JPS6358066B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flat die for rolling helical gears, oil grooves, etc., helical teeth or helical grooves by sandwiching the object to be rolled and moving it relative to each other. Alternatively, it relates to a flat die that is effective for forming grooves.

For example, as a method for manufacturing the helical gear 1 shown in Fig. 1, cutting with a hob cutter or the like or rolling may be considered, but the cutting method takes a long time, and the finished dimensions of the hob Since this must be taken into account in the product, unnecessary parts become longer, resulting in larger products and higher tool costs. On the other hand, the rolling method has features such as high production efficiency and strong teeth, and therefore does not suffer from the problems mentioned above with the cutting method. Since this method applies a large load to the structure and causes it to undergo plastic deformation, it is difficult to achieve sufficient accuracy, especially when manufacturing rolled products such as small-diameter helical gears. The reality is that they are manufacturing.

That is, when rolling the helical gear 1 using a flat die, for example, the object 2 to be rolled is sandwiched between a pair of flat dies 3 and 4 as shown in FIG. 2, and a load P is applied. In this state, each of the flat dies 3 and 4 is moved in a relatively opposite direction to rotate the object 2 to be rolled. In particular, in the case of a helical gear 1 with an odd number of teeth, the object 2 to be rolled and the flat die 3 are rotated. , 4 changes, resulting in a tooth trace error. FIG. 3 is a diagram for explaining the movement of the meshing points, and when the rolled product 2 is at the position indicated by A with respect to one flat die 3, the two are at points a1, a2, and a3. It is interlocked at three points,
When the rolled object 2 moves relatively to the position indicated by B in FIG.
On the other hand, the other flat die 4 and the rolled object 2 engage at 4 points when the rolled object 2 is at the position shown by A, contrary to the case shown in FIG. When it is in the position shown by B, it engages at three points. When rolling a helical gear 1 with an odd number of teeth in this way, the number of meshing teeth and the meshing point change, and the number of meshing teeth and the meshing point change between one flat die 3 side and the other flat die 4 side. Since the point positions are different, the amount of pushing into the rolled object 2 by the flat dies 3 and 4 changes. As a result, the load acting on the rolled object 2 changes and the rolled object 2 is displaced or deformed even slightly in the direction indicated by the arrow in FIG. 2, so the formed tooth trace 5 is shown in FIG. 4. The pitch interval in the axial direction of the teeth in the rolled object 2 is as follows.
It becomes undulating in the same pitch as Pa. Such an error e would not occur if the displacement or deformation of the rolled object 2 could be prevented, but theoretically, the rolled object 2
Although it is possible to prevent its displacement or deformation by making it a rigid body, this is practically impossible.

In this way, in the past, due to the large tooth trace error when rolling, it was not possible to obtain rolled products such as helical gears with a precision that could be used for practical purposes, and as a result, in many cases, rolling products were The reality is that they manufacture helical gears, etc.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a flat rolling die that can accurately roll helical gears with an odd number of teeth, helical grooves, etc. The feature of this invention is that among the flat dies in which a finishing tooth group is formed following a biting tooth group formed so that the tooth height increases in sequence, each biting tooth group in the biting tooth group is The auxiliary teeth are formed in between, and the tooth depth of each auxiliary tooth is less than the tooth depth of the biting teeth and is configured to gradually become lower from the starting end side of the biting tooth group to the finishing tooth group side. Therefore, in this invention, while rolling is performed using the biting tooth group, since the number of teeth of the object to be rolled becomes a substantially even number, each flat die is There is no change in the number of meshing teeth and the meshing point with the object to be rolled, and as a result, waviness on the tooth surface of the object to be rolled can be prevented and tooth trace errors can be made as small as possible.

Embodiments of the present invention will be described below with reference to FIGS. 5 to 8. In the embodiments described below, the pair of flat dies that sandwich the object to be rolled have the same configuration, so the configuration of only one of the flat dies will be described to avoid duplication of explanation.

FIG. 5 and FIG. 6 are schematic diagrams showing one embodiment of the present invention, and the flat die 10 shown here is
It is configured as a flat die for rolling helical gears with odd number of teeth in which helical teeth are formed on the surface of the base 11, and from one end of the base 11 (the right end in FIGS. 5 and 6) of these helical teeth. A plurality of helical teeth in a predetermined range are defined as a biting tooth group 12, a plurality of helical teeth in a subsequent predetermined range are defined as a finishing tooth group 13, and a predetermined range of helical teeth on the other end side of the base body 11 are defined as a finishing tooth group 13. A plurality of helical teeth constitute a relief tooth group 14.

The biting tooth group 12 is for gradually biting into the outer periphery of the cylindrical rolled object 2 to form so-called coarse teeth on the rolled object 2, and is formed of helical teeth on one end side of the base body 11. The tooth depth is the lowest, finished tooth group 1
It is composed of so-called biting teeth 15 whose tooth height gradually increases so that the tooth height of the helical teeth adjacent to 3 becomes approximately the normal tooth height, and auxiliary teeth 16 formed between each biting tooth 15. ing. The auxiliary teeth 16 are not specifically for forming teeth on the object 2 to be rolled, but are for preventing fluctuations in the rolling load on the object 2 to be rolled, and the tooth depth h thereof is shown in FIG. As shown, it is set to be highest on the starting end side (the right end side in FIGS. 5 and 6) of the biting tooth group 12 and gradually become lower toward the finishing tooth group 13 side. The maximum tooth height of the auxiliary teeth 16, that is, the tooth depth at the starting end of the biting tooth group 12, is approximately the same as the tooth depth of the biting teeth 15, and the minimum tooth height, that is, the tooth height at the part adjacent to the finishing tooth group 13. is preferably approximately zero. In addition, the tooth thickness of the biting teeth 15 is set to be the thinnest on the starting end side of the biting tooth group 12 due to the provision of the auxiliary teeth 16, and is set to be gradually thicker thereafter. The thickness is the thickest on the starting end side of the biting tooth group 12,
It is preferable to set the thickness gradually thinner thereafter.

Further, the finishing tooth group 13 includes the biting tooth group 1.
2, the incomplete teeth formed on the object to be rolled 2 by
It consists of so-called finishing teeth 17 for finishing the teeth into regular teeth, and the tooth depth and tooth thickness of the finishing teeth 17 are regular dimensions that match the shape of the intended teeth to be formed on the object 2 to be rolled. is set to .

Furthermore, the relief tooth group 14 is formed by a plurality of helical teeth whose tooth height gradually decreases toward the other end of the base body 11.

Next, the operation of the flat die 10 configured as described above will be explained.

Odd number tooth helical gear 1 formed by the flat die 10
For rolling, as shown in FIGS. 5 and 8, the product 2 to be rolled is sandwiched between a pair of flat dies 10,
In this state, each flat die 10 is moved in opposite directions, and the rolled object 2 is rotated accordingly. At the beginning of rolling, first,
The biting teeth 15 and the auxiliary teeth 16 in the biting tooth group 12 bite into the object to be rolled 2. In that case, when rolling a helical gear 1 with an odd number of teeth, for example seven teeth, the biting teeth 1 of one flat die 10
In the state where three of the biting teeth 15 out of 5 are biting into the object to be rolled 2, in the other flat die 10, four of the biting teeth 15 out of the biting teeth 15 are biting into the object to be rolled 2. , At the same time, the auxiliary teeth 16 provided between the biting teeth 15 are connected to the rolled object 2.
It bites into. The state is shown in FIG. As is clear from this figure, the number of teeth of the object to be rolled 2 is an even number, and the total number of teeth biting into the object to be rolled 2 is the same for each flat die 10, and moreover, the number of teeth biting into the object 2 is the same. The auxiliary teeth 16 bite into the object 2 to be rolled at radially opposite positions, and as a result, the load applied to the object 2 by one flat die 10 and the load applied to the object 2 by the other flat die 10 are reduced. The load on the structure 2 becomes balanced. Therefore, while rolling is being performed by the biting tooth group 12, there is almost no load variation, so
The above-mentioned undulation does not particularly occur. On the other hand,
The auxiliary teeth 16 are configured so that their tooth height h gradually decreases, and eventually disappear, and the amount of biting of the biting teeth 15 into the rolled object 2 gradually becomes deeper, so that the auxiliary teeth 16 Therefore, the recess formed in the object to be rolled 2 gradually bulges out, and when the rolling by the biting teeth group 12 is completed, the recess disappears, and as a result, the number of teeth in the object to be rolled 2 becomes an odd number.

Next, the object to be rolled 2 is engaged with a group of finishing teeth 13 and further processed. In that case, since the number of teeth of the object to be rolled 2 is an odd number, the number of teeth and the meshing point of each flat die 10 that meshes with the object to be rolled 2 will change, but the The teeth in the center have almost a regular shape, and the machining by the finishing tooth group 13 mainly involves modifying the tooth profile without biting into the object 2 to be rolled. Since the machining is carried out with the rolling material 2, even if the number of meshing teeth or the meshing point changes, waviness in the tooth trace direction does not occur on the tooth surface of the rolled product 2.

The rolled object 2, on which teeth of the desired size have been formed by the finishing tooth group 13 as described above, then meshes with the relief tooth group 14, but the tooth height of the relief tooth group 14 is gradually lowered. Since the load acting on the object to be rolled 2 gradually decreases, in other words, the object to be rolled 2 is not particularly processed, and eventually the mesh is disengaged and the rolling is completed. do.

Therefore, according to the above-mentioned flat die 10, while rolling is performed using the biting tooth group 12, the rolling load does not particularly fluctuate, and the finishing tooth group 1
3, even if there is a change in the number of meshing teeth or the meshing point, the load applied to the material to be rolled 2 is small, so no waviness occurs, and as a result, According to the above flat die 10,
It is possible to roll the helical gear 1 with good precision.

In addition, although the above-mentioned embodiment has been explained by taking as an example the case of rolling a helical gear, the flat die of the present invention can also be applied to the case of rolling a helical groove such as an oil groove.

As is clear from the above description, the flat die of the present invention is a flat die in which a finishing tooth group is formed following a biting tooth group formed so that the tooth depths become higher, and each of the biting tooth groups is This is because the secondary teeth are formed between the biting teeth, and the tooth height of each secondary tooth is less than the tooth height of the biting teeth and gradually becomes lower from the starting end side of the biting tooth group to the finishing tooth group side. , while rolling is performed using a group of biting teeth, the number of teeth on the object to be rolled becomes substantially even;
Unlike rolling with an odd number of teeth, there is no change in the number of teeth meshing with the object to be rolled, and as a result, it is possible to prevent waviness on the tooth surface of the object to be rolled and to minimize tooth trace errors. Furthermore, it becomes possible to perform rolling processing of helical gears, etc., which could not be put into practical use due to poor precision in the past, and it is possible to obtain excellent practical effects such as being able to significantly improve productivity.

[Brief explanation of the drawing]

Figure 1 is a front view showing an example of a helical gear, Figure 2 is a schematic front view for explaining the rolling method of a helical gear, and Figure 3 is the number of meshing teeth and meshing point between the rolled object and the flat die. FIG. 4 is a schematic diagram of waviness occurring on the tooth surface of a rolled object, FIG. 5 is a schematic side view showing an embodiment of the present invention, and FIG. 6 is a schematic plane diagram of the same. 7 is an enlarged cross-sectional view taken along the line --- in FIG. 6, and FIG. 8 is a schematic cross-sectional view showing the meshing state of the biting teeth of each flat die with the object to be rolled. 2... Rolled object, 10... Flat die, 12...
Biting teeth group, 13... Finishing tooth group, 15... Biting teeth, 16... Secondary teeth, 17... Finishing teeth, h
...The depth of the accessory teeth.

Claims (1)

[Claims] 1. A finishing tooth group consisting of a plurality of biting teeth whose tooth height gradually increases and is parallel to each other is followed by a finishing tooth group consisting of a plurality of finishing teeth parallel to each other, and arranged facing each other with the object to be rolled in between. In the flat rolling die, a plurality of auxiliary teeth whose tooth depth is set to be less than or equal to the tooth depth of the biting teeth are formed parallel to the biting teeth in the middle part of each biting tooth in the biting tooth group. What is claimed is: 1. A flat die for rolling with odd number teeth, characterized in that the tooth height of the auxiliary teeth becomes gradually lower from the starting end of the biting tooth group toward the finishing tooth group.