JP7456191B2 - Gear processing equipment and gear processing method - Google Patents

Description

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

BACKGROUND ART Conventionally, for example, a gear processing device disclosed in Patent Document 1 below has been known. This conventional gear processing apparatus includes a workpiece holding device that is movable with respect to the bed, and a tool holding device that is movable with respect to the bed and the workpiece holding device. In a conventional gear processing device, a workpiece detection sensor that detects the shape of a workpiece held by the workpiece holding device is movably provided with the tool holding device. Furthermore, in conventional gear processing equipment, a tool detection sensor is movably provided integrally with the workpiece holding device to detect the shape of a cutting edge formed on a processing tool held by the tool holding device. .

In conventional gear processing equipment, when a tool and a workpiece are installed or replaced, a tool detection sensor is placed at a detectable position to detect the shape of the tool, and a workpiece detection sensor is also placed at a detectable position. Detect the shape of the workpiece by placing it at the desired position. Conventional gear machining equipment uses the detection result of the shape of the tool detected by the tool detection sensor and the detection result of the shape of the workpiece detected by the workpiece detection sensor to identify the tool and workpiece. It is designed to perform phase matching to match the phases of the two.

JP2019-115948A

In the conventional gear processing apparatus described above, the tool detection sensor and the workpiece detection sensor are arranged at respective detectable positions. As a result, in the above-mentioned conventional gear processing device, when a tool is installed or replaced, or when a workpiece is installed or replaced, based on the detection results of the tool detection sensor and the workpiece detection sensor, , the tool and workpiece can be aligned in phase. Furthermore, in the conventional gear processing apparatus described above, thermal displacement may occur between the tool holding device and the workpiece holding device due to processing heat generated by processing the workpiece. Even in this case, by sequentially placing sensors in detectable positions, the shape can be detected while eliminating the influence of thermal displacement. You can match the phase with objects.

By the way, in order to always accurately detect the tool phase of the tool and the tooth phase of the workpiece, it is preferable to match the relative positions of the tool detection sensor and the tool and the workpiece detection sensor and the workpiece. Therefore, in the conventional gear processing apparatus described above, it is necessary to index the center position of the tool when the tool detection sensor detects the shape (phase) of the cutting edge. Furthermore, in the conventional gear processing equipment described above, in addition to determining the center position of the tool, it is also necessary to determine the center position of the workpiece when the workpiece detection sensor detects the shape (phase) of the workpiece. be.

Furthermore, even if the center position of the tool and the workpiece are determined in advance, for example, if thermal displacement occurs between the tool holding device and the workpiece holding device, the center position of the tool and the workpiece may be affected by the thermal displacement. This causes a deviation in the predetermined center position of the tool and the center position of the workpiece. Therefore, even if the center position of the tool and the center position of the workpiece are determined in advance, it is necessary to index the center position of the tool and the center position of the workpiece anew. As described above, determining the respective center positions of the tool and the workpiece is complicated and time consuming, and therefore improvements are desired.

The present invention aims to provide a gear machining device and a gear machining method that can simplify the manufacturing process of workpieces and shorten the cycle time.

(Gear processing equipment)
The gear machining device is a gear machining device which relatively feeds a machining tool and a workpiece while rotating them synchronously, and cuts the peripheral surface of the workpiece to create teeth, and includes a tool holding device which rotatably holds the machining tool, a workpiece holding device which rotatably holds the workpiece, a workpiece detection sensor provided on the tool holding device which detects the rotational position of the teeth of the workpiece held by the workholding device, a tool detection sensor provided on the workholding device which detects the rotational position of a tool blade formed on the machining tool held by the tool holding device, a position control unit which controls the positions of the tool holding device and the workholding device so that they are movable relative to each other, and a tool phase of the machining tool, a workpiece detection sensor provided on the workholding device which detects the rotational position of a tool blade formed on the machining tool held by the tool holding device, a position control unit which controls the positions of the tool holding device and the workholding device so that they are movable relative to each other, and a tool detection sensor provided on the workholding device which detects the rotational position of a tool blade formed on the machining tool held by the tool holding device. and a control device including a phase detection unit which detects both a tooth phase of a crop, or a tool phase of a machining tool and a tooth phase of a workpiece, wherein the phase detection unit determines a center position of the rotating spindle body based on a detection result detected by the tool detection sensor by relatively moving the tool holding device in a direction in which the rotating spindle body including the machining tool crosses with respect to a detection direction of the tool detection sensor by the position control unit, and determines a first detection position for arranging the tool detection sensor using the center position, and detects the tool phase of the machining tool based on a detection result of the tool detection sensor arranged at the first detection position by position control by the position control unit, or the phase detection unit determines a position control the control unit relatively moves the tool holding device in a direction in which a rotating spindle including a machining tool crosses with respect to the detection direction of the tool detection sensor, thereby indexing a center position of the rotating spindle based on a detection result detected by the tool detection sensor, and determining a second detection position at which the workpiece detection sensor is to be disposed using the center position and a positional relationship between the rotating spindle and the workpiece detection sensor, and detecting a tooth phase of the workpiece based on a detection result of the workpiece detection sensor disposed at the second detection position by position control by the position control unit; or the phase detection unit relatively moves the tool holding device in a direction in which a rotating spindle including a machining tool crosses with respect to the detection direction of the tool detection sensor, thereby indexing a center position of the rotating spindle based on a detection result detected by the tool detection sensor, and determining a first detection position at which the tool detection sensor is to be disposed using the center position, and detecting a tool phase of the machining tool based on a detection result of the tool detection sensor disposed at the first detection position by position control by the position control unit; and further determining a second detection position at which the workpiece detection sensor is to be disposed using the center position and a positional relationship between the rotating spindle and the workpiece detection sensor, and detecting a tooth phase of the workpiece based on a detection result of the workpiece detection sensor disposed at the second detection position by position control by the position control unit .

(Gear processing method)
The gear machining method is a gear machining method in which the peripheral surface of the workpiece is cut by rotating the machining tool synchronously with the workpiece and feeding it relative to the workpiece, thereby creating teeth on the peripheral surface. A tool holding device that rotatably holds a tool, a workpiece holding device that rotatably holds a workpiece, and a device installed in the tool holding device to detect the rotational position of the teeth of the workpiece held by the workpiece holding device. a workpiece detection sensor installed in a workpiece holding device to detect the rotational position of a tool blade formed on a processing tool held by the tool holding device; a tool holding device and a workpiece holding device; a position control unit that controls the relative position of the processing tool, and a phase detection unit that detects the tool phase of the processing tool and the tooth phase of the workpiece based on the detection result of the tool detection sensor and the detection result of the workpiece detection sensor. A first step in which the position control unit moves the tool holding device in a direction transverse to a rotating main shaft body including a processing tool with respect to a detection direction of the tool detection sensor. , a second step in which the phase detection unit determines the center position of the rotational spindle based on the distance to the outer peripheral surface of the rotational spindle detected by the tool detection sensor as the rotational spindle moves, and the phase detection unit The center position is used to determine the first detection position where the tool detection sensor is placed, and the processing tool is determined based on the detection result of the tool detection sensor placed at the first detection position by the position control by the position control unit. a third step of detecting the tool phase; the phase detection section determines a second detection position at which the workpiece detection sensor is placed using the center position and the positional relationship between the rotating spindle body and the workpiece detection sensor; The method includes a fourth step of detecting the tooth phase of the workpiece based on the detection result of the workpiece detection sensor placed at the second detection position under position control by the control unit.

According to these, the phase detection section can determine the center position of the rotating main shaft body based on the detection result detected by the tool detection sensor. Then, the phase detection section determines the first detection position of the tool detection sensor using the indexed center position, and can detect the phase of the processing tool. Further, the phase detection section determines a second detection position of the workpiece detection sensor using the indexed center position and the positional relationship between the rotating main shaft body and the workpiece detection sensor, and detects the phase of the workpiece. I can do it.

That is, according to the gear processing apparatus and the gear processing method, it is not necessary to separately detect the center position of the workpiece by simply determining the center position of the rotating main shaft body. This makes it possible to omit the step of detecting the center position of the workpiece, for example, when installing or replacing a tool or workpiece, or even when thermal displacement occurs. Therefore, the complicated work of determining the center position of each tool and workpiece is not required, and the time required to determine the center position of the workpiece is not required, so the cycle time required for machining can be shortened. It becomes possible.

1 is a diagram showing the overall configuration of a gear processing device. FIG. 2 is a partial cross-sectional view showing the configuration of a processing tool (skiving cutter). FIG. 2 is a block diagram of a control device. It is a flowchart of gear processing processing performed by a control device. It is a flowchart of the phase matching process performed in gear machining process. FIG. 3 is a diagram for explaining detected positional deviation. It is a graph showing a rough relationship between a detected positional deviation amount and a detection groove detection error. FIG. 6 is a diagram for explaining a state in which the tool detection sensor detects the center position of the tool holder and the detection groove of the tool holder. It is a figure for explaining operation when a tool detection sensor detects the center position of a tool holder. It is a graph which shows the rough relationship between the position of a tool holder and detection distance in the direction (parallel to the X-axis line) which a rotating main shaft crosses. 9 is a cross-sectional view taken along the line XI-XI in FIG. 8, showing a state in which the tool holder holds a machining tool and the tool detection sensor is placed at a first detection position with respect to the tool holder. FIG. FIG. 9 is a cross-sectional view taken along the line XI-XI in FIG. 8, showing a state in which the rotating main shaft and the workpiece detection sensor are moved integrally. 9 is a cross-sectional view taken along the line XI-XI in FIG. 8, showing a state in which the workpiece is held by the workpiece holding device and the workpiece detection sensor is disposed at a second detection position with respect to the workpiece. FIG. It is a figure which shows an example of the output information (voltage change) output to a phase detection part from a workpiece detection sensor.

(1. Applicable gear processing equipment)
A gear processing device changes the rotational speed of the processing tool and the workpiece, and rotates the processing tool and the workpiece synchronously, while moving the blade cutting tool against the workpiece along the rotational axis direction of the workpiece. By relatively moving the gear (feeding operation), the gear is cut into the workpiece. In this example, a gear processing device is equipped with a skiving cutter as a processing 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 machining center having a In this example, the direction parallel to the X-axis and the Z-axis is the horizontal direction, and the direction parallel to the Y-axis is the vertical direction.

(2. Configuration of gear processing device 1)
As shown in FIG. 1, the gear processing apparatus 1 includes a bed 10, a column 20, a saddle 30, a rotating main shaft 40, a table 50, a tilt table 60, a turntable 70, a holder 80, and a tool. It mainly includes an exchange device 90 and a control device 100. Here, in this example, the column 20, saddle 30, and rotating main shaft 40 constitute a "tool holding device." Further, in this example, the table 50, tilt table 60, turntable 70, and holder 80 constitute a "workpiece holding device."

The bed 10 has a substantially rectangular shape and is arranged horizontally. An X-axis ball screw (not shown) is arranged on the top surface of the bed 10 to drive the column 20 in a direction parallel to the X-axis, that is, in a horizontal direction. An X-axis motor 11 that rotationally drives an X-axis ball screw is arranged on the bed 10. Here, in this example, the direction parallel to the X-axis, ie, the horizontal direction, is the "direction across which the rotating main shaft body crosses."

A Y-axis ball screw (not shown) is disposed on a side surface (sliding surface) 20a of the column 20 parallel to the Y-axis for driving the saddle 30 in a direction parallel to the Y-axis, that is, in a vertical direction. A Y-axis motor 21 that rotationally drives a Y-axis ball screw is arranged in the column 20.

The saddle 30 integrally supports a workpiece detection sensor 31 that detects the shape of a workpiece W held on a turntable 70, specifically, the phase of generated teeth, as will be described later, and also supports a rotational main shaft 40. rotatably supported. As a result, when the saddle 30 moves, the workpiece detection sensor 31 and the rotation main shaft 40 can be operated without the workpiece detection sensor 31 moving relative to the rotation main shaft 40, that is, the rotation main shaft 40 and the saddle 30 moves together with the saddle 30.

Here, the saddle 30 supports the workpiece detection sensor 31 and the rotating main shaft 40. Therefore, when the saddle 30 is thermally displaced with respect to the turntable 70, the workpiece detection sensor 31 and the rotation main shaft 40 are thermally displaced with respect to the turntable 70 together with the saddle 30. That is, the workpiece detection sensor 31 in the saddle 30 and the rotating main shaft 40 are immovable relative to each other, and the positional relationship between the workpiece detecting sensor 31 in the saddle 30 and the rotating main shaft 40 is maintained.

The workpiece detection sensor 31 is a non-contact type sensor in this example. Examples of the workpiece detection sensor 31 include an eddy current sensor, an electromagnetic pickup, and a laser sensor. The workpiece detection sensor 31 of this example uses an eddy current sensor, and detects the shape of a gear formed on the workpiece W, specifically, the distance to the tooth top surface and tooth bottom surface. Note that the workpiece detection sensor 31 may be a contact type sensor, such as a touch probe sensor.

The workpiece detection sensor 31 is supported by the saddle 30 so that the detection direction is parallel to the Y-axis, that is, in the vertical direction. The workpiece detection sensor 31 detects the rotational position (tooth phase) of the teeth created on the workpiece W. Further, the workpiece detection sensor 31 of this example is supported on the side surface 30a of the saddle 30 facing the workpiece W via an expansion and contraction mechanism that allows expansion and contraction in a direction parallel to the Z-axis. As a result, the workpiece detection sensor 31 moves in a direction parallel to the X-axis and in a direction parallel to the Y-axis together with the rotation main shaft 40 as the saddle 30 moves, and also moves along the rotation axis J of the rotation main shaft 40 by the expansion and contraction mechanism. It can be displaced from the saddle 30 side toward the workpiece W side in a direction parallel to , that is, a direction parallel to the Z axis.

Note that the workpiece detection sensor 31 may be configured to omit the expansion/contraction mechanism, that is, to be configured such that it cannot expand or contract in the direction parallel to the axis of the rotational main shaft 40 (rotation main shaft body). In this case, the workpiece detection sensor 31 moves together with the saddle 30 in a direction parallel to the X-axis and a direction parallel to the Y-axis.

The rotation main shaft 40 is arranged parallel to the Z-axis which is perpendicular to the X-axis. The rotating main shaft 40 is rotatably supported by the saddle 30 and rotated by a main shaft motor 41 housed within the column 20 (or the saddle 30). The rotating main shaft 40 supports a machining tool 42 . The processing tool 42 is held by a tool holder 43 and attached to the tip of the rotating main shaft 40, and rotates as the rotating main shaft 40 rotates. Here, a "rotating main shaft body" is configured by assembling the tool holder 43 to the rotating main shaft 40 and attaching a processing tool to the tool holder 43.

The processing tool 42 and the tool holder 43 are moved in a direction parallel to the X-axis with respect to the bed 10, that is, in a horizontal direction, as the column 20 and saddle 30 are moved by the drive of the X-axis motor 11. It moves in the "direction across the rotating main shaft body" with respect to the detection direction of the detection sensor 64. Further, the processing tool 42 and the tool holder 43 move in a direction parallel to the Y-axis line as the column 20 and saddle 30 move due to the drive of the Y-axis motor 21.

The processing tool 42 of this example is a skiving cutter, and is designed based on the shape of the tooth surface formed on the workpiece W (specifically, a gear). As shown in FIG. 2, the machining tool 42 includes a plurality of tool blades 42a on the circumferential surface of the tool. In this example, the tool blade 42a is formed to have the same shape as the involute curve shape.

Here, the tool blade 42a is provided with a rake angle that is inclined by an angle γ with respect to a plane perpendicular to the rotation axis J of the cutting edge 42b. Further, the tool blade 42a is provided with a front clearance angle that is inclined by an angle δ with respect to a straight line parallel to the rotation axis J on the tool peripheral surface side. Further, the blade groove 42c of the tool blade 42a has a helix angle that is inclined by an angle β with respect to a straight line parallel to the rotation axis J. Note that the processing tool 42 may include a straight tool blade 42a that does not have the helix angle β and is parallel to the rotation axis J.

As shown in FIG. 2, the tool holder 43 is formed into a cylindrical shape, and forms a "rotating main shaft body" by being fixed to the rotating main shaft 40 at one end in a relatively non-rotatable manner, and at the other end. The machining tool 42 mounted or replaced by the tool exchanger 90 is supported so as not to be relatively rotatable. A concave detection groove 43a is provided on the outer peripheral surface of the tool holder 43 for detecting the phase (rotational position) of the processing tool 42 being mounted or replaced. Note that the number of detection grooves 43a may be at least one or more.

Further, as shown in FIG. 1, a Z-axis ball screw (not shown) is disposed on the top surface of the bed 10 to drive the table 50 in a direction parallel to the Z-axis. A Z-axis motor 12 that rotationally drives a Z-axis ball screw is arranged on the bed 10.

A tilt table support section 63 that supports the tilt table 60 is provided on the top surface of the table 50. The tilt table 60 is provided in the tilt table support section 63 so as to be rotatable (swingable) around the A axis. The tilt table 60 is rotated (swung) by an A-axis motor 61 housed within the table 50. A turntable 70 is provided on the tilt table 60 so as to be rotatable around the C-axis. Incidentally, the tilt table 60 may use a rotating table axis that is perpendicular to the C axis.

A holder 80 is attached to the turntable 70 to hold the workpiece W in a relatively non-rotatable manner. In this example, the turntable 70 and the holder 80 constitute a "workpiece spindle." The turntable 70 is rotated by the C-axis motor 62 together with the workpiece W and the holder 80. Here, the C-axis motor 62 is provided with an encoder 62a that detects the rotation angle around the C-axis.

A side surface 63a of the tilt table support portion 63 that is parallel to the Y-axis and that faces the rotational main shaft 40 (processing tool 42 and tool holder 43) integrally supports a tool detection sensor 64 as a tool detection sensor. That is, the tilt table support section 63 supports the tool detection sensor 64 in a non-displaceable manner, and also supports the turntable 70, which rotatably supports the workpiece W, via the tilt table 60. Thereby, the workpiece W and the tool detection sensor 64 are supported in the tilt table support section 63 so that they cannot move relative to each other.

When thermal displacement occurs in the tilt table support portion 63 relative to the saddle 30, the tool detection sensor 64 and the turntable 70 (workpiece W) are thermally displaced together with the tilt table support portion 63 relative to the saddle 30. That is, the positional relationship between the tool detection sensor 64 in the tilt table support portion 63 and the turntable 70, in other words, the workpiece W held by the holder 80 on the turntable 70, is maintained.

The tool detection sensor 64 is a non-contact type sensor in this example. Examples of the tool detection sensor 64 include an eddy current sensor, an electromagnetic pickup, and a laser sensor. The tool detection sensor 64 of this example uses an eddy current sensor, and uses a distance measurement sensor that detects the distance to the outer peripheral surface of the tool holder 43 (including the bottom surface of the detection groove 43a). Note that the tool detection sensor 64 may be a contact type sensor, such as a touch probe sensor.

In this example, the tool detection sensor 64 is supported by the tilt table support portion 63 so that its detection direction is parallel to the Y-axis, which is the same direction as the workpiece detection sensor 31, that is, in the vertical direction. As will be described later, the tool detection sensor 64 moves up to the outer peripheral surface of the tool holder 43 while the cylindrical tool holder 43 attached to the rotating main shaft 40 is moved in a direction parallel to the X-axis, that is, in a horizontal direction. Detect the distance. Further, the tool detection sensor 64 detects the distance to the outer peripheral surface of the tool holder 43 while the tool holder 43 is being rotated. As a result, the control device 100 detects the center position of the tool holder 43 and detects the detection groove 43a (see FIG. 2) provided in advance on the tool holder 43, thereby controlling the processing tool 42. Detect the phase of

Here, when the tool detection sensor 64 detects the phase (rotational position) of the tool blade 42a of the processing tool 42, the control device 100 moves the rotating main shaft 40 along with the column 20, that is, the saddle 30, in a direction parallel to the X-axis ( horizontally). At this time, the tool detection sensor 64 detects the distance to the outer peripheral surface of the tool holder 43, which moves together with the rotating main shaft 40 in a direction parallel to the X-axis.

As a result, the control device 100 determines the position parallel to the X-axis where the detection distance is shortest, that is, the apex position in the circumferential direction of the cylindrical tool holder 43, as the detection result detected by the tool detection sensor 64. Here, the apex position coincides with the center position of the tool holder 43 as a position parallel to the X-axis. The control device 100 then determines the determined center position (apex position) as the first detection position, and detects the detection groove 43a of the tool holder 43.

The tool exchange device 90 automatically exchanges the machining tool 42 mounted on the rotating main shaft 40 via the tool holder 43 with another machining tool 42 housed in a tool magazine (not shown). Note that the configuration and operation of the tool changer 90 are well known and can be referred to, for example, Japanese Patent Application Laid-Open No. 2018-103330, so a description thereof will be omitted.

The control device 100 is a computer device whose main components include a CPU, ROM, RAM, and various interfaces, and executes various programs. As shown in FIG. 3, the control device 100 includes a tool rotation control section 101, a workpiece rotation control section 102, a tilt control section 103, a position control section 104, a phase detection section 105, and a storage device 106. Prepare for the Lord.

The tool rotation control unit 101 controls the drive of the spindle motor 41 using the rotation angle detected by the encoder 41a, and rotates the tool holder 43 and the machining tool 42 together with the rotating spindle 40. The workpiece rotation control unit 102 controls the drive of the C-axis motor 62 using the rotation angle detected by the encoder 62a, and rotates the workpiece W held (fixed) in the cage 80 together with the turntable 70 around the C-axis. Rotate it. The tilt control unit 103 controls the drive of the A-axis motor 61 and swings the tilt table 60, thereby swinging the turntable 70 and the workpiece W around the A-axis.

The position control section 104 controls the positions of the column 20, that is, the saddle 30 that supports the workpiece detection sensor 31 and the rotating main shaft 40, and the table 50, that is, the tilt table support section 63 fixed to the table 50, so that they can move relative to each other. The position control unit 104 controls the drive of the X-axis motor 11, and moves the column 20 and the saddle 30 supported by the column 20 together in a direction parallel to the X-axis. Further, the position control unit 104 controls the drive of the Y-axis motor 21 to move the saddle 30 in a direction parallel to the Y-axis.

Thereby, the position control unit 104 moves the rotating main shaft 40 supported by the saddle 30 and the workpiece detection sensor 31 integrally in a direction parallel to the X-axis and a direction parallel to the Y-axis without relative displacement. In this example, the position control unit 104 controls the operation of the expansion and contraction mechanism of the workpiece detection sensor 31 supported by the saddle 30 so that the workpiece detection sensor 31 expands and contracts in a direction parallel to the Z-axis. do.

Further, the position control section 104 controls the drive of the Z-axis motor 12, and moves the table 50 and the tilt table support section 63 supported by the table 50 together in a direction parallel to the Z-axis line. Thereby, the position control section 104 moves the workpiece W supported by the tilt table support section 63 and the tool detection sensor 64 together in a direction parallel to the Z-axis without relative displacement.

The phase detection unit 105 determines the center position (apex position) of the tool holder 43 based on the distance to the tool holder 43 as a detection result detected by the tool detection sensor 64. Then, the phase detection unit 105 determines the center position, which is the detection result by the tool detection sensor 64, as the first detection position, and moves the tool holder 43 based on the change in distance detected by the tool detection sensor 64 at the first detection position. The detection groove 43a, that is, the phase (rotational position) of the processing tool 42 is detected. In this example, the phase detection unit 105 determines, as the phase (rotational position) of the machining tool 42, the tool phase of the cutting edge 42b, which is the highest in the direction parallel to the Y-axis, among the tool blades 42a of the machining tool 42. Detect.

Further, the phase detection unit 105 uses the center position of the tool holder 43, which is the detection result by the tool detection sensor 64, and the positional relationship between the rotating main shaft 40 and the workpiece detection sensor 31 in the saddle 30, to detect the workpiece detection sensor 31. A second detection position for detecting the tooth phase of the tooth bottom surface of the workpiece W is determined. Then, the phase detection unit 105 matches the phases of the machining tool 42 and the workpiece W based on the tool phase of the machining tool 42 and the tooth phase of the workpiece W.

The storage device 106 stores the detection results of the tool detection sensor 64 and the detection results of the workpiece detection sensor 31. Specifically, the storage device 106 stores information regarding the center position determined by the phase detection unit 105, information regarding the detected phase of the cutting edge 42b of the processing tool 42, and information about the gear formed on the workpiece W. Information regarding the phase of the root surface is stored. Further, the storage device 106 stores basic information about gears formed on the workpiece W (information about various dimensions, number of teeth, etc.) and basic information about the processing tool 42.

(3. Gear processing (gear processing method))
Next, gear machining processing executed by the control device 100 will be described using the flowchart shown in FIG. The gear machining process is performed when forming a gear on the workpiece W, which is a cylindrical blank, by gear machining.

In the gear machining process, in step S1, gear machining is performed on the cylindrical workpiece W held by the cage 80 as a rough machining process to form a gear on the workpiece W. In the subsequent step S2, the gear machining process involves hardening the workpiece W on which the gear has been formed by the rough machining process, as a hardening process.

In step S3, the gear machining process includes a phase alignment process when the hardened workpiece W is held in the cage 80 again or when the machining tool 42 is installed or replaced by the tool changer 90. conduct. As will be described in detail later, the phase alignment process in this example involves detecting the tool phase (rotational position) of the machining tool 42 mounted on the tool holder 43, and forming a Detects the tooth phase (rotational position) of the rotated tooth. In the phase matching process, phase matching is performed to match the detected tool phase (rotational position) of the machining tool 42 and the tooth phase (rotational position) of the teeth of the workpiece W.

When phase matching is performed in the phase matching process, the gear processing process performs finishing processing in step S4. In the finishing process, a gear on the workpiece W is finished. Here, when the workpiece W that has undergone gear processing is hardened, strain is generated in the workpiece W. Therefore, it is common practice to perform gear machining on the workpiece W after hardening again to improve the precision of the gear. In this case, the gear processing device 1 needs to understand the tooth phase of the workpiece W held by the cage 80 and then align the phases of the workpiece W and the processing tool 42.

In addition, for example, when performing finishing machining using the machining tool 42 on a workpiece W that has been roughly machined using a hob cutter, etc., when machining gears on a workpiece W on which gears have already been formed. There is. In this case as well, the gear processing device 1 grasps the tool phase of the processing tool 42 mounted on the tool holder 43 and the tooth phase of the workpiece W held (fixed) in the cage 80, and It is necessary to perform phase matching between the machining tool 42 and the machining tool 42. Furthermore, the machining tool 42 is a skiving cutter, and has a relatively short tool life compared to, for example, a hob cutter, so that the machining tool 42 must be replaced more frequently. As a result, the gear processing apparatus 1 needs to grasp the tool phase of the processing tool 42 held by the tool holder 43 more frequently.

In this regard, in the gear processing device 1, the workpiece detection sensor 31 and the rotating main shaft 40 to which the tool holder 43 is fixed are provided on the saddle 30 without relative displacement, and the tool detection sensor 64 and the workpiece W are held. The turntable 70 and the like are provided on the tilt table support portion 63 without relative displacement. That is, in the gear processing apparatus 1, the relative position between the workpiece detection sensor 31 and the tool holder 43 is maintained constant, and the relative position between the tool detection sensor 64 and the workpiece W is maintained constant.

The gear processing apparatus 1 of this example first detects the distance by arranging the tool detection sensor 64 at the center position of the tool holder 43, that is, at the first detection position. Thereby, the gear processing device 1 detects the tool phase (rotational position) of the processing tool 42. The gear processing device 1 then moves the saddle 30 in a direction parallel to the X-axis and along the Y-axis toward a second detection position where the workpiece detection sensor 31 detects the tooth phase (rotational position) of the workpiece W. Move it a predetermined distance in a parallel direction. Here, the workpiece detection sensor 31 and the rotating main shaft 40 are supported by the saddle 30 without relative displacement. Therefore, by moving the saddle 30 by a predetermined distance in each direction based on the positional relationship between the rotation main shaft 40 and the workpiece detection sensor 31, the workpiece detection sensor 31 can be placed at the second detection position. can. As a result, the time required for detecting the tooth phase (rotational position) of the workpiece W and for phase alignment between the workpiece W and the machining tool 42 can be shortened.

In the flowchart shown in FIG. 4, the gear machining process executes the phase alignment process in step S4, which is after the hardening process in step S2 and before the finish machining process in step S4. However, the phase alignment process can also be executed during the rough machining process in step S1 and the finish machining process in step S4. For example, if the machining tool 42 is damaged during the rough machining process in step S1 or the finish machining process in step S4 and is replaced, the gear machining process can execute the phase alignment process to align the phase of the machining tool 42 with the workpiece W.

(4. Details of phase alignment of processing tool 42 and workpiece W (gear processing method))
Next, with reference to the flowchart shown in FIG. 5, the phase matching process executed in step S3 in the gear machining process (gear machining method) will be specifically explained. In the position detection process executed in step S3, the control device 100 (specifically, the CPU; the same applies hereinafter) first detects the attachment or replacement of the machining tool 42 by the tool changer 90 in step S11. Determine whether or not it has been performed. In this case, the control device 100 can grasp whether the processing tool 42 has been installed or replaced by communicating with an exchange control section (not shown) of the tool exchange device 90.

Then, if the tool changing device 90 has not installed or replaced the machining tool 42, the control device 100 determines "No" in step S11 and executes the process of step S18. On the other hand, if the tool changing device 90 has installed or replaced the machining tool 42, the control device 100 determines "Yes" in step S11, and executes the process in step S12.

In step S12, the position control unit 104 of the control device 100 controls the drive of the X-axis motor 11, the Y-axis motor 21, and the Z-axis motor 12 to place the tool holder 43 fixed to the tip of the rotating spindle 40 in a preset original position (for example, the position of the rotation axis J before being affected by thermal displacement, etc., as shown in FIG. 1). Then, when the control device 100 has placed the tool holder 43 in the original position, it proceeds to step S13.

(4-1. Index of center position and determination of first detection position)
In step S13 and step S14, the phase detection unit 105 of the control device 100 detects the phase of the processing tool 42, in other words, the rotational position of the cutting edge 42b (or blade groove 42c) of the processing tool 42. determine the first detection position. In this example, in determining the first detection position, the center position of the tool holder 43 is determined. Hereinafter, this indexing of the center position will be specifically explained.

As described above, in the gear processing apparatus 1, the rotating main shaft 40 (including the tool holder 43 and the processing tool 42) and the workpiece detection sensor 31 are supported by the saddle 30 so as not to be relatively movable, and the tilt table support part 63 The tool detection sensor 64 and the workpiece W are supported so as to be immovable relative to each other. Specifically, in the gear processing apparatus 1, the tool detection sensor 64 is fixed to the side surface 63a of the tilt table support part 63 facing the tool holder 43 and the processing tool 42, and the workpiece detection sensor 31 It is fixed to the side surface 30a of the saddle 30 facing the.

When the phase detection unit 105 detects the tool phase (rotational position) of the machining tool 42, the position of the detection groove 43a in the rotational direction is determined based on the change in the distance to the tool holder 43 detected by the tool detection sensor 64. Detect. In this case, as shown in FIG. 6, if the relative positions of the tool detection sensor 64 and the tool holder 43 differ in the direction parallel to the X-axis, the detection accuracy of the detection groove 43a will deteriorate, as shown in FIG. .

For example, at the start of machining the workpiece W, as shown by the solid line in FIG. 6, the tool detection sensor 64 and the tool holder 43 are arranged in series in a direction parallel to the Y-axis; The position of the tool holder 43 in a state where the center position Q of the tool holder 43 is on the center axis of the tool detection sensor 64 is defined as a first detection position. In this case, when the tool detection sensor 64 detects the distance to the tool holder 43 at this first detection position, the detected positional deviation amount L1 becomes "0" as shown in FIG. As a result, as shown in FIG. 7, when detecting the detection groove 43a, the detection groove detection error θ, which is detected with the detection groove 43a shifted in the rotational direction, also becomes "0".

By the way, when the workpiece W is continuously machined, for example, the saddle 30 (column 20) may be thermally displaced with respect to the tilt table support part 63 due to the influence of processing heat accompanying the processing. In this case, even if the position of the saddle 30 in the X-axis direction is controlled to be the first detection position at the start of machining, the broken line in FIG. As shown, the center position Q of the tool holder 43 (rotary main shaft 40) is shifted relative to the center axis of the tool detection sensor 64.

In other words, even if the tool holder 43 (rotary spindle 40) is placed at the same position in the X-axis direction as at the start of machining, the first detection position is when the saddle 30 (column 20) is positioned relative to the tilt table support 63. The detected position is shifted by a detected position shift amount L1 caused by thermal displacement. In this case, based on the distance to the tool holder 43 detected by the tool detection sensor 64, as shown in FIG. It will be detected. As shown in FIG. 7, as the detected positional deviation amount L1 becomes larger, the detection groove detection error θ becomes larger.

Here, the detection groove detection error θ can be expressed by the following equation 1, where the radius of the tool holder 43 is “R” and the distance between the tool holder 43 and the tool detection sensor 64 is “L2”, as shown in FIG.

Therefore, in the gear processing device 1 of this example, as shown by the solid line in FIG. The position of the tool detection sensor 64 (or the tool holder 43 and the rotating main shaft 40) is defined as the first detection position. When the phase detection section 105 detects the detection groove 43a of the tool holder 43, the center position Q of the tool holder 43 is placed on the center axis of the tool detection sensor 64.

Thereby, the relative position between the tool detection sensor 64 and the tool holder 43 can always be kept constant. As a result, the detection groove detection error θ when the phase detection unit 105 detects the detection groove 43a can be reduced to almost “0”.

Therefore, in step S13, in order to detect the center position Q of the tool holder 43, the phase detection section 105 cooperates with the position control section 104 to move the column 20 in the X-axis direction in this example. To specifically explain the process of step S13, for example, with respect to the gear processing apparatus 1 in the state (original position) shown in FIG. 1, as shown in FIG. 8, first, the drive control of the Y-axis motor 21 is performed, The saddle 30 is moved toward the bed 10 (lowered in FIG. 8) in a direction parallel to the Y-axis. Subsequently, the position control section 104 performs drive control of the Z-axis motor 12 to move the table 50, that is, the tilt table support section 63, toward the column 20 in a direction parallel to the Z-axis.

The tool detection sensor 64 of this example is mounted on the tilt table support part 63 via a stay so that the distance detection direction is parallel to the Y axis, that is, in the vertical direction toward the bed 10 (downward in FIG. 8). Fixed. Therefore, the position control unit 104 controls the drive of the Y-axis motor 21 and the Z-axis motor 12 so that the tool holder 43 fixed to the tip of the rotation main shaft 40 is present in the distance detection direction of the tool detection sensor 64. The saddle 30 and table 50 are moved relative to each other.

Subsequently, the position control unit 104 controls the drive of the X-axis motor 11 to move the column 20 in a direction parallel to the X-axis, that is, in a horizontal direction and in the detection direction of the tool detection sensor 64. (first step). As a result, the tool holder 43 fixed to the tip of the rotating main shaft 40 moves linearly with respect to the tool detection sensor 64 in a direction parallel to the X-axis, that is, in a horizontal direction, as shown in FIG. Note that the direction parallel to the X-axis is a direction that is less susceptible to the effects of gravity and thermal displacement than the distance detected by the tool detection sensor 64 in the direction parallel to the Y-axis. Then, when the control device 100 moves the column 20 in a direction parallel to the X-axis, it executes the process of step S14.

In step S14, the phase detection unit 105 determines the center position of the tool holder 43 and determines the first detection position. When the tool detection sensor 64 detects the distance to the tool holder 43 that is moving linearly in the direction parallel to the X-axis through the process of step S13, the detected detection distance D is It changes in a parabola shape with a convex shape. That is, as the position P of the tool holder 43 in the X-axis direction changes sequentially, the detection distance D gradually becomes smaller as the center position Q of the tool holder 43 approaches the tool detection sensor 64. As Q moves away from the tool detection sensor 64, the detection distance D gradually increases. Based on this, the phase detection unit 105 determines the intermediate position P3 in the X-axis direction where the detection distance D is the minimum as the center position Q of the tool holder 43 (second step).

To determine the center position Q, as shown in FIG. 10, the phase detection unit 105 calculates a position P1 where the detection distance D falls below a predetermined threshold D1, and a position P2 where the detection distance D exceeds the predetermined threshold D1. The phase detection unit 105 then calculates, for example, an intermediate position P3 between positions P1 and P2, and determines a position P in the X-axis direction corresponding to the intermediate position P3 ("0" in FIG. 10) as the center position Q in the direction parallel to the X-axis. Note that the tool detection sensor 64 may have a reduced measurement accuracy for distances smaller than the diameter of the tool holder 43, for example. By calculating the intermediate position P3 between positions P1 and P2, the center position Q can be accurately calculated and determined.

Then, the phase detection unit 105 determines the determined center position Q as the first detection position when the tool detection sensor 64 detects the detection groove 43a of the tool holder 43 (that is, the tool phase of the machining tool 42). (third step). In this manner, when the phase detection unit 105 indexes the center position Q of the tool holder 43 and determines the first detection position in step S14 (third step), the control device 100 proceeds to step S15.

Returning to the flowchart of FIG. 5 again, in step S15, the control device 100 (position control unit 104) arranges the tool holder 43 at the first detection position (indexed center position Q) set in step S14. (Third step). That is, as shown in FIG. 11, the position control unit 104 controls the drive of the X-axis motor 11 so that the position of the tool holder 43 in the X-axis direction reaches the first detection position (center position Q) set in step S14. ) The column 20 is moved in a direction parallel to the X-axis line so as to match the position P3 corresponding to the position P3. When the control device 100 places the tool holder 43 at the first detection position, it executes step S16.

In step S16, the control device 100 (phase detection unit 105) detects the tool phase of the cutting edge 42b (third step). In this case, the phase detection section 105 detects the tool phase by cooperating with the tool rotation control section 101.

The phase detection unit 105 detects the detection groove 43a based on the fact that the detection distance D detected by the tool detection sensor 64 disposed at the first detection position has changed by a distance corresponding to the groove depth of the detection groove 43a. can be detected. Based on the predetermined positional relationship between the detection groove 43a of the tool holder 43 and the cutting edge 42b of the processing tool 42, the phase detection unit 105 can detect the tool phase of the cutting edge 42b.

Therefore, as shown in FIG. 11, the tool rotation control unit 101 controls the drive of the spindle motor 41 with the tool detection sensor 64 disposed at the first detection position with respect to the tool holder 43, and controls the rotation of the spindle motor 41. Rotate 40 in one direction at low speed. As a result, the tool holder 43 and the processing tool 42 fixed to the tip of the rotating main shaft 40 also rotate in one direction at low speed. The tool detection sensor 64 detects the detection distance D between the tool holder 43 and the rotating tool holder 43 in this manner.

Then, the phase detection unit 105 detects that the detection groove 43a exists at a rotational position where the detection distance D detected by the tool detection sensor 64 has changed by the groove depth of the detection groove 43a. Thereby, the phase detection unit 105 detects the tool phase of the cutting edge 42b of the processing tool 42 associated with the detection groove 43a.

In addition, when detecting the tool phase, it is not necessary to rotate the rotating main shaft 40, that is, the tool holder 43 multiple times, and it is sufficient to rotate it at least once. Furthermore, in order to further improve the detection accuracy, the rotating main shaft 40 may be first rotated in one direction, and then the rotating main shaft 40 may be rotated in the other direction. Thereby, the change in the detection distance D detected by the tool detection sensor 64, that is, the detection groove 43a, can be detected more reliably, and as a result, the detection accuracy of the tool phase can be improved.

When the tool phase is detected in step S16, the control device 100 executes the process of step S17. That is, in step S17, the control device 100 stores tool phase information representing the detected tool phase, for example, rotational position information representing the rotational position of the rotating spindle 40 detected by the encoder 41a, in the storage device 106. Then, after storing the tool phase information in the storage device 106 in step S17, the control device 100 executes the process of step S18.

In step S18, the control device 100 determines whether the workpiece W has been mounted or replaced. That is, if the workpiece W has not been mounted or replaced, the control device 100 determines "No" in step S18, and executes the process of step S23. On the other hand, if the workpiece W has been mounted or replaced, the control device 100 determines "Yes" in step S18, and executes the process of step S19.

In step S19, the tilt control unit 103 of the control device 100 controls the drive of the A-axis motor 61, and swings the tilt table 60 so that the C-axis, which is the rotation axis of the workpiece W, and the rotation axis J of the machining tool 42 (rotating spindle 40) are parallel, as shown in FIG. 11. Then, after swinging the tilt table 60, the control device 100 proceeds to step S20.

In step S20, the phase detection unit 105 of the control device 100 determines the positional relationship between the workpiece detection sensor 31 in the saddle 30 and the rotating main shaft 40, and the center position Q of the tool holder 43 determined in step S14. Based on this, the second detection position of the workpiece detection sensor 31 is determined (fourth step). Then, the position control unit 104 of the control device 100 arranges the workpiece detection sensor 31 at the second detection position (fourth step).

Specifically, the position control unit 104 controls the column 20 in which the tool holder 43 (rotary spindle 40) is located at the first detection position as shown in FIG. 11, and the workpiece detection sensor 31 as shown in FIG. is moved toward a second detection position where the tooth phase of the workpiece W is detected. That is, the position control unit 104 controls the drive of the X-axis motor 11 to move the column 20 (saddle 30 and workpiece detection sensor 31) in a direction parallel to the X-axis. Further, the position control unit 104 controls the drive of the Y-axis motor 21 to move the column 20 (saddle 30 and workpiece detection sensor 31) in a direction parallel to the Y-axis. As a result, the position control unit 104 finally places the workpiece detection sensor 31 at the second detection position, as shown in FIG.

Here, the rotating main shaft 40 and the workpiece detection sensor 31 are supported so as not to be relatively movable with respect to the saddle 30. Further, as described above, the first detection position is determined based on the center position Q determined by linearly moving the tool holder 43 in a direction parallel to the X-axis. Thereby, the first detection position is determined while eliminating the influence of thermal displacement of the saddle 30 (column 20) and the tilt table support section 63.

That is, even if the tilt table support part 63 is thermally displaced with respect to the saddle 30, the first detection position is determined by excluding the thermal displacement of the tilt table support part 63. Here, as shown in FIG. 11, the saddle 30 is arranged so that the tool detection sensor 64 corresponds to the first detection position, and supports the rotating main shaft 40 and the workpiece detection sensor 31 so that they cannot move relative to each other. There is.

As shown in FIG. 13, when this saddle 30 is moved to correspond to the second detection position of the workpiece detection sensor 31, the positional relationship between the rotating main shaft 40 and the workpiece detection sensor 31 is maintained. Therefore, the positional relationship between the workpiece W and the workpiece detection sensor 31 can be kept unchanged regardless of the presence or absence of thermal displacement. That is, in the gear processing device 1, when detecting the tooth phase of the workpiece W, the saddle 30 is adjusted based on the center position Q as a reference and the positional relationship between the rotating main shaft 40 and the workpiece detection sensor 31. It is moved by a preset distance in a direction parallel to the X-axis, and it is also moved by a preset distance in a direction parallel to the Y-axis.

Thereby, the workpiece detection sensor 31 can be moved to the second detection position where the relative position with respect to the workpiece W is the same. As a result, in the gear processing apparatus 1, the tooth phase (rotational position) can be detected without determining the center position of the workpiece W.

Returning to the flowchart of FIG. 5 again, in step S21, the phase detection unit 105 of the control device 100 detects the tooth phase (rotational position) of the workpiece W (fourth step). In this case, the phase detection unit 105 detects the tooth phase (rotational position) of the workpiece W by cooperating with the workpiece rotation control unit 102.

As shown in FIG. 13, the workpiece rotation control unit 102 operates the C-axis motor 62 in a state where the workpiece detection sensor 31 is placed at the second detection position by the telescoping mechanism under the drive control of the position control unit 104, for example. Drive control is performed to rotate the workpiece W in one direction at low speed. In this example, the workpiece detection sensor 31 outputs a signal (eg, voltage) corresponding to the bottom surface of the workpiece W.

As a result, the phase detection unit 105 detects the tooth phase of the workpiece W based on the signal output by the workpiece detection sensor 31 and the rotation angle information of the workpiece W obtained from the encoder 62a. Then, when the control device 100 detects the tooth phase of the workpiece W, it executes the process of step S22.

In step S22, when determining the tooth phase of the workpiece W, the phase detection unit 105 uses the output voltage information obtained from the workpiece detection sensor 31 and the workpiece The tooth phase of the workpiece W is calculated based on the rotation angle information of the workpiece W.

As shown in FIG. 14, the change in voltage output from the workpiece detection sensor 31 is a sine waveform that periodically rises and falls with the change in the rotation angle of the workpiece W. The phase detection unit 105 sets the intermediate value between the maximum and minimum values of the voltage as the second threshold value Th1, and extracts the rotation angle θ11 of the workpiece W when the voltage falls below the second threshold value Th1, and the rotation angle θ12 of the workpiece W when the voltage rises above the second threshold value Th1. The phase detection unit 105 then calculates the rotation angle θ1 that is the intermediate value between the rotation angles θ11 and θ12.

This rotation angle θ1 can be regarded as the rotation angle of the workpiece W when the second detection position of the workpiece detection sensor 31 and the center position of the bottom surface of the gear of the workpiece W coincide. The phase detection unit 105 calculates the tooth phase at the center position of the tooth bottom surface based on the calculation result and the basic gear information stored in the storage device 106. The phase detection unit 105 stores information regarding the tooth phase at the center position of the tooth root surface obtained by calculation in the storage device 106 as a detection result of the workpiece detection sensor 31. Then, when the control device 100 stores tooth phase information representing the detected tooth phase (rotational position) of the workpiece W in the storage device 106, it executes the process of step S23.

In addition, when detecting the tooth phase, it is not necessary to rotate the workpiece W a plurality of times, and the workpiece W may be rotated by at least one rotation or by a rotation angle of less than 360 degrees. Furthermore, in order to further improve the detection accuracy, the workpiece W may first be rotated in one direction, and then the workpiece W may be rotated in the other direction.

In step S23, the phase detection unit 105 of the control device 100 determines the tooth phase of the workpiece W and the processing The amount of tool phase shift of the tool 42 is calculated. The phase detection section 105 cooperates with the tool rotation control section 101 and the workpiece rotation control section 102 to align the phases of the workpiece W and the processing tool 42 based on the calculated amount of deviation.

The phase detection unit 105 determines the tooth phase of the workpiece W and the machining tool 42 based on the information stored in the storage device 106, that is, the detection result of the workpiece detection sensor 31 and the detection result of the tool detection sensor 64. Calculate the amount of deviation from the tool phase. Then, the tool rotation control unit 101 and the workpiece rotation control unit 102 control the workpiece W so that the tooth phase of the workpiece W and the tool phase of the machining tool 42 match based on the amount of deviation obtained by calculation. and adjust the rotation angle of the processing tool 42. When the control device 100 finishes adjusting the rotation angles of the workpiece W and the machining tool 42, that is, adjusting the machining initial position by phase matching, the control device 100 returns to the gear machining process shown in FIG. 4.

As can be understood from the above description, according to the gear processing apparatus 1, the phase detection unit 105 detects the center position Q of the tool holder 43 constituting the rotating main shaft detected by the tool detection sensor 64 as a tool detection sensor. (Intermediate position P3 between position P1 and position P2 in FIG. 10) is determined. Then, the phase detection unit 105 detects the tool detection sensor 64 using the center position Q (intermediate position P3) of the tool holder 43 only by calculating and indexing the center position Q (intermediate position P3) of the tool holder 43. The first detection position and the second detection position of the workpiece detection sensor 31 can be determined.

That is, by simply determining the center position Q (intermediate position P3) of the tool holder 43, there is no need to separately detect the center position of the workpiece W. This makes it possible to omit the step of detecting the center position of the workpiece W, for example, when mounting or replacing the processing tool 42 or the workpiece W, or even when thermal displacement occurs. Therefore, the complicated work of determining the center position of each of the machining tool 42 and the workpiece W does not occur, and the time required to determine the center position of the workpiece W is not required, which reduces the cycle time required for machining. It becomes possible to shorten the time.

(5. Others)
In this example described above, the rotation main shaft 40 (rotation main shaft body including the processing tool 42 and tool holder 43) of the gear processing device 1 is parallel to the X-axis line that is perpendicular to the rotation axis J that extends in the direction parallel to the Z-axis line. In other words, it is moved in the horizontal direction, that is, in the direction across which the rotating main shaft body crosses. However, the direction in which the rotating main shaft 40 (including the processing tool 42 and the tool holder 43) is moved is not limited to the direction parallel to the X-axis line, as long as it is a "direction that the rotating main shaft crosses". For example, moving the rotating main shaft 40 (including the processing tool 42 and the tool holder 43) in a direction parallel to the Y-axis, that is, a vertical direction, a direction parallel to the Z-axis, or a direction oblique to the rotation axis J. It is also possible to do so.

Even in these cases, the center position of the tool holder 43 (rotary main shaft 40) can be determined based on the detection distance D detected by the tool detection sensor 64. Therefore, the same effects as in this example described above can be expected. In particular, when moving the rotating main shaft 40 (including the processing tool 42 and the tool holder 43) in a direction parallel to the Y-axis, that is, in a vertical direction, the influence of thermal displacement is a factor that causes the center position to shift. In addition to this, there is also the effect of gravity.

Therefore, in this case, it is preferable to correct the shift in the center position due to the influence of gravity, for example, by calculation. Here, when correcting the influence of gravity, for example, using the detection result of the tool detection sensor 64 whose detection direction is in the vertical direction and the detection result of the tool detection sensor 64 whose detection direction is in the horizontal direction, It is also possible to determine the center position. This makes it possible to index the center position with higher precision.

Further, in the present example described above, the phase detection unit 105 determines the first detection position to coincide with the indexed center position Q of the tool holder 43. Instead, a first detection position different from the center position Q may be determined based on the indexed center position Q of the tool holder 43, if necessary. Even in this case, the first detection position can be determined based on the center position Q of the tool holder 43, for example, while eliminating the influence of thermal displacement.

In addition, in this example described above, the column 20 (saddle 30) of the gear processing device 1 moves in a direction parallel to the X-axis and also moves in a direction parallel to the Y-axis, and the table 50 (tilt table support section 63) moves in a direction parallel to the Y-axis. is now moved in a direction parallel to the Z-axis. Instead of this, for example, the table 50 is fixed to the bed 10 so as not to be movable, and the column 20 (saddle 30) is moved in a direction parallel to the X axis, a direction parallel to the Y axis, and a direction parallel to the Z axis. It is also possible to configure it to move.

Even if the gear processing apparatus 1 is configured in this way, the saddle 30, that is, the workpiece detection sensor 31, and the rotating main shaft 40 (including the processing tool 42 and the tool holder 43) It is possible to change the relative position of the tilt table support part 63, that is, the tool detection sensor 64, and the workpiece W. Therefore, even in this case, the same effects as in this example described above can be obtained.

In addition, in this example described above, the tool detection sensor 64 detects the distance to the outer peripheral surface of the tool holder 43 that is moving in the direction parallel to the X-axis, that is, in the "direction across the rotating main shaft". , the center position Q of the tool holder 43 is determined. Instead, the tool detection sensor 64 detects the distance to the outer circumferential surface of the rotational spindle 40 that is moving in a direction parallel to the It is also possible to determine the center position of Alternatively, the cutting edge of the processing tool 42 can be detected by the tool detection sensor 64 detecting the distance to the outer peripheral surface of the processing tool 42 that is moving in a direction parallel to the It is also possible to directly index the tool phase of 42b. In this way, even when determining the center position of the rotating main shaft 40 and the tool phase of the machining tool 42, the same effects as in this example described above can be obtained.

Further, in this example described above, the tool detection sensor 64 as a tool detection sensor detects the distance to the rotating main shaft body, and the workpiece detection sensor 31 detects the distance to the workpiece W. The physical quantities detected by the tool detection sensor and workpiece detection sensor are not limited to distance; for example, the tool detection sensor and workpiece detection sensor detect the strength and weakness of electromagnetic physical quantities and the direct displacement of a contact. You may do so.

Furthermore, in the present example described above, the gear processing device 1 is equipped with the tool exchange device 90, so that the processing tool 42 can be automatically exchanged according to the content of processing on the workpiece W. However, the gear processing device 1 does not necessarily need to include the tool exchange device 90, and it is also possible to configure the gear processing device 1 without the tool exchange device 90.

In this way, even if the tool exchange device 90 is omitted, the machining tool 42 is manually replaced, for example, when the machining tool 42 becomes worn or damaged. Even when the machining tool 42 is replaced manually, the same effect as in this example can be obtained by indexing the center position Q of the tool holder 43 as described above.

Further, in the present example described above, a case where only the workpiece detection sensor 31 is fixed to the saddle 30 of the gear processing device 1 is illustrated. However, it goes without saying that it is possible to provide the saddle 30 with a sensor other than the workpiece detection sensor 31 that detects the machining state of the workpiece W. In this case as well, by using the detection result by the tool detection sensor 64 to determine the detection position of other sensors, the center position of the workpiece W is separately assigned to determine the detection position of the other sensor. There's no need to take it out. Therefore, even in this case, the same effects as in this example described above can be obtained.

Furthermore, in the present example described above, the processing tool 42 is a skiving cutter, and the gear processing apparatus 1 performs gear processing by skiving processing. On the other hand, when the processing tool is a hob cutter, the gear processing device can perform gear processing by hobbing.

In this case, in the gear processing device, the hob cutter and the workpiece are arranged such that the rotational axis of the hob cutter and the rotational axis of the workpiece intersect (for example, are orthogonal to each other). During gear machining, a gear machining device processes a gear on a workpiece by sending (relatively moving) the hob cutter in the rotational axis direction while rotating the workpiece and the hob cutter.

Then, when replacing the machining tool, the gear machining device detects the tool phase of the hob cutter and the tooth phase of the workpiece to match the phases of the workpiece and the hob cutter, similarly to the present example described above. As a result, when gear machining is performed by hobbing using a hob cutter, the gear machining device can, for example, protect the workpiece even when installing or replacing the hob cutter or workpiece, or even when thermal displacement occurs. The step of detecting the center position of can be omitted. Therefore, in this case as well, as in the present example described above, the complicated work of determining the respective center positions of the hob cutter and the workpiece is not required, and the time required to determine the center position of the workpiece is not required. Therefore, it is possible to shorten the cycle time required for processing.

DESCRIPTION OF SYMBOLS 1... Gear processing device, 10... Bed, 11... X-axis motor, 12... Z-axis motor, 20... Column (tool holding device), 20a... Side (sliding surface), 21... Y-axis motor, 30... Saddle ( Tool holding device), 30a... Side surface, 31... Workpiece detection sensor, 40... Rotating spindle (rotating spindle body), 41... Spindle motor, 41a... Encoder, 42... Machining tool (rotating spindle body), 42a... Tool blade , 42b...Blade tip, 42c...Blade groove, 43...Tool holder (rotating main shaft body), 43a...Detection groove, 50...Table, 60...Tilt table, 61...A-axis motor, 62...C-axis motor, 62a...Encoder, 63... Tilt table support part (workpiece support device), 63a... Side surface, 64... Tool detection sensor, 70... Turntable (workpiece support device), 80... Holder (workpiece support device), 90... Tool change device , 100...Control device, 101...Tool rotation control section, 102...Workpiece rotation control section, 103...Tilt control section, 104...Position control section, 105...Phase detection section, 106...Storage device, W...Workpiece, L1 ...Detection position deviation amount, L2...Distance between tool holder and tool detection sensor, θ...Detection groove detection error, D...Detection distance, D1...Threshold value, P3...Intermediate position, Q...Center position

Claims (10)

A gear processing device that generates teeth by relatively feeding a processing tool and a workpiece while rotating them synchronously, and cutting the peripheral surface of the workpiece, the gear processing device comprising:
a tool holding device that rotatably holds the processing tool;
a workpiece holding device that rotatably holds the workpiece;
a workpiece detection sensor provided in the tool holding device to detect the rotational position of teeth of the workpiece held by the workpiece holding device;
a tool detection sensor that is provided on the workpiece holding device and detects a rotational position of a tool blade formed on the processing tool held by the tool holding device;
a position control unit that controls the positions of the tool holding device and the workpiece holding device such that they can move relative to each other, and a tool phase of the machining tool, a tooth phase of the workpiece, or a tool phase of the machining tool and the a control device including a phase detection unit that detects both the tooth phase of the workpiece;
Equipped with
The phase detection section is
The detection result detected by the tool detection sensor by the position control unit relatively moving the tool holding device in a direction that the rotating main shaft including the processing tool crosses with respect to the detection direction of the tool detection sensor. Determining the center position of the rotating main shaft body based on
Determining a first detection position where the tool detection sensor is placed using the center position, and based on the detection result of the tool detection sensor placed at the first detection position by the position control by the position control unit. detecting the tool phase of the processing tool, or
The phase detection section is
The position control unit moves the tool holding device relative to the detection direction of the tool detection sensor in a direction across which the rotating main shaft body including the machining tool crosses, thereby adjusting the detection result detected by the tool detection sensor. determining the center position of the rotating main shaft body based on the
A second detection position at which the workpiece detection sensor is placed is determined using the center position and the positional relationship between the rotating main shaft body and the workpiece detection sensor, and the second detection position is determined by the position control by the position control unit. detecting the tooth phase of the workpiece based on the detection result of the workpiece detection sensor arranged at a second detection position, or
The phase detection section is
The position control unit moves the tool holding device relative to the detection direction of the tool detection sensor in a direction across which the rotating main shaft body including the machining tool crosses, thereby adjusting the detection result detected by the tool detection sensor. determining the center position of the rotating main shaft body based on the
Determining a first detection position where the tool detection sensor is placed using the center position, and based on the detection result of the tool detection sensor placed at the first detection position by the position control by the position control unit. detecting the tool phase of the processing tool;
A second detection position at which the workpiece detection sensor is placed is determined using the center position and the positional relationship between the rotating main shaft body and the workpiece detection sensor, and the second detection position is determined by the position control by the position control unit. detecting the tooth phase of the workpiece based on the detection result of the workpiece detection sensor placed at the detection position;
Gear processing equipment. Gear processing according to claim 1, wherein the detection direction in which the tool detection sensor detects the rotational position of the tool blade and the detection direction in which the workpiece detection sensor detects the rotational position of the tooth are the same direction. Device. The detection direction in which the tool detection sensor detects the rotational position of the tool blade and the detection direction in which the workpiece detection sensor detects the rotational position of the tooth are defined by the rotational main axis relative to the detection direction of the tool detection sensor. The gear processing device according to claim 2, wherein the direction is perpendicular to the direction in which the body traverses. The gear according to any one of claims 1 to 3, wherein the phase detection unit determines the center position affected by thermal displacement occurring between the tool holding device and the workpiece holding device. Processing equipment. The gear processing device according to claim 4, wherein the phase detection section determines the center position affected by the thermal displacement that occurs in a direction transverse to the detection direction of the tool detection sensor. . A bed supporting the tool holding device and the workpiece holding device is arranged horizontally, and the tool detection sensor is supported by the workpiece holding device so that the detection direction of the tool detection sensor is vertical. In the case where
The gear processing apparatus according to claim 5, wherein the phase detection section determines the center position based on the thermal displacement occurring in the horizontal direction. The tool detection sensor is supported immovably relative to the workpiece ,
The gear processing apparatus according to any one of claims 1 to 6, wherein the workpiece detection sensor is supported so as to be immovable relative to the rotating main shaft . The tool detection sensor detects the rotational position of the tool blade based on the distance to the rotating main shaft,
The gear processing apparatus according to any one of claims 1 to 7, wherein the workpiece detection sensor detects the rotational position of the tooth based on a distance to the workpiece. The workpiece detection sensor is movably provided integrally with the tool holding device, and is movable toward the workpiece held by the workpiece holding device in a direction parallel to the axis of the rotating main shaft. A gear processing device according to any one of claims 1 to 8, wherein the gear processing device is provided. A gear machining method in which a machining tool is rotated synchronously with a workpiece and relatively fed, thereby cutting the circumferential surface of the workpiece and creating teeth on the circumferential surface, the method comprising:
a tool holding device that rotatably holds the processing tool;
a workpiece holding device that rotatably holds the workpiece;
a workpiece detection sensor provided in the tool holding device to detect the rotational position of teeth of the workpiece held by the workpiece holding device;
a tool detection sensor that is provided on the workpiece holding device and detects a rotational position of a tool blade formed on the processing tool held by the tool holding device;
a position control unit that controls the positions of the tool holding device and the workpiece holding device so that they can move relative to each other, and a position control unit that controls the position of the processing tool based on the detection result of the tool detection sensor and the detection result of the workpiece detection sensor Applied to a gear processing device comprising a control device including a phase detection unit that detects a tool phase and a tooth phase of the workpiece,
a first step in which the position control unit moves the tool holding device in a direction that a rotating main shaft including the processing tool crosses with respect to a detection direction of the tool detection sensor;
a second step in which the phase detection unit determines the center position of the rotating main shaft based on a distance to an outer circumferential surface of the rotating main shaft detected by the tool detection sensor as the rotating main shaft moves; ,
The phase detection unit determines a first detection position at which the tool detection sensor is placed using the center position, and the tool detection sensor is placed at the first detection position by the position control by the position control unit. a third step of detecting the tool phase of the processing tool based on the detection result;
The phase detection section determines a second detection position at which the workpiece detection sensor is placed using the center position and the positional relationship between the rotating main shaft body and the workpiece detection sensor, and also determines the second detection position at which the workpiece detection sensor is placed. a fourth step of detecting the tooth phase of the workpiece based on the detection result of the workpiece detection sensor placed at the second detection position by position control;
Gear processing methods, including:

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