JP2698335B2 - Helical gear manufacturing method and helical gear dice device - 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 manufacturing a helical gear by forging and forging, and a helical gear die apparatus.

[0002]

2. Description of the Related Art It has been proposed to manufacture a helical gear by forging and forging. This is performed by driving a blank having a diameter equal to or slightly larger than the tooth tip diameter of the completed helical gear into a die.

[0003] Since a torsion ridge corresponding to the teeth of the helical gear is formed in the die hole of the die, when the blank driven into the die hole is protruded with a pin, the blank corresponds to the torsion ridge. It is protruded while rotating. Therefore, if the protruding pin is simply advanced, strong friction occurs on the contact surface between the blank and the protruding pin, and the contact surface seizes,
The blank cannot be pushed out smoothly.

Therefore, the applicant previously set up a torsion groove corresponding to the torsion protrusion (24) of the mold hole on the outer periphery of the protrusion pin, and engaged the fixing pin with the torsion groove to advance the protrusion pin. It has been proposed that the projecting pin be forcibly rotated in accordance with the above, so that the blank is ejected smoothly without friction between the blank and the projecting pin. When adopting a structure in which the protruding pin is forcibly rotated, it takes time to process the groove on the protruding pin, mounting the fixed pin in the die, etc. It is inevitable that the strength of the protruding pin and the die is reduced by the processing. The present invention discloses a helical gear manufacturing method and a helical gear dice device that solve the above problems.

[0005]

According to the present invention, there is provided a helical gear die apparatus comprising: a die (3) having a torsion ridge (24) corresponding to a tooth surface of a helical gear on an inner surface of a die hole; and a punch for driving a blank into the die hole. A die device comprising a combination of (6) and a protruding pin (4) for protruding a blank driven into the die, wherein the protruding pin (4) is configured by arranging a plurality of pin members in a straight line, At the center of the end surface of one of the pin members, there is a projection (45) which is a point contact at the center of the end surface of the adjacent pin member or blank.

The method of manufacturing a helical gear according to the present invention comprises the steps of: driving a blank into the die hole of a die (3) having a twisted ridge (24) corresponding to the tooth surface of the helical gear on the inner surface of the die hole; A torsion groove is formed by the torsion ridge (24),
The blank is protruded from the mold hole by (4), and the protrusions (41) and (41a) formed on the protruding pin (4) come into contact with the center of the end face of the blank so that the blank protrudes.
When a plurality of pin members are combined on a straight line, and a protruding pin having a protrusion toward the pin member adjacent to the center of the end face of at least one pin member is used, the protrusion comes into contact with the mating pin member.

[0007]

When the protruding pin (4) advances and ejects the blank, if the blank and the protruding pin are in contact with the center of the blank end face, the friction between the blank and the protruding pin is small. Does not seize between the blank and the projecting pin, the blank is projected while rotating smoothly along the torsional ridge.

In the case where a plurality of pin members are combined in a straight line and a protruding pin having a protrusion toward the pin member adjacent to the center of the end surface of at least one pin member is used, the protrusion is located at the center of the end surface of the mating pin member. You get a hit. The friction between the pin members adjacent to each other at a point is small, and if a rotational force acts on the pin member on the blank side, the pin member rotates easily.
Therefore, when the blank is protruded, when the blank rotates along the torsion ridge, the pin member that is in press contact with the blank also rotates, that is, the blank can be smoothly protruded from the mold hole. As in the past, complicated processing and configuration for forcibly rotating the protruding pin are not required, and the strength of the die and the protruding pin due to the processing can be prevented from being reduced, and there is little trouble during operation. .

[0009]

1 and 2 show an example of a manufacturing process of a helical gear according to the present invention, in which a shearing process and first to third forging / forging processes are performed. Each of the forging and forging processes is performed by punching blanks into dies set in a row in a die block of a multistage horizontal transfer press called a part former. The shearing step includes a shearing device provided before the first forging / forging step.
(Not shown). 1 and 2,
The upper side is the punch side, and the lower side is the die side. In the shearing process, heat treatment such as annealing, and bonding treatment on the surface (lubrication treatment)
Is cut to a predetermined length to form a blank B1.

In the first forging / forging step, a tapered surface b1 is formed on the outer peripheral edge of the die on the die side (No. 1 in FIG. 1). In the second forging / forging step, the blank B2 with the tapered surface b1 is reversed and pressed to form a tapered surface b2 also on the outer peripheral edge on the opposite side (No. 2 in FIG. 1). In the third forging / forging step, a tooth surface b3 is preformed on the blank (FIG. 2).
No3). Hereinafter, the third forging / forging process will be described in detail together with the configuration of the die device.

[0011]

[Tooth surface pre-forging / forging process] The die device (1) for the forging / forging process shown in FIG. 3 is a die (3) which is housed in a die block and located at the front, a spacer (5) located at the rear, and a die. (3) A protruding pin (4) penetrating the spacer (5) in a slidable manner and a punch for punching a blank into a die.
(6). The die (3) is provided with a nib receiving hole (12) on the punch (6) side of the axis of the die case (31) and a pin slide hole (13) which protrudes to the back side continuously to the hole to open the nib. The nib (2) is press-fitted or shrink-fitted in the hole (12).

A die hole (23) is formed through the axis of the nib (2), and the blank (B3) having been subjected to the second forging / forging process is tightly closed on the punch (6) side of the die hole (23). A perfect circular guide hole (2
1) The back side is a mold part (22) in which torsional ridges (24) corresponding to the helical gear to be formed project at equal pitches in the circumferential direction. On the inner surface of the mold hole (23), a layer of TiC, TiCN or TiN having a thickness of 5 to 10 μm is formed by a chemical vapor deposition method or a physical vapor deposition method. TiC, TiCN or TiN has excellent seizure resistance and abrasion resistance, and can extend the life of the nib (2) that repeatedly comes into pressure contact with the blank.

The front end of each torsion ridge (24) has a slope (25) so that it can easily bite into the blank, and the slope is centered on the axis.
(25) The angle α formed by (25) is 90 to 120 °. The angle α formed by the slopes (25) and (25) at the front end of each of the torsion ridges (24) has a great effect on the biting of the blank and the precision of the tooth surface to be formed. However, the force that extends in the axial direction is greater than the force that the wall of the blank stretches in the radial direction, causing sink marks at the tip of the tooth surface formed on the blank, and reducing the effective length of the tooth surface. Be shorter. Angle α
Is larger, it is difficult to squeeze the blank, but the sink mark generated at the tip of the tooth surface formed on the blank is small. From the test result, the slope (25) (2
It has been found that the angle α formed by 5) is suitably 90 to 120 °.

In the embodiment, the projecting pin (4) is formed by arranging first to fourth four pin members (41), (42), (43), and (44) in a straight line, and directly contacts the blank. A hemispherical projection (41) protrudes from the distal end surface of the first pin member (41). Protrusion (4
1) is quenched, has a high hardness, and has a 5 to 10 μm thick Ti on the projection surface in the same manner as the inner surface of the mold hole (23).
A layer of C, TiCN or TiN is formed. The dice
The first projecting pin member is inserted into the projecting pin slide hole (13) of (3).
(41) is slidably fitted, the tip of the protruding pin member (41) projects into the nib (2), and the tip is located at approximately the center of the length of the torsion ridge (24) in the longitudinal direction and stands by. doing.

The blank B3 is driven into the mold hole (23) by the punch (6) until it hits the projecting pin (4).
About 70% of the total length of B3 is cut into the mold part (22). punch
(6) is retracted, and the ejection pin (4) advances to eject the blank B4. The blank and the first protruding pin member (41) are
5), the friction between the blank and the first protruding pin member (41) is small. Also, since the projection (45) has a point contact at the center of the end face of the blank,
When (4) advances to the protruding side, there is no seizure between the blank and the first protruding pin member (41), and the blank is protruded while rotating smoothly along the torsion ridge (24).

Since the projections (45) are hardened and hardened, even if the projections (45) are repeatedly brought into contact with the blank, the projections (45) can be formed in a short time.
Will not collapse. Further, since the projection (45) is formed with an excellent seizure resistance and wear resistance layer of TiC, TiCN or TiN, it is more effective in preventing seizure with the blank.

Although the blank B4 has the toothless boss b4, but the tooth surface b3 is completed, the toothless boss can be used as it is in connection with the drive shaft or the driven shaft, or No. 4 in FIG. As shown in the figure, a through-hole b9 is formed in the axis of the blank B4, and a shaft can be attached to the through-hole b9 for use. When the toothless boss b4 hinders the meshing with the helical gear of the other party, the toothless boss b4 may be cut and removed as shown by a two-dot chain line L1. On the tooth surface on the opposite side of the toothless boss b4, a slight sink occurs when the blank meat flows and spreads. Therefore, the end including the sink may be cut off from the line L2.

[0018]

FIG. 4 shows another embodiment of the protruding pin (4), in which one of the first protruding pin (41) and the second protruding pin (42) faces each other. A projection (45) is provided at the center of one of the surfaces. In this case, the protrusion (45)
The pin member (41) is easily rotated when a rotational force acts on the first pin member (41) on the blank side because the friction between the adjacent pin members at the point is small. I do. Therefore, when the blank is protruded, when the blank rotates along the torsion ridge, the first pin member (41) in press contact with the blank also rotates, that is, the blank can be smoothly protruded from the mold hole. .

A central portion of one of the opposing surfaces of the second pin member (42) and the third pin member (43), and one of the opposing surfaces of the third pin member (43) and the fourth pin member. Even if a projection is protruded at the center of the surface, the rotation of the pin member on the blank side can be permitted from the projection, so that the same effect as described above can be obtained.

[0020]

FIG. 5 shows another embodiment of the formation of a projection, in which a hole (46) is formed in the center of the end face of the pin member.
The hole surface is quenched to increase the hardness, and a ball having high hardness is fixedly provided or rotatably provided in the hole (46). In the above case, the life of the pin member can be extended by replacing the hard sphere.

In the above embodiment, the steps from the shearing of the wire to the punching of the wire are performed by a multi-stage horizontal transfer press.
The present invention is not limited to this. The bar material is cut to a predetermined length to form a blank, and the blank is subjected to a heat treatment such as pre-forging / forging and, if necessary, annealing, and is further subjected to a bond treatment (surface lubrication). Process), and the blank is subjected to a tooth surface pre-forging / forging process by a vertical or horizontal press,
It goes without saying that the helical gear can be manufactured through the tooth surface completed forging / forging process. The present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a process diagram of the first half of manufacturing a helical gear.

FIG. 2 is a process chart of the latter half of the manufacture of the helical gear.

FIG. 3 is a sectional view of a dice device.

FIG. 4 is a sectional view of a dice device according to another embodiment.

FIG. 5 is an enlarged view of another embodiment of the protrusion of the protrusion pin.

[Description of Signs] (1) Dice device (2) Nib (21) Guide hole (23) Mold part (3) Die (4) Protruding pin (41) First pin member (45) Projection (46) Hole (47) ) ball

Claims (3)

(57) [Claims] 1. A blank is punched into a die hole of a die (3) having a twisted ridge (24) formed on an inner surface of the die hole, and a twist groove is formed on the outer periphery of the blank by the twisted ridge (24) to project. Pin (4)
In the method of manufacturing a helical gear for projecting a blank from a mold hole, the projecting pin (4) has a projection (41) at the center of the blank side end surface, and when the projecting pin (4) projects the blank, the projection of the projecting pin (4) is formed. (41) A method for manufacturing a helical gear, characterized in that a point contact is made at the center of the end face of the blank. 2. A die (3) having a torsion ridge (24) formed on the inner surface of a die hole, a blank is driven into the die hole, and a twist groove is formed on the outer periphery of the blank by the torsion ridge (24). Pin (4)
In the method of manufacturing a helical gear for projecting a blank from a mold hole, the projecting pin (4) is configured by arranging a plurality of pin members in a straight line, and comes into contact with a pin member adjacent to the center of the end surface of at least one pin member. When the protruding pins (4) and (4a) advance and eject the blank, the pin member on the blank side of the two pin members hitting the point has a twisted blank. A method of manufacturing a helical gear, wherein the helical gear advances forward to a protruding side while rotating along with a ridge (24). 3. A die (3) having a twisted ridge (24) corresponding to a tooth surface of a helical gear on an inner surface of a die hole, a punch (6) for driving a blank into the die hole, and a blank driven into the die. And a projecting pin (4) that projects a plurality of pin members, wherein the projecting pin (4) is configured by arranging a plurality of pin members in a straight line, and a pin member adjacent to the center of an end surface of at least one pin member. Alternatively, a helical gear dice device having a projection (45) at the center of the end face of the blank, which is a point contact.