JPH03287320A - Method for manufacturing teethed part - Google Patents

Abstract

PURPOSE:To prevent alignment error of a partially formed blank during holding and cutting it by gripping its outer peripheral surface with jaws of a holder. CONSTITUTION:A forged blank W5 having a teethed portion 1 is formed by successively forging it from a cylindrical blank W0. Next, a partially formed blank W6 is formed by forging it so that the teethed portion 1 of the forged blank W5 be finished to the required size. After that, a cut blank W7 is finished by successively cutting it through holding the addendum surface of the teethed portion 1 of the partially formed blank W6.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention = [Industrial Application Field] The present invention relates to a method of manufacturing a product having a toothed portion, such as a gear used in an automobile engine, for example.

[Conventional technology]

Conventionally, when manufacturing a product having teeth such as a gear as shown in FIG. 7, a pre-forged material W4 is formed by a forging process as shown in FIGS. 1 to 4 and FIG. 13.

That is, a cylindrical cylindrical material WO (FIG. 1) obtained by cutting a round bar material to a required length is formed into a flat disk-like material Wl (FIG. 2) whose diameter is larger than that of the cylindrical material WQ, and Next, the diameter of the disk material W1 is further expanded slightly, and a convex portion 9 protruding from one end surface in the axial direction of the disk material W1 is formed into a preformed material W2 (FIG. 3) having a concave portion 10 recessed in the other end surface. Then, the preformed material W2 is formed into a pierced material W8 (Fig. 4) having a 6-circular pierced hole 6 extending in the axial direction, and the pierced material W3 is further extruded. The protrusion 9 has a groove 2 concentrically with the pierced hole 6 and recessed circumferentially outward from the pierced hole 6 on the molded end surface of the convex portion 9 , and a groove 2 on the molded side end surface of the concave portion 10 . Pre-forged material W4 (first
8. Shape the shape.

Next, an intermediate formed material W6 (Fig. 6,
Figure 8) is molded.

Finally, the intermediate formed material W6 is held using the tooth surface 52 of the tooth portion 1 as a reference, and the inner circumference of the pierced hole 6, the forming side end surface of the convex portion 9, and the outer circumference of the large diameter portion 4, which serve as the machining reference plane, are sequentially cut. After processing, the inner periphery of the pierced hole 6 is held as a reference, and the end face of the concave portion 10 is cut to obtain a cut product W7 (
Figure 7) is molded.

Here, when cutting the processing reference surface, the means for holding the intermediate formed material W6 shown in FIGS. 6 and 8 will be explained. 1. As shown in FIG. 14, first press the root end surface of the intermediate molded material W6 against the reference surface 146 of the reference stand 143 which is divided into three parts in the circumferential direction, and then divide the part between the reference parts 143 into three parts in the circumferential direction. As shown in FIG. 15, the tooth surface 52 of the tooth portion 1 of the intermediate molded material W6 is pressed and held by the tip of a pin 147 provided at the tip of the axis side of the movable table movable toward the axis. Was.

[Problem to be solved by the invention]

According to the method for manufacturing a product having teeth as described above, after forming the teeth 1 on the outer peripheral surface of the small diameter portion 3 of the pre-forged material W4, the tooth surface 52 of the teeth 1 is pressed from three directions with the tip of the pin 147. Since cutting is performed while holding the pin 147 while holding it, indentations are formed on the tooth surface 52 that the tip of the pin 147 comes into contact with, causing problems such as abnormal noise. Furthermore, since the tooth surface 52 is held by being pressed against the tip of the pin 147 from three directions, the holding force cannot be increased, and as a result, slight deviations may occur during machining. Furthermore, if the number of teeth of the product changes, the pawl 133 and pin 147 must be replaced accordingly, which leads to a decrease in productivity.
There is a serious problem.

Therefore, it is an object of the present invention to solve these problems and provide a product having teeth of good quality and high productivity.

=Structure of the invention= [Means for solving the problem] A forging process for forming a forged material having teeth by sequential forging from a cylindrical cylindrical material, and finishing the teeth of the forged material to predetermined dimensions. The sizing process involves molding an intermediate molded material, and the cutting process involves holding the tooth tip surfaces of the teeth of the intermediate molding material with a holder and sequentially cutting them to form a machined product to a predetermined size. It is characterized by being configured.

[Examples and effects]

Embodiments of the present invention will be described below based on the drawings.

1 to 7 are a plan view and a cross-sectional plan view sequentially showing a method of manufacturing a product having teeth according to an embodiment of the present invention.

First, in the continuous forging process, a cylindrical cylindrical material WO (Fig. 1) is prepared by cutting a round bar material to the required length in advance, and a flat disc material Wl (Fig. Next, the disk material W1 is further slightly expanded in diameter, and a preformed material W2 (a preformed material W2) having a convex portion 9 protruding from one end surface in the axial direction of the disk material W1 and a concave portion 10 recessed from the other end surface. 3), and then the preformed material W2 is formed into a pierced material W3 (FIG. 4) having a pierced hole 6 concentric with its axis and penetrating in the axial direction. By extrusion molding, the convex part 9 has a groove part 2 concentric with the pierced hole 6 and recessed circumferentially on the outer diameter side of the pierced hole 6 on the molded side end face of the convex part 9, and a groove part 2 on the shaped side end face of the concave part 10. A forged material W5 (FIG. 5) is formed, which has a large diameter flat groove portion 8 continuous with the pierced hole 6, and a small diameter portion 3 that protrudes in an annular shape and has teeth 1 on the outer peripheral surface.

Next, an intermediate formed material W6 (FIGS. 6 and 8) is formed by forming the tooth portion 1 of the forged material W5 to a predetermined finished dimension by sizing processing.

Finally, the intermediate molded material W6 is applied to the tooth tip surface 5 of the tooth portion 1.
1 is held by a holder 31, and successively cut to form a cut product W7 (FIG. 7) having predetermined dimensions.

Hereinafter, in the above-mentioned process, the pierced material W3 is forged with the formed material W.
5, the process of forming the forged forming material W5 into an intermediate forming material W6, and the process of forming the intermediate forming material W6 into a cut product will be described in detail.

In the process of forming the pierced material W3 into a forged material W5 without trenching, as shown in FIG. get. This extrusion mold 11 has a lower mold 12 having a tooth profile 19 and an upper mold 14 having an upper punch 13. A mandrel 15 that loosely fits into the hole of the lower mold 12, and a cylindrical sliding member 16, such as a knockout ring, that fits slidably onto the mandrel 15.
17 provides a die engraving space 18 within the lower die 12 in which the shape of the material is to be defined by buttoning.

The tooth profile 19 of the lower mold 12 is formed by extruding the pierced material W3 in the axial direction to form a small diameter portion 3 of the forged material W4 and a plurality of tooth portions 1 extending along the axial direction on the outer peripheral surface of the small diameter portion 3. It is provided in the hole of the lower mold 12 in the axial direction for rough molding.

When obtaining the forged material W4 using such an extrusion mold 11,! As shown in the left half of FIG. 9, the piercing material W3 is placed in the engraving space 18 of the lower mold 12,
By displacing the upper mold 14 and the upper bunch 13 downward, as shown in the right half of FIG. A plurality of tooth portions 1 along the axial direction are roughly formed on the outer peripheral surface of the portion 3.

Next, the step of forming the forged material W5 into an intermediate material W6 is performed using a sizing die 21, as shown in FIG.

The sizing die 21 includes a lower sizing die 24 having a knockout 22 provided to tightly engage with the inner diameter of the forged material W5 and a guide ring 23 fitted onto the knockout 22 in its central hole; A finishing tooth profile 27 having substantially the same shape as the product is formed in the axial direction on the inner peripheral surface of the lower sizing mold 24 and from the upper mold 26 having a push punch 25 facing the lower sizing mold 24 .

When performing sizing using such a sizing die 21, the forged forged material W5 is carried into the sizing die 21 as shown in the left half of FIG. 10, the small diameter portion 3 is enlarged from the inner diameter by lowering the pushing punch 25 of the upper die 29 and pressing the forged material W5. The tooth portion 1 is formed into a predetermined shape.

Subsequently, the intermediate molded material W6 sized in this manner is extruded from the sized puffer lower mold 24 by the knockout 22 to form an intermediate molded material W6.

Finally, the intermediate molded material W6 is cut to form a cut product W7. In this cutting step, as shown in FIGS. 11 and 12, the intermediate formed material W6 is held by a chuck device and cut.

The chuck device has a cylindrical main body 42 having a rail 36 formed in a groove shape toward the axial center at a position divided into three parts in the circumferential direction, and is engaged with the rail 36 of the main body 42 and is movable in the axial direction. It has a holder 31 and a reference stand 43 for setting the processing reference in the axial direction of the intermediate molded material W6.

The main body is connected to a main shaft (not shown) through a plurality of bolts 45 and rotates together with the main shaft.

Further, in the holder, a movable base 32 having a wavy portion 38 having a wavy bottom portion is integrated with a mounting base 37 having a wavy portion 39 that engages with the wavy portion 38 by a bolt 34, and is axially relative to the base. Move toward the heart. Further, on the axis side of the movable table 32, a claw 33 having a curvature surface at its tip that engages with the tooth tip surface 51 of the intermediate molded material W6 is fixed by a bolt 35.

The reference stand 43 has a reference surface 46 at the tip in the axial direction for setting the axial processing reference of the intermediate formed material W6, and bolts are placed between the holder 31 divided into three parts in the circumferential direction. 4
It is fixed by 4.

When holding the intermediate forming material W6 with such a chuck device and performing cutting processing, the dedendum end surface 5 of the intermediate forming material W6 is pressed against the reference surface 46 of the reference stand 43, and in this state it is rotated in three directions. The holder 31 then moves toward the tooth tip surface 52 of the intermediate molded material W6, and the tip of the claw 33 of the holder 31 presses and holds the tooth tip surface 52.

Subsequently, the cutting tool 41 advances toward the intermediate formed material W6, sequentially processes the outer circumferential surface of the large diameter portion 4 and the curved side end surface of the convex portion 9, and then retreats. Continuously, the groove 2 and the inner diameter of the pierced hole 6 are sequentially machined using a cutting tool (not shown).

Thereafter, the outer circumferential surface of the large diameter portion 4 of the intermediate formed material W6 is held using a cutting device (not shown), and the flat groove portion 8 on the end surface of the concave portion 10 is formed.
The inner diameter is sequentially machined to form a cut product W7.

In this way, the tooth part 1 is made by sequential forging from the cylindrical material WO.
By forming the forged material W5 having the following properties, and sizing the tooth portion 1 of the forged material W5 and finishing it to a predetermined dimension, it is possible to obtain high accuracy not only on the tooth surface 51 but also on the tooth tip surface 52. During machining, the tooth tip surface 52 can be held as a cutting reference.

Effects of the Invention As described above, according to the present invention, there is a forging process of sequentially forging a cylindrical material into a forged material having teeth, and finishing the teeth of the forged material to predetermined dimensions. The sizing process involves molding an intermediate molded material, and the cutting process involves holding the tooth tips of the intermediate molding material with a holder and sequentially cutting them to form a machined product to a predetermined size. Because of this structure, high accuracy can be obtained even if the tooth part of the intermediate formed material after the sizing process is buttoned not only on the tooth surface but also on the tooth tip surface, so in the cutting process in the subsequent process, the tooth tip surface can be used as the cutting reference. Can be retained. In other words, the outer circumferential surface of the intermediate molded material can be held in surface contact by the claws of the holder, so even if the holding force is increased, no impressions will be made, and the intermediate molded material will not shift during holding or cutting. .

Furthermore, even if the number of teeth of the product changes, as long as the diameter does not change, continuous machining is possible, which improves productivity.

[Brief explanation of the drawing]

Figures 1 to 12 show a method for manufacturing a product having teeth according to an embodiment of the present invention, and Figures 1 to 7 show the material changes in Step 1 of forming a machined product from a cylindrical material. 8 is a front view showing the intermediate formed material, FIG. 9 is a partial sectional plan view showing the forging process, and FIG.
11 is a partial side view showing the chuck device, and FIG. 12 is a partial cross-sectional plan view showing the intermediate forming material attached to the chuck device. Figures 13 to 15 show a conventional manufacturing method for products with teeth, Figure 13 is a cross-sectional plan view of a pre-forged material formed from piercing material, and Figure 14 shows a chuck device. Partial side view, FIG. 15 is a partially enlarged side view showing a state in which the intermediate molding material is attached. (Explanation of symbols) WO... Cylindrical material. W5...Forged material. W6...Intermediate molding material. W7... Cutting product (product with teeth). 1... Tooth part 31... Maintenance
Holder. 51... Tooth tip surface. Figure 6 Figure 7 Figure 8 Figure 14

Claims (1)

[Claims] Tooth portion 1 is formed by sequential forging from a cylindrical cylindrical material W_0.
a forging step of forming a forged formed material W_5 having A method for manufacturing a product having a tooth portion, which comprises a cutting process in which a tooth tip surface 51 is held by a holder 31 and a cut product W_7 finished to a predetermined dimension is formed by sequential cutting.