JP6003707B2 - Coating device - Google Patents

Description

  The present invention relates to a coating apparatus that applies a coating material to the surface of a workpiece.

  2. Description of the Related Art Conventionally, as a coating apparatus that applies a coating material to the surface of a workpiece, a material coating apparatus disclosed in Patent Document 1 below is known. This material application device includes a plunger that advances and retreats when the material is discharged from the cylinder and when the material is supplied into the cylinder, and a gear mechanism for advancing and retreating the plunger, and an electromagnetic clutch is provided between the gear mechanism and the motor. Is provided. When the material is discharged, the gear mechanism is operated in accordance with the driving of the motor and the plunger moves forward into the cylinder, whereby the material pressurized by the plunger is discharged from the nozzle. At the time of material supply, the material is pumped into the cylinder from the material supply pump in a state where the connection between the gear mechanism and the motor is cut off by the electromagnetic clutch. At this time, the plunger is pushed up by the pumped material and the gear mechanism rotates in the reverse direction, but the reverse rotation of the motor is prevented by disconnecting the connection between the gear mechanism and the motor by the electromagnetic clutch.

JP 2009-090264 A

  By the way, when the deterioration of the sealing performance, for example, deterioration of the seal member for the plunger that moves when the coating material is supplied to the storage chamber in which the coating material is stored, the coating material into the storage chamber may depend on the internal pressure in the storage chamber. When the air is supplied, the outside air may enter the storage chamber, and bubbles may be mixed into the storage chamber. When applying a coating material in which bubbles are mixed in this way, the coating material containing bubbles may burst immediately after being discharged from the discharge port, which may cause an application abnormality in which the coating surface becomes uneven. .

  Although it is conceivable to increase the supply pressure for supplying the coating material to the storage chamber in order to suppress the mixing of bubbles into the storage chamber, it is difficult to increase the supply pressure in consideration of the pressure resistance of the material cartridge and the piping path. If a mechanism for increasing the dedicated supply pressure is employed, the manufacturing cost increases. There is also a problem that the seal member is likely to deteriorate when the supply pressure is simply increased. On the other hand, it is possible to gradually supply the coating material into the storage chamber in order to suppress the mixing of bubbles into the storage chamber, but there is another problem that the supply time of the coating material becomes longer and the working efficiency is lowered. End up.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a coating apparatus capable of suppressing the mixing of bubbles into a storage chamber in which a coating material is stored. .

In order to achieve the above-described object, the coating apparatus (10) according to claim 1 of the claims is configured such that when the coating material (90) is stored and reaches a predetermined pressure (Pn), the coating device (10) passes through the discharge port (28). A storage chamber (26) into which the coating material is discharged, supply means (30, 40) for supplying the coating material into the storage chamber, and an internal pressure adjusting means (23) capable of adjusting the internal pressure (P) in the storage chamber. And a difference between the internal pressure and the atmospheric pressure measured by the internal pressure measuring means when the coating material is supplied into the storage chamber by the supplying means and the internal pressure measuring means (60) for measuring the internal pressure. Control means (80) for controlling the internal pressure adjusting means, and the internal pressure measuring means is arranged to measure the internal pressure in the vicinity of the discharge port, and applies the discharged coating material. Abnormality is measured by the internal pressure measuring means Detection means (80) for detecting in response to fluctuations in the internal pressure, and a predetermined first pressure threshold value at which the internal pressure measured by the internal pressure measurement means is smaller than the predetermined pressure when the coating agent is discharged. The application abnormality is notified when it is equal to or less than (Pn1) or when it is equal to or greater than a predetermined second pressure threshold (Pn2) greater than the predetermined pressure .
In addition, the code | symbol in the parenthesis of a claim and the said means shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  In the first aspect of the invention, the internal pressure adjusting means is controlled by the control means so that the difference between the internal pressure measured by the internal pressure measuring means and the atmospheric pressure becomes small when the coating material is supplied into the storage chamber by the supply means. . Accordingly, when the coating material is supplied into the storage chamber, the difference between the internal pressure in the storage chamber and the atmospheric pressure becomes small, so that the internal pressure in the storage chamber becomes a large negative pressure even temporarily due to the operation of the excessive internal pressure adjusting means. Compared to the case, the outside air is less likely to enter the storage chamber. Therefore, it is possible to suppress the mixing of bubbles into the storage chamber in which the coating material is stored without reducing the work efficiency.

It is explanatory drawing which shows schematic structure of the coating device which concerns on this embodiment. It is a block diagram which shows roughly the electrical structure of a coating device. It is sectional drawing which shows roughly the discharge outlet vicinity of a plunger pump. It is explanatory drawing which shows the relationship between the time change of the internal pressure in a suction step, a standby step, and a discharge step, and the movement of a plunger. It is explanatory drawing which shows the time change of the suction speed and internal pressure in a suction step. It is explanatory drawing which shows the relationship between the discharge command timing in the state from which an internal pressure varies in a waiting | standby step, and an actual discharge timing. It is explanatory drawing which shows the relationship between the discharge command timing and the actual discharge timing in the state in which the internal pressure was maintained at the discharge standby pressure in the standby step. It is explanatory drawing which shows the time change of the internal pressure in a discharge step.

Hereinafter, an embodiment in which a coating apparatus of the present invention is embodied will be described with reference to the drawings.
A coating apparatus 10 shown in FIG. 1 is an apparatus for applying a coating material 90 such as a heat radiating gel or a sealing material to a workpiece 91 such as a substrate. The coating apparatus 10 mainly includes a plunger pump 20, a supply tank 30, a supply valve 40, a needle 50, a pressure sensor 60, a moving mechanism 70, and a controller 80.

  The plunger pump 20 is a pump for discharging the coating material 90 to the workpiece 91, and includes a cylinder 21, a plunger 22 that reciprocates in the cylinder 21, and a plunger 22 in its axial direction (vertical direction in FIG. 1). And a servo mechanism 23 that reciprocates. As shown in FIG. 2, the servo mechanism 23 is configured to be driven and controlled via the servo driver 24 in accordance with a drive command from the controller 80. Moreover, the plunger 22 slides on the inner peripheral wall surface of the cylinder 21 via the seal member 25 assembled to the outer periphery of the tip portion 22a during the reciprocating motion.

  For this reason, the pump chamber 26 is defined by the inner peripheral wall surface of the cylinder 21 and the tip 22 a of the plunger 22. The pump chamber 26 constitutes a storage chamber in which the coating material 90 is stored, and its volume varies according to the reciprocation of the plunger 22 by the servo mechanism 23. In the pump chamber 26, a supply port 27 for supplying the coating material 90 and a discharge port 28 for discharging the coating material 90 are formed. The servo mechanism 23 may correspond to an example of “internal pressure adjusting means” recited in the claims.

  The supply tank 30 and the supply valve 40 are supply means for supplying the coating material 90 to the plunger pump 20, and a predetermined amount of the coating material 90 to be supplied to the plunger pump 20 is stored in the supply tank 30. The supply tank 30 communicates with the supply port 27 of the pump chamber 26 via a supply pipe 41 provided with a supply valve 40. Further, pressurizing air for generating a supply pressure is sent into the supply tank 30 through a pipe (not shown). When the supply valve 40 is opened while the coating material 90 is pressurized with the pressurizing air, the supply of the coating material 90 in the supply tank 30 to the pump chamber 26 is started.

  In addition, in this embodiment, since the pressure for supply is generated, the air for pressurization also used for other production lines is sent to the supply tank 30 for pressurization. The supply pressure may be generated by adopting another means for generating the pressure, for example, a dedicated pressurizing device. In this case, the supply pressure can be generated constantly or at a necessary timing by the other means. The open / closed state of the supply valve 40 may be controlled by the controller 80 or may be controlled by another controller or the like. Further, the opening degree of the supply valve 40 may be controlled in order to control the supply pressure of the coating material 90 to the pump chamber 26.

FIG. 3 is a cross-sectional view schematically showing the vicinity of the discharge port 28 of the plunger pump 20.
As shown in FIG. 3, the needle 50 is always urged by a needle spring 51 so as to close the discharge port 28. For this reason, when the internal pressure P in the pump chamber 26 reaches the needle operating pressure Pn exceeding the biasing pressure Pt by the needle spring 51, the needle 50 counteracts the biasing force of the needle spring 51 (downward direction in FIG. 3). The discharge port 28 is opened. The needle operating pressure Pn may correspond to an example of “predetermined pressure” described in the claims.

  The pressure sensor 60 is an internal pressure measuring unit that measures the difference between the pressure in the pump chamber 26 and the atmospheric pressure as the internal pressure P, and is a plunger pump that outputs a pressure signal corresponding to the internal pressure P in the vicinity of the discharge port 28. 20 is attached. The pressure signal output from the pressure sensor 60 according to the internal pressure P is amplified by the sensor amplifier 61 and input to the controller 80 (see FIG. 2).

  The moving mechanism 70 is a mechanism for moving the workpiece 91 relative to the plunger pump 20, and a mounting table 71 on which a jig 92 that holds the workpiece 91 is mounted, and the mounting table 71 as X, Y. Moving axes 72 and 73 for moving in the direction are provided. Servo motors provided on the moving shafts 72 and 73 are configured to be driven and controlled via a servo driver 74 in accordance with a drive command from the controller 80 (see FIG. 2).

  For this reason, the mounting table 71 on which the jig 92 holding the workpiece 91 is mounted moves in the horizontal direction according to the driving of the moving shafts 72 and 73 under the control of the servo motor, so that the workpiece 91 and the jig 91 are fixed. The tool 92 moves relative to the plunger pump 20. The moving mechanism 70 is not limited to being configured to move the mounting table 71 in the X and Y directions in two axes, but is configured to move the mounting table 71 in the three axes in the X, Y, and Z directions. May be.

  The controller 80 is a control unit that controls the overall control of the coating apparatus 10 and is configured by a known microcomputer including a CPU, a ROM, a RAM, an I / O, and the like. The controller 80 functions to control the discharge / suction state of the plunger pump 20 according to the internal pressure P or the like measured by the pressure sensor 60 by executing a coating process described later.

  Next, a coating process in which the coating material 90 is coated on the work 91 by the coating apparatus 10 configured as described above will be described below. 4 is an explanatory view showing the relationship between the change in the internal pressure P over time and the movement of the plunger 22 in the suction step, the standby step and the discharge step, and FIG. 4 (A) shows the change over time in the internal pressure P. 4 (B) shows the movement state of the plunger 22. FIG. 5 is an explanatory diagram showing the time change of the suction speed V and the internal pressure P in the suction step, FIG. 5 (A) shows the time change of the suction speed V, and FIG. 5 (B) shows the time of the internal pressure P. Showing change. FIG. 6 is an explanatory diagram showing the relationship between the discharge command timing ta and the actual discharge timing when the internal pressure P varies in the standby step. FIG. 7 is an explanatory diagram showing the relationship between the discharge command timing ta and the actual discharge timing in a state where the internal pressure P is maintained at the discharge standby pressure P4 in the standby step. FIGS. 8A to 8E are explanatory views showing temporal changes in the internal pressure P in the discharge step.

  In the coating process executed by controlling the plunger pump 20 and the like by the controller 80, a suction step in which the coating material 90 is sucked into the plunger pump 20, a standby step for waiting until the discharge timing, and the coating material 90 from the plunger pump 20 The three steps shown in FIGS. 4 (A) and 4 (B) are sequentially repeated. In FIG. 4B, the movement of the plunger 22 driven by the servo mechanism 23 in the axial direction is indicated by X, the negative side indicates the movement in the suction direction, and the positive side indicates the movement in the discharge direction.

First, the suction step will be described below.
When the suction step is started, the supply valve 40 is opened, so that the application material 90 stored in the supply tank 30 can be supplied to the pump chamber 26. In this state, when the plunger 22 moves in the suction direction (upward in FIG. 1), the internal pressure P in the pump chamber 26 decreases, and the coating material 90 in the supply tank 30 corresponds to the decrease in the internal pressure P. Is sucked into the pump chamber 26 of the plunger pump 20.

  The internal pressure P changes according to the moving speed of the plunger 22 (the amount of movement of the plunger 22). For this reason, in the present embodiment, the servo mechanism 23 is feedback-controlled by the controller 80 so that the internal pressure P measured by the pressure sensor 60 becomes small. This is because by reducing the internal pressure P, the difference between the pressure in the pump chamber 26 and the atmospheric pressure becomes small, and it becomes difficult for outside air to enter the pump chamber 26.

  Specifically, in this embodiment, the moving speed in the suction direction of the plunger 22 is set as the suction speed V, and the four suction speeds V1 to V4 shown in FIG. 5 (A) and the three pressures shown in FIG. 5 (B). Threshold values P1 to P3 are prepared in advance. The controller 80 controls the servo mechanism 23 so that the suction speed V = V4 when P> P3, and controls the servo mechanism 23 so that the suction speed V = V3 when P2 <P ≦ P3. The servo mechanism 23 is controlled so that the suction speed V = V2 when P1 <P ≦ P2, and the servo mechanism 23 is controlled so that the suction speed V = V1 when P ≦ P1.

  Here, the pressure threshold value P1 is set to a value slightly larger than the atmospheric pressure. Also, the suction speed V1 is different from the other suction speeds V2 to V4, so that the internal pressure P in the pump chamber 26 slightly increases because the suction speed V is lower than the supply pressure from the supply tank 30. Is set.

  For this reason, immediately after the start of the suction step in which the supply valve 40 is opened and the movement of the plunger 22 has not yet started, the internal pressure P increases so as to exceed the pressure threshold value P3. Thereafter, the servo mechanism 23 is controlled so that the suction speed V = V4, whereby the internal pressure P decreases. When the internal pressure P becomes equal to or lower than the pressure threshold value P3 (see t1 in FIG. 5), the internal pressure P gradually decreases by controlling the servo mechanism 23 so that the suction speed V = V3. When the internal pressure P that decreases in this way becomes equal to or lower than the pressure threshold value P2 (see t2 in FIG. 5), the internal pressure P is further gradually decreased by controlling the servo mechanism 23 so that the suction speed V = V2.

  When the internal pressure P thus decreased becomes equal to or lower than the pressure threshold value P1 (see t3 in FIG. 5), the servo mechanism 23 is controlled so that the suction speed V = V1. To rise. When the rising internal pressure P exceeds the pressure threshold value P1 (see t4 in FIG. 5), the servo mechanism 23 is controlled so that the suction speed V = V2, whereby the internal pressure P decreases. That is, the servo mechanism 23 is feedback-controlled so that the internal pressure P approaches the pressure threshold value P1 until the coating material 90 sucked (supplied) into the pump chamber 26 reaches a predetermined amount.

Next, the standby step will be described below.
When the coating material 90 sucked (supplied) into the pump chamber 26 in the suction step reaches a predetermined amount, the supply valve 40 is closed and a standby step is started. In this step, the internal pressure P remains in a predetermined state until the timing for outputting a command for discharging the coating material 90 from the discharge port 28 of the plunger pump 20 to the servo mechanism 23 (hereinafter also referred to as a discharge command timing ta). The servo mechanism 23 is feedback controlled so as to be maintained.

  Specifically, when the standby step is started and the supply valve 40 is closed and the plunger 22 stops moving in the suction direction, the internal pressure P that has been controlled to approach the pressure threshold value P1 increases. The internal pressure P thus increased is adjusted so as to approach the discharge standby pressure P4 set slightly smaller than the needle operating pressure Pn by feedback control of the servo mechanism 23 immediately before the discharge.

The reason why the internal pressure P immediately before the discharge is maintained at the discharge standby pressure P4 will be described with reference to FIGS.
The internal pressure P rises from the pressure threshold P1 when the standby step is started and the supply valve 40 is closed and the movement of the plunger 22 in the suction direction stops, but this pressure rise value may vary (FIGS. 6 and 6). 7 ΔP). The higher the pressure increase value, the shorter the time difference between the discharge command timing ta and the timing at which the coating material 90 is actually discharged when the internal pressure P exceeds the needle operating pressure Pn (hereinafter also referred to as actual discharge timing). There is also a variation in responsiveness after the discharge command timing ta (see α in FIG. 6), and the time difference between the discharge command timing ta and the actual discharge timing may vary even from the same internal pressure.

  Then, as shown in FIG. 6, the actual discharge timing (see tb1 in FIG. 6) when the pressure increase value is relatively high and the response is relatively high, and the pressure increase value are relatively low and the response is compared. A large time difference occurs (see Δtb in FIG. 6) at the actual discharge timing (see tb2 in FIG. 6) when the target is low. When the actual discharge timing varies in this manner, the discharge amount of the coating material 90 varies, and an application abnormality may occur.

  Therefore, in the present embodiment, in order to suppress variation in actual discharge timing, the internal pressure P is set to the discharge standby pressure immediately before discharge, specifically, a predetermined time before the discharge command timing ta (see Δta in FIG. 7). The servo mechanism 23 is feedback controlled so as to approach P4. As a result, as shown in FIG. 7, even if the pressure increase value fluctuates, the internal pressure P is maintained at the discharge standby pressure P4 before a predetermined time before the discharge command timing ta. The variation in the actual discharge timing can be suppressed (see Δtb in FIG. 7). In particular, the discharge standby pressure P4 at which the internal pressure P is maintained is set to be slightly smaller than the needle operating pressure Pn, and therefore there is a variation in actual discharge timing due to a variation in responsiveness after the discharge command timing ta. Can be suppressed.

Next, the discharge step will be described below.
When the discharge command timing ta is reached in the standby step, the servo mechanism 23 is feedback-controlled so that the internal pressure P is maintained at the needle operating pressure Pn, and the plunger 22 moves in the discharge direction (downward in FIG. 1). The discharge step is started. In this step, the needle 50 moves in the counter-biasing direction against the urging force of the needle spring 51 in accordance with the internal pressure P, and the discharge port 28 is opened, so that the coating material 90 has the internal pressure P, that is, from the opening portion. According to the movement of the plunger 22 in the discharge direction, the plunger 22 is discharged without interruption. In this discharge state, the workpiece 91 is moved relative to the plunger pump 20 in accordance with the movement of the mounting table 71, whereby the coating material 90 is applied to a predetermined position of the workpiece 91.

  Then, when a predetermined amount of the coating material 90 is discharged without the internal pressure P greatly fluctuating, the discharging step ends, and the suction step for sucking the coating material 90 in the supply tank 30 into the pump chamber 26 of the plunger pump 20 is performed again. Be started.

  In the discharge step, as shown in FIG. 8, when the coating material 90 mixed with bubbles is applied because the bubbles are contained in the pump chamber 26, the coating material 90 containing the bubbles is discharged from the discharge port 28. Since it bursts immediately after being discharged (see FIG. 8C), the internal pressure P measured by the pressure sensor 60 varies greatly. Thus, when the coating material 90 just after discharge bursts, there is a possibility that a coating abnormality may occur in which the coating state of the coating material 90 on the coating surface of the work 91 becomes uneven.

  Therefore, in the discharge step, the internal pressure P is monitored by the controller 80, the two pressure thresholds Pn1, Pn2 set with reference to the needle operating pressure Pn are compared with the internal pressure P, and the internal pressure P falls below the pressure threshold Pn1. If the internal pressure P is equal to or higher than the pressure threshold value Pn2, it is determined that an application abnormality has occurred, and the detection result is transmitted to a higher external device to be notified. Thereby, the workpiece | work 91 with high possibility of an application | coating abnormality is easily detectable. The controller 80 may correspond to an example of “detecting means” recited in the claims.

  As described above, in the coating apparatus 10 according to this embodiment, the internal pressure P and the atmospheric pressure measured by the pressure sensor 60 when the coating material 90 is supplied into the pump chamber 26 by the supply tank 30 and the supply valve 40. The servo mechanism 23 is controlled by the controller 80 so as to reduce the difference between the two.

  Thereby, when the coating material 90 is supplied into the pump chamber 26, the difference between the internal pressure P in the pump chamber 26 and the atmospheric pressure becomes small, and therefore the internal pressure P in the pump chamber 26 is increased by the excessive operation of the servo mechanism 23. Compared to a case where a large negative pressure is generated even temporarily, the outside air is less likely to enter the pump chamber 26. Therefore, it is possible to suppress the mixing of bubbles into the pump chamber 26 in which the coating material 90 is stored without reducing the work efficiency.

  In particular, the pressure sensor 60 is arranged to measure the internal pressure P in the vicinity of the discharge port 28 of the plunger pump 20, and in the discharge step, the controller 80 detects that the application abnormality of the discharged coating material 90 has occurred. It is detected according to the fluctuation of the internal pressure P measured by

  As a result, not only can air bubbles be prevented from entering the pump chamber 26, but also the seal member 25 and the like are extremely deteriorated in sealing performance, and forgetting to throw away when replacing the cartridge for supplying the coating material 90 to the supply tank 30. Even if air bubbles are mixed into the pump chamber 26 due to the above, an application abnormality can be easily detected. In particular, since a dedicated detection device such as an image processing device for detecting an application abnormality is not required, the manufacturing cost can be reduced.

  Further, in the standby step, the servo mechanism 23 is controlled by the controller 80 so that the internal pressure P immediately before the discharge is maintained at the discharge standby pressure P4 set slightly smaller than the needle operating pressure Pn.

  As a result, the variation in the internal pressure P immediately after the start of the standby step and the variation in the actual discharge timing due to the variation in the responsiveness after the discharge command timing ta are suppressed, and the occurrence of the application abnormality can be suppressed. .

In addition, this invention is not limited to the said embodiment, For example, you may actualize as follows.
(1) The present invention is not limited to being applied to a coating device that applies a coating material such as a heat-dissipating gel or a sealing material to a workpiece such as a substrate. For example, a coating device that applies an adhesive to a workpiece, You may employ | adopt for the coating device by which the coating material in the said storage chamber is discharged according to the internal pressure in the storage chamber in which a coating material is stored.

(2) The internal pressure adjusting means that can adjust the internal pressure P in the storage chamber (pump chamber 26) is not limited to the servo mechanism 23, and other internal pressure adjusting means such as an actuator may be used. Further, the internal pressure adjusting means such as the servo mechanism 23 is not limited to being controlled according to the four stages of suction amounts (suction speed V) as shown in FIG. 5, but is controlled according to other multi-stage suction amounts. Alternatively, the internal pressure P may be linearly controlled so as to approach the pressure threshold value P1.

DESCRIPTION OF SYMBOLS 10 ... Coating apparatus 20 ... Plunger pump 21 ... Cylinder 22 ... Plunger 23 ... Servo mechanism (internal pressure adjustment means)
26 ... Pump room (storage room)
28 ... Discharge port 30 ... Supply tank (supply means)
40 ... Supply valve (supply means)
60 ... Pressure sensor (internal pressure measuring means)
80 ... Controller (control means, detection means)
90 ... Coating material P ... Internal pressure Pn ... Needle working pressure (predetermined pressure)

Claims (2)

When the coating material (90) is stored and reaches a predetermined pressure (Pn), a storage chamber (26) in which the coating material is discharged through the discharge port (28);
Supply means (30, 40) for supplying the coating material into the storage chamber;
An internal pressure adjusting means (23) capable of adjusting the internal pressure (P) in the storage chamber;
An internal pressure measuring means (60) for measuring the internal pressure;
Control means (80) for controlling the internal pressure adjusting means so that a difference between the internal pressure measured by the internal pressure measuring means and the atmospheric pressure is reduced when the coating material is supplied into the storage chamber by the supply means; ,
Equipped with a,
The internal pressure measuring means is arranged to measure the internal pressure in the vicinity of the discharge port,
A detection means (80) for detecting an abnormal application of the discharged coating material in accordance with a variation in the internal pressure measured by the internal pressure measurement means;
When the coating agent is discharged, the internal pressure measured by the internal pressure measuring means is equal to or lower than a predetermined first pressure threshold (Pn1) smaller than the predetermined pressure, or a predetermined first pressure larger than the predetermined pressure. When the pressure threshold value (Pn2) is 2 or more, the application apparatus is notified as the application abnormality . The said control means controls the said internal pressure adjustment means so that the said internal pressure just before discharge may be maintained at the pressure (P4) set so that it may become slightly smaller than the said predetermined pressure. 2. The coating apparatus according to 1.

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