JP6871675B2 - Gear processing equipment and gear processing method - Google Patents

Description

The present invention relates to a gear processing apparatus and a gear processing method for processing a gear by cutting by rotating a processing tool and a workpiece synchronously.

As an effective device for processing internal teeth and external teeth by cutting, for example, there is a processing device described in Patent Document 1. This processing device includes a workpiece that can rotate around the rotation axis and a machining tool that can rotate around the rotation axis that is inclined at a predetermined angle with respect to the rotation axis of the workpiece, that is, around the rotation axis that has an intersection angle. For example, it is a processing device that creates teeth by synchronously rotating a cutter having a plurality of tool blades at high speed and sending a processing tool in the direction of the rotation axis of the workpiece to perform cutting. Further, Patent Document 2 describes that in internal gear machining, the position and rotation of the machining tool are determined to set the crossing angle.

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

The tool blade of the above-mentioned machining tool is formed to have the same shape as the tooth that meshes with the gear to be machined on the tool end face. Then, when the cutting edge of the tool blade of the machining tool is worn, the worn cutting edge is polished and reused. However, if the amount of polishing exceeds a predetermined amount, there is a problem that the shape of the cutting edge of the tool blade of the machining tool is deformed and the machining accuracy is lowered.

The present invention has been made in view of such circumstances, and is a gear capable of maintaining machining accuracy for a long period of time when machining a gear by cutting using a machining tool having a tool blade formed on a tool end face. It is an object of the present invention to provide a processing apparatus and a gear processing method.

The gear processing apparatus of the present invention uses a machining tool having a rotation axis inclined with respect to the rotation axis of the workpiece, and while rotating the machining tool synchronously with the workpiece, it is relative to the rotation axis direction of the workpiece. It is a gear processing device that cuts gears by feed operation.
The end face of the tool blade of the machining tool in the tool axis direction is a rake face, and the outer peripheral surface of the tool blade is a front flank surface. By polishing only the end face of the tool blade, the tool The end face shape of the tool blade before polishing the end face of the blade and the end face shape of the tool blade after polishing are different shapes, and the twist angle of the tool blade before and after polishing the end face of the tool blade is It is the same.
The gear processing device is a tool state which is a relative position or posture of the processing tool with respect to the workpiece before polishing the tool blade of the processing tool, and after polishing the tool blade of the processing tool. The tool state storage unit that stores the tool state of the machining tool and the machining tool and the work piece are synchronously rotated in the same direction according to the ratio of the number of teeth to rotate the axis of rotation of the work piece and the work piece. Machining is performed by gradually shortening the distance between the axes of the rotation axis of the tool, and before polishing the tool blade of the machining tool, the tool state of the machining tool before polishing is stored in the tool state storage unit. Machining control in which the workpiece is machined and after the tool blade of the machining tool is polished, the workpiece is machined in the tool state of the machining tool after the polishing stored in the tool state storage unit. It has a part.
In the tool state storage unit, as the tool state, the intersection angle representing the inclination of the machining tool with respect to the rotation axis of the workpiece and the intersection of the tool end face of the machining tool and the tool axis are the workpieces. The amount of offset deviated from the rotation axis is stored. The crossing angle as the tool state before polishing and the crossing angle as the tool state after polishing are different angles, and the offset amount as the tool state before polishing and the polishing. It is different from the offset amount as the tool state later. The workpiece is machined before and after polishing the tool blade of the machining tool.

As a result, the optimum tool state of the machining tool before and after polishing can be obtained, and the machining accuracy can be maintained even if the number of polishings increases. Therefore, the life of the machining tool can be extended, and high-precision and low-cost gears can be obtained.

The gear machining method of the present invention uses a machining tool having a rotation axis inclined with respect to the rotation axis of the workpiece, and while rotating the machining tool synchronously with the workpiece, it is relative to the rotation axis direction of the workpiece. This is a gear processing method that cuts gears by feeding them to.
The end face of the tool blade of the machining tool in the tool axis direction is a rake face, and the outer peripheral surface of the tool blade is a front flank surface. By polishing only the end face of the tool blade, the tool The end face shape of the tool blade before polishing the end face of the blade and the end face shape of the tool blade after polishing are different shapes, and the twist angle of the tool blade before and after polishing the end face of the tool blade is It is the same.
In the gear machining method, the machining tool and the machining tool are rotated synchronously in the same direction according to the ratio of the number of teeth, and the distance between the rotation axis of the machining tool and the rotation axis of the machining tool is gradually increased. Before polishing the tool blade of the machining tool, the tool state is the relative position or orientation of the machining tool with respect to the workpiece before polishing, which is stored in the tool state storage unit. After polishing the tool blade of the machining tool, the workpiece is machined in the tool state of the machining tool after the polishing stored in the tool state storage unit.
The workpiece is cut before and after polishing the tool blade of the machining tool.
The tool state includes an intersection angle representing the inclination of the machining tool with respect to the rotation axis of the workpiece, and an offset in which the intersection of the tool end face and the tool axis of the machining tool deviates from the rotation axis of the workpiece. The amount. The crossing angle as the tool state before polishing and the crossing angle as the tool state after polishing are different angles, and the offset amount as the tool state before polishing and the polishing. It is different from the offset amount as the tool state later.

It is a perspective view which shows the whole structure of the gear processing apparatus which concerns on embodiment of this invention. It is a figure which shows the schematic structure and the control device of the gear processing apparatus of FIG. 1A. It is a flowchart for demonstrating the process of the control apparatus of FIG. 1B. It is the figure which looked at the schematic structure of the machining tool from the tool end face side in the direction of the rotation axis. FIG. 3 is a partial cross-sectional view of the schematic configuration of the machining tool of FIG. 3A as viewed in the radial direction. FIG. 3B is an enlarged view of a tool blade of the machining tool of FIG. 3B. 3C is a cross-sectional view taken along the line AA and a cross-sectional view taken along the line BB of the tool blade of FIG. 3C. It is a figure which shows the positional relationship between a machining tool and a work piece when the tool position in the direction of the rotation axis of a machining tool is changed. It is the first figure which shows the processing state when the position in the axial direction is changed. It is a second figure which shows the processing state when the position in the axial direction is changed. It is a third figure which shows the processing state when the position in the axial direction is changed. It is a figure which shows the positional relationship between a machining tool and a workpiece when changing the crossing angle which represents the inclination of the rotation axis of the machining tool with respect to the rotation axis of a workpiece. It is the first figure which shows the processing state when the intersection angle is changed. It is a second figure which shows the processing state when the intersection angle is changed. It is a third figure which shows the processing state when the intersection angle is changed. It is a figure which shows the positional relationship between a machining tool and a work piece at the time of changing the position in the direction of the rotation axis of the machining tool and the crossing angle. It is the first figure which shows the processing state when the position in the axial direction and the crossing angle are changed. It is a second figure which shows the processing state when the position in the axial direction and the crossing angle are changed. It is a figure which shows the machining state for each polishing of the conventional machining tool. It is a figure which shows the machining state for each polishing of the machining tool of this embodiment.

(Mechanical configuration of gear processing equipment)
In the present embodiment, a 5-axis machining center will be taken as an example of the gear processing apparatus 1, and will be described with reference to FIGS. 1A and 1B. That is, the gear processing device 1 is a device having three linear axes (X, Y, Z axes) and two rotation axes (A axis, C axis) orthogonal to each other as drive axes.

As shown in FIGS. 1A and 1B, the gear processing apparatus 1 includes a bed 10, a column 20, a saddle 30, a rotary spindle 40, a table 50, a tilt table 60, a turntable 70, and a workpiece holding. It is composed of a tool 80, a 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 arranged on the floor. However, the shape of the bed 10 is not limited to a rectangular shape. On the upper surface of the bed 10, a pair of X-axis guide rails 11a and 11b on which the column 20 can slide are formed so as to extend in the X-axis direction (horizontal direction) and parallel to each other. Further, on the bed 10, an X-axis ball screw (not shown) for driving the column 20 in the X-axis direction is arranged between the pair of X-axis guide rails 11a and 11b, and the X-axis ball screw is rotated. A driving X-axis motor 11c is arranged.

A pair of X-axis guide grooves 21a and 21b are formed on the bottom surface of the column 20 so as to extend in the X-axis direction and parallel to each other. A pair of X-axis guide grooves 21a and 21b are fitted onto the pair of X-axis guide rails 11a and 11b via ball guides 22a and 22b so that the column 20 can move in the X-axis direction with respect to the bed 10. , The bottom surface of the column 20 is brought into close contact with the top surface of the bed 10.

Further, on the side surface (sliding surface) 20a parallel to the X axis of the column 20, a pair of Y-axis guide rails 23a and 23b on which the saddle 30 can slide extend in the Y-axis direction (vertical direction), and , Formed parallel to each other. Further, in the column 20, a Y-axis ball screw (not shown) for driving the saddle 30 in the Y-axis direction is arranged between the pair of Y-axis guide rails 23a and 23b, and the Y-axis ball screw is rotated. A driving Y-axis motor 23c is arranged.

A pair of Y-axis guide grooves 31a and 31b are formed on the side surface 30a of the saddle 30 facing the sliding surface 20a of the column 20 so as to extend in the Y-axis direction and parallel to each other. A pair of Y-axis guide grooves 31a, 31b are fitted into the pair of Y-axis guide rails 23a, 23b so that the saddle 30 can move in the Y-axis direction with respect to the column 20, and the side surface 30a of the saddle 30 is the column 20. It is brought into close contact with the sliding surface 20a of the.

The rotary spindle 40 is rotatably provided by a spindle motor 41 housed in the saddle 30 and supports a machining tool 42. The machining tool 42 is held by the tool holder 43, fixed to the tip of the rotary spindle 40, and rotates as the rotary spindle 40 rotates. Further, the machining 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 machining tool 42 will be described later.

Further, on the upper surface of the bed 10, a pair of Z-axis guide rails 12a and 12b on which the table 50 can slide extend in the Z-axis direction (horizontal direction) orthogonal to the X-axis direction and are parallel to each other. It is formed. Further, on the bed 10, a Z-axis ball screw (not shown) for driving the table 50 in the Z-axis direction is arranged between the pair of Z-axis guide rails 12a and 12b, and the Z-axis ball screw is rotated. A driving Z-axis motor 12c is arranged.

The table 50 is provided on a pair of Z-axis guide rails 12a and 12b so as to be movable in the Z-axis direction with respect to the bed 10. A tilt table support portion 63 that supports the tilt table 60 is provided on the upper surface of the table 50. The tilt table support portion 63 is provided with a tilt table 60 that can rotate (swing) around the A axis in the horizontal direction. The tilt table 60 is rotated (swinged) by an A-axis motor 61 housed in the table 50.

The tilt table 60 is provided with a turntable 70 rotatably around the C axis perpendicular to the A axis. A work piece holder 80 for holding the work piece W is attached to the turntable 70. The turntable 70 is rotated by a C-axis motor 62 together with the workpiece W and the workpiece holder 80.

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

The tool state calculation unit 101, which will be described in detail later, is based on the polishing state of the tool blade 42a (see FIG. 3A, etc.) of the worn machining tool 42, and the relative position of the machining tool 42 with respect to the workpiece W or Calculate the tool state, which is the posture. That is, the tool state calculation unit 101 calculates the tool state before polishing the tool blade 42a and the tool state after polishing each time polishing is performed.
The tool state storage unit 103 stores the tool state calculated by the tool state calculation unit 101. That is, the tool state storage unit 103 stores the tool state of the machining tool 42 before polishing and the tool state of the machining tool 42 after polishing, which are calculated by the tool state calculation unit 101, respectively. ..

The machining control unit 102 controls the spindle motor 41 to rotate the machining 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 work piece W is cut by moving the work piece W and the work tool 42 relative to each other in the X-axis direction, the Z-axis direction, the Y-axis direction, the A-axis direction, and the C-axis direction. That is, when machining a helical gear on the outer peripheral surface of the cylindrical workpiece W, the machining control unit 102 is for machining while maintaining the tool state of the machining tool 42 stored in the tool state storage unit 103. The tool 42 and the workpiece W are synchronously rotated in the same direction according to the gear ratio. Then, while feeding the machining tool 42 in the rotation axis C (Lw shown in FIG. 4A or the like) direction of the workpiece W, the machining tool 42 is rotated according to the torsional angle of the helical gear as it is fed in the rotation axis C direction. The workpiece W is machined by gradually shortening the inter-axis distance between the rotary axis Lw of the object W and the rotary axis L of the tool end surface 42A of the machining tool 42 (see FIG. 4A and the like, hereinafter referred to as the tool axis L). Before polishing the tool blade 42a of the machining tool 42, the cutting of the workpiece W is performed in the tool state of the machining tool 42 with respect to the workpiece W before polishing stored in the tool state storage unit 103 for machining. After polishing the tool blade 42a of the tool 42, the tool state of the machining tool 42 after polishing stored in the tool state storage unit 103 is used. The same applies to the case where a helical gear is machined on the inner peripheral surface of the cylindrical workpiece W.

(Machining tool)
In the gear machining apparatus 1 described above, the machining tool 42 and the workpiece W are synchronously rotated at high speed, and the machining tool 42 is sent in the direction of the rotation axis of the workpiece W to perform cutting to create teeth. As shown in FIG. 3A, the shape of the tool blade 42a when the machining tool 42 is viewed from the tool end surface 42A side in the tool axis L direction is the shape of the teeth that mesh with the gear to be machined, and in this example, the shape of the involute curve. It is formed in the same shape. Then, as shown in FIG. 3B, the tool blade 42a of the machining tool 42 is provided with a rake angle inclined by an angle α with respect to a plane perpendicular to the tool axis L on the tool end surface 42A side, and is provided on the tool peripheral surface 42B side. A front clearance angle inclined by β with respect to a straight line parallel to the tool axis L is provided. Further, as shown in FIG. 3C, a side clearance angle inclined by an angle γ with respect to a straight line parallel to the tool axis L is provided on the side surface side of the tool blade 42a. That is, the tooth width of the tool blade 42a is smaller toward the proximal end side of the machining tool 42.

That is, as shown in FIG. 3D, the tool end face shape (the shape seen along the line AA in FIG. 3C) shown by the solid line shown when the tool blade 42a of the machining tool 42 is viewed from the tool end face 42A side in the tool axis L direction is , The cross-sectional shape of the tool blade 42a of the machining tool 42 shown by the illustrated one-point chain line in the direction perpendicular to the tool axis L direction at the position h from the tool end surface 42A in the tool axis L direction (line arrow BB in FIG. 3C). Compared with the visual shape), the involut curve shape and the tooth length H are formed to be constant, and the blade edge widths Wea and Web and the blade bottom widths Wba and Wbb are formed to change.

The design of such a machining tool 42 is performed by the following procedure. First, the crossing angle represented by the difference between the twist angle of the gear teeth to be machined and the twist angle of the tool blade 42a of the machining tool 42 to be machined, that is, the machining tool 42 with respect to the rotation axis Lw of the workpiece W. An intersection angle representing the inclination of the tool axis L (hereinafter, referred to as an intersection angle of the machining tool 42) is determined. Then, the number of blades of the tool blade 42a and the diameter of the machining tool 42 are determined. Finally, the front clearance angle β and the side clearance angle γ of the tool blade 42a are determined.

When the cutting edge of the tool blade 42a of such a machining tool 42 is worn, the worn cutting edge 42a is polished and reused. However, since the machining tool 42 has a front clearance β, the end face shape of the tool blade 42a of the machining tool 42 before polishing is different from the end face shape of the tool blade 42a of the machining tool 42 after polishing. Become. That is, as shown in FIG. 3D, the tool blade 42a of the machining tool 42 has a cutting edge width Web of the tool blade 42a of the machining tool 42 when the polishing amount of the tool blade 42a of the machining tool 42 reaches a predetermined amount h. Is larger than the blade edge width Wea before polishing, so that the machining accuracy of the workpiece W is lowered.

Therefore, the control device 100 processes the workpiece W in the tool state of the machining tool 42 according to the polishing state of the tool blade 42a of the machining tool 42. Specific methods for changing the tool state include changing the tool position in the direction of the rotation axis L of the machining tool 42 (hereinafter referred to as the axial position of the machining tool 42) and around the tool axis L of the machining tool 42. There is a change in the tool position in the direction (hereinafter, referred to as a position in the axial direction of the machining tool 42), a change in the intersection angle of the machining tool 42, or a combination thereof. As a result, the workpiece W is processed with high accuracy.

As a change in the axial position of the machining tool 42, for example, as shown in FIG. 4A, the intersection P of the tool end surface 42A of the machining tool 42 and the tool axis L is located on the rotation axis Lw of the workpiece W. (Offset amount 0), when the machining tool 42 is offset by a distance + d in the tool axis L direction (offset amount + d), and when the machining tool 42 is offset by a distance −d in the tool axis L direction (offset amount). The work piece W was processed in −d). As a result, the processing states of the workpiece W are shown in FIGS. 4B, 4C, and 4D. In the figure, the thick solid line E represents the involute curve of the design gear tooth g converted into a straight line, and the dot portion D represents the cutting-removed portion of the workpiece W.

As shown in FIG. 4B, when the offset amount is 0, the processed gear teeth are processed into a shape close to the design involute curve. On the other hand, as shown in FIG. 4C, at the offset amount + d, the processed gear teeth are deviated from the design involut curve in the right direction (dotted arrow direction), that is, in the clockwise pitch circle direction. As shown in FIG. 4D, at the offset amount −d, the gear teeth processed in the above-mentioned left direction (dotted arrow direction), that is, the counterclockwise pitch circular direction with respect to the design involut curve. It is processed in a shape that deviates from the shape. Therefore, the shape of the gear teeth can be shifted in the pitch circular direction by changing the position of the machining tool 42 in the tool axis L direction.

Further, as a change of the crossing angle of the machining tool 42, for example, as shown in FIG. 5A, the workpiece W was machined at angles θa, θb, and θc. The magnitude relationship of each angle is θa> θb> θc. As a result, the processing states of the workpiece W are shown in FIGS. 5B, 5C, and 5D.

As shown in FIG. 5B, at the intersection angle θa, the processed gear teeth are processed into a shape close to the design involute curve. On the other hand, as shown in FIG. 5C, at the intersection angle θb, the width of the tooth tip of the machined gear tooth is narrowed in the pitch circular direction (solid arrow direction) with respect to the design involut curve, and the width of the tooth root is wide. Is machined in a shape that expands in the pitch circular direction (solid arrow direction), and as shown in FIG. 5D, at the intersection angle θc, the gear teeth that have been machined have a width of the tip of the gear with respect to the design involut curve. It is processed into a shape that is further narrowed in the pitch circle direction (solid line arrow direction) and the width of the tooth base is further widened in the pitch circle direction (solid line arrow direction). Therefore, the shape of the tooth of the gear can change the width of the tooth tip in the pitch circular direction and the width of the tooth root in the pitch circular direction by changing the crossing angle of the machining tool 42.

Further, as a change of the axial position of the machining tool 42 and the intersection angle of the machining tool 42, for example, as shown in FIG. 6A, the intersection P of the tool end surface 42A of the machining tool 42 and the tool axis L is set. It is located on the rotation axis Lw of the work piece W (offset amount 0) and has an intersection angle θa, and is offset by a distance + d in the tool axis L direction of the machining tool 42 (offset amount + d) and has an intersection angle θb. In the case of, the work piece W was processed. As a result, the processed state of the workpiece W is shown in FIGS. 6B and 6C.

As shown in FIG. 6B, when the offset amount is 0 and the intersection angle θa is set, the processed gear teeth are processed into a shape close to the design involute curve. On the other hand, as shown in FIG. 6C, when the offset amount + d and the intersection angle θb, the processed gear teeth are in the right direction (dotted arrow direction) shown in the drawing, that is, in the clockwise pitch circle direction with respect to the design involute curve. It is processed in a shape in which the width of the tooth tip is narrowed in the pitch circle direction (solid line arrow direction) and the width of the tooth base is widened in the pitch circle direction (solid line arrow direction). Therefore, the shape of the tooth of the gear is shifted in the pitch circular direction by changing the axial position of the machining tool 42 and the intersection angle of the machining tool 42, and the width of the tooth tip in the circumferential direction and the pitch of the tooth root. The width in the circular direction can be changed.

(Processing by the tool state calculation unit of the control device)
Next, a simulation process of the control device 100 when the cross angle is obtained as the optimum tool state of the machining tool 42 when the tool blade 42a is polished will be described with reference to FIG. This simulation calculates the locus of the tool blade 42a based on a known gear creation theory. That is, in this simulation, a machining tool 42 having a tool axis L inclined with respect to the rotation axis Lw of the workpiece W is used, and the machining tool 42 is rotated synchronously with the workpiece W in the direction of the rotation axis Lw of the workpiece W. It corresponds to the operation of machining the teeth of the gear by the feed operation relative to.

The tool state calculation unit 101 of the control device 100 determines whether or not it has been polished (step S1 in FIG. 2). If it is not after polishing, the tool state calculation unit 101 reads out the shape of the machining tool 42 before polishing, which is designed and stored in advance (step S2 in FIG. 2). On the other hand, after polishing, the tool state calculation unit 101 calculates the shape of the machining tool 42 after polishing according to the set amount of polishing (step S3 in FIG. 2).

Then, the tool state calculation unit 101 reads out the tool state including the crossing angle of the machining tool 42 according to the polishing state (step S4 in FIG. 2). The tool state read out here is a tool state including the crossing angle stored in advance before polishing, and is set to a tool state including the crossing angle selected immediately before the polishing after polishing, for example. Then, the tool state calculation unit 101 remembers that it is the first time as the number of simulations n (step S5 in FIG. 2), and sets the read tool state of the machining tool 42 to the initial tool state of the machining tool 42. (Step S6 in FIG. 2).

Then, the tool state calculation unit 101 calculates the tool locus when machining the workpiece W based on the shape of the machining tool 42 before or after polishing (step S7 in FIG. 2), and the gear after machining. The shape of the tooth is calculated (step S8 in FIG. 2). Then, the tool state calculation unit 101 compares the calculated shape of the gear tooth after machining with the shape of the design gear tooth, calculates and stores the shape error (step S9 in FIG. 2), and stores the shape error. 1 is added to the number of simulations n (step S10 in FIG. 2).

Then, the tool state calculation unit 101 determines whether or not the number of simulations n has reached the preset number of times nn (step S11 in FIG. 2), and when the number of simulations n has not reached the set number of times nn, machining The intersection angle of the tool 42 is changed (step S12 in FIG. 2), the process returns to step S7, and the above process is repeated. On the other hand, when the number of simulations n reaches the set number of times nn, the tool state calculation unit 101 selects an intersection angle that is the smallest error among the stored shape errors (step S13 in FIG. 2). By the above processing, it is possible to determine the tool state including the optimum crossing angle of the respective optimum machining tools 42 before or after polishing the tool blade 42a. Then, the tool state calculation unit 101 stores the tool state of the machining tool 42 in the tool state storage unit 103.

In step S12, instead of changing the crossing angle of the machining tool 42, the axial position of the machining tool 42 is changed, or the axial position of the machining tool 42 is changed, or the crossing angle is changed. , Arbitrary combination of axial position and axial position may be changed. Further, in the above processing, the crossing angle that is the minimum error is selected by performing a plurality of simulations, but the allowable shape error is set in advance, and the shape error calculated in step S9 is the allowable shape error. You may select the intersection angle when the following.

(Effect of simulation processing)
The above-mentioned simulation process is performed every time the tool blade 42a is polished. As a result, the optimum tool state of the machining tool 42 for each polishing can be obtained, and the machining accuracy can be maintained even if the number of polishings increases. For example, in FIGS. 7A and 7B, similarly to FIG. 5, the thick solid line E in the figure represents the involute curve of the design gear tooth g converted into a straight line, and the dot portion D is processed. Represents the cutting-removed portion of the object W. As shown in FIG. 7A, conventionally, up to 4 times of polishing, the shape of the gear tooth g after processing is processed because the shape error is within the allowable range with respect to the design gear tooth shape. The tool 42 can be used. When the number of polishings is 5 or more, the shape error of the tooth shape of the gear g after machining exceeds the permissible range with respect to the design gear tooth shape, so that the machining tool 42 cannot be used. Become. However, as shown in FIG. 7B, in the present embodiment, even if the number of times of polishing is 6, the shape of the tooth shape of the gear g after processing has a shape error within an allowable range with respect to the shape of the gear tooth in design. Since it is inside, the machining tool 42 can be used, and the life of the machining tool 42 can be extended. Therefore, a gear with high accuracy and low cost can be obtained.

Further, the tool state calculation unit 101 sets the tool state as at least one of the position in the rotation axis L direction of the machining tool 42, the position in the rotation axis L rotation direction of the machining tool 42, and the intersection angle of the machining tool 42, or Since these combinations are calculated, a highly accurate gear can be obtained. Further, since the tool state calculation unit 101 calculates the tool state by simulation, actual machining is not required, and a low-cost gear can be obtained.

(Other)
In the above-described embodiment, as the machining tool 42, a tool having no twist angle has been described as an example, but a tool having a twist angle can be similarly applied. Further, the gear processing device 1 which is a 5-axis machining center enables the workpiece W to be swiveled around the A axis. On the other hand, the 5-axis machining center may be configured as a vertical machining center so that the machining tool 42 can turn around the A-axis. Further, although the case where the present invention is applied to a machining center has been described, it can be similarly applied to a dedicated machine for gear machining.

1: Gear processing device, 42: Tool for processing, 42a: Tool blade, 100: Control device, 101: Tool state calculation unit, 102: Processing control unit, 103: Tool state storage unit, W: Work piece

Claims (5)

Using a machining tool having a rotation axis that is inclined with respect to the rotation axis of the workpiece, the gear is cut by feeding the machining tool relative to the rotation axis direction of the workpiece while rotating the machining tool in synchronization with the workpiece. It is a gear processing device to process
The end surface of the tool blade of the machining tool in the tool axis direction is a rake surface, and the outer peripheral surface of the tool blade is a front flank surface.
By polishing only the end face of the tool blade, the shape of the end face of the tool blade before polishing the end face of the tool blade and the shape of the end face of the tool blade after polishing are different, and the shape is the same . The twist angle of the tool blade before and after polishing the end face of the tool blade is the same.
The gear processing device is
The tool state, which is the relative position or orientation of the machining tool with respect to the workpiece before polishing the tool blade of the machining tool, and the tool of the machining tool after polishing the tool blade of the machining tool. Tool state storage unit that stores the state, and
By synchronously rotating in the same direction according to the ratio of the number of teeth of the machining tool and the workpiece, the distance between the axis of rotation of the workpiece and the axis of rotation of the machining tool is gradually reduced for machining. Before polishing the tool blade of the machining tool, the workpiece is machined in the tool state of the machining tool before polishing stored in the tool state storage unit, and the tool blade of the machining tool After polishing, a machining control unit that processes the workpiece in the tool state of the machining tool after polishing, which is stored in the tool state storage unit,
With
In the tool state storage unit, as the tool state, the intersection angle representing the inclination of the machining tool with respect to the rotation axis of the workpiece and the intersection of the tool end face of the machining tool and the tool axis are the workpieces. Memorize the amount of offset that deviates from the rotation axis,
The crossing angle as the tool state before polishing and the crossing angle as the tool state after polishing are different angles, and the offset amount as the tool state before polishing and the polishing. Unlike the offset amount as the tool state later,
A gear processing device that processes the workpiece before and after polishing the tool blade of the processing tool. The gear processing device according to claim 1, wherein the tool state storage unit stores the tool state obtained based on a result of calculating the tool state by simulation. The front flank surface of the tool blade has a front flank angle inclined by a predetermined angle with respect to a straight line parallel to the tool axis.
The gear processing apparatus according to claim 1 or 2, wherein the tool blade has the front clearance angle, so that the end face shape of the tool blade before and after polishing is different. The gear processing apparatus according to claim 3, wherein the tool blade of the processing tool has an involute tooth profile. Using a machining tool having a rotation axis that is inclined with respect to the rotation axis of the workpiece, the gear is cut by feeding the machining tool relative to the rotation axis direction of the workpiece while rotating the machining tool in synchronization with the workpiece. It is a gear processing method to process
The end surface of the tool blade of the machining tool in the tool axis direction is a rake surface, and the outer peripheral surface of the tool blade is a front flank surface.
By polishing only the end face of the tool blade, the shape of the end face of the tool blade before polishing the end face of the tool blade and the shape of the end face of the tool blade after polishing are different, and the shape is the same . The twist angle of the tool blade before and after polishing the end face of the tool blade is the same.
The gear processing method is
By synchronously rotating in the same direction according to the gear ratio between the machining tool and the workpiece, the distance between the rotation axis of the workpiece and the rotation axis of the machining tool is gradually reduced for machining. ,
Before polishing the tool blade of the machining tool, the machining of the workpiece is performed in the tool state which is the relative position or orientation of the machining tool with respect to the workpiece before polishing stored in the tool state storage unit. Do,
After polishing the tool blade of the machining tool, the workpiece is machined in the tool state of the machining tool after the polishing stored in the tool state storage unit.
There line cutting of the workpiece after grinding and before polishing the tool blades of the machining tool,
The tool state includes an intersection angle representing the inclination of the machining tool with respect to the rotation axis of the workpiece, and an offset in which the intersection of the tool end face and the tool axis of the machining tool deviates from the rotation axis of the workpiece. Is the quantity
The crossing angle as the tool state before polishing and the crossing angle as the tool state after polishing are different angles, and the offset amount as the tool state before polishing and the polishing. A gear machining method different from the offset amount as the tool state later.

Images