JP6500486B2 - Gear processing apparatus and gear processing method - Google Patents

Description

  The present invention relates to a gear machining apparatus and a gear machining method for machining a gear by rotating a machining tool and a workpiece in synchronization and cutting.

  As an effective apparatus which processes internal teeth and external teeth, such as a helical gear, by cutting, there exists a processing apparatus of patent document 1, for example. The processing apparatus comprises: a workpiece rotatable about an axis of rotation; and a processing tool rotatable about an axis of rotation inclined at a predetermined angle with respect to the axis of rotation of the workpiece, that is, about an axis of rotation having a crossing angle. For example, it is a processing device that generates teeth by synchronously rotating with a cutter having a plurality of tool blades in which blade lines are twisted and sending a processing tool in the rotation axis direction of a workpiece for cutting. Patent Document 2 describes that in the internal gear machining, the position and the rotation of the machining tool are determined to set the crossing angle.

Unexamined-Japanese-Patent No. 1-159126 Patent No. 4468632 gazette

Generally, the twist angle of the blade line of the tool blade of the above-described processing tool is represented by the difference between the twist angle of the gear (workpiece) and the crossing angle. Usually, since the crossing angle is set within the range of 10 degrees to 30 degrees, for example, when the twist angle of the gear is 20 degrees and the crossing angle is 17 degrees, the twist angle of the blade edge of the tool blade is 3 Degree. Then, generally, as shown in FIG. 4B, with respect to a straight line parallel to the rotation axis Lw of the workpiece W, the twist angle θ of the gear G inclined, the rotation axis Lw of the workpiece W, and the processing tool 92 Design the processing tool 92 with the difference between it and the rotation axis L as the twist angle β ′ (= θ−φ) of the blade streak 92b of the tool blade 92a (the twist angle β ′ in FIG. 4B is a process) This represents the angle at the processing point of the processing tool 92 located on the near side in the drawing of the object W). However, in the processing tool 92, the twist angle β 'of the tool blade 92a becomes smaller, and the width of the cutting edge of the tool blade 92a also becomes smaller. There is.

The present invention has been made in view of such circumstances, gear cutting can be suppressed chatter vibration at the time of processing the rehearsal vehicle by the cutting using a machining tool to form a tool blade tool end surface It aims at providing an apparatus and gear processing method.

Gear machining apparatus of the present invention, with respect to the rotational axis of the workpiece, using a machining tool having an axis of rotation inclined by crossing angle, a gear machining apparatus for machining a gear before Symbol workpiece, a storage unit The control device includes a tool design unit and a processing control unit, the storage unit stores the crossing angle, the number of blades of the processing tool, and the twist angle of the gear, and the tool design unit is configured to twist the gear. The angle obtained by adding the intersection angle to the angle is calculated as the twist angle of the edge of the tool edge of the processing tool, and the width of the edge of the tool edge is determined based on the number of edges and the angle of twist of the edge. The shape of the processing tool is determined based on the number of blades, the twist angle of the blade line, and the cutting edge width, and the processing control unit determines the processing tool whose shape is determined by the tool design unit. Rotation axis direction of the workpiece while rotating in synchronization with Relatively feeding operations to processing the gears.

  As a result, the twist angle of the blade edge of the tool blade is increased, and the blade width of the tool blade is also increased. Therefore, since it is easy to deform a blade edge at the time of processing, generation of chatter vibration can be suppressed and processing accuracy can be improved.

The gear machining method of the present invention has a rotation axis inclined by a crossing angle with respect to the rotation axis of the workpiece, and a cutting tool formed by twisting a blade edge of the tool blade with respect to the inclined rotation axis. A gear machining method for machining a gear by using a blade number setting step of setting the number of blades of the tool blade, and calculating an angle obtained by adding the crossing angle to a twist angle of the gear as a twist angle of the blade. The blade width calculating step of calculating the blade width of the tool blade based on the twist angle calculating step, the blade number set as described above, and the obtained twist angle, and the blade width obtained as described above A tool determination step of determining the shape of the processing tool based on the twist angle of the blade line and the set number of blades, and the rotation axis of the workpiece while synchronously rotating the determined processing tool with the workpiece Feed operation relative to the direction And a processing step of processing the gears.
Thereby, the same effect as the effect in the gear machining device described above is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the gear processing apparatus which concerns on embodiment of this invention. It is a flowchart for demonstrating the process by the control apparatus of the gear processing apparatus of FIG. It is the figure which looked at schematic structure of the tool for processing from the tool end surface side in the rotation axis direction. It is a fragmentary sectional view which looked at the schematic structure of the processing tool of FIG. 3A in radial direction. It is an enlarged view of the tool blade of the processing tool of FIG. 3B. It is a figure which shows the positional relationship of the processing tool at the time of processing with the processing tool of FIG. 3A, and a workpiece. It is a figure which shows the positional relationship of the processing tool at the time of processing with a common processing tool, and a workpiece. It is a figure which shows each site | part of the processing tool used when calculating | requiring the blade-tip width | variety of the processing tool.

(Machine configuration of gear processing device)
In the present embodiment, a 5-axis machining center will be described as an example of a gear machining device, with reference to FIG. That is, the said gear processing apparatus 1 is an apparatus which has three rectilinear axes (X, Y, Z axis | shaft) and two rotation axes (A axis | shaft, C axis | shaft) which mutually orthogonally cross as a drive shaft.

  As shown in FIG. 1, the gear machining device 1 includes a bed 10, a column 20, a saddle 30, a rotating spindle 40, a table 50, a tilt table 60, a turntable 70, and a workpiece holder 80. , And the control device 100 and the like. Although not shown, a known automatic tool changer is provided alongside the bed 10.

  The bed 10 has a substantially rectangular shape and is disposed on the floor. An unillustrated X-axis ball screw for driving the column 20 in the X-axis direction is disposed on the upper surface of the bed 10. The bed 10 is provided with an X-axis motor 11 c that rotationally drives an X-axis ball screw.

  On a side surface (sliding surface) 20a parallel to the Y axis of the column 20, a Y axis ball screw (not shown) for driving the saddle 30 in the Y axis direction is disposed. The column 20 is provided with a Y-axis motor 23c that rotationally drives a Y-axis ball screw.

The rotating spindle 40 supports the processing tool 42, is rotatably supported in the saddle 30, and is rotated by a spindle motor 41 housed in the saddle 30. The processing tool 42 is held by a tool holder (not shown) and fixed to the tip of the rotating spindle 40, and rotates as the rotating spindle 40 rotates. Further, the processing tool 42 moves in the X axis direction and the Y axis direction with respect to the bed 10 as the column 20 and the saddle 30 move. The details of the processing tool 42 will be described later.

  Further, on the upper surface of the bed 10, a Z-axis ball screw (not shown) for driving the table 50 in the Z-axis direction is disposed. Then, in the bed 10, a Z-axis motor 12c that rotationally drives a Z-axis ball screw is disposed.

  A tilt table support 63 for supporting the tilt table 60 is provided on the top surface of the table 50. The tilt table 60 is provided on the tilt table support 63 so as to be rotatable (oscillating) around an A axis parallel to the X axis. The tilt table 60 is rotated (rocked) by an A-axis motor 61 accommodated in the table 50.

  The turntable 70 is provided on the tilt table 60 so as to be rotatable about a C-axis perpendicular to the A-axis. A workpiece holder 80 for holding the workpiece W is mounted on the turn table 70. The turntable 70 is rotated by the C-axis motor 62 together with the workpiece W and the workpiece holder 80.

  The control device 100 includes a tool design unit 101, a processing control unit 102, a storage unit 103, and the like. Here, the tool design unit 101, the processing control unit 102, and the storage unit 103 can be configured by individual hardware, or can be configured to be realized by software.

Tool design unit 101, which will be described in detail later, to design a helix angle β machining tools 42 seeking (Figure 3 C reference) or the like of the tool blades 42a of the working tool 42.
The processing control unit 102 controls the spindle motor 41 to rotate the processing tool 42, and controls the X-axis motor 11c, the Z-axis motor 12c, the Y-axis motor 23c, the A-axis motor 61, and the C-axis motor 62. The workpiece W is cut by relatively moving the workpiece W and the processing tool 42 in the X axis direction, the Z axis direction, the Y axis direction, around the A axis, and around the C axis.

  The storage unit 103 stores the number of blades Z of the tool blade 42 a and the crossing angle φ input when designing the processing tool 42. In the storage unit 103, tool data relating to the processing tool 42, that is, a tip diameter circle da, a reference circle diameter d, a tip end ha, a module m, a dislocation coefficient λ, a pressure angle α, a front pressure angle αt, and a tip The pressure angle αa and processing data for cutting the workpiece W are stored in advance.

(Tool for processing)
In the above-described gear machining device 1, the machining tool 42 and the workpiece W are synchronously rotated, and the machining tool 42 is sent in the direction of the rotation axis of the workpiece W for cutting, thereby creating teeth. As shown in FIG. 3A, when the processing tool 42 is viewed from the side of the tool end surface 42A in the direction of the rotation axis L, the shape of the tool blade 42a is the shape of the teeth meshing with the gear to be processed. It is formed in the same shape.

Then, as shown in FIG. 3B, the tool edge 42a of the processing tool 42 is provided with a rake angle inclined at an angle γ with respect to a plane perpendicular to the rotation axis L on the tool end surface 42A side. With respect to a straight line parallel to the rotation axis L, a front clearance angle inclined by an angle δ is provided. Then, as shown in FIG. 3C, a blade line 42b extending in a direction substantially perpendicular to the blade surface of the tool blade 42a has a twist angle inclined at an angle β with respect to a straight line parallel to the rotation axis L.

Here, as described in the background art, generally, as shown in FIG. 4B, a twist angle θ of the gear G inclined with respect to a straight line parallel to the rotation axis Lw of the workpiece W (hereinafter referred to as “workpiece The difference between the twist angle θ of W), the crossing angle φ of the axis of rotation Lw of the workpiece W and the axis of rotation L of the processing tool 92, the twist angle β ′ of the cutting edge 92b of the tool blade 92a (= The processing tool 92 is designed as θ−φ) (the twist angle β ′ in FIG. 4B represents the angle at the processing point of the processing tool 92 located on the near side of the workpiece W in the drawing ). However, in the processing tool 92, the twist angle β 'of the tool blade 92a becomes smaller, and the width of the cutting edge of the tool blade 92a also becomes smaller. There is.

Therefore, in the present embodiment, the twist angle β of the blade line 42b of the tool blade 42a is increased, and the blade width of the tool blade 42a is also increased. For this reason, as shown in FIG. 4A, the processing tool 42 is designed with the sum of the twist angle θ of the workpiece W and the crossing angle φ as the twist angle β (= θ + φ) of the blade stripe 42b of the tool blade 42a (FIG. 4A) The twist angle β of 4A represents the angle at the processing point of the processing tool 42 located on the near side of the workpiece W in the drawing ). 4A and 4B are diagrams seen from the radial direction passing through the processing point of the workpiece W in a state where the processing tools 42 and 92 are located on the front side of the workpiece W, that is, the rotation axis of the workpiece W It is a view seen from a straight direction perpendicular to Lw and passing the processing point, and the crossing angle φ is a plane perpendicular to the above-mentioned straight line between the rotation axis Lw of the workpiece W and the rotation axis L of the processing tool 92 It is a corner when projected.

An example of calculation for obtaining the blade width will be described below.
As shown in FIG. 5, the cutting edge width Sa of the tool blade 42 a is represented by a half radius Ψa of a cutting edge circle diameter da and a cutting edge circular thickness (see equation (1)).

  The cutting edge circle diameter da is represented by a reference circle diameter d and a cutting edge ha (see equation (2)). Furthermore, the reference circle diameter d is the number Z of the tool blade 42a, and the blade streak 42b of the tool blade 42a. And a module m (see equation (3)), and a blade end ha is represented by a dislocation coefficient λ and a module m (see equation (4)).

  Further, the half-angle は a of the cutting edge circular thickness is represented by the number of cutting edges Z of the tool blade 42a, the dislocation coefficient λ, the pressure angle α, the front pressure angle αt, and the cutting edge pressure angle αa (see equation (5)). The front pressure angle αt can be expressed by the pressure angle α and the twist angle β of the blade 42b of the tool blade 42a (refer to equation (6)), and the blade pressure angle αa is the front pressure angle αt and the blade circle diameter It can be represented by da and a reference circle diameter d (see equation (7)).

  When it is assumed that the cutting edge circle diameter da of the processing tool 42 of the present embodiment is the same as the cutting edge circle diameter of the conventional processing tool 92, as is apparent from the equations (5) to (7) As the twist angle β of the blade 42b of 42a increases, cos β decreases, so the half-angle Ψa of the blade edge circular thickness increases. Therefore, as is clear from the equation (1), the cutting edge width Sa of the tool blade 42a becomes large.

  Specifically, for example, the number of blades Z, the dislocation coefficient λ, and the module m of the conventional processing tool 92 and the processing tool 42 of this embodiment are the same, the twist angle θ of the workpiece W is 20 degrees, and the crossing angle When φ is 17 degrees, the twist angle β ′ of the blade streak 92b of the tool blade 92a of the conventional processing tool 92 is 3 degrees, so the blade width of the tool blade 92a is obtained by Equations (1) to (7) Sa is 0.16 mm. On the other hand, the twist angle β of the blade stripe 42b of the tool blade 42a of the processing tool 42 according to the present embodiment is 37 degrees, so that the blade width Sa of the tool blade 42a is 0. It becomes 3 mm, and it becomes larger than 0.16 mm of blade-edge widths of the tool blade 92a of the conventional processing tool 92.

(Processing by control device)
Next, the process of the control device 100 will be described with reference to FIG. The data on the processing tool 42, that is, the edge diameter da, the reference circle diameter d, the end edge ha, the module m, the dislocation coefficient λ, the pressure angle α, the front pressure angle αt, and the edge pressure angle αa It is assumed that it is stored in advance in 103.

  The tool design unit 101 of the control device 100 stores the number of blades Z of the tool blade 42a of the processing tool 42 input by the worker in the storage unit 103 (step S1 in FIG. 2, the number of blades setting process). Then, the tool design unit 101 stores in the storage unit 103 the crossing angle φ between the rotation axis Lw of the workpiece W input by the operator and the rotation axis L of the processing tool 42, and based on this crossing angle φ The twist angle β of the blade line 42b of the tool blade 42a of the processing tool 42 is determined (Step S2 in FIG. 2, a twist angle calculation step).

  The tool design unit 101 obtains the cutting edge width Sa of the tool blade 42a based on the stored number of blades Z and the obtained twist angle β (Step S3 in FIG. 2, cutting edge width calculation step). Then, the tool design unit 101 reads the threshold value SS of the cutting edge width Sa stored in advance from the storage unit 103, and determines whether the obtained cutting edge width Sa is equal to or greater than the threshold value SS (step S4 in FIG. 2). .

  When the obtained blade width Sa is less than the threshold value SS, the tool design unit 101 returns to step S1 to repeat the above-described process, and when the obtained blade width Sa becomes equal to or more than the threshold value SS, the obtained twist angle β and memory The shape of the processing tool 42 is determined based on the number of blades Z (step S5 in FIG. 2, tool determination step).

  The data of the determined shape of the processing tool 42 is displayed, for example, on the display unit of the control device 100 (not shown). Therefore, the worker manufactures the processing tool 42 based on the display data, attaches the manufactured processing tool 42 to the rotating spindle 40, and gives the intersection angle φ to the workpiece W. The processing control unit 102 manufactures a gear by processing the workpiece W by relatively feeding operation in the direction of the rotation axis Lw of the workpiece W while rotating the processing tool 42 in synchronization with the workpiece W (FIG. 2 Step S6, processing step).

(effect)
The gear machining device 1 according to the present embodiment uses the processing tool 42 having the rotational axis L inclined with respect to the rotational axis Lw of the workpiece W, and rotates the processing tool 42 in synchronization with the workpiece W. The gear is processed relatively by feeding operation in the direction of the rotation axis Lw. The cutting edge 42b of the tool blade 42a of the processing tool 42 is formed to twist with respect to the rotation axis L of the processing tool 42, and the twist angle β of the cutting edge 42b is set to the twist angle θ of the gear. It is formed at an angle obtained by adding the crossing angle φ between the rotation axis L of the tool 42 and the rotation axis Lw of the workpiece W.

  As a result, the twist angle β of the blade line 42b of the tool blade 42a increases, so the blade width Sa of the tool blade 42a also increases. Therefore, since it is easy to deform a blade edge at the time of processing, generation of chatter vibration can be suppressed and processing accuracy can be improved. In particular, when the tooth base width of the workpiece W is narrow, the cutting edge width Sa of the tool blade 42a becomes narrow in the conventional device, but in the device of this embodiment, the cutting edge width Sa of the tool blade 42a can be increased. .

  Further, the processing tool 42 sets the number of blades Z of the tool blade 42a, sets the crossing angle φ, obtains the twist angle β of the blade line, and based on the set number of blades Z and the calculated twist angle β It is formed by obtaining the cutting edge width Sa of the tool blade 42a. As a result, it is possible to obtain the processing tool 42 having the large tool edge 42a of the cutting edge width Sa.

  Further, in the gear machining method of the present embodiment, the rotation axis L is inclined with respect to the rotation axis Lw of the workpiece W, and the blade 42b of the tool blade 42a is formed to be twisted with respect to the rotation axis L. Gear machining method for machining a gear using a machining tool 42. Then, the blade number setting step (step S1 in FIG. 2) for setting the number of blades Z of the tool blade 42a, and the crossing angle φ between the rotation axis L of the processing tool 42 and the rotation axis Lw of the workpiece W The twist angle calculation step (step S2 in FIG. 2) for determining the twist angle β of the blade 42b, and the blade width calculation step (for finding the blade width Sa of the tool blade 42a based on the set number of blades Z and the twist angle β) And step S3) in FIG.

  Furthermore, the tool determination step of determining the shape of the processing tool based on the twist angle β of the cutting edge 42b and the set number of cutting edges Z when the calculated cutting edge width Sa becomes equal to or greater than the predetermined value SS (FIG. S4) and a processing step (step S6 in FIG. 2) of processing the gear by relatively feeding operation in the direction of the rotational axis Lw of the workpiece W while synchronously rotating the processing tool 42 determined with the workpiece W; Equipped with As a result, the twist angle β of the blade line 42b of the tool blade 42a increases, so the blade width Sa of the tool blade 42a also increases. Therefore, since it is easy to deform a blade edge at the time of processing, generation of chatter vibration can be suppressed and processing accuracy can be improved. In addition, since the rigidity of the cutting edge is high, the wear can be reduced and the life can be improved.

(Others)
In the embodiment described above, the gear machining device 1 which is a 5-axis machining center is configured to be capable of turning the workpiece W along the A axis. On the other hand, the 5-axis machining center may be configured to be capable of turning the processing tool 42 along the A axis as a vertical machining center. Moreover, although the case where this invention was applied to a machining center was demonstrated, it is applicable similarly to the exclusive machine of gear processing. Moreover, although the gear (helical gear) etc. which have a twist angle as a workpiece W, etc. are good, it can process also with another gear.

  1: Gear processing apparatus 42: Processing tool 42a: Tool blade 42a: Tool blade 42b: Blade streaks 100: Control device 101: Tool design unit 102: Machining control unit 103: Storage unit W : Workpiece, β: Twist angle of blade line

Claims (2)

Relative to the rotational axis of the workpiece, using a machining tool having an axis of rotation inclined by crossing angle, a gear machining apparatus for machining a gear before Symbol workpiece,
A control unit having a storage unit, a tool design unit, and a processing control unit;
The storage unit stores the crossing angle, the number of blades of the processing tool, and the twist angle of the gear.
The tool design unit calculates an angle obtained by adding the crossing angle to the twist angle of the gear as the twist angle of the blade edge of the tool blade of the processing tool, and based on the number of blades and the twist angle of the blade edge Determining the width of the cutting edge of the tool blade, and determining the shape of the processing tool based on the number of blades, the twist angle of the cutting edge, and the width of the cutting edge;
The processing control unit processes the gear by relatively performing a feed operation in the rotational axis direction of the workpiece while rotating the processing tool whose shape is determined by the tool design unit in synchronization with the workpiece. apparatus. A gear machining that has a rotation axis inclined by a crossing angle with respect to the rotation axis of the workpiece and a gear is machined using a processing tool that is formed by twisting a blade edge of the tool blade with respect to the inclined rotation axis Method,
A blade number setting step of setting the number of blades of the tool blade;
A twist angle calculation step of calculating an angle obtained by adding the crossing angle to the twist angle of the gear as the twist angle of the blade;
A cutting edge width calculating step of calculating a cutting edge width of the tool blade based on the set number of blades and the determined twist angle;
A tool determination step of determining the shape of the processing tool based on the twist angle of the blade and the set number of blades when the calculated blade width becomes equal to or greater than a predetermined value;
A processing step of processing the gear by relatively feeding operation in the rotation axis direction of the workpiece while rotating the determined processing tool in synchronization with the workpiece;
A gear machining method comprising:

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