JP7075608B1 - Gear accuracy evaluation method and evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear accuracy evaluation method capable of easily estimating the cause of noise generation such as ghost noise. SOLUTION: This is a gear accuracy evaluation method for evaluating accuracy based on deviation data of each tooth of a gear measured by a gear measuring machine. The relationship between the deviation data of two adjacent teeth on the base circle of the gear is obtained by the mutual correlation function, and the step of extracting the periodic deviation left on the tooth surface across the two teeth and the period. A step of creating evaluation data of the relationship between the rotation phase of the gear and the periodic deviation by sequentially performing the step of extracting the deviation with respect to the tooth in the direction in which the rotation phase of the gear advances. Be prepared. [Selection diagram] Fig. 3

Description

The present invention relates to an evaluation method and an evaluation device for gear accuracy.

Conventionally, for accuracy evaluation of cylindrical gears, the shape deviation of the target gear is measured using a gear measuring machine evaluated according to the JIS B 1757-1 (2012) standard, and JIS B 1702-1: 2016 (cylinder). Gear-Accuracy grades Part 1: Definitions and tolerances for errors related to the tooth surface of gears) have been used to evaluate tooth profile, streaks, and pitch deviations according to the accuracy grades.

Actually, by evaluating the single pitch error, the cumulative pitch error, the total tooth profile error, the total tooth streak error, etc. according to the reference circle diameter and the size of the module, the accuracy grades have been classified. This JIS B 1702-1 is a Japanese Industrial Standard created based on the international standard ISO 1328-1 issued in 2013, but it is based on the abolished standard JIS B 1702: 1976 issued in 1976. It is a standard that has been revised at the same time, and although the accuracy grade has been revised and the definition of words has been changed in order to comply with ISO, no fundamental changes have been made.

Japanese Unexamined Patent Publication No. 62-282216

Normally, when a pair of gears meshes, meshing vibration and its harmonic components determined by the shaft rotation frequency and the number of teeth are generated, but components other than these assumed frequencies may be generated, which is called ghost noise. It is difficult to identify the cause. If a transmission with low noise and low vibration cannot be realized even with a high-precision gear pair, such unexpected factors may occur. In other words, it means that evaluation items other than the accuracy grade are necessary to eliminate these factors and construct a quiet transmission, and the evaluation accuracy items specified by the current JIS are not sufficient. be. It is knowledgeable to compare the raw waveforms of pitch error, tooth profile error, and tooth streak error of all teeth on a gear accuracy inspection result sheet arranged in numerical order as a graph, and to extract factors that are factors other than meshing vibration and its harmonic components. It is difficult without experience. In this case, as accuracy evaluation items, the inclination (tooth profile gradient error, tooth trace inclination error) and amplitude (total tooth profile error, tooth profile error, all tooth trace error, tooth) from the graph of tooth profile error and tooth trace error of each tooth. The streak shape error) was derived, and the maximum value was used to evaluate the accuracy grade from the results of all teeth. These evaluation indexes determine the accuracy grade from the maximum error of the gear shape, and only evaluate the worst value of a certain tooth as a feature amount. Since the gear is actually used while rotating, each tooth arranged on the circumference meshes with the mating gear in order, but the deviation measured individually for each tooth is arranged in order, and the gear There was no way to evaluate the deviation from a bird's-eye view. Therefore, it has not been possible to solve the problem of evaluating the shape deviation leading to vibration from the raw waveform of the deviation data of each tooth measured as an error of the geometric shape.

An object to be solved by the present invention is to provide a gear accuracy evaluation method and an evaluation device that can easily estimate the cause of noise generation such as ghost noise.

The gear accuracy evaluation method of the present invention is a gear accuracy evaluation method for evaluating the accuracy based on the deviation data of each tooth of the gear measured by the gear measuring machine, and is arranged next to each other on the base circle of the gear. The relationship between the deviation data of the two teeth is obtained by the mutual correlation function, and the step of extracting the periodic deviation left on the tooth surface straddling the two teeth and the periodic deviation are extracted. The steps are sequentially performed on the teeth in the direction in which the rotation phase of the gear advances, thereby comprising a step of creating evaluation data of the relationship between the rotation phase of the gear and the periodic deviation.

The gear accuracy evaluation device of the present invention is a gear accuracy evaluation device that evaluates the accuracy based on the deviation data of each tooth of the gear measured by the gear measuring machine, and is arranged next to each other on the base circle of the gear. The relationship between the deviation data of the two teeth is obtained by the mutual correlation function, and the deviation extraction unit that extracts the periodic deviation left on the tooth surface straddling the two teeth and the period by the deviation extraction unit. Deviation is extracted in order for the teeth in the direction in which the rotational phase of the gear advances, thereby creating evaluation data for the relationship between the rotational phase of the gear and the periodic deviation. It has a creation unit.

According to the present invention, the shape deviation of the gear measured by the gear measuring machine is not evaluated individually, but the periodicity between the deviations left in the adjacent teeth changing according to the rotation phase is a mutual correlation function. By arranging them in the order in which the rotation phase of the gear advances, it is possible to observe and evaluate the shape deviation of the entire gear from a bird's-eye view, which has been difficult until now, such as ghost noise. The cause of noise can be easily estimated.

It is explanatory drawing of a gear. It is a block diagram of the evaluation apparatus which shows one Embodiment of this invention. It is a flowchart of the evaluation method of a gear accuracy. It is a graph of the deviation data of one tooth of a gear measured by a gear measuring machine. It is a graph of the deviation data to which the Gaussian filter is applied. It is a graph which shows the evaluation data of the relationship between the rotation phase and the periodic deviation in the case of a good product. It is a graph which shows the evaluation data of the relationship between the rotation phase and the periodic deviation in the case of a defective product.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the gear 10. The gear 10 includes a plurality of teeth 12 provided side by side on the base circle 11. Then, the deviation of the tooth profile, the tooth streak, etc. of each tooth 12 is measured by the gear measuring machine.

Further, FIG. 2 shows a gear accuracy evaluation device 20. The evaluation device 20 is configured by, for example, a computer. The evaluation device 20 acquires deviation data of each tooth 12 measured by the gear measuring machine 21, and determines the relationship between the deviation data such as the tooth profile deviation and the tooth streak deviation of each tooth 12 from the acquired deviation data. By arranging and visualizing the 10s in the order in which they engage, the deviation that causes vibration can be evaluated from a bird's-eye view of the entire gear 10.

The evaluation device 20 includes a Gaussian filter 22, a deviation extraction unit 23, and an evaluation data creation unit 24. The Gaussian filter 22 extracts deviation data of a predetermined frequency component from the deviation data of the teeth 12 of the gear 10 measured by the gear measuring machine 21. The deviation extraction unit 23 obtains the relationship between the deviation data of the two teeth 12 arranged adjacent to each other on the basic circle 11 of the gear 10 by a cross-correlation function, and the period left on the tooth surface straddling the two teeth 12. Deviation. The evaluation data creation unit 24 periodically extracts the deviation by the deviation extraction unit 23 with respect to the teeth 12 in the direction in which the rotation phase of the gear 10 advances. Create evaluation data of the relationship with various deviations. The evaluation data is, for example, a graph.

An output unit 25 that outputs evaluation data is connected to the evaluation device 20. The output unit 25 includes a display, a printer, and the like. The output unit 25 may be a part of the evaluation device 20.

Next, the method of evaluating the gear accuracy will be described with reference to the flowchart of FIG.

The evaluation device 20 acquires deviation data of each tooth 12 of the gear 10 measured by the gear measuring machine 21 (step S1). FIG. 4 shows the deviation data of one tooth 12.

The evaluation device 20 applies the Gaussian filter 22 to the acquired deviation data of each tooth 12, and extracts the deviation data of the frequency component of interest from the deviation left on the tooth surface of the tooth 12 by this filtering process. (Step S2). For example, the roughness data related to the surface texture has a short period and has a small effect on vibration, so it is removed by this filtering process, and the waviness component left on the tooth surface by the tooth grind finishing process is extracted. .. Furthermore, since the DC component does not contribute to vibration, it is removed from the original deviation data. FIG. 5 shows the deviation data extracted by the filtering process.

Then, by the deviation extraction unit of the evaluation device 20, the relationship between the deviation data (x (t) and y (t)) of the two teeth 12 arranged next to each other on the basic circle 11 of the gear 10 is set to the next number 1. It is obtained by the formula of the cross-correlation function (Rxy), and the periodic deviation left on the tooth surface straddling the two teeth 12 is extracted (step S3).

The procedure for obtaining the relationship between the deviation data (x (t) and y (t)) of two side-by-side teeth 12 by the formula of the cross-correlation function is sequentially performed for the tooth 12 in the direction in which the rotation phase of the gear 10 advances. By doing so (step S4), the evaluation data creating unit 24 of the evaluation device 20 creates evaluation data of the relationship between the rotational phases arranged in the order of meshing and the periodic deviation (step S5).

The evaluation data is created, for example, as a graph shown in FIG. 6 or 7, and is displayed on the display of the output unit 25 or printed out by a printer.

Then, when the finishing process of the gear 10 is appropriate and the adjacent teeth 12 have the same deviation, as shown in FIG. 6, the meshing vibration and the vibration mainly composed of the harmonic component thereof are generated, and in this case, the vibration is generated. The relationship between the rotational phase and the periodic deviation takes a large value at the position where the shift amount on the horizontal axis is 0, and decreases at the position where the shift amount is other than that. No significant change occurs in the direction of the rotation phase, which is the vertical axis, at positions with the same shift amount.

On the other hand, the gear 10 is poorly finished and ghost noise or the like is generated. Since the gear 10 is processed in an improper setting, it is left on the tooth surface as shown in FIG. 7. The machined marks will be left as an unusual cycle (FIG. 6). It is difficult to confirm the waveform left on these tooth surfaces by itself, but by creating a graph of the relationship between the rotational phase and the periodic deviation, the special periodicity can be easily confirmed visually. become.

As described above, according to the present embodiment, the shape deviation of the gear 10 measured by the gear measuring machine 21 is not evaluated individually, but the deviation left in the adjacent teeth 12 changing according to the rotation phase. By extracting the periodicity between them by a mutual correlation function and arranging them in the order in which the rotational phase of the gear 10 advances, it is possible to observe and evaluate the overall shape deviation of the gear 10 from a bird's-eye view. It is possible to easily estimate the cause of noise generation such as ghost noise, which was difficult to achieve.

10 Gear 11 Basic circle 12 Teeth 20 Evaluation device 21 Gear measuring machine 22 Gaussian filter 23 Deviation extraction unit 24 Evaluation data creation unit

Claims (4)

It is a gear accuracy evaluation method that evaluates the accuracy based on the deviation data of each tooth of the gear measured by the gear measuring machine.
The step of finding the relationship between the deviation data of two teeth arranged adjacent to each other on the base circle of the gear by a cross-correlation function and extracting the periodic deviation left on the tooth surface straddling the two teeth. When,
By sequentially performing the step of extracting the periodic deviation with respect to the tooth in the direction in which the rotation phase of the gear advances, evaluation data of the relationship between the rotation phase of the gear and the periodic deviation is created. Steps to do and
A method for evaluating gear accuracy. Prior to the step of extracting the periodic deviation, a step of applying a Gaussian filter to the deviation data of the teeth of the gear measured by the gear measuring machine and extracting the deviation data of a predetermined frequency component is performed. The method for evaluating gear accuracy according to claim 1, wherein the method is provided. It is a gear accuracy evaluation device that evaluates the accuracy based on the deviation data of each tooth of the gear measured by the gear measuring machine.
The relationship between the deviation data of two teeth arranged next to each other on the base circle of the gear is obtained by a cross-correlation function, and the deviation that extracts the periodic deviation left on the tooth surface straddling the two teeth. Extractor and
Evaluation data of the relationship between the rotation phase of the gear and the periodic deviation is performed by sequentially extracting the periodic deviation by the deviation extraction unit for the teeth in the direction in which the rotation phase of the gear advances. An evaluation device for gear accuracy, characterized in that it is equipped with an evaluation data creation unit. The gear accuracy evaluation device according to claim 3, further comprising a Gaussian filter that extracts deviation data of a predetermined frequency component from deviation data of the teeth of the gear measured by the gear measuring machine.

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