JP2009190096A - Method and device for machining gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend a service life of a machining tool concerning machining technology such as shaving technology for finishing a tooth surface of a gear. <P>SOLUTION: This machining method for a gear to be machined for rotating the machining tool by meshing it with the gear and finishing the tooth surface of the gear includes: a detection process for detecting the vibration caused by meshing of the machining tool with the gear; an analysis process for analyzing frequency characteristics of the vibration detected in the detection process; and a setting process for setting rotational speed of the machining tool based on the results of the analysis in the analysis process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a processing technique such as a shaving technique for finishing a tooth surface of a gear.

  Generally, a gear is finished with a tooth surface after gear cutting. A typical example is shaving. In the shaving process, the work gear is engaged with a shaving cutter and rotated, and the tooth surface is finely cut to perform a finishing process (Patent Document 1). A processing tool such as a shaving cutter is a consumable that is worn by use, and from the viewpoint of cost, it is desirable that the working tool has a longer useful life.

JP 2002-1616 A

  However, even with the same processing tool, the service life may differ depending on the processing machine such as a shaving machine used in combination, the gear to be cut, and the like, and the life may be exhausted at an early stage.

  An object of the present invention is to extend the service life of a machining tool.

  According to the present invention, in a gear machining method in which a machining tool is rotated by meshing with a work gear, and the tooth surface of the work gear is finished, the work tool and the work gear are meshed. A detection step for detecting the vibration generated by the analysis step, an analysis step for analyzing the frequency characteristics of the vibration detected in the detection step, a setting step for setting the rotation speed of the processing tool based on the analysis result of the analysis step, A gear machining method characterized by comprising:

  The machining method of the present invention is based on the idea that the variation in the useful life of a machining tool is due to the vibration state during use, and the life of the machining tool is shortened when the machining tool is resonating during machining. I thought. According to the machining method of the present invention, the vibration is detected in the detection step, the frequency characteristic is analyzed in the analysis step, and the rotation speed of the machining tool is set. Thereby, it can process in the range in which the said processing tool does not resonate, and the lifetime of the said processing tool can be made longer.

  In the present invention, the detection step, the analysis step, and the setting step may be performed at least when the machining tool is replaced. By carrying out each of the above steps at the time of exchanging the processing tool, the service life of the processing tool can be extended more reliably.

  Further, according to the present invention, in the gear machining apparatus that rotates the work tool in mesh with the work gear, and finishes the tooth surface of the work gear, the drive means that rotationally drives the work tool; Detecting means for detecting vibration generated by meshing of the machining tool and the work gear, analyzing means for analyzing frequency characteristics of vibration detected by the detecting means, and rotation speed of the machining tool by the driving means There is provided a gear processing device characterized by comprising setting means for setting.

  The machining apparatus of the present invention is based on the idea that the variation in the useful life of a machining tool is due to the vibration state during use, and the life of the machining tool is shortened when the machining tool resonates during machining. I thought. According to the processing apparatus of the present invention, vibration is detected by the detection means, and the frequency characteristic is analyzed by the analysis means. Further, the rotational speed of the machining tool is set by the setting means. Thereby, it can process in the range in which the said processing tool does not resonate, and the lifetime of the said processing tool can be made longer.

  In the present invention, the drive means may include a main shaft portion connected to the processing tool and a bearing portion that rotatably supports the main shaft, and the detection means may be attached to the bearing portion. According to this configuration, it is possible to more accurately detect the vibration generated when the machining tool and the work gear mesh with each other.

  Moreover, in this invention, the display means which displays the analysis result of the said analysis means may further be provided, and the said setting means may be provided with the input means in which a user inputs the said rotational speed. According to this configuration, the user can set the rotation speed so that the machining tool does not resonate.

  In the present invention, the setting means determines whether the vibration level at a frequency defined by the number of teeth of the machining tool and the rotation speed of the machining tool exceeds a prescribed value based on the analysis result of the analysis means. Determination means for determining whether or not, and changing means for changing the rotational speed when the determination means determines that the vibration level exceeds the specified value. According to this configuration, the rotation speed at which the machining tool does not resonate can be automatically set.

  As described above, according to the present invention, the useful life of the machining tool can be further extended.

  FIG. 1 is a schematic explanatory diagram of a processing apparatus according to an embodiment of the present invention. The processing apparatus includes a shaving machine 100 and a control unit 200. The shaving machine 100 includes a cutter head 110 and a support part 120 for the work gear 122, and only the main part is shown in FIG. The basic configuration of the shaving machine 100 is the same as that of a known shaving machine.

  A motor 111 that rotationally drives the main shaft 114 is attached to the cutter head 110. The motor 111 is, for example, an AC motor. A sub shaft portion 112 is connected to the output shaft of the motor 111, and the sub shaft portion 112 is rotatably supported by the cutter head 110. A gear 113 is attached to the countershaft portion 112 and meshes with a gear 115 attached to the main shaft portion 114.

  The main shaft portion 114 is rotatably supported by the cutter head 110 by bearing portions 116 and 117. A shaving cutter 118 as a processing tool is concentrically connected to the tip end portion of the cutter head 110 so as to be detachable. When the motor 111 is rotationally driven, the driving force is transmitted to the main shaft portion 114 via the auxiliary shaft portion 112 and the gears 112 and 113, the main shaft portion 114 rotates, and the shaving cutter 118 rotates. The support unit 120 includes a pair of support tools 121, and the work gear 122 is rotatably supported by the pair of support tools 121.

  The shaving board 100 includes an elevating device (not shown) that raises and lowers the cutter head 110 in the Z direction (up and down direction) and a turning device (not shown) that turns the cutter head 110 around the Z direction.

  Thus, after the crossing angle between the shaving cutter 118 and the work gear 122 is set by the turning device, the shaving cutter 118 is rotated at a constant speed by the motor 111, and the cutter head 110 is lowered by the lifting device to perform the shaving. The tooth surface of the work gear 122 is finished by engaging and rotating the cutter 118 and the work gear 122.

  Next, in this embodiment, a vibration detection sensor 119 is provided in the bearing portion 117. The vibration detection sensor 119 detects vibration generated when the shaving cutter 118 and the work gear 122 mesh with each other. The vibration detection sensor 119 is, for example, a piezoelectric vibration pickup sensor. The arrangement site of the vibration detection sensor 119 is not limited to the bearing portion 117, and can be provided, for example, at an arbitrary site of the cutter head 110. However, the further away from the shaving cutter 118 and the work gear 122, the smaller the influence of noise. On the other hand, since the main shaft portion 114 and the shaving cutter 118 rotate, it is not easy to provide the vibration detection sensor 119. Therefore, if the vibration detection sensor 119 is provided in the bearing portion 117 of the main shaft portion 114 as in the present embodiment, vibration generated by the shaving cutter 118 and the work gear 122 meshing with each other is ensured while ensuring ease of arrangement. It can be detected more accurately.

  The control unit 200 includes a control unit 210, a display 220, an input device 230, a drive circuit 240, and an FFT (Fast Fourier Transform) analyzer 250, which are provided on an operation panel of the shaving board 100, for example. Can be provided.

  The control unit 210 includes a CPU 211, a ROM 212, a RAM 213, an I / F (interface) 214, and an HDD (hard disk drive) 215. The ROM 212, RAM 213, and HDD 215 may use other storage means.

  The CPU 211 executes programs stored in the ROM 212 and the HDD 215. The ROM 212 stores programs executed by the CPU 211 and fixed data. The RAM 213 temporarily stores the calculation result of the CPU 211 and the like. The I / F 214 is an interface between the display 220, the input device 230, the drive circuit 240, the FFT analyzer 250, and the CPU 211.

  In addition to the program executed by the CPU 211, the HDD 215 stores machining condition information 10 relating to machining conditions. The machining condition information 10 includes the type of the work gear 122, information on the shaving cutter 118 corresponding to the type, the rotational speed of the shaving cutter 118, and the machining time. In this embodiment, it is assumed that a plurality of shaving cutters 118 corresponding to the work gear 122 are prepared, and the information related to the shaving cutter 118 includes an ID for identifying each shaving cutter 118 and the number of teeth. It is. The rotation speed and processing time are defined for each shaving cutter 118.

  The display 220 is an image display device such as an LCD that displays various types of information. The input device 230 is used by the user to give various instructions to the control unit 200. For example, the input device 230 is a keyboard-type switch group that can be operated by the user. The drive circuit 240 is an electronic circuit that controls the motor 111 in response to a command from the CPU 211. When an AC motor is used as the motor 111, the drive circuit 240 is, for example, an inverter. The FFT analyzer 250 is a known device that receives a signal from the vibration detection sensor 119 and analyzes its frequency characteristic, and calculates and outputs a vibration level (spectrum) -frequency characteristic.

  In this embodiment, the FFT analyzer 250 is provided separately from the control unit 210. However, the control unit 210 may receive a signal from the vibration detection sensor 119 and the CPU 211 may analyze the frequency characteristic. Good. In this case, the analysis program is stored in the HDD 215 and is executed by the CPU 211.

  The control unit 210 controls the above-described lifting device (not shown) that lifts and lowers the cutter head 110 in the Z direction.

  Next, operation | movement of the processing apparatus of this embodiment is demonstrated. FIG. 2 is a flowchart showing an example of processing executed by the CPU 211, and particularly shows processing when shaving processing is executed.

  In S1, initial setting is performed. Here, the input of the ID of the shaving cutter 118 used for machining and the type of the gear 122 to be shaved is accepted. The user inputs the type of the work gear 122 and the ID of the shaving cutter 118 through the input device 230. In S2, the machining condition information 10 is read from the HDD 215, and the rotation speed and machining time set in the type of the work gear 122 and the ID of the shaving cutter 118 set in S1 are acquired and set.

  In S <b> 3, it is determined whether or not the user has instructed the machining start via the input device 230. If the start of processing is instructed, the process proceeds to S4, and if not, the instruction from the user is awaited. In S4, the motor 111 is driven, and the shaving cutter 118 is rotated at a constant speed by the rotation speed read in S2. Subsequently, the cutter head 110 is lowered by an elevating device (not shown), and the cutter head 110 is lowered to a position where the shaving cutter 118 and the work gear 122 mesh with each other. The shaving cutter 118 is rotated at a constant speed by the rotation speed read in S2, and the work gear 122 is engaged with the shaving cutter 118, and the tooth surface is finely cut.

  In S5, it is determined whether or not the processing is finished. When the processing time read in S2 has elapsed, it is determined that the processing has been completed. If applicable, the process proceeds to S6, and if not applicable, the processing is continued. In S <b> 6, the cutter head 110 is lifted by an elevator device (not shown), and the shaving cutter 118 is retracted from the work gear 122. Further, the motor 111 is stopped and the rotation of the shaving cutter 118 is stopped. Thus, one unit of processing is completed. Thereafter, the machining of another work gear 122 is started.

  Next, the setting of the rotation speed of the shaving cutter 118 will be described. Here, the case where it sets by a user's input operation and the case where CPU211 sets automatically are demonstrated. Either of these may be set by the user, or only one of them may be possible. First, the former will be described. FIG. 3 is a flowchart showing an example of processing executed by the CPU 211, and particularly shows processing related to setting of the rotation speed of the shaving cutter 118.

  The processes of S11 and S12 are performed in parallel with the execution of the shaving process shown in FIG. First, in S11, it is determined whether or not measurement is started. Specifically, it is determined whether or not sampling by the FFT analyzer 250 is started for the signal from the vibration detection sensor 119. The measurement start timing is set, for example, slightly before the shaving cutter 118 meshes with the work gear 122 by the process of S4 described above. If it is determined that the measurement is started, the process proceeds to S12, and if not, the process waits.

  In S12, the FFT analyzer 250 is instructed to start measurement. As a result, the FFT analyzer 250 acquires and stores the signal from the vibration detection sensor 119 for a certain period of time. The time (period) during which the FFT analyzer 250 acquires a signal is at least a part of the time during which the shaving cutter 118 and the work gear 122 are engaged and the machining is actually performed. The FFT analyzer 250 performs frequency analysis after obtaining a signal for a certain time from the vibration detection sensor 119.

In S13, the frequency analysis result is acquired from the FFT analyzer 250. In S14, the acquired frequency analysis result is displayed on the display 220. FIG. 5A shows an example of the frequency analysis result displayed on the display 220. In the figure, the horizontal axis represents frequency and the vertical axis represents vibration level. A line L1 indicates a theoretical frequency generated when the shaving cutter 118 and the work gear 122 mesh with each other, and is calculated and displayed by the CPU 211. This theoretical frequency is calculated by the following equation, where X (rpm) is the rotational speed of the shaving cutter 118 and n is the number of teeth of the shaving cutter 118.
(Theoretical frequency: Hz) = X / 60 × n
Among the frequency analysis results displayed on the display 220, the user examines whether or not to change the rotational speed of the shaving cutter 118, particularly by looking at the vibration level at the theoretical frequency. That is, when the vibration level at the theoretical frequency is high, it is considered that the shaving cutter 118 resonates with other elements of the shaving board 100, such as the main shaft 114. If such a resonance is left unattended, it is considered that the shaving cutter 118 is damaged and its life is shortened. In such a case, the user can avoid the occurrence of resonance by changing the rotation speed of the shaving cutter 118.

  Returning to FIG. 3, in S <b> 15, it is determined whether or not the user has instructed to update the rotation speed of the shaving cutter 118 via the input device 230. If applicable, the process proceeds to S16, and if not applicable, one unit of processing is terminated. In S <b> 16, an input of a new rotation speed by the user via the input device 230 is accepted. The user calculates and inputs a new rotation speed in accordance with the frequency having a low vibration level among the frequency analysis results displayed on the display 220. However, since the rotational speed of the shaving cutter 118 is limited by the characteristics of the shaving cutter 118 and the work gear 122, production efficiency, and the like, for example, it is selected within a range of about ± 50 rotations of the initial rotational speed. Become.

  In S17, the rotation speed received in S16 is set. In the case of this embodiment, it sets by updating the content of the processing condition information 10. Specifically, in the machining condition information 10, the type of the work gear 122 used this time and the rotational speed corresponding to the shaving cutter 118 are changed to the rotational speed accepted in S16 and stored. Thereafter, when the same kind of the work gear 122 and the same shaving cutter 118 are used, the changed rotational speed is adopted.

  FIG. 5B is a diagram illustrating a frequency analysis result of vibration when processing is performed by changing the rotation speed of the shaving cutter 118 in the example in which the frequency analysis result is illustrated in FIG. The work gear 122 is of the same type, but uses another work gear 122 that has not been finished. The same shaving cutter 118 is used, and only the rotation speed is different.

  In FIG. 5B, a line L1 indicates a theoretical frequency generated when the shaving cutter 118 and the work gear 122 mesh with each other, and the rotational speed of the shaving cutter 118 is changed. I understand that In FIG. 5B, the vibration level at the frequency of the line L1 is smaller than the vibration level at the frequency of the line L1 in FIG. 5A, and the line L1 in FIG. With respect to the frequency of 400 Hz, it can be seen from the analysis result of FIG. 5B that the vibration level is smaller than in the case of FIG.

  That is, at the rotational speed of the shaving cutter 118 at the time of processing in the example of FIG. 5A, the shaving cutter 118 and related elements resonate, and the rotation of the shaving cutter 118 at the time of processing in the example of FIG. In speed it can be seen that this has been resolved.

  Next, a case where the rotational speed of the shaving cutter 118 is automatically set will be described with reference to FIG. In FIG. 4, the processing from S11 to S13 is the same as the processing from S11 to S13 in FIG.

  In S21, it is determined whether or not the vibration level of the theoretical frequency generated by the meshing of the shaving cutter 118 and the work gear 122 described above exceeds a specified value. The vibration level of the theoretical frequency is specified by acquiring the vibration level at the frequency calculated by the above formula among the frequency analysis results. In the example of FIG. 5A, the vibration level is on the line L1. The specified value is set in advance by the user based on, for example, past experimental results. In FIG. 5A, a line L2 shows an example of a specified value. If the theoretical vibration level of the frequency exceeds the specified value, the process proceeds to S22, and if not, one unit of processing is terminated.

  In S22, the rotational speed of the shaving cutter 118 is automatically changed. The rotation speed after the change is changed to, for example, a rotation speed at which the vibration level is the lowest within a certain rotation speed range. The range of the rotation speed can be set in advance by the user. For example, if the rotation speed range set by the user is ± 50 rpm and the number of teeth of the shaving cutter 118 is n, the frequency is ± (50/60 × n) Hz when converted to frequency. Therefore, in the example of FIG. 5A, the frequency at which the vibration level becomes the lowest value within the range of ± (50/60 × n) Hz with the line L1 as the center is specified, and the back calculation is performed from the specified frequency. To obtain the rotation speed. In S22, the CPU 211 performs such a calculation, whereby a more preferable changed rotation speed can be calculated.

  In S23, the rotation speed changed in S22 is set. In the case of this embodiment, it sets by updating the content of the processing condition information 10. Specifically, in the machining condition information 10, the type of the work gear 122 used this time and the rotational speed corresponding to the shaving cutter 118 are changed to the rotational speed accepted in S16 and stored. Thereafter, when the same kind of the work gear 122 and the same shaving cutter 118 are used, the changed rotational speed is adopted.

  As described above, the present embodiment is based on the idea that the variation in the service life of the shaving cutter 118 is caused by the vibration state at the time of use, and the shaving cutter 118 resonates with other elements during the shaving process. In some cases, the lifetime is considered to be shortened. In the present embodiment, the vibration generated when the shaving cutter 118 and the work gear 122 mesh with each other is detected, the frequency characteristics thereof are analyzed, and the rotational speed of the shaving cutter 118 is set. Thereby, shaving processing can be performed within a range where the shaving cutter 118 does not resonate, and the service life of the shaving cutter 118 can be further extended. Further, the life of other elements that can cause resonance with the shaving cutter 118, such as the main shaft portion 114 and the bearing portions 116 and 117, can be extended by avoiding resonance.

  The setting timing of the rotational speed of the shaving cutter 118 by the processing of FIG. 3 or FIG. 4 is not particularly limited, and the resonance between the shaving cutter 118 and other elements can be avoided by increasing the frequency. However, if the frequency is increased too much, the work efficiency may be inferior. Therefore, it is desirable to perform at least when the shaving cutter 118 is replaced. By setting the rotational speed every time the shaving cutter 118 is replaced, the service life of the shaving cutter 118 can be more reliably extended without greatly deteriorating the work efficiency.

  Further, according to the processing of FIG. 3, the user can set the rotation speed so that the shaving cutter 118 does not resonate. On the other hand, according to the process of FIG. 4, since the rotation speed at which the shaving cutter does not resonate is automatically set on the control unit 200 side, the burden on the user can be reduced.

  The present invention can be applied not only to the shaving process of the above embodiment but also to a processing technique for honing the tooth surface of the gear with the processed gear.

It is a schematic explanatory drawing of the processing apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the example of the process which CPU211 performs. It is a flowchart which shows the example of the process which CPU211 performs. It is a flowchart which shows the example of the process which CPU211 performs. (A) And (b) is a figure which shows the example of the vibration analysis result by a FFT analyzer.

Explanation of symbols

111 Motor 112 Subshaft 114 Main Shaft 116, 117 Bearing 118 Shaving Cutter 119 Vibration Detection Sensor 122 Work Gear 210 Control Unit 250 FFT Analyzer

Claims (6)

In a gear machining method for rotating a work tool in mesh with a work gear, and finishing a tooth surface of the work gear,
A detection step of detecting vibration generated by meshing of the machining tool and the work gear;
An analysis step for analyzing the frequency characteristics of vibration detected in the detection step;
Based on the analysis result of the analysis step, a setting step for setting the rotational speed of the processing tool,
A gear machining method comprising the steps of:   The gear machining method according to claim 1, wherein the detection step, the analysis step, and the setting step are performed at least when the machining tool is replaced. In a gear machining apparatus that rotates a work tool in mesh with a work gear, and finishes the tooth surface of the work gear,
Drive means for rotationally driving the machining tool;
Detecting means for detecting vibration generated by meshing of the machining tool and the work gear;
Analyzing means for analyzing frequency characteristics of vibration detected by the detecting means;
Setting means for setting the rotational speed of the machining tool by the driving means;
A gear machining apparatus comprising: The drive means
A spindle connected to the machining tool;
A bearing portion that rotatably supports the main shaft,
The gear processing apparatus according to claim 3, wherein the detection unit is attached to the bearing portion. A display means for displaying the analysis result of the analysis means;
The gear processing apparatus according to claim 3 or 4, wherein the setting means includes an input means for a user to input the rotation speed. The setting means includes
Based on the analysis result of the analysis means, determination means for determining whether or not a vibration level at a frequency defined by the number of teeth of the machining tool and the rotation speed of the machining tool exceeds a specified value;
Changing means for changing the rotational speed when the determination means determines that the vibration level exceeds the specified value;
The gear machining apparatus according to claim 3 or 4, further comprising:

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