JP3660705B2 - Gear forming method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a gear molding method, and more particularly, to a molding method for molding and deforming a gear material with high accuracy, efficiency, and low cost.
[0002]
[Prior art]
Conventionally, gears have been manufactured using cold or hot forging (forging) by crushing a predetermined gear material into a desired shape or squeezing the same material.
[0003]
[Problems to be solved by the invention]
However, in these cases, tooth formation on the side surface of the gear material, inner surface processing of the same material, chamfering processing of the edge portion of the same material, etc. are often performed in separate steps. Therefore, the number of processes is large, and each time the process changes, it takes time to change jigs and tools, resulting in low productivity and high manufacturing costs.
[0004]
Further, the conventional method often has a problem in terms of processing accuracy. For example, when chamfering the upper and lower end portions of the gear material, first, one end edge portion is processed, and then the gear material is turned over to process the other end edge portion. In this case, there is no problem if the relative positional relationship between the chamfered portions at both end edges is arbitrary, but when specified (for example, Chamfer Yamashita and Tani Doshi to be formed on both ends are concentric. In the case where it is desired to align them, it is necessary to align the phase (position) of the double-sided portions. This phase (position) alignment is generally performed using a phase alignment jig, but the operation is troublesome, takes time, and easily causes errors. This is because if such an error occurs, the desired processing accuracy cannot be obtained.
[0005]
The present invention solves the above-described problems, and an object of the present invention is to provide a molding method for molding and deforming a gear material with high accuracy, efficiency, and low cost.
[0006]
[Means for Solving the Problems]
The gear molding method according to the first aspect of the present invention includes an insertion hole formed in a chamfered lower mold part forming a bottom surface of a molding hole part in which a gear material is set, and a first part formed near the periphery of the chamfered lower mold part. Two chamfered teeth, a molding tooth formed on the ring-shaped portion forming the inner peripheral surface of the molding hole, and a lower surface serving as a contact surface between the forging die provided and the upper surface of the gear material. In a method of forming a gear by performing molding deformation of the gear material by bringing a predetermined forging punch provided with a first chamfered tooth near the periphery, and forming the gear into the forging die. A first step of setting, and the forging punch in which a phase alignment guide rod protrudes from the lower surface moves from a top dead center to a bottom dead center, and at least the tip end side of the guide rod slides into the insertion hole. The first chamfered tooth and the second surface are inserted so as to be movable. The second step in which the tooth and the molded tooth process the gear material, the forging punch located at the bottom dead center is moved to the top dead center, and the guide rod is used as an arrow thread for inner surface processing. A third step of replacing the chamfered lower mold part from the forging die and moving the forging punch from a top dead center to a bottom dead center, and the arrow-sticking bar moves the inner surface of the gear material. A fourth step of machining, and a fifth step of moving the forging punch located at the bottom dead center to the top dead center and taking out the gear material from the forging die. The “gear material” may be a solid material that has not been subjected to rough processing, or may be a material that has been rough processed in advance.
[0007]
The upper SL each "chamfering teeth" is the type of surface to be formed on gear material for is not particularly limited, for example, "chamfer surface" can be exemplified by such as "C face".
[0008]
Further, the outer shape, the cross-sectional shape and the like of the “guide rod” are not particularly limited as long as the object of the present invention can be achieved. For example, a guide rod having a polygonal, circular, or elliptical cross-sectional shape can be exemplified. However, in order to perform more accurate phase alignment, it is preferable to have an asymmetric cross-sectional shape and a cross-sectional shape with a small symmetry axis (such as a trapezoid).
Further, the cross-sectional shape and the like of the “insertion hole” are selected in accordance with the outer shape and cross-sectional shape of the guide rod.
[0009]
Further, as the guide rods, broach for inner surface machining, cut sleeve or the like Ru is illustrated.
[0011]
[Action]
In the molding method of the first invention, at least three or more molding deformations of the gear material are performed in one step in which a forging punch (hereinafter referred to as “punch”) moves from top dead center to bottom dead center. . Therefore, the number of steps required for forming the gears can be reduced, so that the production efficiency can be improved and the production cost can be reduced.
[0012]
In the second invention, a first chamfered tooth is provided near the periphery of the lower surface of the punch, and a second chamfered tooth is provided near the periphery of the bottom surface of the forming hole portion of the forging die (hereinafter referred to as “die”). It has been. Therefore, the chamfer molding of the upper and lower edge portions of the gear material can be performed in the “one step”.
In addition, a guide rod is disposed so as to protrude from the approximate center of the lower surface, and an insertion hole is provided at the approximate center of the bottom surface so that at least the tip side of the guide rod can be slid.
[0013]
Therefore, when the punch is moved from the top dead center to the bottom dead center, the positional relationship between the punch and the die is uniquely determined only by fitting the tip end side of the guide rod into the insertion hole. For this reason, even when the relative positional relationship between the chamfers (locations) at both end edges is specified, it is not necessary to perform the phase alignment work as long as the arrangement of the chamfered teeth is accurate. As a result, the manufacturing efficiency can be further improved and the manufacturing cost can be reduced, and the desired processing accuracy can be obtained with certainty.
[0014]
Moreover, in this 3rd invention, instead of the guide bar of the said 2nd invention, the arrow threading rod for an inner surface process protrudes and arrange | positions from the approximate center of the lower surface of a punch. Therefore, when the gear material is cylindrical, inner surface processing can be performed in the “one step”.
In this 4th invention, the shaping | molding tooth | gear which performs tooth | gear formation is provided in the internal peripheral surface of the hole for molding of die | dye. Therefore, in the above "one step", teeth can be formed on the gear material.
[0015]
【Example】
Hereinafter, the present invention will be described specifically by way of examples.
(1) Example 1
In this example, the gear material 3 was formed using a punch 1 and a die 2 as shown in FIG. However, this figure is a partial perspective view showing a state where the punch 1 is at the top dead center.
The punch 1 has a substantially cylindrical shape on the lower end side, and includes a first chamfering tooth 11a near the periphery of the lower surface 11, and a guide bar 11b that protrudes downward from a substantially central side of the lower surface 11. ing.
[0016]
Of these, the first chamfered teeth 11 a form chamfers on the upper edge 31 of the gear material 3, and a plurality of substantially mountain-shaped protrusions are arranged along the periphery of the lower surface 11. It is.
The guide bar 11b has a substantially rectangular cross section. However, the cross-sectional shape of the guide bar 11b is not limited to this, and may be a triangle, a rectangle, a trapezoid, a rhombus, an ellipse, or the like.
[0017]
The die 2 has a substantially cylindrical container shape, and includes a chamfered lower mold portion 21 disposed on the lower side and a ring-shaped portion 22 placed thereon.
Among these, the chamfered lower mold portion 21 constitutes the bottom surface side of the die 2 and includes a second chamfered tooth 21a similar to the first chamfered tooth 11a on the peripheral side. The second chamfered tooth 21 a forms a chamfer on the lower edge portion 32 of the gear material 3. And these chamfering teeth 11a and 21a will be in the state which mutually aligned the mountain comrades and the valley comrades in the concentric concentric position. In this embodiment, the chamfered teeth 11a and 21a are used for forming a chamfer, but may be formed as a C surface, a corrugated surface, or other types of surfaces.
[0018]
Further, a square hole 21b having a hole shape corresponding to the outer shape of the guide rod 11b is provided near the center of the lower mold part 21. This square hole 21b is for inserting the tip end side of the guide rod 11b in a sliding state when the punch 1 moves to the bottom dead center side.
[0019]
The ring-shaped portion 22 has a toroidal outer shape, and has a molding tooth 22 a that forms teeth on the side surface 33 of the gear material 3 on the inner peripheral surface thereof. However, it is not always necessary to form teeth on the side surface 33 of the gear material 3. For example, a predetermined groove (for example, a groove like a hook groove of a nut) may be formed. In this case, instead of the molded tooth 22a, a corresponding tooth is used.
Then, the ring-shaped portion 22 is placed on the lower mold portion 21 in an aligned state, and a space surrounded and formed by the ring-shaped portion 22 becomes a forming hole 28 of the die 2.
[0020]
The gear material 3 has a substantially cylindrical outer shape, and is a solid material that is not subjected to any pre-processing. However, the outer shape of the material 3 is not limited to this, and may be a material having another shape such as a columnar shape or a prismatic shape (including a hollow shape). Further, instead of using such a solid material, a material subjected to rough processing in advance may be used. For example, coarse teeth may be formed on the side surface 33. In this case, coining or sizing molding is performed by the molding teeth 22a.
[0021]
In this embodiment, first, as shown in FIG. 1, after the punch 1 is moved to the top dead center, the gear material 3 is set in the molding hole 28 of the die 2. Then, by operating a predetermined switch (not shown), the punch 1 is lowered, the tip side thereof is entered into the molding hole 28, and the punch 1 is further lowered to the bottom dead center. To complete the process. Next, after the punch 1 is moved to the top dead center, the formed gear is taken out by a predetermined knockout mechanism (not shown). Further, if the above operations are repeated sequentially, the same gear can be formed continuously.
[0022]
In the present embodiment, as described above, during the “one step” in which the punch 1 is moved from the top dead center to the bottom dead center, the gear blank 3 is plastically deformed, and the chamfers are attached to both end portions 31 and 32 thereof. To form teeth on the side 33. In this way, since three molding deformations are performed at a time, the number of steps required to form the gears is reduced, so that the production efficiency can be improved and the production cost can be reduced.
[0023]
Further, when the punch 1 moves to the bottom dead center, the guide rod 11b is inserted into the rectangular hole 21b, so that the punch 1 maintains the correct positional relationship with respect to the die 2. For this reason, even if it is desired to align Chamfer's Yamashita and Tanishi at the same concentric position, there is no need to perform the troublesome work for phase alignment of the chamfered teeth 11a and 21a. When the positional relationship between the chamfers is arbitrary, the guide rod 11b may be removed from the punch 1.
[0024]
(2) Example 2
In the present embodiment, in addition to the molding of each part of the gear material 3 shown in the first embodiment, the finishing process of the inner surface 34 of the same material 3 is performed.
The punch 1c used in the present embodiment is obtained by removing the guide bar 11b from the punch 1 similar to that in the first embodiment, and attaching an arrow passing bar 11c as shown in FIG. The arrow stick 11c is a broach for finishing the inner surface. However, the arrow passing rod 11c is not limited to the broach, and may be a drill sleeve or the like for tapering the inner surface.
[0025]
A die 2c that does not have the square hole 21b was used. Furthermore, the gear material used in the present embodiment (however, illustration in FIG. 2 is omitted) is the same as that in the first embodiment. Other points are the same as in the first embodiment.
In this embodiment, since the inner surface of the gear material is also finished while the punch 1c moves from the top dead center to the bottom dead center, the manufacturing efficiency can be further improved and the manufacturing cost can be reduced. .
[0026]
In this embodiment, the guide rod 11b is not used when the gear is formed. However, chamfers can be provided on the upper and lower ends of the material with the same accuracy as in the first embodiment by the following method. That is, the die 2 similar to that of the first embodiment is used, and the guide rod 11b is attached to the punch 1c instead of the arrow passing rod 11c. In this state, the punch 1c is moved from the top dead center to the bottom dead center. 2 and the punch 1c are aligned. Then, in this aligned state, the guide rod 11b is removed from the punch 1c, the arrow passing rod 11c is attached, the parts constituting the die 2 are replaced, and the die 2c without the square hole 21b is obtained. The gear may be formed.
[0027]
The present invention is not limited to the specific examples described above, and various modifications can be made within the scope of the present invention depending on the purpose and application. That is, in this embodiment, teeth are formed on the outer peripheral surface of the gear material, but teeth can also be formed on the inner peripheral surface.
[0028]
【The invention's effect】
In each of the present inventions, in a "one step" until the punch reaches the bottom dead center from the top dead center , teeth are formed on the side surfaces of the gear material and chamfers are formed on both ends thereof. The inner surface of the gear material can be processed. Thereby, the manufacturing efficiency of the gear can be improved and the manufacturing cost can be reduced. In particular, the interaction of the insertion hole provided in the guide rod and die provided in the punch, the upper and lower ends of the material for the gears, it is easy to form a chamfered portion that is firmly of alignment with each other is there.
[Brief description of the drawings]
FIG. 1 is a partial perspective view for explaining a punch, die, and gear material used in Example 1. FIG.
FIG. 2 is a partial perspective view for explaining a punch and a die used in Example 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 1c; Punch, 11; Lower surface, 11a; 1st chamfering tooth, 11b; Guide rod, 2; Die, 21; Chamfering lower mold part, 21a; 2nd chamfering tooth, 21b; , 22a; molding tooth, 28; molding hole, 3; gear material, 31, 32; upper edge of gear material, 32; lower edge of gear material, 33; gear Side surface of the material for a gear, 34; Inner surface of the material for a gear, 35; Upper surface of the material for a gear, 36; Lower surface of the material for a gear, 11c;

Claims (1)

An insertion hole formed in the chamfered lower mold part forming the bottom surface of the molding hole part in which the gear material is set, a second chamfered tooth formed near the periphery of the chamfered lower mold part, and the inside of the molding hole part Molding teeth formed on the ring-shaped part forming the peripheral surface are provided with a forging die, and
A predetermined forging punch provided with a first chamfering tooth is provided in the vicinity of the periphery of the lower surface that is a contact surface with the upper surface of the gear material, and the gear material is subjected to molding deformation to change the gear material. In the molding method,
A first step of setting the gear material on the forging die;
The forging punch, in which a phase alignment guide rod protrudes from the lower surface, moves from the top dead center to the bottom dead center, and at least the tip side of the guide rod is slidably inserted into the insertion hole , A second step in which the first chamfered tooth, the second chamfered tooth, and the molded tooth process the gear material;
The forging punch located at the bottom dead center is moved to the top dead center, and the guide rod is replaced with an arrow threading rod for inner surface processing, and the chamfered lower die portion is replaced from the forging die. Process,
A fourth step in which the forging punch is moved from the top dead center to the bottom dead center, and the arrow stick is used to process the inner surface of the gear material;
And a fifth step of moving the forging punch located at the bottom dead center to the top dead center and taking out the gear material from the forging die .

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