JPH02224838A - Motor-driven type form rolling device - Google Patents

Abstract

PURPOSE:To eliminate the need of a mechanical synchronizing mechanism and to prevent the generation of an error caused by looseness by outputting a speed command pulse to a servomotor so as to synchronize a speed of a slider by a signal from a position detector of the servomotor. CONSTITUTION:A speed command pulse is outputted from a controller 31 to each control system of AC servomotors 16, 16', the motors 16, 16' rotate, ball screws 17, 17' are brought to forward rotation, sliders 18, 18' approach, a stock 23 is pressed from both sides by form rolling dies 19, 19', and form rolling is executed. Positions of the sliders 18, 18' are detected indirectly by position detectors 38, 38', and brought to feedback to the controller 31. The controller 31 compares each signal, and controls the speed command pulse so that both the sliders 18, 18' are synchronized, therefore, both of them are synchronized completely. It is unnecessary to interlock them mechanically, and the generation of an error can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rolling device for forming screw gears and the like for power transmission of mechanical parts, and particularly to a rolling device using a motor as a drive source.

[Conventional technology]

In the rolling device No.-m, a pair of columns are provided on the frame, and a slider to which a rolling die is attached is slidably held in opposing slide holders of each column. A hydraulic cylinder is arranged in the upper part of the frame, and each slider is moved up and down along the slide holder from the output shaft of the hydraulic cylinder via a rank and pinion mechanism.

However, in the above-mentioned rolling device, since the input from the pinion is outputted via the rack and pinion, a large input is required, and a high-output hydraulic cylinder must be used. Therefore, in a high-input system using a hydraulic cylinder, the hydraulic pump becomes large and the pressure at the joints of the hydraulic piping is high, so even if a seal is provided, there are many problems such as oil leaks. As the machines became larger and more robust, they produced more noise and vibration, creating problems in the working environment.

Therefore, the present applicant has previously proposed a rolling device that can be operated with a small input and does not cause leakage of working fluid or deterioration of the working environment (Japanese Patent Application Laid-Open No. 63-1999-1).
In the rolling device disclosed in Publication No. 235036), a slider is raised and lowered by a feed screw connected to an electric servo motor. As shown in FIG. 5, each slider 2 to which a rolling die 1 is attached is provided with a rack 3, and the racks 3 are synchronously linked to each other via a pinion 4.

In the rolling device configured in this way, since the sliders 2 of the mutual rolling dies 1 are linked by the rack 3 and the pinion 4, only one slider 2 is fast (does not move and is stable). Torque can be transmitted through synchronous operation.

[Problems to be Solved by the Invention] However, the rolling device shown in FIG. 5 also had problems to be solved. That is, the synchronization mechanism using a rack and a pinion has a problem in that it is difficult to maintain high rolling accuracy due to backlash and cumulative pitch error caused by the processing accuracy of the gear. Furthermore, since the sliders are mechanically synchronized, the mechanism is complicated and the cost of the device is high.

The present invention has focused on the above problem and aims to provide a rolling device that can synchronize the moving speed of each slider without using a mechanical synchronization mechanism such as a rack and a pinion.

[Means to solve the problem]

An electrically driven rolling device according to the present invention that meets this purpose includes slide holders provided in a pair of columns of a frame, each slide holder movably holding a slider to which a rolling die is attached; In an electrically driven rolling device in which a slider is raised and lowered by a feed screw connected to an electric servo motor, each electric servo motor is provided with a feed bank from a position detector connected to each electric servo motor. Each electric servo motor is connected to a controller that outputs speed command pulses so that the speeds of both sliders are synchronized by comparing signals and based on the results of the calculation.

[Effect]

In the electrically driven rolling device configured in this way,
The position of each slider is fed back to the controller by a position detector, and the difference is compared and calculated in the controller. Then, the controller adjusts the speed command pulses to be output to each electric servo motor based on the results of the comparison calculation. In other words, during rolling, the positions of both sliders are reliably grasped by each position detector, and if the moving speeds are likely to be out of synchronization, the speeds of both sliders are controlled by correcting the speed command pulses. This enables highly accurate synchronization.

Therefore, unlike the conventional mechanical synchronization mechanism, there is no need for it, and the cost of the VI device can be reduced. Additionally, cumulative pinch errors caused by backlash due to gear machining accuracy are eliminated, and rolling accuracy is improved.

〔Example〕

Preferred embodiments of the electrically driven rolling device according to the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention, and in particular, the invention is applied to rolling of a worm gear. In FIG. 0, numeral 11 indicates a rolling device.
A frame 13 provided on the base is provided with a pair of columns 14 extending upward. Slide holders 15, 15' are provided on opposing inner surfaces of each column 14, facing each other.

At the top of the frame 13, two electric servo motors (
AC servo motor) 16.16' is installed.

Each AC servo motor 16, 16' includes a speed detector and a position detector, which will be described later. A ball screw 17.17' serving as a feed screw extending in the vertical direction is connected to the output shaft of each electric servo motor 16.16'. Each slide holder 15.15' has a slider 1
8.18' is held slidably in the vertical direction. One ball screw 17 is screwed into a slider 18, and the slider 17 moves up and down along the slide holder 15 by the rotation of the ball screw 17. The other slider 18' is similarly constructed. Each slider 18
．． A rolling die 19 for rolling a cylindrical workpiece (raw material) 23 is provided at 18'.

A predetermined interval is set between one rolling die 17 and the other rolling die 17', and both rolling dies 19.1
A spindle center 21 is located on one side of 9', and a mandrel center 22 is located on the other side. The end face of the material 23 to be rolled is connected to the spindle center 21 and the mandrel center 2.
2 and is rotatably pressed and held.

FIG. 3 shows an AC servo motor 16, a ball screw 17,
The connection relationship with the slider 18 is shown. When the AC servo motor 16 is rotated in the direction shown by arrow A in the figure,
The rolling die 19 attached to the slider 8 via the ball screw 17 moves downward, and conversely, when the AC servo motor 16 is rotated in the direction shown by arrow B, the rolling die 19 moves upward. It is supposed to be done. The connection relationship between the other AC servo motor 16', ball screw 17', and slider 18' is also similar to this.

FIG. 4 shows a control block diagram of the AC servo motor 16, in which numeral 31 indicates a controller (controller module), and the controller 31 has a function of performing comparison calculations based on external signals. and
It has a function of outputting a speed command pulse according to the result of comparison calculation. The controller 31 controls both the one AC servo motor 16 and the other AC servo motor 16', and controls the other AC servo motor 1.
Since the control configuration of AC servo motor 6' is similar to that of one AC servo motor 16, only the control configuration of one AC servo motor 16 will be described.

The controller 31 is connected to a deviation counter 32, and speed command pulses from the controller 31 are input to the deviation counter 32.

The deviation counter 32 is connected to a digital-to-analog converter 33, and subtracts the number of input pulses from the number of pulses fed back from a position detector, which will be described later. - The digital-to-analog converter 33, which is designed to command the analog converter 33, commands the speed by placing input pulses in voltage.

The digital-to-analog converter 33 is connected to a speed amplifier 34. The speed amplifier 34 further replaces the speed command, which has been replaced with voltage, with current, and uses it as a current command. The speed amplifier 34 is connected to a current limiter 35, and the ifL limiter 35 issues a command to limit current. This is to prevent the load on the two AC servo motors 16, 16' from being larger than expected and to prevent abnormal current from flowing.

The current limiter 35 is connected to a current amplifier 36,
The current command of the current limiter 35 is amplified by this current amplifier 3G. The current amplifier 36 is connected to a current transformer 37, the amplified current command is detected by the current transformer 37, and this detected value is fed back to the input side of the current amplifier 36. This current transformer 37 is connected to the AC servo motor 16.

The AC servo motor 16 has a speed detection i? which is mechanically connected to the output shaft of the motor. 1i38 and a position detector 39 are built in. The speed detector 38 detects the rotational speed of the output shaft,
In other words, the moving speed of the slider 18 is indirectly detected, and the position detector 39 detects the rotation amount (
The amount of rotation of the motor and the amount of rotation of the ball screw are the same),
That is, the position of the slider 18 is indirectly detected. The speed detector 38 is connected to the speed amplifier 34 and sends the moving speed signal of the slider 18 to the speed amplifier 340.
The 0 position detector 34, which is designed to feed back to the input side, is connected to the controller 31 and the deviation counter 32.
The position signal of the slider 18 is fed back to the input side of the controller 31 and the deviation counter 32.

Similarly, the configuration for controlling the other AC servo motor 16' is similar to that described above, including a deviation counter 32', a digital-to-analog converter 33', a speed amplifier 34', and a current limiter 35'.
', a current amplifier 36', a current transformer 37', a speed detector 38', and a position detector 39'.

As described above, the controller 31 includes a position detector 39 for one motor and a position detector 39 for the other motor.
′ is input. The controller 31 compares and calculates the input signals, and based on this calculation result, controls each AC servo motor 16, 16' so that both sliders 18, 18' reach the same position.
Adjust the speed command pulse output to.

Next, the operation of the electrically driven rolling device described above will be explained.

First, a cylindrical material 23 is rotatably held by the spindle center 21 and the six-axis center 22. When support of the material 23 is confirmed, a speed boat command pulse is output from the controller 31 to each control system of both AC servo motors 16, 16', and each AC servo motor 161, 16' is rotationally driven. When each AC servo motor 16.16' rotates,
Each ball screw 17, 17' rotates forward, and each slider 18
．． 18' are close to each other along the corresponding slide holder 15.15', and the blank 23 is pressed from both sides by a rolling die 19.19' mounted on each slide 18.18'. Therefore, the material 23 is rolled through the rolling die 19.
19', the blank 23 is formed into a worm gear.

In this case, the position of each slider 18 , 18 ′ is detected indirectly by a position detector 38 , 38 ′, and this detected value is fed back to the controller 31 .

The controller 31 compares and calculates each feedback signal and controls the speed command pulse so that both sliders 18.18' are synchronized.
The movement speeds of ' are almost perfectly synchronized.

In this way, with the configuration in which synchronization is performed using electrical signals, the slider speed control processing can be performed in a very short time, and the synchronization of the left and right sliders can be maintained with high precision. Therefore, there is no need to mechanically interlock the left and right sliders 18, 18', and the mechanism can be simplified.

〔Effect of the invention〕

As explained above, when using the electrically driven rolling device according to the present invention, the feedback signals from the position detectors are compared and calculated for each electric servo motor, and both sliders are synchronized based on the calculation results. Since a controller that outputs speed command pulses is connected to each motor, the moving speeds of each slider can be almost completely synchronized.

Therefore, unlike conventional devices, mechanical synchronization mechanisms such as ranks and binions are not required, and the cost of the device can be reduced. Further, it is possible to eliminate the occurrence of cumulative pitch errors due to play caused by the processing accuracy of the gear, and it is possible to improve the rolling accuracy.

[Brief explanation of the drawing]

FIG. 1 is a front view of an electrically driven rolling device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line nn in FIG. 1, and FIG.
FIG. 4 is a control block diagram of the device shown in FIG. 1, and FIG. 5 is a cross-sectional view of the main parts of a conventional electrically driven rolling device. 13...Frame 15.15'...Slide holder 16.16'
......Electric servo motor (AC servo motor) 17.17'...Feed screw (ball screw) 18
．． 18'...Slider 19.19'...Rolling die 31...Controller 39.39'...Position detection 8 Patent applicant Toyota Motor Corporation Co., Ltd. Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] 1. Slide holders are provided on each of the pair of columns of the frame, and each slide holder movably holds a slider to which a rolling die is attached, and each slider is raised and lowered by a feed screw connected to an electric servo motor. In the electrically driven rolling device, feedback signals from position detectors connected to each of the electric servo motors are compared and calculated, and based on the calculation results, both sliders are moved. An electrically driven rolling device characterized in that a controller that outputs a speed command pulse is connected to each electric servo motor so that the speeds of the two motors are synchronized.