JP2018069320A - Molding device and molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding device and a molding method capable of restraining breaking of a die and a punch.SOLUTION: A molding device 1 of the present embodiment is the molding device 1 for molding a shaft-like forging part 70 from a round-bar raw material 60, and comprises a punch 10 having a recessed part 11, a rod-like upward thrust-in punch 20 fitted to a through-hole 19 of the punch 10, a die 30 having a recessed part 31, a recessed part 32 opened on a bottom surface 31d of the recessed part 31 and a through-hole 39 of penetrating up to an undersurface from a bottom surface 32d of the recessed part 32, a cylindrical sleeve 40 for forming a through-hole 49 by fitting to the through-hole 39 and a rod-like downward thrust-in punch 50 fitted to the through-hole 49, and the punch 10 descends, and axial- restriction-molds by extruding a lower part of the round-bar raw material 60 to the through-hole 39, and the sleeve 40 rises, and upwardly moves the round-bar raw material 60 molded by axial restriction, and the downward thrust-in punch 50 rises, and molds a lower deep hole 76 on a lower end surface 60b of the round-bar raw material 60.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a molding apparatus and a molding method, and, for example, relates to a molding apparatus and a molding method for forging a shaft forged part formed by deep hole molding.

  Patent Document 1 describes a molding method in which deep hole molding is performed on a round bar material or an intermediate molded body. In the forming method of Patent Document 1, after inserting a round bar material into the opening of a die having a reduced diameter portion, the upper end surface of the round bar material is pushed out to the reduced diameter portion by an outer punch, and is applied to the upper end surface of the round bar material. Deep hole molding is performed with an inner punch for drilling.

JP 2003-266139 A

  As in the forming method described in Patent Document 1, when a round bar material is sealed and deep hole forming is performed, an excessive load is applied to the punch for punching, and breakage frequently occurs.

  The present invention has been made to solve such a problem, and provides a molding apparatus and a molding method capable of suppressing breakage of a die, a punch, and the like.

  A molding apparatus according to an aspect of the present invention is a molding apparatus for molding a shaft forged part from a round bar material, and has a punch recess that opens downward when the axial direction of the shaft forged part is an up-down direction. A punch, a rod-like upper protrusion punch fitted into an upper protrusion punch through hole penetrating from the upper surface of the punch to the bottom surface of the punch recess, a die first recess opening upward, and a bottom surface of the die first recess A die having a die second recess opening in the die, a sleeve through hole penetrating from a bottom surface to a lower surface of the die second recess and having an opening narrower than a lower end surface of the round bar material, and the sleeve through hole. A cylindrical sleeve formed with a through-hole for a lower indentation punch that is inserted in the axial direction and a rod-like lower indentation punch that is fitted in the through-hole for the lower indentation punch. The lower part of the round bar material arranged between the punch and the die is extruded into the through hole for the sleeve, and the shaft is drawn, and the sleeve is raised and the shaft is drawn. Further, the round bar material is moved upward to a predetermined position together with the punch, and the lower thrust punch is lifted to form a lower deep hole on the lower end surface of the round bar material moved to the predetermined position. The punch is lowered and presses the round bar material in which the lower deep hole is molded, and the round bar material is upset in the first die recess and the second die recess, The upper punch is lowered to form the upper deep hole on the upper end surface of the round bar material on which the lower deep hole is formed. With such a configuration, breakage of a die, a punch, or the like can be suppressed.

  A molding method according to an aspect of the present invention is a molding method for molding a shaft forged part from a round bar material, and has a punch recess that opens downward when the axial direction of the shaft forged part is the vertical direction. A punch, a rod-like upper protrusion punch fitted into an upper protrusion punch through hole penetrating from the upper surface of the punch to the bottom surface of the punch recess, a die first recess opening upward, and a bottom surface of the die first recess A die having a die second recess opening in the die, a sleeve through hole penetrating from a bottom surface to a lower surface of the die second recess and having an opening narrower than a lower end surface of the round bar material, and the sleeve through hole. A cylindrical sleeve formed with a through-hole for a lower indentation punch that is inserted in the axial direction and a rod-like lower indentation punch that is fitted in the through hole for the lower indentation punch. The lower part of the round bar material disposed between the punch and the die is pushed down into the through-hole for sleeve to form a shaft drawing, and the shaft is drawn up by raising the sleeve. The step of moving the formed round bar material together with the punch up to a predetermined position, and raising the lower protrusion punch to lower the lower end surface of the round bar material moved to the predetermined position. Forming the hole, and lowering the punch to press the round bar material in which the lower deep hole is formed, so that the round bar material is placed in the first die recess and the second die recess. A step of forming an upper deep hole on an upper end surface of the round bar material formed with the lower deep hole by lowering the upper punch. And, equipped with a. With such a configuration, breakage of a die, a punch, or the like can be suppressed.

  According to the present invention, there are provided a molding apparatus and a molding method capable of suppressing breakage of a die, a punch and the like.

It is sectional drawing which illustrated the structure of the shaping | molding apparatus which concerns on embodiment. It is sectional drawing which illustrated the shaft forging part shape | molded with the shaping | molding apparatus which concerns on embodiment. It is the flowchart figure which illustrated the shaping | molding method of the shaft forge parts using the shaping | molding apparatus which concerns on embodiment. (A)-(d) is process sectional drawing which illustrated the shaping | molding method of the shaft forging components using the shaping | molding apparatus which concerns on embodiment. (A)-(d) is process sectional drawing which illustrated the shaping | molding method of the shaft forging components using the shaping | molding apparatus which concerns on embodiment.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

  A molding apparatus according to an embodiment will be described. First, the structure of the shaping | molding apparatus which concerns on embodiment is demonstrated. FIG. 1 is a cross-sectional view illustrating the configuration of a molding apparatus according to an embodiment. As shown in FIG. 1, the molding apparatus 1 includes a punch 10, an upper punch 20, a die 30, a sleeve 40, and a lower punch 50. In FIG. 1, a round bar material 60 is also shown.

  The forming apparatus 1 forms a shaft forged part from a round bar material 60, for example, a round bar-like solid round bar material 60 extending in the axial direction. The round bar member 60 includes, for example, metal as a material. The axial direction of the round bar material 60 placed on the molding apparatus 1 is matched with the axial direction L of the molding apparatus 1 that molds the shaft object forged part and the shaft object forged part. In order to describe the molding apparatus 1, the axial direction L is defined as the vertical direction. In addition, the up-down direction is introduced for explaining the molding apparatus 1, and the axial direction L is not limited to the up-down direction when the molding apparatus 1 is used.

  FIG. 2 is a cross-sectional view illustrating a shaft forged part 70 formed by the forming apparatus 1 according to the embodiment. As illustrated in FIG. 2, the shaft forged component 70 has a central axis, and may be, for example, a member that is rotationally symmetric with respect to the central axis, or may have a portion that is not partially rotationally symmetric. When the central axis is the axial direction L, the shaft forged component 70 includes an upper cylindrical portion 71, a flange portion 72, a lower cylindrical portion 73, and a small diameter cylindrical portion 74 in order from the top.

  The upper cylindrical portion 71 is, for example, a cylindrical member. The flange portion 72 is a flange-shaped member that extends outward from the central axis more than the upper cylindrical portion 71 and the lower cylindrical portion 73. The outer diameter of the flange portion 72 is larger than the outer diameters of the upper cylindrical portion 71 and the lower cylindrical portion 73. The lower cylindrical portion 73 is, for example, a cylindrical member. The small diameter cylindrical portion 74 is a cylindrical member and has an outer diameter smaller than the outer diameter of the lower cylindrical portion 73. An upper deep hole 75 is formed on the upper surface 71 a of the upper cylindrical portion 71. A lower deep hole 76 is formed in the lower surface 74 b of the small diameter cylindrical portion 74. The central axes of the upper deep hole 75 and the lower deep hole 76 are also in the axial direction L.

  Returning to FIG. 1, each member of the molding apparatus 1 will be described. The punch 10 is disposed above the round bar material 60. The punch 10 has a recess 11 (punch recess 11) that opens downward. The punch 10 has, for example, a cylindrical shape having an upper surface 10a and a lower surface 10b, and a recess 11 is formed on the lower surface 10b. The punch 10 does not stick to the cylindrical outer shape as long as the concave portion 11 opened downward is formed. The central axis of the recess 11 coincides with the axial direction L. The recess 11 is, for example, circular when viewed from below, and the inner peripheral surface 11c of the recess 11 is cylindrical. The recess 11 is not limited to a circular shape when viewed from below, and the inner peripheral surface 11c of the recess 11 is not limited to a cylindrical shape. The recesses other than the recesses 11 shown below are not limited to a cylindrical shape.

  The opening of the recess 11 is narrower than the upper end surface 60 a of the round bar material 60. That is, the upper end surface 60 a of the round bar material 60 is wide so as to cover the opening of the recess 11. For example, the inner diameter of the recess 11 is smaller than the outer diameter of the round bar material 60. It is desirable that the angle formed by the inner peripheral surface 11c of the recess 11 and the lower surface 10b is tapered. This facilitates the axial drawing of the upper portion of the round bar material 60 with the recess 11.

  A through hole 19 (upper punch punch through hole) is formed in the punch 10. The through hole 19 penetrates from the upper surface 10 a of the punch 10 to the bottom surface 11 d of the recess 11. The through hole 19 has, for example, a circular shape when viewed from above. The through hole 19 is not limited to a circular shape when viewed from above. The through holes other than the through hole 19 shown below are not limited to a circular shape. The central axis of the through hole 19 coincides with the axial direction L, for example.

  The relationship between the punch 10 and the shaft forged part 70 will be described. The upper cylindrical portion 71 of the shaft forged part 70 is formed in the recess 11 of the punch 10. Therefore, the shapes of the inner peripheral surface 11 c and the bottom surface 11 d of the recess 11 in the punch 10 substantially match the shapes of the outer peripheral surface 71 c and the upper surface 71 a of the upper cylindrical portion 71 in the shaft forged part 70. The inner diameter of the recess 11 is substantially the same as the outer diameter of the upper cylindrical portion 71.

  The upper punch 20 is disposed above the round bar material 60. The upper punch 20 is a rod-shaped member. The center axis of the upper punch 20 coincides with the axial direction L. The upper punch 20 has a shape fitted into the through hole 19 of the punch 10. Therefore, the lower portion 21 of the upper protrusion punch 20 can be inserted into the through hole 19 in the upper surface 10a of the punch 10 from above the punch 10 and protrude into the recess 11 from the through hole 19 in the bottom surface 11d.

  The relationship between the upper piercing punch 20 and the shaft forged part 70 will be described. The upper deep hole 75 of the shaft wrought part 70 is formed by pushing the upper piercing punch 20. Therefore, the shape of the outer peripheral surface 21 c of the lower portion 21 of the upper punching punch 20 substantially matches the shape of the inner peripheral surface 75 c of the upper deep hole 75 formed in the upper surface 71 a of the upper cylindrical portion 71. The outer diameter of the lower portion 21 of the upper punch 20 is substantially the same as the inner diameter of the upper deep hole 75.

  The die 30 is disposed below the round bar material 60. The die 30 includes a concave portion 31 (die first concave portion) opened upward, a concave portion 32 (die second concave portion) opened on the bottom surface 31 d of the concave portion 31, and a through hole 39 penetrating from the bottom surface 32 d of the concave portion 32 to the lower surface 30 b. (Sleeve through-hole). The through hole 39 in the bottom surface 32 d of the recess 32 has an opening narrower than the lower end surface 60 b of the round bar material 60. That is, the lower end surface 60 b of the round bar material 60 is wide so as to cover the opening of the through hole 39. For example, the inner diameter of the through hole 39 is smaller than the outer diameter of the round bar material 60.

  The die 30 has an inner peripheral surface 31 c of the recess 31, an inner peripheral surface 32 c of the recess 32, and an inner peripheral surface 39 c of the through hole 39. The inner peripheral surface 31c, the inner peripheral surface 32c, and the inner peripheral surface 39c are sequentially coupled downward. There is a step between the inner peripheral surface 31c and the inner peripheral surface 32c. The step is the bottom surface 31 d of the recess 31. There is a step between the inner peripheral surface 32c and the inner peripheral surface 39c. The step is the bottom surface 32 d of the recess 32.

  Thus, the inner peripheral surface of the die 30 has a two-step staircase shape. The axial direction of each inner peripheral surface substantially coincides with the axial direction L. For example, the inner diameter of the recess 31 is larger than the inner diameter of the recess 32. The inner diameter of the recess 32 is larger than the inner diameter of the through hole 39.

  Explaining the relationship between the die 30 and the shaft forged part 70, the flange portion 72, the lower cylindrical portion 73 and the small diameter cylindrical portion 74 of the shaft forged component 70 are formed in the concave portion 31, the concave portion 32 and the through hole 39 of the die 30. Is done. Therefore, the shape of the inner peripheral surface 31 c of the concave portion 31 in the die 30 substantially matches the shape of the outer peripheral surface 72 c of the flange portion 72 in the shaft forged part 70. Therefore, for example, the inner diameter of the recess 31 substantially matches the outer diameter of the flange portion 72.

  The shape of the inner peripheral surface 32 c of the concave portion 32 in the die 30 substantially matches the shape of the outer peripheral surface 73 c of the lower cylindrical portion 73 in the shaft forged part 70. Therefore, for example, the inner diameter of the recess 32 substantially matches the outer diameter of the lower cylindrical portion 73.

  The shape of the inner peripheral surface 39 c of the through hole 39 in the die 30 substantially matches the shape of the outer peripheral surface 74 c of the small diameter cylindrical portion 74 in the shaft forged part 70. Therefore, for example, the inner diameter of the through hole 39 substantially matches the outer diameter of the small diameter cylindrical portion 74.

  The sleeve 40 is disposed below the round bar material 60. The sleeve 40 is fitted into the through hole 39 of the die 30. The sleeve 40 is formed with a through hole 49 (a bottom punch punch through hole) penetrating in the axial direction from the upper end surface 40a to the lower end surface 40b. The axial direction of the sleeve 40 and the through hole 49 coincides with the axial direction L. Thus, for example, the sleeve 40 is a cylindrical member, for example, a cylindrical member. In that case, the outer diameter of the sleeve 40 substantially matches the inner diameter of the through hole 39 of the die 30. The upper portion 41 of the sleeve 40 can be inserted into the through hole 39 in the lower surface 30 b of the die 30 from below the die 30.

  The relationship between the sleeve 40 and the shaft forged part 70 will be described. The shape of the upper end surface 40a of the sleeve 40 substantially matches the shape of the lower surface 74b of the shaft forged part 70.

  The lower punch 50 is disposed below the round bar material 60. The lower protrusion punch 50 is a rod-shaped member. The lower protrusion punch 50 has a shape fitted in the through hole 49 of the sleeve 40. Accordingly, the upper portion 51 of the lower protrusion punch 50 is inserted into the through hole 49 in the lower end surface 40b of the sleeve 40 from below the sleeve 40, and into the through hole 39 of the die 30 from the through hole 49 in the upper end surface 40a of the sleeve 40. Can be protruded. The central axis of the lower protrusion punch 50 coincides with the axial direction L.

  The relationship between the lower protrusion punch 50 and the shaft forged part 70 will be described. The lower deep hole 76 of the shaft forged part 70 is formed by pressing the lower protrusion punch 50. Therefore, the shape of the outer peripheral surface 51c of the upper portion 51 of the lower protrusion punch 50 substantially matches the shape of the inner peripheral surface 76c of the lower deep hole 76 formed in the lower surface 74b of the small diameter cylindrical portion. The outer diameter of the upper portion 51 of the lower punch 50 is substantially the same as the inner diameter of the lower deep hole 76.

  Next, a method for forming the shaft forged part 70 will be described as an operation of the forming apparatus 1 according to the embodiment. FIG. 3 is a flowchart illustrating a method for forming a shaft forged part using the forming apparatus according to the embodiment. 4A to 4D and FIGS. 5A to 5D are process cross-sectional views illustrating a method for forming a shaft forged part using the forming apparatus according to the embodiment.

  First, as shown in step S <b> 1 of FIG. 3 and FIG. 4A, the round bar material 60 is disposed at a predetermined position of the molding apparatus 1. Specifically, the axial direction of the round bar blank 60 is aligned with the axial direction L of the molding device 1 for molding the shaft forging component 70 and the shaft forging component 70, and is arranged between the punch 10 and the die 30. And the lower part of the round bar raw material 60 is inserted in the recessed part 32 of the die | dye 30, for example. The lower end surface 60 b of the round bar material 60 is wide so as to cover the opening of the through hole 39. For example, the round bar material 60 has an outer diameter larger than the inner diameter of the through hole 39. For example, the round bar material 60 has an outer diameter that is substantially the same as the inner diameter of the recess 32 in the die 30. Therefore, the lower part of the round bar material 60 is disposed so as to be fitted into the recess 32.

  The upper ends of the sleeve 40 and the lower protrusion punch 50 are arranged in the vicinity of the lower end of the through hole 39. Further, the punch 10 is disposed above the round bar blank 60 with the concave portion 11 of the punch 10 facing downward. The lower end of the upper protrusion punch 20 is disposed on the bottom surface 11 d of the recess 11.

  Next, as shown in step S2 of FIG. 3 and FIG. 4B, shaft drawing of the round bar material 60 is performed. Specifically, for example, by lowering the punch 10, the upper portion of the round bar material 60 is axially drawn by the recess 11 of the punch 10 having an opening narrower than the upper end surface 60 a of the round bar material 60. The upper end surface 60 a of the round bar material 60 is wide so as to cover the opening of the recess 11 of the punch 10. For example, the outer diameter of the round bar material 60 is larger than the inner diameter of the recess 11 of the punch 10. Therefore, the punch 10 is lowered and the upper part of the round bar material 60 is axially drawn by the recess 11 of the punch 10. The portion of the round bar material 60 that has been subjected to axial drawing is referred to as an axial drawing portion 68. The outer diameter of the shaft restricting portion 68 is substantially the same as the inner diameter of the recess 11.

  Further, by lowering the punch 10 together with the round bar material 60 pushed into the recess 11, the lower part of the round bar material 60 is extruded into the through-hole 39 of the die 30 to be axially drawn. The through hole 39 has an opening narrower than the lower end surface 60 b of the round bar material 60. For example, the through hole 39 has an inner diameter that is smaller than the outer diameter of the round bar material 60. Therefore, the lower part of the round bar material 60 extruded into the through hole 39 is formed by axial drawing. In this way, the punch 10 descends, and the lower part of the round bar material 60 is extruded into the through hole 39 to be axially drawn. A portion of the lower portion of the round bar material 60 that has been subjected to shaft drawing is referred to as a shaft drawing portion 69. The outer diameter of the shaft restricting portion 69 is substantially the same as the inner diameter of the through hole 39.

  When the shaft drawing is performed, the length in the axial direction L of the shaft drawing portion 69 in the round bar material 60 is made longer than the length of the portion corresponding to the shaft drawing portion 69 in the shaft forged part 70. Specifically, the lower portion of the round bar material 60 is axially drawn so as to be longer than the axial length of the small diameter cylindrical portion 74 of the shaft forged part 70.

  Here, the length in the axial direction is simply referred to as the length. In particular, unless otherwise stated, the length means a length in the axial direction.

  In advance, a mark M is attached to a location located below the bottom surface 32 d of the concave portion 32 of the die 30 by the length of the small diameter cylindrical portion 74. When the shaft drawing is performed, the shaft drawing is performed until the lower end surface 60b of the round bar material 60 is positioned below the mark M. Thereby, the length of the shaft restricting portion 69 in the round bar material 60 can be made longer than the length of the small diameter cylindrical portion 74 of the shaft forged part 70.

  Next, as shown in step S3 in FIG. 3 and FIG. 4C, the sleeve 40 is lifted to move the shaft bar-formed round bar material 60 upward to a predetermined position. Specifically, the upper end surface 40 a of the sleeve 40 is brought into contact with the lower end surface 60 b of the round bar material 60. Then, by raising the sleeve 40, the round bar material 60 is pushed up to a predetermined position. The predetermined position is, for example, a position where the length of the shaft throttle portion 69 that contacts the inner peripheral surface 39c of the through hole 39 is substantially the same as the length of the small diameter cylindrical portion 74 of the shaft forged part 70.

  For example, a mark M is attached in advance to a position located below the bottom surface 32 d of the concave portion 32 of the die 30 by the length of the small diameter cylindrical portion 74. Therefore, when the round bar material 60 is moved upward by the sleeve 40, the lower end surface 60b of the round bar material 60 is moved to the position where the mark M is marked. In this way, the sleeve 40 moves up and moves the round bar material 60 upward to a predetermined position.

  When the shaft bar 60 is moved upward to a predetermined position, the lower portion of the shaft bar 69 of the round bar material 60 is in contact with the inner peripheral surface 39 c of the through hole 39 of the die 30. On the other hand, the inner diameter of the recess 32 is larger than the outer diameter of the shaft restricting portion 69 of the round bar material 60. Therefore, there is a gap between the upper portion of the shaft restricting portion 69 of the round bar material 60 and the inner peripheral surface 32 c of the concave portion 32 of the die 30.

  When the round bar material 60 is moved upward, the round bar material 60 is moved upward to a predetermined position together with the punch 10 fitted to the upper part of the round bar material 60.

  Next, as shown in step S <b> 4 of FIG. 3 and FIG. 4D, a lower deep hole 76 is formed in the lower end surface 60 b of the round bar material 60. Specifically, the lower punch 50 is raised in a state where the gap between the shaft restricting portion 69 and the through hole 39 in the round bar material 60 is eliminated. Then, the upper portion 51 of the lower punch 50 is pushed into the lower end surface 60b of the round bar material 60 that has moved to a predetermined position. Accordingly, the lower punch 50 forms the lower deep hole 76 in the lower end surface 60 b of the round bar material 60.

  As shown in step S5 of FIG. 3 and FIG. 5A, when forming the lower deep hole 76, a round bar is formed in the gap between the round bar material 60 and the inner peripheral surfaces of the concave portion 31 and the concave portion 32. The material 60 is caused to flow. Thereby, the molding load for forming the lower deep hole 76 by the lower protrusion punch 50 can be dispersed at a portion close to the lower protrusion punch 50. That is, the molding load for molding the lower deep hole 76 can be reduced by a diversion method in which the round bar material 60 is caused to flow radially outward from the central axis. Therefore, the lower deep hole 76 can be formed with high accuracy while suppressing breakage of the upper punch 50 and the like.

  Further, since the shaft restricting portion 69 for forming the lower deep hole 76 is in contact with the through hole 39 of the die 30 and has no gap, the lower deep hole is defined based on the outer diameter of the round bar material 60. The center axis of the molding 76 can be made to coincide with the axial direction L with high accuracy.

  Next, as shown in FIG. 5B, the formation of the lower deep hole 76 is completed. In general, when a round bar material 60 that extends long in the axial direction, such as the shaft forged part 70, is formed, a buckling phenomenon may occur. However, in the present embodiment, the upper and lower portions of the round bar material 60 are formed by shaft drawing, and the round bar material 60 is fixed by the shaft drawing portion 68 and the shaft drawing portion 69. Thereby, generation | occurrence | production of a buckling phenomenon can be suppressed. At this time, the sleeve 40 may be raised by a length that lowers the upper punch 50 described later. Thereby, the length of the lower deep hole 76 can be maintained.

  Next, as shown in step S6 of FIG. 3 and FIG. 5C, upsetting and forming of the upper deep hole 75 are performed. Specifically, by lowering the punch 10, the round bar material 60 formed with the lower deep hole 76 is pressed. Then, upsetting of the round bar material 60 is performed in the recess 31 and the recess 32. That is, the inside of the recessed part 31 and the recessed part 32 are filled by making the round bar raw material 60 flow. In this way, the punch 10 descends to simultaneously form stepped shapes in the recess 31 and the recess 32 of the die 30.

  Further, the upper punch 20 is lowered in a state where the gap between the shaft restricting portion 68 in the round bar blank 60 and the inner peripheral surface 11c of the concave portion 11 of the punch 10 is eliminated. As a result, the upper punch 20 is pushed into the upper end surface 60 a of the round bar member 60. Thus, the upper punch 20 moves down to form the upper deep hole 75 in the upper end surface 60 a of the round bar material 60.

  The shaft restricting portion 68 is in a state where there is no gap due to the inner peripheral surface 11 c of the concave portion 11 of the punch 10, so that the center axis of the upper deep hole 75 is formed on the basis of the outer diameter of the round bar material 60. It can be made to coincide with the axial direction L with high accuracy.

  In this embodiment, the punch 10 and the upper punch 20 are lowered with a speed difference. For example, when the upper piercing punch 20 descends and the upper deep hole 75 is formed in the upper end surface 60a of the round bar blank 60, the lowering speed of the upper piercing punch 20 is the punch when the round bar blank 60 is upset. It is faster than the descent speed of 10. That is, the upsetting and the forming of the upper deep hole 75 are performed by lowering the upper thrusting punch 20 at a lowering speed faster than the punch 10 while lowering the punch 10. In this way, by lowering the upper protrusion punch 20 faster than the punch 10, upsetting of the punch 10 and formation of the upper deep hole 75 by the upper protrusion punch 20 are enabled. If the speed is the same, it is difficult to form the upper deep hole 75.

  The lower punch 50 does not fix the lower deep hole 76 after molding. The lower protrusion punch 50 is lowered when the punch 10 and the upper protrusion punch 20 are lowered. Thereby, the load of upsetting by the punch 10 and the upper piercing punch 20 can be dispersed downward to reduce the pressure. Further, when the lower protrusion punch 50 is lowered, the load applied to the lower protrusion punch 50 and the die 30 can be reduced. Note that the sleeve 40 may be lowered together with the lower protrusion punch 50. In this manner, as shown in FIG. 3D, the shaft forged part 70 can be forged.

Next, the effect of this embodiment will be described.
In the molding apparatus 1 of the present embodiment, when the round bar material 60 is subjected to axial drawing, the length of the axial drawing portion 69 in the axial direction L is set to a small diameter cylindrical portion 74 corresponding to the axial drawing portion 69 in the shaft forged part 70. After that, the round bar material 60 is moved upward by the sleeve 40. Thereby, a gap can be provided between the upper portion of the shaft restricting portion 69 and the die 30. Therefore, when the lower deep hole 76 is formed by the lower protrusion punch 50, the extruded round bar material 60 can be flowed into the gap. Accordingly, the load applied to the lower punch 50 and the die 30 can be dispersed to reduce the pressure. Therefore, the lifetime of dies, punches, etc. can be improved and the cost required for forging can be reduced.

  The upper deep hole 75 and the lower deep hole 76 are formed without gaps between the concave portion 11 of the punch 10 and the shaft restricting portion 68 and between the through hole 39 and the lower portion of the shaft restricting portion 69 in the die 30. Yes. As a result, the central axes of the molding of the upper deep hole 75 and the lower deep hole 76 can be made to coincide with the axial direction L with high accuracy on the basis of the outer diameter of the round bar material 60.

  Further, after the lower deep hole 76 is formed, the lower protrusion punch 50 is not fixed, and the lower protrusion punch 50 is lowered when the punch 10 and the upper protrusion punch 20 are lowered. Thereby, the load on the punch 10, the upper protrusion punch 20 and the lower protrusion punch 50 can be reduced. Therefore, the lifetime of dies, punches, etc. can be improved and the cost required for forging can be reduced.

  In the molding apparatus 1 of the present embodiment, the punch 10, the upper punch 20, the die 30, the sleeve 40, and the lower punch 50 press the round bar material 60. Using such an interlocking press, hollow parts such as the upper deep hole 75 and the lower deep hole 76 can be formed on the shaft forged part 70 with one press and one die. Therefore, the cost and time for forming the shaft forged part 70 can be reduced.

  When a round bar material 60 extending in the axial direction such as the shaft forged part 70 is formed, a buckling phenomenon may occur. However, in the present embodiment, the upper and lower portions of the round bar material 60 are formed by axial drawing, the axial drawn portions 68 and 69 are fixed without gaps, and the occurrence of buckling can be suppressed by interlocking press forming. it can. Further, when the upper deep hole 75 and the lower deep hole 76 are formed, a buckling phenomenon may occur. Similarly, in this case, by fixing the shaft restricting portions 68 and 69 without gaps, Generation | occurrence | production of a buckling phenomenon can be suppressed.

  If pipe-like material is used instead of forming hollow parts such as deep holes in the round bar material 60, not only the cost of the material, but also the manufacturing cost of forging press, intermediate annealing equipment, lubrication equipment, etc. required for forging Will also increase. Also, a wide manufacturing space is required. Furthermore, when a pipe material is used, manufacturing processes such as an intermediate annealing process and a re-lubrication process become longer and manufacturing time is required.

  On the other hand, in this embodiment, it can implement by the one press one die using the round bar raw material 60, and can suppress manufacturing cost, a manufacturing space, and manufacturing time. Further, the buckling phenomenon can be suppressed and the quality of the shaft forged part 70 can be improved.

  The embodiment according to the present invention has been described above. However, the present invention is not limited to the above-described configuration, and modifications can be made without departing from the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Molding apparatus 10 Punch 10a Upper surface 10b Lower surface 11 Recessed part (punch recessed part)
11c Inner peripheral surface 11d Bottom surface 19 Through hole (through hole for upper punch)
20 Upper punch 21 Lower 30 Die 30a Upper surface 30b Lower surface 31 Recess (Die first recess)
31c Inner peripheral surface 31d Bottom surface 32 Recess (Die second recess)
32c Inner peripheral surface 32d Bottom surface 39 Through hole (through hole for sleeve)
39c Inner peripheral surface 40 Sleeve 40a Upper end surface 40b Lower end surface 41 Upper part 49 Through hole (through hole for lower thrust punch)
50 Lower piercing punch 51 Upper 51c Outer peripheral surface 60 Round bar material 60a Upper end surface 60b Lower end surface 68, 69 Shaft restricting portion 70 Shaft forging part 71 Upper cylindrical portion 71a Upper surface 71c Outer peripheral surface 72 Flange portion 72c Outer peripheral surface 73 Lower cylindrical portion 73c Surface 74 Small-diameter cylindrical portion 74b Lower surface 74c Outer peripheral surface 75 Upper deep hole 76 Lower deep hole 75c, 76c Inner peripheral surface

Claims (10)

A molding device for molding a shaft forged part from a round bar material,
A punch having a punch recess opened downward when the axial direction of the shaft object forged part is the vertical direction;
A rod-shaped upper protrusion punch fitted into an upper protrusion punch through hole penetrating from the upper surface of the punch to the bottom surface of the punch recess;
A die first recess opened upward, a die second recess opened in the bottom surface of the die first recess, and an opening penetrating from the bottom surface to the bottom surface of the die second recess and narrower than the lower end surface of the round bar material. A die having a through hole for a sleeve,
A cylindrical sleeve fitted with the through-hole for sleeve and having a through-hole for lower protrusion punching through in the axial direction;
A rod-shaped lower protrusion punch fitted in the through hole for the lower protrusion punch, and
With
The punch is lowered, the lower part of the round bar material disposed between the punch and the die is extruded into the through hole for the sleeve, and the shaft is drawn.
The sleeve ascends and moves the round bar material formed by axial drawing to a predetermined position together with the punch,
The lower protrusion punch rises and forms a lower deep hole in the lower end surface of the round bar material moved to the predetermined position,
The punch descends, presses the round bar material formed with the lower deep hole, and performs upsetting of the round bar material into the first die recess and the second die recess,
The upper thrust punch is lowered to form the upper deep hole on the upper end surface of the round bar material formed with the lower deep hole.
Molding equipment. The upsetting and the forming of the upper deep hole are performed by lowering the upper piercing punch at a lowering speed faster than the punch while lowering the punch.
The molding apparatus according to claim 1. The lower protrusion punch is lowered when the punch and the upper protrusion punch are lowered after forming the lower deep hole,
The molding apparatus according to claim 1 or 2. When the round bar material formed by axial drawing is moved upward to the predetermined position together with the punch, and before the lower punch is raised,
The lower part of the shaft drawing part of the round bar material which is formed by shaft drawing is in contact with the inner peripheral surface of the through hole for the sleeve,
There is a gap between the upper part of the shaft throttle part and the inner peripheral surface of the second die recess,
The shaping | molding apparatus as described in any one of Claims 1-3. The punch descends and axially draws the upper part of the round bar material with the punch recess having an opening narrower than the upper end surface of the round bar material,
The shaping | molding apparatus as described in any one of Claims 1-4. A molding method for molding a shaft forged part from a round bar material,
A punch having a punch recess opened downward when the axial direction of the shaft object forged part is the vertical direction;
A rod-shaped upper protrusion punch fitted into an upper protrusion punch through hole penetrating from the upper surface of the punch to the bottom surface of the punch recess;
A die first recess opened upward, a die second recess opened in the bottom surface of the die first recess, and an opening penetrating from the bottom surface to the bottom surface of the die second recess and narrower than the lower end surface of the round bar material. A die having a through hole for a sleeve,
A cylindrical sleeve fitted with the through-hole for sleeve and having a through-hole for lower protrusion punching through in the axial direction;
A rod-shaped lower protrusion punch fitted in the through hole for the lower protrusion punch, and
Provided,
Lowering the punch by lowering the lower part of the round bar material disposed between the punch and the die into the through-hole for sleeve and axial drawing molding;
Moving the round bar blank formed by axial drawing to a predetermined position together with the punch by raising the sleeve; and
Forming a lower deep hole in the lower end surface of the round bar material moved to the predetermined position by raising the lower thrust punch; and
Pressing the round bar material formed with the lower deep hole by lowering the punch, and upsetting the round bar material into the first die recess and the second die recess;
Forming the upper deep hole on the upper end surface of the round bar material formed with the lower deep hole by lowering the upper thrust punch; and
A molding method comprising: The step of performing the upsetting and the step of forming the upper deep hole are as follows:
While lowering the punch, it is performed by lowering the upper thrust punch at a lowering speed faster than the punch,
The molding method according to claim 6. Lowering the lower protrusion punch when lowering the punch and the upper protrusion punch after forming the lower deep hole,
The molding method according to claim 6 or 7. After the step of moving upward to the predetermined position, and before the step of forming the lower deep hole,
The lower part of the shaft drawing portion of the round bar material which is formed by shaft drawing is in contact with the inner peripheral surface of the through hole for the sleeve,
A gap is provided between the upper portion of the shaft restricting portion and the inner peripheral surface of the second die recess,
The shaping | molding method as described in any one of Claims 6-8. Further comprising the step of axially drawing the upper portion of the round bar material at the punch recess having an opening narrower than the upper end surface of the round bar material by lowering the punch.
The shaping | molding method as described in any one of Claims 6-9.

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