JP4906677B2 - Closed forging device - Google Patents

Description

  The present invention relates to a closed forging device.

  Conventionally, closed forging has been used as a method for manufacturing a product having a complicated shape such as a bevel gear with high accuracy. In closed forging, a mold cavity space is defined by bringing one mold into contact with the other mold, and a product is formed by plastic deformation in the mold cavity space. In order to create such a sealed state, a hydraulic mechanism is generally used.

  When closed forging is performed in this way, a hydraulic mechanism is required, which causes a problem that the apparatus is enlarged. In addition, when the processing speed is increased, the supply of hydraulic pressure cannot catch up with the speed, and thus the productivity is low. Therefore, it is conceivable to lower the oil pressure in order to supply the oil pressure at a speed that matches the processing speed. However, if the oil pressure is lowered, a desired sealed state cannot be obtained, and the accuracy of the product is lowered.

In order to solve the above-described problems, a closed forging device that creates a mechanically sealed state without using a hydraulic mechanism is conceivable. In this closed forging device, a pair of dies composed of a die side die disposed in a die housing and a press side die are in contact with each other in the axial direction of the die. When being pushed, the pushing member on the punch side pushes the engaging member disposed in the die housing further into the die housing, so that the engaging member is reduced in diameter by the diameter reducing means, and is engaged across the pair of molds. (See Patent Document 1). According to this closed forging device, the sealing state of the engraving space formed from the pair of molds is enhanced by the engaging member, and desired closed forging can be performed.
Japanese Patent No. 3127124

  However, in the closed forging device as described above, when the engaging member is pushed up from the back of the die housing after the product is formed, the engaging member is in a predetermined position because of deterioration of a spring for pushing up the engaging member. The case where it does not return until is considered. Then, the next molding is started in a state where it is not engaged with the pushed-up die side mold at a predetermined position, and it is considered that a desired sealed state cannot be obtained or the mold is damaged. It is done.

  Accordingly, an object of the present invention is to solve the above-described problems and to provide a closed forging device that can obtain a desired closed state without damaging the mold.

In the forging closure device of the present invention, a movable mold that has a first mold and is movable in the axial direction and a fixed mold that has a second mold are arranged opposite to each other on the same axis, and the first mold And a closed forging device in which a die-sculpting space is formed by the second mold,
The first mold is formed with an uneven first uneven portion on the outer peripheral surface on the fixed mold side,
The second mold is formed with an uneven second uneven portion on the outer peripheral surface on the movable mold side,
An engagement mechanism including a plurality of divided pieces and a case for holding the divided pieces on the inner peripheral side is disposed on the outer peripheral side of the second mold,
The case has a tapered shape in which the inner peripheral surface has a smaller diameter from the movable mold side to the fixed mold side,
The split piece has a tapered shape in which the outer peripheral surface has a smaller diameter from the movable mold side to the fixed mold side, and the inner peripheral surface has a plurality of piece uneven parts that fit into the uneven parts of the first mold and the second mold. The at least one convex part that is formed and fits into the concave part of the second mold of the piece concave-convex part is a retaining part that projects inward from the other convex part,
The second mold and the divided piece are arranged so as not to be separated by the retaining portion,
The divided pieces move along the inner peripheral surface of the case, and the uneven portions of the divided pieces are fitted into the uneven portions of the first mold and the second mold.

  The dividing piece is characterized in that a regulating portion for regulating the movement of the dividing piece only in the axial direction is formed.

  The divided piece is characterized in that an outer peripheral surface that comes into contact with an inner peripheral surface of the case is formed in a straight line in a front view.

  The second mold and the case are each supported by a buffer mechanism so as to be movable in the axial direction.

  The retaining part of the split piece has a horizontal surface that is in contact with the recess of the second mold and is perpendicular to the axis of the closed forging device, and the projections other than the retaining part are located on the axis of the closed forging device. It has the taper surface which inclines toward, It is characterized by the above-mentioned.

  According to the closed forging device according to the feature of the present invention, the movable mold having the first mold and movable in the axial direction and the fixed mold having the second mold are arranged opposite to each other on the same axis. A closed forging device in which a mold engraving space is formed by a first mold and a second mold, wherein the first mold has an uneven first uneven portion formed on an outer peripheral surface on the fixed mold side, The mold has a concave-convex second concave-convex portion formed on the outer peripheral surface on the movable mold side, and includes a plurality of divided pieces on the outer peripheral side of the second mold and a case for holding the divided pieces on the inner peripheral side. The case has a tapered shape in which the inner peripheral surface has a small diameter from the movable mold side to the fixed mold side, and the divided piece has a tapered shape in which the outer peripheral surface has a small diameter from the movable mold side to the fixed mold side. In the shape, a plurality of piece irregularities that fit into the irregularities of the first mold and the second mold are formed on the inner peripheral surface. At least one convex part that fits into the concave part of the second mold is a retaining part that projects inward from the other convex part, and the second mold and the divided piece are not separated by the retaining part. Since the split piece moves along the inner peripheral surface of the case and the concave and convex portions of the split piece are fitted to the concave and convex portions of the first mold and the second mold, the split piece is the first mold. Since a desired arrangement state can always be maintained with respect to the mold and the second mold, a desired closed state is always obtained. Moreover, since the uneven | corrugated | grooved part of a 1st metal mold | die and a 2nd metal mold | die and the piece uneven | corrugated | grooved part of a division | segmentation piece fit in a predetermined state, a metal mold | die is not damaged.

  In addition, if the dividing piece is formed with a restricting portion that restricts the movement of the dividing piece only in the axial direction, the dividing piece moves only in the axial line without moving in the radial direction. And since the uneven | corrugated | grooved part of a 2nd metal mold | die and the piece uneven | corrugated | grooved part of a division | segmentation piece fit, a desired obstruction | occlusion state is obtained.

  In addition, when the outer peripheral surface that contacts the inner peripheral surface of the case is formed in a straight line when viewed from the front, the split piece comes into surface contact with the case, so that the split piece can receive a load on the entire surface that contacts the case. The service life is improved and the movement in the axial direction is stabilized.

  Further, when the second mold and the case are supported by the buffer mechanisms so as to be movable in the axial direction, the movement of the second mold and the case in the axial direction is stabilized by the elastic force.

  Further, the retaining portion of the split piece has a horizontal surface that is in contact with the concave portion of the second mold and is perpendicular to the axis of the closed forging device, and the convex portions other than the retaining portion are shafts of the closed forging device. When the tapered surface is inclined toward the center, the split piece is difficult to be removed from the second mold due to the horizontal surface of the retaining part of the split piece, and the convex parts other than the retaining part of the split piece are Since it is easy to fit in and out of the concave and convex portions of the first mold and the second mold, the split piece and the first mold and the second mold are smoothly fitted and separated, so that the desired shape can be obtained. Since the concave and convex portions of the first mold and the second mold and the piece concave and convex portions of the divided pieces are fitted in the state, a desired closed state is obtained.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  FIG. 1 shows a closed forging device according to an embodiment of the present invention and a manufacturing process of a product manufactured by the closed forging device. FIG. 1 is a sectional plan view showing a forging process of the product, and FIG. FIG. 3 is a partial cross-sectional plan view showing a state before the product is formed by the closed forging device, FIG. 3 is a partial cross-sectional plan view showing a state in the middle of the product forming by the closed forging device, and FIG. FIG. 5 is a plan view, FIG. 5 shows a divided piece, (A) is a plan view, (A) is a front view, and FIG. 6 is a front view of the case and the divided pieces.

  A closed forging device according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a process of forging a bevel gear W4 used for a power transmission connecting portion as an example of a forged product. First, the cylindrical material W0 ((a) in FIG. 1) is pressed in the axial direction to form a disk-shaped preform W1 ((a) in FIG. 1), and then blocked by the preform W1. Forging is performed to form an intermediate molded product W2 ((c) in FIG. 1) in which the rough tooth shape 2 is formed on the outer periphery and the concave grooves 3 and 4 are formed on both end surfaces in the axial direction. Next, the partition wall 5 formed between the concave grooves 3 and 4 of the intermediate molded product W2 is punched to form a bevel gear (FIG. 1D) which is a finished product.

  First, a closed forging device 1 according to an embodiment of the present invention will be described with reference to FIG. Reference numeral 1 denotes a closed forging device for forming a bevel gear. The closed forging device 1 includes a movable die 11 and a fixed die 51 which are arranged opposite to each other on the same axis of the closed forging device 1. This closed forging device 1 is used in a horizontal multi-stage forging device.

  The movable die 11 includes a first die 12 having a forming tooth portion 16 for forming the rough tooth shape 2 of the intermediate formed product W2 on the inner periphery, and a punch holder 20 disposed on the side opposite to the fixed die of the first die 12. The first knockout 22 is arranged on the inner peripheral side of the first mold 12 and the punch holder 20.

  The movable mold 11 will be described in more detail. The first mold 12 has a substantially cylindrical shape, a first large-diameter portion 13, and a first small-diameter portion that is continuous from the first large-diameter portion 13 to the fixed mold side and has an outer diameter smaller than that of the first large-diameter portion 13. 14 and so on. The first small diameter portion 14 has a first opening 19 that opens to the fixed mold side, and two convex portions 15a and concave portions 15b each having a tapered surface 37 are alternately formed on the outer peripheral surface. A first step portion 18 is formed inside the first opening 19, and a forming tooth portion 16 is formed continuously from the first step portion 18. Convex end portions 17 for forming the concave grooves 3 of the intermediate molded product W1 are formed continuously from the molding tooth portion 16 to the inside. The punch holder 20 is fixed by a bolt 21 so as to be integrated with the first mold 12. Further, the first knockout 22 is disposed on the same axis as the first mold 12 and is held in a state of being movable in the axial direction.

  Next, the fixed mold 51 will be described. The fixed mold 51 includes a die block 66 disposed on the outermost periphery, an engagement mechanism 80 disposed on the inner side of the die block 66, and a second mold 52. The engagement mechanism 80 includes a substantially cylindrical case 81 and four divided pieces 82 that are arranged on the inner peripheral side of the case 81 and are divided in the radial direction. The second mold 52 has a substantially cylindrical shape, and the counter punch 60 is disposed inside. The case 81 and the second mold 52 are supported by a ring-shaped first plate 61, and the first plate 61 is urged by a second spring 72 that is a buffer mechanism. The second spring 72 is held by a second plate 62 and a third plate 63 that are disposed on the opposite side of the first plate 61 from the movable side. The counter punch 60 is held on the fourth plate 64 via the counter punch support plate 63, and the second knockout 73 is the same as the second mold 52 inside the counter punch 60, the counter support plate 63 and the fourth plate 64. It is arranged to be able to advance and retreat on the axis. The second plate 62 is fixed to the die block 66 with a headless screw 99.

  The fixed mold 51 will be described in more detail. First, the second mold 52 will be described. The second mold 52 includes a second large diameter portion 53 and a second small diameter portion 54 that is continuous from the second large diameter portion 53 to the movable mold side and has an outer diameter smaller than that of the second large diameter portion 53. The second large-diameter portion 53 has a plurality of cylindrical hole portions 56 in which the first springs 71 serving as a buffer mechanism are disposed on the non-movable type side. The second small diameter portion 54 includes a second concave portion 55b that is continuous from the second large diameter portion 53 and has a smaller outer diameter than the concave portion 15b of the first mold 12, and a second convex portion 55a that is continuous from the second concave portion 55b. One second step portion 68 formed continuously from the second convex portion 55 a to the movable mold side is formed so as to contact the first opening side end surface 23 of the first mold 12. The second recess 55 b has a shaft face 39 whose surface on the second protrusion 55 a side is perpendicular to the axis of the second mold 52. Here, a die engraving space is formed by the counter punch 60 disposed inside the second mold 52, the movable mold side opening 69 of the second mold 52, and the molding tooth portion 16 of the first mold 12.

  Next, the engagement mechanism 80 of the fixed mold 51 will be described. The inner peripheral surface 83 of the case 81 has a tapered shape having a smaller diameter toward the non-movable mold side. The movable mold side of the case 81 has an inner diameter smaller than the inner diameter of the movable mold side case opening 93 of the case 81. A disk-shaped retaining ring 92 having a disk shape is disposed, and the case 81 and the retaining ring 92 are integrated by a bolt (not shown). Further, as shown in FIG. 5A, the outer peripheral surface 85 of the divided piece 82 has a tapered shape that can move along the inner peripheral surface 83 of the case 81, and a retaining ring 92 is provided at the movable side end thereof. A ring step portion 87 is formed in contact with the ring. Further, three convex portions 86a, 86b, 86c are formed on the inner peripheral surface of the divided piece 82, and two concave portions 86d, 86e are formed between the convex portions. The two convex portions 86a, 86b on the movable mold side are fitted into the two concave portions 15b of the first mold 12, and the convex portion 86c on the fixed mold side protrudes inward from the other two convex portions 86a. The engagement convex portion which is a retaining portion is fitted into the concave portion 55 b of the second mold 52. When the two convex portions 86a and 86b on the movable mold side are arranged at the maximum diameter portion of the inner diameter of the case 81, the two convex portions 86a and 86b have a length in the axial direction that does not fit into the concave portion 15b of the first mold 12. The convex portion 86 c has a length in the axial direction in which a part thereof is fitted in the concave portion 55 b of the second mold 52. In addition, the convex portions 86a and 86b have a tapered surface 95 that is inclined so as to have a smaller diameter toward the axis of the second mold 52, and the engaging convex portion 86c has a movable mold side surface on the second mold. The horizontal plane 94 is perpendicular to the axis of 52. As shown in FIG. 5A, the divided piece 82 has a shape composed of a first guide portion 90 that is wider in front view and a second guide portion 91 that is narrower than the first guide portion 90. The outer peripheral surface of the guide part 90 is formed in a straight line when viewed from the front. As shown in FIG. 6, a split piece engaging portion 97 is formed in the case 81 so as to match the shape of the split piece 82, and the split piece 82 is disposed in the split piece engaging portion 97 of the case 81. The guide portion 90 of the divided piece 82 serves as a restricting portion that restricts the movement of the divided piece 82 in the radial direction and the circumferential direction within the divided piece engaging portion 97.

  Next, a method for forming the intermediate molded product W2 by performing closed forging with the closed forging device 1 will be described. This closed forging device 1 is used in a multistage horizontal press. First, as shown in FIG. 2, in the closed forging device 1, the movable mold 11 and the fixed mold 51 are opposed to each other on the same axis. In the movable mold 11, the first knockout 22 projects from the first mold 12 to the fixed mold side. Further, in the fixed mold 51, the retaining ring 92 is arranged in the same position as the movable mold side end portion of the die block 66, and the ring step portion 87 of the divided piece 82 abuts against the retaining ring 92, and the divided piece The outer peripheral surface 85 of the 82 is disposed at the maximum diameter portion of the case 81. The second mold 52 is arranged in a state in which a part of the engaging convex portion 86 c of the divided piece 82 is fitted in the concave portion 55 b of the second mold 52. A disk-shaped preform W1 is disposed between the movable mold 11 and the fixed mold 51 by a conveying means (not shown).

  The preform W1 conveyed by the conveying means (not shown) is pushed by the first knockout 22 and moves to a position where it abuts on the second knockout 73 inside the second mold 52, and the first knockout 22 and the second knockout 22 It is sandwiched between knockouts 73. Subsequently, the movable mold 11 moves to the fixed mold side, the first opening side end face 23 of the first mold 12, the second step portion 68 of the second mold 52, and the first step portion 18 of the first mold 12. The movable mold side end face 32 of the second mold 52, the fixed mold side end face 33 of the first large-diameter portion 13 of the first mold 12, and the movable mold side end face 34 of the divided piece 82 abut. At this time, the first uneven portion 15 of the first mold 12 and the piece uneven portion 86 of the divided piece 82 are not fitted.

  Next, the first mold 12 further moves to the fixed mold side. Then, as shown in FIG. 3, the second mold 52 is pushed by the first mold 12 and moves to the side opposite to the movable mold, and accordingly, the first spring 71 in the second mold 12 is compressed and the first mold 71 is compressed. The plate 61 is moved to the non-movable type side. Since the first plate 61 moves to the anti-movable type in this way, the case 81 held by the first plate 61 also moves to the non-movable type side. The divided piece 82 is also pushed by the first mold 12 and starts moving toward the non-movable mold side. However, the outer peripheral surface 85 of the divided piece 82 formed in a straight line when viewed from the front is the entire outer peripheral surface 85 of the case 81. Therefore, the received load moves without being partially biased. At this time, since the division piece 82 is restrained from moving in the radial direction and the circumferential direction by the restricting portion 90, the division piece 82 moves in the radial direction and the circumferential direction by an impact pushed by the first mold 12. It moves without being arranged at a predetermined position. At this time, the split piece 82 moves along the taper surface of the inner peripheral surface 83 of the case 81, so that the diameter gradually decreases, and the uneven portion 15 of the first mold 12 and the uneven portion 55 of the second mold 52. The piece concavo-convex portion 86 of the split piece 82 is gradually fitted, and the engagement convex portion 86c is further increased in a portion to be fitted with the concave portion 55b of the second mold 52. Here, the concave and convex portions 15a and 86b and 86c fitted to the concave and convex portion 15 of the first mold 12 and the first die 12 of the divided piece 82 are in contact with the tapered surfaces 37 and 95 formed in a tapered shape, respectively. Even if there is some dimensional error in each, the fitting is easily performed.

  Thereafter, as shown in FIG. 4, the preform W1 is pressed in the engraving space defined by the first mold 12, the second mold 52, and the counter punch 60, and formed into an intermediate molded product W2. At this time, the piece concavo-convex portion 86 of the split piece 82 is fitted to the concavo-convex portions 15 and 55 of the first mold 12 and the second mold 52, so that the first mold 12 and the second mold 52 are in the axial direction. The first mold 12 and the second mold 52 can be kept in contact with each other, and the intermediate molded product W2 is molded in a desired closed state.

  When the molding of the molded product to the intermediate molded product W2 is completed, the movable mold 11 starts to move to the anti-fixed mold side, and the second mold 12 and the divided piece 82 also move to the anti-fixed mold side. W2 also moves. Then, the case 81 also starts moving to the anti-fixed mold side by the urging force of the second spring 72. Further, since the split piece 82 moves along the inner peripheral surface 83 of the case 81, the diameter gradually increases, and the concave and convex portions 86a and 86a of the split piece 82 extend from the concave and convex portions 15 and 55 of the first mold 12 and the second mold 52. 86b, 86d and 86e are gradually disengaged. Here, since the convex portions 86a and 86b of the split piece 82 have a tapered surface 95 that is inclined toward the axis of the second mold 52, the convex portions 86a and 86b are easily disengaged from the concave portion 15b of the first mold 12. The mating convex portion 86 c is in a state in which it is difficult to come off from the concave portion 55 b of the second mold 52 because the horizontal surface 94 in contact with the concave portion 55 b of the second mold 52 is perpendicular to the axis of the second mold 52. At this time, since the second mold 52 moves to the movable mold side with the urging force of the first spring 71 applied, the movement does not stop midway and the movement speed does not slow down, and the movement is stabilized. . Thereafter, the split piece 82 stops when the ring step portion 87 abuts against the retaining ring 92. At this time, the piece uneven portions 86a, 86b, 86d, and 86e are completely separated from the uneven portion 15 of the first mold 12, and the movable die 11 moves further to the anti-fixed die side. Since the retaining portion 86 c is partially engaged with the second recess 55 b of the second mold 52, the second mold 52 stops moving as the split piece 82 stops. Next, when the movable mold 11 is completely separated from the fixed mold 51 and reaches a predetermined position, the intermediate molded product W2 is taken out by a conveying means (not shown) and conveyed to the next step.

  In this embodiment, three convex parts of the split piece are formed, and the convex part on the most fixed mold side is formed as a retaining part, but the number of convex parts is not limited to this number. Absent. Further, the number of divided pieces is not limited to four, and can be designed to an arbitrary number.

  In the present embodiment, the closed forging device is used as a horizontal multi-stage forging device, but it goes without saying that it can also be used as a single device.

It is a cross-sectional top view showing the process of the forge molding of the product by which an intermediate molded product is shape | molded with the obstruction | occlusion forging apparatus by the Example of this invention. It is a partial section top view showing the state before shaping | molding of the product by the closed forging apparatus by the Example of this invention. It is a partial cross section top view showing the state in the middle of the shaping | molding of the product by the closed forging apparatus in the Example of this invention. It is a fragmentary sectional top view showing the state of the end of fabrication of a product by the closure forging device by the example of the present invention. It is the division piece by the Example of this invention, (A) is a top view, (A) is a front view. It is a front view of the case and division | segmentation piece by the Example of this invention.

Explanation of symbols

11 movable mold 12 first mold 13 first large diameter part 14 first small diameter part 15 uneven part 51 fixed mold 52 second mold 53 second large diameter part 54 second small diameter part 55 uneven part 80 engaging mechanism 81 case 82 Split piece 83 (Case) Inner peripheral surface 85 (Split piece) Outer peripheral surface 86 Piece uneven part 86a Other convex part 86c Retaining part

Claims (5)

A movable mold (11) having a first mold (12) and movable in the axial direction and a fixed mold (51) having a second mold (52) are arranged opposite to each other on the same axis, In the closed forging device in which a die-sculpting space is formed by the first die (12) and the second die (52),
The first mold (12) has an uneven first uneven portion (15) formed on the outer peripheral surface on the fixed mold side,
The second mold (52) is composed of a second small diameter part (54) in which an uneven second uneven part (55) is formed on the outer peripheral surface on the movable mold side,
An engagement mechanism (80) including a plurality of divided pieces (82) and a case (81) for holding the divided pieces (82) on the inner peripheral side is disposed on the outer peripheral side of the second mold (52). And
The case (81) has a tapered shape in which the inner peripheral surface (83) has a smaller diameter from the movable mold side to the fixed mold side,
The divided piece (82) has a tapered shape in which the outer peripheral surface (85) has a smaller diameter from the movable mold side to the fixed mold side, and the first mold (12) and the second mold ( 52), a plurality of piece concavo-convex portions (86) to be fitted to the concavo-convex portions (15, 55) are formed, and the piece concavo-convex portions (86) are fitted to the concave portions (55b) of the second mold (52). The at least one convex portion (86c) is a retaining portion projecting inward from the other convex portion (86a),
The second mold (52) and the divided piece (82) are disposed so as not to be separated by the retaining portion (86c),
The split piece (82) moves along the inner peripheral surface (83) of the case (81), and the concave and convex portions (15, 55) of the first mold (12) and the second mold (52). The closed forging device, wherein the piece uneven portion (86) of the divided piece (82) is fitted to the closed forging device.   The closed forging device according to claim 1, wherein the split piece (82) is formed with a restricting portion (90) for restricting movement of the split piece (82) only in the axial direction.   The said division | segmentation piece (82) has the outer peripheral surface (85) contact | abutted with the internal peripheral surface (83) of the said case (81), and is formed in a straight line by the front view. Closed forging device.   4. The closed forging device according to claim 1, wherein the second mold (52) and the case (81) are supported by buffer mechanisms (71, 72) so as to be movable in the axial direction. 5. .   The retaining part (86c) of the split piece (82) has a horizontal surface (94) whose surface abutting against the recess (55) of the second mold is perpendicular to the axis of the closed forging device, The convex portions (86a, 86b) other than the retaining portion (86c) have a tapered surface (95) inclined toward the axial center of the closed forging device (1). Closed forging equipment.

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