JPH0566222B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a helical forging device for forging a helical portion on the outer or inner circumferential surface of a workpiece.

[Conventional technology]

Conventionally, for example, when forming a helical portion on the outer peripheral surface of a workpiece, the workpiece was press-fitted into a die having helical teeth on the inner peripheral surface while pressing the workpiece with a punch. That is, by pressing the punch against the workpiece, the workpiece is rotated along the helical teeth of the die to form a helical groove on the outer peripheral surface of the workpiece.

[Problem to be solved by the invention]

In the conventional technology, the workpiece may not rotate as desired due to frictional resistance generated between the workpiece and the die, and in that case, the helical tooth has the same helix angle as the helical tooth of the die. No helical part is formed.

Further, since the punch presses the workpiece, a punch holder or the like holding the punch receives a reaction force from the punch, and there is a risk that the punch holder may be damaged by the reaction force.

Accordingly, one object of the present invention is to provide a helical forging device that can accurately control the twist angle of the helical portion to be formed, and another object of the present invention is to provide a helical forging device that is capable of forming a helical portion with an accurate twist angle. The objective is to provide a helical forging device that can withstand

[Means to solve the problem]

In order to achieve the above object, the helical forging device of the present invention is a helical forging device that forges a helical part on the outer peripheral surface or inner peripheral surface of a workpiece using helical teeth of a die; a rotatable punch having a rotatable punch; a ring body with an inner circumferential helical part that is screwed into the punch so that it can move forward and backward and cannot be detached; the ring body with an inner circumference helical part locks in a predetermined position, and and a locking mechanism 24 that rotates the punch and the workpiece integrally along the inner and outer circumferential helical portions when the ring body is locked, and also presses the workpiece. A punch that rotates the workpiece relative to the die is held by a punch holder, and the holder is rotatably held by a holder and receives a reaction force from the punch. , and a holder pressure receiving part facing the pressure receiving part, and oil is interposed in a sealed or pressurized state between the holding body pressure receiving part and the pressure receiving part.

[Effect]

When the punch approaches the die and the inner helical grooved ring body is in a predetermined position, the ring body is locked in the locking mechanism, and in the locked state, the punch and the workpiece are integrated and the inner and outer helical grooves It is rotated by a helical groove, and a helical portion is formed in the workpiece by the helical teeth of the die.

Even when the punch is separated from the die and the locking mechanism of the ring body is released, the ring body does not separate from the punch, so the inner helical portion of the ring body always Since it is screwed into the helical part, the rotation of the punch and the rotation of the workpiece will not be inconsistent.

Further, since oil is interposed between the holder pressure receiving section and the punch holder pressure receiving section, the pressure receiving area that receives the reaction force from the punch becomes large, and the reaction force can be sufficiently withstood.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 shows a helical forging device according to the present invention, which forges a helical portion 4 on the outer circumferential surface 3 of a helical tooth 2 of a die 1, and is a cold forging device.

This device is equipped with an upper mold 5 and a lower mold 6, the upper mold 5 being able to move up and down, and the upper mold 5 being able to approach and move away from the lower mold 6. A die 1 is attached to the lower die 6, and a punch 7 for pressing the workpiece W into the die 1 is attached to the upper die 5.

That is, the lower die 6 is provided with a die holding holder 9 having a hole 8, and the die 1 is fitted into the upper end of the hole 8. A die retaining body 11 is detachably attached to the holder 9 via a fixing member 10 such as a bolt.
is installed. Moreover, this retaining body 11 is
Ring body 12 placed on the upper end surface of holder 9
and a cylindrical body 13 that is fitted into the ring body 12 so that it cannot come out.

Note that a knockout pin 14 is inserted into the hole 8 of the holder 9 so as to be vertically movable.

Further, the upper die 5 is provided with a holder 16 in which a punch holder 15 is rotatably held, and the punch 7 is held in the punch holder 15.

Thus, the punch 7 has an outer circumferential helical portion 17 on the outer circumferential surface with a predetermined twist angle (that is, the same twist angle as the helical teeth 2 of the die 1).
is formed, and a retaining ring 18 is fitted to the tip. Further, the punch holder 15 is rotatably held in a holder 16 via bearings 19 and 20, and is attached to the lower end of the holder 15 with a fixing device 21 such as a cap nut to the upper end of the punch 7. section is installed. In other words, when the punch holder 15 rotates, the punch 7 rotates together with the punch holder 15.

As shown in FIG. 3, a ring body 23 with an inner circumferential helical portion 22 is fitted onto the outside of the punch 7 so as to be able to be screwed forward and backward. Moreover, this ring body 23 is
The above-mentioned retaining ring 18 prevents the punch from detaching from the punch 7.

Furthermore, the ring body 23 is locked in a locking mechanism 24 at a predetermined position and is rendered unrotatable. Here, the locking mechanism 24 includes a latch portion 25 formed on the upper end surface of the cylindrical body 13 of the retaining body 11 and a latch 26 formed on the lower end surface of the ring body 23.
, the upper mold 5 descends, and the ratchet 2
When 5 and 26 engage with each other, rotation of the ring body 23 is made impossible. A resilient member 27 made of a coil spring is interposed between the ring body 23 and the fixing member 21 to constantly press the ring body 23 downward.

Therefore, when the upper die 5 rises from the state shown in FIG. 1, the punch 7 rises while stopping its rotation, and the ring body 23 rotates along the helical parts 22, 17. The ring body 23 side rotates due to the large weight of the punch holder 15 and the punch 7. As shown in FIG. 2, when the ring body 23 comes off the cylindrical body 13 of the retaining body 11, the ring body 23 is pressed by the resilient member 27 and is positioned at the lower end of the punch 7. However, the retaining ring 18 prevents it from coming off the punch 7. In other words, the inner helical portion 22 of the ring body 23 and the outer helical portion 17 of the punch 7 are always screwed together. Note that, instead of the retaining ring 18, a ring-shaped protrusion may be formed on the punch 7.

Therefore, the holder 16 that holds the punch holding part 15 is a block body 29 that is attached to the upper die 5 so as to surround the recess 28 provided in the upper die 5.
It is equipped with That is, the holding body 15 has a disk portion 15
a, an upper cylindrical part 15b erected on the upper end surface of the disc part 15a, a conical part 15c perpendicularly provided on the lower end surface of the disc part 15a, and a lower cylindrical part 15c perpendicularly provided on the lower end surface of the conical part 15c. The cylindrical portion 15d and the upper cylindrical portion 15b are fitted into the inner part 30 of the recess 28.

Then, the recess 28 and the disc body 15 of the holding body 15
A gap 31 is formed at a predetermined interval between the upper end surface of the upper cylindrical body 15b and the upper end surface of the upper cylindrical body 15b, and oil 32 is interposed in the gap 31. Further, the above-mentioned bearing 20
is interposed. The bearing 19 is interposed between the inner peripheral surface 29a of the block body 29 and the outer peripheral surface 34 of the lower cylindrical portion 15d.

Therefore, the oil 32 is transmitted to the pressure receiving portion 35 of the holder 16 that receives the reaction force from the punch 7, and to the pressure receiving portion 35 of the holder 16, which receives the reaction force from the punch 7.
This means that it is interposed between the holding body 15 and the pressure receiving part 36 facing the holding body 15 . Here, the pressure receiving section 36 is formed by the upper end surface of the disk section 15a, the outer peripheral surface 33 of the upper cylindrical section 15b, and the upper end surface of the upper cylindrical section 15b. It is formed with the bottoms of the recesses 28 facing each other. Further, a communication path 37 is formed in this gap 31 and is connected to the outside.
Oil 32 is injected into. And the holding body 15
An oil ring 38 is fitted onto the disk portion 15a. Here, the oil ring 38 is the fourth
As shown in the figure, it is provided with a ring 39 having a substantially U-shaped cross section.

The oil 32 is sealed or pressurized within the gap 31.
As shown in the figure, a preload is applied to improve the adhesion between the inner and outer circumferential walls 40, 41 of the ring 39. 4
2 is a back up spring. Reference numeral 47 denotes a connector provided in the communication path 37, to which an oil pipe (not shown) is connected.

Therefore, in order to forge the helical portion 4 on the outer circumferential surface 3 of the workpiece W using the helical forging device configured as described above, first, as shown in FIG. The work W is not inserted into the cylindrical body 13, and the workpiece W is not inserted into the cylindrical body 13.
After the upper die 5 is lowered, the punch 7 is lowered as shown by the arrow, and the ring body 23 is locked to the cylindrical body 13.
Then, the punch 7 is further lowered from this locked state, and the punch 7 is moved between the inner and outer helical parts 22,
17, the workpiece W is inserted into the cylindrical body 13 while being rotated along
is brought into pressure contact with the lower end surface 44 of the punch 7, and the workpiece W is lowered and press-fitted into the die 1.
A helical portion 4 is formed on the outer circumferential surface 3 of.

At this time, the torsion angle of the inner and outer peripheral helical parts 22 and 17 and the torsion angle of the helical teeth 2 of the die 1 are made the same, and the punch 7 is forcibly rotated. When forming, the workpiece W is rotated as desired,
A helical portion 4 having the same helix angle as the helix angle of the helical teeth 2 of the die 1 is formed.

Therefore, while the helical portion 4 is being formed, the pressure receiving portion 35 of the holder 16 receives the reaction force from the punch 7, but there is a gap between the pressure receiving portion 35 of the holder 16 and the pressure receiving portion 36 of the punch holder 15. Since the oil 32 is interposed, the pressure-receiving area that receives the reaction force from the punch 7 becomes large, and the reaction force can be sufficiently withstood. Further, this oil 32 has the advantage that the bearing 20 is lubricated. Incidentally, the lower end surface 44 of the punch 7 and the upper end surface 45 of the workpiece W are provided with concave and convex portions that fit into each other to prevent displacement of the punch 7 and the workpiece W while the helical portion 4 is being formed.

Next, FIG. 5 shows another embodiment, in which case,
The helical portion 4 is forged on the inner circumferential surface 45 of the workpiece W. That is, the die 1 has a rod-shaped body 46 having helical teeth 2 on the outer circumferential surface, and when the punch 7 is lowered, the cylindrical workpiece W rotates and the rod-shaped body 46 is rotated.
5, and the helical portion 2 is formed on the inner circumferential surface 45 of the work W.

Moreover, FIG. 6 shows yet another embodiment, and in this case as well, the helical portion 4 is forged on the inner peripheral surface 45 of the workpiece W, but in this case the workpiece W does not rotate. . That is, the rod-shaped body 47 having the helical teeth 2 on the outer periphery is inserted into the workpiece W while rotating as the punch 7 descends, and the helical portion 4 is formed on the inner peripheral surface 45 of the workpiece W.

Note that the present invention is not limited to the above-mentioned embodiments, and the design may be changed without departing from the gist of the present invention.
For example, the twist angle of the helical portion 4 to be formed can be any angle other than the illustrated example.
Further, in the embodiment, the lower mold 6 is fixed and the upper mold 5 is moved up and down, but it is also possible to fix the upper mold and move the lower mold 6 up and down. As a product, a helical gear having the helical portion 4 or the like can be manufactured, but of course a spline shaft or the like can also be manufactured.

〔Effect of the invention〕

Since the present invention is configured as described above,
This produces the following effects.

In the helical forging device according to claim 1, the workpiece W is rotated along the helical teeth 2 of the die 1 by forced rotation along the inner and outer helical portions 22, 17 of the punch 7, and the workpiece W is formed. The twist angle of the helical part 4 is the helical tooth 2 of the die 1.
The helical portion 4 can be reliably formed even if the helical portion 4 has a large twist angle.

Furthermore, since the ring body 23 is always held in a state where it is externally fitted onto the punch 7, the inner and outer peripheral helical parts 22 and 17 are always in a screwed state, and the rotation of the punch 7 and the rotation of the work W There is no mismatch between the two, and it is possible to always manufacture a workpiece W having a constant helical portion 4.

In the helical forging device according to claim 2, the pressure receiving part 3 receives the reaction force from the punch 7 during forging.
5 and 36 can sufficiently withstand the reaction force, and can withstand use over a long period of time, resulting in excellent durability.

[Brief explanation of the drawing]

Fig. 1 is a sectional front view of the main part showing an embodiment of the present invention, Fig. 2 is a sectional view of the main part, Fig. 3 is a sectional view taken along the line X--X in Fig. 2, and Fig. 4 is an enlarged sectional view of the main part. 5 and 6 are sectional views of main parts of other embodiments, respectively. 1...Die, 2...Helical tooth, 3...Outer peripheral surface, 4...Helical part, 7...Punch, 15...
Punch holder, 16...Holder, 17...Outer helical part, 22...Inner helical part, 23...Ring body, 24...Locking mechanism, 32...Oil, 3
5, 36...Pressure receiving part, 45...Inner peripheral surface, W...Work.

Claims (1)

[Claims] 1. A helical forging device for forging a helical portion 4 on the outer circumferential surface 3 or inner circumferential surface 45 of a workpiece W using the helical teeth 2 of a die 1, which forges an outer circumferential helical portion 17 with a predetermined helix angle. a rotatable punch 7 having a rotatable punch 7; a ring body 23 with an inner circumferential helical portion 22 fitted externally to the punch 7 so as to be able to be screwed back and forth but not detachable; and the ring body 23 with an inner circumferential helical portion 22 locked in a predetermined position. and a locking mechanism 24 that rotates the punch 7 and the workpiece W integrally along the inner and outer circumferential helical parts 22 and 17 while the ring body 23 is locked. A helical forging device characterized by: 2 A helical forging device that forges a helical portion 4 on the outer circumferential surface 3 or inner circumferential surface 45 of a workpiece W using the helical teeth 2 of a die 1, which presses the workpiece W and presses the workpiece W against the die 1. The punch 7 to be rotated is held by the punch holder 15.
At the same time, the holding body 15 is held in the holder 1.
Oil 32 is sealed between a pressure receiving part 35 of the holder 16 which is rotatably held at 6 and receives a reaction force from the punch 7, and a pressure receiving part 36 of the holder 15 which faces the pressure receiving part 35. Or a helical forging device characterized by intervening in a pressurized state.