 29, the volume of the front end portion 29a and the rear end portion 29b to be removed is 8 cm ³ , which is the product of the cross-sectional area of 4 cm ² and the length of 2 cm, respectively. Is 16 cm ³ . Therefore, the overall volume yield is 60%. From this result, the yield of the shear imparting molded body 27 was the best, the yield of the shear imparting molded body 29 was the best, and the worst yield was the shear imparting molded body 28 having a circular cross-sectional shape. I understand.

  Next, a shear imparting molded body having a square cross-sectional shape with a side length of 2 cm is molded as a comparative example, and the L-shaped molds in the shear imparting molded body and the shear imparting molded body 27 of this comparative example are formed. The electrical resistivity of each part from the part which passed the inner peripheral side of the bending part to the part which passed the outer peripheral side was compared. The result is shown in FIG. That is, in the figure, the black circles indicate the measurement position and electrical resistivity of the shear-applying molded body of the comparative example, and the white circles indicate the measurement position and electrical resistivity of the shear-applying molded body 27. From this result, it can be seen that the electrical resistivity is the smallest at the portion passing through the inner peripheral side of the L-shaped bent portion and the largest at the portion passing through the outer peripheral side.

And about the part which passed between the inner peripheral side and the outer peripheral side, it has changed so that the electrical resistivity of the part from an inner peripheral side to an outer peripheral side may become large gradually. Therefore, as the shear-imparted molded body 27 has a smaller thickness with respect to the width, the overall electrical resistivity can be reduced and the difference can be reduced. According to the result shown in FIG. 7, in the shear imparted molded body of the comparative example, the difference in electrical resistivity between the inner periphery and the outer periphery is 0.9 × 10 ⁻⁵ Ωm, whereas in the shear imparted molded body 27 0.3 × 10 ⁻⁵ Ωm. From this result, it can be seen that as the thickness is reduced with respect to the width, a better shear-imparting molded body is obtained.

  Thus, according to the shearing device A according to the present embodiment, the length of the cross section of the material passage 15 including the material supply passage 13 and the material extrusion passage 14 in the direction along the ridge line portion 16a of the corner portion 16 is the same. The rectangular shape is longer than the length in the direction orthogonal to the ridge line portion 16a. For this reason, the yield of the molded shear imparting molded body 27 and the like is greatly improved as compared with the yield of the shear imparting molded bodies 28 and 29 having a circular or square cross-sectional shape.

  In this case, since the length between the ridge line portion 16a and the valley line portion 16b of the corner portion 16 is shortened, the molding material 25 (or shearing molding) passing through the ridge line portion 16a side portion of the corner portion 16 is performed. The difference in shear deformation imparted to the body portion) and the molding material 25 (or the shear imparting molded body portion) passing through the valley line 16b side portion of the corner portion 16 is reduced. As a result, the shear-imparted molded body 27 in a substantially uniform state is obtained. Further, by performing the shearing treatment, the obtained shearing molding 27 can be improved in orientation and densified, thereby increasing the hardness. As a result, a high-strength material can be obtained from the shear imparting molded body 27.

  FIG. 8 shows a shearing device B according to another embodiment of the present invention. In the shearing device B, the material supply passage 31 and the material extrusion passage 32 formed in the mold 30 are formed in the same rectangular shape as the cross-sectional shape of the material passage 15 of the shearing device A, and the material supply The angle of the corner 36 where the passage 31 and the material extrusion passage 32 intersect is set to approximately 120 degrees. The pressure punch 43 of the pressure device 40 can enter the material supply passage 31 up to the ridge 36a of the corner 36 where the material supply passage 31 and the material extrusion passage 32 intersect. It is possible to enter the material extrusion passage 32 up to the ridge line portion 36 a of the corner portion 36. About the structure of the other part in this shear provision apparatus B, it is the same as the shear provision apparatus A mentioned above.

  Since it comprised in this way, the shearing force given to the molding material 25 by the shearing process using this shearing application apparatus B is the shearing force given to the molding material 25 by the shearing process using the shearing application apparatus A. It becomes small compared. Therefore, when the molding material 25 laminated in advance with good orientation is subjected to a shearing process, or when the molding material formed on a molded body having a relatively high density is subjected to a shearing process, an appropriate shearing process can be performed. Moreover, the moving speed of the pressure punch 43 can be increased to perform the processing in a short time. About the other effect, it is the same as that of the shear provision apparatus A mentioned above.

  In each of the embodiments described above, powder, granules, and plates are used as the molding material. However, as the molding material, a molded body obtained by temporarily sintering the powder or granules may be used as the material. Good. Further, as the molding material, not only a molding material for forming a thermoelectric element but also a molding material or a ceramic material for forming a magnetic body can be used.

  Good results can also be obtained by changing the orientation so that the direction of shear applied to the molding material changes each time the material supply process and shearing process are performed, and supplying the molding material to the material passage. Is obtained. In this shearing application method, even if there is a difference in performance between the molding material that has passed the inner corner side of the corner and the molding material that has passed the outer corner side of the corner, When the shearing treatment is performed, the difference is reversed, so that they are canceled out each other, and as a whole, the uniform shearing shaped product is obtained each time the treatment is repeated. As a result, a shear-imparted molded article having better orientation and higher density can be obtained.

It is sectional drawing which shows the outline of the shear provision apparatus used by one Embodiment of this invention. It is a partial cross section perspective view which shows the material channel | path provided in the upper mold | type with which the shear provision apparatus of FIG. 1 is provided. It is sectional drawing which shows the direction to which a molding material moves in the material channel | path provided in the metal mold | die. It is a perspective view which shows the shear provision molded object obtained by embodiment of this invention. It is a perspective view which shows the shear provision molded object by which the cross-sectional shape was formed circularly. It is a perspective view which shows the shear provision molded object by which the cross-sectional shape was formed in the square. It is the graph which compared the electrical resistivity of the shear provision molded object of embodiment, and the shear provision molded object of a comparative example. It is sectional drawing which shows the shear provision apparatus used in other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mold, 13 ... Material supply path, 14 ... Material extrusion path, 15 ... Material path, 16 ... Corner | angular part, 16a, 36a ... Ridge line part, 17 ... Long side, 18 ... Short side, 20 ... Pressurization apparatus, DESCRIPTION OF SYMBOLS 21 ... Drive part, 23, 43 ... Pressure punch, 25 ... Molding material, 27 ... Shear provision molded object, A, B ... Shear provision apparatus.

Claims (2)

Shear for forming a shear-giving molded body by pressing and moving a foil-like BiTe-based thermoelectric material from the material supply port side to the material extrusion port side of the material passage having a bent corner. A grant method,
The length of the passage cross section perpendicular to the moving direction of the BiTe-based thermoelectric element material on both the material supply port side and the material extrusion port side of the material passage is in the direction along the ridge line of the corner portion. A material supply step of supplying the BiTe-based thermoelectric element material in a stacked manner from the material supply port of the material passage to a shearing device formed into a rectangle longer than the length in the direction orthogonal to
When the BiTe thermoelectric element material supplied to the material passage is pressurized and moved from the material supply port side and a back pressure is applied, and the BiTe thermoelectric element material passes through the corner portion. for example Bei and the shear applying step to shear deformation,
The application of back pressure in the shearing application step is performed by a back pressure punch movable at a material extrusion port side portion with respect to a corner portion of the material passage, and the back pressure punch enters the corner portion of the material passage. A shearing application method comprising a stopper for preventing the back pressure punch provided on the back pressure punch . In the material supply step, after supplying the BiTe-based thermoelectric device material into the material passage, shear imparting method according to 請 Motomeko 1 is filled with argon gas and exhausting the material passage.

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