KR20000063579A - Precision Dip Coater - Google Patents

Abstract

PURPOSE: A precise dip coater is provided which does not vibrate in a low speed range and can control a velocity precisely so can make homogeneous coating film. CONSTITUTION: The dip coater includes a reduction gear(5) mounted between an AC servo motor(7) and a ball screw(2), wherein the reduction rate of the reduction gear(5) ranges from 1/1 to 1/100, the ball screw(2) having a ball nut(12), a ball rail guide(1) having one or two blocks(11), a supporting plate(6) having a plurality of bolt's holes for transferring an object for coating, wherein the supporting plate(6) can be fixed on the blocks(11) in all directions, an electronic brake(10) mounted on the upper ball screw(2). The object for coating is transferred at a speed range of 0-1000 mm/sec and speed control accuracy is 0.001 mm/sec. The dip coater is controlled by a PID control method using pulse signal of a rotary encoder located in the AC servo motor(7).

Description

Precision Dip Coater {Precision Dip Coater}

The present invention relates to a precision coating apparatus capable of coating a surface of an object with a film having a desired thickness by dipping a solid object to be coated in various solutions and lifting the object from a solution at a specified uniform speed.

The present invention relates to a precision deep coating apparatus composed of a ball screw, a ball screw support bearing, a precision support, a speed reducer, an AC servomotor, a position controller board and a speed control computer and software used in a conventional machine tool. The motor control unit for constructing these parts and precisely conveying them for coating is included in the mechanical engineering field of engineering, and the part for coating a target object using a dip coating device is chemical engineering, industrial engineering and material engineering. Belongs to the field.

In our country, there are currently no dip coaters used for similar purposes, and many of them are used in automation business using AC servomotors and ball screws for horizontal conveyance not in the purpose of coaters but in similar shapes. However, most of the conveying devices are horizontal conveying devices, and the speed control method is PLC control method, which makes precise and stable film thickness control possible, especially in the low speed area, without precise and stable control without motor vibration. It cannot be used for the required dip coater.

The present invention is characterized in that the vertical feed for the purpose of the coater is added, and a reduction gear is added between the ball screw and the AC servomotor in order to enable the vertical feed without vibration in the low speed region, The present invention relates to a coating apparatus designed to make a homogeneous coating film without vibrating in the region and enabling precise speed control. The motor control method of the deep coater according to the present invention adopts a closed loop PID control method using a pulse signal of a rotary encoder embedded in the motor and is controlled by a personal computer, and the number of generated pulses of the rotary encoder per rotation of the AC servomotor is about 130,000. By using more than tens to hundreds of times more pulse signals for control than thousands of conventional pulses, more precise and low vibration control is possible in the low speed region.

1. The present invention is a device for vertically conveying an object to be coated for use for the purpose of a dip coater in which a solid object is immersed in a solution and pulled out at a predetermined speed. Particularly, in the low speed region, precise speed control is possible without vibration. It relates to a dip coating apparatus capable of making a homogeneous coating film.

2. The speed reducer is added between the ball screw and the AC servomotor so that the multi-step speed can be changed precisely without vibration in the low speed region, which is the object of 1 above.

3. The motor control method of the dip coater according to the present invention adopts a closed loop PID control method using a pulse signal of a rotary encoder embedded in the motor and is controlled by a control computer, and the number of pulses generated by the rotary encoder per rotation of the AC servomotor is controlled. By using about 130,000 pulse signals of several tens to hundreds of times more than thousands of pulses of the conventional servomotor, it is possible to control more precisely and low vibration in low speed area, so that coating of uniform film thickness is possible.

1 is a trigonometric drawing of a precision dip coater

2 is a schematic diagram of a feed speed controller of a precision dip coater;

Explanation of symbols for main parts of the drawings

(1) ball rail guide (2) ball screw

(3) ball screw bottom bearing (4) ball screw top bearing

(5) reduction gears (6) coating object supports

(7) AC servo motor (8) Lower position sensor

(9) Up position sensor (10) Electronic brake

(11) Block of ball rail guide (12) Ball screw nut

1 shows a trigonometric diagram of a precision dip coater of the present invention. The dip coater includes (1) ball rail guide, (2) ball screw, (3) ball screw bottom bearing, (4) ball screw top bearing, (5) reduction gear, (6) coating object support, (7) AC servo It consists of a motor, (8) lower position sensor and (9) upper position sensor, (10) electromagnetic brake, (11) ball rail guide block, and (12) ball screw nut.

The characteristic of the device of the present invention is that the torque of the motor is small in the low speed region, and the vibration is easy to occur, so that the servo motor is kept at a low speed while the servomotor is operated at a slightly higher speed to maintain the speed of feeding from the ball screw 2 at low speed. The reducer 5 is installed between the motor 7 and the ball screw 2. The reduction ratio of the reduction gear 5 can be selected according to a desired speed in the range of 1/1-1/100, and the reduction gear type is helical gear type, planetary gear type, spiral bevel gear type, hypoid gear type, Among the precision ball type, worm gear type, etc., the one with small backlash is used. When carrying out the coating of the dip coating apparatus of the present invention, the conveying speed range of the coating object is 0-1000 mm / sec, and the speed control precision has a characteristic of precision of 0.001 mm / sec.

The threaded lead of the ball screw 2 can select the lead according to an appropriate predetermined speed in the range of 1-30 mm / rotation. The outer diameter of the screw shaft of the ball screw 2 can be selected in the range of 4-100 mm, the size of which can be selected and designed according to the weight and speed to be transferred. The ball screw nut can be of the preload type for large loads and the non-preload type for normal types. The ball screw 2 is supported by the upper support bearing 4 and the lower support bearing 4.

The support 6 of the coating object is first fixed on the ball screw nut 12 of the ball screw 2, and then fixed to the block 11 of the ball rail guide 1 in order to reduce the load of the coating object hanging thereon. I install it. The weight of the coating object that can be suspended on the support is determined by the specifications of the ball screw 2 and the servomotor 7, and the weight that can be transported by reinforcing with the ball rail guide 1 can be further increased.

The specification of the ball rail guide 1 can be selected by designing according to the weight of the object to be conveyed, the conveying speed. The shape of the block 11 of the ball rail guide 1 may use one block type or two block types. The mounting method of the object support 6 in the block of the ball rail guide 1 can be installed on the basis of the direction as shown in FIG. 1, and the installation direction of the block gives an appropriate angle from the basic direction so that the object support 6 can be accurately positioned. It can also be mounted in any direction that can be supported. The support 6 is characterized in that it has a plurality of holes or screw holes to make and attach a suitable auxiliary fixing tool according to the shape or weight of the object to be coated.

The motor for power used in the present invention is based on a servo motor, and in addition, a step motor, a DC motor, an AC motor, and the like can be used.

The coating process of the dip coater involves changing the feed rate during the coating or waiting for a long time at rest. In this way, if the stop state for a long time during the coating is performed under the control of the coater, heat is generated in the servomotor 7 and causes a failure of the motor. Therefore, the present invention adopts a method of fixing a ball screw (2) shaft by installing a separate electromagnetic brake 10 on the top of the ball screw (2) for the process of stopping the feed device for a long time.

In the present invention, the position control of the ball screw nut 12 of the ball screw 2 is precisely performed by the control unit, but the lower position sensor 8 and the lower limit position and the upper limit position of the ball screw nut 12 for emergency use. Fixing the upper position sensor (9) is characterized in that the ball screw nut (12) is equipped with a safety device that necessarily stops when reaching the lower and upper limit position.

The position of the servomotor and the speed reducer for rotating the ball screw 2 of the main body is based on the lower part as shown in FIG. 1, and in some cases, may be located at the upper part, in this case, the position of the electromagnetic brake 10. Comes to the bottom.

Figure 2 shows a schematic diagram of the feed rate control unit of the precision dip coater. The control unit is composed of (2a) servo motor amplifier, (2b) data input board and output board, (3c) operation control board, and (2b) control computer.

The servomotor 7 and the servomotor amplifier 2a in the main body of the present invention are connected, and the servomotor amplifier is connected with the position control board 2c, so as to position control signals from the software of the control computer 2b. The signal sent through the board 2c and calculated here controls the motor through the servomotor amplifier 2a to control the rotational speed of the ball screw 2 and the position of the ball screw nut 12. The signal from the up and down position sensor enters the input board and the output board 2b of data and is used for computation of the computer.

The control method of the present invention is controlled by adopting a closed loop PID control method that performs feedback control by using pulse signals of a rotary encoder included in an AC servo motor, and all of these controls are input boards of data embedded in a computer. Through the output board 2b and the motion control board 2c, it is controlled by the window program of the control computer 2d, so it is more precise and stable without vibrating in speed change or various pattern coating conditions, especially acceleration, deceleration and low speed region. It is configured to enable stable transport. The precision dip coating apparatus of the present invention is configured to linearly accelerate and decelerate the feed rate control during a feed stroke, and instructs a multi-step speed change process such as maintaining a constant speed for a predetermined time with one program. It consists of software that can do it.

According to the present invention, the present dip coating apparatus can localize expensive precision machinery that is dependent on imports by developing a device capable of producing a homogeneous coating film without vibration and precise speed control in a low speed region. It is effective and can make precision coating film, which will greatly contribute to product development in industrial chemistry, chemical industry and material industry.

The motor control method of the deep coater of the present invention adopts a closed loop PID control method using many pulse signals of a rotary encoder embedded in a motor, and is controlled by a computer. It is possible to apply to factory automation technology by possible technique.

It is possible to localize the precision dip coating device to raise the mechanical technology of this field to the next level, and it is possible to develop environmentally friendly materials uniformly coated on various objects by using the present invention, which will greatly contribute to national industrial development. It is expected.

Claims (4)

In order to reduce the vibration in the low speed range and to precisely cope with the multi-stage speed change, a speed reducer in the range of 1/1-1/100 is installed between the shaft drive motor and the ball screw, and the feed speed is 0-1000 mm / sec, The precision of the feed speed is 0.001 mm / sec. The threaded lead of the screw, which is the main part of the conveying part, is in the range of 1-30 mm / rotation, the outer diameter of the screw shaft of the ball screw is in the range of 4-100 mm, the ball screw nut is preloaded or non-preloaded, and the transfer weight The ball rail guides with one or two blocks can be fixed in any direction so that they can be mounted in any direction, and the support of the coated object can be equipped with appropriate auxiliary tools according to the shape or weight of the coated object. Deep coating device, characterized in that it has a plurality of holes or screw holes. Deep coating device adopting the method of fixing the feed shaft by holding the ball screw by installing an electromagnetic brake on the top of the ball screw in order to prevent the heat generation or failure of the motor in advance in the process that the feed shaft is stopped for a long time. By controlling the PID control method of the closed loop which performs feedback control using the pulse signal of the rotary encoder built in the AC servo motor by computer, it does not vibrate in speed change or various pattern coating conditions, especially acceleration, deceleration and low speed area. Deep coating device with software for precise and stable speed control.