JP2013169621A - Method for machining gear and device for creating nc data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for machining a gear by which such a gear can be machined that an adjacent pitch error caused by wear of a tool is made small, without correcting a depth of cut according to wear of the tool.SOLUTION: When two adjacent desired tooth grooves of a gear W are defined as a first tooth groove 1g and a second tooth groove 2g, a tooth groove machining order 1c to 16c is allotted in such a way that: in a first rotative direction, odd machining order numbers are allotted to the tooth grooves starting from the first tooth groove 1g to the adjacent tooth grooves in an ascending order; and in a second rotative direction, even machining order numbers are allotted to the tooth grooves starting from the second tooth groove 2g to the adjacent tooth grooves in an ascending order. The tooth grooves are machined in accordance with the allotted tooth groove machining order.

Description

  The present invention relates to a gear machining method and NC data creation device for machining a gear using a machine tool.

Since the gear pitch error causes vibration, noise, and the like during the rotation of the gear, it is necessary to set the gear pitch error below a predetermined value. In particular, if the adjacent pitch error, which is the difference between adjacent single pitch dimensions, is large, the tooth meshing does not move smoothly to the adjacent tooth, which generates excessive impact and noise. is important.
As shown in FIG. 8, when the gear teeth are processed in order, one tooth groove 1c and the last 16th tooth groove 16c are adjacent to each other. Since the tool 7 is worn according to the amount of machining, the tooth gap is gradually narrowed by the amount of wear of the tool. As shown in FIG. 9, when the radial wear amount of the tool from the end of the processing of the tooth groove 1c to the end of the processing of the tooth groove 16c is u, a single space between the tooth groove 1c and the tooth groove 16c in the tooth surface a direction is shown. The single pitch Pr ₁₆ is larger than the single pitch Pr ₁ between the tooth groove 1c and the tooth groove 2c and the single pitch Pr ₁₅ between the tooth groove 15c and the tooth groove 16c, and is single in the tooth surface b direction. The pitch Pr ₁₆ ′ is reduced by u. That is, the adjacent pitch error increases. In order to reduce the adjacent pitch error due to the wear of the tool, there is a conventional technique for reducing the pitch error by changing the cutting depth of the tool according to the wear of the tool. (See Patent Document 1)

JP 2000-280119 A

In the prior art, it is necessary to predict the amount of wear of the tool in advance and to correct the amount of cutting of the tool in accordance with the increase in the amount of machining. The amount of wear of the tool varies depending on the machining conditions and the material of the workpiece, and it is necessary to perform test processing in advance in order to predict the accurate amount of wear, which requires man-hours. If the number of machining is small, the test machining is omitted and the wear amount is predicted from the standardized data, but the accuracy is deteriorated.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a machining method capable of gear processing with a small adjacent pitch error without correcting the depth of cut according to tool wear.

A feature of the invention according to claim 1 for solving the above-described problem is that in a gear machining method for machining a tooth groove of the gear to be machined one by one by moving a workpiece gear and a tool relatively,
The total number of the tooth gaps is n, and an integer number sequence that is continuous in ascending order from 1 to n is divided into desired m sections including two or more numbers, and the first number in order from the smallest number is included. Section, second section,... M section, desired adjacent tooth gaps as first tooth groove and second tooth groove, and the rotation direction from the first tooth groove to the second tooth groove is the second rotation direction. When the rotation direction from the second tooth gap to the first tooth gap is the first rotation direction,
The tooth gap processing order, which is the order in which the tooth grooves are processed,
Assign the odd number of the first section from the first tooth gap to the tooth groove in the first rotation direction in ascending order,
Allocating the even number of the first section from the second tooth gap to the tooth groove in the second rotational direction in ascending order,
Assign the odd number of the second section in ascending order from the tooth gap adjacent to the tooth groove assigned the maximum number of the number of the first section of one,
Assign the even number of the second section in ascending order from the tooth gap adjacent to the tooth groove that assigned the maximum number of the number of the first section of the other,
In the same manner, the odd and even numbers in the same section are assigned up to the m-th section in ascending order from the tooth gap adjacent to the tooth gap to which the maximum number of the previous section is assigned.
A processing order allocating step for allocating to the gear to be processed,
It is provided with the gear processing process which processes the said to-be-processed tooth space in the order allocated by the said process order allocation process.

  According to the gear machining method of this claim, since the machining order of adjacent tooth gaps is not separated by 3 or more, there is little adjacent pitch error due to tool wear associated with machining.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, only odd numbers are assigned to the tooth grooves in the first rotation direction, and only even numbers are assigned to the tooth grooves in the second rotation direction. is there.

  According to the gear machining method of the present claim, since the machining order of adjacent tooth gaps is not separated by two or more, the adjacent pitch error due to tool wear accompanying machining is small.

A feature of the invention according to claim 3 is an NC data creating apparatus for creating NC data for indexing and processing the tooth grooves of the gear to be processed one by one in the order of gear teeth.
Input means for inputting data indicating the shape of the gear to be processed and the tool, processing conditions, and the like;
The tooth gap processing order, which is the order in which the tooth grooves are processed,
The total number of the tooth gaps is n, and an integer number sequence that is continuous in ascending order from 1 to n is divided into desired m sections including two or more numbers, and the first number in order from the smallest number is included. Section, second section,... M section, desired adjacent tooth gaps as first tooth groove and second tooth groove, and the rotation direction from the first tooth groove to the second tooth groove is the second rotation direction. When the rotation direction from the second tooth gap to the first tooth gap is the first rotation direction,
Assign the odd number of the first section from the first tooth gap to the tooth groove in the first rotation direction in ascending order,
Assign the even number of the first section from the second tooth gap to the tooth groove in the second rotational direction in ascending order,
The odd number of the second section is assigned in ascending order from the tooth gap adjacent to the tooth gap assigned the maximum number of one first section,
Assign the even number of the second section in ascending order from the tooth gap adjacent to the tooth groove that assigned the maximum number of the number of the other first section,
In the same manner, the odd and even numbers in the same section are assigned up to the m-th section in ascending order from the tooth gap adjacent to the tooth gap to which the maximum number of the previous section is assigned.
A processing order calculating means determined by the above, and an angle calculating means for calculating an index angle of the gear to be processed when processing a predetermined tooth gap based on the tooth groove processing order calculated by the processing order calculating means;
Tooth gap machining NC data creation means for creating tooth gap machining NC data, which is machining NC data for machining one tooth gap, based on the shape of the gear to be machined and the tool, and the machining order calculation means The gear to be machined based on the calculated tooth gap machining order, the index angle of the gear to be machined computed by the angle computing means, and the tooth gap machining NC data created by the tooth groove machining data creating means And NC data creating means for creating NC data for processing.

  According to the first and second aspects of the present invention, since the processing order of adjacent tooth spaces is not separated by 3 or more, the difference in tool wear between adjacent tooth spaces is the difference in tool wear due to processing of two grooves. It won't get bigger. For this reason, a gear having a small adjacent pitch error due to tool wear can be machined.

  According to the third aspect of the present invention, since the processing order of adjacent tooth spaces is not separated by 3 or more, the difference in tool wear between adjacent tooth spaces is larger than the difference in tool wear due to processing of two grooves. There is no. For this reason, it is possible to provide an NC data creation device capable of creating gear machining NC data capable of machining a gear with a small adjacent pitch error caused by tool wear.

1 is an overall view showing a machine tool in an embodiment of the present invention. It is a block diagram which shows the NC data production apparatus in embodiment of this invention. It is a flowchart which shows the process of the gear processing method of this invention. It is a flowchart which shows the calculation of the processing order and index angle of a tooth gap in embodiment of this invention. It is a figure which shows the processing order of the tooth gap in embodiment of this invention. It is a flowchart which shows the calculation of the tooth groove processing order and index angle in the deformation | transformation aspect of this invention. It is a figure which shows the processing order of the tooth gap in the deformation | transformation aspect of this invention. It is a figure which shows the processing order of the conventional tooth space. It is a figure which shows the relationship between tool wear and an adjacent pitch error.

  As shown in FIG. 1, the machine tool 1 includes a bed 2, and includes a table 3 that can reciprocate in the X-axis direction on the bed 2 and a column 4 that can reciprocate in the Z-axis direction orthogonal to the X-axis. . The column 4 supports the headstock 5 so as to be able to reciprocate in the Y-axis direction, and the Y-axis is orthogonal to the X-axis and the Z-axis. The headstock 5 includes a main shaft 6 that is rotationally driven by a main shaft rotating motor (not shown), and holds a tool 7 at the tip of the main shaft 6. An indexing device 10 is provided on the table 3, and an indexing plate 11 that is rotatably supported around an axis (B axis) parallel to the Y axis is provided at the upper end of the indexing device 10. . The index plate 11 includes a grip portion (not shown) that grips the lower end of the gear W to be processed, and can be indexed to a desired rotation angle by an index motor (not shown).

  The control device 30 includes an NC data storage unit 301, an X-axis control unit 302 that controls the feed of the table 3, a Y-axis control unit 303 that controls the feed of the headstock 5, and a Z-axis control that controls the feed of the column 4. Unit 304, a B-axis control unit 305 for controlling the rotation of the indexing plate 8 of the indexing device 7, and a spindle control unit 306 for controlling the rotation of the tool. Based on the input NC data, the X-axis, Y-axis Controls the axis, Z axis, B axis, and main axis.

  As shown in FIG. 2, the NC data creation device 50 includes a data input unit 501 (input unit), a processing order calculation unit 502 (processing order calculation unit), an angle calculation unit 503 (angle calculation unit), and a tooth gap processing NC. A data creation unit 504 (tooth gap machining NC data creation means) and a gear machining NC data creation unit 505 (NC data creation means) are provided, and predetermined NC data is started by starting a predetermined program based on the input data. Create

The gear machining process of this example will be described based on the flowchart of FIG.
First, by reading the gear machining NC data created in advance by the NC data creation device 50, the tooth gap machining NC data and indexing angle data (details will be described later) are stored in the NC data storage unit of the machine control device 30. 301 is recorded (S1). The work gear W is carried in. At this time, the rotation reference position and the tool 7 are opposed to each other in the X-axis direction by gripping the gear W to be processed by the indexing plate 11 so that the desired tooth gap matches the rotation reference position of the indexing device 10. (S2). The spindle 6 is driven to rotate the tool 7 (S3). With the machine control device 30, and 1 counter values Q ₁ for counting the number of executions of working tooth (S4). The indexing device 10 is driven, indexing the work gear W to tooth grooves of the indexing angle theta _Q1 of processing in the _{first Q} (S5). In accordance with the tool path instructions of the tooth gap machining NC data, the tool 7 is moved along the tooth groove contour by moving the X, Y, and Z axes to process one tooth groove. (S6). 1 is added to the value of the counter _{Q 1} (S7). It is determined whether all the tooth gaps have been processed. Determines whether n is larger than the value of the counter Q ₁ is the total number of tooth spaces. If Q ₁ > n, the process moves to step S9. If not, the process moves to step S5, and the next tooth gap processing is repeated (S8). The X, Y, Z, and B axes are moved to return to a predetermined processing source position (S9). The rotation of the tool 7 is stopped (S10). The work gear W is unloaded (S11).

  Tooth gap machining NC data for machining one tooth groove is conventionally performed using a machining path determined from the tooth groove machining shape and tool 7 shape defined by the module and tooth width of the gear W to be machined. It is created in the tooth gap machining NC data creation unit 504 by the usual method.

  Next, a process for calculating indexing angle data for each processing order, which is performed by the NC data creation device 50, will be described as a processing order allocation process. The indexing angle data according to the processing order is data indicating the processing order of the tooth grooves of the gear W to be processed and the indexing angle at the time of processing each tooth groove. Here, an example in which an odd-numbered machining order is arranged clockwise (first rotation direction) and an even-numbered machining order is arranged counterclockwise (second rotation direction) will be described based on the flowchart of FIG.

First, the value of the number of teeth (same as the number of tooth gaps) n of the work gear W is read by the data input unit 501 (S21). Calculate the index angle Θ _kg for each tooth number kg. Here, the tooth gap number is a number assigned from 1 g shown in FIG. 5 to 16 g counterclockwise with a subscript g. The index angle of the tooth gap 1g is set to 0, and the angle is increased counterclockwise. Since the increment angle for each tooth gap is 360 / n degrees where n is the number of tooth grooves, the index angle Θ _kg of the tooth gap kg can be calculated by Θ _kg = (kg−1) · 360 / n. . (S22). Assign an odd number of tooth gap machining order to each tooth groove. The number c of the processing order is attached with a subscript c, and as shown in FIG. 5, the odd-numbered order is changed from the 1 g tooth groove (first tooth groove) to the tooth groove adjacent in the clockwise direction (first rotation direction). Assign in ascending order. (S23). The even order is assigned in ascending order from the 2g tooth space (second tooth space) to the tooth space adjacent in the counterclockwise direction (second rotation direction) (S24). The tooth gap number and the index angle are associated with the processing order of the tooth gap. By integrating the indexing angle for the tooth gap number calculated in step S22 and the processing order for the tooth groove number assigned in step S23 and step S24, the corresponding tooth gap number for a predetermined processing order, By assigning an index angle, index angle data for each processing order is created (S31).

  As described above, when the processing order is assigned to the gear having n of 16 teeth, the odd processing order 1c to 15c is changed from the tooth groove 1g to the tooth groove 10g in the ascending order as shown in FIG. 2c to 16c, which are even machining orders, are assigned from the tooth gap 2g to the tooth gap 9g in ascending order counterclockwise. In this case, the difference in the processing order of adjacent tooth gaps is within 2.

When the influence of the indexing accuracy of the gear W is removed, if the tooth gaps are machined in the above order, the difference in the single pitch of all adjacent tooth gaps is less than the radial wear amount of the tool due to the machining of the two tooth grooves. It becomes.
That is, according to the present invention, it is possible to realize a gear machining method in which the adjacent pitch error is equal to or less than the radial wear amount of the tool due to machining of two tooth spaces.

<Deformation of this embodiment>
In the above groove processing order, all odd-numbered processing orders are adjacent to each other in ascending order, and all even-numbered processing orders are adjacent to each other in ascending order. However, odd-numbered numbers and even-numbered numbers may be alternately adjacent to each other. The calculation process for determining the processing order will be described with reference to the flowchart of FIG.

First, the value of the number of teeth n and the value of the number of divisions m of the gear W to be processed are read by the data input unit 501 (S51). Calculate the index angle Θ _kg for each tooth number kg. Here, the tooth gap number is a number assigned from 1 g shown in FIG. 7 to 16 g counterclockwise. The index angle of the tooth groove 1 g is set to 0, and the angle is increased counterclockwise. Since the increment angle for each tooth gap is 360 / n degrees where n is the number of teeth, the index angle Θ _kg of the tooth gap kg can be calculated as Θ _kg = (kg−1) · 360 / n. (S52). The integer sequence from 1 to n is divided into m. The number included in one of the 1 to m-1 sections is S, which is an integer part of n / m, and the number of the mth section is nS · m (S53).

Assign an odd number of tooth gap processing order to the tooth gap. The odd number of the first section is assigned in ascending order to the tooth gap adjacent in the clockwise direction from the tooth gap 1g (S54). The even number of the first section is assigned in ascending order from the tooth gap 2g to the tooth gap adjacent in the counterclockwise direction (S55). The value of counter _{Q 2} to which indicate the segment number and 2 (S56). Determine whether the assignment is complete. If Q ₂ > m, the process moves to step S60, and if not, the process moves to step S58 (S57). Odd first Q ₂ segment, the (Q 2 _-1) allocated from the tooth groove in ascending order the maximum number of even segment is adjacent to the tooth that is allocated, an even number of first Q ₂ segment, the (Q ₂ - 1) Allocating in ascending order from the tooth gap adjacent to the tooth gap to which the odd maximum number of sections is assigned (S58). It adds 1 to the value of the counter _{Q 2.} Q ₂ = Q ₂ +1 is executed (S59). The tooth gap number and the index angle are associated with the processing order of the tooth gap. By integrating the indexing angle for the tooth number calculated in step S52 and the processing order for the tooth number assigned in steps S53 to S59, the tooth number and indexing angle corresponding to the predetermined processing order are obtained. Assign (S60).

  Here, FIG. 7 shows an example of assignment of the division of the sequence and the processing order when the number of teeth n = 16 and the number of divisions m = 3. As shown in the lower part of FIG. 7, the numerical sequence is divided into three sections, and the difference in the processing order of adjacent tooth spaces is within three. In this case, the difference in the processing order of the adjacent tooth gaps is larger than when all odd processing orders are adjacent in ascending order and all even processing orders are adjacent in ascending order, but the difference between each tooth gap is The total required rotation angle of the indexing device 10 is reduced, and the time required for processing can be shortened.

In the above embodiment, the odd-numbered order is arranged in ascending order clockwise, but may be in ascending order counterclockwise.
Moreover, as a processing method, it can apply to all the processing methods in which wear of a tool generate | occur | produces by processing of a tooth gap, such as the grinding process which uses a grindstone as a tool.

1: Machine tool 2: Bed 3: Table 4: Column 5: Spindle 6: Spindle 7: Tool 10: Indexing device 11: Indexing plate W: Gear to be processed 30: Machine control device 50: NC data creation device 501 : Data input unit 502: Machining order calculation unit 503: Angle calculation unit 504: Tooth gap machining NC data creation unit 505: Gear machining NC data creation unit

Claims (3)

In the gear processing method of moving the gear to be processed and the tool relatively, and processing the tooth groove of the gear to be processed one tooth groove at a time,
The total number of the tooth gaps is n, and an integer number sequence that is continuous in ascending order from 1 to n is divided into desired m sections including two or more numbers, and the first number in order from the smallest number is included. Section, second section,... M section, desired adjacent tooth gaps as first tooth groove and second tooth groove, and the rotation direction from the first tooth groove to the second tooth groove is the second rotation direction. When the rotation direction from the second tooth gap to the first tooth gap is the first rotation direction,
The tooth gap processing order, which is the order in which the tooth grooves are processed,
Assign the odd number of the first section from the first tooth gap to the tooth groove in the first rotation direction in ascending order,
Allocating the even number of the first section from the second tooth gap to the tooth groove in the second rotational direction in ascending order,
The odd number of the second section is assigned in ascending order from the tooth gap adjacent to the tooth gap assigned the maximum number of one first section,
Assign the even number of the second section in ascending order from the tooth gap adjacent to the tooth groove that assigned the maximum number of the number of the other first section,
In the same manner, the odd and even numbers in the same section are assigned up to the m-th section in ascending order from the tooth gap adjacent to the tooth gap to which the maximum number of the previous section is assigned.
A processing order allocating step for allocating to the gear to be processed,
A gear machining method comprising a gear machining process for machining the tooth grooves to be machined in the order assigned in the machining order assignment process.   The gear machining method according to claim 1, wherein only odd numbers are assigned to the tooth grooves in the first rotation direction, and only even numbers are assigned to the tooth grooves in the second rotation direction. In the NC data creation device that creates NC data for indexing and processing the tooth grooves of the gear to be processed one by one,
Input means for inputting data indicating the shape of the gear to be processed and the tool, processing conditions, and the like;
The tooth gap processing order, which is the order in which the tooth grooves are processed,
The total number of the tooth gaps is n, and an integer number sequence that is continuous in ascending order from 1 to n is divided into desired m sections including two or more numbers, and the first number in order from the smallest number is included. Section, second section,... M section, desired adjacent tooth gaps as first tooth groove and second tooth groove, and the rotation direction from the first tooth groove to the second tooth groove is the second rotation direction. When the rotation direction from the second tooth gap to the first tooth gap is the first rotation direction,
Assign the odd number of the first section from the first tooth gap to the tooth groove in the first rotation direction in ascending order,
Assign the even number of the first section from the second tooth gap to the tooth groove in the second rotational direction in ascending order,
The odd number of the second section is assigned in ascending order from the tooth gap adjacent to the tooth gap assigned the maximum number of one first section,
Assign the even number of the second section in ascending order from the tooth gap adjacent to the tooth groove that assigned the maximum number of the number of the other first section,
In the same manner, the odd and even numbers in the same section are assigned up to the m-th section in ascending order from the tooth gap adjacent to the tooth gap to which the maximum number of the previous section is assigned.
A processing order calculating means determined by the above, and an angle calculating means for calculating an index angle of the gear to be processed when processing a predetermined tooth gap based on the tooth groove processing order calculated by the processing order calculating means;
Tooth gap machining NC data creation means for creating tooth gap machining NC data, which is machining NC data for machining one tooth gap, based on data indicating the shape of the gear to be machined and the tool, and the machining order Based on the tooth gap machining order computed by the computing means, the index angle of the gear to be machined computed by the angle computing means, and the tooth gap machining NC data created by the tooth gap machining data creating means An NC data creation device comprising: NC data creation means for creating NC data for machining a workpiece gear.

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