JPH0790323B2 - Press forming method for drum-shaped tubular parts - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tubular part having a drum shape by forging.

[0002]

2. Description of the Related Art A forging machine for producing bolts, nuts, and other parts usually uses a material supplied from the side of a machine base to rough a material at a forging station equipped with a die and a punch facing each other. Since the above products are continuously manufactured by precisely forging in stages, there is an advantage that high quality products can be manufactured efficiently.

[0003]

By the way, for example, when mounting a vibration source on a fixed frame or the like, as shown in FIG.
As shown in FIG. 5, the tubular part X and the sleeve B located inside the tubular part X are connected by baking the vulcanized rubber C to fix the tubular part X to the fixed frame, and the sleeve B
There is known a shock absorbing device A that shock-transmits vibration to a fixed frame by the deformation of the vulcanized rubber C by connecting a vibration source to the cylindrical frame. In some cases, both ends may have a trumpet shape in which the both ends are flared. Due to the outer shape of the hourglass-shaped tubular component X, it is difficult to remove the component X from the die after molding. Therefore, the component X cannot be molded by the above-described pressing, and therefore depends on the material of the material. A method of punching the material with a vertical press machine and then forming it into an hourglass shape by the same press, or producing a long cylinder, and then cutting this into a ring shape and then forming it into an hourglass shape with a press. Will be taken.

However, such a method has a problem that productivity is poor and it is difficult to manufacture a cylindrical part having a highly accurate size, and a post-process such as deburring is required.

Therefore, an object of the present invention is to provide a method capable of manufacturing a drum-shaped tubular component with high precision by press forming with high productivity.

[0006]

[Means for Solving the Problems] That is, claim 1 of the present invention.
The invention described in (hereinafter referred to as the first invention) sequentially supplies a solid short cylindrical material to a plurality of forging stations each having a die and a punch, and both ends thereof are expanded into a trumpet shape. A method for forging an opened hourglass-shaped tubular part, comprising a first forging forming step of forming the material into a cup shape by recessing one end face in the die, and the cup forming step in the die as well. A second forging forming step of punching out the bottom of the material to form a tubular shape, and expanding one end side of the punch side into a trumpet shape, and a tube ejected from the die by the completion of the second forging forming step. The blank material is inverted so that the other end that is not expanded faces the punch side, and is transferred to the front surface of the die, which is the flat surface of the next forging station, and the cylindrical material is attached to the tip of the die by the punch. Contact the other end side Is expanded in a trumpet shape by the punch,
It is characterized by comprising a third forging forming step for forming a drum-shaped tubular part.

The invention according to claim 2 (hereinafter referred to as the second
(Referred to as the invention) sequentially supplies a solid short cylindrical material to a plurality of forging stations each having a die and a punch, and forms a drum-shaped tubular part whose both ends are expanded into a trumpet shape. A method of forging, which comprises a first forging forming step of forming the material into a cup shape by recessing one end surface in the die, and a bottom portion of the cup-shaped material is punched into a cylindrical shape in the die as well. A second forging forming step of forming and expanding one end side of the punch side into a trumpet shape by a punch, and a forging station in which a tip of the die is provided with a tapered protrusion toward the punch side, A third part for forming a drum-shaped tubular part by expanding the other end side into a trumpet shape by punching into the other end side of the tubular material, which is not expanded, so that the other end side is expanded. Forging forming Characterized in that it consists of a degree.

[0008]

According to the first aspect of the present invention, the material punched out from the die after one end side of the second forging forming process is expanded is inverted to the forging station for performing the next third forging forming process. The other end side which has been transferred and is not expanded by the reversal is directed to the punch side, and the other end side is expanded by the punch on the front surface of the die that is blindly closed in that state. In this way, by using the reverse transfer of the material and the molding of the other end side of the material outside the die together, the hourglass-shaped tubular component can be manufactured by the press machine.

Further, according to the second aspect of the present invention, the material punched out from the die after one end side of the die is expanded in the second forging forming step is applied to the die side in the forging station for performing the next third forging forming step. The other end side which faces is struck by a punch so as to fit into the protruding part which is protruded at the tip of the die, whereby the other end side is expanded. By using a die in which the protrusion is formed at the tip of the die as described above, the hourglass-shaped tubular component can be manufactured by the press machine.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the shape change in the forming process of the hourglass-shaped tubular part X by the forging machine. One end face of the solid short cylindrical raw material x1 is formed at the first forging station, and then, The other end surface of the formed material x2 is formed in a second forging station, the formed material x3 is carried into a third forging station and formed into a cup shape, and the cup-shaped material x4 is formed. In the fourth forging station, while forming into a tubular shape, one end side thereof is expanded into a trumpet shape, then the other end side of the tubular material x5 is also expanded into a trumpet shape, and the drum obtained by this is further expanded. The corners of both ends of the shape material x6 are chamfered at the sixth forging station, whereby a drum-shaped tubular part X having a chamfered part a is formed.

The forming process will be described with reference to the first embodiment shown in FIGS. 2 and 3. First, the die 2 provided on the front surface of the machine base 1 and the punch 3 arranged opposite to the die 2 are used. The forging station Z1 is configured, the second forging station Z2 is configured by the die 4 and the punch 5, the third forging station Z3 is configured by the die 6 and the punch 7, and the fourth is formed by the die 8 and the punch 9.
Of the forging station Z4, the die 10 and the punch 11 constitute a fifth forging station Z5, and the die 12 and the punch 13 constitute a sixth forging station Z6. The forging stations Z1 to Z6 up to the sixth are arranged in a horizontal row at a predetermined interval.

In the first forging station Z1, the material x1 cut into a predetermined length as shown in FIG. 2 is chucked by the chuck claws 14 and 14 and carried into the front surface of the die 2. Then, the punch 3 drives the material x1 into the die 2 as shown in FIG.
One end surface facing the side is molded in the die, and thereby the rough cut surface of the material x1 is precisely molded.

Next, the material x2 after molding is extruded from the die 2 by the knockout pin 15a, which is chucked by the chuck claws 14 and 14 and is shown in front of the die 4 in the second forging station Z2 as shown in FIG. Is transferred as. In that case, the material x2 is 180
^{It is} reversed so that the other end surface faces the die 4 side. Therefore, when the punch 5 is hit, the other end surface which has been roughened by cutting the material is precisely formed in the die as shown in FIG.

Next, after the above-mentioned molding, the knockout pin 15
The material x3 projected from the die 4 by b is chucked by the chuck claws 14 and transferred to the front surface of the die 6 of the third forging station Z3 as shown in FIG.
It is driven into the die 6 by the punch 7. This die 6 is shaped to mold the material x3 into a cup shape,
As a result of this driving, as shown in FIG. 3, a cup-shaped material x4
Is molded.

The cup-shaped material x4 projected from the die 6 by the above-mentioned knockout pin 15c after molding is shown in FIG.
As shown in FIG. 4, the chuck jaws 14 and 14 transfer the same to the front surface of the die 8 of the fourth forging station Z4, and the punch 9 drives the punch 8 into the die 8. In that case, the die 8 and the punch 9 in this fourth forging station Z4
Is one in which the bottom portion 16 (see FIG. 1) of the cup-shaped material x4 is punched out to form the material into a tubular shape and one end side facing the punch 9 side is expanded into a trumpet shape. Therefore, the shape of the tip end side of the die 8 (the front side of the machine base 1) is opened in a trumpet shape, and the passage 1 for discharging the bottom portion 16 is formed in the inner back portion.
7 are in communication. On the other hand, the tip 9a of the punch 9 is formed in order to expand one end side of the material x4 into a trumpet shape.
4 has a tapered shape like a reverse trumpet that can rush into the inside of the container 4, and is relatively long so as to push the punched bottom portion 16 into the discharge passage 17.

That is, in the fourth forging station Z4, the punch tip 9a is pushed into the cup-shaped material x4 by hitting the punch 9, and the bottom 16 is punched out, and at the same time, one end of the material x4 on the die tip side is pushed. It is spread like a trumpet over half the length of the material.

After the above-mentioned forming, the tubular material x5 projected from the die 8 by the knockout pin 15d is transferred to the front surface of the die 10 of the fifth forging station Z5 by the chuck claws 14,14. In that case, the transfer is performed by reversing the tubular material x5 as shown in FIG. 4, and by this, one end side formed into a trumpet shape is controlled to face the die 10 side. Therefore, as shown in FIG. 2, the raw material x5 is carried in in a posture in which one end side which is expanded is directed to the die 10 side and the other end side which is not expanded is directed to the punch 11 side. Further, the die 10 in the fifth forging station Z5 is a flat surface that is closed blindly so as to be substantially flush with the front surface of the machine base 1, and is not shaped to drive the material X5 into the inside. Together with the tip 11a of the punch 11
Is a reverse trumpet taper like the punch 9 in the fourth forging station Z4. However, punch 9
Since the bottom 16 is not punched out as described above, it is shorter than the tip 9a of the punch 9.

In the fifth forging station Z5, when the punch 11 is hit, the punch tip 11a plunges into the material x5 from the other end side which is not expanded as shown in FIG. The expanded one end of the material x5 hits the die 10, and in this state, the other end side is expanded into a trumpet shape. As a result, a drum-shaped material x6 whose both ends are expanded into a trumpet shape is obtained.

Subsequently, the material x6 is chuck claws 14,14.
Is transferred to the sixth forging station Z6. In this sixth forging station Z6, the corners of both ends of the material x6 are chamfered, and as shown in FIG. A projection 12a having a tapered shape for positioning is formed inside, and the projection 12 is formed.
A stepped portion 18 for chamfering is formed around the base portion of a. Further, in the punch 13, a rod 19 having a tapered tip portion 19a for positioning is inserted therein, and a step portion 20 for chamfering is formed at a portion surrounding the rod 19 at the tip of the punch. It

At the sixth forging station Z6, the rod 19 and the punch 13 move forward to move the rod tip 19a.
While plunging inside the material x6, die 12 the material x6
And the protrusion 12a in the die 12 is thrust into the material x6 from the opposite side by this driving to position the material x6, and the corners of both ends of the material x6 form the die 12. The chamfers are chamfered by the chamfered step portions 18 and 20, respectively. After the chamfering, the rod 19 and the punch 13 retreat,
The knockout pin 15e projects the tubular part X and the molding is completed.

In this way, in the fourth forging station Z4, the material is first formed into a tubular shape and the material x5 is formed.
Open one end side of the
The punch 1 is transferred to the forging station Z5, and at the fifth forging station Z5, the material x5 is punched on the front surface of the die 10 having a flat tip end to form the punch 1.
Since the other end side of the material x5 is expanded by 1, the hourglass-shaped tubular part X can be manufactured by press forming. Therefore, the hourglass-shaped tubular part X can be efficiently manufactured, and
It is possible to improve the dimensional accuracy of the parts and obtain a good quality product. Further, since burr does not occur, a post-process such as deburring is unnecessary.

Although the sixth forging station Z6 for chamfering is provided in the above embodiment, when the chamfering is not necessary, the forming is finished up to the fifth forging station Z5 to complete the blank x6. It can be a shaped part.

FIG. 6 shows a second embodiment of the present invention.
4th forging station Z4 to 5th forging station Z
The material x5 is transferred to No. 5 without reversing the material x5, and the material x5 is transferred at the fifth forging station Z5.
The expansion molding is applied to the other end side of the.

That is, the die 100 in the fifth forging station Z5 is formed with a taper-shaped protruding portion 100a having a reverse trumpet shape in a state of protruding from the front surface of the machine base 1, and a punch 111 in FIG. Unlike the punch 11 of the first embodiment, the tip has a flat shape.

Then, by punching the material x5 carried in from the fourth forging station Z4 without reversing, the projecting portion 100a is driven into the other end side of the material facing the die 100 side. The other end side is expanded to form a drum shape. The other press forming steps are the same as in the first embodiment.

Also in this case, it is possible to manufacture the hourglass-shaped tubular part X by press forming as in the first embodiment.

In FIG. 6, the protruding portion 100a is attached to the machine base 1
6th forging station Z
As in the case of 6, the structure may be provided inside the die. Further, although the hourglass-shaped tubular component X is used as a shock absorber in the above example, the present invention is not limited to this cushioning device, and is widely applied to those having the hourglass-shaped tubular part as a part. Of course.

[0029]

As is apparent from the above description, according to the present invention, the material punched out from the die after the one end side of the second forging forming step is expanded and then the material is punched out in the following third forging forming step. Then, the other end side, which has not been expanded yet, is directed to the punch side by the reversal, and the other end side is expanded by the punch on the front surface of the die. In this way, by using the reverse transfer of the material and the molding of the other end of the material outside the die together, it is possible to manufacture a drum-shaped tubular part by a press machine, and it is possible to efficiently and accurately produce a high-quality tubular part. Can be manufactured.

Further, according to the present invention, the material punched out from the die after one end side of the die is expanded in the second forging forming step is transferred to the die side in the forging station for performing the next third forging forming step. The other end side which faces is struck by a punch so as to fit into the protruding part which is protruded at the tip of the die, whereby the other end side is expanded. By using a die in which the protrusion is formed at the tip of the die as described above, the hourglass-shaped tubular component can be manufactured by the press machine.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view showing a shape change of a drum-shaped tubular component according to the present invention in a press forming sequence.

FIG. 2 is an explanatory diagram before punching in the press molding machine.

FIG. 3 is an explanatory diagram after punching in a press molding machine.

FIG. 4 is a diagram illustrating reverse transfer of materials.

FIG. 5 is an explanatory diagram of a chamfering process of a material.

FIG. 6 is an explanatory diagram of a second embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a usage example of the hourglass-shaped tubular component.

[Explanation of symbols]

 1 Machine stand 2,4,6,8 Die 3,5,7,9 Punch 10,12 Die 11,13 Punch 100 Die 100a Protruding part 111 Punch X Hourglass tubular part x1 to x6 Material Z1 to Z6 Pressing station

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 54-99767 (JP, A) JP 3-230842 (JP, A) JP 3-254328 (JP, A) Actual flat 3- 68942 (JP, U)

Claims (2)

[Claims] 1. A solid short cylindrical material is sequentially supplied to a plurality of forging stations each having a die and a punch to forge a drum-shaped tubular part whose both ends are flared. A method of forming a cup-shaped material by denting one end face in a die.
And the second forging forming step of punching out the bottom portion of the cup-shaped material into a cylindrical shape in the die and expanding one end side of the punch side into a trumpet shape, and the second The cylindrical material released from the die after the completion of the forging process is inverted so that the other end that is not expanded faces the punch side and transferred to the front surface of the die, which is the flat surface of the next forging station. And a third material is pressed against the tip of the die by the punch and the other end side is expanded into the trumpet shape by the punch to form a drum-shaped tubular part. A method for forging a drum-shaped tubular part featuring. 2. A solid short cylindrical material is sequentially supplied to a plurality of forging stations each having a die and a punch to forge a drum-shaped tubular part whose both ends are flared. A method of forming a cup-shaped material by denting one end face in a die.
Secondly, in the die forming process, the bottom portion of the cup-shaped material is punched into a cylindrical shape in the die, and one end of the punch side is expanded into a trumpet shape by the punch.
In the forging process, and in the forging station where the tip of the die is provided with a tapered protrusion toward the punch side, the protrusion is projected into the other end side of the cylindrical material which is not expanded. A forging-molding method for a drum-shaped tubular part, comprising a third forging-molding step for forming a drum-shaped tubular part by expanding the other end side into a trumpet shape by punching into the .