JPH04141262A - Automatic coating device - Google Patents

Abstract

PURPOSE:To perform coating with a uniform thickness by providing non-contact sensors which detect the position of any region moving back and forth in synchronization with a coating device, position/speed conversion device of a crank drive motor and a crank drive motor control device. CONSTITUTION:Non-contact sensors S are arranged on a rocking orbit for a parallel link 3A, and data on the position of moving coating devices 2A, 2B is output. For example, a motor 6 is driven at high rotation speed from a left reversing position P0 to a speed acceleration end position P1 and thereby the coating devices 2A, 2B are driven at accelerated speed. If the coating devices 2A, 2B reach the speed acceleration end position P1, a paint valve 12 opens to initiate coating. Next, rotation speed of the motor 6 slows down upto a position where parallel links 3A, 3B become vertical during a period when the devices are reaching a speed reduction start position P2 and then ascend at this position P6 where the rotating speed has dropped. If the devices arrive at the speed reduction start position P2, a paint valve 12 is closed and the rotating speed is maintained at high level until the devices arrive at a right reversing position P7 and a speed acceleration end position P3. When the coating devices move at uniform speed, paint is supplied at constant flow to perform painting.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a method for reciprocating a coating machine in a direction perpendicular to the conveyance direction of the object to be coated along the painting surface of the object to be coated, which is being conveyed at a predetermined speed. The present invention relates to a coating device that moves, and particularly to a coating device that uses a crank mechanism to reciprocate the coating machine.

[Conventional technology]

Conventional painting equipment that paints the upper surface of a car body that is transported at a predetermined speed by a conveyor uses an elevating frame that moves up and down according to the shape of the car body and is arranged horizontally in the left-right direction perpendicular to the direction in which the car body is transported. Generally, a coating machine is attached to a slider that is movable along the elevating frame, and the slider is moved back and forth by a drive chain that runs parallel between a pair of left and right sprockets.

However, if the lift frame that moves up and down above the car body is equipped with a slider and a chain sprocket mechanism that makes the slider reciprocate, the overall size of the lift frame becomes large, so it must be introduced from the ceiling of the painting room. There was a risk that the paint mist sprayed from the paint sprayer could fly up by blocking or disturbing the flow of clean air sucked into the floor.

Furthermore, there is a risk that droplets of lubricating oil adhering to the drive chain running between the sprockets may fall onto the painted surface of the automobile body, causing paint film defects.

For this reason, the applicant proposed a slider installed on the lifting frame instead of the chain sprocket mechanism. Slider-crank machine connected to the crank installed in 1IIIJ with a loft for reciprocating motion - Bridge (Japanese Patent Application Laid-Open No. 1986-
232268), or by eliminating the slider from the lifting frame and suspending the lifting frame to which the paint sprayer is directly attached horizontally from the left and right links.
A crank mechanism (Japanese Unexamined Patent Application Publication No. 1988-88072) that uses a crank connected to one link via a loft to move the entire elevating frame in a pendulum manner, or a paint machine suspended from the elevating frame by a link is connected to that link. A crank mechanism (Japanese Utility Model Publication No. 1983-56862) is adopted in which a pendulum movement is caused by a crank connected via a rod.

By the way, both the chain sprocket mechanism and the crank mechanism cause the paint sprayer to move back and forth to decelerate as it approaches the reversal position of the forward and return trips, momentarily stop at the reversal position, and then accelerate. There is a problem in that uniform coating cannot be achieved even if the amount of paint discharged is constant.

For this reason, the applicant temporarily reduces the amount of paint discharged from the paint sprayer from the time the paint sprayer approaches the reversal position and starts decelerating until it passes the reversal position and finishes accelerating. 2-174971), or the discharge of paint is completely stopped so that painting is not performed near the reversal position.

[Problem to be solved by the invention]

However, when the paint sprayer is reciprocated by a crank mechanism, unlike in the case of a chain sprocket mechanism, the speed of the paint sprayer changes continuously even on the way to the reversal position. There remained the problem that a uniform coating thickness could not be obtained by simply reducing the discharge amount or stopping the paint discharge.

In order to make the coating thickness uniform, it is possible to adjust the amount of paint discharged by varying the rotation speed of the pump that sends the paint to the paint sprayer, but if the amount of paint discharged increases or decreases during the painting process, the coating pattern may change. This is not desirable when performing high-quality painting.

Therefore, the present invention aims to make the speed of the paint sprayer, which is reciprocated by a crank mechanism, constant until it reaches the reversal position, thereby making it possible to apply high-quality paint with an extremely uniform coating thickness. l! The topic is

[Means to solve the problem]

In order to solve this problem, an automatic painting device according to the present invention has a plurality of non-contact units installed at arbitrary locations that reciprocate in synchronization with a paint machine that is reciprocated by a crank mechanism to detect the position of an object to be detected. A contact sensor is arranged along a trajectory along which the object to be detected reciprocates, and a rotation of a crank drive motor corresponding to the position of the object to be detected is arranged in order to equalize the reciprocating movement of the paint sprayer. It is characterized by comprising a position-speed conversion means for setting a speed, and a control means for varying the rotational speed of the crank drive motor based on speed data corresponding to the position of the detected object obtained by the conversion means. shall be.

[Effect]

According to the present invention, a coating machine is reciprocated by a crank mechanism, and a detected object provided at an arbitrary part reciprocating in synchronization with the coating machine is detected by a plurality of non-contact sensors, and the object to be detected is detected by a plurality of non-contact sensors. The position of the machine is detected.

Then, the rotational speed of the crank drive motor is continuously and variably controlled based on speed data corresponding to the position of the sprayer, so that the reciprocating motion of the sprayer is equalized.

C Embodiment] The present invention will be specifically described below based on an embodiment shown in the drawings.

Fig. 1 is a flow sheet showing an example of an automatic painting device according to the present invention, and Figs. 2 (a) to (d) respectively show the position of the coating machine, the rotational speed of the motor, the moving speed of the coating machine, and the on/off of the paint valve. It is a graph showing the state.

In the figure, reference numeral 1 denotes an elevating frame that is disposed horizontally orthogonally to the conveyance path of the object W to be coated and is raised and lowered according to the shape and conveyance speed of the object W. A plurality of bell-shaped electrostatic coating machines 2A and 2B are provided at predetermined intervals.

The lifting frame 1 also includes a pair of parallel links 3A whose both ends are pendulum-moved in a direction perpendicular to the conveyance path of the workpiece W.
, 3B, and is suspended horizontally.

One parallel link 3B is connected to a crank mechanism C consisting of a crank 4 rotated in a fixed direction and a connecting rod 5, and the crank 4 is configured to be rotationally driven by a motor 6 via a speed reducer 7. There is.

A detected object H is provided at a predetermined position of the other parallel link 3A, and the detected object H is
A plurality of non-contact sensors S are arranged at predetermined intervals on a trajectory drawn as the robot swings.

For example, if we consider a case where the parallel link 3A swings with an amplitude of 30° and a magnetic sensor M using a Hall element is used as the non-contact sensor S, the detected object H is 10°.
An alnico magnet (G) of about 0.00 Gauss is used and is attached to a predetermined position of the parallel link 3A with an adhesive or the like.

Fifteen magnetic sensors M- are arranged at intervals of 2 degrees apart from the magnet (G) by about several millimeters. In this case, every time the parallel link 3A moves 2 degrees, an electric signal indicating the position will be generated.

8 is a control device that controls the rotational speed of the motor 6 based on the electric signal output from the magnetic sensor 7M, and controls the coating machine 2A based on the electric signal output from the magnetic sensor M; 2B position data and outputs speed data from a position-speed conversion table in which the rotational speed of the motor 6 corresponding to the position data is stored in advance; and an inverter 10 that controls the rotational speed of the motor 6 to be increased or decreased.

The position-speed conversion table of the position-speed conversion means 9 shows, for example, the acceleration end position P1 of the paint sprayers 2A, 2B that are reciprocated at one end of their stroke.
Deceleration start position P2 at the other end from P3. So that the speed until reaching P4 is constant (ji! 2 (a),
(c)), Painter 2A.

The rotational speed of the motor 6 is set in advance according to the electric signal of the magnetic sensor M indicating the position of the motor 6, and the deceleration start position P2. The rotational speed of the motor 6 is set high from P4 until the direction of movement is reversed and the acceleration end position Pi reaches P3 (FIG. 2(b)).

The position-speed conversion means 9 includes each coating machine 2A.

A valve controller 13 that controls opening and closing of a paint valve 12 installed in a paint supply pipe 11 connected to the paint supply pipe 2B is connected, and the paint sprayers 2A and 2B move from acceleration end positions PL and P3 at one end to the other end. Deceleration start position P2. P4
The paint is supplied only until the end (the second
Figure (d)).

The above is an example of the configuration of the present invention, and its operation will be explained next.

When the automatic coating device is started, position data indicating the positions of the coating machines 2A and 2B is output in accordance with the signals output from each magnetic sensor M, and the rotational speed of the motor 6 is variably controlled in accordance with each position. Ru.

For example, until the paint sprayers 2A and 2B reach the acceleration end position P1 from the left-side reversal position PO, the motor 6 is operated at a high rotational speed.
is driven, and the moving speed of the paint sprayers 2A and 2B is gradually accelerated from 0, and at this time the paint valve 12 is closed.

Next, when the coating machines 2A and 2B reach the acceleration end position P1, the valve controller 13 outputs a control signal to open the paint valve 12, and painting starts.

Then, until the coating machines 2A, 2B reach the deceleration start position P2 from the acceleration end position P1,
The rotational speed of the motor 6 is gradually lowered to a position P6 where B becomes vertical, and the rotational speed is gradually increased from this position P6 to a deceleration start position P2, and from the acceleration end position P1 to the deceleration start position P2. The paint machines 2A and 2B move to the right at a constant speed, and paint is supplied at a constant flow rate to perform painting, resulting in high-quality painting with a uniform coating thickness without changing the painting pattern. becomes possible.

Next, when the coating machines 2A, 2B reach the deceleration start position P2, the valve controller 13 outputs a control signal to close the paint valve 12, and the supply of paint is stopped.

The rotational speed of the motor 6 is maintained high until the paint sprayers 2A, 2B reach the right side reversal position P7 from the deceleration start position P2, the direction of travel is reversed to the left, and reach the acceleration end position P3. .

Then, from the right side reversal position P7, the acceleration end position P3
- Position P8 where the parallel links 3A, 3B become vertical - Deceleration start position P4 - Left side reversal position P5 (=PO) The rotational speed is controlled, the paint valve 12 is opened from the acceleration end position P3 to the deceleration start position P4, and when the paint sprayers 2A and 2B return to the left, the paint is applied only while moving at a constant speed, resulting in uniform thickness. A thin coating film can be formed.

In addition, in the description of the above embodiment, the position of the paint sprayers 2A, 2B is determined by providing the magnet G forming the detected object H on the parallel link 3A and detecting the magnet G with a plurality of magnetic sensors M-. Although the case of detection has been described, the present invention is not limited to this, and the present invention can be applied to any part that reciprocates synchronously with the coating machines 2A and 2B, such as the lifting frame and the connecting rod 5. In addition, as a non-contact sensor S, in addition to a magnetic sensor using a Hall element, a Hall IC
Binary resistance element, magnetic transistor, search coil.

It is also possible to use a magnetic sensor using a Wigand effect element, 5QUID or reed switch, a magnetic sensor using optical fiber, or a nuclear magnetic resonance type magnetic sensor. A partial waveform proximity sensor may be used, a capacitive proximity sensor may be used with the detected object H made of a dielectric substance, or the detected object H may be used as a drawn marker and detected with an optical sensor. It's okay.

Moreover, it goes without saying that the number of non-contact sensors S can be changed as appropriate in order to obtain the magnitude of the amplitude of the parallel link 3A and desired detection accuracy.

Further, in the above embodiment, the elevating frame 1 is connected to the parallel link 3A.
, 3B has been described, but the present invention is not limited to this, and can also be applied to a structure in which a slider is provided on an elevating frame, a coating machine is provided on the slider, and this slider is swung by a crank mechanism. can also be used.

〔effect〕

As described above, according to the present invention, by variably controlling the rotational speed of the motor that drives the crank according to the position of the paint sprayer, the moving speed of the paint sprayer can be maintained constant, and the crank It has the excellent effect of being able to perform coating with a uniform coating thickness even when it is driven back and forth.

[Brief explanation of drawings]

Fig. 1 is a flow sheet showing an example of an automatic painting device according to the present invention, and Fig. 2 <a) to (d) shows the position of the coating machine, the rotational speed of the motor, the moving speed of the coating machine, and the position of the Hashina valve, respectively. It is a graph showing an on-off state. Explanation of symbols 1・~Elevating frame, 2A, 2B−・Painting machine, 3A, 3
B.-parallel link, 4-crank, 5-.connecting loft, C-.crank mechanism, 6-motor, 8-.control device, 9-.position-speed conversion means, 11-.inverter, engineering 3
...Valve controller, S--Non-contact M sensor, M
・-・Magnetic sensor, H-・Detected object, G-・Magnet. Patent applicant Trinity Industries Co., Ltd. Agent

Claims (1)

[Claims] [1] Detecting the position of a detected object (H) provided at an arbitrary part that reciprocates synchronously with the paint machine (2A, 2B) that reciprocates by a crank mechanism (C) A plurality of non-contact sensors (S) are arranged along a trajectory along which the object to be detected (H) reciprocates, and
In order to make the reciprocating motion of the detected object (H
), and a position-speed conversion means (9) that sets the rotational speed of the crank drive motor (6) corresponding to the position of An automatic painting apparatus comprising: a control means (10) for varying the rotational speed of a crank drive motor (6) based on speed data. [2] The non-contact sensor (S) is a magnetic sensor (M ),
2. The automatic painting apparatus according to claim 1, which comprises an optical fiber-based magnetic sensor or a nuclear magnetic resonance type magnetic sensor, and wherein the detected object (H) comprises a magnet (G). [3] The automatic painting apparatus according to claim 1, wherein the non-contact sensor (S) is a high-frequency proximity sensor, and the detected object (H) is a metal proximity body. [4] The automatic painting apparatus according to claim 1, wherein the non-contact sensor (S) is a capacitive proximity sensor, and the detected object (H) is a proximity object made of a dielectric material. [5] The non-contact sensor (S) consists of an optical sensor,
The automatic painting apparatus according to claim 1, wherein the detected object (H) is a drawn marker.