JP2013141711A - Control method of rotation processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method of a rotation processing device which contributes to energy saving.SOLUTION: Control of a drive mechanism of a motor or the like that rotates a rotation processing tool such as a grindstone is performed by dividing a time zone with no load into an energization stop time which makes the rotation processing tool rotate inertially by stopping energization to the drive mechanism and a start-up time which energizes the drive mechanism so that the rotation processing tool is returned to a steady rotation speed at a time point where processing to a next work starts. This start-up time is shortened in a range where an instantaneous maximum current value that flows through the drive mechanism does not exceed a threshold.

Description

  The present invention relates to a control method for a rotary processing apparatus that processes a workpiece by rotating a rotary processing tool.

  When grinding a gear, for example, by rotating a grinding wheel (rotating tool) with a large rotational inertia, the grinding wheel for gear grinding is driven to rotate by a motor for rotating the grinding wheel, and the gear to be ground is driven by a motor for rotating the gear to be ground. However, at this time, since the grindstone and the gear to be ground must be rotated synchronously while maintaining the rotating phases in alignment with each other, the old grindstone and the gear to be ground have been rotated from the start of rotation. The rotation of the grindstone and the gear to be ground is controlled by relying on a very complicated control circuit so that the grindstone and the gear to be ground can rotate synchronously while having the rotational phases aligned with each other.

  However, in the conventional gear grinding device, not only the control circuit is complicated, but also the grinding wheel with high inertia is stopped from the stop state every time the synchronous rotation is started by matching the rotational phase of the grinding wheel and the gear to be ground. Since it must be started, a great burden is placed on the grindstone support shaft for rotating the grindstone while supporting it.

  Therefore, Patent Document 1 (Japanese Patent Laid-Open No. 58-186523) has been proposed. In this Patent Document 1, while the grindstone is rotated, the rotation phase of the gear to be ground is matched with the rotation phase of the grindstone by a simple control device, and the gear to be ground is synchronously rotated with respect to the grindstone. A gear grinding device that can do this is proposed.

Further, the surface machining of the pulley shaft (fixed side) of the CVT (continuously variable transmission) is also performed by rotating it (steady (rated)) using a grindstone.
CVT has become very popular because it has fewer parts and is lighter than conventional automatic transmissions, and has good fuel efficiency. There are various types of CVT, but the most widely used type is a mechanical metal belt drive type. This metal belt drive type CVT includes a speed change mechanism, a control oil pump, a starting clutch, and a front / rear switching mechanism. The transmission mechanism is composed of a metal V-shaped belt and two pulleys. The metal belt is composed of hundreds of thin steel tip V-shaped elements and two sets of 10 thin steel laminated rings sandwiching the elements from both sides. There are two pulleys, a drive side that transmits the driving force and a driven side that transmits the output to the wheels, and the groove width can be changed by the hydraulic pressure from the control oil pump. The metal belt is put on each pulley, and the element of the metal belt is adapted to fit the inclined angle surface (sheave surface) of the V-shaped groove of the pulley. The side of the V-shaped element is in contact with the pulley, and the steel laminated ring is not in contact with the pulley.

Patent Document 2 (Japanese Patent Laid-Open No. 2004-345057) has been proposed for CVT pulley processing.
In Patent Document 2, in order to omit the setup when grinding the sheave surface and improve the grinding efficiency of the sheave surface, when grinding the sheave surface, the back surface of the disk portion is supported by the disc back surface support mechanism. When supporting and grinding the shaft, the disk back support mechanism is retracted. The grinding jig includes a disk back surface support mechanism that supports the back surface of the disk portion when grinding the sheave surface. The disk back surface support mechanism includes a rotation support means that can rotate together with the disk portion, and the rotation support means. Is moved from the retracted position to the use position, and after use, it is returned to the retracted position by the moving means.

JP 58-186523 A JP 2004-345057 A

When a plurality of workpieces are continuously processed using a rotary processing tool such as a rotating grindstone, the rotational speed of the rotary processing tool during processing must always be constant. For this reason, when the machining interval between the workpieces is short, as shown in FIG. 5, it is efficient to rotate the workpieces regardless of whether they are machining or not.
On the other hand, when the machining interval between the workpieces is long, it is useless to rotate the workpiece at regular intervals when not machining. However, when the processing interval is not extremely long, if a rotating grindstone with a large moment of inertia is stopped or dropped to an extremely low speed, time and a large amount of energy are required until steady rotation is achieved.

The purpose of this application is to eliminate waste from existing processing devices and systems. The grinding / polishing process using a rotary processing device, especially a rotating grindstone that finishes the finished surface, is a continuous machining operation, and the inertia moment of the grindstone is large. And wasted power consumption.

Referring to the following (Table 1), even if the power consumption of each part of the apparatus is analyzed, it is clear that the power consumption of the grinding wheel shaft motor (excluding the liquid temperature control) is extremely large in the drive unit. Furthermore, when the power consumption is measured, since it is always rotating at a constant speed, power is consumed even when there is no load. Therefore, the present invention aims to save power by providing a rotational variation function to the rotary processing tool such as stopping energization when no load is applied or rotating the tool partially.

That is, in the configuration of the present invention, in the control method of the rotary processing apparatus that controls the energization to the drive mechanism that rotates the rotary machining tool that processes the workpiece, the control of the energization to the drive mechanism is performed in an unloaded time zone. The energization stop time for stopping the energization of the drive mechanism and inertial rotation of the rotary machining tool, and the start of energization of the drive mechanism so that the rotary machining tool returns to the steady rotation speed when machining for the next workpiece is started. The rise time was divided into the rise time so that the instantaneous maximum current value flowing through the drive mechanism did not exceed the threshold value.

In this application, in order to protect the processing machine, the maximum instantaneous current value is set, the startup time within the range not exceeding the value and the power consumption is almost minimum is confirmed in advance, and the remaining time is Stop energizing the drive source.
Therefore, in the case of a rotating grindstone, when the drive source power supply is turned off, the rotational speed of the grindstone gradually decreases from that moment, and finally the grindstone stops. When processing continuously, it is necessary to return to the steady rotation before the grindstone completely stops. That is, the grindstone is returned to the steady rotation in a shorter time within a range not exceeding the set maximum instantaneous current value (threshold value). Recently, the number of revolutions of a grinding wheel whose number of revolutions is decreasing is monitored, and an inverter (control device) is used to synchronize the motor and the grinding stone so as to return them to steady rotation.
There is no simple correlation between the steady rotation return time and power consumption of the rotary tool, and the motor stop time and steady rotation where power consumption is almost minimized within a range that does not exceed the maximum instantaneous current value (threshold) set for each device. Determine the combination of return times.

In many cases, the unloaded state having the longest time in the machining process is a process of setting the next unmachined workpiece after the machining of the workpiece is completed. Up to now, this process has been non-operating and no load, and the rotary machining tool has been rotating constantly even though the workpiece has not been machined. If the drive source of the rotary processing tool in this process can be stopped, power consumption can be reduced.
Therefore, as the no-load time zone in the present invention, for example, when a plurality of rotary machining tools are operating in sequence until the machining for the next workpiece starts after the machining for the workpiece is completed. Or a time period during which at least one of the rotary machining tools is inoperative, or a time period in which the line incorporating the rotary machining tool is stopped and then the rotary machining tool is restarted.

In the present invention, the drive system is not limited, and either direct drive or indirect drive may be used, and any known drive type such as belt drive, chain drive, and gear drive may be used for indirect drive.
A specific drive mechanism includes a direct drive or indirect drive electric motor. This electric motor is, for example, a belt drive type, and it is conceivable that the tension and alignment between pulleys that drive the belt are managed.
In the state of constant rotation until now, there is not much problem, but in this application, for indirect drive, especially belt drive, the tension and alignment between pulleys must be measured regularly and managed within an allowable range. I must. This is because there are three patterns: a state where there is no driving force by stopping energization of the drive source of the rotary machining tool with no operation and no load, a steady rotation state without load, and a steady rotation state with load. This is because the change in the state becomes larger than before.

Examples of the workpiece include a cylindrical or disk-shaped workpiece whose outer surface is ground, specifically, a pulley shaft of a continuously variable transmission mechanism.
The pulley shaft of the CVT is forged and subjected to basic processing, followed by heat treatment, and final surface finishing grinding is performed with a circular grindstone. Since the surface of the pulley shaft after heat treatment is hardened, surface processing is difficult unless it is a circular grindstone.

Further, it is preferable to issue a system stop signal when the instantaneous maximum current value exceeds a threshold value.
Failures may occur during operation of the device. For example, belt management cannot be performed unless the device is stopped. Therefore, in the present invention, when the state of the apparatus is monitored on a daily basis, it is easy to monitor continuously, and the current value of the rotary drive apparatus that can be easily implemented is monitored.
As a result, for example, when a problem occurs in the drive system, the electrical system, etc., and an excessive current flows, a system stop signal is issued to the apparatus to stop the apparatus and protect the apparatus and work.

According to the control method of the rotary machining apparatus according to the present invention, wasteful power consumption can be suppressed, and a large current does not flow through the rotary machining apparatus, and the machine and parts are returned to the rated speed without causing damage. And workpiece machining can be performed efficiently.

The top view which shows the example which applied the rotary processing apparatus to which the control method based on this invention was applied to the grinding of the components of CVT (continuously variable transmission). The graph which shows the rotation speed of the rotary processing apparatus which applied the control method which concerns on this invention, the relationship between power consumption, and processing elapsed time The graph which shows the relationship between the energization stop time and start-up time, and rotation speed of the rotary processing apparatus which applied the control method which concerns on this invention The graph which shows the relationship between the restart acceleration time of the rotary processing apparatus to which the control method based on this invention is applied, power consumption, and instantaneous maximum electric current value A graph showing the relationship between the rotational speed and power consumption of a conventional rotary processing apparatus and the elapsed machining time

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the rotary processing apparatus to which the control method according to the present invention is applied has three rotary processing apparatuses 10, 20, and 30 arranged continuously.
The rotary processing device 10 grinds the intermediate portion W1 of the shaft of the member W constituting the CVT pulley, and the rotary processing device 20 grinds the large diameter portion W2 approaching the pulley of the member W constituting the CVT pulley for rotation. The processing apparatus 30 grinds the sheave surfaces of the members constituting the CVT pulley. In the figure, the same grinding process is also applied to the small diameter shaft portion on the right side of the intermediate portion W1.
The workpiece W is ground as a whole by moving the above devices in order.

  Each rotary processing device 10, 20, 30 includes a work table 1, a work table 2 having a core pusher and a main shaft, and a grindstone table 4 having a rotating grindstone 3 moves forward and backward toward the work table 2. The wheel head pulley 4 is provided with a wheel shaft pulley 5, and a belt 9 is stretched between the driving pulley 8 of the driving motor 7 controlled by the inverter 6 and the wheel shaft pulley 5. Thus, the rotational driving force of the driving motor 7 is transmitted to the rotating grindstone 3.

FIG. 2 (a) is a graph showing one processing pattern (the number of rotations of the rotary processing device, power consumption, processing elapsed time) of the rotary processing device, and the specific processing is the sheave surface of the pulley shaft of the CVT or Shaft grinding. Since the processing patterns of the three apparatuses are substantially the same, only one apparatus will be described.

The machining pattern consists of a machining time zone and a no-load time zone, and the no-load time zone refers to the time from when machining to a workpiece is finished until machining is started on a new unmachined workpiece.
In the present invention, the no-load time zone is divided into motor stop time and start-up time as shown in FIG.

The start-up time is the time required to increase the rotation speed of the grindstone whose rotation speed has decreased to the steady rotation at the start of machining of an unmachined workpiece. As shown in FIG. 4, if this time is shortened, the motor stops. Longer time and less power consumption. However, if the start-up time is shortened, the instantaneous maximum current value suddenly increases, the force acting on the component parts of the apparatus such as the belt and the work changes, and the life of the component parts may be shortened and the work may be damaged.

Therefore, a threshold is set in advance as an allowable instantaneous maximum current value, and the start-up time is shortened as much as possible within a range not exceeding this threshold. This optimum start-up time varies depending on the type and shape of the workpiece, the type of rotary processing apparatus, the steady rotational speed, and the like.
As an example of grinding the pulley shaft, the threshold of the instantaneous maximum current value is 90 amperes / second, and when the no-load time zone is 29 seconds, the startup time is preferably 10 to 12 seconds. .

In the above embodiment, as an example of the no-load time zone, the period from the end of the workpiece processing to the start of the processing of the next unmachined workpiece is mentioned. While one machine is dressed, the remaining two machines are in a no-load state because the machining of the workpiece is stopped. In this case, the pattern shown in FIG.

That is, when the rotating grindstone becomes wet, the grinding ability decreases, and therefore it is necessary to always keep the dried state. If the rotational speed of the rotating grindstones of the remaining two devices that are not dressed falls below a certain value, moisture may be adsorbed and the grinding ability may be reduced.
Therefore, the remaining two units are drained while maintaining a certain value (2000 rpm) or more.

The operation | work which reproduces the grindstone surface with a dress is performed frequently. Therefore, a combination of FIGS. 2A and 2B can be considered as the processing pattern.

Further, the pattern in which the rotary machining apparatus is in an unloaded state is a case where the production line is stopped for some reason. In this case, since it is not known when the operation is resumed, the pattern shown in FIG. 2B is used until the set time. However, when the set time has passed, the energization of the motor is stopped.

The control method of the rotary machining apparatus according to the present invention is used as a control method of a rotary machining apparatus that grinds the sheave surface of a pulley shaft of CVT, for example.

10, 20, 30 ... rotational processing apparatus,
DESCRIPTION OF SYMBOLS 1 ... Processing table, 2 ... Work table, 3 ... Rotary grindstone, 4 ... Grinding wheel base, 5 ... Grinding wheel shaft pulley, 6 ... Inverter, 7 ... Drive motor, 8 ... Drive pulley, 9 ... Belt,
W ... Work.

Claims (7)

In a control method of a rotary processing apparatus that controls energization to a drive mechanism that rotates a rotary processing tool that processes a workpiece,
The energization of the drive mechanism is controlled in the no-load time period, the energization stop time for stopping the energization of the drive mechanism and inertial rotation of the rotary machining tool, and the rotation at the time of starting machining for the next workpiece. The processing tool is divided into start-up times for energizing the drive mechanism so as to return to the steady rotational speed, and the start-up time is shortened so that the instantaneous maximum current value flowing through the drive mechanism does not exceed a threshold value. A control method of a rotary processing apparatus. In the control method of the rotary machining apparatus according to claim 1, the no-load time zone is a period after the machining for a workpiece is completed until machining for the next workpiece is started.
When multiple rotary tools are operating in sequence, at least one of them is inactive, or until the line where the rotary tools are installed stops and then the rotary tools are restarted A control method for a rotary machining apparatus, wherein   2. The method of controlling a rotary machining apparatus according to claim 1, wherein the drive mechanism is a direct drive or indirect drive electric motor.   4. The method of controlling a rotary machining apparatus according to claim 3, wherein the indirect drive electric motor is a belt drive type, and tension and alignment between pulleys for driving the belt are managed. Control method.   2. The method of controlling a rotary machining apparatus according to claim 1, wherein the workpiece is a cylindrical and / or disk workpiece whose outer surface is ground.   6. The method of controlling a rotary machining apparatus according to claim 5, wherein the workpiece is a pulley shaft of a continuously variable transmission mechanism.   2. The method of controlling a rotary machining apparatus according to claim 1, wherein a system stop signal is generated when the instantaneous maximum current value exceeds a threshold value.

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