JP4563716B2 - Forging apparatus and forging method - Google Patents

Description

The present invention, forging device formed by forging, and to a forging method.

  Conventionally, locking members such as nails, bolts, screws, etc., have formed a bulge-shaped head at one end of the rod-like portion extended into a rod-like shape that is larger than the diameter of the rod-like portion. When the locking member is made of a metal such as stainless steel or aluminum alloy, it is formed by forging using a forging device.

In other words, the first mold is provided with an insertion hole into which the rod-shaped portion of the metal body that becomes the rod-shaped portion of the locking member is inserted, and the first mold is a punch while inserting the rod-shaped portion of the metal body into the insertion hole. The two molds are pressed against the first mold with a predetermined pressure to form the head, and a finishing process is performed as necessary to form a locking member having a predetermined shape (for example, Patent Documents) 1).
JP 2003-211122 A

  However, in the above-described locking member, when the locking member is damaged due to a large stress acting on the boundary region between the rod-shaped portion and the head at the time of use, the boundary between the rod-shaped portion and the head is always used. It was an area.

  In order to prevent such a breakage of the locking member, a sufficient margin is usually obtained by using a rod having a large diameter, but the locking member is used. With the demand for lighter products, there has been a growing demand for smaller and lighter locking members, making it difficult to obtain a sufficient margin.

  Therefore, in recent years, a margin is obtained by improving the strength of the metal body serving as the locking member, but the problem is that the metal body with improved strength is not accepted by the market because of its high cost. was there.

  In view of the current situation, the present inventors who developed a technique that can improve the strength of the metal body by refining the metal structure, by forming a locking member using the technique, A technique for forming a locking member with improved margin at low cost has been developed, and the present invention has been achieved.

The forging device of the present invention is a forging device that forges a metal body to form a bolt base having a head and a rod-like portion, and is provided with a receiving hole for forming the rod-like portion of the bolt base. , A second mold provided with a head forming recess for forming the head of the bolt base, and at least one of the first mold and the second mold When the polymerization is performed with a rotating plate interposed between them when rotating, at least one of the first mold and the second mold is placed on the other along the overlapping surface. A rotation means that rotates relative to each other, and a rotation plate that rotates when at least one of the first mold and the second mold rotates to interpose them, Along the overlapping surface, at least one of the first mold and the second mold To when you rotate relative one to the other, and a pressing means for pressing the rod-like portion of the inserted the metal body in the housing bore toward the second die, said rotating plate A metal body insertion hole through which the metal body is inserted, and a non-contact surface that does not contact the metal body on the inner peripheral surface of the metal body insertion hole. By rotating at least one of the second mold relative to the other, the boundary between the rod-shaped portion and the head that does not contact the inner peripheral surface of the metal body insertion hole of the rotating plate A refined region of the metal structure can be formed.

In the forging method of the present invention, a first mold provided with an accommodation hole for forming a rod-shaped portion, a second mold provided with a head forming recess for forming a head, polymerized, the first at least one of the mold and the second mold using a rotating plate which rotates along with the time of rotation, the rod-shaped portion and a head forged metal body And forming a bolt base having a metal body insertion hole through which the metal body is inserted, and contacting the metal body with an inner peripheral surface of the metal body insertion hole. A non-contact surface that is not allowed to be provided is provided, and a rotating plate that rotates when either one of the first mold and the second mold rotates is interposed , and polymerization is performed along the overlapping surface. The at least one of the first mold and the second mold is relatively set with respect to the other When brought into rolling presses the rod-shaped portion of the inserted the metal body in the housing bore toward the second mold, the rod-shaped portion which does not contact the inner peripheral surface of the metal body insertion hole of the rotating plate And a refined region of the metal structure is formed in the boundary region of the head.

Furthermore, the following points are also characteristic. That is,
The boundary region between the rod-shaped portion and the head that is twisted by rotating the rotating plate together with the second mold is tapered.

According to invention of Claim 1, it is a forging apparatus which forges a metal body and forms the volt | bolt base | substrate which has a head and a rod-shaped part, Comprising: The accommodation hole for forming the rod-shaped part of a volt | bolt base | substrate was provided. a first mold, a second mold provided with a head forming recess for forming the head of the bolt body, the at least one of the first mold and the second mold When polymerization is performed with a rotating rotating plate interposed between the rotating plates, at least one of the first mold and the second mold is relative to the other along the overlapping surface. The rotation means for rotating the metal body, the metal body can be twisted with rotation by the rotation means, and the metal structure of the metal body can be refined by shearing strain accompanying the twist. Only the twisted part can improve the strength. Therefore, it is possible to improve the partial strength such as the boundary region between the rod-like portion and the head portion of the bolt base body, which is a forged molded product, and to improve the margin of the forged molded product without increasing the manufacturing cost. it can. In addition, the rotating plate is provided with a metal body insertion hole through which the metal body is inserted, and a non-contact surface that does not contact the metal body is provided on the inner peripheral surface of the metal body insertion hole. By adjusting the size of the contact surface, the region of the metal body to be twisted, that is, the size of the refined region where the metal structure of the metal body is refined can be adjusted. Therefore, since a miniaturized region having a desired size can be formed, the strength improvement can be adjusted. In addition, the first mold and the second mold are polymerized with a rotating plate interposed between them when the first mold and the second mold rotate, and the first mold is formed along the polymerization surface. type and at least one of said second die relative rotation to Rutoki relative to the other, to press the rod-like portion of the inserted metal body accommodating hole in the direction of the second mold By providing the pressing means, it is possible to prevent breakage in a region where the metal body is twisted when the metal body is twisted by the rotation of the second mold by the rotating means.

According to invention of Claim 2, the 1st metal mold | die provided with the accommodation hole for forming a rod-shaped part, and the 2nd metal mold | die provided with the recessed part for head formation for forming a head part , polymerized in the meantime, with the rotating plate at least one of said first mold and said second mold is rotated along with the time of rotation, the rod-like portion by forging the metal body A forging method for forming a bolt base having a head and a head, wherein the rotating plate is provided with a metal body insertion hole through which the metal body is inserted, and a metal body and an inner peripheral surface of the metal body insertion hole A non-contact surface that is not brought into contact is provided, and a rotating plate that rotates when one of the first mold and the second mold rotates is interposed for polymerization, and along the overlapping surface And rotating at least one of the first mold and the second mold relative to the other. The metal body can be twisted by forming a refined region of the metal structure in the boundary region between the rod-like portion not contacting the inner peripheral surface of the metal body insertion hole of the rotating plate and the head, and accompanying the twist Since the metal structure of the metal body can be refined by shear strain, the strength can be improved only in the twisted portion. Therefore, it is possible to improve the partial strength such as the boundary region between the rod-like portion and the head portion of the bolt base body, which is a forged molded product, and to improve the margin of the forged molded product without increasing the manufacturing cost. it can. Furthermore, by adjusting the size of the non-contact surface, it is possible to adjust the size of the region of the metal body to be twisted, that is, the size of the refined region in which the metal structure of the metal body is refined. Therefore, since a miniaturized region having a desired size can be formed, the strength improvement can be adjusted. Further, the first mold and the second mold are polymerized with a rotating plate interposed between them when the first mold and the second mold rotate, and the first mold and When at least one of the second mold is rotated relative to the other, by pressing the rod-shaped portion of the metal body inserted into the accommodation hole in the direction of the second mold , When the metal body is twisted by rotating the second mold, it is possible to prevent breakage in a region where the metal body is twisted.

According to the invention of claim 3, wherein, in the forging method according to claim 2, and a boundary area of the bar-shaped portion and the head is rotated twisting by rotating the rotary plate together with the second mold was a tapered shape As a result, it is possible to prevent the metal body from being broken when it is twisted, and to enlarge the refined region in which the metal structure of the metal body is refined.

  In the forging device and the forging method of the present invention, not only forging a bolt base body having a head portion and a rod-like portion, which is a metal body to be forged, into a predetermined shape, but also a boundary between the rod-like portion and the head portion that is a part thereof. A refined region is formed by refining the metal structure of the region, and the strength of the forged product is improved in the refined region.

  That is, in a bolt base that is a forged molded product formed by forging, the location of occurrence of damage is generally constant when breakage occurs, and the boundary between the rod-shaped portion of the bolt base that is the location of the occurrence of damage and the head Since it has the same effect as improving the overall strength of the bolt base that is a forged product by improving the strength of the region, in the present invention, the rod-shaped portion of the bolt base that is the portion where the breakage occurred By making the boundary region between the head and the head a finer region, the strength is partially improved, and the strength of the bolt base body, which is a forged product, is improved.

In particular, the refined region is a polymerization surface where the first mold and the second mold are polymerized with each other when the metal body is forged by polymerizing the first mold and the second mold. Along with this, the metal body is twisted by rotating at least one of the first mold and the second mold relative to the other, and the metal body is subjected to shear strain along with the twist. It is formed by making the metal structure finer.

  In this way, shear strain can be easily generated in the metal body by rotating at least one of the first mold and the second mold relative to the other. Thus, the metal structure can be made finer, so that a fine region can be formed without increasing the manufacturing cost, and the strength of the metal body in the fine region can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram of the manufacturing process of this embodiment. The present embodiment is a bolt manufacturing process, particularly a bolt base forming process by forging before the thread cutting process.

  In particular, in this embodiment, the bolt base is formed in three stages: a temporary forming step in FIG. 1A, a refined region forming step in FIG. 1B, and a main forming step in FIG. It is made using a three-stage part former.

  In the temporary forming step, the first temporary mold 11a and the second temporary mold 11a that is movable forward and backward with respect to the first temporary mold 11a and is in contact with the first temporary mold 11a. The metal body M is temporarily formed into a predetermined shape by pressing and forging the metal body M with 12a.

That is, the first mold 11a for temporary molding is provided with a receiving hole 13a for forming a rod-shaped portion of the bolt base, and the second mold 12a for temporary molding is used for forming the head of the bolt base. A head forming recess 14a is provided. Further, a temporary molding piston 15a that advances and retreats along the accommodation hole 13a is inserted into the accommodation hole 13a of the first temporary molding die 11a.

  Then, the metal base M is pressed and forged by the first temporary mold 11a and the second temporary mold 12a to forge the bolt base, and the second temporary mold 12a is temporarily mounted. The metal body M, which is separated from the first molding die 11a and is temporarily molded by the temporary molding piston 15a, is extruded and conveyed to the refined region forming step. The form of conveyance of the metal body M between the processes may be an appropriate form. For example, the metal body M is adsorbed to the second mold 12a for temporary molding, and the metal body M is moved to the next process by the second mold 12a for temporary molding. You may convey to a refinement | miniaturization area | region formation process.

In the refined region forming step (b) , which is the main part of the present invention, the refined region forming first mold 11b and the refined region forming first die 11b can be moved forward and backward and refined. when pressing the metal body M by the second mold 12b for refined region formed which polymerize first mold 11b for regions forming, first for refined region forming the second mold 12b for refined region formed 1 A refined region m in which the metal structure is refined is formed in the metal body M by rotating the mold 11b by a predetermined angle.

In particular, the first mold 11b for forming a miniaturized region is also provided with a receiving hole 13b into which the rod-shaped portion of the metal body M that becomes the rod-shaped portion of the bolt base is inserted. A rotating plate 11b ′ that is rotatable about the accommodation hole 13b as a center of rotation is interposed at the overlapping surface portion of the mold 11b with the second mold 12b for forming a refined region.

Second if the mold 12b is rotated by polymerization in the first mold 11b for refined region formed, the first mold 11b for rotation plate 11b 'is refined region formed interposed therebetween for refined region formed By rotating together, the second mold 12b for forming the miniaturized region can be smoothly rotated, and the miniaturized region m can be formed by reliably twisting the metal body M by a predetermined amount in a short time. .

The rotation of the second mold 12b for forming a miniaturized area with respect to the first mold 11b for forming the miniaturized area causes the second mold 12b for forming the miniaturized area to be polymerized to the first mold 11b for forming the miniaturized area. Alternatively, it may be performed after the second mold 12b for forming a miniaturized region is brought into contact with the first mold 11b for forming a miniaturized region with a predetermined pressing force.

In the present embodiment, an operation piece (not shown) is provided on the outer surface of the second mold 12b for forming a miniaturized region, so that the second mold 12b for forming the miniaturized region 12 When the operation piece is brought close to the mold 11b for polymerization , the operation piece is slid along a rotating operation body (not shown) having an inclined surface of a predetermined angle, thereby forming a second refined region forming second. While the mold 12b is rotated, the first mold 11b for forming a miniaturized region is polymerized . Further, when the second mold 12b for forming a miniaturized region is separated from the first mold 11b for forming the miniaturized region, the second mold 12b for forming the miniaturized region is provided to rotate in the reverse direction. The operating piece is returned to the initial position by an elastic body such as a biasing spring (not shown). Note that the rotation operation mechanism of the second mold 12b for forming the miniaturized region is not limited to the above-described mechanism, and an appropriate mechanism can be used.

  The rotating plate 11b ′ is provided with a metal body insertion hole 16 through which the metal body M is inserted, and an inner peripheral surface of the metal body insertion hole 16 is a non-contact surface 17 that does not contact the metal body M. That is, the inner diameter of the metal body insertion hole 16 is larger than the diameter dimension of the metal body M so that the non-contact surface 17 does not contact the metal body M.

As described above, the rotating plate 11b ′ and the metal body M are not in contact with each other in the rotating plate 11b ′ portion, so that the mold 11b, Only the non-contact area of the metal body M not in contact with 12b can be twisted.

  That is, the metal body M is in contact with the portion 13b of the first mold 11b for forming the miniaturized region that is in contact with the receiving hole 13b and the head forming recess 14b provided in the second mold 12b for forming the miniaturized region. In the portion, when the frictional force acts as a restraining force, the first metal mold 11b for forming the miniaturized area 11b and the second mold for forming the miniaturized area of the metal body M accompanying the rotation of the second mold 12b for forming the miniaturized area. Although no displacement in the rotational direction with respect to the two molds 12b occurs, no restraining force acts in the non-contact area, so that the metal body M is twisted with the rotation of the second mold 12b for forming the miniaturized area. Will be.

  Then, the metal structure can be refined by generating shear strain in the metal body M as the metal body M is twisted, and the refined region m can be formed.

  In the present embodiment, as shown in FIG. 1B, the non-contact surface 17 is tapered by expanding the metal body insertion hole 16 toward the second mold 12b for forming a fine region. However, the non-contact surface 17 is not limited to such a tapered shape, and may have an appropriate shape. In particular, a part of the inner peripheral surface of the metal body insertion hole 16 may be in contact with the metal body M, and by adjusting the size of the non-contact surface 17, the second mold for forming a miniaturized region is used. The region of the metal body M to be twisted with the rotation of 12b can be adjusted.

  Therefore, since the size of the miniaturized region m can be adjusted, the miniaturized region m having a desired size can be formed, and the strength improvement can be adjusted.

  In particular, the refined region m is formed in a portion that is easily damaged, such as the boundary region between the rod-like portion of the bolt base and the head as in the present embodiment, thereby improving the overall strength. The same effect can be obtained.

  The rotation angle of the second mold 12b for forming a refined region may be of a level that can generate a shear strain capable of miniaturizing the metal structure of the metal body, and the desired refinement level of the metal structure and the rotating plate 11b. It is determined from the thickness dimension of 'or the area of the non-contact surface 17, and it is usually sufficient to rotate at least 10 ° or more, preferably 30 ° or more.

  Further, the accommodation hole 13b of the first mold 11b for forming a refined region is provided with a piston 15b for forming a refined region that advances and retreats along the accommodation hole 13b.

The refined region formed piston 15b is above the second mold 12b for refined region formed with the polymerization of the first mold 11b for refined region formed with the second mold 12b for refined region formed When rotating in this manner, the metal body M is pressed in the direction of the second mold 12b for forming a refined region.

  As described above, when the metal body M is pressed by the fine region forming piston 15b when the micro region is formed, the metal body M is twisted with the rotation of the second mold 12b for forming the micro region. It can prevent that a fracture | rupture arises in the area | region which is.

  In the present embodiment, the second mold 12b for forming a miniaturized region is rotated with respect to the first mold 11b for forming a miniaturized region. You may comprise so that it may rotate, and also you may comprise so that both the 1st metal mold | die 11b for refinement | miniaturization area | region formation and the 2nd metal mold | die 12b for refinement | miniaturization area | region formation may each be rotated.

  After the metal body M is pressed and forged by the first mold 11b for forming the refined area and the second mold 12b for forming the refined area, the refined area m is formed on the bolt base, and then the refined area is formed. The second metal mold 12b is separated from the first metal mold 11b for forming the refined region, and the metal body M is pushed out by the piston 15b for forming the refined region, and conveyed to the main forming step.

In the main molding step, the first metal mold 11c for main molding and the second metal mold for main molding that can be moved forward and backward with respect to the first metal mold 11c for main molding and are polymerized to the first metal mold 11c for main molding. By pressing and forging the metal body M with 12c, the metal body M is finally formed into a predetermined shape.

  That is, the first molding die 11c is provided with a receiving hole 13c for forming the rod-shaped portion of the bolt base, and the second molding die 12c is a head for forming the head of the base. A part forming recess 14c is provided. Further, a main forming piston 15c that advances and retreats along the accommodating hole 13c is inserted into the accommodating hole 13c of the first main mold 11c.

  Then, the metal body M is pressed by the first metal mold 11c and the second metal mold 12c for main molding, and further, the metal body M is pressed by the main molding piston 15c and forged, thereby forging the bolt base. The main molding is performed, the second metal mold 12c for main molding is separated from the first metal mold 11c for main molding, and the metal body M which is finally molded by the main molding piston 15c is discharged.

  In the present embodiment, the formation is performed in three stages, that is, a temporary forming process, a miniaturized region forming process, and a main forming process. Alternatively, more steps may be provided as necessary.

  In the present embodiment, each of the second molds 12a, 12b, and 12c is movable forward and backward with respect to each of the first molds 11a, 11b, and 11c. Thus, the first molds 11a, 11b, and 11c may be freely advanced and retracted.

  As another embodiment, forging is performed in three stages: a temporary forming step shown in FIG. 2 (a), a refined region forming step shown in FIG. 2 (b), and a main forming step shown in FIG. 2 (c). You may comprise.

  In the temporary forming step, a first mold 21a for temporary forming provided with a receiving hole 23a for forming a rod-shaped portion of the bolt base and a head forming recess 24a for forming the head of the bolt base are provided. The bolt body is temporarily formed by pressing and forging the metal body M ′ with the second temporary mold 22a, and the second temporary mold 22a is separated from the first temporary mold 21a. Thus, the metal body M ′ temporarily formed by the temporary forming piston 25a is extruded and conveyed to the miniaturized region forming step.

  In particular, the first mold 21a for temporary molding is formed with a taper-shaped widened portion 28 at the end of the accommodation hole 23a, so that the first mold 21a for temporary molding and the second mold 22a for temporary molding are provided. When the metal body M ′ is pressed and forged, the boundary region between the rod-shaped portion and the head portion of the bolt base that is twisted in the subsequent refinement region forming step is gradually moved from the rod-shaped portion toward the head portion. An enlarged taper shape is formed.

  As described above, the metal body M ′ provided with the tapered enlarged diameter portion is conveyed to the refined region forming step, and the refined region m ′ is formed in the enlarged diameter portion in the refined region forming step.

  In the refined region forming step, the rod-shaped portion of the bolt base is inserted into the accommodation hole 23b of the first refined region forming mold 21b provided with the rotating plate 21b ', and the refined region provided with the head forming recess 24b. While pressing the metal body M ′ by the second mold 22b for forming and pressing the metal body M ′ by the piston 25b for forming the miniaturized area inserted into the accommodation hole 23b of the first mold 21b for forming the miniaturized area The second refined region forming mold 22b is rotated by a predetermined angle with respect to the first refined region forming mold 21b, whereby the refined region m ′ in which the metal structure is refined in the metal body M ′. Is forming.

  In particular, the rotating plate 21b ′ has a thickness dimension substantially equal to the height dimension of the enlarged diameter portion provided in the metal body M ′, and the rotating plate 21b ′ is a metal through which the metal body M ′ is inserted. The body insertion hole 26 is provided, and the inner peripheral surface of the metal body insertion hole 26 is a non-contact surface 27 that does not contact the metal body M ′.

After forming the refined region m ′ in the enlarged diameter portion provided in the metal body M ′ in the refined region forming step,
In the main forming process, the bolt base is finally formed.

  In the main molding step, the metal body M ′ is pressed with the first main mold 21c having the accommodation hole 23c and the second main mold 22c having the head forming concave portion 24c, and the main body M ′ is pressed. The metal body M ′ is forged into a predetermined shape by pressing and forging the metal body M ′ with the main molding piston 25 c inserted into the housing hole 23 c of the first molding die 21 c.

  In this way, by forming the portion where the miniaturized region m ′ in the bolt base is tapered, the metal body M ′ can be prevented from being broken when the metal body M ′ is twisted, and the metal body M ′ The “miniaturized region m” can be enlarged.

It is a schematic explanatory drawing explaining the forging method which concerns on this invention. It is a schematic explanatory drawing explaining the forge method of other embodiment.

M, M 'metal body
m, m 'refined region
11a, 21a First mold for temporary molding
12a, 22a Second mold for temporary molding
13a, 23a receiving hole
14a, 24a Head forming recess
15a, 25a Temporary molding piston
11b, 21b First mold for forming miniaturized regions
11b ', 21b' rotating plate
12b, 22b Second mold for forming miniaturized regions
13b, 23b receiving hole
14b, 24b Head forming recess
15b, 25b Piston for forming miniaturized area
16,26 Metal body insertion hole
17,27 Non-contact surface
11c, 21c 1st mold for main molding
13c, 23c receiving hole
12c, 22c 2nd mold for main molding
14c, 24c Head forming recess
15c, 25c Main molding piston

Claims (3)

A forging device that forges a metal body to form a bolt base body having a head portion and a rod-like portion,
A first mold provided with an accommodation hole for forming the rod-shaped portion of the bolt base;
A second mold provided with a head forming recess for forming the head of the bolt base;
When the rotation plate rotating with at least one of the first mold and the second mold rotating is interposed between the first mold and the second mold, the first mold is formed along the overlapping surface. Rotating means for rotating at least one of the second mold and the second mold relative to the other;
A rotating plate that rotates as at least one of the first mold and the second mold rotates is interposed between the first mold and the first mold, and the first mold is formed along the overlapping surface. type and at least one of said second die relative rotation to Rutoki relative to the other, the direction of the rod-like portion of the inserted the metal body into the accommodating hole of the second mold and a pressing means for pressing on,
With
The rotating plate is provided with a metal body insertion hole through which the metal body is inserted, and the inner surface of the metal body insertion hole is provided with a non-contact surface that does not contact the metal body. By rotating at least one of the mold and the second mold relative to the other, the rod-shaped portion that does not contact the inner peripheral surface of the metal body insertion hole of the rotating plate and the head A forging device characterized in that a refined region of a metal structure can be formed in a boundary region. A first mold provided with an accommodation hole for forming a rod-shaped part, a second mold provided with a recess for forming a head part for forming a head part, and polymerization between them, the first mold of at least one of the mold and the second mold using a rotating plate which rotates along with the time of rotation, forming a bolt body having a rod portion and a head forged metal body A forging method to perform,
The rotating plate is provided with a metal body insertion hole through which the metal body is inserted, and a non-contact surface that does not contact the metal body is provided on the inner peripheral surface of the metal body insertion hole.
The first mold and the second mold are polymerized by interposing a rotating plate that rotates as one of the first mold and the second mold rotates, and along the overlapping surface, the first mold When the at least one of the second mold and the second mold are rotated relative to the other, the rod-shaped portion of the metal body inserted in the accommodation hole is directed in the direction of the second mold. pressed,
Forging method characterized by forming a fine region of the metal structure in the boundary area of the bar-shaped portion and the head portion without abutting against the inner peripheral surface of the metal body insertion hole of the rotating plate.   The forging method according to claim 2, wherein a boundary region between the rod-shaped portion and the head that is twisted by rotating a rotating plate together with the second mold is tapered.

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