JP7267585B2 - Gear processing equipment - Google Patents

Description

The present invention relates to a gear machining apparatus.

Conventionally, honing, for example, is known as finish machining for gears. In these processes, the gear to be processed and the grindstone gear are engaged with each other and rotated to perform finishing.

For example, Patent Literature 1 describes a gear processing device that performs honing processing. In this device, a workpiece, which is a gear to be machined, is supported by being sandwiched from both ends in the axial direction by a workpiece support unit consisting of a headstock and a tailstock. is engaged with the workpiece. By rotating the tool of the tool support unit in this state, the workpiece and the tool are rotated together to machine the workpiece.

Japanese Patent No. 2880407

By the way, in the tool support unit of the gear machining apparatus, an internal gear-shaped tool is mounted via bearings, and the bearings may fail due to, for example, lack of lubricating oil or abnormal loads. If a bearing breaks down, it will take a long time to repair it, and during that time, machining will stop, which may interfere with the production schedule. In addition, when a failure suddenly occurs, it is difficult to secure personnel to deal with the failure, which further prolongs the suspension period of machining. Therefore, it is desired to predict bearing failure in advance, but such a gear machining apparatus has not yet been proposed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gear machining apparatus capable of determining the condition of a bearing.

A gear machining apparatus according to the present invention comprises: a workpiece support unit that rotatably supports a gear to be machined by the gear machining apparatus; and a tool housing that rotatably supports an internal gear-shaped tool that meshes with the gear to be machined via a bearing. and vibration measuring means provided in the tool housing for measuring vibration generated in the bearing, and acquiring vibration measurement data measured by the vibration measuring means, and obtaining vibration reference data and the vibration measurement data as a reference of vibration. and a control unit that calculates the state of the bearing based on the comparison with.

In the gear machining apparatus, the control unit is configured to output a judgment that an abnormality has occurred in the bearing when the vibration measurement data satisfies a predetermined condition in comparison with the vibration reference data. can do.

The gear machining apparatus may further include temperature measuring means for measuring the temperature of the bearing, which is provided in the tool housing, and the control unit acquires temperature measurement data measured by the temperature measuring means, The state of the bearing can be calculated based on a comparison between the temperature reference data that serves as a reference for the temperature measurement data and the temperature measurement data.

The gear machining apparatus may further include outside temperature measuring means for measuring an outside temperature, and the control unit may be configured to calculate the state of the bearing by referring to the outside temperature. can.

In the gear machining apparatus, the bearing may include an outer ring, an inner ring, and a plurality of rolling elements arranged between the outer ring and the inner ring, and the internal gear-shaped tool is fixed to the inner ring. and the vibration measuring means can be attached to the tool housing in contact with the outer ring.

According to the gear machining apparatus of the present invention, it is possible to determine the state of the bearing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows one Embodiment of the gear processing apparatus which concerns on this invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 3 is a cross-sectional view taken along line BB of FIG. 2; 4 is an enlarged sectional view of FIG. 3; FIG. FIG. 5 is an enlarged view of FIG. It is time-series data showing the level of bearing vibration. 4 is a flow chart for determining bearing abnormality.

An embodiment of a gear machining apparatus according to the present invention will be described below with reference to the drawings. 1 is a front view of this gear machining apparatus, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is a view taken along the line BB of FIG. 1, and FIG. 4 is an enlarged sectional view of FIG. In the following description, the left-right direction in FIG. 1 is called the X-axis direction, the up-down direction in FIG. 1 is called the Z-axis direction, and the left-right direction in FIG. 2 is called the Y-axis direction. The description will be based on the display of directions (up, down, front, back, left, and right) shown together with the marks of the X, Y, and Z axes. However, these orientations are in one aspect of the present invention, and other arrangements are possible, so they are not limited to these orientations.

<1. Overview of gear processing equipment>
As shown in FIGS. 1 to 3, the gear machining apparatus according to the present embodiment includes a base 1, a tool support unit 2 and a work support unit 3 arranged thereon, and a control unit for controlling the drive of the apparatus. a part 4; The tool support unit 2 has a support 21 and a tool housing 22 connected to the front of the support and having an internal gear-shaped tool (grinding wheel) 236 mounted thereon. It is arranged so as to face in the X-axis direction. As a result, the tool 236 meshes with the gear to be machined, which is the workpiece W. As shown in FIG.

On the other hand, the work support unit 3 is composed of a headstock 31 and a tailstock 32 for clamping the work W, and these are arranged on both sides of the base 1 with the tool support unit 2 interposed therebetween. Each unit 2 and 3 will be described in detail below.

<2. Tool support unit>
First, the tool support unit 2 will be described in detail. As shown in FIG. 2, the support 21 described above is provided with a shaft member 211 extending in the Y-axis direction, and the tool housing 22 is attached to the front side of this shaft member 211 . Since the shaft member 211 is rotatably supported around the Y axis, when the shaft member 211 rotates, the tool housing 22 rotates around the Y axis. Thereby, the work W can be given a crossing angle.

Although not shown, the support 21 can reciprocate on the base 1 in the Y-axis direction, so that the tool 222 can cut the workpiece W. there is Although the means for moving the support 21 is not particularly limited, for example, the support 21 is movably supported on rails arranged on the base 1 and extending in the Y-axis direction, and a known device such as a ball screw, nut, and motor is used. can be moved along the rail by means of

Next, the tool housing 22 will be described with reference to FIG. 4 as well. As shown in FIGS. 2 and 3, the tool housing 22 has an annular support portion 221 connected to the shaft member 211 described above. placed to face. An annular internal gear-shaped tool 222 is rotatably attached to the inner peripheral surface of the support portion 221 via a bearing 23 . Then, the work W is engaged with the tool 222 from the inside, and the work W is machined while the tool 222 rotates together. As shown in FIG. 4 , a drive gear 223 is attached to the outer peripheral surface of the tool 222 , and this drive gear 223 is rotated by a motor 224 fixed to the upper portion of the support portion 221 . That is, a speed reducer (not shown) is provided between the motor 224 and the driving gear 223, so that when the motor 224 is driven, the driving gear 223 rotates together with the tool 222 at a predetermined speed reduction ratio. . Also, the motor 224 is electrically connected to the control unit 4 so that the motor 224 is driven. Also, a signal indicating the rotation speed, temperature, torque command value, load value, voltage, current, etc. of the motor 224 during machining is transmitted to the control unit 4 .

The pair of bearings 23 described above are attached to the outer peripheral surface of the tool 222 so as to sandwich the drive gear 223 in the axial direction. Each bearing 23 is a known one and includes an inner ring 231 , a retainer (not shown), a plurality of rolling elements 232 and an outer ring 233 . An outer ring 233 of the bearing 23 is fixed to the inner peripheral surface of the support portion 221 .

Further, as shown in FIG. 4 , the supporting portion 221 is provided with a known vibration measuring sensor 5 for measuring vibration of each bearing 23 , and the vibration measuring sensor 5 is electrically connected to the control portion 4 . It is More specifically, the supporting portion 221 is formed with a pair of radially extending first through holes 226 at positions corresponding to the bearings 23, and the vibration measuring sensor 5 is inserted into each of the first through holes 226. It is Each vibration measuring sensor 5 is provided with a vibration sensor 51 , and this vibration sensor 51 is arranged so as to be in contact with the outer ring 233 of the bearing 23 . In order to accurately measure the vibration of the bearing 23, the vibration sensor 51 needs to be arranged so as to face the center of rotation of the bearing 23, that is, the axial center of the tool 222. FIG. Therefore, the first through hole 226 is formed along the radial direction of the tool 222 so as to face the axial center of the tool 222 . As a result, each vibration measuring sensor 5 measures the vibration generated in the bearing 23 during machining and transmits it to the control unit 4 .

Further, as shown in FIG. 1, the supporting portion 221 is provided with a known temperature measuring sensor 6 for measuring the temperature of each bearing 23, and this temperature measuring sensor 6 is electrically connected to the control portion 4. It is More specifically, the supporting portion 221 is formed with a pair of second through holes (not shown) extending in the radial direction at positions corresponding to the bearings 23, and the temperature measurement sensor 6 is inserted into each second through hole. is inserted. Each temperature measurement sensor 6 is arranged so as to be in contact with the outer ring 233 of the bearing 23 . The second through hole is formed at a position apart from the first through hole 226 in the circumferential direction of the support portion 221 . Thereby, each temperature measuring sensor 6 measures the temperature of the bearing 23 during machining and transmits this to the control section 4 .

<3. Work support unit>
Next, the work support unit 3 will be explained. As shown in FIGS. 1 and 3, the work support unit 3 is composed of the headstock 31 and the tailstock 32 described above. is arranged, and a tailstock 32 is arranged on the right side. The headstock 31 and the tailstock 32 are arranged close to each other in the X-axis direction so as to rotatably hold the workpiece W therebetween. The headstock 31 is provided with a first shaft member 311 that engages with the work and extends in the X-axis direction. It is designed to

The headstock 31 is arranged on a first guide rail 15 arranged on the base 1 and extending in the X-axis direction, and moves along the first guide rail 15 . A nut (not shown) is fixed to the lower part of the headstock 31, and a ball screw (not shown) is screwed into this nut. The ball screw extends in the X-axis direction and is connected to a motor (not shown) fixed to the base 1 . Therefore, when the motor is driven, the ball screw rotates, and accordingly the headstock 31 moves in the X-axis direction.

The tailstock 32 is also constructed in the same manner as the headstock 31 . That is, the tailstock 32 is provided with a second shaft member 321 that engages with the first shaft member 311 of the headstock 31 and extends in the X direction, and this second shaft member 321 rotates around the X axis. freely supported. The tailstock 32 is arranged on the second guide rail 16 arranged on the base 1 and extending in the X-axis direction, and moves along the second guide rail 16 . Like the headstock 31, the tailstock 32 is also driven by a nut, a ball screw, and a motor (not shown) to move in the X-axis direction.

As shown in FIG. 3, the work W is supported by the headstock 31 and the tailstock 32, and the work W is also moved in the X-axis direction by synchronous movement of the headstock 31 and the tailstock 32 in the X-axis direction. It is designed to move in the axial direction.

<4. Control section>
Next, the controller 4 will be described with reference to FIG. As shown in FIG. 5, the control unit 4 can be composed of a PLC or a general-purpose computer having a CPU 41, a RAM (not shown), and a storage unit 42, and controls various drives of the gear machining apparatus. It's becoming Also, the controller 4 is electrically connected to an outside air temperature sensor 7 for measuring the temperature of the outside air outside the device, so that the outside air temperature can be obtained.

In particular, the control unit 4 receives signals related to various data measured by the motor 224, the vibration measurement sensor 5, the temperature measurement sensor 6, and the outside air temperature sensor 7. Abnormality of the bearing 23 is determined. This point will be described in detail below.

As shown in FIG. 5, the storage unit 42 of the control unit 4 stores an abnormality determination program 421 for determining occurrence of an abnormality, and the CPU 41 executes this program 421 . In addition, the storage unit 42 stores motor data 422 that stores the number of revolutions and torque of the motor 224, vibration measurement data 423 that is measured by the vibration measurement sensor 5, temperature measurement data 424 that is measured by the temperature measurement sensor 6, and outside air temperature data 425 measured by an outside air temperature sensor. Furthermore, in this storage unit 42, data related to vibration generated from a normal bearing 23 during machining is measured in advance by the vibration measuring sensor 5 and stored as vibration reference data 426. FIG. Similarly, data relating to the temperature during processing of the normal bearing 23 is measured in advance by a temperature measuring sensor and stored as temperature reference data 427 .

The control unit 4 acquires vibration measurement data 423 and temperature measurement data 424 during processing, compares them with vibration reference data 426 and temperature reference data 427, and determines whether the bearing 23 is abnormal. As described above, the bearing 23 is mainly composed of the inner ring 231, the retainer, the rolling elements 232, and the outer ring 234. Damage to any one of these may cause the bearing 23 to malfunction. For example, if lubricating oil is insufficient or an abnormal load is generated in the bearing 23, one of the above-mentioned members will be worn and smooth rotation will not be possible. As a result, vibration of a specific periodic component occurs in the bearing 23 .

For example, FIG. 6 shows time-series vibration measurement data at a certain frequency, overlaid with vibration reference data. Since the specific frequency at which a bearing failure occurs varies depending on the rotation speed of the tool 222, the rotation speed of the tool 222 is calculated based on the rotation speed obtained from the motor 224 as described above. Then, a specific frequency corresponding to the number of revolutions is analyzed. The horizontal axis of FIG. 6 is time, and the vertical axis is a value indicating vibration (hereinafter referred to as vibration value). The vibration value is calculated with 1 being the specific frequency that occurs in a normal bearing. That is, in this graph, the vibration value of the vibration reference data is calculated as approximately 1, and the vibration value calculated from the vibration measurement data 423 is shown correspondingly. According to this graph, the vibration measurement data 423 indicates a vibration value of 1 or more, and there is a deviation from the vibration reference data 426 . A threshold for determining the occurrence of an abnormality can be appropriately determined depending on the type of workpiece, the type of machining, and the like. 6, for convenience of explanation, the vibration reference data 426 measured in time series are superimposed, so the vibration reference data 426 in FIG. 6 slightly fluctuates from 1. Also, the vibration reference data 426 can be converted into a vibration value within a predetermined range instead of the vibration value at one point.

For example, if the vibration value of the vibration measurement data 423 is 3 or more, it is not necessary to replace the bearing 23, but there is a slight tendency to be abnormal. is increasing, it is judged that the bearing 23 needs to be replaced soon, and if it is 5 or more, it is judged that the bearing 23 needs to be replaced immediately because the machining accuracy of the work W is affected. , etc. can be set. By providing such a reference, occurrence of an abnormality in the bearing 23 can be predicted.

The above is the handling of the vibration of the bearing 23, but the temperature can be similarly set. For example, damage to the parts that make up the bearing 23 can result in excessive metal-to-metal contact and elevated temperatures. Therefore, by measuring the temperature of the bearing 23 and comparing it with the temperature reference data 427 that serves as a reference, the failure of the bearing 23 can be determined. A threshold value for determining the occurrence of an abnormality can be appropriately set according to the type of workpiece, etc., in the same manner as the vibration described above. The temperature of the bearing 23 is also affected by the outside air, and may change depending on the season, for example. Therefore, the control unit 4 can appropriately change the threshold while taking the outside temperature data 425 into consideration.

The occurrence of an abnormality in the bearing 23 is determined mainly by vibration, and may be determined by temperature. For example, it is possible to make a judgment based on temperature only when no abnormality is found in vibration, and it is possible to judge that an abnormality has occurred in the bearing 23 when abnormality is found in temperature. In addition, changes in the torque command value, load value, voltage, current, etc., obtained from the motor 224 can be used as supplementary criteria for determining whether the bearing 23 is abnormal. However, the determination of abnormality can be set in various ways, and is not limited to this.

<5. Operation of Gear Machining Device>
Next, the operation of the gear machining apparatus configured as described above will be described with reference to FIG. 7 as well. First, the workpiece W is attached to the tip of the first shaft member 311 of the headstock 31 . Next, the tool housing 22 of the tool support unit 2 is rotated around the Y-axis and positioned so as to form a predetermined crossing angle on the workpiece W. FIG. Subsequently, the headstock 31 and the tailstock 32 are brought close to each other, and the workpiece W is fixed. In this state, the first shaft member 311 of the headstock 31 is rotated together with the work W. As shown in FIG. In parallel with this, the motors 224 and 312 are driven to rotate the tool 236 of the tool support unit 2 so as to synchronize with the workpiece W. As shown in FIG. Subsequently, the support 21 is moved in the Y-axis direction to bring the tool 236 closer to the workpiece W. As shown in FIG. Then, the workpiece W is machined by meshing the workpiece W and the tool 236 and rotating them together.

By the way, in the present embodiment, as shown in FIG. 7, it is possible to determine whether or not the bearing 23 is abnormal at the initial stage of machining. For example, by executing the abnormality determination program 421 at the start of machining, the vibration measurement data 423, the temperature measurement data 424, and the outside air temperature data 425 are acquired in about one minute after a predetermined time has passed since the machining started. (Step S1). Next, these measurement data 423 to 425 are compared with reference data 426 and 427 (step S2), and an abnormality is determined (step S3). If it is determined that no abnormality is found (NO in step S3), machining is continued (step S4). If the occurrence of an abnormality is predicted (YES in step S3), machining is continued while preparing for replacement of the bearing (step S5). In addition, if the degree of abnormality is large, the machining can be stopped.

<6. Features>
According to this embodiment, by measuring the vibration and temperature of the bearing 23 and comparing them with the data when the bearing 23 is normal, it is possible to determine whether the bearing 23 is abnormal. For example, if the degree of abnormality is low, it is possible to predict the abnormality, thereby making preparations for repair or replacement of the bearing 23 . Since it takes time to repair or replace the bearing 23, there is a possibility that processing cannot be performed for a long period of time if repair or the like is suddenly required. Therefore, if the state of the bearing can be predicted as in the present embodiment, preparations for repair or replacement can be made before the bearing 23 breaks down to the point where repair or replacement is necessary, and when a failure occurs, immediate action can be taken. can do. Therefore, the stop time of the apparatus can be shortened.

<7. Variation>
Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications are possible without departing from the gist of the present invention. Note that the following modified examples can be combined as appropriate.

In the above-described embodiment, in the work support unit 3, the work W is held between the headstock 31 and the tailstock 32, but the work W may be supported only by the headstock 31. .

For example, if at least one of the support 21 of the tool support unit 2 and the tool support unit is configured to rotate around the Z-axis, the workpiece can be crowned. Also, in the above embodiment, the tool support unit is moved in the Y-axis direction, but the work support unit may be moved in the Y-axis direction. Also, although the tool housing 22 is rotatable around the Y axis, it may be fixed so that only a predetermined crossing angle can be formed, and the tool housing 22 cannot be rotated.

In the above embodiment, the tool housing 22 is provided with a pair of the vibration measuring sensor 5 and a pair of the temperature measuring sensor 6, but the numbers and positions thereof are not particularly limited. For example, in each bearing 23, three vibration measuring sensors 5 can be provided along the circumferential direction of the bearing 23 at intervals of 120 degrees. Further, in the above embodiment, the vibration and temperature of the outer ring 233 of the bearing 23 are measured, but the measurement position is not limited as long as the vibration and temperature of the bearing 23 can be measured. However, the temperature measurement sensor 6 must be installed at a position where it is not affected by external factors such as cutting oil during machining. Further, it is sufficient that at least vibration can be measured, and the temperature measurement sensor 6 and the outside air temperature sensor 7 can be additionally provided. Moreover, since it is sufficient to measure vibration and temperature, various means such as various sensors can be used.

2 Tool support unit 22 Tool housing 3 Work support unit 4 Control unit 5 Vibration measurement sensor (vibration measurement sensor)
6 temperature measurement sensor (temperature measurement sensor)
7 outside temperature sensor (outside temperature measurement sensor)
W Work

Claims (5)

a work supporting unit that rotatably supports the gear to be machined;
a tool housing that rotatably supports an internal gear-shaped tool meshing with the gear to be machined via a bearing;
vibration measuring means provided in the tool housing for measuring vibration generated in the bearing;
a control unit that acquires vibration measurement data measured by the vibration measurement means and calculates the state of the bearing based on a comparison between the vibration reference data that serves as a reference for vibration and the vibration measurement data;
with
After starting machining of the gear to be machined by the tool, the control unit is configured to continue the machining if a predetermined condition is satisfied in the comparison within a predetermined time. processing equipment.

The control unit is configured to output a determination that an abnormality has occurred in the bearing when the vibration measurement data satisfies a predetermined condition in comparison with the vibration reference data. 2. The gear machining device according to 1. further comprising temperature measuring means provided in the tool housing for measuring the temperature of the bearing;
The control unit is configured to acquire temperature measurement data measured by a temperature measurement means, and to calculate the state of the bearing based on a comparison between temperature reference data, which is a temperature reference, and the temperature measurement data. 3. The gear machining apparatus according to claim 1 or 2, wherein Further comprising an outside air temperature measuring means for measuring the outside air temperature,
The gear machining apparatus according to claim 3, wherein the control section is configured to calculate the state of the bearing by referring to the outside air temperature. The bearing comprises an outer ring, an inner ring, and a plurality of rolling elements arranged between the outer ring and the inner ring,
The internal gear-shaped tool is fixed to the inner ring,
5. The gear machining apparatus according to claim 1, wherein said vibration measuring means is attached to said tool housing so as to be in contact with said outer ring.

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