JP4969912B2 - Screen printing machine - Google Patents

Description

  The present invention relates to a screen printing machine that applies a solder paste to a printed circuit board through a mask sheet and includes a cleaning device that removes the solder paste attached to the mask sheet.

  2. Description of the Related Art Conventionally, various types of screen printers that apply solder paste to a printed circuit board through a mask sheet are equipped with a cleaning device that removes solder paste adhered to the mask sheet after printing.

For example, in the screen printing machine disclosed in Patent Document 1, a cleaning unit equipped with a cleaning tape is disposed below a mask sheet installation location, a tank for storing cleaning liquid, and a cleaning liquid in the tank are used. A supply pipe for supplying the cleaning tape and a pump provided in the middle of the supply pipe are provided, and the cleaning liquid is supplied to the cleaning tape by driving the pump. Then, with the cleaning tape impregnated with the cleaning liquid in contact with the lower surface of the mask sheet, the cleaning unit moves along the lower surface of the mask sheet, so that the solder paste attached to the mask sheet is wiped off by the cleaning tape. It becomes like this.
JP 2006-7462 A

  As the cleaning liquid, a volatile liquid may be used. When such a cleaning liquid is used, since the cleaning liquid evaporates from the tip of the supply pipe in small amounts, the cleaning liquid in the supply pipe decreases with time. For this reason, for example, when the night printing machine is stopped, the cleaning liquid in the tip of the supply pipe disappears, and the cleaning liquid may not be supplied to the cleaning tape in the initial cleaning after restarting the next day. If the supply pipe is cracked, the cleaning liquid does not flow out from the tip of the supply pipe even when the pump is driven, and there is a possibility that the cleaning liquid cannot be supplied to the cleaning tape.

  In view of such circumstances, an object of the present invention is to provide a screen printing machine capable of supplying a cleaning liquid to a cleaning tape so that there is no shortage.

In order to solve the above-mentioned problems, the present invention provides a screen printing machine including a cleaning unit that contacts a lower surface of a mask sheet with a cleaning tape impregnated with a cleaning liquid and wipes off a solder paste attached to the mask sheet. A tank for storing cleaning liquid, a discharge pipe for the cleaning liquid, a supply pipe for supplying the cleaning liquid in the tank to the cleaning tape, a pump provided in the middle of the supply pipe, and driving of the pump And a cleaning liquid detection means for detecting the presence or absence of the cleaning liquid in the supply pipe at a position downstream of the pump and in the vicinity of the discharge port. and which, the control unit, the washing liquid detection means starts driving of the pump in a state in which detected the absence wash cleaning liquid sensing hand After detecting that there is no cleaning liquid, either stop driving the pump after driving the pump for a predetermined time, or after detecting that the cleaning liquid detection means changes from the presence or absence of cleaning liquid, It starts driving, after the start of driving of the pump and is characterized that you implement at least one of either stopping the driving of the pump after driving for a predetermined time pumps.

According to this configuration, the cleaning liquid sensing means are provided downstream of the pump in the supply pipe, driving a predetermined time pumps the washing liquid detection means from detecting the change without color there changes or cleaning fluid there from without cleaning solution since the so that is, it is possible to control the amount of the pump driving time of the cleaning liquid flowing out of the supply pipe, it is possible to reduce the amount of washing liquid up unnecessary. Therefore, so wear washings supply the cleaning tape while suppressing consumption of the cleaning liquid. In addition, even if the pump is driven in a state where the cleaning liquid detection means detects the absence of the cleaning liquid, if the cleaning liquid detection means does not detect the change from the absence of the cleaning liquid to the presence, etc. Since an abnormality can be detected, it is possible to perform maintenance quickly even when an abnormality occurs, and it is possible to prevent the cleaning liquid from being supplied to the cleaning tape due to the abnormality. Therefore, it becomes possible to supply the cleaning liquid to the cleaning tape so that there is no shortage. Further, since the distance between the discharge port and the cleaning liquid detection means is short, the amount of extra cleaning liquid consumed is small, and the consumption of the cleaning liquid can be further suppressed.

Note that when the predetermined time is the first predetermined time, the control unit changes the cleaning liquid detection means from the presence of the cleaning liquid to the absence of the cleaning liquid within the second predetermined time after stopping the driving of the pump. When the pump is started in a state where the cleaning liquid detection means detects the absence of the cleaning liquid, the cleaning liquid detection means is started within a third predetermined time. It is preferable that a warning is given to the user when no change is detected from being absent to being present.

  According to this configuration, it is possible to notify the user of an abnormality such as a crack in the supply pipe.

  Further, the discharge port of the supply pipe is located below the cleaning tape, and the supply pipe extends in a substantially vertical direction in the vicinity of the discharge port, and is formed in a portion extending in the substantially vertical direction. It is preferable that the cleaning liquid detection means is provided.

  According to this configuration, the speed at which the liquid level of the cleaning liquid gradually decreases after the pump driving is stopped is extremely slow in the case of evaporation, but is relatively fast in the case of leakage. Depending on the time until it is detected that there is no cleaning liquid in the supply pipe, it can be determined whether the cause of the decrease in the cleaning liquid is evaporation or leakage.

  Further, the tank is provided with a liquid level detecting means for detecting the liquid level height of the cleaning liquid in the tank, and the controller detects that the liquid level height detected by the liquid level detecting means is a predetermined value. If it is less, it is preferable to warn the user.

  According to this configuration, since a warning is given when the amount of the cleaning liquid in the tank is small, the user can quickly replenish the tank with the cleaning liquid.

  The cleaning unit is movable along the lower surface of the mask sheet, while the tank is fixedly provided, and one end of the supply pipe is fixed to the cleaning unit, It is preferable that the other end of the pipe is connected to the tank, and a portion other than the other end of the supply pipe is constituted by a flexible hose.

  In this way, it is possible to reduce the weight of the movable cleaning unit.

  According to the present invention, the cleaning liquid can be supplied to the cleaning tape so as not to be insufficient.

  Embodiments of the present invention will be described with reference to the drawings.

  1 and 2 schematically show a screen printing machine according to an embodiment of the present invention. FIG. 1 is a side view and FIG. 2 is a front view showing the screen printing machine.

  As shown in these drawings, a printing stage 10 is provided on a base 2 in a printing machine housing 1, and a printed board W is carried into and out of the printing stage 10 on both sides of the printing stage 10. Therefore, an upstream conveyor 11 and a downstream conveyor 12 are arranged along the X-axis direction (conveyance line).

  Further, the printing machine includes a clamp unit 3 for clamping the printed circuit board W, a positioning unit 4 for engaging and positioning the upper surface of the substrate W when clamping the substrate W, and an upper part of the printing stage 10. A mask sheet holding unit 5 and a squeegee unit 6, a camera unit 7 for photographing the substrate W and the mask sheet 51 (see FIGS. 3 and 4), and a solder paste attached to the mask sheet 51. The substrate W clamped by the clamp unit 3 is placed on the mask sheet 51 of the mask sheet holding unit 5 and screen printing is performed by the squeegee 61 of the squeegee unit 6 in this state. It has come to be.

  The printing stage 10 includes a Y-axis table 21, an X-axis table 22, an R-axis table 23, and an elevating table 24, and the substrate W is placed horizontally and the X-axis, Y-axis, Z-axis, and R-axis (around the Z-axis) It is designed to be displaceable in the direction of rotation.

  That is, a rail 211 is arranged on the base 2 along a Y-axis direction orthogonal to the X-axis in a horizontal plane, and a Y-axis table 21 is slidably attached to the rail 211 in the Y-axis direction. The Y-axis table 21 is driven via a ball screw mechanism by an external Y-axis servo motor. An X-axis table 22 is slidably mounted on the Y-axis table 21 in the X-axis direction, and the X-axis table 22 is driven via a ball screw mechanism by an X-axis servo motor (not shown). Yes. In addition, an R-axis table 23 is mounted on the X-axis table 22 so as to be rotatable about a vertical line (Z-axis direction), and the R-axis table 23 is rotated by a non-illustrated R-axis servo motor via a ball screw mechanism. It is designed to be driven. Further, an elevating table 24 is mounted on the R-axis table 23 so as to be movable up and down, and the elevating table 24 is driven up and down via a ball screw mechanism by a Z-axis servo motor (not shown).

  A pair of main conveyors 20 is provided on the lifting table 24 along the X-axis direction. The main conveyor 20 is arranged with the upstream end and the downstream end facing the end of the upstream conveyor 11 and the end of the downstream conveyor 12 in a state where the elevating table 24 is lowered, In this state, the substrate W can be transferred between the main conveyor 20 and the conveyors 11 and 12 on both sides.

  A mounting table 29 is provided between the pair of main conveyors 20 on the lifting table 24 so as to be vertically movable via a slide column 291. A ball screw mechanism (not shown) is provided between the mounting table 29 and the lifting table 24, and the mounting table 29 moves in the vertical direction with respect to the table 24 by driving the ball screw mechanism. It is configured as follows. The placement table 29 is for allowing the substrate W to be placed. When the placement table 29 is raised, the substrate W on the main conveyor 20 is transferred onto the placement table 29 and moved upward, while it is lowered. Thus, the substrate W on the placement table 29 is configured to be transferred to the main conveyor 20 side.

  The clamp unit 3 provided on the lifting table 24 includes a pair of strip-shaped clamp pieces 31a and 31b arranged along the X-axis direction above the pair of main conveyors 20, and one of the clamp pieces 31a is The other side clamp piece 31b is fixed to the lifting table 24, and the other side clamp piece 31b is slidable in the Y-axis direction so as to be able to contact and separate from the one side clamp piece 31a. When the placement table 29 on which the substrate W is placed rises, the other side clamp piece 31b is driven by a driving means (not shown) and moves in a direction approaching the one side clamp piece 31a. The substrates 31a and 31b are clamped by sandwiching the substrate W from both sides.

  Further, the positioning unit 4 includes a pair of belt-like positioning plates 41a and 41b arranged corresponding to the clamp pieces 31a and 31b, respectively. Then, the positioning plates 41a and 41b are disposed on the clamp pieces 31a and 31b with the retracted positions arranged outside the clamp pieces 31a and 31b while maintaining the horizontal posture by the drive mechanism including the parallel link mechanism and the like. Thus, the positioning plate 41a, 41b is set to the positioning position when the mounting table 29 on which the substrate W is placed is lifted so that it can be displaced to the positioning position protruding inward from the clamp pieces 31a, 31b. The substrate W is positioned in contact with the substrate W.

  FIG. 3 is a perspective view showing the positional relationship of each part of the printing press.

  As shown in the figure, the mask sheet holding unit 5 has a mask sheet support base 52 fixedly provided on both the left and right sides above the printing stage 10, and a paste application portion is provided on the mask sheet support base 52. The mask sheet 51 having an opening is placed in a state where the mask sheet 51 projects in a horizontal arrangement. Two mask sheet clamps 53 are provided on the left and right mask sheet support bases 52 on the front and rear sides, respectively, and the mask sheet clamps 53 are driven by a driving means (not shown) such as an air cylinder. Is fixed on the mask sheet support base 52.

  The squeegee unit 6 provided on the upper side of the mask sheet holding unit 5 is supported by a squeegee support frame 63 erected on both the left and right sides of the printing stage 10. Guide rails 64 extending in the Y-axis direction are provided on the upper surfaces of the left and right squeegee support frames 63, and a movable beam 65 movable along the guide rails 64 is provided so as to straddle the upper side of the printing stage 10. A pair of squeegees 61 are attached to the beam 65 so as to be movable up and down.

  FIG. 4 is a perspective view showing a portion in which the camera unit and the cleaning unit of the cleaning device are incorporated in the screen printing machine of the present embodiment.

  As shown in FIGS. 3 and 4, on the left and right sides of the printing stage 10, lower guide rails 74 extending in the Y-axis direction are provided on the lower surface side of the squeegee support frame 63. A moving beam 75 is supported so as to be stretched. The moving beam 75 is movable in the Y-axis direction along the lower guide rail 74, and the height position thereof is set between the printing stage 10 in the lowered state and the mask sheet 51.

  A ball screw 76 is provided outside the squeegee support frame 63 along the Y-axis direction, and a nut (not shown) provided on the moving beam 75 is screwed to the ball screw 76. The moving beam 75 is moved in the Y-axis direction by being driven to rotate.

  A camera unit 7 for photographing the substrate W and the mask sheet 51 and a cleaning unit 80 of the cleaning device 8 are attached to the moving beam 75. Thus, in this embodiment, the moving beam 75 is shared as a moving mechanism for the camera unit 7 and the cleaning unit 80. Further, the lower guide rail 74 that supports the moving beam 75 is provided from the printing work area below the mask sheet 51 to the rear thereof. When the printing work is executed, the camera unit 7 and the cleaning unit 80 are printed. By retracting to a standby position behind the work area, interference with the printing stage 10 is prevented.

  The camera unit 7 is attached in front of the moving beam 75. The camera unit 7 includes a camera head 71 including an upward-facing mask sheet photographing camera 711 and a downward-facing substrate photographing camera 712, and includes an X-axis direction guide and a ball screw mechanism provided on the front surface of the moving beam 75. The camera movement mechanism 77 can be driven to travel in the X-axis direction. As a result, the camera head 71 moves on the XY plane and performs shooting by using the camera moving mechanism 77 in the X-axis direction and the moving mechanism of the camera unit 7 and the cleaning unit 80 in the Y-axis direction. Can be done.

  The cleaning unit 80 is attached to the rear of the moving beam 75 and is movable in the Y-axis direction in the space between the mask sheet 51 and the printing stage 10 formed when the table 24 is lowered. The cleaning unit 81 is provided with a cleaning head 81 that can be moved up and down.

  Further, as shown in FIG. 5, the cleaning unit 80 is equipped with a belt-like cleaning tape 82 that is fed from a roll 82 a and passes over the cleaning head 81 and is taken up by a take-up roller 82 b. The take-up roller 82b is driven to rotate by driving means (not shown). When the cleaning head 81 is raised to the raised position, the cleaning tape 82 comes into contact with the lower surface of the mask sheet 51 and cleaning is performed.

  Further, the cleaning device 8 sucks through the cleaning tape 82, thereby sucking the solder paste adhering in the opening (pattern hole) formed in the mask sheet 51 to the lower surface side, and the cleaning tape 82. And a cleaning liquid supply means 840 (see FIG. 6) for supplying a cleaning liquid having volatility such as alcohol.

  The suction means 83 includes a suction chamber 83b disposed below the cleaning tape 82 in the cleaning head 81, and a blower 83d connected to the suction chamber 83b via a duct 83c. The suction chamber 83b is provided with a suction nozzle 83a extending upward toward the cleaning tape 82. A suction opening having a width corresponding to the size of the mask sheet 51 in the X-axis direction is provided at the tip of the suction nozzle 83a. Is formed.

  As shown in FIG. 6, the cleaning liquid supply means 840 is provided with a tank 86 for storing the cleaning liquid, a supply pipe 84 for supplying the cleaning liquid in the tank 86 to the cleaning tape 82, and in the middle of the supply pipe 84. And a pump 85.

  The tank 86 is fixedly attached to the printing press housing 1 with a bracket 86a. The tank 86 is provided with a liquid level detection sensor (liquid level detection means) 87 for detecting the liquid level of the cleaning liquid in the tank 86.

  The pump 85 is a fixed type (for example, 90 cc / min) with a check valve.

  One end 841 of the supply pipe 84 is positioned below the cleaning tape 82 and clamped and fixed to the cleaning head 81 in a state of extending in a substantially vertical direction, while the other end 842 enters the tank 86. In the state, it is connected to the tank 86, and the opening on one end 841 side is a discharge port 84a through which the cleaning liquid flows out. The other end 842 of the supply pipe 84 is configured by a substantially L-shaped fixed pipe, but the other part is configured by a flexible hose.

  Further, at one end 841 of the supply pipe 84, a cleaning liquid detection sensor (cleaning liquid detection means) 88 for detecting the presence or absence of the cleaning liquid in the supply pipe 84 is provided in a portion extending in a substantially vertical direction near the discharge port 84a. In addition, a solenoid valve 89 is provided on the downstream side (upper side) of the cleaning liquid detection sensor 88.

  The solenoid valve 89 is for suppressing evaporation of the cleaning liquid, and is opened and closed in accordance with the start and end of the cleaning operation. The solenoid valve 89 can be omitted.

  As shown in FIG. 7, the cleaning liquid detection sensor 88 is a light transmission sensor having a light projecting section 88a and a light receiving section 88b. When there is no cleaning liquid in the supply pipe 84, the cleaning liquid detection sensor 88 comes out of the light projecting section 88a. The light is refracted by the supply pipe 84 and reaches the light receiving part 88b (two-dot chain arrow). However, when there is a cleaning liquid in the supply pipe 84, the light emitted from the light projecting part 88a is washed as indicated by the solid line arrow. Since it passes through the inside, it does not reach the light receiving portion 88b, and thereby the presence or absence of the cleaning liquid in the supply pipe 84 can be detected.

  The liquid level detection sensor 87, the cleaning liquid detection sensor 88, and the pump 85 are connected to the controller 9 as shown in FIG. The control unit 9 is for performing a preparatory work before the cleaning work at the start of cleaning. Further, a display unit 91 made up of a display device and a notification unit 92 made up of a buzzer or the like are connected to the control unit 9 so that the display unit 91 and the notification unit 92 are activated when an abnormality occurs as will be described later. ing.

  Next, the operation of the printing machine of this embodiment will be described.

At the time of printing, the substrate W to be printed is first carried from the upstream conveyor 11 onto the main conveyor 20 of the printing stage 10, and then the placement table 29 is lifted and the substrate W is pushed up to a predetermined height before the clamp unit. 3, the elevating table 24 is further raised, and the substrate W is placed on the lower surface of the mask sheet 51 held by the mask sheet holding unit 5. After the substrate W is set in this way, the squeegee unit 6 is operated, and the solder paste is applied to the substrate W through the mask sheet 51 by the squeegee 61, and printing is performed.

  After completion of printing, clamping by the clamp unit 3 is released, the mounting tail 29 and the lifting table 24 are lowered, and the printed substrate W is transferred to the main conveyor 20 and further to the downstream conveyor 12. It is carried out.

  In addition, when the mask sheet 51 is cleaned, first, a preparatory work is performed by the control unit 9. The preparatory work will be described in detail below with reference to the flowchart of FIG.

  The controller 9 first takes in the output of the liquid level detection sensor 87 (step S1). And the control part 9 judges whether the liquid level height which the liquid level detection sensor 87 detects is more than an appropriate value (step S2), and when the liquid level height is less than an appropriate value ( The maintenance warning A is given to the user (NO in step S2) (step S3). The maintenance warning A is performed by displaying, for example, “the cleaning liquid in the tank is insufficient” on the display unit 91 and sounding an alarm by the notification unit 92.

  On the other hand, when the liquid level detected by the liquid level detection sensor 87 is not less than the appropriate value (YES in step S2), the control unit 9 performs timer initialization (T = 0) (step S4).

  Next, the control unit 9 takes in the output of the cleaning liquid detection sensor 88 (step S5), and detects whether there is cleaning liquid in the supply pipe 84, that is, whether the cleaning liquid detection sensor 88 detects the presence of cleaning liquid or not. (Step S6).

  When there is a cleaning liquid in the supply pipe 84 (YES in step S6), the control unit 9 starts driving the pump 85, and after a set time (corresponding to a predetermined time of the present invention) has elapsed from the start of driving the pump 85. The pump is stopped and the pump 85 is driven for a set time. As a result, the preparatory work is completed, and then a normal cleaning work is performed (step S12).

  The set time is set to such an extent that the pump 85 can send out the cleaning liquid in an amount sufficient to wet the cleaning tape 82 and the volume downstream of the cleaning liquid detection sensor 88 in the supply pipe 84. For example, 2.5 seconds. Therefore, regardless of the amount of cleaning liquid remaining on the downstream side of the cleaning liquid detection sensor 88 of the supply pipe 84, at least the supply amount of cleaning liquid flows out from the discharge port 84a of the supply pipe 84 and is supplied to the cleaning tape 82. The cleaning tape 82 is impregnated.

  On the other hand, when there is no cleaning liquid in the supply pipe 84 (NO in step S6), the control unit 9 starts driving the pump 85, drives the pump 85 for only 1 second (step S7), and sets T to 1 second. Add (step S8). Then, the control unit 9 determines whether T is less than 10 seconds (corresponding to the third predetermined time of the present invention) (step S9), and from step S5 to step S8 until T exceeds 10 seconds. Is repeated (YES in step S9).

  In the meantime, when the cleaning liquid detection sensor 88 detects that the cleaning liquid is present in the supply pipe 84, that is, when it is detected that the cleaning liquid detection sensor 88 changes from being absent to being present (YES in step S6), the control is performed. The unit 9 drives the set time pump 85 from the time of detecting it (step S11), finishes the preparation work, and shifts to the normal cleaning work (step S12).

  On the other hand, when the cleaning liquid detection sensor 88 does not detect the presence of the cleaning liquid in the supply pipe 84 during that period, that is, when the cleaning liquid detection sensor 88 does not detect the change from the absence of the cleaning liquid to the presence, the control is performed. The unit 9 issues a maintenance warning B for the user (step S10). This maintenance warning B is performed by displaying, for example, “cleaning liquid is leaking” or “cleaning liquid is not flowing” on the display unit 91 and sounding an alarm by the notification unit 92.

  During a normal cleaning operation, a moving beam 75 including a cleaning unit 80 is sent into a space generated below the mask sheet 51 as the printing stage 10 is lowered. Then, the cleaning head 81 of the cleaning unit 80 rises and the cleaning tape 82 contacts the lower surface of the mask sheet 51. In this state, the cleaning unit 80 moves in the Y axis direction along the lower surface of the mask sheet 51. At the same time, the blower 83d of the suction means 83 is activated to suck air from the suction nozzle 83a.

  Accordingly, a suction force acts on the mask sheet 51 from the suction opening of the suction nozzle 83a via the cleaning tape 82, and the solder paste attached to the mask sheet 51 is sucked and wiped off by the cleaning tape 82.

  The cleaning unit 80 reciprocates along the lower surface of the mask sheet 51, and the cleaning tape 82 that has been impregnated with the cleaning liquid in the forward path contacts the lower surface of the mask sheet 51, and the cleaning liquid in the return path. The cleaning liquid supply means 840 and the take-up roller 82b are controlled so that the dry cleaning tape 82 not impregnated with is in contact with the lower surface of the mask sheet 51.

  As described above, in the printing press according to the present embodiment, the supply pipe 84 is provided with the cleaning liquid detection sensor 88 on the downstream side of the pump 85. Therefore, the setting is performed in a state where the cleaning liquid detection sensor 88 detects the presence of the cleaning liquid. When the time pump 85 is driven, the cleaning liquid can flow out from the supply pipe 84 and be supplied to the cleaning tape 82. In addition, even if the pump 85 is driven while the cleaning liquid detection sensor 88 detects the absence of the cleaning liquid, if the cleaning liquid detection sensor 88 does not detect the change from the absence of the cleaning liquid to the presence, the supply pipe 84 is thereby used. Therefore, even if an abnormality occurs, it is possible to perform maintenance quickly, and it is possible to prevent the cleaning liquid from being supplied to the cleaning tape 82 due to the abnormality. Therefore, it becomes possible to supply the cleaning liquid to the cleaning tape 82 so that there is no shortage.

  In addition, since the cleaning liquid detection sensor 88 detects that the cleaning liquid is present in the supply pipe 84 until the predetermined time elapses, that is, the set time pump 85 is driven, the cleaning liquid that flows out from the supply pipe 84. This amount can be controlled by the driving time of the pump 85, and the amount of extra cleaning liquid consumed can be kept small. Accordingly, the cleaning liquid can be supplied to the cleaning tape 82 while suppressing the consumption of the cleaning liquid.

  Further, when the liquid level detected by the liquid level detection sensor 87 is less than an appropriate value, that is, when the amount of the cleaning liquid in the tank 86 is small, the maintenance warning A is performed. Can quickly replenish the tank 86 with the cleaning liquid.

  Further, in the case where the driving of the pump 85 is started in a state where the cleaning liquid detection sensor 88 detects the absence of the cleaning liquid, and the cleaning liquid detection sensor 88 does not detect the change from the absence of the cleaning liquid to the presence within 10 seconds. Since the maintenance warning B is performed, an abnormality such as a crack in the supply pipe 84 can be promptly notified to the user.

  Further, since the cleaning liquid detection sensor 88 is provided in a portion extending in the substantially vertical direction in the vicinity of the discharge port 84a, the speed at which the liquid level of the cleaning liquid gradually decreases after the driving of the pump 85 is stopped is extremely slow in evaporation. On the other hand, since it is relatively early in the case of leakage, is evaporation caused by a decrease in the cleaning liquid depending on the time from when the driving of the pump 85 is stopped until the cleaning liquid detection sensor 88 detects that there is no cleaning liquid in the supply pipe 84? You can see if there is a leak. For this reason, when the controller 9 detects that the cleaning liquid detection sensor 88 changes from the presence of the cleaning liquid to the absence of the cleaning liquid within a certain time (corresponding to the second predetermined time of the present invention) after stopping the driving of the pump 85. In addition, if a warning is given, only the leak can be notified to the user.

  Although the tank 86 can be provided in the cleaning unit 80, the tank 86 is fixedly provided in the printing machine housing 1 as in the present embodiment, and a portion other than the other end 842 of the supply pipe 84 is flexible. If it comprises a property hose, the movable cleaning unit 80 can be reduced in weight.

  In addition, the specific structure of the screen printing machine of this invention is not limited to the said embodiment, A various change is possible.

  For example, if the cleaning liquid detection sensor 88 is provided on the downstream side of the pump 85, the effects of the present invention can be obtained. However, if the cleaning liquid detection sensor 88 is provided in the vicinity of the discharge port 84a as in the above-described embodiment, the distance between the discharge port 84a and the cleaning liquid detection sensor 88 is shortened, so that a little amount of cleaning liquid is consumed. The consumption of the cleaning liquid can be further suppressed.

  Further, in addition to the control shown in the flowchart of FIG. 9, the control unit 9 starts driving the pump 85 after detecting that the cleaning liquid detection sensor 88 changes from the presence of the cleaning liquid to the absence of the cleaning liquid. After the elapse of time, the second control for stopping the driving of the pump 85 may be performed, or only the second control may be performed.

It is a side view of the screen printer concerning one embodiment of the present invention. It is a front view of the printing machine. It is a schematic perspective view showing the positional relationship of each part of the printing press. It is a schematic perspective view which shows the camera unit and cleaning unit of the said printing machine. It is the side view which showed the said cleaning unit typically. It is a schematic diagram of the part which supplies a washing | cleaning liquid to a cleaning tape among cleaning apparatuses. It is explanatory drawing about a washing | cleaning liquid detection sensor. It is a block diagram of a cleaning device. It is a flowchart of a cleaning apparatus.

Explanation of symbols

51 Mask Sheet 80 Cleaning Unit 82 Cleaning Tape 84 Supply Pipe 84a Discharge Port 85 Pump 86 Tank 87 Liquid Level Detection Sensor (Liquid Level Detection Means)
88 Cleaning fluid detection sensor (cleaning fluid detection means)
9 Control unit

Claims (6)

In a screen printing machine provided with a cleaning unit in which a cleaning tape impregnated with a cleaning liquid is brought into contact with the lower surface of the mask sheet and the solder paste attached to the mask sheet is wiped off,
A tank for storing the cleaning liquid; a discharge port for the cleaning liquid; a supply pipe for supplying the cleaning liquid in the tank to the cleaning tape; a pump provided in the supply pipe ; A control unit for controlling the drive ,
The supply pipe is provided with cleaning liquid detection means for detecting the presence or absence of the cleaning liquid in the supply pipe at a position downstream of the pump and in the vicinity of the discharge port .
The control unit starts driving the pump in a state where the cleaning liquid detection means detects the absence of cleaning liquid, and after detecting that the cleaning liquid detection means changes from the absence of cleaning liquid to the presence, the pump is driven for a predetermined time. After stopping the pump drive, or after detecting that the cleaning liquid detecting means changes from the presence of the cleaning liquid to the absence of the cleaning liquid, the pump driving is started and the pump is driven for a predetermined time after the pump driving is started. screen printing machine, characterized or that you implement at least one stops driving the. When the predetermined time is the first predetermined time,
The control unit warns the user when it detects that the cleaning liquid detecting means changes from the presence of the cleaning liquid to the absence of the cleaning liquid within a second predetermined time after stopping the driving of the pump. The screen printing machine according to claim 1. Wherein, prior Kiarai washing liquid detection means after starting the driving of the pump in a state in which detected the absence washing liquid, the washing liquid detection means is changed to there from without into flask third predetermined time The screen printing machine according to claim 1 or 2, wherein a warning is given to a user when the above is not detected . The discharge port of the supply pipe is positioned below the cleaning tape, and the supply pipe extends in a substantially vertical direction in the vicinity of the discharge port, and the cleaning liquid is disposed in a portion extending in the substantially vertical direction. screen printing machine according to any one of claims 1 to 3 sensing means characterized that you have provided. The tank is provided with liquid level detection means for detecting the liquid level height of the cleaning liquid in the tank, and the control unit is configured such that the liquid level height detected by the liquid level detection means is less than a predetermined value. in some cases, the screen printing machine according to any one of claims 1 to 4, characterized in der Rukoto performs warning to the user. The cleaning unit is movable along the lower surface of the mask sheet, while the tank is fixedly provided, and one end of the supply pipe is fixed to the cleaning unit. the other end be connected to the tank, a screen according to any one of claims 1 to 5, characterized in that a portion other than the other end of the supply pipe is composed of a flexible hose Printer.

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