Patent Description:
As a die support mechanism, there is known a mechanism that supports a blanking die for punching out a blank from a sheet metal (see Patent Document <NUM>, for example).

By the way, the above die support mechanism or a support portion of the blanking punch corresponding to the die support mechanism is provided with a position adjustment mechanism, and a centering adjustment for aligning the center of the blanking punch and the center of a punch hole is performed before continuous operation of continuously punching out blanks. However, there is a case where the center of the blanking punch and the center of the punch hole gradually deviate from each other due to some cause such as thermal deformation during continuous operation, and there may be caused a failure that the blanking punch is pressed against an opening edge of the punch hole; therefore, there is a demand for development of a technique that reduces the occurrence of such failure.

A die support mechanism according to one aspect made to solve the above problem includes: a die holding member including a slit that horizontally passes through the die holding member, wherein a lower side of the die holding member with respect to the slit forms a die holding base configured to hold a blanking die having a punch hole, an upper side of the die holding member with respect to the slit forms a ceiling portion having a ceiling hole concentric with the punch hole, a part of a sheet metal inserted in the slit is punched out as a blank by a blanking punch descending to the punch hole through the ceiling hole, and the ceiling portion separates the sheet metal from the ascending blanking punch; a support base configured to support the die holding member in a horizontally slidable manner; and a guide portion formed on an inner surface of the ceiling hole and configured to come into sliding contact with the blanking punch and to slide the die holding member to a position where the punch hole is centered on the blanking punch.

Hereinafter, a transfer press machine <NUM> according to a first embodiment of the present invention will be described with reference to <FIG>. As illustrated in <FIG>, the transfer press machine <NUM> includes a plurality of punches (see reference signs <NUM>, <NUM>, and 25X in <FIG>) laterally arranged in a row at a lower end part of a ram <NUM> supported by a support frame <NUM> in a vertically movable manner. Hereinafter, an arrangement direction of the plurality of punches is referred to as a "lateral direction H1", and a horizontal direction perpendicular to the lateral direction H1 is referred to as a "front-back direction H2". In addition, the side of the transfer press machine <NUM> shown in <FIG> is referred to as a "front side", and the side opposite to the front side is referred to as a "rear side". In addition, the right side of the transfer press machine <NUM> as viewed from the front side is simply referred to as a "right side", and the side opposite to the right side is simply referred to as a "left side".

The leftmost punch, of the plurality of punches at the lower end part of the ram <NUM> is a blanking punch <NUM> having a cylindrical shape as illustrated in <FIG>, and houses a lower end part of a drawing punch <NUM> therein. The blanking punch <NUM> and the drawing punch <NUM> constitute a part of a cylindrical workpiece generation device <NUM> included in the transfer press machine <NUM>. As illustrated in <FIG>, the blanking punch <NUM> punches out a blank W2 from a sheet metal W1, and as illustrated in <FIG>, the drawing punch <NUM> forms the blank W2 into a cylindrical workpiece W3. That is, the cylindrical workpiece W3 is generated from the sheet metal W1 by the cylindrical workpiece generation device <NUM>.

As illustrated in <FIG>, a plurality of punches other than the leftmost and rightmost punches in the ram <NUM> are additional-machining punches <NUM>, and a plurality of additional-machining dies <NUM> corresponding to the additional-machining punches <NUM> are provided in a support block <NUM> below the ram <NUM>. Then, each additional-machining punch <NUM> presses the cylindrical workpiece W3 into a forming hole (not illustrated) of its corresponding additional-machining die <NUM>, thereby drawing or ironing the cylindrical workpiece W3. The cylindrical workpiece W3 having been pushed into each forming hole is pushed out above the forming hole while being sandwiched between a knockout pin (not illustrated) and the additional-machining punch <NUM>, and is pulled out from the additional-machining punch <NUM> by a cylindrical workpiece stripper <NUM> fitted to each additional-machining punch <NUM>. The cylindrical workpiece W3 disposed above each forming hole is conveyed to above the forming hole on its right side by a transfer device <NUM>. This operation is repeated, and the cylindrical workpiece W3 is additionally machined a plurality of times by the plurality of additional-machining punches <NUM> and additional-machining dies <NUM>. The rightmost punch in the ram <NUM> is a shake-off punch 25X, and the cylindrical workpiece W3 conveyed by the transfer device <NUM> is shaken off to a discharge path (not illustrated). The cylindrical workpiece W3 fallen in the discharge path is collected in a collection box (not illustrated).

As illustrated in <FIG>, the above transfer device <NUM> has the following structure. A plurality of pairs of fingers <NUM> facing each other in the front-back direction H2 are supported by a pair of support rails <NUM> extending in the lateral direction H1 such that the fingers <NUM> can approach and separate from each other, and the fingers <NUM> are biased toward each other by coil springs (not illustrated). Then, the plurality of pairs of fingers <NUM> grip the cylindrical workpieces W3 and move the cylindrical workpieces W3 from respective ones of the additional-machining dies <NUM> to the additional-machining dies <NUM> on the right side thereof to hand over the cylindrical workpieces W3 to the additional-machining punches <NUM>, whereby the cylindrical workpieces W3 are intermittently conveyed to the right side in the lateral direction H1.

Note that a space between the blanking punch <NUM> and the leftmost additional-machining punch <NUM> is a so-called dummy stage having no punch or die, and the cylindrical workpiece W3 conveyed to the dummy stage by the transfer device <NUM> is temporarily held by being sandwiched by a knockout pin (not illustrated) and a lower surface of a support base <NUM> (to be described later) from the upper and lower directions.

The ram <NUM>, the transfer device <NUM>, the plurality of knockout pins, and the plurality of workpiece strippers <NUM> are driven by the same drive source. Specifically, as illustrated in <FIG>, an upper shaft <NUM> and a lower shaft <NUM> extending in the lateral direction H1 are respectively rotatably supported at an upper part and a lower part of the support frame <NUM>, and a side shaft <NUM> extending in the vertical direction is rotatably supported on the left side of the support frame <NUM>. Then, a bevel gear <NUM> at an upper end part of the side shaft <NUM> and a bevel gear <NUM> at one end of the upper shaft <NUM> are gear-connected to each other, and a lower end part of the side shaft <NUM> and one end part of the lower shaft <NUM> are connected to each other with a gear (not illustrated) incorporated in a gear box <NUM>, so that the upper shaft <NUM>, the side shaft <NUM>, and the lower shaft <NUM> are rotationally driven by a common drive source.

The ram <NUM> moves up and down by receiving power from a pair of cams 13A that rotate integrally with the upper shaft <NUM>, and the plurality of knockout pins move up and down by receiving power from a plurality of cams (not illustrated) that rotate integrally with the lower shaft <NUM>. The plurality of workpiece strippers <NUM> move up and down by receiving power from a plurality of cams (not illustrated) on the lower shaft <NUM> via a link mechanism (not illustrated) disposed behind the support block <NUM>. In addition, a cam 14A is also integrally rotatably provided at an intermediate part of the side shaft <NUM>. Then, the cam 14A is housed between a pair of communication bars (not illustrated) inserted between one ends of the pair of support rails <NUM> described above and between positions near the one ends, and this arrangement reciprocally moves the pair of support rails <NUM> in the lateral direction H1 in synchronization with a lifting operation of the ram <NUM>. Note that the ram <NUM>, the transfer device <NUM>, the plurality of knockout pins, and the plurality of workpiece strippers <NUM> may be driven by different drive sources, or, for example, only the plurality of workpiece strippers <NUM> may be driven by a different drive source.

Hereinafter, a configuration of the cylindrical workpiece generation device <NUM> will be described in detail. <FIG> illustrates the blanking punch <NUM>, the drawing punch <NUM>, and the die support mechanism <NUM>, which are main parts of the cylindrical workpiece generation device <NUM>. As illustrated in <FIG>, the drawing punch <NUM> is structured such that a punch main body portion 35B having a columnar shape whose outer diameter is larger than the diameter of a shaft portion 35A having a circular cross-section is fixed to the lower end of the shaft portion 35A. A corner part where a lower surface and a side surface of the punch main body portion 35B intersect is chamfered in an arc shape. In the present embodiment, the punch main body portion 35B has, for example, a flat shape in the vertical direction, but does not need to be flat.

As illustrated in <FIG>, the blanking punch <NUM> includes in order from the top, for example, an upper end columnar portion 31C, a first prismatic portion 31D, a second chamfered prismatic portion 31E, and a punch main body portion 31F (see <FIG>). The upper end columnar portion 31C protrudes from the center of an upper surface of the first prismatic portion 31D. The second chamfered prismatic portion 31E has a shape in which corner parts of the first prismatic portion 31D are chamfered to have a chamfering width wider than a chamfering width of the first prismatic portion 31D. The punch main body portion 31F (see <FIG>) has a substantially columnar shape. Note that the blanking punch <NUM> only needs to include the punch main body portion 31F at a lower end part, and an upper part of the blanking punch <NUM> with respect to the punch main body portion 31F may have any shape. The blanking punch <NUM> does not need to include the upper end columnar portion 31C, the first prismatic portion 31D, or the second chamfered prismatic portion 31E described above.

In detail, as shown in <FIG>, in the punch main body portion 31F, for example, a lower side of the punch main body portion 31F with respect to an intermediate part in the vertical direction is slightly reduced stepwise in diameter such that the upper side forms a large diameter portion <NUM> and the lower side forms a small diameter portion <NUM>. In addition, as illustrated in <FIG>, a step surface 31J between the large diameter portion <NUM> and the small diameter portion <NUM> has, for example, a quarter arc shape whose radius is the same as the difference between the radius of the large diameter portion <NUM> and the radius of the small diameter portion <NUM>, and an upper end part of the step surface 31J is continuous with the large diameter portion <NUM>. In addition, a corner part between the lower surface <NUM> of the blanking punch <NUM> and a side surface of the punch main body portion 31F (in more detail, the side surface of the small diameter portion <NUM>) is an edge portion <NUM>, where both the lower surface <NUM> and the side surface of the punch main body portion 31F are orthogonal to each other and forms a sharp edge. The step surface 31J does not need to be the above-described quarter arc shape whose diameter is the difference between the radius of the large diameter portion <NUM> and the radius of the small diameter portion <NUM>, and may have an arc shape of any size or a tapered shape.

As shown in <FIG>, the blanking punch <NUM> has a cylindrical shape as described above, and the inside of the blanking punch <NUM> has, for example, a small-diameter hole portion 31A at an upper end part, and the part other than the upper end part is a large-diameter hole portion 31B. Then, the shaft portion 35A of the drawing punch <NUM> passes through the small-diameter hole portion 31A in a linearly movable manner, and the punch main body portion 35B of the drawing punch <NUM> is housed in the large-diameter hole portion 31B.

As illustrated in <FIG>, while the blanking punch <NUM> is fixed to the ram <NUM> and moves up and down together with the ram <NUM>, the drawing punch <NUM> moves up and down by receiving power from, for example, a lever <NUM> having a seesaw shape rotatably supported by the support frame <NUM>.

Specifically, one end part of the lever <NUM> is hinge-connected to an upper end part of the drawing punch <NUM> movably in the lateral direction H1. A cam follower (not illustrated) protruding in a direction toward the rotation axis is provided at the other end part of the lever <NUM>. The cam follower is engaged with a cam groove 15A in an outer peripheral surface of a columnar body <NUM> that rotates integrally with the side shaft <NUM>. In the initial stage where the blanking punch <NUM> descends, the punch main body portion 35B of the drawing punch <NUM> is housed in the blanking punch <NUM>, for example, and after the blanking punch <NUM> reaches a bottom dead center, the punch main body portion 35B of the drawing punch <NUM> appears below from the blanking punch <NUM> and descends to reach the bottom dead center.

The blanking punch <NUM> and the drawing punch <NUM> of the present embodiment both have a circular planar cross-section, but may have an elliptical or oval planar cross-section, and the cylindrical workpiece generation device <NUM> may generate an elliptical or oval cylindrical workpiece. The drawing punch <NUM> may be configured to operate by receiving power from a power source different from the ram <NUM>.

As illustrated in <FIG>, the die support mechanism <NUM> has, for example, a structure in which a die holding member <NUM> is supported by a support base <NUM>. As illustrated in <FIG>, the die holding member <NUM> has a slit <NUM> passing through in the front-back direction H2. For example, a die holding base <NUM>, which is on the lower side with respect to the slit <NUM>, holds a blanking die <NUM> and a drawing die <NUM>. A ceiling portion <NUM>, which is on the upper side with respect to the slit <NUM>, has a ceiling hole <NUM> through which the blanking punch <NUM> and the drawing punch <NUM> pass.

In detail, as a whole, the die holding base <NUM> has a rectangular plate shape whose planar shape is horizontally long, and the whole ceiling portion <NUM> has, for example, a rectangular plate shape that has the same size as the die holding base <NUM> in the lateral direction H1 and that is smaller than the die holding base <NUM> in the front-back direction H2. Further, on both end edges in the lateral direction H1 on a lower surface of the ceiling portion <NUM>, for example, there are provided a pair of rectangular protrusions 43T having a rectangular cross-section and extending in the front-back direction H2. Then, for example, the ceiling portion <NUM> is disposed at the center of the die holding base <NUM> in the front-back direction H2, the ceiling portion <NUM> is fixed to the die holding base <NUM> with a plurality of bolts vertically penetrating the pair of rectangular protrusions 43T and a pair of pins <NUM>, so that the above-described slit <NUM> is formed between the upper surface of the die holding base <NUM> and the lower surface of the ceiling portion <NUM>. Instead of the pair of rectangular protrusions 43T of the ceiling portion <NUM>, a pair of rectangular protrusions may be provided at both ends of the die holding base <NUM> in the lateral direction H1.

A central part of the ceiling portion <NUM> in the lateral direction H1 forms, for example, a thick portion 43U that is thickened stepwise upward, and the ceiling hole <NUM> vertically passes through the thick portion 43U. The ceiling hole <NUM> has, for example, a circular cross-section. As illustrated in <FIG>, an upper side of the ceiling hole <NUM> with respect to a middle position in the vertical direction forms, for example, a tapered guide portion 44A whose diameter increases upward, and the lower side forms, for example, a straight guide portion 44B having the same inner diameter as the lower end of the tapered guide portion 44A and having a uniform inner diameter (reference sign D4 in <FIG>) wholly.

As illustrated in <FIG>, in the die holding base <NUM>, there is formed a die housing hole <NUM> coaxially with the ceiling hole <NUM>. For example, a diameter of the die housing hole <NUM> is reduced stepwise at a middle position in the vertical direction, a step surface of the step forms a horizontal die support surface 46B, and the blanking die <NUM> and the drawing die <NUM> are fitted in a large diameter portion 46A, which is on the upper side with respect to the die support surface 46B, with the drawing die <NUM> positioned under the blanking die <NUM>. Furthermore, the blanking die <NUM> and the drawing die <NUM> are fixed to the die holding base <NUM> with, for example, a plurality of bolts (not illustrated) vertically penetrating therethrough.

The drawing die <NUM> has a disk shape and has a circular drawing hole 36A at the center of the disk shape. In addition, a corner part where an inner side surface of the drawing hole 36A and a horizontal upper surface 36B of the drawing die <NUM> intersect is a chamfered surface 36C having an arc shape. Furthermore, the drawing hole 36A has a smaller inner diameter than, for example, a small diameter portion 46C of the die housing hole <NUM>, which is below the die support surface 46B.

The blanking die <NUM> has, for example, a disk shape having the same outer diameter as the drawing die <NUM>, and includes, at its central part, a circular punch hole 32A larger than the drawing hole 36A. The upper surface 36B of the drawing die <NUM> is exposed at the lower end of the punch hole 32A. Further, for example, an annular protrusion 32T protrudes stepwise from an opening edge of the punch hole 32A on an upper surface 32B of the blanking die <NUM>. An upper surface 32C of the annular protrusion 32T is horizontal, and an inclined surface 32D is formed between the upper surface 32C and the upper surface 32B. A corner part between the upper surface 32C of the annular protrusion 32T and an inner surface of the punch hole 32A is, for example, an edge portion <NUM> at which the upper surface 32C and the punch hole 32A are orthogonal to each other and forms a sharp edge. Note that the annular protrusions 32T does not need to be provided.

As illustrated in <FIG>, on the upper surface of the die holding base <NUM>, a pair of upper surface grooves <NUM> extending in the front-back direction H2 are formed, for example, at two positions disposed between a pair of rectangular protrusions 43T and the die housing hole <NUM>. Each of the upper surface grooves <NUM> has a quadrangular cross-section, and, for example, a pair of support column insertion holes 42A vertically passing through the die holding base <NUM> are opened at positions near both ends in the longitudinal direction of a bottom surface of each upper surface groove <NUM>. Note that, for example, cutout portions 43A for avoiding interference with a tool for tightening bolts <NUM> (to be described later) to be inserted through the support column insertion holes 42A are formed at edge parts of the ceiling portion <NUM>.

For example, at both end parts, in a left-right direction, of a part of the die holding base <NUM> on the front side with respect to the ceiling portion <NUM>, there are formed a pair of pin holes 42P vertically passing through the die holding base <NUM>. Both the pin holes 42P are partially disposed in front of the slit <NUM>, for example.

As illustrated in <FIG>, the support base <NUM> has, in its upper surface, a receiving groove <NUM> having a rectangular groove structure extending in the lateral direction H1. Then, as illustrated in <FIG>, the die holding base <NUM> is received in the receiving groove <NUM>. In addition, as illustrated in <FIG>, for example, two pairs of support columns <NUM>, that is, four support columns <NUM> in total to be received in the support column insertion holes 42A of the die holding base <NUM> stand from a bottom surface of the receiving groove <NUM>. Furthermore, for example, a pair of beams <NUM> having a quadrangular cross-section and extending in the front-back direction H2 are placed on and fixed to upper surfaces of the pairs of support columns <NUM>, and the support columns of each pair are facing each other in the front-back direction H2.

In detail, as illustrated in <FIG>, the support columns <NUM> each have, for example, a cylindrical shape, and are fitted in circular recesses 55A formed in the bottom surface of the receiving groove <NUM>. Further, for example, female threaded holes 55B vertically pass through the center of the bottom surface of the corresponding recesses 55A. Furthermore, for example, counterbore holes 53Z are formed at two positions of each beam <NUM> immediately above the support columns <NUM>, and lower end parts of the bolts <NUM> having head portions received in the counterbore holes 53Z are tightened to the female threaded holes 55B described above, so that the beams <NUM> are fixed to the receiving grooves <NUM> together with the support columns <NUM>. Then, the die holding base <NUM> is held by the support base <NUM> with the beams <NUM> and the support columns <NUM>. Note that upper surfaces of the beams <NUM>, the upper surface of the die holding base <NUM>, and an upper surface of the support base <NUM> are disposed, for example, substantially flush with each other, but any one of the upper surfaces may be disposed higher than the other upper surfaces.

As illustrated in <FIG> and <FIG>, the support base <NUM> is provided with a through-hole <NUM> vertically passing through in a coaxial manner with the die housing hole <NUM> of the die holding base <NUM>. The through-hole <NUM> has, for example, an inner diameter substantially the same as the diameter of the small diameter portion 46C on the lower end part of the die housing hole <NUM>. In addition, the support base <NUM> is provided with a pair of recesses 54A that faces each other in the front-back direction H2 and is opened to an inner surface of the through-hole <NUM>. Furthermore, the pair of recesses 54A house a pair of workpiece strippers <NUM>, and the workpiece strippers <NUM> are biased toward such sides that the strippers <NUM> approach to each other.

As illustrated in <FIG>, for example, on each of both ends of the support base <NUM> in the front-back direction H2, there are provided a pair of fixing holes <NUM>. As illustrated in <FIG>, the support base <NUM> is placed on a pair of base portions <NUM> that are fixed to an upper surface of the support block <NUM> and face each other in the front-back direction H2. For example, the support base <NUM> is fixed by tightening base fixing bolts <NUM> having passed through the fixing holes <NUM> to threaded holes 24N of the base portion <NUM>. As a result, the entire support base <NUM> is held above the upper surface of the support block <NUM> with a space therebetween and the above-described transfer device <NUM> penetrates between the support base <NUM> and the support block <NUM>.

As illustrated in <FIG>, when the ram <NUM> is located at a top dead center, the above-mentioned blanking punch <NUM> is disposed at a position away upward from the ceiling portion <NUM> together with the drawing punch <NUM>. Then, in a state where the sheet metal W1 inserted through the slit <NUM> covers the punch hole 32A of the blanking die <NUM>, the blanking punch <NUM> passes through the ceiling hole <NUM> of the ceiling portion <NUM> and enters the punch hole 32A, so that a part of the sheet metal W1 is punched out as a blank W2 as illustrated in <FIG>. In detail, the sheet metal W1 is cut into a circular shape by the edge portion <NUM> of the blanking punch <NUM> and the edge portion <NUM> of the blanking die <NUM>, and the blank W2 is separated from the sheet metal W1. Then, the ram <NUM> reaches the bottom dead center when the lower surface <NUM> of the blanking punch <NUM> comes adjacent to the upper surface 36B of the drawing die <NUM>. An outer edge part of the blank W2 is sandwiched between the lower surface <NUM> of the blanking punch <NUM> and the upper surface 36B of the drawing die <NUM>.

The drawing punch <NUM> descends downward from the blanking punch <NUM> in a state where the outer edge part of the blank W2 is sandwiched between the blanking punch <NUM> and the drawing die <NUM>, and pushes the blank W2 into the drawing hole 36A to form a cylindrical workpiece W3 as illustrated in <FIG>.

The drawing punch <NUM> then descends to below the support base <NUM> together with the cylindrical workpiece W3, passes between the pair of workpiece strippers <NUM>, and reaches the bottom dead center when further entering between the pair of fingers <NUM> at the left end part of the transfer device <NUM> (see <FIG>). When the drawing punch <NUM> ascends, the cylindrical workpiece W3 is separated from the drawing punch <NUM> by the pair of workpiece strippers <NUM>. In addition, for example, the blanking punch <NUM> ascends prior to the drawing punch <NUM>, and at that time, the sheet metal W1 disposed outside the blanking punch <NUM> comes into contact with the ceiling portion <NUM> and is separated from the blanking punch <NUM>. Note that the blanking punch <NUM> and the drawing punch <NUM> may be configured to ascend at any timing. For example, the blanking punch <NUM> and the drawing punch <NUM> may be configured to ascend simultaneously after the drawing punch <NUM> reaches the bottom dead center.

The cylindrical workpiece W3 generated by the cylindrical workpiece generation device <NUM> as described above and passed to the pair of fingers <NUM> of the transfer device <NUM> is sequentially conveyed onto the plurality of additional-machining dies <NUM> via the dummy stage, and is additionally machined by the plurality of additional-machining punches <NUM> and the additional-machining dies <NUM> as described above.

The operation of punching out the blank W2 from the sheet metal W1 with the blanking punch <NUM> and the blanking die <NUM> is smoothly performed as long as a central axis of the blanking punch <NUM> and a central axis of the punch hole 32A coincide with each other, but there is a case where the central axis of the blanking punch <NUM> and the central axis of the punch hole 32A deviate from each other beyond an allowable range during continuous operation of the transfer press machine <NUM> for some reason. This causes a failure that the edge portion <NUM> of the blanking punch <NUM> hits the edge portion <NUM> of the opening edge of the punch hole 32A and is thus damaged (hereinafter, the failure is referred to as an "off-axis failure").

In order to prevent the off-axis failure, the cylindrical workpiece generation device <NUM> is provided with, for example, a floating mechanism, a guide mechanism, a positioning and fixing mechanism, and an origin adjustment mechanism. In the floating mechanism, there is provided a clearance in a part where the support base <NUM> holds the die holding member <NUM>. The support base <NUM> slidably supports the die holding member <NUM> in any desired horizontal direction within a range of the clearance. In the guide mechanism, the die holding member <NUM> is guided so as to move in a direction in which the central axis of the punch hole 32A coincides with the central axis of the blanking punch <NUM> by sliding contact between the die holding member <NUM> and the blanking punch <NUM>. In the positioning and fixing mechanism, the die holding member <NUM> is fixed at the origin position in a slidable range on the support base <NUM>. The origin adjustment mechanism is a mechanism for adjusting the position of the support base <NUM> with respect to the support block <NUM> such that the central axis of the blanking punch <NUM> and the central axis of the punch hole 32A coincide with each other within an allowable range in a state where the die holding member <NUM> is fixed to the origin position on the support base <NUM>. Hereinafter, specific configurations of such mechanisms will be described. Note that, for example, the cylindrical workpiece generation device <NUM> may include only a floating mechanism and a guide mechanism, may include a floating mechanism, a guide mechanism, and a positioning and fixing mechanism, or may include a floating mechanism, a guide mechanism, and an origin adjustment mechanism.

The positioning and fixing mechanism of the die support mechanism <NUM> of the present embodiment includes, for example, the above-described pair of pin holes 42P of the die holding member <NUM> illustrated in <FIG>, a pair of pin holes 51P of the support base <NUM> provided immediately below the pin holes 42P, and a pair of positioning pins <NUM>. Then, the positioning pins <NUM> are inserted into respective ones of pairs of vertically disposed pin hole 42P and pin hole 51P, and the die holding member <NUM> is two-dimensionally positioned in the horizontal direction with respect to the support base <NUM>. Furthermore, the position at which the die holding member <NUM> is thus positioned serves as the origin position of the die holding member <NUM> with respect to the support base <NUM>.

In addition, an upper part of each positioning pin <NUM> is increased in diameter, for example, in a stepped manner, is in contact with an opening edge of the corresponding pin hole 42P, and protrudes from the upper surface of the die holding base <NUM>. Furthermore, as illustrated in <FIG>, the upper parts of the pair of positioning pins <NUM> are both disposed at positions facing the slit <NUM> from the front-back direction H2. As a result, in a state where the pair of positioning pins <NUM> are attached, the sheet metal W1 interferes with the positioning pins <NUM> when the sheet metal W1 is inserted through the slit <NUM>, and it is possible to notice that the positioning pins <NUM> are left forgotten to be removed. That is, it is prevented that a continuous operation of the transfer press machine <NUM> is started while the die holding member <NUM> is still fixed to the support base <NUM>.

Note that the positioning and fixing mechanism may have the following structure, for example. At two positions on the die holding member <NUM> and at two positions on the support base <NUM>, there are provided such alignment surfaces that are disposed to be vertically flush with each other when the die holding member <NUM> is disposed at the origin position on the support base <NUM>. When each pair of alignment surfaces are fixed with a flat member being commonly applied to the pair of alignment surfaces, the die holding member <NUM> is fixed at the origin position on the support base <NUM>.

As illustrated in <FIG>, the floating mechanism has a structure in which, for example, a first clearance <NUM> having a predetermined dimension (for example, <NUM> to <NUM>) or more is formed along the entire circumferences between outer peripheral surfaces of all the support columns <NUM> and inner peripheral surfaces of all the support column insertion holes 42A in a state where the die holding member <NUM> is positioned at the origin position on the support base <NUM>. That is, the difference between a radius of the outer peripheral surfaces of the support columns <NUM> and a radius of the inner peripheral surfaces of the support column insertion holes 42A is the first clearance <NUM> of the predetermined dimension or more. In addition, in a state where the die holding member <NUM> is positioned at the origin position on the support base <NUM>, a clearance having a size equal to or larger than the first clearance <NUM> is formed, for example, between each beam <NUM> and a pair of inner side surfaces of the corresponding upper surface groove <NUM> and between the die holding member <NUM> and a pair of inner side surfaces of the receiving groove <NUM>. Furthermore, for example, a clearance (not illustrated) is provided between the lower surface of each beam <NUM> and a bottom surface of the corresponding upper surface groove <NUM>, so that the beam <NUM> does not press the die holding member <NUM> against the bottom surface of the receiving groove <NUM>. As a result, in a state where the pair of positioning pins <NUM> are removed, the die holding member <NUM> can slide with respect to the support base <NUM> in any desired horizontal direction within a range of the first clearance <NUM>.

Note that, in the present embodiment, the die holding member <NUM> at the origin position is disposed at the center of the movable range with respect to the support base <NUM>. However, in a case where the blanking punch <NUM> tends to be displaced to one side in a certain direction with respect to the punch hole 32A during continuous operation of the transfer press machine <NUM>, it is preferable that the die holding member <NUM> at the origin position be disposed to be displaced from the center of the movable range with respect to the support base <NUM> in accordance with the tendency.

As illustrated in <FIG>, the origin adjustment mechanism has the following structure, for example. A clearance having a size equal to or larger than the first clearance <NUM> is provided between the plurality of base fixing bolts <NUM> for fixing the support base <NUM> to the base portions <NUM> and the plurality of fixing holes <NUM> of the support base <NUM> through which the base fixing bolts <NUM> are passed. When all the base fixing bolts <NUM> are loosened, the support base <NUM> becomes slidable, and when the base fixing bolts <NUM> are tightened, the support base <NUM> is fixed at any desired position on the support block <NUM>. With this arrangement, the origin adjustment of the die support mechanism <NUM> is completed by the following procedure. The die holding member <NUM> is fixed at the origin position on the support base <NUM>, and all the base fixing bolts <NUM> are loosened. In this state, as illustrated in <FIG>, the blanking punch <NUM> is inserted into the punch hole 32A by a manual operation, so that the central axis of the blanking punch <NUM> and the central axis of the punch hole 32A coincide with each other. Then, all the base fixing bolts <NUM> are tightened, and the pair of positioning pins <NUM> are removed.

Note that the following structure can be considered as the origin adjustment mechanism. For example, the support base <NUM> is positioned and fixed to the base portions <NUM> with pins, keys, or the like, and, in this state, the blanking punch <NUM> is adjusted in position with respect to the ram <NUM>.

As illustrated in <FIG>, the guide mechanism includes as described above, for example: the tapered guide portion 44A and the straight guide portion 44B in the ceiling hole <NUM> of the die holding member <NUM>; and the large diameter portion <NUM>, the small diameter portion <NUM>, and the step surface 31J of the blanking punch <NUM>. Specifically, the difference between the radius (<NUM> × D3) of the upper end of the tapered guide portion 44A and the radius (<NUM> × D2) of the lower end of the blanking punch <NUM> is larger than the above-described first clearance <NUM>, which is the range in which the die holding member <NUM> is slidable with respect to the support base <NUM>. As a result, regardless of where the die holding member <NUM> is located in the slidable range with respect to the support base <NUM>, the blanking punch <NUM> enters the ceiling hole <NUM> without hitting the upper surface of the ceiling hole <NUM>.

As shown in <FIG>, before the blanking punch <NUM> enters the punch hole 32A (more specifically, immediately before or at the same time when the sheet metal W1 is sandwiched between the blanking die <NUM> and the blanking punch <NUM>), the lower end of the large diameter portion <NUM> of the blanking punch <NUM> passes through the tapered guide portion 44A of the ceiling hole <NUM> and enters the straight guide portion 44B, and the blanking punch <NUM> and the punch hole 32A are centered on each other. As a result, the blanking punch <NUM> enters thereafter the punch hole 32A without the edge portion <NUM> of the blanking punch <NUM> hitting the edge portion <NUM> of the punch hole 32A. For that purpose, a second clearance <NUM> that is the difference between the radius (<NUM> × D2) of the small diameter portion <NUM> of the blanking punch <NUM> and the radius (<NUM> × D5) of the punch hole 32A is larger than a third clearance <NUM> that is the difference between the radius (<NUM> × D1) of the large diameter portion <NUM> of the blanking punch <NUM> and the radius (<NUM> × D4) of the straight guide portion 44B of the ceiling hole <NUM>.

Note that the guide mechanism may have any structure as long as the blanking punch <NUM> is guided by the ceiling hole <NUM> so that the blanking punch <NUM> enters the punch hole 32A without the edge portion <NUM> of the blanking punch <NUM> hitting the edge portion <NUM> of the punch hole 32A. For example, the following configuration can be considered: a tapered portion corresponding to the tapered guide portion 44A is provided on the blanking punch <NUM>; or the entire inside of the ceiling hole <NUM> is configured to be the tapered guide portion 44A.

The configuration of the transfer press machine <NUM> of the present embodiment has been described above. Next, an action and effect of the transfer press machine <NUM> will be described. As illustrated in <FIG> and described above, the die support mechanism <NUM> of the transfer press machine <NUM> of the present embodiment includes the die holding member <NUM> through which the slit <NUM> passes in the front-back direction H2. In addition, a lower side of the die holding member <NUM> with respect to the slit <NUM> forms the die holding base <NUM> that holds the blanking die <NUM>, and an upper side with respect to the slit <NUM> forms the ceiling portion <NUM> having the ceiling hole <NUM> concentric with the punch hole 32A of the blanking die <NUM>. Then, the die holding member <NUM> is supported by the support base <NUM> in a horizontally slidable manner, and the tapered guide portion 44A and the straight guide portion 44B of the ceiling hole <NUM> are in sliding contact with the blanking punch <NUM>, so that the die holding member <NUM> slides to a position where the punch hole 32A is centered on the blanking punch <NUM>. As a result, even when the center of the blanking punch <NUM> and the center of the punch hole 32A are deviated from each other due to thermal deformation or the like, the deviation is eliminated before the blanking punch <NUM> enters the punch hole 32A, thereby suppressing a failure in which the blanking punch <NUM> hits the opening edge of the punch hole 32A as in the conventional art, and the durability of the blanking punch <NUM> and the blanking die <NUM> is therefore improved.

In addition, when the blank W2 is drawn into the cylindrical workpiece W3 by the drawing punch <NUM>, the blank W2 is stably held by the blanking punch <NUM>, so that the shape of the cylindrical workpiece W3 is also stabilized. Then, the transfer press machine <NUM> additionally machines the thus
generated cylindrical workpiece W3; therefore, the final shape of the cylindrical workpiece W3 is also stabilized.

In addition, since the support base <NUM> can be fixed after the punch hole 32A and the blanking punch <NUM> are centered on each other by sliding the support base <NUM> in the horizontal direction in a state where the die holding member <NUM> is fixed at the origin position on the support base <NUM>, it is possible to effectively use the slidable range of the die holding member <NUM> with respect to the support base <NUM>, and the slidable range can be accordingly narrowed so that the punching operation of the blank W2 can be stabilized.

Furthermore, since the pair of positioning pins <NUM> for positioning the die holding member <NUM> at the origin position on the support base <NUM> are disposed at such positions that the positioning pins <NUM> restrict insertion of the sheet metal W1 into the slit <NUM>, it is possible to prevent starting of punching of the blank W2 in a state where the pair of positioning pins <NUM> are left forgotten to be removed.

A cylindrical workpiece generation device 30X of the present embodiment includes, for example, a cylindrical portion 43V standing from a ceiling portion <NUM>, and the entire inside of a ceiling hole <NUM> inside the cylindrical portion 43V has a uniform inner diameter. That is, the inside of the ceiling hole <NUM> is the same as the inside of the straight guide portion 44B of the first embodiment. Furthermore, even when the blanking punch <NUM> reaches the top dead center, the large diameter portion <NUM> of the blanking punch <NUM> does not come out of the ceiling hole <NUM>. The other configurations are the same as the configurations of the first embodiment. The configuration of the present embodiment also achieves the same action and effect as in the first embodiment.

Note that, in the structure of the present embodiment, the same action and effect are achieved also in a case where an upper side of the ceiling hole <NUM> with respect to a middle position in the vertical direction serves as the tapered guide portion 44A and the lower side serves as the straight guide portion 44B.

The die support mechanism <NUM> of the above embodiment is part of the cylindrical workpiece generation
device <NUM> included in the transfer press machine <NUM>, but the die support mechanism <NUM> may be provided as part of a single cylindrical workpiece generation device not included in a transfer press machine.

The above die support mechanism <NUM> may be simply applied to a pressing machine for producing a blank.

Claim 1:
A die support mechanism (<NUM>) comprising:
a die holding member (<NUM>) including a slit (<NUM>) that horizontally passes through the die holding member (<NUM>), wherein
a lower side of the die holding member (<NUM>) with respect to the slit (<NUM>) forms a die holding base (<NUM>) configured to hold a blanking die (<NUM>) having a punch hole (32A),
an upper side of the die holding member (<NUM>) with respect to the slit (<NUM>) forms a ceiling portion (<NUM>) having a ceiling hole (<NUM>) concentric with the punch hole (<NUM>),
wherein, in use, a part of a sheet metal (W1) inserted in the slit (<NUM>) is punched out as a blank (W2) by a blanking punch (<NUM>) descending to the punch hole (32A) through the ceiling hole (<NUM>), and
the ceiling portion (<NUM>) separates the sheet metal (W1) from the ascending blanking punch (<NUM>);
a support base (<NUM>) configured to support the die holding member (<NUM>) in a horizontally slidable manner; and
a guide portion (44A, 44B) formed on an inner surface of the ceiling hole (<NUM>) and configured to come into sliding contact with the blanking punch (<NUM>) and to slide the die holding member (<NUM>) to a position where the punch hole (32A) is centered on the blanking punch (<NUM>).