Liquid material discharge device and coating device

Abstract

[Problem] To provide: a liquid material discharge device which can be mounted on various robots without being limited to a specific robot while having good replacement workability of a storage container and responsiveness at the time of switching pressure applied to a liquid material; and a coating device equipped with the liquid material discharge device. [Solution] A liquid material discharge device 1 comprises: a main device 10; a switching device 20 which is physically separated from the main device 10 and supplies air into a storage container communicating with a nozzle; and a buffer device 22, wherein the main device 10 includes a pressurized air regulation device 12 for adjusting pressurized air to a desired pressure, and a control device 11, the switching device 20 includes a discharge valve 21 for switching communication or cutoff of a flow path connected to the pressurized air regulation device 12 and the storage container 50, the main device 10 and the switching device 20 are connected by a flexible air supply path 32 so as to be able to change a relative position, and the buffer device 22 is disposed inside switching device 20 or so as to be connected to the switching device. A coating device 40 is equipped with said liquid material discharge device.

Description

Liquid material ejection device and coating device

[0001] The present invention relates to a liquid material discharge device that discharges a liquid material by supplying pressurized air to a storage container that communicates with a nozzle, and to a coating apparatus that includes the same device.

[0002] There is a device called an air-operated dispenser that supplies pressurized gas to a storage container connected to a nozzle to dispense a liquid material from the storage container. Patent Document 1 discloses an air-operated dispenser equipped with a pressure reducing valve, a buffer tank, and a discharge valve. The provision of a buffer tank prevents a sudden decrease in pressure in the pipeline when the discharge valve is operated, and allows the pressure in the storage container to be rapidly increased, thereby achieving the pressure required to obtain the desired discharge rate in a short period of time. Additionally, Patent Document 1 proposes that the flow resistance of the flow path connecting the buffer tank and the storage container be made greater than the flow resistance of the flow path connecting the buffer tank and the pressure reducing valve, thereby reducing the pressure drop in the flow path supplying compressed gas to the liquid storage container that occurs when the pressure reducing valve is activated.

[0003] An air dispenser may be mounted on a robot that moves the nozzle and the object relative to each other, and used to apply a desired liquid to the object. Patent Document 2 discloses a liquid material application device equipped with a tabletop robot equipped with a dispenser including an air dispenser. In such a liquid material application device, a storage container communicating with the nozzle is mounted on a holder that is installed so as to move up and down relative to the head, and a dispense controller is installed at a position away from the movable head. When mounted on a large robot, the distance between the movable head and the dispense controller may be 5 to 10 meters.

[0004] 13 is a block diagram illustrating a conventional dispense controller 900. The dispense controller 900 includes a control device 901, a pressure regulator 902, a buffer tank 903, and a discharge valve 904, and is connected to a storage container 910 having a discharge port via an adapter tube 911. Pressurized air supplied from an air supply source 905 is adjusted in pressure by the pressure regulator 902 and supplied to the discharge valve 904 via the buffer tank 903. The discharge valve 904 controls the dispensing operation of the liquid material by switching between communication and cut-off between the adapter tube 911 and the buffer tank 903 according to a signal from the control device 901.

[0005] Japanese Patent Application Laid-Open No. 2010-279867 International Publication No. 2015 / 083722 Pamphlet

[0006] In conventional liquid material application devices, the dispense controller is installed at a location distant from the storage container that communicates with the nozzle. The distance between the dispense controller and the storage container causes problems, such as poor responsiveness at the start and end of dispensing. For example, even if the storage container and the pressure regulator are connected by the switching valve at the start of dispensing, the distance between the switching valve and the storage container means that it takes time to achieve the desired pressure in the storage container. Furthermore, when depressurizing the storage container at the end of dispensing, it takes time to exhaust the air in the storage container via the switching valve, which means that the dispensing of the liquid material from the discharge port does not stop promptly.

[0007] On the other hand, if a heavy object is added to the holder that holds the storage container, the inertial force when moving the holder increases, resulting in poor responsiveness when moving and stopping the holder. In order to suppress this inertial force, it becomes necessary to enlarge the drive device that moves the holder. This restricts the holder that holds the storage container in that it cannot be equipped with a heavy object. Even if the holder does not move, it may not be possible to place something as large as a dispense controller near the holder. Furthermore, since the storage container needs to be replaced when the remaining amount of liquid material becomes low, it is also important to ensure that the ease of replacement is not impaired.

[0008] The present invention aims to provide a liquid material ejection device that has good responsiveness at the start and end of ejection and good workability in replacing the storage container, yet is not limited to a specific robot and can be mounted on various robots, and an application device equipped with the same device.

[0009] The liquid material dispensing device of the present invention comprises the following technical means: [1] A liquid material dispensing device comprising: a main unit connected to an air supply source; a switching device physically separate from the main unit and supplying air into a reservoir container communicating with a nozzle; and a buffer device, wherein the main unit comprises a pressurized air regulator that regulates the pressurized air supplied from the air supply source to a desired pressure; and a control device, the switching device comprising a discharge valve that switches between communication and blocking of a flow path connecting the pressurized air regulator and the reservoir container, the main unit and the switching device being connected by an air supply path that is at least partially flexible so that their relative positions can be changed, and the buffer device being disposed within the switching device or directly or indirectly connected to the switching device. [2] The liquid material dispensing device described in [1], wherein the total length of the flow path connecting the discharge valve and the buffer device is 50 cm or less. [3] The liquid material discharging device according to [1] or [2], further comprising a connector or attachment for attaching the switching device to a robot that moves the storage container relative to a workpiece. [4] The liquid material discharging device according to any one of [1] to [3], characterized in that the switching device comprises a case that houses the discharge valve, and the buffer device comprises a container provided within the case of the switching device. [5] The liquid material discharging device according to any one of [1] to [4], characterized in that the switching device comprises a case that houses the discharge valve, and the buffer device comprises a container provided outside the case of the switching device. [6] The liquid material discharging device according to [5], characterized in that it comprises a connector or attachment for attaching the buffer device to the case. [7] The liquid material discharging device according to any one of [1] to [6], characterized in that the switching device comprises an output joint that is fluidly connected to the discharge valve and that connects an air supply pipe to which a storage container is connected. [8] The liquid material discharging device according to any one of [1] to [7], characterized in that the pressurized air pressure adjusting device comprises a pressure regulator.[9] The liquid material discharging device according to any one of [1] to [8], wherein the discharge valve includes at least one pilot valve.

[10] The liquid material discharging device according to [9], wherein the main device is provided with a pilot air pressure adjusting device that supplies pilot pressure to the pilot valve.

[11] The liquid material discharging device according to

[10] , wherein the pilot air pressure adjusting device includes a pressure regulator.

[12] The liquid material discharging device according to any one of [1] to

[11] , wherein the discharge valve is a multi-way valve.

[13] The liquid material discharging device according to any one of [1] to

[12] , wherein the discharge valve is a plurality of solenoid valves.

[14] The liquid material discharging device according to any one of [1] to

[13] , wherein a pressure sensor is provided in a flow path connecting the storage container and the discharge valve, and the control device controls the discharge valve based on the measurement value of the pressure sensor.

[15] The liquid material discharging device according to any one of [1] to

[14] , wherein the discharge valve is capable of switching between communication between the pressurized air adjusting device and the storage container and communication between the atmosphere and the storage container.

[16] The liquid material discharging device according to any one of [1] to

[15] , wherein the main device includes a negative pressure air supply device that supplies negative pressure, the negative pressure air supply device and the discharge valve are connected by an at least partially flexible negative pressure air supply path, and the discharge valve is capable of switching between communication between the pressurized air adjusting device and the storage container and communication between the negative pressure air supply device and the storage container.

[17] The liquid material discharging device according to

[16] , wherein the negative pressure air supply device includes an ejector.

[18] The liquid material discharging device according to

[17] , wherein the negative pressure air supply device includes a pressure regulator provided between the ejector and the air supply source.

[19] A coating device comprising the liquid material discharge device according to any one of [1] to

[18] , a robot having a holder for holding the storage container and moving the holder and an object to be coated relatively, and a flexible air supply pipe connecting the liquid material discharge device and the storage container.

[20] The coating device according to

[19] , further comprising a connector or attachment for attaching the switching device to the robot.

[21] The coating device according to

[20] , characterized in that the connector or attachment is a connector or attachment for attaching the switching device to a movable head having the holder.

[22] The coating device according to

[20] or

[21] , characterized in that the robot comprises a beam member on which a movable head having the holder is mounted, and the connector or attachment is a connector or attachment for attaching the switching device to the beam member.

[0010] According to the present invention, it is possible to provide a liquid material ejection device that has good responsiveness at the start and end of ejection and good workability in replacing the storage container, yet is not limited to a specific robot and can be mounted on various robots, and an application device equipped with the same device.

[0011] FIG. 1 is a block diagram of a liquid material discharging device of a first embodiment. FIG. 2 is a perspective view showing a state in which a storage container and an adapter tube are attached to the liquid material discharging device of the first embodiment. FIG. 3 is a sectional side view of a main part illustrating the configuration of a storage container and an air supply path. FIG. 4 is a perspective view showing an application device equipped with the liquid material discharging device of the first embodiment. FIG. 5 is a block diagram of a liquid material discharging device of a second embodiment. FIG. 6 is a perspective view showing the liquid material discharging device of the second embodiment. FIG. 7 is a perspective view showing an application device equipped with the liquid material discharging device of the second embodiment. FIG. 8 is a block diagram of a liquid material discharging device of a third embodiment. FIG. 9 is a perspective view showing the liquid material discharging device of the third embodiment. FIG. 10 is a block diagram of a liquid material discharging device of a fourth embodiment. FIG. 11 is a perspective view showing the liquid material discharging device of the fourth embodiment. FIG. 12 is a perspective view showing the liquid material discharging device of the fourth embodiment. FIG. 13 is a perspective view showing an application device equipped with the liquid material discharging device of the fifth embodiment. FIG. 14 is a block diagram of a conventional liquid material discharging device.

[0012] Embodiments of the present invention will be described below with reference to the drawings. First Embodiment As shown in FIG. 1 , a liquid material dispensing apparatus 1 according to a first embodiment includes a main unit 10 and a switching unit 20. The main unit 10 includes a control device 11, a pressurized air pressure regulator 12, and a case 13. The control device 11 includes a processing device (not shown) and a storage device (not shown) storing a control program. The control device 11 is connected to the pressurized air pressure regulator 12 via a signal cable 15 and to the discharge valve 21 via a flexible signal cable 31, and controls their operation. As in a third embodiment described below, the switching unit 20 may include a second control device capable of wireless communication with the control device 11, and the second control device may control the operation of the discharge valve 21. Furthermore, the signal cables within the main unit 10 and the switching unit 20 do not have to be in the form of cables, as long as they are capable of transmitting signals. For example, they may be configured using conductors formed on a substrate, direct contact between contacts, or wirelessly.

[0013] The pressurized air regulator 12 is connected upstream to the air supply source 70 via a first air supply path 14 and downstream to the buffer device 22 of the switching device 20 via a second air supply path 32. The first air supply path 14 may be configured with flexible or non-flexible piping, or may be configured with a flow path formed in a block. The second air supply path 32 is configured, for example, with flexible piping. The pressurized air regulator 12 is equipped with a pressure regulator and reduces the high-pressure air supplied from the air supply source 70 to a set pressure value before supplying it to the second air supply path 32. The air supply source 70 may be, for example, a known air compressor. The main unit 10 and the air supply source 70 are detachably connected by detachably connecting the first air supply path 14 of the main unit 10 to the air supply source 70 via a connector (not shown).

[0014] As shown in Fig. 2, an operation unit including a touch panel, operation buttons, etc. is provided on the front side of the case 13 for setting the discharge operation, discharge conditions, etc. An input / output port (not shown in Fig. 2) for electrically connecting to an external device and an input / output port (not shown in Fig. 2) for connecting to an air pipe are provided on the front side or rear side of the case 13. The operation unit may be physically separated from the main unit 10 and configured to give instructions via wired or wireless communication.

[0015] The switching device 20 includes a discharge valve 21, a buffer device 22, and a case 23. The upstream side of the discharge valve 21 is connected to the buffer device 22 by a third air supply path 33, and the downstream side is connected to the output joint 24 by a fourth air supply path 34. The third air supply path 33 and the fourth air supply path 34 may be configured with flexible or non-flexible piping, or may be configured with flow paths formed in a block.

[0016] The discharge valve 21 of this embodiment is a switching valve (three-way valve) that is housed in a case 23 and has a first position that connects the storage container 50 to the buffer device 22 and a second position that connects the storage container 50 to the atmosphere. Note that the discharge valve of the switching device 20 may be configured as a multi-way valve such as a three-way valve that also functions as an exhaust valve, or may be configured by combining a plurality of electromagnetic valves such as on-off valves or switching valves, and such valve devices are also included in the discharge valve of the present invention.

[0017] The buffer device 22 is configured as a tank having a shape such as a sphere, a cylinder, a tube, or a coil, and is housed in the case 23. The buffer device 22 may be configured by combining a plurality of containers. The total capacity of the containers included in the buffer device 22 is, for example, 0.7 to 25 times or 1 to 10 times the capacity of the storage container 50. By providing the buffer device 22 between the flow path connecting the storage container 50 and the pressurized air pressure adjusting device 12, a sudden decrease in pressure within the flow path that occurs when the discharge valve 21 is switched can be prevented, and the pressure within the storage container can be rapidly increased, thereby achieving the pressure required to obtain the desired discharge amount in a short period of time.

[0018] On the other hand, if the distance between the buffer device 22 and the storage container 50 is large, there may be a delay in the effect of suppressing pressure reduction by the buffer device 22. In order to enable the desired pressure to be quickly applied inside the storage container 50 at the start of discharge, the distance between the adapter 61 attached to the upper end of the storage container 50 and the outlet of the buffer device 22 is configured to be, for example, 200 cm or less (preferably 150 cm or less, more preferably 120 cm or less).

[0019] As shown in FIG. 2 , the switching device 20 communicates with the storage container 50 via an adapter tube 60 connected to the output joint 24. FIG. 3 is a cross-sectional side view of essential parts illustrating the configuration of the storage container 50 and the adapter tube 60. The adapter tube 60 is composed of an adapter 61 attached to the upper end of the storage container 50, an air supply path 62, and a joint connector 63. The adapter 61 is detachably attached to a pair of flanges provided at the upper end of the storage container 50, making the interior of the storage container 50 a closed space. The air supply path 62 connected to the adapter 61 is a flexible tube that supplies pressurized air, the pressure of which has been adjusted via the switching device 20, to the storage container 50. The joint connector 63 allows the air supply path 62 to be detachably connected to the output joint 24.

[0020] The storage container 50 is replaced when the remaining amount of liquid material falls below a certain level. From the perspective of ease of replacement, it is preferable to arrange the storage container 50 and the switching device 20 at a certain distance (e.g., 10 cm or more, preferably 20 cm or more, more preferably 30 cm or more), and accordingly, the air supply path 62 is set to a certain length or more (e.g., 10 cm or more, preferably 20 cm or more, more preferably 30 cm or more). The length of the air supply path 62 of the adapter tube 60 can be selected from various lengths depending on the environment and robot used. In light of this, it is preferable to shorten the distance between the output joint 24 and the outlet of the buffer device 22, as this allows for a wider tolerance for the length of the air supply path 62 of the adapter tube 60.

[0021] The storage container 50 is a known storage container and includes an inner cylinder with a lower opening at its bottom end and an outer cylinder surrounding the inner cylinder. A nozzle 51 having a discharge port 52 at its tip is attached to the inner cylinder of the storage container 50. By supplying pressurized air from an adapter tube 60 into the storage container 50, the liquid material in the storage container 50 can be discharged from the discharge port 52. The storage container 50 is moved relative to the workpiece W, and applies the liquid to the workpiece W according to a coating pattern stored in the control device 11 or a robot controller (not shown). At the end of the coating operation, the supply of pressurized air to the storage container 50 is stopped and the pressurized air in the storage container is discharged, thereby stopping the discharge of the liquid material from the discharge port 52.

[0022] An example of how the liquid material discharging device 1 of the first embodiment is used will now be described. The liquid material discharging device 1 of this embodiment is mounted on various robots and used as a coating device. Robots to which the present invention can be applied include at least a head that holds a storage container that communicates with the nozzle, a relative drive device that moves the workpiece and the nozzle relative to each other, and a robot controller that controls the operation of the relative drive device. FIG. 4 shows a perspective view of a coating device 40 equipped with the liquid material discharging device 1 of the first embodiment, as an example. The coating device 40 is a tabletop robot that mainly includes a base 41, relative drive devices (42 to 44), and a movable head 45.

[0023] The relative drive device is composed of an X-direction drive device 42, a Y-direction drive device 43, and a Z-direction drive device 44. The X-direction drive device 42 has a beam member 42a supported by two columns, and can move the movable head 45 back and forth in the X direction 81. The movable head 45 attached to the beam member 42a has a Z-direction drive device 44 having a holder attached to the lower front side, and a switching device 20 attached to the side.

[0024] The case 23 in this embodiment is attached to the movable head 45 by connectors such as screws or attachments (mounting devices). Various devices such as distance sensors and cameras may be provided on the movable head 45 near the storage container 50, but since the switching device 20 is attached to the top of the movable head 45 and the Z-direction drive device 44 that holds the storage container 50 is attached to the bottom of the movable head 45, space is secured near the storage container 50 for adding various devices.

[0025] The Z-direction driving device 44 can move the storage container 50 attached to its holder 44a forward and backward in the Z direction (vertical direction) 83. The Z-direction driving device 44 only needs to move the storage container 50, and does not need to move the switching device 20, so a large driving force is not required and the device can be made compact.

[0026] A Y-direction driving device 43 provided on the base 41 can move the work table 46 forward and backward in a Y-direction 82 perpendicular to the X-direction 81. The work table 46 is made of a plate-shaped member and is provided with a mechanism (not shown) for fixing the work W. The XYZ-direction driving devices 42 to 44 can be configured using, for example, a combination of an electric motor (such as a servo motor or a stepping motor) and a ball screw, or a linear motor.

[0027] The switching device 20 is detachably attached to the side of the upper part of the movable head 45 and moves together with the movable head 45. The signal cable 31 and second air supply path 32 connecting the switching device 20 and the main unit 10 are flexible and have a length that allows them to follow the movement of the movable head 45, so that the movement of the switching device 20 is not restricted by the signal cable 31 and the second air supply path 32. The signal cable 31 and the second air supply path 32 are 0.85 to 100 times longer than the adapter tube 60, for example, 0.85 m to 10 m, and preferably 1.2 m to 10 m. The signal cable 31 and the second air supply path 32 may be bundled with a cable tie or the like as long as they do not restrict the movement of the movable head 45.

[0028] The switching device 20 is configured as a separate entity from the main device 10, and has a high degree of freedom in its installation position, allowing it to be mounted on any type of robot. The mounting position of the switching device 20 on the movable head 45 is not limited to the side shown in the figure, and it may be mounted on the top surface or other side surface of the movable head 45. Furthermore, as long as it does not interfere with the coating operation, the switching device 20 may be appropriately disposed in a location other than the movable head, such as on the beam member 42a or on a support pillar supporting the beam member 42a.

[0029] The main unit 10 is connected to a robot controller (not shown) in the stand 41 via a signal cable 35. The robot controller controls the operation of the relative drive devices (42 to 44) and sends discharge start commands and discharge end commands to the control device 11 of the main unit 10. The control device 11 may have a function to automatically calculate the pressure value and application time of the pressurized air to be applied to the storage container 50 based on the movement speed of the movable head 45 received from the robot controller via the signal cable 35. When the pressure value and application time of the pressurized air are sent from the main unit 10 to the switching device 20, the pressurized air adjusted by the pressurized air pressure adjusting device 12 is supplied to the storage container 50 via the adapter tube 60 at a predetermined timing.

[0030] In the coating device 40 of the first embodiment described above, the distance between the output joint 24 and the outlet of the buffer device 22 is short, and therefore the distance between the upper end of the storage container 50 and the outlet of the buffer device 22 is short (for example, 200 cm or less), making it possible to improve the responsiveness of air pressure control at the start and end of discharge. Furthermore, because the storage container 50 and the switching device 20 are separated by a certain distance (not too close) and are connected by a flexible adapter tube 60, the storage container 50 can be easily replaced and the risk of liquid material adhering to the switching device 20 during replacement can be reduced.

[0031] 5 is different from the liquid material discharge device 1 of the first embodiment in that the buffer device 122 is not housed in the case 123. The following description will focus on the differences from the first embodiment, and common features will be given the same reference numerals as in the first embodiment, and description thereof will be omitted.

[0032] As shown in Fig. 5, in the liquid material discharging device 90 of the second embodiment, a buffer device 122 is provided outside a case 123 of a switching device 120. In the second embodiment, a structure is adopted in which the buffer device 122 is provided outside the case 123, so the capacity of the buffer device 122 is not limited by the capacity of the case 123. Although the buffer device 122 and the case 123 are depicted as being separated from each other in Fig. 5, in reality the buffer device 122 is attached to the case 123 by connectors such as screws or attachments (mounting fixtures) not shown (see Fig. 6).

[0033] The input port of the buffer device 122 is connected to the pressurized air pressure adjusting device 12 via a second air supply path 132, and the output port is connected to the discharge valve 121 via a third air supply path 133. The overall length of the third air supply path 133 is 50 cm or less, preferably 40 cm or less, and more preferably 30 cm or less. The discharge valve 121 of this embodiment is housed in a case 123 and is a switching valve (three-way valve) having a first position that connects the storage container 50 and the buffer device 122 to each other, and a second position that connects the storage container 50 to the atmosphere.

[0034] 6 is a perspective view showing a liquid material discharging device 90 of the second embodiment. The main unit 10 is the same as that of the first embodiment. The switching device 120 has an output joint 124 provided at the bottom of the front side of the case 123, and a buffer device 122 attached to the top of the rear side of the case 123. A flexible signal cable 131 is connected to the bottom of the rear side of the case 123. A flexible second air supply path 132 is connected to the top surface of the buffer device 122. The air supply path provided inside the switching device 120 may be composed of flexible or non-flexible piping, or may be composed of a flow path formed in a block.

[0035] FIG. 7 is a perspective view of a coating device 91 equipped with a liquid material discharging device 90 according to a second embodiment. As shown in FIG. 7 , the case 123 of the switching device 120 is attached to the side of the movable head 45. However, the attachment position is not limited to the illustrated position, as in the first embodiment. In FIG. 7 , the buffer device 122 is attached to the rear side of the case 123. However, the attachment position is not limited to the illustrated side and may be attached to the top or other side of the case 123. Also, while FIG. 7 illustrates the buffer device 122 as a cylindrical tank, the shape of the buffer device 122 is not limited thereto. For example, the buffer device 122 may be a tank with a spherical, cylindrical, tubular, or coiled shape. The buffer device 122 may be directly connected to the case 123 with a connector such as a screw, or indirectly connected via an attachment (mounting fixture) that holds the buffer device 122. Alternatively, a rigid joint that constitutes part or all of the third air supply path 133 may be extended from the case 123, and the buffer device 122 may be attached to this joint.

[0036] The coating device 91 of the second embodiment described above also has good responsiveness to air pressure control at the start and end of discharge because the storage container 50 and the buffer device 122 are close to each other. Furthermore, because the size of the buffer device 122 is not limited by the size of the case 123, the buffer device 122 can have a larger capacity than that of the first embodiment.

[0037] Furthermore, even when the buffer device 122 is configured with multiple tanks, the capacity of the buffer device 122 can be easily expanded by connecting the tanks outside the case 123. In this case, some of the tanks may be disposed inside the case 123 and the remaining tanks may be disposed outside the case 123. Note that when the buffer device 122 is configured with multiple tanks, as long as some of the tanks are disposed inside the case 123 or so as to be directly or indirectly connected to the case 123, the remaining tanks may be disposed in a location away from the case 123, such as within the main unit 10.

[0038] Third Embodiment The liquid material discharging device 100 of the third embodiment shown in Figure 8 includes a main device 310 and a switching device 320. The liquid material discharging device 100 of this example is also mounted on various robots and used as a coating device. As an example, the liquid material discharging device 100 is mounted on a tabletop robot that mainly includes a base 41, relative drive devices (42 to 44), and a movable head 45 and used as a coating device (see Figure 4).

[0039] The main unit 310 includes a first control device 311, a first pressurized air pressure regulator 312, a pilot air pressure regulator 313, a second pressurized air pressure regulator 314, an ejector 315, and a case 316. The first control device 311 includes a processing device (not shown) and a storage device (not shown) that stores a main control program. The first control device 311 is connected to the first pressurized air pressure regulator 312, the pilot air pressure regulator 313, and the second pressurized air pressure regulator 314 via signal cables 317 to 319, and controls the operation of these devices. The first control device 311 is also configured to be able to communicate with a second control device 321 via a signal cable 331. Note that a wireless communication module may be provided in each of the first control device 311 and the second control device 321, allowing wireless communication without the signal cable 331.

[0040] The first pressurized air adjusting device 312 is equipped with a pressure regulator and reduces the pressure of the high-pressure air supplied from the air supply source 70 via the first air supply path 333 to a set pressure value and supplies it to the second air supply path 334.

[0041] The pilot air pressure regulator 313 is connected to the air supply source 70 and is a pressure regulator that supplies a pilot pressure to a pilot pipe 335 for controlling the operation of a switching valve 322 and an exhaust valve 324, which will be described later. The switching valve 322 and the exhaust valve 324, which will be described later, both employ pilot-type solenoid valves, and open and close the switching valve 322 and the exhaust valve 324 with the help of air supplied from the pilot air pressure regulator 313. Note that if the magnitude of the pilot pressure required by the pilot-type solenoid valve is the same as the pressure of the air supply source 70, the pilot air pressure regulator 313 may be omitted and the pilot pipe 335 may be branched off from the first air supply path 333 to supply the pilot pressure to the pilot-type solenoid valve.

[0042] Furthermore, as a configuration in which the pilot air pressure adjusting device 313 is not provided, instead of branching the pilot piping 335 from the first air supply path 333, the pilot piping 335 may be branched from the second air supply pipe 334 downstream of the first pressurized air pressure adjusting device 312, the buffer device 323, the air supply path 339, or the like. In this case, if the pilot piping 335 is branched within the switching device 320, the pilot piping 335 between the main device 310 and the switching device 320 can be made unnecessary.

[0043] The second pressurized air regulator 314 and the ejector 315 constitute a negative pressure air supply device. More specifically, the second pressurized air regulator 314 includes a pressure regulator and generates negative pressure in the negative pressure supply path 332 by releasing pressurized air supplied from the air supply source 70 into the outside air via the ejector 315. The negative pressure supply path 332 is formed, for example, by flexible piping. The air supply path and negative pressure supply path provided inside the main unit 310 and the switching device 320, respectively, may be formed by flexible or non-flexible piping, or may be formed by flow paths formed in a block. The main unit 310 and the air supply source 70 are detachably connected by detachably connecting the first air supply path 333 of the main unit 310 to the air supply source 70 via a connector (not shown).

[0044] 9, an operation unit consisting of a touch panel, operation buttons, etc. is provided on the front side of the case 316 for setting the discharge operation and discharge conditions, and an input / output port (not shown in FIG. 9) for electrically connecting to an external device and an input / output port (not shown in FIG. 9) for connecting to an air pipe are provided on the front or rear side of the case 316. The signal cable 331, negative pressure supply path 332, second air supply path 334, and pilot pipe 335 that connect the main unit 310 and the switching device 320 are all flexible, so that they do not restrict movement when the relative positions of the main unit 310 and the switching device 320 are changed.

[0045] The switching device 320 includes a second control device 321, a switching valve 322, a buffer device 323, an exhaust valve 324, a pressure sensor 325, and a case 326. The second control device 321 is connected to the switching valve 322, the exhaust valve 324, and the pressure sensor 325 via signal cables 336 to 338, and controls the operations of these devices.

[0046] The switching valve 322 is connected on the upstream side to the buffer device 323 by an air supply path 339, and on the downstream side to the output joint 327 by an air supply path 340. The switching valve 322 of this embodiment is a three-way valve having a first position that connects the storage container 50 to the buffer device 323, and a second position that connects the storage container 50 to the negative pressure supply path 332. The switching valve 322 is a pilot-operated solenoid valve that switches between the first position and the second position with the help of pilot pressure from the pilot air pressure adjusting device 313.

[0047] The buffer device 323 is similar to that in the first embodiment and is housed in a case 326. The distance between the outlet of the buffer device 323 and the top end of the storage container 50 is 200 cm or less, allowing the desired pressure to be quickly applied to the storage container 50 at the start of discharge. The adapter tube 60 has the configuration shown in FIG. 3 , and the air supply path 62 has a total length of, for example, 10 to 200 cm, preferably 20 to 150 cm, and more preferably 30 to 100 cm. By ensuring that the length of the air supply path 62 is at least a certain length, it is possible to prevent the liquid material from flowing back through the air supply path 62 and reaching the switching valve 322, which could cause a malfunction, when negative pressure is generated in the negative pressure supply path 332.

[0048] The exhaust valve 324 is an on-off valve that communicates with the atmosphere. During the dispensing operation, it is in the closed position to pressurize the upper space of the storage container 50, and when dispensing is completed, it is in the open position to quickly release the pressurized air in the upper space of the storage container 50. By providing the exhaust valve 324, it is possible to quickly stop the discharge of the liquid material from the discharge port even after dispensing is completed. The exhaust valve 324 is a pilot-operated solenoid valve that switches between the open and closed positions with the help of pilot pressure from the pilot air pressure adjusting device 313. In this embodiment, the switching valve 322 and exhaust valve 324 provided in the switching device 320 constitute the discharge valve. The configuration of the discharge valve is not limited to the illustrated configuration. For example, it may be configured by combining multiple solenoid valves such as on-off valves or switching valves, or the switching valve and exhaust valve may be configured as a single valve device such as a multi-way valve.

[0049] The pressure sensor 325 measures the pressure value in the air supply path 340 and transmits it to the second control device 321. The second control device 321 includes a processing device (not shown) and a storage device (not shown) storing a sub-control program. The second control device 321 controls the operation of the switching valve 322 and the exhaust valve 324 as needed based on the measurement value of the pressure sensor 325. The first control device 311 also controls the operation of the first pressurized air pressure regulator 312, the pilot air pressure regulator 313, and the second pressurized air pressure regulator 314 as needed based on the measurement value of the pressure sensor 325 received from the second control device 321. In this embodiment, the pressure sensor 325 is provided in the switching device 320, which is closer to the storage container 50, rather than in the main device 310. This allows the pressure at a position closer to the storage container to be acquired and controlled, thereby enabling the pressure of the pressurized air in the storage container 50 to be controlled to a more appropriate value. In addition, the second control device 321 may have some or all of the functions of the first control device 311, or the first control device may have some or all of the functions of the second control device 321.

[0050] The second control device 321 can also perform control based on measurements from sensors other than a pressure sensor. For example, it can be equipped with a temperature control function that controls a temperature regulator that adjusts the temperature of the storage container 50 based on a signal from a temperature sensor provided in the storage container 50, and a remaining amount detection function that detects the remaining amount of liquid material in the storage container 50 based on a signal from a liquid amount detection sensor provided in the storage container 50.

[0051] The liquid material discharging device 100 of the third embodiment described above has good responsiveness to air pressure control at the start and end of discharging because the storage container 50 and the buffer device 323 are located close to each other. In addition, the provision of the exhaust valve 324 allows the pressure in the storage container 50 to be quickly released, making it possible to quickly stop discharging of the liquid material from the discharge port.

[0052] Furthermore, since a negative pressure can be generated in the storage container 50 via the negative pressure supply path 332, it is possible to solve the problem of liquid dripping from the discharge port when not discharging. In this embodiment, the negative pressure air supply device is configured by the second pressurized air pressure adjusting device 314 and the ejector 315, but the negative pressure air supply device may be configured by another device as long as it can supply a negative pressure that can prevent liquid dripping from the discharge port when not discharging.

[0053] In addition, although this embodiment has both the function of exhausting air and generating negative pressure, a configuration having only one of these functions is also possible. Furthermore, by controlling the operation of the various valve devices based on the measurement value of the pressure sensor 325, it is possible to obtain and control the pressure at a position close to the storage container, so it is possible to control the pressure of the pressurized air in the storage container 50 to a more appropriate value.

[0054] 10 is different from the liquid material discharge device 100 of the third embodiment in that the buffer device 423 is not housed in the case 426. The following description will focus on the differences from the third embodiment, and common features will be given the same reference numerals as in the third embodiment, and description thereof will be omitted.

[0055] The main unit 310 has the same configuration as in the third embodiment, so its description will be omitted. The switching device 420 includes a second control device 421, a switching valve 422, an exhaust valve 424, a pressure sensor 425, and a case 426. In this embodiment, the switching valve 422 and exhaust valve 424 included in the switching device 420 constitute a discharge valve. The second control device 421, the switching valve 422, the exhaust valve 424, and the pressure sensor 425 have the same configurations as in the third embodiment, so their description will be omitted. The configuration of the discharge valve is not limited to the illustrated configuration. For example, it may be configured by combining multiple electromagnetic valves such as on-off valves or switching valves, or the switching valve and exhaust valve may be configured as a single valve device such as a multi-way valve. The air supply path and negative pressure supply path provided inside the switching device 420 may be configured by flexible or non-flexible piping, or may be configured by flow paths formed in a block.

[0056] The case 426 does not have a buffer device 423 disposed therein, and therefore has a smaller volume than the case 326 of the third embodiment. In FIG. 10 , the buffer device 423 and the case 426 are depicted as being separated from each other, but as in the second embodiment, the buffer device 423 is attached to the case 426 by an attachment (mounting fixture) or the like (not shown). The output port of the buffer device 423 is connected to the switching valve 422 via a third air supply path 439. The total length of the third air supply path 439 is 50 cm or less, preferably 40 cm or less, and more preferably 30 cm or less.

[0057] 11 is a perspective view showing a liquid material discharging device 110 of the fourth embodiment. The switching device 420 has an output joint 427 provided at the bottom of the front side of a case 426, and a buffer device 423 attached to the top of the rear side of the case 426. A signal cable 331, a negative pressure supply path 332, and a pilot pipe 335 are connected to the bottom of the rear side of the case 426, all of which are flexible. A flexible second air supply path 334 is connected to the top surface of the buffer device 423.

[0058] In the liquid material discharging device 110 of the fourth embodiment described above, the storage container 50 and the buffer device 423 are located close to each other, so the responsiveness of the air pressure control at the start and end of discharging is good. Furthermore, the size of the buffer device 423 is not limited by the size of the case 426, so the buffer device 423 can have a large capacity. The buffer device 423 can be composed of multiple tanks, and in this case, some of the tanks may be located inside the case 426 and the remaining tanks may be located outside the case 426.

[0059] Fifth Embodiment A liquid material discharging device 500 according to the fifth embodiment includes a main device 510 and a switching device 520. The liquid material discharging device 500 according to the fifth embodiment can be mounted on a tabletop robot as exemplified in Figures 4 and 7, but can also be mounted on a large robot as exemplified in Figure 12. As shown in Figure 12, a coating device 501 on which the liquid material discharging device 500 according to the fifth embodiment is mounted is a floor-mounted robot mainly including a base 541, relative drive devices (542 to 544), a movable head 545, a work table 546, and a cover 547.

[0060] The main unit 510 of this embodiment is disposed inside the stand 541 so that the operation unit is exposed. The main unit 510 has the same configuration as the main unit 10 of the first embodiment, and therefore a description thereof will be omitted. The liquid material discharging device 500 of this embodiment has the same configuration as the first embodiment at the block diagram level. The case 523 of the fifth embodiment is rectangular parallelepiped and disposed above the front of the movable head 545. The case 523 mounted on the movable head 545 has a signal cable 531 and a second air supply path 532 inserted through its upper surface, and an adapter tube 60 attached to its side surface on the front side. A Z-direction driving device 544 and a storage container 50 are disposed below the front of the movable head 45.

[0061] The relative drive device is composed of an X-direction drive device 542, a Y-direction drive device 543, and a Z-direction drive device 544. The X-direction drive device 542 has a beam member 542a that is movable in the Y direction by the Y-direction drive device 543, and can move the movable head 545 back and forth in the X direction. The movable head 545 attached to the beam member 542a is equipped with a Z-direction drive device 544 that has a holder on the lower front surface. The operation of the relative drive device is controlled by a robot controller (not shown) arranged inside the stand 541. The robot controller is connected to the main unit 510 via a signal cable (not shown) and sends a discharge start command and a discharge end command to a control device (not shown) provided in the main unit 510.

[0062] When the liquid material discharging device 500 is mounted on a large robot such as the coating device 501, the signal cable 531 and second air supply path 532 of the liquid material discharging device 500 are longer than those of the first embodiment. Therefore, if a buffer device is provided in the main device 510, the responsiveness of the air pressure control will be further impaired. In contrast, in the fifth embodiment, a buffer device is provided in the switching device 520, so the responsiveness of the air pressure control at the start and end of discharging is good. Furthermore, the signal cable 531 and the second air supply path 532 are both flexible and are movably inserted through a cable hole 549 provided in the upper surface 548 of the base 541. Therefore, the movement of the movable head 545 is not restricted by the signal cable 531 and the second air supply path 532.

[0063] Furthermore, the signal cables and air supply paths connecting the main unit 510 and the switching unit 520 may be configured to be detachable from the main unit 510 and the switching unit 520, so that cables of various lengths can be attached. This allows the distance between the main unit 510 and the switching unit 520 to be varied, making it possible to mount the device on a wider variety of robots.

[0064] The upper surface 548 of the stand 541 on which the relative drive devices (542 to 544) and the work table 546 are mounted is covered with a cover 547 shown by a dotted line. For ease of explanation, part of the cover 547 is not depicted in FIG. 12 . By providing the cover 547, it is possible to prevent dust from adhering to the workpiece W and to prevent an operator from accidentally coming into contact with moving parts such as the relative drive devices (542 to 544). The cover 547 may be provided with an openable door to allow an operator to easily access the coating apparatus.

[0065] In the liquid material ejection device 500 of the fifth embodiment described above, the distance between the storage container 50 and the switching device 520 having the buffer device is short, so the responsiveness of the air pressure control at the start and end of ejection is good.

[0066] 12, the main unit 510 is disposed inside the stand 541, but the installation location of the main unit 510 is not limited to this, and the main unit 510 can be disposed at any position on the coating apparatus 501, such as on the stand 541 or on the cover 547. The position of the switching device 520 is also not limited to the front of the movable head 545, and the switching device 520 may be disposed on the top surface or other side surface of the movable head 545. The switching device 520 may also be disposed at a position on the beam member 542a where it does not interfere with the coating operation. In addition, instead of the liquid material discharging device 500, it is of course possible to mount the liquid material discharging devices exemplified in the first to fourth embodiments on a large robot as shown in FIG.

[0067] Although preferred embodiments and modifications of the present invention have been described above, the technical scope of the present invention is not limited to the above-described embodiments. Various modifications and improvements can be made to the above-described embodiments, and such modifications and improvements are also included in the technical scope of the present invention. For example, the present invention can also be applied to a type of robot in which a head holding a storage container communicating with a nozzle is fixed, and only the workpiece is moved relative to the nozzle by a relative drive device.

[0068] DESCRIPTION OF SYMBOLS 1: Liquid material discharge device (first embodiment) 10, 210, 310, 510: Main device 11, 211: Control device 12: Pressurized air pressure regulator 13, 316: Case 14, 333: First air supply path 20, 120, 220, 320, 420, 520: Switching device 21, 121: Discharge valve 22, 122, 323, 423: Buffer device 23, 123, 326, 426, 523: Case 24, 124, 327: Output joint 31, 131, 231, 531: Signal cable 32, 132, 232, 334, 532: Second air supply path 33: Third air supply path 34: Fourth air supply path 35, 135: Signal cable 40: Coating device (first embodiment) 41: Stand 42: X-direction drive device 43: Y-direction drive device 44: Z-direction drive device 45: Movable head 46: Work table 50: Storage container 60: Adapter tube 61: Adapter 62: Air supply path 63: Joint connector 70: Air supply source 81: X direction 82: Y direction 83: Z direction 90: Liquid material discharge device (second embodiment) 91: Coating device (second embodiment) 100: Liquid material discharge device (third embodiment) 110: Liquid material discharge device (fourth embodiment) 311: First control device 312: First pressurized air pressure regulator 313: Pilot air pressure regulator 314: Second pressurized air pressure regulator 321: Second control device 322, 422: Switching valve 324, 424: Exhaust valve 332: Negative pressure supply path 335: Pilot piping 500: Liquid material ejection device (fifth embodiment) 501: Coating device (fifth embodiment)

Claims

1. A liquid material discharging device comprising: a main unit connected to an air supply source; a switching device configured as a separate entity from the main unit and supplying air into a storage container communicating with a nozzle; and a buffer device, wherein the main unit comprises a pressurized air pressure adjusting device that adjusts the pressurized air supplied from the air supply source to a desired pressure, and a control device, the switching device comprises a discharge valve that switches between communication and blocking of a flow path connecting the pressurized air pressure adjusting device and the storage container, the main unit and the switching device are connected by an air supply path that is at least partially flexible so that their relative positions can be changed, and the buffer device is arranged within the switching device or directly or indirectly connected to the switching device.

2. The liquid material discharge device according to claim 1, wherein the total length of the flow path connecting the discharge valve and the buffer device is 50 cm or less.

3. The liquid material discharge device according to claim 1, further comprising a connector or attachment for attaching said switching device to a robot that moves said storage container relative to a workpiece.

4. The liquid material discharging device according to claim 1, characterized in that the switching device has a case that houses the discharge valve, and the buffer device includes a container provided within the case of the switching device.

5. The liquid material discharge device according to claim 1, characterized in that the switching device has a case that houses the discharge valve, and the buffer device includes a container provided outside the case of the switching device.

6. The liquid material discharging device according to claim 5, further comprising a connector or attachment for attaching the buffer device to the case.

7. The liquid material dispensing device according to claim 1, wherein the switching device comprises an output joint fluidly connected to the dispensing valve for connecting an air supply pipe to which a reservoir is connected.

8. The liquid material discharging device according to claim 1, wherein the pressurized air pressure adjusting device includes a pressure regulator.

9. The liquid material discharging device according to claim 1, wherein the discharging valve comprises at least one pilot-operated valve.

10. The liquid material discharging device according to claim 9, wherein the main device includes a pilot air pressure adjusting device that supplies a pilot pressure to the pilot valve.

11. The liquid material discharging device according to claim 10, wherein the pilot air pressure adjusting device includes a pressure regulator.

12. The liquid material discharging device according to claim 1, wherein the discharging valve is a multi-way valve.

13. The liquid material discharging device according to claim 1, wherein the discharging valve is composed of a plurality of electromagnetic valves.

14. The liquid material discharging device according to claim 1, further comprising a pressure sensor provided in a flow path connecting the storage container and the discharge valve, and the control device controls the discharge valve based on the measurement value of the pressure sensor.

15. The liquid material discharge device according to claim 1, wherein the discharge valve is capable of switching between communication between the pressurized air pressure adjusting device and the storage container and communication between the atmosphere and the storage container.

16. A liquid material discharge device as described in any one of claims 1 to 15, characterized in that the main device is equipped with a negative pressure air supply device that supplies negative pressure, the negative pressure air supply device and the discharge valve are connected by a negative pressure air supply path that is at least partially flexible, and the discharge valve is capable of switching between communication between the pressurized air pressure adjustment device and the storage container and communication between the negative pressure air supply device and the storage container.

17. The liquid material ejection device according to claim 16, wherein the negative pressure air supply device includes an ejector.

18. The liquid material ejection device according to claim 17, wherein the negative pressure air supply device includes a pressure regulator provided between the ejector and the air supply source.

19. A coating device comprising: a liquid material discharging device according to any one of claims 1 to 15; a robot having a holder for holding the storage container and for moving the holder relative to an object to be coated; and a flexible air supply pipe connecting the liquid material discharging device and the storage container.

20. The applicator of claim 19, further comprising a connector or attachment for attaching said switching device to said robot.

21. The coating device according to claim 20, wherein the connector or attachment is a connector or attachment for attaching the switching device to a movable head having the holder.

22. The coating device described in claim 20, characterized in that the robot has a beam member on which a movable head having the holder is mounted, and the connector or attachment is a connector or attachment for attaching the switching device to the beam member.

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