JPH07108455B2 - Spray control method of spray flux - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray fluxer mounted on an automatic soldering apparatus and spraying flux onto a work such as a printed circuit board to apply the flux by detecting the position and the total length of the work. The present invention relates to a spray control method for controlling the timing of spraying.

[0002]

2. Description of the Related Art Conventionally, a spray fluxer for spraying a flux onto a printed circuit board as a work needs to detect the position of the board. For this reason, a nozzle for flux spraying and a work for detecting the board through a conveyor. Positioning the sensor on the same line so as to face it, starting the spraying at the same time when the work sensor detects the substrate, and ending this spraying after passing, and positioning the work sensor in front of the nozzle (carry-in side), A method is used in which spraying is started from a nozzle after a certain period of time from detection of a substrate by a work sensor using a delay relay or the like.

[0003]

First, when the nozzle and the work sensor are opposed to each other on the same line via a conveyor, there is a problem that the work sensor is easily contaminated by the flux sprayed from the nozzle, which causes a malfunction.

Further, in the method of starting the spraying after a fixed time from the substrate detection by the delay relay, when the substrate transfer speed is changed, the position of the substrate after the fixed time is different,
It is also necessary to change the delay time set in the delay relay. This change is not easy.

The present invention has been made in view of the above points, and the work sensor is not contaminated by the sprayed flux, and the start of spraying and the end of spraying are performed at accurate timings not affected by the work transfer speed. It is an object of the present invention to provide a spray control method capable of determining

[0006]

According to the present invention, in a spray fluxer for applying flux to a work P by spraying the flux f from the nozzle 14 toward the work P conveyed by a conveyor 11, the nozzle 14 is used. A constant pulse corresponding to the distance L1 from the work sensor 15 to the nozzle 14 among the pulse signals transmitted in synchronization with the work transfer speed after the work tip is detected by the work sensor 15 located closer to the work loading side. When the number is counted, the atomization of flux is started and the work sensor
The total length L2 of the work P in the conveying direction is determined by the number of pulses transmitted from the detection of the work tip by 15 to the end of the work detection.
Is measured, and when the number of pulses corresponding to the total length of the work is counted from the start of the flux spraying, the spraying of the flux is terminated.

[0007]

According to the present invention, the flux spraying is started when the constant pulse number corresponding to the distance L1 between the work sensor and the nozzle is counted from the time when the work sensor 15 detects the work tip. Then, while the work sensor 15 is detecting the work P, the total length L2 of the work P in the conveyance direction is measured by the number of pulses counted, and the flux is sprayed by the number of pulses corresponding to the total length of the work.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

As shown in FIG. 1, a pair of endless chains 12 are wound around a sprocket 13 and arranged in parallel as a conveyor 11 for carrying a printed circuit board P as a work. Conveying pawls (not shown) are provided on the chain 12 at a constant pitch over the entire circumference.
The substrate P is conveyed in the direction of the arrow in FIG. 1 while being sandwiched between the 12 conveying claws.

A nozzle 14 for spraying and applying flux to the lower surface of the substrate P is arranged in the substrate transport path.
Further, a work sensor (photo sensor) 15 for detecting the presence or absence of the substrate P is arranged on the work loading side of the nozzle 14.

One of the sprocket shafts 16 of the conveyor 11 is provided with a count sensor 21 which operates in synchronization with the substrate transfer speed of the conveyor 11. In this count sensor 21, a dog disc 22 is coaxially and integrally attached to a sprocket shaft 16, and a large number of small holes 23 are provided at a constant pitch on the peripheral edge of the dog disc 22. The sensor 24 is arranged. The light emitted from the projector of the photo sensor 24 is transmitted through the small hole 23 of the rotating dog disc 22.
Thus, it reaches the light receiver intermittently, and the counting pulse signal is obtained from the light receiver.

The pulse signals output from the count sensor 21 are output at intervals proportional to the work transfer speed, that is, the substrate transfer speed, and the substrate moving distance can be known from the number of pulses, so that as will be described later. It is possible to detect the moving distance and the entire length of the substrate P by the number of pulses from the count sensor 21.

As shown in FIG. 2, in the spray fluxer according to the present invention, the flux F is pressurized and supplied from the pressure tank 25 to the nozzle 14 provided at a fixed position, and the nozzle 14 is applied to the printed circuit board P. The flux f is sprayed toward the printed circuit board P to apply the flux.

As shown in FIG. 3, a needle valve 32 is vertically movable in the spray hole 31 of the nozzle 14,
A piston 34 of an air cylinder 33 is connected to the needle valve 32 by a rod 35. The piston 34 descends by the air pressurized and supplied from the air hole 36 into the cylinder, and when the air is exhausted, the spring 37 in the cylinder 37
Is raised by. The side surface of the nozzle 14 is provided with a flux hole 38 connected to the pressure tank 25,
The flux supplied into the nozzle through the flux holes 38 is sprayed from the spray holes 31 when air is supplied to the cylinder 33, and stopped when exhausted from the cylinder 33.

As shown in FIG. 4, the flux f sprayed from the nozzle 14 is sprayed in a slender shape in the width direction of the printed board P (direction perpendicular to the traveling direction). In this way, the spray holes 31 of the nozzle 14 are formed.

Returning to FIG. 2, the nozzle 14 has an air pressure source.
Flux F in the tank is supplied from the tank 25 pressurized by 41 through the conduit 42 and the flux hole 38, and the air cylinder 33 for opening and closing the needle valve is connected from the pneumatic source 43 to the conduit. Needle valve operating air intermittently controlled by a solenoid valve 45 in
Supplied by.

The solenoid valve 45 is intermittently turned on / off by a sequencer 47 which is operated based on a substrate detection signal obtained by a work sensor 15 provided for a substrate transfer path, and output from the sequencer 47. An air signal is switched to an air supply position by the ON signal, air is supplied to the air cylinder 33 to open the spray hole 31 of the nozzle 14, and an OFF signal output from the sequencer 47 switches the air supply position to the air exhaust position. Then, the spray hole 31 of the nozzle 14 is closed.

The sequencer 47 is the count sensor for transmitting a pulse signal in synchronization with the operating speed of the conveyor 11.
The pulse signal for counting is received from 21 and the number of pulses is counted to control the flux spray start and end, that is, the flux spray time.

Next, the operation of this embodiment will be described.

When the printed circuit board P to which the flux is applied advances and the work sensor 15 located on the work carrying-in side of the nozzle 14 detects the front end of the board P as shown in FIG. When the number of pulses corresponding to a predetermined distance L1 between the pre-programmed work sensor 15 and nozzle 14 is counted, the pulse signal transmitted from the count sensor 21 that operates in synchronization with Is located immediately above the nozzle 14, spraying of the flux f is started.

In this flux spraying, the electromagnetic valve 45 shown in FIG. 2 is intermittently switched by the spraying pulse signal output from the sequencer 47, and atomized from the nozzle 14 toward the printed board P being conveyed. The flux f is applied to the back surface of the substrate P by intermittently pulse-spraying the flux f.

At this time, since the nozzle 14 is in the fixed position, the coating pattern of the flux f pulse-sprayed in the elliptical shape is also in the fixed position, but since the substrate P is moving, as shown in FIG. In addition, while the ellipse coating pattern of the flux f relatively moves on the lower surface of the substrate P, the flux coating patterns are polymerized.

The flux spraying time depends on the work sensor.
The sequencer 47 counts the number of pulses transmitted from the count sensor 21 from the detection of the substrate front end by 15 to the end of the substrate detection, and measures the total length L2 of the substrate P in the conveyance direction. When the sequencer 47 has finished counting from the start of spraying, the spraying of flux is terminated.

FIG. 5 is a diagram simply showing the above series of operations. After the work sensor 15 detects the front end of the substrate, the sequencer outputs a constant pulse number corresponding to a constant distance L1 from the sensor 15 to the nozzle 14. When the spray start signal is output after 47 counts, the solenoid valve 45 supplies the air pressure for the nozzle opening to the air cylinder 33 of the nozzle 14, and the spray hole of the nozzle 14 is supplied.
31 opens. Furthermore, when the sequencer 47 counts the number of pulses corresponding to the total length L2 of the substrate P in the transport direction detected by the work sensor 15 from the start of spraying, the sequencer 47 outputs a spray end signal and switches the solenoid valve 45. By exhausting the opening pressure from the air cylinder 33 of the nozzle 14, the spray hole 31 of the nozzle 14 is closed.

The means for generating the counting pulse signal in the count sensor 21 is not limited to the photo sensor 24, and a proximity sensor (magnetic sensor) may be used instead of the photo sensor 24, for example. In that case, a magnet may be attached to the dog disc 22 instead of the small hole 23.

Further, although L1 <L2 is satisfied in FIG. 1, it is needless to say that the present invention can be implemented even when L1 ≥ L2.

[0027]

According to the present invention, since the work sensors are spaced apart from the nozzle on the work carrying-in side and are not arranged to face each other, it is possible to prevent the work sensors from being contaminated by the sprayed flux. Also, the distance from the work sensor to the nozzle and the total length in the carrying direction of the work are converted into the number of pulses of the pulse signal transmitted in synchronization with the work carrying speed,
Since the start and end timings of the flux spraying are determined, the timing of the flux spraying can be accurately adjusted by the invariable number of pulses even if the work transfer speed is changed, and it is not necessary to adjust the time.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a spray control method of the present invention.

FIG. 2 is a circuit diagram of a control system and a pneumatic circuit in the embodiment.

FIG. 3 is a sectional view of a nozzle used in the embodiment.

FIG. 4 is a plan view of a flux pattern applied to a substrate in the same example.

FIG. 5 is a flow chart diagrammatically illustrating the operation of the above embodiment.

[Explanation of symbols]

 f Flux P Substrate as work 11 Conveyor 14 Nozzle 15 Work sensor

Claims (1)

[Claims] 1. A spray fluxer for applying flux to a work by spraying the flux from a nozzle toward a work conveyed by a conveyor, wherein the work tip located by a work sensor located on the work carry-in side of the nozzle. After detection, when a constant number of pulses corresponding to the distance from the work sensor to the nozzle is counted among the pulse signals transmitted in synchronization with the work conveyance speed, the spraying of the flux is started, and the work sensor By measuring the total length in the transport direction of the work by the number of pulses transmitted from the detection of the tip of the work by the end of the work detection, when the number of pulses corresponding to this total work length is counted from the start of the flux spraying, the flux A spray control method for a spray flux, characterized by terminating spraying.