JP2020179368A - Coating apparatus - Google Patents

Abstract

To minimize a trouble caused by collision between a coating gun and an object to be coated.SOLUTION: A coating apparatus includes a coating gun 25 for discharging powdered paint P toward an object W to be coated, a driving device 15 for moving the coating gun 25 in accordance with the shape of the object W to be coated, and an acceleration sensor 44 for detecting impact applied to the coating gun 25. When the object W to be coated collides with the coating gun 25, collision can be detected by the acceleration sensor 44. By stopping coating after collision, a trouble or a damage caused by collision between the coating gun 25 and the object W to be coated can be minimized.SELECTED DRAWING: Figure 2

Description

The present invention relates to a coating apparatus.

Patent Document 1 discloses a coating device that sprays powder coating material discharged from a coating gun onto an object to be coated that is conveyed by a conveyor. In this device, the size and shape of the object to be coated are detected just before the object to be coated enters the coating booth, and the detection signal is transmitted to the control device. The control device controls the discharge amount of the powder coating material from the coating gun based on the transmitted detection signal.

Japanese Unexamined Patent Publication No. 2011-156488

In this type of coating equipment, when the shape of the object to be coated is complicated or when trying to improve the coating quality of the surface to be coated, the shape and size of the object to be coated are three-dimensionally measured. It is conceivable to paint while moving the painting gun two-dimensionally or three-dimensionally based on the measured value. However, when the paint gun is moved two-dimensionally or three-dimensionally according to the shape of the object to be coated, the paint gun and the object to be coated change when the direction of the object to be coated suspended from the connector changes. There is concern about collision. If the paint gun is damaged by the collision with the object to be painted, all the objects to be painted after the collision may become defective.

The present invention has been completed based on the above circumstances, and an object of the present invention is to minimize defects caused by collision between a coating gun and an object to be coated.

The coating apparatus of the present invention
A paint gun that ejects paint toward the object to be painted,
A drive device that moves the coating gun according to the shape of the object to be coated,
It is equipped with an acceleration sensor that detects the impact acting on the paint gun.

When an object to be painted collides with the paint gun, the acceleration sensor can detect the collision. By stopping the painting after the collision, it is possible to minimize the defects and damages caused by the collision between the painting gun and the object to be painted.

It is external perspective view of the coating apparatus of Example 1. FIG. It is a perspective view which shows the disassembled state of a paint gun, a sensor module, and an arm. It is a partial notch side view showing the state where the sensor module and the paint gun are attached to the arm. FIG. 3 is a cross-sectional view taken along the line AA of FIG.

In the present invention, the acceleration sensor may be housed in a dustproof space. According to this configuration, it is possible to prevent the paint from adhering to the acceleration sensor.

In the present invention, the driving device may be provided with a tubular arm for supporting the coating gun at the front end portion, and the dustproof space may be provided inside the arm. According to this configuration, the accelerometer can be kept dustproof by utilizing the existing arm.

In the present invention, a connection port for supplying paint is provided on the rear end surface of the paint gun so as to project, and the front end portion of the arm surrounds the connection port with respect to the rear end portion of the paint gun. The acceleration sensor may be arranged at a position separated rearward from the connection port. According to this configuration, it is possible to prevent the connection port and the acceleration sensor from interfering with each other.

In the present invention, the sensor module is configured by assembling the acceleration sensor to the holding member, and the holding member may be detachable from the paint gun. According to this configuration, the attachment / detachment form of the sensor module to the paint gun can be selected according to the necessity of the acceleration sensor.

In the present invention, the holding member may have a tubular shape, and the acceleration sensor may be housed in the holding member. According to this configuration, the interference of foreign matter with the acceleration sensor can be prevented by the holding member.

In the present invention, an attachment portion for attaching the acceleration sensor is provided inside the holding member, and the inside of the holding member is provided with an accommodation space for accommodating the acceleration sensor and the coating gun by the attachment portion. It may be partitioned from the wiring space of the connecting wiring member. According to this configuration, it is possible to prevent the wiring member and the acceleration sensor from interfering with each other.

In the present invention, an opening capable of exposing the acceleration sensor may be formed in a region of the outer surface of the holding member corresponding to the mounting portion. According to this configuration, the acceleration sensor can be accommodated in the holding member through the opening and attached to the mounting portion.

In the present invention, the driving device may include a tubular arm for supporting the coating gun at a front end portion, and the sensor module may be housed in the arm. According to this configuration, the interference of foreign matter with the sensor module can be prevented by the arm.

<Example 1>
Hereinafter, Example 1 embodying the present invention will be described with reference to FIGS. 1 to 4. In the following description, regarding the front-back direction, the left side in FIGS. 2 and 3 is defined as the front. As for the vertical direction, the directions appearing in FIGS. 1 to 4 are defined as upward and downward as they are.

The coating apparatus of the first embodiment includes a conveyor 10 that conveys an object to be coated W, a coating gun 25 that discharges powder coating material P (the coating material according to the claim) toward the object to be coated W, and a coating gun 25. It is configured to include a driving device 15 for two-dimensionally moving the coating gun 25 and a sensor module 35 for detecting that the coating gun 25 collides with the object W to be coated.

The conveyor 10 includes a guide rail 11 arranged so as to extend horizontally, and a hanger 12 that moves in one direction along the guide rail 11. The object to be coated W is transported in one direction (from diagonally upper left to diagonally lower right in FIG. 1) while being suspended from the hanger 12. The object to be coated W has a shape having an uneven portion with respect to the driving device 15. A shape detection booth (not shown) is provided in the middle of the transport path of the object W to be coated, and a coating booth is provided downstream of the shape detection booth in the transport direction. At the shape detection booth, the shape of the object to be coated W to be transported is detected by a shape detection device (not shown).

A drive device 15 is provided in the painting booth. The drive device 15 has a housing 16 and an arm 18. A lifting mechanism (not shown) for moving the lifting member (not shown) in the vertical direction is provided in the housing 16. The elevating member is provided with an advancing / retreating mechanism (not shown) for moving the advancing / retreating member (not shown) in the front-rear direction.

The arm 18 is made of fiber reinforced plastic (FRP) and has a long cylindrical shape. The length of the arm 18 is, for example, about 1.2 m to 1.5 m. The outer diameter of the arm 18 is, for example, about 40 mm. The rear end portion (base end portion) of the arm 18 is attached so as to be able to move integrally with the advancing / retreating member. The arm 18 attached to the advancing / retreating member extends horizontally forward from the advancing / retreating member in a cantilevered manner with its axis directed in the front-rear direction (direction orthogonal to the transport direction of the object W to be coated).

The front end side portion of the arm 18 projects from the vertically slit-shaped groove 17 formed on the front surface of the housing 16 toward the front of the housing 16 toward the conveyor 10. An enlarged diameter portion 19 having an outer diameter larger than that of the arm 18 is integrally formed at the front end portion of the arm 18. Since the arm 18 has a cylindrical shape, the internal space of the arm 18 functions as a dustproof space 20.

A nut 21 made of synthetic resin is fitted on the arm 18. A female screw portion 22 is formed on the inner circumference of the nut 21. A ring-shaped pressing portion 23 concentric with the nut 21 is formed on the inner circumference of the rear end portion of the nut 21. Similarly, a tubular cover 24 is externally fitted to the arm 18. The cover 24 is arranged behind the nut 21.

The paint gun 25 and the sensor module 35 are attached to the front end portion (protruding end portion) of the arm 18 so that they can move integrally. The drive device 15 two-dimensionally moves the arm 18, the coating gun 25, and the sensor module 35 according to the shape of the object W to be coated, based on the three-dimensional data of the shape of the object W to be coated obtained at the shape detection booth. Let me. In other words, the arm 18, the coating gun 25, and the sensor module 35 move in the vertical direction and the front-rear direction according to the shape of the object to be coated W to be conveyed.

The paint gun 25 has an elongated shape in the front-rear direction as a whole. The paint gun 25 has a body 26 made of an insulating material in which a high voltage generator 27 is housed. A nozzle 28 for discharging the powder coating material P charged by the high voltage generator 27 is provided at the front end portion of the body 26. A connecting portion 29 is formed on the rear surface of the body 26 so as to project in a circular shape with the axis directed in the front-rear direction (that is, coaxial with the body 26). A male screw portion 30 is formed on the outer circumference of the connecting portion 29.

A connector 31 for supplying power and a connection port 32 for supplying paint are provided on the rear end surface (protruding end surface) of the connecting portion 29. A power supply cable 33 (arrangement member according to claim) for supplying electric power to the high voltage generator 27 is connected to the power supply connector 31. The connection port 32 has a form of protruding rearward from the rear end surface of the connecting portion 29 (painting gun 25). A paint hose 34 (arrangement member according to claim) for supplying powder paint P to a paint supply path (not shown) in the body 26 is connected to the connection port 32. A tubular cover 24 is attached to the rear end of the body 26 so as to surround the connecting portion 29, the connector 31, the connection port 32, the power supply cable 33, and the paint hose 34.

The sensor module 35 includes a metal holding member 36, a metal support plate 40 attached to the holding member 36, and an acceleration sensor 44 attached to the holding member 36 via the support plate 40. The holding member 36 has a cylindrical main body 37 whose axis is oriented in the front-rear direction (coaxial with the arm 18), and a concentric ring-shaped flange 38 formed on the outer periphery of the front end of the main body 37.

The outer diameter of the main body 37 is the same as the inner diameter of the arm 18. An opening 39 is formed on the outer periphery of the rear end portion of the main body portion 37. The opening 39 has a form of penetrating from the outer peripheral surface to the inner peripheral surface of the main body portion 37 (holding member 36). The opening shape when the opening 39 is viewed in the radial direction perpendicular to the axis of the holding member 36 is square. The outer diameter of the flange portion 38 is the same as the outer diameter of the enlarged diameter portion 19 of the arm 18.

The support plate 40 is made of a square flat plate and is a member for fixing the acceleration sensor 44 to the holding member 36. The support plate 40 is housed in the internal space of the main body 37 in a posture parallel to the axis of the holding member 36. Both side edges of the housed support plate 40 are fixed to the inner circumference of the rear end portion of the main body portion 37 by welding. The support plate 40 fixed to the main body 37 divides the rear end portion of the main body 37 in the internal space into a wiring space 42 and an accommodation space 43. The opening 39 is open so as to face the accommodation space 43. The surface of the support plate 40 on the side facing the accommodation space 43 functions as the mounting portion 41.

The acceleration sensor 44 is a rectangular parallelepiped and is attached to the support plate 40 by screws 45. The acceleration sensor 44 is accommodated in the accommodating space 43 from the outside of the main body portion 37 through the opening 39, and is mounted on the mounting portion 41. The mounted acceleration sensor 44 is fixed to the mounting portion 41 by screws 45. The acceleration sensor 44 fixed to the support plate 40 is integrated with the arm 18 and the coating gun 25. A sensor cable 46, which is a bundle of a power supply electric wire and a communication electric wire, is connected to the acceleration sensor 44. The sensor cable 46 connected to the acceleration sensor 44 is led out to the rear of the holding member 36.

The acceleration sensor 44 functions as a means for detecting that the object to be coated W conveyed by the conveyor 10 collides with the coating gun 25. The acceleration sensor 44 is an analog sensor using a piezoelectric element, and detects acceleration in three-dimensional directions (vertical direction, front-rear direction, and left-right direction) generated in the coating gun 25. The acceleration detected by the acceleration sensor 44 is output to a control device (not shown). Even when normal powder coating is performed without the coating gun 25 and the object W colliding with each other, in the process of moving the coating gun 25 and the arm 18 in the vertical direction and the front-rear direction, immediately before and after the change of direction. During acceleration / deceleration, the paint gun 25 is accelerated. The acceleration sensor 44 also detects the acceleration of the coating gun 25 during acceleration / deceleration.

Therefore, in the collision detection program of the control device, a threshold value having a value larger than the acceleration during acceleration / deceleration during normal painting is set. The control device determines that the coating gun 25 and the object to be coated W collide with each other when the acceleration value of the coating gun 25 detected by the acceleration sensor 44 exceeds the threshold value. When it is determined that the coating gun 25 and the object W to be coated have collided with each other, the control device stops the transfer of the object W to be coated by the conveyor 10 and the discharge of the powder coating material P from the coating gun 25.

The procedure for attaching the sensor module 35 and the paint gun 25 to the arm 18 will be described. A power supply cable 33, a paint hose 34, and a sensor cable 46 are inserted into the arm 18 in advance. The power supply cable 33 and the paint hose 34 are inserted into the wiring space 42 from behind the holding member 36 (sensor module 35) and connected to the connector 31 of the paint gun 25 and the connection port 32. The sensor cable 46 is inserted into the accommodation space 43 from behind the holding member 36 and connected to the acceleration sensor 44.

Next, the sensor module 35 is temporarily assembled to the arm 18. In the temporarily assembled state, the portion of the sensor module 35 excluding the front end portion (flange portion 38) (main body portion 37 of the holding member 36 and the acceleration sensor 44) is housed in the front end portion of the arm 18, and the rear surface of the flange portion 38 is accommodated. It abuts on the front surface of the enlarged diameter portion 19. The rear end portion of the paint gun 25 is positioned with respect to the sensor module 35 temporarily assembled on the arm 18. At the time of positioning, the rear end surface of the connecting portion 29 of the coating gun 25 is concentrically contacted with the front surface of the flange portion 38. After positioning the paint gun 25, the nut 21 fitted on the arm 18 is slid forward, and the female screw portion 22 of the nut 21 is screwed into the male screw portion 30 of the paint gun 25.

As the nut 21 is screwed in, the pressing portion 23 of the nut 21 comes into contact with the rear surface of the enlarged diameter portion 19 of the arm 18, and the connecting portion 29 is pressed against the flange portion 38. When the nut 21 is tightened from this state, the paint gun 25 is fixed to the arm 18 via the sensor module 35. The paint gun 25 and the sensor module 35 (holding member 36) come into direct contact with each other, and the sensor module 35 (holding member 36) and the arm 18 come into direct contact with each other. After tightening the nut 21 to the male screw portion 30, the cover 24 that has been fitted to the arm 18 in advance is slid forward, and the flange portion 38, the diameter-expanded portion 19, the front end portion of the arm 18, and the nut are provided by the cover 24. Surround 21. As described above, the assembly of the sensor module 35 and the paint gun 25 to the arm 18 is completed.

The coating apparatus of the first embodiment includes a coating gun 25 that discharges powder coating P toward an object to be coated, a drive device 15 that moves the coating gun 25 according to the shape of the object to be coated, and a coating gun 25. It is provided with an acceleration sensor 44 that detects an acting impact. When the object to be coated W suspended from the hanger 12 is transported in a state where the object to be coated W is turned horizontally or tilted, the facing distance between the coating gun 25 and the object to be coated W becomes incorrect and the coating is performed. Not only defects may occur, but also the coating gun 25 and the object to be coated W may collide with each other.

When a collision occurs, the acceleration detected by the acceleration sensor 44 exceeds the threshold value. Therefore, the control device determines that the collision has occurred, transports the object to be coated W, and drives the coating gun 25 by the driving device 15. , The discharge of the powder coating material P from the coating gun 25 is stopped. As a result, it is possible to prevent the poorly painted object W from being carried out.

Further, in a state where the sensor module 35 and the coating gun 25 are assembled to the arm 18, the connecting portion 29 abuts on the flange portion 38, and this abutting portion is fixed by the nut 21 made of synthetic resin, whereby the shear pin structure 47 (Easy destruction structure) is constructed. The breaking strength of the shear pin structure 47 is set to be smaller than the breaking strength of the coating gun 25 itself. When the impact acting on the paint gun 25 when the paint gun 25 and the object to be coated W collide exceeds the breaking strength of the shear pin structure 47, the nut 21 is broken and the paint gun 25 is separated from the sensor module 35 and the arm 18. To do. As a result, damage to the paint gun 25 is prevented.

Even when the coating gun 25 is detached from the sensor module 35 and the arm 18, the control device detects a collision between the coating gun 25 and the object W to be coated based on the detection signal of the acceleration sensor 44, so that the coating is stopped. Therefore, the painting process is not continued with the painting gun 25 detached from the arm 18.

In electrostatic powder coating, the constant current function installed as a countermeasure against electrostatic repulsion operates at a relatively high speed, so collision between the object W to be coated and the coating gun 25 is detected based on fluctuations in the corona discharge current. Cannot be adopted. However, although the coating apparatus of the first embodiment is a coating apparatus for electrostatic powder coating, it is possible to detect a collision between the object to be coated W and the coating gun 25 by using the acceleration sensor 44. doing. Furthermore, the collision is detected and the painting is stopped. Therefore, defects and damages caused by the collision between the coating gun 25 and the object to be coated can be minimized.

The drive device 15 is provided with a tubular arm 18 at the front end portion that supports the paint gun 25. A dustproof space 20 is provided inside the arm 18. The sensor module 35 is housed in the arm 18. When the sensor module 35 is assembled to the arm 18, the sensor module 35 (acceleration sensor 44) is housed in the dustproof space 20 of the arm 18, so that the arm 18 can prevent foreign matter from interfering with the sensor module 35. it can.

When the holding member 36 is not housed in the arm 18, the acceleration sensor 44 is exposed to the outside of the holding member 36 at the opening 39 of the holding member 36. However, since the rear end portion of the holding member 36 in which the opening 39 is formed is housed in the dustproof space 20, it is possible to prevent the powder coating material P from adhering to the acceleration sensor 44 during painting. Since the existing arm 18 is used as a means for protecting the acceleration sensor 44 from the powder coating material P, the number of parts can be reduced and the structure can be simplified.

A connection port 32 for supplying paint is provided on the rear end surface of the paint gun 25 so as to project. The front end portion of the arm 18 is attached so as to surround the connection port 32 with respect to the rear end portion (connecting portion 29) of the paint gun 25 via the holding member 36 (sensor module 35). The connection port 32 is housed in the front end of the holding member 36, and the acceleration sensor 44 is housed in the rear end of the holding member 36. That is, the acceleration sensor 44 is arranged at a position separated rearward from the connection port 32. According to this configuration, it is possible to prevent the connection port 32 and the acceleration sensor 44 from interfering with each other.

The sensor module 35 is configured by assembling the acceleration sensor 44 to the holding member 36. The sensor module 35 is attached to the coating gun 25 by tightening the fastening member (nut 21 and the male screw portion 30), and can be removed from the coating gun 25 by loosening the fastening member. Further, the paint gun 25 can be directly attached to the arm 18 without using the sensor module 35. In this case, the enlarged diameter portion 19 may be brought into coaxial contact with the rear end surface of the connecting portion 29, and the nut 21 may be screwed into the male screw portion 30. Since the sensor module 35 can be attached to and detached from the paint gun 25, the form of attaching and detaching the sensor module 35 to and from the paint gun 25 can be selected according to the necessity of the acceleration sensor 44.

The holding member 36 has a tubular shape, and the acceleration sensor 44 is housed in the holding member 36. According to this configuration, the holding member 36 can prevent the interference of foreign matter with the acceleration sensor 44 even when the sensor module 35 is not housed in the arm 18.

An attachment portion 41 (support plate 40) for attaching the acceleration sensor 44 is provided inside the holding member 36, and the inside of the holding member 36 accommodates the acceleration sensor 44 by the attachment portion 41 (support plate 40). It is partitioned into a storage space 43 and a wiring space 42 of a wiring member (power supply cable 33 and paint hose 34) connected to the painting gun 25. According to this configuration, it is possible to prevent the acceleration sensor 44 from interfering with the wiring member (power feeding cable 33 or paint hose 34).

Since an opening 39 capable of exposing the acceleration sensor 44 is formed in a region of the outer surface of the holding member 36 corresponding to the mounting portion 41, the acceleration sensor 44 can be moved from the opening 39 to the inside of the holding member 36. It can be attached to the attachment portion 41 by accommodating it in. Therefore, when the acceleration sensor 44 fails, the work of replacing the acceleration sensor 44 through the opening 39 can be performed.

<Other Examples>
The present invention is not limited to the examples described by the above description and drawings, and for example, the following examples are also included in the technical scope of the present invention.
In the above embodiment, the acceleration sensor is housed in the dustproof space, but the acceleration sensor may be arranged in a state of being exposed in the space where the powder coating material floats.
In the above embodiment, the dustproof space is provided inside the arm, but the dustproof space may be provided outside the arm (for example, inside the paint gun).
In the above embodiment, the sensor module is housed in the arm, but the sensor module may be arranged outside the arm.
In the above embodiment, the holding member of the sensor module is attached to the paint gun in a state of being in contact with the arm, but the holding member may be attached to the paint gun in a state of not being in contact with the arm.
In the above embodiment, the sensor module is attached in contact with the paint gun, but the sensor module may be attached to the arm without contacting the paint gun.
In the above embodiment, the holding member of the sensor module has a tubular shape, but the holding member may have a shape other than the cylinder, such as a box shape or a flat plate shape.
In the above embodiment, the accommodating space for accommodating the acceleration sensor is secured inside the holding member of the sensor module, but the holding member may be in a form having no accommodating space.
In the above embodiment, the holding member has a mounting portion and an opening, but the holding member may have an opening without a mounting portion or may have a mounting portion without an opening. ..
In the above embodiment, the inside of the holding member is partitioned into a space for accommodating the acceleration sensor and a space for arranging the wiring member, but the acceleration sensor and the wiring member may be accommodated in one common space. ..
In the above embodiment, the drive device moves the painting gun based on the detection information of the shape detection device provided in front of the painting booth, but the drive device has taught in advance about the shape of the object to be coated. The paint gun may be moved based on the information.
In the above embodiment, the paint gun is moved two-dimensionally in the vertical direction and the front-rear direction, but the paint gun may be moved three-dimensionally in the vertical direction, the front-back direction, and the left-right direction.
In the above embodiment, the case where it is applied to a coating device for electrostatic powder coating has been described, but the present invention can also be applied to a non-electrostatic coating device and an electrostatic coating device using a liquid paint.

P ... Powder paint (paint)
W ... Object 15 ... Drive device 18 ... Arm 20 ... Dustproof space 25 ... Paint gun 32 ... Connection port 33 ... Power supply cable (routing member)
34 ... Paint hose (routing member)
35 ... Sensor module 36 ... Holding member 39 ... Opening 41 ... Mounting part 42 ... Arrangement space 43 ... Accommodation space 44 ... Acceleration sensor

Claims (9)

A paint gun that ejects paint toward the object to be painted,
A drive device that moves the coating gun according to the shape of the object to be coated,
A painting apparatus including an acceleration sensor that detects an impact acting on the painting gun. The coating apparatus according to claim 1, wherein the acceleration sensor is housed in a dustproof space. The drive device has a tubular arm at the front end that supports the paint gun.
The coating apparatus according to claim 2, wherein the dustproof space is provided inside the arm. A connection port for supplying paint is provided on the rear end surface of the paint gun so as to project.
The front end of the arm is attached to the rear end of the paint gun so as to surround the connection port.
The coating apparatus according to claim 3, wherein the acceleration sensor is arranged at a position separated rearward from the connection port. A sensor module is configured by assembling the acceleration sensor to the holding member.
The coating apparatus according to any one of claims 1 to 4, wherein the holding member is removable from the coating gun. The coating apparatus according to claim 5, wherein the holding member has a tubular shape, and the acceleration sensor is housed in the holding member. A mounting portion for mounting the acceleration sensor is provided inside the holding member.
5. The inside of the holding member is partitioned by the mounting portion into a storage space for accommodating the acceleration sensor and a wiring space for a wiring member connected to the coating gun. Or the coating apparatus according to claim 6. The coating apparatus according to claim 7, wherein an opening capable of exposing the acceleration sensor is formed in a region of the outer surface of the holding member corresponding to the mounting portion. The drive device has a tubular arm at the front end that supports the paint gun.
The coating apparatus according to any one of claims 5 to 8, wherein the sensor module is housed in the arm.

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