TW201525630A - Method for determining oil injection time of linear transmission element - Google Patents

Abstract

A method for determining oil injection time of linear transmission element, which comprises the following steps: intercepting physical signals of the linear transmission element by using a sensor, transforming the physical signals into characteristic values by algorithm, storing the characteristic values and establishing the relation between the characteristic values and time on the coordinate so as to form a characteristic curve and divide the transverse area into a plurality of time sections, calculating the characteristic values of the adjacent time sections so as to form a slope value and the sum of the slope values, and determining oil injection time. When the sum of the slope values is smaller that the ser value, that means there is no enough oil, contrarily, the oil is enough.

Description

Method for judging the timing of oiling of linear transmission components

The present invention relates to linear transmission components, and more particularly to a method of determining the timing of oil injection of linear transmission components.

The ball screw in the linear transmission component is mainly composed of a nut that is screwed through the free-rolling ball and the screw shaft, and uses the free-rolling ball to relatively slip the nut and the screw shaft, because of its excellent smoothness and Accuracy, so it is widely used in a variety of tools that require precision movement, so the lubrication of the spiral track inside the ball screw is particularly important. If the ball screw lacks lubrication for a long time, the friction between the nut and the screw may increase to accelerate the wear of the ball screw. Therefore, it is more important to judge the timing of the ball screw injection. To this end, the following is a list of patents that can be used to determine the timing of oiling.

Refer to Japanese Patent JPA_2004-347401, which is used to judge whether the lubrication of the bearing is sufficient. It mainly uses the accelerometer to sense the vibration signal of the bearing and converts it into a spectrum signal, and then determines the lubrication of the bearing by the defined threshold value. Is it enough to control the oil filling device to automatically fill the bearing? However, the patent must pre-establish a database to define the threshold value, and must simultaneously analyze the spectrum signal and establish the threshold with the database. The comparison of the values highlights the defect of judging the cost of the oil filling timing, and the patent case is based on the judgment of the timing of the oil filling of the bearing, and cannot be directly applied to the linear transmission component, especially Ball screw or ball spline.

Refer to Japanese patent JPA_1998-318261 for determining the lubrication of bearings. Whether it is sufficient, it is mainly to use the magnitude and period of the signal sensed by the sensor to judge whether the lubrication of the bearing is sufficient, so as to control the oil filling device to automatically fill the bearing. However, the patent has not been standardized. The magnitude of the signal and the length of the cycle make it difficult to implement, and the patented case is based on the timing of the oil injection timing of the bearing, and cannot be directly applied to the linear transmission component, especially the ball screw or the ball spline.

Therefore, how to develop a method for judging the timing of oil injection of a linear transmission component, which can simultaneously solve the above defects is the motivation for the development of the invention.

The object of the present invention is to provide a method for judging the timing of oil injection of a linear transmission component, which can accurately determine the timing of oil injection of a linear transmission component without pre-establishing a database for comparison, thereby reducing implementation cost and facilitating determination of linear transmission components. The timing of oiling.

Another object of the present invention is to provide a method for determining the timing of oiling of a linear transmission component, which can still determine the timing of oiling when the linear transmission component is rotated.

In order to achieve the foregoing objective, a method for determining a timing of oiling a linear transmission component according to the present invention includes: a signal extraction step: taking a sensor disposed on a linear transmission component to capture the linear transmission component The physical signal during the activation; the signal conversion step: converting each physical signal into a feature value by an algorithm; the feature value establishing storage step: establishing and storing each of the coordinates with the feature value as the vertical axis and the time as the horizontal axis The relationship between the eigenvalue and the time to form an eigenvalue variation curve, and the horizontal axis on the coordinate is divided into a plurality of time segments; the eigenvalue calculation step: calculating a slope by taking the eigenvalue corresponding to each adjacent time a value, and calculating a sum of each of the slope values in each of the time segments; a fueling determination step: determining whether the sum of the slope values in each of the time segments is less than a set value, and summing the slope values in the time segment When the value is less than the set value, it indicates that the oil film is insufficient. When the sum of the slope values in the time zone is greater than the set value, it indicates that the oil film is sufficient.

Preferably, a signal is further included between the signal extraction step and the signal conversion step. a processing step of processing the physical signal obtained in the signal extraction step to reduce the noise value contained in each physical signal, and outputting the processed physical signal for the signal conversion step to each of the physical The signal is converted into a feature value.

Preferably, the physical signal in the signal extraction step is for the linear transmission component The vibration signal generated during the rotation further includes a normalization step between the signal conversion step and the characteristic value establishing storage step for eliminating the difference of the vibration signals caused by the difference in the rotational speed of the linear transmission element.

Preferably, the physical signal in the signal extraction step is a pressure wave signal or a resistance signal generated during the operation of the linear transmission element.

Preferably, the feature values in the signal conversion step are Root Mean Square (RMS), Envelopment RMS, Wavelet, and Fourier Transform (FFT). .

Preferably, in the signal extraction step, the linear transmission component is a ball screw, and the sensor is disposed on a screw of the ball screw or on a screw of the ball screw.

Preferably, the physical signal in the signal extraction step is a vibration signal generated by the linear transmission component during the rotation, and further includes a normalization step between the feature value establishing storage step and the feature value calculation step. It is used to eliminate the difference of the vibration signals caused by the difference in the rotational speed of the linear transmission component.

The present invention has been described with reference to the preferred embodiments of the present invention in accordance with the accompanying drawings.

11‧‧‧Signal capture steps

12‧‧‧Signal conversion steps

13‧‧‧Characteristic value establishment storage steps

14‧‧‧Characteristic value calculation steps

15‧‧‧ Oil filling judgment steps

16‧‧‧Signal processing steps

17‧‧‧ formalization steps

21‧‧‧ Sensors

22‧‧‧Ball screw

221‧‧‧ nuts

222‧‧‧ screw

23‧‧‧ physical signals

30‧‧‧ coordinates

31‧‧‧First time section

32‧‧‧Second time section

33‧‧‧ third time section

34‧‧‧fourth time section

40, 41, 42, 43, 44, 45‧‧‧ eigenvalue curve

Figure 1 is a flow chart of a first embodiment of the present invention.

Fig. 2 is a side view showing the first embodiment of the present invention, showing a state in which the sensor is placed on the nut of the ball screw in the signal extracting step.

Figure 3 is a schematic view showing the first embodiment of the present invention, showing the state in which the physical signal captured in the signal capturing step is the vibration signal generated in the rotation of the ball screw.

Fig. 4 is a view showing the first embodiment of the present invention, showing a state in which the feature value change curve is established on the coordinates in the feature value establishing storage step.

Fig. 5 is a schematic view showing a first embodiment of the present invention, showing a state in which it is judged whether or not each time zone is required to perform an oiling operation in the oil filling judging step.

Figure 6 is a flow chart of a second embodiment of the present invention.

Figure 7 is a flow chart of a third embodiment of the present invention.

Figure 8 is a schematic view showing a third embodiment of the present invention, showing a state in which the physical signal captured in the signal capturing step is a vibration signal generated in the rotation of the ball screw.

Figure 9 is a schematic view showing a third embodiment of the present invention, showing a state in which a feature value change curve is established on a coordinate in the feature value establishing and storing step.

Figure 10 is a flow chart of a fourth embodiment of the present invention.

Figure 11 is a schematic view showing a fourth embodiment of the present invention, showing a state in which the physical signal captured in the signal capturing step is a vibration signal generated in the rotation of the ball screw.

Figure 12 is a schematic view showing a fourth embodiment of the present invention, showing a state in which a feature value change curve is established on a coordinate in the feature value establishment storing step.

Fig. 13 is a view showing a fourth embodiment of the present invention, showing a state in which a normalized characteristic value change curve is formed on the coordinate in the normalization step, and a state in which it is determined whether or not each time zone needs to be oil-filled.

It should be noted that, in the following embodiments, the linear transmission component is a ball screw, and may of course be a ball spline, but is not limited thereto.

Referring to FIG. 1 , a method for determining a timing of oiling a linear transmission component according to a first embodiment of the present invention is mainly provided by a signal extraction step 11 , a signal conversion step 12 , and a feature value establishment storage step 13 . And a characteristic value calculation step 14 and an oil filling determination step 15, wherein: as shown in FIGS. 2 and 3, the signal extraction step 11: taking a sensor 21 on the ball screw 22 for continuous The physical signal 23 of the ball screw 22 is in operation. In this embodiment, the sensor 21 is disposed on the nut 221 of the ball screw 22, and may of course be disposed on the screw 222 of the ball screw 22. The physical signal 23 is a vibration signal generated by the ball screw 22 at a rotation speed of 3000 revolutions per minute (rpm), and may of course be a pressure wave signal or a resistance signal generated during the operation of the ball screw 22.

The signal conversion step 12: converting each physical signal 23 into a feature value by an algorithm; in this embodiment, the feature value is a Root Mean Square (RMS), and may of course be an envelope root mean square (Envelopment RMS), wavelet analysis (Wavelet), Fourier transform spectrum (FFT), the conversion equation is Where n is the number of data retrieved per x , x is the physical quantity corresponding to each data point, i = 1~ n .

Referring to FIG. 4, the feature value establishment storage step 13: establishing and storing the relationship between the feature values and time on the coordinates 30 whose feature values are the vertical axis and the time is the horizontal axis to form a feature value change curve 40. The horizontal axis on the coordinate 30 is divided into a plurality of time segments; in this embodiment, the horizontal axis of the coordinate 30 is divided into a first time segment 31 and a second time segment in units of 15 minutes. 32. A third time segment 33 and a fourth time segment 34.

The feature value calculation step 14: calculating a feature value corresponding to each adjacent time a slope value, and calculating a sum of each of the slope values in the first to fourth time segments 31, 32, 33, 34; for example, the second time segment 32 is one unit in one minute, and thus the second time The segment 32 has first to fifteenth units, and the slope value calculated by taking the feature value corresponding to each adjacent time refers to the feature value corresponding to the first unit and the feature value corresponding to the second unit. The slope value between the slope value, the feature value corresponding to the second unit, and the slope value corresponding to the third unit, the slope value corresponding to the third unit, and the slope between the feature values corresponding to the fourth unit The value is the slope value between the feature value corresponding to the fourteenth unit and the feature value corresponding to the fifteenth unit.

The oiling determination step 15: determining whether the sum of the slope values in each of the time segments is small In the set value, when the sum of the slope values in the time zone is less than the set value, it indicates that the oil film is insufficient, and when the sum of the slope values in the time zone is greater than the set value, it indicates that the oil film is sufficient; wherein the set value can be visually required. For the setting, as shown in FIG. 5, the sum of the slope values in the first time zone 31 (for example, 10) is greater than the set value (for example: 0), and the sum of the slope values in the second time zone 32 ( For example: 5) is also greater than the set value (for example: 0), which means that the oil film in the ball screw is sufficient, and no oiling operation is required; so that the sum of the slope values in the third time zone 33 (for example: 1) Although it is larger than the set value (for example, 0), the sum of the slope values is close to the set value, indicating that the oil film in the ball screw is sufficient, and the oil filling operation is not required, but the oil film is in a state of deterioration; The sum of the slope values in the time zone 34 (for example, -1) is smaller than the set value (for example, 0). At this time, it indicates that the oil film in the ball screw is insufficient, and the oil filling operation is required, and the time point for optimal oil filling can be set. In the third time zone 33 and the fourth time The junction of the segments 34.

It is worth mentioning that, in the oil filling determination step 15, when the lubrication is gradually insufficient, the slope of the change of the characteristic value change curve 40 is gradually slowed, and the slope is gradually slowed except for the previous paragraph, and the threshold is set. Or the slope change amount or slope from positive to negative can be used as a basis for judgment.

The above description is the main steps of the first embodiment of the present invention. The effects of the present invention are explained below.

Since the present invention judges the timing of oiling, there is no need to pre-build a database. To define the threshold value and compare it with the threshold value built by the database, and only need to judge the sum of the slope values in each time segment to compare with a single set value to determine the specific time segment. The inside is sufficient oil film, the oil film is declining, or the oil film is insufficient, and the optimal oiling timing is determined. Therefore, the present invention can accurately determine the oil filling timing of the ball screw without pre-establishing the database for comparison, thereby reducing the implementation cost. And it is convenient to realize the timing of oiling the ball screw.

Referring to FIG. 6, a judgment linear transmission according to a second embodiment of the present invention is provided. The method for loading the timing of the moving component is also composed of the signal extraction step 11, the signal conversion step 12, the feature value establishment storage step 13, the feature value calculation step 14, and the oil injection determination step 15, because the steps and functions are the same as The first embodiment is not described again. The second embodiment is different in that the signal extraction step 11 and the signal conversion step 12 further include a signal processing step 16 for processing the signal acquisition step. The physical signal obtained in step 11 is used to reduce the noise value contained in each physical signal, and output the processed physical signal for the signal conversion step to convert each physical signal into a characteristic value.

Referring to FIG. 7, a judgment linear transmission according to a third embodiment of the present invention is provided. The method for loading the timing of the moving component is also composed of the signal extraction step 11, the signal conversion step 12, the feature value establishment storage step 13, the feature value calculation step 14, and the oil injection determination step 15, because the steps and functions are the same as The first embodiment is not described again. The third embodiment is different in that the physical signal in the signal extraction step 11 is a vibration signal generated during the rotation of the ball screw, and the ball screw is rotating. During the change of the rotational speed, a normalization step 17 is further included between the signal conversion step 12 and the characteristic value establishing storage step 13 for eliminating the difference in the vibration signal caused by the difference in the rotational speed of the ball screw. More specifically, the signal extraction step 11: the sensor is disposed on the nut of the ball screw to continuously capture the physical signal of the ball screw in the operation; see Figure 8, the present In an embodiment, The physical signal 23 is a vibration signal generated by the ball screw at a rotation speed of 1000, 2000, 3000 revolutions per minute (rpm), and the ball screw is 1000 revolutions per minute (rpm) in the first time zone 31. Rotate, at a second time zone 32, at 2000 revolutions per minute (rpm), and at a third time zone 33 at 3000 revolutions per minute (rpm).

The signal conversion step 12: converting each physical signal 23 into a feature by an algorithm In the embodiment, the feature value is a Root Mean Square (RMS), and the manner in which the physical signal 23 is converted into a feature value is the same as that in the first embodiment, and therefore will not be described again.

The normalizing step 17 is for eliminating the difference of the vibration signals caused by the different rotation speeds of the ball screws, that is, the characteristics of converting the physical signals 23 into the signal conversion step 12 when the rotation speed changes and is not repeated. Value-speed correction factor, the speed correction factor is N _RMS = (RMS _{n -} RMS ₀ ) / RMS ₀ ; where RMS _n is the current characteristic value of the screw (for example: RMS value after 15 minutes of screw operation), RMS ₀ is Is the initial characteristic value of the screw.

Example: RMS ₀ = 0.9 (the RMS value of the vibration signal measured by the screw after oil filling); RMS _n = 1.8 (the RMS value of the measured vibration signal after the screw has been running for a while); Therefore, N _rms = (1.8-0.9) / 0.9 = 1, to achieve the effect of normalization.

Referring to FIG. 9, the feature value is established and stored in step 13: on the vertical axis of the feature value, The relationship between the feature value and the time after each of the normalization steps 17 is established and stored on the coordinates 30 of the horizontal axis to form a feature value change curve 41.

The feature value calculation step 14 and the oil filling determination step 15 are the same as the first embodiment. Therefore, it will not be repeated.

Accordingly, in the third embodiment of the present invention, the database is not required to be built in advance. Yes, the oil injection timing of the ball screw can be accurately judged, thereby reducing the implementation cost and facilitating the judgment of the oil injection timing of the ball screw, and the fuel injection timing can be judged even when the ball screw is rotated.

Referring to FIG. 10, a determination linearity provided by the fourth embodiment of the present invention is provided. The method for timing the oiling of the transmission component is also composed of the signal extraction step 11, the signal conversion step 12, the feature value establishment storage step 13, the feature value calculation step 14, and the oil injection determination step 15, because the steps and functions are the same as The first embodiment is not described again. The fourth embodiment is different in that the physical signal in the signal extraction step 11 is a vibration signal generated during the rotation of the ball screw, and the ball screw is rotating. When the change in the rotational speed is generated, a further normalization step 17 is included between the characteristic value establishing storage step 13 and the characteristic value calculating step 14 for eliminating the difference in the vibration signal caused by the difference in the rotational speed of the ball screw. More specifically: the signal extraction step 11: the sensor is disposed on the nut of the ball screw to continuously capture the physical signal of the ball screw in the operation; see Figure 11, the present In the embodiment, the physical signal 23 is a vibration signal generated by the ball screw at a rotation speed of 1000, 2000, 3000 revolutions per minute (rpm), and the ball screw is in the first and second time sections 31, 32. Rotate at 1000 revolutions per minute (rpm), rotate at 2000 revolutions per minute (rpm) in the third time zone 33, and rotate at 3000 revolutions per minute (rpm) in the fourth time zone 34.

The signal conversion step 12: converting each physical signal 23 into a feature by an algorithm In the embodiment, the feature value is a Root Mean Square (RMS), and the manner in which the physical signal 23 is converted into a feature value is the same as that in the first embodiment, and therefore will not be described again.

Referring to FIG. 12, the feature value is established and stored in step 13: on the vertical axis of the feature value, The relationship between the feature values and time is established and stored on the coordinates 30 of the horizontal axis to form a characteristic value change curve, and the horizontal axis of the coordinate is divided into the first time segment 31 by 15 minutes. a second time segment 32, a third time segment 33, and a fourth time segment 34, wherein the eigenvalue variation curve 42 of the first and second time segments 31, 32 is the ball screw at the 0th to The 30 minutes is rotated at 1000 revolutions per minute (rpm), and the characteristic value change curve 43 in the third time section 33 is that the ball screw rotates at 2000 revolutions per minute (rpm) at the 30th to 45th minute. State, in the first The characteristic value change curve 44 of the four-time period 34 is a state in which the ball screw is rotated at 3000 revolutions per minute (rpm) at the 45th to 60th minute.

The normalization step 17 is for eliminating the vibration caused by the difference in the rotation speed of the ball screw The difference of the motion signal, that is, when the rotation speed changes and does not repeat, the eigenvalue change curve is given a rotation speed correction factor, so that a normalized eigenvalue change curve 45 is formed on the coordinate 30, and its state is as shown in FIG. Shown. In this embodiment, the manner of the normalization step 17 is the same as that of the third embodiment, and therefore will not be described again.

The feature value calculation step 14 and the oil injection determination step 15 are the same as those of the first embodiment, and therefore will not be described again.

Accordingly, in the fourth embodiment of the present invention, the oil injection timing of the ball screw can be accurately determined without the need to pre-establish the database for comparison, thereby reducing the implementation cost and facilitating the judgment of the oil injection timing of the ball screw. When the ball screw is rotated, the timing of the oiling timing can still be judged.

In the above, the above embodiments and the illustrations are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equal variations and modifications made by the scope of the patent application of the present invention are It should be within the scope of the patent of the present invention.

11‧‧‧Signal capture steps

12‧‧‧Signal conversion steps

13‧‧‧Characteristic value establishment storage steps

14‧‧‧Characteristic value calculation steps

15‧‧‧ Oil filling judgment steps

Claims (7)

A method for determining a timing of oiling a linear transmission component, comprising: a signal extraction step: taking a sensor disposed on a linear transmission component to capture a physical signal of the linear transmission component during operation; and a signal conversion step: by calculating The method converts each physical signal into a feature value; the feature value is established and stored: the relationship between the feature value and time is established and stored on the coordinate whose feature value is the vertical axis and the time is the horizontal axis to form a characteristic value curve. And dividing the horizontal axis on the coordinate into a plurality of time segments; the eigenvalue calculation step: calculating a slope value by taking the eigenvalue corresponding to each adjacent time, and calculating each of the time segments The sum of the slope values; the oil filling determining step: determining whether the sum of the slope values in each of the time segments is less than a set value, and when the sum of the slope values in the time segment is less than the set value, indicating that the oil film is insufficient, when the time zone is When the sum of the slope values in the segment is greater than the set value, it indicates that the oil film is sufficient. The method for determining the timing of oiling the linear transmission component according to the first aspect of the invention, wherein the signal extraction step and the signal conversion step further comprise a signal processing step for processing the signal acquisition step. The physical signal is used to reduce the noise value contained in each physical signal, and output the processed physical signal for the signal conversion step to convert each physical signal into a characteristic value. The method for determining the timing of oiling the linear transmission component according to claim 1, wherein the physical signal in the signal extraction step is a vibration signal generated during the rotation of the linear transmission component, and in the signal conversion step There is further included a normalization step between the step of establishing the storage of the characteristic values, which is used to eliminate the difference of the vibration signals caused by the difference in the rotational speed of the linear transmission elements. The method for determining the timing of oiling the linear transmission component according to the first aspect of the patent application, wherein the physical signal in the signal extraction step is a pressure wave signal or a resistance signal generated during the actuation of the linear transmission component. The method for determining the timing of oiling the linear transmission component according to the first aspect of the patent application, wherein the characteristic value in the signal conversion step is root mean square (RMS), envelope root mean square (Envelopment RMS), Wavelet analysis (Wavelet), Fourier transform (FFT, Fast Fourier Transform). The method for determining the timing of oiling the linear transmission component according to the first aspect of the patent application, wherein in the signal extraction step, the linear transmission component is a ball screw, and the sensor is disposed on a nut of the ball screw or On the screw of the ball screw. The method for determining the timing of oiling the linear transmission component according to the first aspect of the patent application, wherein the physical signal in the signal extraction step is a vibration signal generated during the rotation of the linear transmission component, and the characteristic value is established. Further, a step of normalizing between the storing step and the characteristic value calculating step is performed to eliminate the difference of the vibration signals caused by the difference in the rotational speed of the linear transmission element.