JPS61140343A - Gear rolling apparatus - Google Patents

Abstract

PURPOSE:To attain a greatly reduced vibration of works in a rolling stage by setting auxiliary tools which move together with a rolling tool and also rool works on both sides of the rolling tool for generating teeth on works between the rolling tools. CONSTITUTION:A couple of the rolling tools 10 are oriented in parallel to each other and hold the bar-shaped work 11. The tools 10 are pressed against the work 11 and are moved in respective opposite directions to generate teeth on the surface of the work 11. The auxiliary tools 12 being set on both sides of the rolling tools 10 also roll the work 11 in integral with the rolling tools 10. When a rolling force given by the rolling tools 10 has a pulse shown by the continuous line A, a rolling force shown by the stitch line B given by the auxiliary tools 12 is applied to the work 11 to interpolate the pulse. A composite force of both the above forces is approximately constant as shown by the chain line C, prevents vibration of the work 11 during rolling stage, and manufactures gears having an accurate tooth trace and tooth profile.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gear rolling device for forming a gear gear by rolling.

[Prior art]

In general, gear rolling involves sandwiching a workpiece between a pair of rolling tools and rotating the workpiece while pressing both tools together to create a tooth profile on the surface of the workpiece. In some cases, when a helical gear is formed, a so-called ridge phenomenon occurs in the tooth trace, which significantly impairs the precision of the tooth trace and tooth profile. It was difficult.

The main cause of ridges on the tooth trace is that the workpiece vibrates as the machining forces of the upper and lower tools fluctuate as the tools move. A pressing device has already been proposed (Japanese Patent Laid-Open No. 118237/1983). This device is provided with retaining members that engage from both sides of the workpiece in the radial direction,
This is designed to suppress vibrations in the radial direction of the workpiece during machining.

[Problem that the invention seeks to solve]

However, the fluctuating force generated by rolling is extremely large, and simply suppressing the workpiece from the radial direction with the engaging member is insufficient to suppress the vibration of the workpiece, which poses a problem for practical use. was there.

The present invention has been made in view of the above points, and is a gear rolling machine that can more effectively suppress the vibration of a workpiece during machining and form a gear with good tooth trace and tooth profile accuracy by rolling. The company provides construction and equipment.

[°Means to solve problems]

The present inventor analyzed the cause of vibration of a workpiece during machining, taking as an example a case in which a pinion is rolled by a rack-type tool.

Generally, when a pinion with an odd number of teeth is rolled, the ridges in the tooth traces are noticeable, but they also occur in the case of an even number of teeth.

First, the case of rolling a pinion with an even number of teeth will be explained. In the case of an even number of teeth, as shown in Fig. 4, the upper tool (
The machining situation by 2a) and the machining situation by the upper tool (2b) are in a point-symmetrical relationship with respect to the axis (0) of the pinion (1). This pinion (1) and tool (2a), (2
b) If you look at the engagement situation from above in a perspective view, the fifth
The result will be as shown in the figure. In other words, the solid line is the upper tool (2a)
and the pinion (1), the broken line is the upper tool (2).
b) and pinion (1), respectively. Therefore, the upper tool (2a) and the upper tool (2b)
It is considered that the pushing forces are almost balanced, and no large force is exerted to move the pinion (1) from its fixed position. However, the pushing force of each tool itself changes from moment to moment depending on how much material from the workpiece is removed by the tool. In particular, it varies depending on whether the overlapping engagement ratio is an integer or not. Therefore, as the pinion rotates, the plastic flow resistance of the tool changes, making it easier for the tool to bite into the pinion or being pushed away.On the other hand, in the case of an odd number of teeth, as shown in Figure 6 The machining situation in the cross section perpendicular to the axis of the pinion (1) is as shown in the upper tool (2a).
) and the upper tool (2b), and this meshing situation is shown in a perspective view from above, as in the case of the even-numbered teeth, as shown in FIG. As is clear from this figure, the upper tool (2a
) and the upper tool (2b) are shifted by half a pitch. Figure 8 shows the pushing force exerted by the upper and lower tools from the lateral direction for each tooth of the upper and lower tools (2a) and (2b), and shows the position of action on the pinion (1) by each tooth of the upper and lower tools. It can be seen that since the pinion (1) is deviated, a moment is acting to rotate the pinion (1) within the pushing force action plane that includes the axis of the pinion (1). From the above, when rolling an odd-numbered tooth pinion, in addition to the variable machining force exerted by each tool as in the case of rolling an even-numbered tooth, an attempt is made to shift the pinion axis from the axis connecting the two centers. It is clear that moments act periodically.

Furthermore, it can be seen that the tooth trace error curve of the even-numbered tooth pinion is periodically subjected to a uniform force over the entire pinion axial direction, as shown in FIG. On the other hand, the odd-numbered tooth pinion is as shown in Figure 10, and it can be seen that both ends of the teeth are subjected to a force that greatly deviates from the normal center-to-center axis position due to the rotational moment, and the error ' is amplified. . In addition,
In FIGS. 9 and 10, (2) indicates the tooth width.

From the above machining force analysis, it is clear that if the machining force applied to the workpiece from one tool is always constant throughout the entire pinion axial direction, the workpiece and tool will be It is possible to eliminate vibration, and therefore, in the gear rolling device according to the present invention, an auxiliary tool is disposed on the side of both rolling tools to move integrally with each of these tools to process the workpiece. , with these auxiliary tools,
It was decided to apply processing force that complements the pulsation of processing force applied to the workpiece by both of the rolling tools described above.0 [Operation] In the present invention, the overall By equalizing the pushing force, vibration of the workpiece is suppressed.

〔Example〕

The present invention will be explained below based on illustrated embodiments.

FIG. 1 is a perspective view showing a gear rolling process performed by a gear rolling device according to an embodiment of the present invention, and FIG. 2 is a plan view of one of the tools. In the figure, αO) is a rack-type rolling tool, and these rolling tools αO) are arranged in pairs in parallel, upper and lower, and between them, the round bar-shaped workpiece double-rolling tools α0) are auxiliary tools (to) on both sides. is installed, the rolling tool α0) and the auxiliary tool (2) are integrated into the workpiece (
11).

The machining force applied to the workpiece (11) by this auxiliary tool (2) is set as shown in FIG. In other words, when the machining force by the rolling tool ←0) causes pulsations as shown by the solid line (A) in the same figure, the pulsation of the main rolling tool αO) is supplemented by the auxiliary tool (2) by the broken line (B). ) Apply the processing force as shown. As a result, the rolling tool (10)
The composite machining by both the auxiliary tool (2) and the auxiliary tool (2) becomes substantially constant as shown by the chain line (C), and it is possible to prevent the workpiece (6) from vibrating during machining.

The shape of the auxiliary tool (to) related to plastic working is shown in the diagram.
The tool is not limited to this, but may have a tooth profile similar to that of the main rolling tool (10), or may have simple irregularities such as a mold for forming an oil bottle. In short, any device that can apply machining force to the workpiece at regular intervals and supplement the pulsation of machining force by the rolling tool (10) is fine. Therefore, for example,
It is also possible to mold screws, splines, etc. at the same time as gears.

In addition, it is not limited to the case where the auxiliary tool (2) is provided on both sides of the rolling tool αO) as in the above embodiment, but it is also possible to use the auxiliary tool (2) only on one side.
12) may be attached. Even when the auxiliary tools (2) are provided on both sides, the shape and phase of both are not restricted to each other, and it is sufficient if the machining force can be made constant as a whole. Furthermore, it goes without saying that the present invention is applicable not only to devices using rack-type tools but also to rolling devices using pinion tools. For example, since vibration of the workpiece during rolling can be significantly reduced, gears with highly accurate tooth traces and tooth profiles can be manufactured.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a gear rolling device according to an embodiment of the present invention, FIG. 2 is a plan view of a rolling tool and an auxiliary tool, and FIG.
The figure is a graph showing the machining force applied to the work by both tools, and Figures 4 to 10 are diagrams explaining the analysis of the machining force when rolling a pinion using a rack type tool.
Fig. 4 is an axis-perpendicular sectional view of the even-numbered tooth pinion, Fig. 5 is a perspective view from above showing the meshing state of the even-numbered tooth pinion and the tool, and Figs. 5 is a diagram corresponding to FIG.
Fig. 0 shows a tooth lead error curve of a binion due to rolling processing, Fig. 9 shows an even-numbered tooth, and Fig. 10 shows an odd-numbered tooth. Shout: Rolling tool Qη: Work (to): Auxiliary tool Fig. 4 Fig. 5 Fig. 6 Fig. 7 m a

Claims (1)

[Claims] In a gear rolling device that forms a tooth profile on the surface of a workpiece by holding a workpiece between a pair of rolling tools and rotating the workpiece while pressing these two tools together, these tools are attached to the sides of both of the rolling tools. Auxiliary tools are provided that move integrally with each of the rolling tools to process the workpiece, and these auxiliary tools apply a machining force that complements the pulsation of the machining force applied to the workpiece from both of the rolling tools. Characteristic gear rolling equipment.