JP7456219B2 - Gear processing equipment and gear processing method - Google Patents

Description

The present invention relates to a gear processing device and a gear processing method.

Generally, when continuously machining a workpiece, machining resistance increases due to tool wear that occurs in gear cutting tools, etc., so chatter vibration (or machining vibration) may occur. In order to suppress such chatter vibrations, techniques disclosed in Patent Document 1 and Patent Document 2 have been known.

Patent Document 1 discloses a technology for a gear cutting device that varies the rotation speed of either the workpiece or the gear cutting tool, and synchronizes the rotation speed of the other of the workpiece and the gear cutting tool. Patent Document 2 discloses a technology for a machine tool that changes the rotation speed of the spindle to an optimal value in response to chatter vibration.

JP 2018-62056 A JP2014-61568A

By the way, when gear machining is performed on a workpiece using a gear machining device, usually one of the variation width and variation frequency when varying the rotational speed is adjusted in anticipation of chatter vibration occurring during continuous machining. is set large so as to provide some margin from the start of machining. As a result, workpieces produced in lots are produced as good products in which deterioration of surface quality due to chatter vibration is effectively suppressed.

However, electric power is required to vary the rotational speed of either the workpiece or the gear cutting tool and to synchronize the rotational speed of the other of the workpiece or the gear cutting tool. In this case, if the variation width and variation frequency for varying the rotational speed are set too large, this will result in wasted power consumption, especially in a situation where the gear cutting tool has little wear.

An object of the present invention is to provide a gear machining device and a gear machining method that can reduce wasteful power consumption when machining gears by varying and synchronizing the rotational speeds of a workpiece and a gear cutting tool.

(gear processing equipment)
A first aspect of the gear processing device of the present invention controls the synchronous rotation of a gear cutting tool and a workpiece, and also controls the relative movement of the gear cutting tool and the workpiece along the rotational axis direction of the workpiece . A gear processing device for processing gears on the workpiece, comprising a control device for controlling the
The control device includes :
A rotational speed fluctuation range representing a fluctuation range when varying the rotational speed of the synchronous rotation according to a state value representing a processing state of the workpiece by the gear cutting tool regarding machining of the workpiece, and the rotational speed a fluctuation condition changing unit that changes at least one of the rotational speed fluctuation frequencies representing the frequency at which the rotational speed is varied ;
The rotational speed of the synchronous rotation of the gear cutting tool and the workpiece is controlled to vary based on at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency changed by the fluctuation condition changing unit, and the rotational speed of the synchronous rotation of the gear cutting tool and the workpiece is controlled A gear processing apparatus includes a control section that fluctuates and controls a feed rate of relative movement between the gear cutting tool and the workpiece so as to be synchronized with a rotational speed of rotation .
A second aspect of the gear processing device of the present invention is to control the synchronous rotation of a gear cutting tool and a workpiece, and to move the gear cutting tool and the workpiece relative to each other along the rotational axis direction of the workpiece. A gear processing device for processing gears on the workpiece, comprising a control device for controlling the
The control device includes:
A rotational speed fluctuation range representing a fluctuation range when varying the rotational speed of the synchronous rotation according to a state value representing a processing state of the workpiece by the gear cutting tool regarding machining of the workpiece, and the rotational speed comprising a fluctuation condition changing unit that changes at least one of the rotational speed fluctuation frequencies representing the frequency at which the rotational speed fluctuation frequency is varied;
The variation condition changing unit is included in the gear processing device and determines whether to change or maintain at least one of the rotational speed variation width and the rotational speed variation frequency based on the balance between machining efficiency and energy saving.

(Gear processing method)
In a first aspect of the gear machining method of the present invention, the gear cutting tool and the workpiece are rotated synchronously, and the gear cutting tool is moved relative to the workpiece along the rotational axis direction of the workpiece . A gear machining method for machining a gear on the workpiece , comprising:
acquiring a state value representing a machining state of the workpiece by the gear cutting tool regarding machining of the workpiece , and determining whether or not the state value is larger than a preset reference value;
A rotational speed fluctuation range representing a fluctuation range when the rotational speed of the synchronous rotation is varied, and a frequency when the rotational speed is varied in accordance with a determination result that the state value is larger than a preset reference value. change at least one of the rotational speed fluctuation frequencies representing
Variably controlling the rotational speed of the synchronous rotation in the gear cutting tool and the workpiece based on at least one of the changed rotational speed fluctuation width and the rotational speed fluctuation frequency, and synchronizing with the rotational speed of the synchronous rotation. The present invention provides a gear machining method that variably controls the feed rate of relative movement between the gear cutting tool and the workpiece.
A second aspect of the gear machining method of the present invention is to move the gear cutting tool relative to the workpiece along the rotation axis direction of the workpiece while rotating the gear cutting tool and the workpiece synchronously. A gear machining method for machining a gear on the workpiece, comprising:
Obtaining a state value representing a machining state of the workpiece by the gear cutting tool regarding machining of the workpiece, and determining whether the state value is larger than a preset reference value;
A rotational speed fluctuation range representing a fluctuation range when the rotational speed of the synchronous rotation is varied, and a frequency when the rotational speed is varied, in accordance with a determination result that the state value is larger than a preset reference value. change at least one of the rotational speed fluctuation frequencies representing
The gear machining method includes determining whether to change or maintain at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency based on the balance between machining efficiency and energy saving.

According to these, at least one of the rotational speed fluctuation range and the rotational speed fluctuation frequency can be changed according to the state value. As a result, the power consumption of a gear machining device that can change at least one of the rotational speed fluctuation range and the rotational speed fluctuation frequency according to the state value can be reduced compared to the power consumption when excessive rotational speed fluctuation range and rotational speed fluctuation frequency are uniformly applied in lot production. Therefore, the amount of unnecessary power consumption can be significantly reduced.

It is a perspective view of a gear processing device. FIG. 2 is an enlarged view of a gear cutting tool fixed to a rotating main shaft. It is a figure which shows the operation|movement of a gear cutting tool and a workpiece when performing skiving processing. FIG. 2 is a block diagram showing the configuration of a control device. It is a graph showing fluctuations in the rotational speed of a gear cutting tool and a workpiece. It is a flowchart of a gear machining processing program executed by a control device. FIG. 3 is a diagram showing a change in stability limit (depth of cut) when the rotational speed fluctuation range is changed to a large value. FIG. 7 is a diagram showing a change in power consumption when the rotational speed fluctuation width is changed to a large value. FIG. 7 is a diagram showing a change in the magnitude of machining vibration when the fluctuation conditions are changed according to the production quantity, which is a state value. It is a figure which shows the change of the amount of power consumption when a fluctuation condition is changed according to the production number which is a state value. FIG. 7 is a diagram showing a simulation result of a change in stability limit (depth of cut) when the rotational speed fluctuation frequency is changed to a large value according to the first other example. 13 is a flowchart of a gear machining processing program executed by the control device according to a third modified example. FIG. 10 is a diagram showing a change in the magnitude of machining vibration with respect to a determination value in a case where the fluctuation conditions are changed according to the production quantity, which is a state value, according to a fourth alternative example. It is a flowchart of the gear machining processing program executed by the control device according to a fourth alternative example. 4 shows the movement of a gear cutting tool and a workpiece during hobbing in another example of a gear cutting machine.

(1. Applicable gear processing equipment)
A gear processing device moves the gear cutting tool relative to the workpiece along the rotational axis direction of the workpiece while varying the rotational speed of the gear cutting tool and the workpiece and rotating the gear cutting tool and the workpiece synchronously. Machining gears on a workpiece by moving the gears relative to each other. In this example, a gear processing device is equipped with a skiving cutter as a gear cutting tool, and a case is illustrated in which a gear is processed into a workpiece by skiving processing. In this case, the gear processing device uses three linear axes (X-axis, Y-axis, and Z-axis) and two rotary axes (A-axis (swivel table axis) and C-axis (workpiece axis)) that are orthogonal to each other as drive axes. An example of this is a vertical or horizontal machining center having the following.

(1-1. Configuration of gear processing device 1)
As shown in FIG. 1 (see also the block diagram in FIG. 4), the gear processing apparatus 1 of this example includes a bed 10, a column 20, a saddle 30, a rotating main shaft 40, a table 50, and a tilt table 60. , a turntable 70, a holder 80, and a control device 100.

Bed 10 is placed on the floor. A column 20 and an X-axis motor are provided on the upper surface of the bed 10, and the column 20 is provided so as to be movable in the X-axis direction (horizontal direction) by being driven by the X-axis motor. Further, a saddle 30 and a Y-axis motor 11 are provided on the side surface of the column 20, and the saddle 30 is provided movably in the Y-axis direction (vertical direction) by the Y-axis motor 11. The rotating main shaft 40 is rotatably provided by a main shaft motor 41 housed within the saddle 30 . A gear cutting tool 42 is fixed to the tip of the rotating main shaft 40, and the gear cutting tool 42 rotates as the rotating main shaft 40 rotates.

Here, the gear cutting tool 42 will be explained with reference to FIG. The gear cutting tool 42 is a skiving cutter having a plurality of blades 42a on its outer peripheral surface, and the end face of each blade 42a constitutes a rake face having a rake angle γ. The rake surface of each blade 42a may be tapered (inward) about the central axis of the gear cutting tool 42, or may be formed into a surface facing in a different direction for each blade 42a.

A table 50 and a Z-axis motor 12 are provided on the top surface of the bed 10. The table 50 is provided movably in the Z-axis direction (horizontal direction) by the Z-axis motor 12. A pair of tilt table support parts 61 that support the tilt table 60 are provided on the upper surface of the table 50.

A tilt table 60 is provided in the tilt table support section 61 so as to be swingable around the A axis (horizontal direction). A table motor 62 is provided on the bottom surface of the tilt table 60, and the turntable 70 is provided to be rotatable around a C axis perpendicular to the A axis by the table motor 62. A holder 80 that holds the workpiece W is attached to the turntable 70.

The control device 100 controls the rotation speed V1 of the workpiece W, the rotation speed V2 of the gear cutting tool 42, and the feed speed V4 at which the gear cutting tool 42 moves relative to the workpiece W along the rotation axis direction (C-axis direction) of the workpiece W. Note that, in this example, the table 50 is configured to be movable in the Z-axis direction, but the column 20 may be configured to be movable in the Z-axis direction instead of the table 50.

Here, in this example, as shown in FIG. 3, the gear processing device 1 processes a gear on the workpiece W by skiving processing. Specifically, the gear processing device 1 tilts the C-axis, which is the rotation axis of the workpiece W, with respect to the rotation axis O of the gear cutting tool 42 by swinging the tilt table 60 around the A-axis. Incidentally, the inclination angle of the rotational axis O of the gear cutting tool 42 with respect to the C-axis of the workpiece W is referred to as the intersection angle δ. Then, the gear processing device 1 rotates the workpiece W and the gear cutting tool 42 synchronously and sends the gear cutting tool 42 in the direction of the center axis of the workpiece W (relatively moving it), thereby attaching the gear to the workpiece W. Process.

Further, in the skiving process, the rotational speed V2 of the gear cutting tool 42 and the rotational speed V1 of the workpiece W are determined based on the intersection angle δ and the cutting speed V3. The cutting speed V3 and the feed rate V4 depend on the machining time (cycle time) required for gear machining, the specifications of the gear cutting tool 42, the material of the workpiece W, the helix angle of the gear formed on the workpiece W, etc. Set based on That is, the cutting speed V3 and the feed speed V4 are set to optimal speeds in consideration of the machining efficiency during gear machining, the tool life (wear) of the gear cutting tool 42, etc. Further, in skiving processing, as the cutting speed V3 and feed speed V4 are increased, processing efficiency improves, but quality such as surface texture (tooth trace error) tends to deteriorate.

In this regard, the gear processing device 1 sets the rotational speed V1 of the workpiece W, which is determined based on the optimum cutting speed V3 and the intersection angle δ, as the reference rotational speed Nw. Then, the gear processing device 1 performs gear processing while varying the rotational speed V1 of the workpiece W based on the reference rotational speed Nw. Accordingly, the gear processing device 1 changes the rotation speed V2 of the gear cutting tool 42 and synchronizes it with the rotation speed V1 of the workpiece W during gear processing.

Furthermore, the gear processing device 1 sets the feed rate V4 of the workpiece W, which is determined based on the optimum cutting speed V3 and the intersection angle δ, as the reference feed rate Fw. Then, the gear processing device 1 varies the feed rate V4 so as to be synchronized with the rotational speed V1 of the workpiece W, using the reference feed rate Fw as a reference.

(1-2. Regarding the control device 100)
The control device 100 includes a reference rotation speed setting section 110, a variation condition setting section 120, a workpiece rotation speed control section 130, a tool rotation speed control section 140, a reference feed speed setting section 150, and a feed speed control section 160. Mainly equipped with.

The reference rotation speed setting unit 110 sets a reference rotation speed Nw determined based on the cutting speed V3 and the intersection angle δ. The fluctuation condition setting unit 120 sets a fluctuation condition Nwj including a rotation speed fluctuation width and a rotation speed fluctuation frequency of the rotation speed V1 of the workpiece W, according to a state value representing the machining state of the workpiece W. In this example, the variation condition setting unit 120 sets the variation condition Nwj by changing it according to the production number Np of the workpiece W, which is a state value.

Here, the rotation speed fluctuation range of the rotation speed V1 of the workpiece W, as shown in FIG. is set to suppress the occurrence of Further, the rotational speed fluctuation frequency of the rotational speed V1 of the workpiece W represents the frequency at which the rotational speed is varied, and the rotational speed V2 of the gear cutting tool 42, the rotational speed V1 of the workpiece W, the cutting force of the workpiece W, etc. It is set based on the natural frequency, which is the vibration characteristic of the workpiece W, which is determined by simulation based on , measurement by hammering, etc. Note that the rotational speed fluctuation frequency of the rotational speed V1 of the workpiece W is set based on the natural frequency, which is the vibration characteristic of the gear cutting tool 42, the rotating main shaft 40, and the machine body of the gear processing device 1, which are similarly measured and determined. It's okay to be.

That is, the rotational speed fluctuation range and the rotational speed fluctuation frequency can be set based on the stability limit increase rate (stable limit equivalent to the cutting depth) which represents the relationship between the fluctuation of the rotational speed V1 of the workpiece W and the chatter vibration (regenerative chatter vibration, etc.) that occurs in the workpiece W during gear machining. Here, the higher the stability limit (stable limit increase rate), the more stable gear machining can be performed without generating chatter vibration in the workpiece W, and as a result, the cutting depth can be increased to improve machining efficiency. For details on the stability limit increase rate and the stability limit, see, for example, JP 2018-62056 A.

Note that since the rotation speed fluctuation period can be expressed as the reciprocal of the rotation speed fluctuation frequency (1/rotation speed fluctuation frequency), the fluctuation condition setting unit 120 sets the fluctuation condition Nwj including the rotation speed fluctuation width and the rotation speed fluctuation period. Can be set. Further, the fluctuation condition setting unit 120 can also set the rotation speed fluctuation width and rotation speed fluctuation frequency (rotation speed fluctuation period) of the rotation speed V2 of the gear cutting tool 42.

The variable condition setting unit 120 includes a simulation calculation unit 121, a state value determination unit 122, and a variable condition change unit 123. The simulation calculation unit 121 simulates the stability limit, specifically, the stability limit increase rate, by calculation.

The state value determining unit 122 acquires the number Np of produced workpieces W, which is a state value, from a counter (not shown) that is provided in the gear processing apparatus 1 and counts the number of produced workpieces W. Then, the state value determination unit 122 compares the obtained production number Np with a plurality of reference values Sn1, Sn2, and Sn3 set in advance regarding the production number. Note that the reference value Sn1, the reference value Sn2, and the reference value Sn3 are set so that the reference value Sn1 is the smallest, the reference value Sn2 is larger than the reference value Sn2, and the reference value Sn3 is larger than the reference value Sn2. The state value determining unit 122 then compares the production number Np with each of the reference values Sn1, Sn2, and Sn3, and determines whether the production number Np is larger than each of the reference values Sn1, Sn2, and Sn3.

The variation condition change unit 123 changes the variation condition Nwj in stages according to the production number Np determined by the state value determination unit 122. That is, according to the determination by the status value determining unit 122, the variation condition changing unit 123 of this example changes the first variation condition shown in Table 1 below as the variation condition Nwj when the production number Np, which is the status value, is less than or equal to the reference value Sn1. Maintain Nwj1.

The variable condition change unit 123 also changes the variable condition Nwj1 from the first variable condition Nwj1 to the second variable condition Nwj2 shown in Table 1 below when the production number Np is greater than the reference value Sn1 and is equal to or less than the reference value Sn2, according to the determination result by the state value determination unit 122. Furthermore, the variable condition change unit 123 changes the variable condition Nwj from the second variable condition Nwj2 to the third variable condition Nwj3 shown in Table 1 below when the production number Np is greater than the reference value Sn2 and is equal to or less than the reference value Sn3, according to the determination result by the state value determination unit 122.

The first fluctuation condition Nwj1 of this example is a fluctuation condition Nwj in which the rotation speed fluctuation width is set to 5% and the rotation speed fluctuation frequency is set to 1 Hz. Further, the second fluctuation condition Nwj2 of this example is a fluctuation condition Nwj in which the rotation speed fluctuation width is set to 10% and the rotation speed fluctuation frequency is set to 1 Hz. Furthermore, the third variation condition Nwj3 of this example is a variation condition Nwj in which the rotation speed variation width is set to 15% and the rotation speed variation frequency is set to 1 Hz. That is, in the first variation condition Nwj1 to the third variation condition Nwj3 of this example, the rotation speed variation frequency is kept constant at 1 Hz, and only the rotation speed variation width is changed.

The workpiece rotation speed control unit 130 drives and controls the table motor 62 to vary the rotation speed V1 of the workpiece W. The tool rotation speed control unit 140 drives and controls the spindle motor 41 to vary the rotation speed V2 of the gear cutting tool 42 and synchronize the rotation speed V2 of the gear cutting tool 42 with the rotation speed V1 of the workpiece W.

The reference feed rate setting unit 150 sets a reference feed rate Fw determined based on the cutting speed V3 and the intersection angle δ. The feed rate control unit 160 drives and controls the Y-axis motor 11 and the Z-axis motor 12, and varies the feed rate V4 so that the feed rate V4 and the rotational speed V1 of the workpiece W are synchronized, and the gear cutting tool 42. The relative distance between and the workpiece W is adjusted.

(2. Gear processing (gear processing method))
Next, a gear machining program executed by the control device 100 will be described using the flowchart shown in FIG. Note that when executing the gear machining processing program, a reference rotational speed Nw is set in the reference rotational speed setting section 110, and a reference feedrate Fw is set in the reference feedrate setting section 150, respectively.

As shown in FIG. 6, execution of the gear machining processing program is started in step S10. Then, in the subsequent step S11, the simulation calculation unit 121 of the variation condition setting unit 120 executes a simulation and calculates a stability limit in order to set the variation condition Nwj for varying the rotational speed V1 of the workpiece W.

That is, the simulation calculation unit 121 obtains the reference rotation speed Nw from the reference rotation speed setting unit 110. Then, the simulation calculation unit 121 calculates the natural frequency of the workpiece W by executing a well-known simulation program stored in advance, and when changing the rotational speed fluctuation range and the rotational speed fluctuation frequency respectively. The stability limit increase rate (that is, stability limit) is calculated. After the simulation calculation unit 121 calculates the stability limit, the process proceeds to step S12.

Here, the variation condition setting unit 120 determines first variation conditions Nwj1 to third variation conditions Nwj3 when machining a gear on the workpiece W, based on the calculated stability limit. In this case, when determining the fluctuation condition Nwj, the fluctuation condition setting unit 120 changes it so that the current limit value is satisfied. Here, the current limit value is the sum of the current required to realize rotational speed fluctuation and the current required during machining, and is determined depending on the rotational speed fluctuation width and rotational speed fluctuation frequency. It is.

In step S12, the variation condition changing unit 123 sets the first variation condition Nwj1 as the variation condition Nwj when the production number Np of the workpiece W is equal to or less than the reference value Sn1. That is, in this example, the variation condition changing unit 123 sets the variation condition Nwj to the first variation condition Nwj1 in which the rotation speed variation width is 5% and the rotation speed variation frequency is 1 Hz, as shown in Table 1. Set. After the variation condition setting unit 120 (variation condition changing unit 123) sets the variation condition Nwj to the first variation condition Nwj1, the process proceeds to step S13.

In step S13, the state value determination unit 122 adds "1" to the production number Np, which is the state value of the workpiece W by the gear processing apparatus 1, by "1" each time the workpiece W is replaced. Here, the initial value of the production number Np is set to "0" by a reset process at the start of execution of the gear processing program. Note that the production number Np can also be obtained from a counter, which is not shown.

In step S14, the state value determining unit 122 determines whether the production number Np added by "1" in step S13 is less than or equal to the reference value Sn1. That is, if the production number Np is less than or equal to the reference value Sn1, the state value determination unit 122 determines "Yes" and proceeds to step S18. In this case, the gear processing device 1 performs gear processing on the workpiece W by varying the rotational speed V1 of the workpiece W according to the first variation condition Nwj1. On the other hand, if the production number Np is larger than the reference value Sn1, the state value determination unit 122 determines "No" and proceeds to step S15.

In step S15, the state value determining unit 122 determines whether the production number Np is greater than the reference value Sn1 and is less than or equal to the reference value Sn2. That is, if the production number Np is greater than the reference value Sn1 and less than the reference value Sn2, the state value determination unit 122 determines "Yes" and proceeds to step S16. On the other hand, if the production number Np is larger than the reference value Sn2, the state value determination unit 122 determines "No" and proceeds to step S17.

In step S16 of this example, when the production quantity Np is larger than the reference value Sn1 and less than or equal to the reference value Sn2, the variation condition changing unit 123 changes the variation condition Nwj from the first variation condition Nwj1 to the second variation condition Nwj2. do. That is, in this example, the variation condition changing unit 123 sets the variation condition Nwj to a second variation condition Nwj2 in which the rotation speed variation width is 10% and the rotation speed variation frequency is 1 Hz, as shown in Table 1. change. When the variation condition setting unit 120 (variation condition changing unit 123) changes the variation condition Nwj to the second variation condition Nwj2, the process proceeds to step S18.

In step S17 of this example, the variable condition changing unit 123 executes when the production quantity Np is greater than the reference value Sn2 and less than or equal to the reference value Sn3. Specifically, in step S17, the variation condition changing unit 123 changes the variation condition Nwj from the second variation condition Nwj2 to the third variation condition Nwj3. That is, in this example, the variation condition changing unit 123 sets the variation condition Nwj to a third variation condition Nwj3 in which the rotational speed variation width is 15% and the rotational speed variation frequency is 1Hz, as shown in Table 1. change. When the variation condition setting unit 120 (variation condition changing unit 123) changes the variation condition Nwj to the third variation condition Nwj3, the process proceeds to step S18.

By the way, as shown in Fig. 7, the stability limit (depth of cut) becomes larger when there is a fluctuation in the rotational speed than when there is no fluctuation in the rotational speed, and furthermore, as the width of the rotational speed fluctuation becomes larger. have a growing relationship. Therefore, from the viewpoint of machining efficiency, it is better to vary the rotational speed, and furthermore, it is better to have a larger rotational speed fluctuation range.

On the other hand, when the rotational speed of the rotating gear cutting tool 42 is varied, in addition to the power required to rotate the gear cutting tool 42 without variation, extra power is consumed to cause the variation. Therefore, as shown in FIG. 8, the amount of power consumed when the gear cutting tool 42 processes the workpiece W is lower when there is a fluctuation in the rotational speed than when there is no fluctuation in the rotational speed. The amount of power consumed increases as the rotational speed fluctuation range increases. Therefore, from the viewpoint of energy saving, it is better not to vary the rotational speed, and when it is varied, it is better to have a small rotational speed fluctuation range.

The variable condition change unit 123 therefore maintains or changes the variable condition Nwj based on the balance between processing efficiency and energy saving. That is, when the production number Np is equal to or less than the reference value Sn1, the gear cutting tool 42 has not yet worn out, and as a result, the cutting depth can be increased. Therefore, when the production number Np is equal to or less than the reference value Sn1, the processing efficiency is sufficiently ensured, so the variable condition change unit 123 maintains the first variable condition Nwj1, which has a small rotational speed fluctuation range and is effective in achieving energy saving.

Further, when it is larger than the reference value Sn1 and less than the reference value Sn2, the gear cutting tool 42 has not yet experienced significant wear and the like, and the depth of cut can be made relatively large. Therefore, when the production quantity Np is larger than the reference value Sn1 and less than the reference value Sn2, the variation condition changing unit 123 changes it to the second variation condition Nwj2, which is effective for ensuring machining efficiency and achieving energy saving. .

Furthermore, if the value is greater than the reference value Sn2 and less than the reference value Sn3, wear or the like occurs in the gear cutting tool 42, making it difficult to maintain a large depth of cut. Therefore, when the production quantity Np is larger than the standard value Sn2 and less than the standard value Sn3, the variable condition changing unit 123 changes the variable condition to the third variable condition Nwj3, which reduces the energy saving effect but can ensure machining efficiency. do.

In step S18, the control device 100 cuts the workpiece W. Specifically, the workpiece rotational speed control unit 130 controls and varies the rotational speed V1 of the workpiece W in accordance with the fluctuation conditions Nwj (optimal machining conditions) determined in step S12, S16, or S17. Thereby, the workpiece rotational speed control unit 130 controls the rotational speed V1 of the workpiece W by the rotational speed fluctuation range (speed upper limit value and speed lower limit value) and the rotational speed fluctuation frequency, as shown by the thick line in FIG. Increase or decrease iteratively.

The tool rotation speed control section 140 also controls the ratio of the number of teeth between the gear formed on the workpiece W and the gear cutting tool 42, the rotation speed V1 of the workpiece W set by the workpiece rotation speed control section 130, etc. Based on this, the rotational speed V2 of the gear cutting tool 42 is set so that the rotational speed V2 of the gear cutting tool 42 and the rotational speed V1 of the workpiece W are synchronized.

For example, it is assumed that the reference rotation speed Nw is 1000 min ⁻¹ , the rotation speed variation range is ±15%, and the ratio of the number of teeth between the gear formed on the workpiece W and the gear cutting tool 42 is 3:1. In this case, the tool rotational speed control section 140 periodically varies the rotational speed V2 of the gear cutting tool 42 in the range of 2550 min ^-1 to 3450 min ^-1 . In addition, the tool rotational speed control unit 140 controls the rotation of the gear cutting tool 42 so that the rotational speed variation frequency of the rotational speed V2 of the gear cutting tool 42 is the same as the rotational speed variation frequency of the rotational speed V1 of the workpiece W. Increase and decrease speed V2 iteratively.

Thereby, the rotational speed V2 of the gear cutting tool 42 increases and decreases periodically in synchronization with the rotational speed V1 of the workpiece W. Then, the gear cutting tool 42 performs continuous gear machining on the workpiece W while meshing with the workpiece W, and cuts the tooth surface shape on the workpiece W.

Further, the feed rate control unit 160 controls the feed rate V4 to be the rotation speed of the workpiece W based on the reference feed rate Fw set in the reference feed rate setting unit 150 and the rotation speed fluctuation frequency of the rotation speed V1 of the workpiece W. The feed rate V4 is varied so as to be synchronized with the rotational speed variation frequency of V1. As a result, the feed speed V4 increases and decreases repeatedly at a constant cycle.

In this way, the workpiece rotational speed control unit 130 repeatedly increases and decreases the rotational speed V1 of the workpiece W at high speed, and the tool rotational speed control unit 140 synchronizes the rotational speed V2 of the gear cutting tool 42 with the rotational speed V1 of the workpiece W. Furthermore, the feed speed control unit 160 varies the feed speed V4 so as to synchronize with the rotational speed fluctuation frequency of the rotational speed V1 of the workpiece W. Then, the gear machining device 1 machines a gear on the workpiece W.

Thereby, the gear processing device 1 can control the stability limit of the gear cutting tool 42 with respect to the workpiece W while suppressing chatter vibration occurring in the workpiece W in accordance with the production number Np in gear processing on the workpiece W. This allows the depth of cut to be set larger. Therefore, the gear machining device 1 can improve both the surface quality of the machined surface formed on the workpiece W and the machining efficiency, and furthermore, can save energy.

Here, the mass of the first rotating body including the workpiece W (the rotating parts of the workpiece W, the retainer 80 and the turntable 70) and the second rotating body including the gear cutting tool 42 (the gear cutting tool 42 and the rotating main shaft 40 rotating parts) are not the same. Therefore, when the rotational speed V1 of the first rotating body and the rotational speed V1 of the second rotating body fluctuate synchronously, the first moment of inertia of the first rotating body and the second moment of inertia of the second rotating body are different. Then, due to the difference between the first moment of inertia of the first rotating body and the second moment of inertia of the second rotating body, a synchronization error in the rotational phases of the workpiece W and the gear cutting tool 42 may occur.

If a synchronization error occurs, waviness due to the tooth trace error will occur in the workpiece W to be machined, and there is a possibility that gear machining accuracy will deteriorate. Therefore, when controlling the rotation speed V1 of the workpiece W and the rotation speed V2 of the gear cutting tool 42 according to the variation condition Nwj, the control device 100 controls the rotation speed V1 of the workpiece W and the rotation speed V2 of the gear cutting tool 42 based on the first moment of inertia and the second moment of inertia of the first rotating body. Then, the correction amount of the rotational speed V1 is calculated.

Specifically, the control device 100 controls the difference Iw between the first moment of inertia of the first rotating body and the second moment of inertia of the second rotating body, and the rotational speed of the gear cutting tool 42, that is, the rotating main shaft 40. Based on the rotational speed fluctuation width At of V2 and the rotational speed fluctuation frequency fh, a correction amount ΔAw of the rotational speed fluctuation width of the workpiece W expressed by the following equation 1 is determined. Here, Cwt in the following formula 1 is a constant related to the workpiece W based on the gear cutting tool 42, and is stored in advance. Note that it is also possible to obtain the correction amount ΔAw using a similar variable using a formula using trigonometric functions.

Returning to FIG. 6, when the gear machining device 1 is machining a gear on the workpiece W according to the variable condition Nwj (any of the first variable condition Nwj1 to the third variable condition Nwj3) determined in step S12, S16, or S17, the variable condition setting unit 120 executes the step processing of step S19 of the gear machining processing program. As a result, the variable condition setting unit 120 determines whether the amplification of regenerative chatter vibrations occurring in the workpiece W is suppressed.

That is, if the amplification of the regenerative chatter vibration generated in the workpiece W is suppressed, the variable condition setting unit 120 judges "Yes" in step S19 to continue machining as is and proceeds to step S21. On the other hand, if the amplification of the regenerative chatter vibration generated in the workpiece W is not suppressed, the variable condition setting unit 120 judges "No" in step S19 and proceeds to step S20. In step S20, the variable condition setting unit 120 adjusts and reduces (decreases) the amount of cut in order to reduce the regenerative chatter vibration by lowering the cutting resistance. Then, with the amount of cut in adjusted and reduced, the variable condition setting unit 120 again executes the step processing of steps S18 and S19 to machine a gear on the workpiece W.

Incidentally, when the fluctuation condition setting unit 120 determines "No" in step S19, the fluctuation condition setting unit 120 stores the data in the step S12, S16, or S17 in a storage device (not shown) provided in the control device 100 (database not shown). The fluctuation condition Nwj (any one of the first fluctuation conditions Nwj1 to third fluctuation Nwj3) determined in step 1 and the magnitude of the regenerative chatter vibration are stored. Then, the variation condition setting unit 120 makes the information stored in the storage device (database) usable in the simulation performed by the simulation calculation unit 121 in step S11. Thereby, the accuracy of the simulation of the stability limit increase rate (stability limit) performed by the simulation calculation unit 121 can be improved.

In step S21, the state value determining unit 122 determines whether the production number Np is larger than the reference value Sn3. That is, the state value determination unit 122 determines "No" if the production number Np is less than or equal to the reference value Sn3, and executes each step process from step S13 described above. On the other hand, if the production number Np is larger than the reference value Sn3, the state value determining unit 122 determines "Yes" in step S21 and proceeds to step S22. Then, the variation condition setting unit 120 ends the execution of the gear processing program upon completion of cutting in step S22.

(3. Effect of this example)
As can be understood from the above explanation, according to the gear processing apparatus 1, the variation condition Nwj is set to any one of the first variation condition Nwj1 to the third variation condition Nwj3 according to the production number Np which is the state value. It can be changed in stages. As a result, the power consumption of the gear processing device 1, which can change the variable condition Nwj according to the production quantity Np, can be made uniform without changing the excessive variable condition Nwj (third variable condition Nwj3) in lot production. The power consumption can be reduced compared to when applied to Furthermore, by changing the variable conditions Nwj according to the production number Np, chatter vibration (processing vibration) can be suppressed even when the gear cutting tool 42 is heavily worn, and as a result, the surface texture It is possible to produce good workpieces.

For example, as shown by the broken line in Fig. 9 (including triangle marks), if the third variation condition Nwj3 is fixed from the start of machining, the occurrence of chatter vibration is always suppressed, so normal operation is achieved without causing defects. It is possible to produce a workpiece W that is However, in this case, as shown by the broken line (including the triangle mark) in FIG. 10, the workpiece W is machined in a state where the power consumption is always large. In addition, the thick line shown in FIG. 9 shows the control value for determining the quality of the workpiece W regarding chatter vibration (processing vibration).

On the other hand, especially at the start of machining, the blade 42a of the gear cutting tool 42 is not worn, and chatter vibration is less likely to occur. Therefore, as shown by the solid line in FIG. 9 (including circles), in the initial stage of machining when the production quantity Np is less than the reference value Sn1, the workpiece W is machined under the first fluctuation condition Nwj1 with a small rotational speed fluctuation width. . Thereby, as shown by the solid line (including circles) in FIG. 10, the power consumption can be significantly reduced compared to the case where the workpiece W is machined under the third variation condition Nwj3.

Further, as the production number Np increases, wear etc. begin to occur on the blade 42a of the gear cutting tool 42, and chatter vibration begins to occur. Therefore, as shown in FIG. 9, in the middle stage of machining when the production quantity Np is greater than the reference value Sn1 and less than the reference value Sn2, the machining is performed under the second variation condition Nwj2 in which the rotational speed variation width is greater than the first variation condition Nwj1. Process object W. Thereby, as shown in FIG. 10, the amount of power consumption can be reduced compared to the case where the workpiece W is machined under the third variation condition Nwj3.

When the production number Np further increases, wear and the like occur on the blade 42a of the gear cutting tool 42, causing chatter vibration. Therefore, as shown in FIG. 9, at the end of machining when the production quantity Np is larger than the reference value Sn2 and less than the reference value Sn3, the rotational speed fluctuation width is larger than the second fluctuation condition Nwj2, and the machining is performed under the third fluctuation condition Nwj3. Process object W. As a result, as shown in FIG. 10, power consumption increases at the final stage of processing. However, since the power consumption can be reduced in the initial and middle stages of machining, the total power consumption including the final stage of machining is as follows: This can be reduced compared to the case where

(4. First alternative example)
In this example described above, the variation condition changing unit 123 changes the rotational speed variation width according to the first variation condition Nwj1 to the third variation condition Nwj3, as shown in Table 1. Alternatively, as shown in Table 2 below, the fluctuation condition changing unit 123 can also change the rotational speed fluctuation frequency (rotational speed fluctuation period).

Here, the fourth fluctuation condition Nwj4 is a fluctuation condition Nwj in which the rotational speed fluctuation width is set to 5% and the rotational speed fluctuation frequency is set to 1Hz, similar to the first fluctuation condition Nwj1 of this example described above. It is. Further, the fifth fluctuation condition Nwj5 is a fluctuation condition Nwj in which the rotational speed fluctuation width is set to 5% and the rotational speed fluctuation frequency is set to 2Hz. Furthermore, the sixth fluctuation condition Nwj6 is a fluctuation condition Nwj in which the rotation speed fluctuation width is set to 5% and the rotation speed fluctuation frequency is set to 3 Hz. That is, in the fourth variation condition Nwj4 to the sixth variation condition Nwj6 in the first alternative example, the rotational speed variation width is 5% and is not changed, and only the rotational speed variation frequency is changed.

Here, as shown in FIG. 11, the estimated stability limit (depth of cut) becomes larger when there is a frequency fluctuation in the rotational speed than when there is no frequency fluctuation in the rotational speed, and It is estimated that there is a relationship that increases as the value increases. In this first alternative example as well, similarly to the present example described above, the variable conditions Nwj are changed as appropriate according to the production quantity Np by executing the gear processing program shown in the flowchart shown in FIG. be able to. Therefore, the same effects as in this example described above can be expected.

(5. Second alternative example)
In this example described above, the variation condition changing unit 123 changes the variation condition Nwj to any one of the first variation condition Nwj1 to the third variation condition Nwj3 so as to change only the rotational speed variation width. Further, in the first alternative example described above, the fluctuation condition changing unit 123 changes the fluctuation condition Nwj to the fourth fluctuation condition Nwj4 to the sixth fluctuation condition Nwj6 so as to change only the rotational speed fluctuation frequency (rotational speed fluctuation period). I changed it to . However, changing the fluctuation condition Nwj is not limited to changing only the rotation speed fluctuation width or changing only the rotation speed fluctuation frequency (rotation speed fluctuation period).

That is, the fluctuation condition changing unit 123 can also change both the rotational speed fluctuation width and the rotational speed fluctuation frequency at the same time according to the state value. In this way, when changing both the rotational speed fluctuation width and the rotational speed fluctuation frequency at the same time, it becomes possible to set the fluctuation conditions Nwj more precisely. As a result, it is possible to achieve energy savings while ensuring machining efficiency.

(6. Third alternative example)
In this example, the first alternative example, and the second alternative example described above, at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency is changed according to the first fluctuation condition Nwj1 (fourth fluctuation condition Nwj4) from the start of machining the workpiece W. I made it variable. Here, at the start of machining, the possibility that chatter vibration will occur due to machining is extremely small compared to when the production number Np increases. Therefore, as shown in Table 3 below, which illustrates the case of this example described above, until the production number Np reaches the reference value Sn0, the rotational speed fluctuation range is not varied, and the rotational speed fluctuation frequency is also It is also possible to apply initial conditions that are not varied. Note that the reference value Sn0 is set to be smaller than the reference value Sn1.

The gear machining program in this third example is modified as shown in the flowchart of FIG. Specifically, in the gear machining program in the third alternative example, step S12 in the gear machining program shown in FIG. 6 is changed to step S30, and step S31 and step S32 are added.

In this case, the variation condition changing unit 123 sets an initial condition as a variation condition Nwj when the production number Np of workpieces W is less than the reference value Sn0 in step S30. That is, in the third alternative example, the variation condition changing unit 123 sets, as the variation condition Nwj, an initial condition in which the rotational speed variation width and the rotational speed variation frequency are not varied, as shown in Table 3. After the variation condition setting unit 120 (variation condition changing unit 123) sets the variation condition Nwj as the initial condition, the process proceeds to step S31.

In step S31, the state value determining unit 122 obtains the production number Np, which is the state value of the workpiece W by the gear processing device 1, and determines whether the production number Np is larger than the reference value Sn0. That is, if the production number Np is larger than the reference value Sn0, the state value determining unit 122 determines "Yes" and proceeds to step S14. On the other hand, if the production number Np is less than or equal to the reference value Sn0, the state value determining unit 122 determines "No" and proceeds to step S18. In this case, the gear processing device 1 performs gear processing on the workpiece W according to the initial conditions, that is, without changing the rotational speed fluctuation width and rotational speed fluctuation frequency of the rotational speed V1 of the workpiece W.

Then, the fluctuation condition changing unit 123 determines that if the production number Np is less than or equal to the reference value Sn1 (the production number Np is greater than the reference value Sn0 and less than or equal to the reference value Sn1), the state value determination unit 122 determines that the production quantity Np is less than or equal to the reference value Sn1. case), the step process of step S32 is executed. That is, in step S32, the variation condition changing unit 123 changes the variation condition Nwj from the initial condition to the first variation condition Nwj1 (fourth variation condition Nwj4). Then, after changing the fluctuation condition Nwj from the initial condition to the first fluctuation condition Nwj1 (fourth fluctuation condition Nwj4), the fluctuation condition setting unit 120 (variation condition changing unit 123) proceeds to step S18.

Accordingly, in the third example, when the production number Np becomes larger than the reference value Sn0, the variation condition changing unit 123 changes the variation condition Nwj to the first variation condition Nwj1 (fourth variation condition Nwj4). Therefore, as described above, the amount of power consumed under the initial condition without any variation is smaller than the amount of power consumed under the first variation condition Nwj1 (fourth variation condition Nwj4), making it possible to achieve greater energy savings.

(7. Fourth alternative example)
In this example and the first to third different examples described above, by determining the production number Np which is a state value, the fluctuation condition changing unit 123 changes the fluctuation condition Nwj according to the determined production number Np. The variation condition is changed to any one of the first variation condition Nwj1 to the third variation condition Nwj3 (or/and the fourth variation condition Nwj4 to the sixth variation condition Nwj6). Here, the state value represents the machining state of the workpiece W by the gear cutting tool 42 regarding machining of the workpiece W, so current value (amount of wear), vibration, and tooth trace error (surface texture) may be used. I can do it.

The current value represents the magnitude of the current required to rotate and feed the gear cutting tool 42, and is a state value that can be detected, for example, by a current sensor (not shown) provided on the spindle motor 41, the table motor 62, etc. The current value increases when the amount of wear on the blade 42a of the gear cutting tool 42 increases with an increase in the production number Np, resulting in an increase in machining resistance. In other words, the current value is a detectable state value that can reflect the amount of wear on the blade 42a of the gear cutting tool 42 and the change in machining resistance that occurs during machining by the gear cutting tool 42.

The vibration is a state value that can be detected by, for example, an acceleration sensor (not shown) disposed on the rotating main shaft 40, the bed 10, or the like. In particular, when the chatter vibration frequency matches the chatter vibration frequency, it is possible to directly detect the occurrence of chatter vibration by detecting the vibration generated in the rotating main shaft 40, bed 10, etc. due to the occurrence of chatter vibration. can. Here, instead of detecting vibration using an acceleration sensor, it is also possible to detect sound using, for example, a microphone placed in the processing area. That is, by detecting sound having the chatter vibration frequency of the chatter vibration with the microphone, the occurrence of chatter vibration can be directly detected.

The tooth trace error represents the surface quality of the teeth of the workpiece W formed by the gear cutting tool 42, and is a state value that can be detected by, for example, a shape measuring machine or a roughness meter (both not shown). The tooth trace error increases when the amount of wear on the blade 42a of the gear cutting tool 42 increases as the production number Np increases. That is, the tooth trace error is a detectable state value and can reflect a change in the amount of wear of the blade 42a of the gear cutting tool 42.

In the fourth alternative example, the state value determination unit 122 determines the above-mentioned current value (wear amount and machining resistance of the gear cutting tool 42), frequency of vibration (sound), tooth trace error (surface texture of the workpiece W), ) is obtained as the state value K, and the state value K is compared with a preset determination value H. Then, as shown in FIG. 13, each time the state value K (the magnitude of machining vibration in FIG. 13) exceeds the judgment value H indicated by the long broken line, the variation condition changing unit 123 changes the variation condition Nwj to the first variation. It is maintained or changed to any one of the condition Nwj1 to the third variation Nwj3 (or/and the fourth variation condition Nwj4 to the sixth variation condition Nwj6).

The gear processing program in this fourth alternative example is changed from the flowchart shown in FIG. 6, as shown in the flowchart of FIG. Specifically, in the gear machining program in the fourth alternative example, step S14 and step S15 in the gear machining program shown in FIG. 6 are omitted, and step S13 and step S21 are replaced with step S40 and step S21, respectively. Step S44 is changed, and step S41, step S42, and step S43 are further added.

In this case, when the variation condition changing unit 123 sets the variation condition Nwj to the first variation condition Nwj1 (fourth variation condition Nwj4) in step S12, the state value determination unit 122 changes the above-mentioned sensor in step S40. For example, a state value K representing vibration (processing vibration) obtained from an acceleration sensor is obtained. Then, the state value determination unit 122 executes the subsequent step process of step S41.

In step S41, the state value determination unit 122 determines whether the state value K acquired in step S40 is larger than the determination value H. That is, if the state value K is larger than the determination value H, the state value determination unit 122 determines "Yes" and proceeds to step S42. On the other hand, if the state value K is equal to or less than the determination value H in step S41, the state value determination unit 122 determines "No" and proceeds to step S18. In this case, the gear processing device 1 performs gear processing on the workpiece W by varying the rotation speed V1 of the workpiece W according to the first variation condition Nwj1 (fourth variation condition Nwj4).

In step S42, the state value determination unit 122 adds "1" to a count value A representing the number of times the state value K exceeds the determination value H. Note that the initial value of the count value A is set to "0" by a reset process at the start of execution of the gear processing program. After the state value determination unit 122 adds "1" to the count value A, the process proceeds to step S43.

In step S43, the state value determination unit 122 determines whether the count value A added by "1" in step S42 is "1". That is, if the count value A is "1", the state value determination unit 122 determines "Yes" and proceeds to step S16. Thereby, the fluctuation condition changing unit 123 changes the fluctuation condition Nwj from the first fluctuation condition Nwj1 (fourth fluctuation condition Nwj4) to the second fluctuation condition Nwj2 (fifth fluctuation condition Nwj5).

On the other hand, the state value determination unit 122 determines that when the state value K exceeds the determination value H twice (see FIG. 13), the count value A is not "1", that is, the count value A is "2". ”, the determination is “No” in step S43, and the process proceeds to step S17. Thereby, the fluctuation condition changing unit 123 changes the fluctuation condition Nwj from the second fluctuation condition Nwj2 (fifth fluctuation condition Nwj5) to the third fluctuation condition Nwj3 (sixth fluctuation condition Nwj6).

In the fourth alternative example, when the determination process in step S19 yields "Yes", the state value determination unit 122 determines whether the count value A is "3" in step S44. do. That is, the state value determination unit 122 determines that the state value K has not yet exceeded the judgment value H, that the state value K has exceeded the judgment value H once (count value A is "1"), or that the state value K has exceeded the judgment value H. If the determination value H has been exceeded twice (count value A is "2"), the determination is "No" and the process returns to step S40. Then, the variation condition setting unit 120 executes each step processing after step S40.

On the other hand, if the state value K exceeds the determination value H three times (see FIG. 13) and the count value A is "3", the state value determination unit 122 determines "No" and The process advances to step S22. Then, the variation condition setting unit 120 ends the execution of the gear machining processing program. Therefore, in this fourth alternative example, the same effects as in this example and the first to third different examples described above can be obtained.

(8. Fifth alternative example)
In this example and the first to fourth variations described above, the variation condition changing unit 123 changes the variation condition Nwj (first variation condition Nwj1 to third variation condition) in stages based on the determination result of the state value determination unit 122. The variation condition Nwj3 and/or the fourth variation condition Nwj4 to the sixth variation condition Nwj6) are changed. Instead, the fluctuation condition changing unit 123 continuously changes the fluctuation conditions Nwj, that is, the rotation speed fluctuation width and the rotation speed fluctuation frequency (rotation speed fluctuation period), according to the production number Np (state value) and the state value K. It is also possible to change at least one of them.

In this way, when at least one of the rotation speed fluctuation width and the rotation speed fluctuation frequency (rotation speed fluctuation period) is continuously changed, it is possible to set the fluctuation conditions Nwj more precisely. As a result, it is possible to achieve energy savings while ensuring machining efficiency.

(9. Another example of gear processing device 1)
In this example and the first to fourth examples described above, the gear cutting tool 42 is a skiving cutter, and the gear processing apparatus 1 performs gear processing by skiving. On the other hand, when the gear cutting tool 42 is a hob cutter, the gear processing device 1 can perform gear processing by hobbing.

In this case, as shown in FIG. 15, the gear processing device 1 includes a hob cutter gear cutting tool 242. The gear processing device 1 arranges the gear cutting tool 242 and the workpiece W so that the rotation axis O of the gear cutting tool 242 and the C axis, which is the rotational axis of the workpiece W, intersect. In addition, in FIG. 15, the gear cutting tool 242 and the workpiece W are arranged so that the rotational axis O of the gearing tool 242 and the C axis, which is the rotational axis of the workpiece W, are orthogonal to each other.

During gear machining, the gear processing device 1 rotates the workpiece W and the gear cutting tool 242, respectively, and sends the gear cutting tool 242 in the Z-axis direction (relatively moving it), thereby attaching the gear to the workpiece W. Process. At this time, during gear machining, the gear processing device 1 varies the rotational speed V1 of the workpiece W based on control by the workpiece rotational speed control section 130, for example, similarly to the present example described above. Further, during gear machining, the gear processing device 1 changes the rotation speed V2 of the gear cutting tool 242 to the rotation speed of the workpiece W based on the control by the tool rotation speed control section 140, for example, similar to the present example described above. Synchronize with V1.

As a result, the gear machining device 1 can rotate the gear cutting tool 242 at high speed while suppressing the amplification of regenerative chatter vibrations that occur in the workpiece W. Therefore, the gear machining device 1 can simultaneously improve the surface quality of the machined surface formed on the workpiece W and improve the machining efficiency.

(10. Others)
In this example and the first to fourth different examples described above, the simulation calculation unit 121 calculates the stability limit by simulation. Alternatively, the stability limit can be generated using the results of machine learning. In this case, the fluctuation condition setting unit 120 generates a learned model by, for example, using the rotational speed fluctuation range and the rotational speed fluctuation frequency as the training data set and the stability limit as the teacher data. As a result, the variation condition setting unit 120 uses the generated learned model to set appropriate variation conditions Nwj, that is, first variation conditions Nwj1 to third variation conditions Nwj3, or fourth variation conditions Nwj4 to sixth variation conditions Nwj3. A variation condition Nwj6 can be determined.

In addition, in this example and the first to fourth variations described above, the variation condition changing unit 123 changes the variation condition Nwj to any one of the first variation condition Nwj1 to the third variation condition Nwj3, or the fourth variation condition Nwj. The variation condition is changed to any one of the variation condition Nwj4 to the sixth variation condition Nwj6. The number of variable conditions Nwj that can be changed is not limited to three, and can of course be changed to two or four or more.

Furthermore, in this example and the first to fifth different examples described above, the fluctuation frequency of the rotational speed V1 of the workpiece W matches the rotational speed fluctuation frequency (or rotational speed fluctuation period) of the fluctuation condition Nwj. I explained the case. However, the invention is not limited to this, and the rotational speed V1 of the workpiece W may be set to increase or decrease at a fluctuation frequency that is greater than or equal to the rotational speed fluctuation frequency (or rotational speed fluctuation period). .

Further, in this example and the first to fifth different examples described above, the workpiece rotation speed control section 130 repeatedly increases or decreases the rotation speed V1 of the workpiece W, and the tool rotation speed control section 140 increases or decreases the rotation speed V1 of the workpiece W. The case where the rotational speed V2 of the cutting tool 42 is varied in synchronization with the rotational speed V1 of the workpiece W has been described. However, the present invention is not limited to this, and the tool rotation speed control unit 140 repeatedly increases or decreases the rotation speed V2 of the gear cutting tool 42 according to the changed fluctuation condition Nwj, and the workpiece rotation speed control unit 130 controls the rotation speed V2 of the gear cutting tool 42 to The rotational speed V1 of W may be varied while being synchronized with the rotational speed V2 of the gear cutting tool 42.

Furthermore, in this example and the first to fifth alternative examples described above, the case where the feed speed control section 160 varies the feed speed V4 so as to be synchronized with the rotation speed V1 of the workpiece W has been described. However, the feed rate control section 160 does not necessarily need to vary the feed rate V4. That is, the gear processing device 1 varies the rotational speed V1 of the workpiece W and the rotational speed V2 of the gear cutting tool 42 so that at least the rotational speed V1 of the workpiece W and the rotational speed V2 of the gear cutting tool 42 are synchronized. As a result, amplification of chatter vibrations (regenerative chatter, etc.) generated in the workpiece W can be suppressed. Further, the feed speed control section 160 may vary the feed speed V4 irregularly.

1... gear machining device, 10... bed, 11... Y-axis motor, 12... Z-axis motor, 20... column, 30... saddle, 40... rotating spindle, 41... spindle motor, 42... gear cutting tool, 42a... blade, 50... table, 60... tilt table, 61... tilt table support, 62... table motor, 70... turntable, 80... holder, 100... control device, 110... reference rotation speed setting unit, 120... variable condition setting unit, 121... simulation calculation unit, 122... state value determination unit, 123... variable condition Change unit, 130... workpiece rotation speed control unit, 140... tool rotation speed control unit, 150... reference feed speed setting unit, 160... feed speed control unit, 242... gear cutting tool, Fw... reference feed speed, Nw... reference rotation speed, Nwj, Nwj1, Nwj2, Nwj3, Nwj4, Nwj5, Nwj6... variable conditions, Np... production number (state value), K... state value, O... rotation axis, V1... workpiece rotation speed, V2... gear cutting tool rotation speed, V3... cutting speed, V4... feed speed, W... workpiece, γ... rake angle, δ... cross angle

Claims (14)

a control device that controls synchronous rotation of the gear cutting tool and the workpiece and controls relative movement between the gear cutting tool and the workpiece along the rotational axis direction of the workpiece; A gear processing device that processes
The control device includes:
A rotational speed fluctuation range representing a fluctuation range when varying the rotational speed of the synchronous rotation according to a state value representing a processing state of the workpiece by the gear cutting tool regarding machining of the workpiece, and the rotational speed a fluctuation condition changing unit that changes at least one of the rotational speed fluctuation frequencies representing the frequency when changing the rotational speed ;
The rotational speed of the synchronous rotation of the gear cutting tool and the workpiece is controlled to vary based on at least one of the rotational speed fluctuation range and the rotational speed fluctuation frequency changed by the fluctuation condition changing unit, and the rotational speed of the synchronous rotation of the gear cutting tool and the workpiece is controlled A gear processing device, comprising: a control unit that fluctuates and controls the feed rate of the relative movement between the gear cutting tool and the workpiece so as to synchronize with the rotational speed of the rotation . a control device that controls synchronous rotation of the gear cutting tool and the workpiece and controls relative movement between the gear cutting tool and the workpiece along the rotational axis direction of the workpiece; A gear processing device that processes
The control device includes:
A rotational speed fluctuation range representing a fluctuation range when varying the rotational speed of the synchronous rotation according to a state value representing a processing state of the workpiece by the gear cutting tool regarding machining of the workpiece, and the rotational speed comprising a fluctuation condition changing unit that changes at least one of the rotational speed fluctuation frequencies representing the frequency at which the rotational speed fluctuation frequency is varied ;
The variation condition changing unit determines whether to change or maintain at least one of the rotational speed fluctuation range and the rotational speed fluctuation frequency based on a balance between machining efficiency and energy saving. The control device further includes:
The rotational speed of the synchronous rotation of the gear cutting tool and the workpiece is controlled to vary based on at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency changed by the fluctuation condition changing unit, and the rotational speed of the synchronous rotation of the gear cutting tool and the workpiece is controlled The gear processing device according to claim 2, further comprising a control unit that fluctuates and controls the feed rate of the relative movement between the gear cutting tool and the workpiece so as to be synchronized with the rotational speed of the rotation. The gear processing apparatus according to any one of claims 1 to 3, wherein the fluctuation condition changing section keeps the rotational speed fluctuation frequency constant and changes the rotational speed fluctuation width. The gear processing apparatus according to any one of claims 1 to 4 , wherein the state value is the number of the workpieces produced by the gear cutting tool. The state value includes a current value representing a current for driving the workpiece and the gear cutting tool, vibrations generated due to machining by the gear cutting tool, the amount of wear caused by the gear cutting tool, and The gear processing apparatus according to any one of claims 1 to 4, wherein the surface texture of the processed surface of the workpiece is any one of the following. The state value includes the number of workpieces produced by the gear cutting tool, a current value representing a current for driving the workpiece and the gear cutting tool, vibrations generated due to machining by the gear cutting tool, and the Either the amount of wear caused by the gear cutting tool or the tooth trace error on the machined surface of the workpiece,
Any one of claims 1 to 4, wherein the fluctuation condition changing unit changes at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency to a larger value in response to an increase in the state value. The gear processing device described in . The control device further includes:
a state value determination unit that acquires the state value and determines whether or not the state value is larger than a plurality of reference values set to different values in advance;
Any one of claims 1 to 7 , wherein the fluctuation condition changing unit changes at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency in a stepwise manner according to a determination result by the state value determination unit. The gear processing device according to item 1. The control device further includes:
comprising a state value determination unit that acquires the state value and determines whether the state value is larger than a preset reference value;
According to any one of claims 1 to 7 , the fluctuation condition changing unit changes at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency according to a determination result by the state value determination unit. The gear processing device described. Gear processing in which a gear is machined on the workpiece by moving the gear cutting tool relative to the workpiece along the rotational axis direction of the workpiece while rotating the gear cutting tool and the workpiece synchronously. A method,
acquiring a state value representing a machining state of the workpiece by the gear cutting tool regarding machining of the workpiece, and determining whether or not the state value is larger than a preset reference value;
A rotational speed fluctuation range representing a fluctuation range when the rotational speed of the synchronous rotation is varied, and a frequency when the rotational speed is varied in accordance with a determination result that the state value is larger than a preset reference value. change at least one of the rotational speed fluctuation frequencies representing
Variably controlling the rotational speed of the synchronous rotation in the gear cutting tool and the workpiece based on at least one of the changed rotational speed fluctuation width and the rotational speed fluctuation frequency, and synchronizing with the rotational speed of the synchronous rotation. A gear machining method , wherein the feed speed of the relative movement between the gear cutting tool and the workpiece is variably controlled so as to perform the following steps . Gear processing in which a gear is machined on the workpiece by moving the gear cutting tool relative to the workpiece along the rotational axis direction of the workpiece while rotating the gear cutting tool and the workpiece synchronously. A method,
acquiring a state value representing a machining state of the workpiece by the gear cutting tool regarding machining of the workpiece, and determining whether or not the state value is larger than a preset reference value;
A rotational speed fluctuation range representing a fluctuation range when the rotational speed of the synchronous rotation is varied, and a frequency when the rotational speed is varied in accordance with a determination result that the state value is larger than a preset reference value. change at least one of the rotational speed fluctuation frequencies representing
A gear machining method that determines whether to change or maintain at least one of the rotational speed fluctuation width and the rotational speed fluctuation frequency based on a balance between machining efficiency and energy saving . Variably controlling the rotational speed of the synchronous rotation in the gear cutting tool and the workpiece based on at least one of the changed rotational speed fluctuation width and the rotational speed fluctuation frequency, and synchronizing with the rotational speed of the synchronous rotation. 12. The gear machining method according to claim 11, wherein the feed speed of the relative movement between the gear cutting tool and the workpiece is controlled to be variable. The gear processing method according to any one of claims 10 to 12 , wherein the state value is the number of production of the workpiece by the gear cutting tool. The state value includes a current value representing a current for driving the workpiece and the gear cutting tool, vibrations generated due to machining by the gear cutting tool, the amount of wear caused by the gear cutting tool, and The gear machining method according to any one of claims 10 to 12, which is any one of the surface textures of the machined surface of the workpiece.

Images