JPH0447601Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a rolling machine that plastically forms a tooth profile on the outer periphery of a workpiece using a flat rolling die. This article relates to a rolling machine that can detect quality in real time.

(Prior art) Conventionally, in order to determine whether the shape of a workpiece that has been plastically worked by a rolling machine is within tolerance, that is, whether the machining accuracy is good or bad, dimensional checks using a micrometer or I was looking at the results from a shape measuring device. Although these methods are reliable, they require proficiency in measurement techniques and take time to measure, which delays feedback and sometimes delays countermeasures when defective products occur.

(Problem to be solved by the invention) When rolling is performed using a rolling machine, rolling may occur due to various factors such as rotational fluctuation of the workpiece, breakage of the flat die, or abnormality of the support of the workpiece. The machining accuracy of the workpiece being processed may deteriorate and fall outside the allowable limits. It is necessary to catch such a situation as soon as possible and take countermeasures.

An object of the present invention is to provide a rolling machine capable of detecting in real time whether the machining accuracy of all workpieces is good or bad during rolling. Another object of the present invention is to provide a rolling machine that can easily determine the pitch error of teeth formed on the outer periphery of a workpiece.

(Means for Solving the Problems) Therefore, the present invention provides a rolling machine that plastically forms a tooth profile on the outer periphery of a workpiece using a flat rolling die that is reciprocatably supported on a rolling machine frame. a strain gauge disposed at at least one location on the surface of a support that is fixed to the rolling machine frame and supports a workpiece, or on the surface of a center shaft that rotatably supports the workpiece supported by the support; a strain amplifier that amplifies the gauge signal; and a level comparator that compares the input signal from the strain amplifier with a level set to an appropriate standard to determine abnormalities in the machining accuracy of teeth plastically machined on the outer periphery of the workpiece. A rolling machine characterized by comprising:

(Function) Oscillations generated in the workpiece during rolling processing, vibrations due to breakage of the rolling die, etc. are transmitted to the center shaft, and further transmitted from the center shaft to the support base, causing strain to the members of the center shaft and support base. cause a change in These strain changes are detected in real time by strain gauges. Furthermore, an abnormality in the support stand itself is similarly detected as long as it causes a change in strain in the member. The detected signal from the strain gauge is amplified by a strain amplifier and compared with a preset appropriate machining reference level by a level comparator, and abnormalities in machining accuracy of plastically machined teeth are determined. Ru.

(Example) Next, an example of the present invention will be described with reference to the drawings. In FIG. 7 showing a part of a rolling machine according to an embodiment of the present invention, upper flat rolling dies 1 are respectively supported on a rolling machine frame 10 in a reciprocating manner.
A and a lower flat rolling die 1b are arranged, and a workpiece W is held between them. The workpiece W is rotatably supported between the center shafts 3 and 4.
4 is a support stand 5 fixed on the rolling machine frame 10
is supported by

It is empirically known that when rolling is performed, the workpiece W rotates while swinging in the normal direction _L1 and the tangential direction _L2 . In rolling, the accuracy of rolling is maintained when the workpiece W is on a constant central axis, and it is clear that the accuracy of the rolling process is reduced if the workpiece W swings freely.

As an example, tooth pitch errors, which occur relatively frequently, will be described below.

Through experiments conducted by the present inventors, it has been found that when the amount of oscillation of the workpiece W in the tangential direction _L2 is large, the pitch error of the teeth formed on the outer periphery of the workpiece W becomes significantly worse.

The test results regarding the tangential swing of the workpiece and the tooth pitch error will be explained with reference to FIGS. 2 and 3. Second
The figure is a chart showing the oscillation waveform of the workpiece W in the tangential direction _L2 during rolling.

Looking at this waveform, the fine wave L ₂₁ and the coarse wave L _2nax overlap. A fine wave L ₂₁ indicates that the workpiece is oscillating finely with each tooth of the flat rolling die, and a coarse wave L _2nax indicates that the entire workpiece is slowly oscillating in the tangential direction. It shows that it is repeated. When measuring the period F of the rough waves, there is exactly one cycle of oscillation every time the workpiece rotates once.

The relationship between the fluctuation of this coarse tangential wave L _2nax and the tooth pitch error is shown in Figure 3, and a correlation was observed between the two. In addition, the tangential swing of the workpiece and the tooth pitch error are shown in Figure 4 during rolling processing.
It has been found that there is a relationship as explained in FIGS. 5-A to 5-I. Figure 4 shows the rough wave L _2nax movement or oscillation when the workpiece rotates once, and the workpiece oscillates ±L _2nax /2 with respect to the center line O-O of the center axis. It is assumed that The workpiece had eight teeth, and each tooth was rolled in the order of A to E.

In FIG. 5-A, the center line Q-Q of the workpiece W and the center line O-O of the center axis coincide. This is the state shown in A in FIG. 4, and the first tooth a is formed by the upper flat die 1a.

5-B corresponds to B in FIG. 4, with the flat die advanced by 1 pitch P. At this time, the center line Q-Q of the workpiece W is displaced slightly to the right (this is defined as a positive direction) with respect to the center line O-O of the center axis. The second tooth b is formed at a position advanced in the counter-rotational direction from the normal position (that is, the position when the tooth pitch is normal). At this time, a positive pitch error occurs between the first tooth a and the second tooth b.

FIG. 5-C corresponds to C in FIG. 4 when the flat die has advanced one pitch P further. At this time, the workpiece W
Since the center line Q-Q of is deviated by the maximum amount in the positive direction with respect to the center axis O-O, the third tooth c is formed at a position that is far advanced in the counter-rotation direction with respect to the normal position. At this time, a positive pitch error occurs between the second tooth b and the third tooth c.

FIG. 5-D corresponds to D in FIG. 4 when the flat die has advanced one pitch P further. At this time, the workpiece W
The tooth is slightly swung back, and the fourth tooth d is formed at a position closer to the normal position than the third tooth c.
A negative pitch error occurs between the tooth c and the fourth tooth d.

5-E corresponds to E in FIG. 4 when the flat die has advanced one pitch P further. At this time, since the center line Q-Q of the workpiece W coincides with the center axis O-O, the fifth tooth e is formed at a normal position. Fourth
A negative pitch error occurs between the tooth d and the fifth tooth e.

Since the workpiece W has rotated half a rotation, the first tooth a is processed by the opposing lower flat die 1b, but its forming position is the same as the original tooth position.

From then on, in Figure 5-F, the workpiece W swings to the left (minus direction), in Figure 5-G, the deflection in the negative direction reaches its maximum, and in Figure 5-H, it is slightly swayed back, and in Figure 5-I. In the figure, the workpiece rotates once and the same state is repeated.

As a result, teeth having positive and negative pitch errors as shown in FIG. 6 are formed on the outer periphery of the workpiece W. Here, we have seen how teeth are formed with the upper flat die 1a, but with the lower flat die 1b, tooth formation is performed with a 180° deviation from this, and the tooth pitch error is the same as in Figure 6. become. The relationship between the tangential vibration of the workpiece and the occurrence of tooth pitch error can be explained as above.

This invention applies the correlation between the swing of the workpiece and the tooth pitch error shown in Figure 3, and the accuracy of tooth machining (especially the tooth pitch accuracy) can be determined by detecting the swing of the workpiece. It is something that we try to do.

That is, as shown in FIG. 1 and FIG. 7, during rolling, the vibration that occurs in the workpiece W with respect to the rolling frame 10 is transmitted to the center shaft 3, and further to the center shaft 3.
is transmitted to the support base 5 via the support table 5, causing a change in strain on the surfaces of these members. In order to detect this strain, at least one strain gauge S ₁ , S ₂ is installed at at least one location on the non-rotating portion of the center shaft 3 or on the member surface of the support base 5 . The detected amount signals of the strain gauges S ₁ and S ₂ are amplified by a strain amplifier 11, and compared with a level set as an appropriate standard by a level comparator 13.

This level comparator 13 includes strain gauges S ₁ and S ₂
When the detected amount signal exceeds a certain value set in advance by the level setter 12, the pitch accuracy of the teeth that is correlated with it is determined to be abnormal, an external alarm is issued by the display 15, and the rolling machine is activated. It has functions such as stopping operation. In addition, to measure long-term changes, recorder 1
4 for automatic recording.

(Effects of the invention) As described above, the present invention uses a rolling machine that plastically forms a tooth profile on the outer periphery of a workpiece using a flat rolling die. By using strain gauges to detect changes in strain that occur on the surface of the center shaft or the surface of the support base to which motion is transmitted, abnormalities can be detected in real time. Therefore, it is possible to easily determine the quality of the machining accuracy of the workpiece, especially the tooth pitch error, in real time. The rolling machine of this invention constantly monitors changes in accuracy, so it is not only possible to detect long-term trends in accuracy deterioration, but also to detect abnormalities in real time during machining, even in the event of a sudden accident. It became possible.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the main parts of a rolling machine according to an embodiment of the present invention and an electric circuit connected thereto; Fig. 2 is a chart showing the tangential vibration waveform of a workpiece being rolled; Fig. 3 is a graph showing the test results for the tangential swing of the workpiece and tooth pitch error, Fig. 4 is a graph showing the swing of the rough wave L _2nax when the workpiece rotates once, and Fig. 5- Figures A to 5-I are sequential explanatory diagrams showing the relationship between the tangential swing of the workpiece and the tooth pitch error when the workpiece rotates once between rolling flat dies during rolling. FIG. 6 is an explanatory diagram showing the tooth pitch error on the outer periphery of the workpiece after machining, and FIG. 7 is a partial enlarged perspective view of the main part of the rolling machine shown in FIG. 1. 1a, 1b... Rolling flat die, 3, 4... Center shaft, 5... Support stand, 10... Rolling machine frame,
11...distortion amplifier, 13...level comparator,
L ₂ ...Tangential swing, S ₁ , S ₂ ...Strain gauge,
W...workpiece.

Claims (1)

[Scope of utility model registration request] In a rolling machine that plastically forms a tooth profile on the outer periphery of a workpiece using a rolling flat die supported reciprocally on the rolling machine frame, a support surface that is fixed to the rolling machine frame and supports the workpiece; or a strain gauge disposed at at least one location on the center axis surface that rotatably supports the workpiece supported by the support base, a strain amplifier that amplifies the signal of the strain gauge, and an input from the strain amplifier. A rolling machine comprising: a level comparator that compares the signal with a level set as an appropriate standard to determine abnormalities in the machining accuracy of the plastically worked teeth.