JPH01180746A - Method for forging projection part of forging part having u or v shaped lug part and forging die usable therefor - Google Patents

Abstract

PURPOSE:To improve the accuracy of a product and to reduce the cost by forming on a forging die the space part for forming a projection part, a lug part forming face and axial part forming face are constrained by a constraint die face as well and executing upsetting on the axial part. CONSTITUTION:A movable die 11 is made up of a die part 37 and die 38 and the space part 43 for forming a forging projection part is formed on the lower part end part of the die 38. The axial part of the preform W3 having an U shaped lug part 3 is set in the cavity 39 of the die 38 of the mobile die 11, an upper bolster 27 is descended and a punch die 31 is advanced downward. In this case, the inner opposing face 3a, tip face 3c and axial part 1 of the lug part 3 of the preform W3 are respectively constrained by constraint dies 40, 26. The projection part is formed via the die 38 and punch die 31 with the axial part 1 being upset in the axial direction. The accuracy of a product is improved and the cost is reduced because the project. ion part is formed by cold forging by constraining the lug part 3 and axial part 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forging a convex portion of a forged product having U-shaped or seven-shaped ears, and a forging die that can be used in this method.

[Prior Art] Conventionally, for example, a steering yoke has been provided as a forged product having a U-shaped ear portion and an integral shaft portion. After machining, the steering yoke is
As shown in FIGS. 5 to 16, a U-shaped ear portion 100,
The center line 10 of the ear 1oO is geared to the middle part of the ear 100.
It has a shaft part 102 in the same direction as 1. This steering yoke has a shaft hole 103 in a shaft portion 102, and a spline is formed in the shaft hole 103. A spline portion at the tip of the shaft used for the steering yoke is inserted into this spline.

A mounting protrusion 104 is formed on the shaft portion 102 of the steering yoke to ensure the fitting between the splines of the steering yoke and the splines at the tip of the shaft of the steering mechanism. For this installation, a bolt insertion hole 105 and a slit 106 are formed in the protrusion 104, and for installation partitioned by the slit 106, a screw hole 107 is formed on one side of the protrusion 104, and the bolt is inserted into the screw hole 107.
The shaft of the steering mechanism is attached to the steering yoke by screwing and tightening the shaft.

Therefore, the shaft portion of the steering yoke blank material, which is the raw material before machining of the steering yoke, has a protrusion 10 attached to it.
A convex portion forming 4 is formed. In forming the convex portion on the shaft, conventionally, the formed material is hot forged in the thickness direction of the formed material, that is, in the direction of the arrow Y shown in FIG. A convex portion was formed.

Incidentally, in recent years, attempts have been made to form steering yoke blanks by cold forging, which can significantly omit the machining process due to less material loss and good dimensional accuracy.

[Problems to be Solved by the Invention] The present invention does not adopt a method of forging a material in the thickness direction of the material, but instead forms a material in a U-shape or V-shape to be suitable for cold forging. By upsetting and forging a material having a shaped ear and a shaft along the center line of the material in the axial direction of the material's shaft, it is possible to create a material with a long or short shaft. To provide a forging method suitable for forming a forging convex part on a shaft part even when the forging part is formed, and especially for forming a forging convex part bulging from the shaft part in a direction perpendicular to a plane connecting the ears. With the goal.

Furthermore, the present invention can be used in the forging method described above! l12
The purpose is to provide modeling.

[Means for Solving the Problems] The method for forging a convex portion of a forged product having a U-shaped or 7-shaped ear portion according to the present invention includes a method for forging a convex portion of a forged product having a U-shaped or 7-shaped ear portion, and an intermediate portion between the U-shaped or 7-shaped ear portion. A metal material is connected to the material and has a shaft extending in the same direction as the center line of the material, and a restraining type surface that corresponds to the shape forming the material's material and is capable of restraining the material. At the same time, a forging die having a space for forming a convex part between it and a part of the outer surface in the axial direction, which forms the shaft of the material, is used to form the ear portion of the material. At the same time, the surface forming the shaft part other than the surface corresponding to the space part is restrained by the restraining mold surface of the forging mold, while suppressing the deformation of the ear part. The part is upset in the axial direction of this, and a part of the flesh of the shaft part flows into the space for forming the convex part, and the FU-shaped convex part that bulges out in the direction intersecting the axis of the shaft part is formed with the shaft part. It is characterized by being integrally formed.

The method of the present invention is usually carried out by cold forging, which has good material yield and dimensional accuracy and can omit machining.

However, in some cases, warm forging or hot forging may be used.

The forging die of the present invention is used in the above-mentioned convex part fI manufacturing method, and is arranged in a row between the 0-shaped or V-shaped ears and the intermediate part of the ears in the same direction as the center line of the ears. A forging die that presses a metal material having a shank, a base with a knockout hole, and a forging die that is inserted into the knockout hole in the base and located on the opposite side of the ear of the shank of the material. A knockout type has a first restraint type surface that has a shape corresponding to the shaft end surface and restrains the shaft end surface, and a punch type has a punch type surface that has a shape corresponding to the inner surface of the ear and restrains the inner surface. , a second restraining type surface that has a shape corresponding to the rear surface of the ear part of the raw material and restrains the rear surface, and a shape corresponding to the outer surface extending along the axial direction of the shaft part of the raw material. A movable mold having an iJ3 restraint mold surface that restrains the outer surface of the rice cake, and a mold surface for forming a convex portion that partitions a space for forming a convex portion between a part of the outer surface of the shaft portion of the material. and a biasing member that is interposed between the movable mold and the base and urges the movable mold toward the punch mold.The punch mold is moved forward while resisting the biasing force of the biasing member, and the punch mold is The punch mold surface and the movable second restraint mold surface restrain the ear portion of the formed material while the shaft portion is upset in the axial direction of the shaft portion.

[Function] With the dimensions of the present invention, part of the meat of the shaft that has flowed into the space for forming the convex part due to upsetting is defined by the mold surface that partitions the space, thereby forming the forged convex part. be done.

[Example] Hereinafter, an example in which the present invention is applied to a roughly shaped steering yoke will be described with reference to FIGS. 1 to 14.

The steering yoke blank W3 before the method of the present embodiment is shown in FIG. 4 as a plan view and in FIG. 5 as a side view. The steering yoke blank W4 after carrying out the method of this example is shown in FIG. 6 as a plan view and in FIG. 7 as a side view. A forged convex portion 2 is formed on the shaft portion 1' of the steering yoke blank W4 after carrying out the method of this embodiment. The forged convex portion 2 protrudes in a direction substantially perpendicular to a plane connecting a pair of ears 3' forming a letter 0 shape.

First, for convenience of explanation, a method for forming the steering yoke blank W3 shown in FIGS. 4 and 5 will be explained, then a forging die used in the convex forging method according to this embodiment will be explained, and then , the navel forging method of this example will be explained.

First, in forming the steering yoke blank material W3 shown in FIGS. 4 and 5, the round bar material W1 shown in FIG.
After the surface of the round bar W1 is subjected to bonding treatment, the round bar material W1 is upset in the axial direction using a rough forging die and forged. Note that low carbon steel and medium carbon steel can be used as the material for the round bar material W1. A rough material W2 having a substantially U-shaped rough edge portion 5 and a shaft portion 6 as shown in FIGS. 2 and 3 is forged by upsetting forging. Further, the rough material W2 is heated to perform intermediate annealing to soften the work-hardened rough material edges 5. Thereafter, the scale of the rough ground rope material w2 is removed by shot blasting, and the rough ground material W2 is subjected to bonding treatment.

Then, the rough ground material W2 is forged with another forging die to extrude the rough ground ear portion 5 backward, thereby forming the U-shaped ear portion 3.
form. In this step, the shaft portion 6 of the rough material W2 becomes the shaft portion 1 with almost no change in length. A plan view of the steering yoke blank W3 that has undergone this process is shown in FIG.
A side view is shown in FIG. As shown in FIGS. 4 and 5, the steering yoke material W3 is connected to the O-shaped ear portion 3 and the intermediate portion of the ear portion 3, and extends in the same direction as the center line W of the ear portion 3. It has a shaft part 1. Here, Figures 4 and 5
In the steering yoke blank W3 shown in the figure, the inner surfaces 3a of the ears 3 face each other, and the rear surfaces 3b of the ears 3 face each other. The tip surface 3c of the ear portion 3 is formed into an arcuate surface. Steering yoke material W
The outer surface 1a of the shaft portion 1 of No. 3 extends in the axial direction. The axial end surface of the shaft portion 1 of the steering yoke blank W3 is defined as a shaft end surface 1b.

Next, the mold used in the navel forging method of this embodiment will be explained with reference mainly to FIGS. 8, 9, and 14. Here, the part (xl) shown in FIG. 8 shows the state before the punch die 31 is driven in, and the part (X2) shows the state after the punch die 31 is driven in. This forging die is
This is a forging die that presses the steering yoke blank W3 to form a forging convex portion 2 on the outer surface 1a of the shaft portion 1. This forging die includes a base 8, a knockout die 9, a punch die 31, a movable die 11, and a biasing member 47. The base 8 is attached to a lower bolster 13. The base 8 is composed of a die pressure plate 14, a lower mold pressure plate 15, a holder 16, and a holding member 17. A plurality of biasing member holding holes 19 are formed in the upper surface of the die pressure plate 14 . The die pressure plate 14 is mounted on the lower die pressure plate 15. A first knockout hole 2o is formed in the center of the die pressure plate 14. Further, a second knockout hole 21 is formed in the center of the lower die pressure plate 15.

The second knockout hole 21 has a smaller diameter than the first knockout hole 20. The holder 16 has a cylindrical shape and surrounds the die pressure plate 14 and the lower die pressure plate 15. Pressing member 17
is provided on the upper surface of the holder 16. Presser member 1
7 has a ring shape and functions as a stopper.

The knockout mold 9 is formed of a first knockout mold 23 and a knockout pin 24. A first knockout mold 23 is inserted into the first knockout hole 20 so as to be movable up and down, and a knockout bin 24 is inserted into the second knockout hole 21.
is inserted so that it can be raised and lowered. 1st knockout type 2
A first restraining mold surface 26 is formed at the tip of the holder 3 . The first constraint mold surface 26 is located on the opposite side of the ear portion 3 of the shaft portion 1 of the steering yoke blank W3. The first constraint mold surface 26 is
The shape is substantially symmetrical to the shaft end surface 1b of the shaft portion 1 of the steering yoke blank W3.

An upper bolster 27 is provided above the die pressure plate 14. The upper bolster 27 has a base 25, a punch base 28, two upper pressure plates, and a punch holder 30.
A punch die 31 is attached. As shown in FIGS. 10 to 13, the punch die 31 includes a first punch die 32 and a second punch die 33. As shown in FIGS. Then, the first punch die 32
The punch holder 30 is stacked with the second punch die 33 and the second punch die 33.
is attached to the punch holding hole 34 of. punch type 31
During operation, the first punch die 32 and the second punch die 33 are pressed together by the upper pressure plate 29 shown in FIG. The punch holder 30 is provided with a hole 36 for installation, and the flashing can be installed by inserting a bolt into the hole 36.
The punch holder 30 is attached to the bunch base 28. Here, the tip of the first punch die 32 is a first punch die surface 32a. As shown in FIG. 12, the first punch die surface 32a is U-shaped so as to be symmetrical with the inner facing surface 3a of the ear portion 3 of the steering yoke blank W3. Therefore, the first punch die 32a of the first punch die 32 can restrain the inner facing portion 3a of the U-shaped ear portion 3 of the steering yoke blank W3. A second punch die surface 32b is formed on both sides of the first punch die surface 32a. This second punch-type surface 32b presses the tip end portion 3C of the ear portion 3 of the steering yoke blank W3. As shown in Figures 9 and 11? The tip of the J2 punch die 33 protrudes below the first punch die surface 32a and serves as a second punch die surface 33a.

As shown in FIG. 8, the movable mold 11 is surrounded by a holder 16 and is provided above the base 8. Movable type 11
is formed of a mold part 37 having a central hole and a die 38 inserted into the central hole of the mold part 37 by shrink fitting.

Three cavities are formed in the center of the die 38 of the movable mold 11, which are hollow parts for the steering yoke blank W3. A second restraint mold surface 40 and a third restraint mold surface 41 are formed in the three cavities. Second constraint mold surface 4
0 has a shape that is substantially symmetrical with the rear surface 3b of the ear portion 3 of the steering yoke blank W3. Therefore, the second restraining mold surface 40 can restrain the rear surface 3b of the ear portion 3 of the steering yoke blank W3. The third restraint member 41 has a shape that is substantially symmetrical with the outer surface 1a extending along the axis of the shaft portion 1 of the steering yoke blank W3. Therefore, the third restraining mold surface 41 can restrain the outer surface 1a of the shaft portion 1 of the steering yoke blank W3. As shown in FIG. 9, the cavity 39 of the die 38 of the movable mold 11 has a mold surface 43 for forming a convex portion.
is formed. Here, as shown in FIG. 9, when the punch mold 31 is inserted into the cavity 39, the mold surface 43 for forming the convex portion and the second punch mold surface 33a of the second punch mold 33 form a convex portion. A space 44 for forming a section is defined.

Note that a biasing member holding hole 46 is formed in the lower surface of the mold portion 37 of the movable mold 11 .

A biasing member 47 is provided in the biasing member retaining hole 19 of the die pressure plate 14 and the biasing member retaining hole 46 of the movable mold 11. The biasing member 47 is an elastically contractible spring member, and is interposed between the movable mold 11 and the base 8 to urge the mold part 3 of the movable mold 11.
7 is urged upward, so that the stepped portion 37a of the mold portion 37
When the punch die 31 is not in operation, it is in contact with the presser member 17 as shown in FIG. 8 (x1). Therefore, the movable mold 11 is floating above the die pressure plate 14 of the base 8 by a distance t. Here, in order to ensure the biasing force, the cross section of the wire forming the biasing member 47 is square.

Next, a case will be described in which the method for forging a convex portion according to this embodiment is carried out using the forging die described above.

That is, the shaft portion 1 of the steering yoke blank W3 shown in FIGS. 4 and 5 is shaped like a half (×1) in FIG.
It is set in the cavity 39 of the die 38 of the movable mold 11. With this setting in place, lower the upper bolster 27 using a cylinder device in the enclosure, etc., and insert the punch mold 3.
1 forward downward. Then, base 8, knockara 1
~ Since the mold 9 is in a fixed state, the first punch mold 32
The U-shaped inner facing surface 3a of the ear portion 3 of the steering yoke blank W3 is pressed by the punch die 32a, and the tip portion 3CfJ1 of the ear portion 3 is pressed by the second punch die surface 32b of the first punch die 32. ? 1 pressure is applied. As a result, the first punch die 3
2, the U-shaped inner facing surface 3a of the ear portion 3 is restrained, and the second punch surface 32b restrains the distal end portion 3C of the ear portion 3. At this time, the mold portion 37 of the movable mold 11 and the die 38 are strongly urged upward by the biasing member 47.

Therefore, the second constraint mold surface 40 of the die 38 of the movable mold 11
is strongly urged upward by 1, and is in close contact with the rear surface 3b of the ear portion 3 of the steering yoke blank W3, and the rear surface 3b of the ear portion 3 is restrained by the second restraining mold surface 40. There is. In addition, the shaft end surface 1b of the shaft portion 1 of the steering yoke blank W3
is in contact with the first restraining mold surface 26 of the knockout mold 9 and is restrained by the first restraining mold surface 26 .

While the inner facing surface 3a, the tip end surface 3C, and the rear facing surface 3b of the ear portion 3 of the steering yoke blank W3 are restrained, and the shaft end surface 1b of the shaft portion 1 is restrained, the biasing member 47 is further restrained. The punch die 31 is lowered while resisting the urging force of. Then, as shown in half (×2) of FIG. 8, the die 38 and the mold part 37 of the movable mold 11 collide with the upper surface of the die pressure plate 14. The ear portion 3 is securely restrained by the punch die 31 and the die 38 due to the collision. At this time, the first restraining mold surface 26 of the knockout mold 9 is in a fixed state. As a result, the shaft portion 1 of the steering yoke blank W3 is compressed in the axial direction, and upsetting is performed. Through this upsetting forging, the length of the shaft portion 1 in the axial direction is shortened, and a part of the thickness of the shaft portion 1 of the steering yoke blank W3 is used as a space for forming a convex portion. 1st towards 44th
It flows in the direction of arrow P shown in Figure 4. At this time, as shown in FIG. 14, due to the driving of the punch die 31, the second punch die surface 33a of the second punch die 33 also descends, so that the shape of the meat portion that has flowed into the space 44 for forming the convex portion is , defined by the second punch die surface 33a.

As a result of forging in this way, the steering yoke material W
A forged convex portion 2 that bulges out in a direction intersecting the axis is formed integrally with the shaft portion 1 of No. 3.

In this way, in this embodiment, when forming the forged convex portion 2, as described above, the steering yoke blank material W3 is
The inner facing surface 3a forming the letter-shaped ear portion 3 is formed by a punch type 31.
It is restrained by the first punch type surface 32a of the ear part 3.
The rear surface 3b of the die 38 is restrained by the second restraining die surface 4o. Therefore, when forming the forged convex portion 2, the deformation of the ear portion 3 of the steering yoke blank W3 is suppressed to the utmost, and even if the pressing force during upsetting forging is large, the ear portion 3 is hardly deformed. Not yet.

Further, in the forging die of this embodiment, when forging the a-shaped convex portion 2, the die 38 of the movable die 11 is urged upward by the urging member 47, and the forging convex portion 2 is formed. When the die 38 is in contact with the die pressure plate 14,
The ear portion 3 can be securely restrained. Therefore, the space 44 can be provided in the die 38 so as to protrude perpendicularly to the plane connecting the ears 3 of the steering yoke blank W3. Therefore, the forged convex portion 2 can be made to bulge out in a direction substantially perpendicular to the plane connecting the ear portions 3. In this respect, it is different from the conventional case in which the convex portion bulges out substantially parallel to the plane connecting the ear portions 100, as shown in FIGS. 15 to 17.

In this embodiment, after the forging of the forging convex portion 2 is completed, the punch die 31 is raised, and the knockout die 9 is raised by the drive of the cylinder device (not shown), and the steering yoke material W3 is moved into the cavity 3. Release from the mold.

[Effects of the Invention] According to the method of the present invention, a material having an ear portion and a shaft portion is upset and forged in the axial direction of the shaft portion, so that the forging convex portion can be formed integrally with the shaft portion. Can be done.

Moreover, according to the forging die of the present invention, the above-described method for forging a convex portion can be carried out.

[Brief explanation of the drawing]

Figures 1 to 14 show an embodiment of the present invention, in which Figure 1 is a side view of a round bar, Figure 2 is a plan view of a raw material, Figure 3 is a side view of a raw material, and Figure 4 is a side view of a raw material. The figure is a plan view of the steering yoke blank before forming the forged convex part, FIG. 5 is a side view of the steering yoke blank before forming the forged convex part, and FIG.
The figure is a plan view of the steering yoke blank after forming the forged convex portion, and FIG. 7 is a side view of the steering yoke blank after the forged convex portion is formed. Figure 8 is a cross-sectional view of the forging die, Figure 9 is a cross-sectional view of the main parts with the punch die driven into the die cavity, Figure 10 is a side view of the punch die attached to the punch holder, and Figure 11 is a side view of the punch die attached to the punch holder. The figure is a side view of the punch die attached to the punch holder as seen from different directions, Figure 12 is a perspective view of the punch die attached to the die die, and Figure 13 is the punch die attached to the punch holder. FIG. FIG. 14 is a cross-sectional view of the main part in a state where a punch die is driven into the die to form a forged convex portion. Figures 15 to 17 show a conventional steering yoke after machining, Figure 15 is a side view of the machined steering yoke, Figure 16 is a plan view of the machined state, and Figure 17 is a side view of the machined steering yoke. The figure is a side view of the same. In the figure, 1 is the shaft part, 2 is the forged convex part, 3 is the ear part, 8 is the base,
9 is a knockout type, 11 is a movable type, 31 is a punch type,
32 a 1. lt is the first punch type, 33a is the second punch type, 40 is the second constraint type surface, 41 is the third constraint type surface, 4
3 is a mold surface for forming a convex portion, 44 is a space, and 47 is a biasing member. Patent applicant: Aichi Steel Co., Ltd. Agent: Hiroshi Okawa, patent attorney

Claims (3)

[Claims] (1) A metal material having a U-shaped or V-shaped ear portion and a shaft portion that is connected to an intermediate portion of the ear portion and runs in the same direction as the center line of the ear portion; a restraining type surface that corresponds to a surface forming the ear of the shape material and restrains the ear, and a restraining surface that corresponds to a surface that forms the shaft of the blank material and restrains the shaft; and the shaft. a forging die having a space for forming a convex part provided between the outer surface and a part of the outer surface in the axial direction of the forging die; while restraining with the restraining mold surface of the forging mold, and restraining a portion of the surface forming the shaft part other than the surface corresponding to the space part with the restraining mold surface of the forging mold, while suppressing deformation of the ear part. Forging in which the shaft portion is upset in the axial direction thereof, a part of the flesh portion of the shaft portion flows into the space for forming a convex portion, and the shaft portion bulges in a direction intersecting the axis. A method for forging a convex portion of a forged product having a U-shaped or V-shaped ear portion, characterized in that the convex portion is formed integrally with the shaft portion. (2) The method for forging a convex portion of a forged product having a U-shaped or V-shaped ear portion according to claim 1, wherein the blank material is a yoke blank material. (3) A forging die for pressing a metal material having a U-shaped or V-shaped ear and a shaft connected to the middle of the ear and extending in the same direction as the center line of the ear. and a base having a knockout hole, and a shaft end surface that is inserted into the knockout hole of the base and has a shape corresponding to a shaft end surface located on the opposite side of the ear of the shaft of the formed material. a knockout mold having a first restraining mold surface for restraining; a punch mold having a punch mold surface having a shape corresponding to the inner facing surface of the ear and restraining the inner facing surface; and the ear of the blank material. a second restraining type surface having a shape corresponding to the rear surface of the material and restraining the rear surface; and a second restraining type surface having a shape corresponding to the outer surface extending along the axial direction of the shaft portion of the formed material and the outer surface. A movable mold having a third restraining mold surface that restrains the mold, and a mold surface for forming a convex portion that partitions a space for forming a convex portion between a part of the outer surface of the shaft portion of the molded material. A mold, and a biasing member interposed between the movable mold and the base and biasing the movable mold toward the punch mold, the punch mold resisting the biasing force of the biasing member. The punching die face of the punch die and the second restraining die face of the movable die restrain the ear portion of the blank material while swiveling the shaft portion in the axial direction of the shaft portion. A forging die characterized by: