JP2003273588A - Surface mounting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface mounting apparatus which is provided at low cost and capable of accurately judging whether a suction nozzle sucks up a component or not and detecting a necessary cleaning time even if the suction nozzle is replaced with the other having a different diameter. <P>SOLUTION: A first suction path 23 and a second suction path 24 are provided in parallel between a vacuum generator 22 and the suction nozzle 5. Opening and closing valves 25 and 26 and throttle valves 27 and 28 are provided to the suction paths 23 and 24. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mounter equipped with a sensor for detecting a pressure change in a suction nozzle.

[0002]

2. Description of the Related Art Conventionally, in a surface mounter that supplies mounting components to a printed wiring board, the mounting components are sucked by a suction device and transferred from a component feeder such as a tape feeder to the printed wiring board. . The suction device includes a suction nozzle having an air suction port opened, and an air pump that sucks air from the suction nozzle. The suction nozzle is mounted so that the air suction port is blocked by a mounting component. The mounting component is sucked by contacting the mounting component.

Further, in this suction device, a vacuum pressure sensor is provided in the middle of the air suction passage, and it is detected based on the pressure detected by this sensor whether or not the mounting component is sucked by the suction nozzle. Is configured to.
To determine whether or not this suction is present, set the pressure that will generate the minimum required suction force to suck the mounting component with the suction nozzle as the determination pressure, and compare this determination pressure with the actually detected pressure. Done. That is, when the pressure detected by the vacuum pressure sensor is lower than the determination pressure (vacuum pressure = absolute value of negative gauge pressure, so-called negative pressure is high), the mounting component is sucked by the suction nozzle. If the detected pressure is higher than the determination pressure (vacuum pressure is low), it is determined that the adsorption is not performed.

The pressure detected by the vacuum pressure sensor is used to determine the presence or absence of suction, as well as to detect the cleaning time of the suction nozzle, or to detect the presence or absence of suction after the mounting component is placed on the printed wiring board. It is also used to detect and determine a placement error. The air suction port of the suction nozzle may become narrower as foreign matter adheres to the opening as the number of suctions increases. This is because the influence of the pressure reduction action by the suction of becomes relatively large, and the pressure of the suction system becomes relatively low. By thus detecting that the pressure of the suction system has decreased, it is possible to determine whether or not it is time to clean the suction nozzle.

Further, in the case where the mounting component is attached to the suction nozzle for some reason which cannot be predicted even though the suction nozzle is elevated after the mounting component is placed on the printed wiring board. Since the pressure inside the nozzle is lower than when the mounting component is not sucked into the suction nozzle (hereinafter, this state is referred to as the nozzle open state), a sensor can detect this to prevent mounting errors. You can detect what happened.

On the other hand, in recent surface mounters, a plurality of suction nozzles having different suction surface shapes and sizes are prepared so that many types of mounting components can be mounted. Among nozzles, one that fits a mounting component is selected and mounted.

[0007]

However, if the suction nozzle is replaced with another suction nozzle having a small air suction port, it may not be possible to accurately determine the presence or absence of suction and detect the cleaning time. It was This is because the pressure in the nozzle when the mounting component is sucked by the suction nozzle (hereinafter, this state is called the nozzle suction state) is almost constant even if the suction nozzle is replaced, but the air suction port By replacing the suction nozzle with a relatively small diameter,
This is because the pressure inside the nozzle in the nozzle open state is relatively low.

That is, by exchanging a large-diameter suction nozzle with a small-diameter suction nozzle, the pressure difference between the pressure in the nozzle in the nozzle suction state and the pressure in the nozzle in the nozzle open state is changed before the exchange. This is because the vacuum pressure sensor has to detect the detected pressure for comparing the magnitude with the determination pressure within this narrow pressure range. In the conventional surface mounter, a diaphragm type is used as a vacuum pressure sensor, and one that can withstand a large pressure change when using a suction nozzle with a large air suction port is used. There is. Since such a vacuum pressure sensor does not have the resolution capable of detecting the judgment pressure within the narrow pressure range as described above, the accuracy in detecting the judgment pressure becomes low. As a result, the determination of the presence or absence of adsorption becomes inaccurate as described above.

Such a problem can be solved by providing a plurality of vacuum pressure sensors so as to match the diameter of the air suction port of the suction nozzle. However, if such a configuration is adopted, the vacuum pressure sensor is connected. The same number of electronic components as the A / D conversion circuit and the vacuum pressure sensor are required, which significantly increases the cost.

The present invention has been made in order to solve such a problem, and it is possible to determine the presence or absence of suction and to detect the cleaning time even if the suction nozzle is replaced with a nozzle having a different diameter while reducing the cost. It is an object of the present invention to provide a surface mounter that can be accurately performed.

[0011]

To achieve this object, a surface mounter according to the present invention has a plurality of suction passages connected in parallel on the downstream side of the sensor in a suction system of a suction nozzle. On-off valves and throttles are provided in these passages. According to the present invention, by opening all the on-off valves, air can be sucked from one adsorption nozzle into the plurality of suction passages to relatively reduce the pressure in the nozzles, and By reducing the number, the intake air flow rate at the adsorption nozzle is reduced and the pressure inside the nozzle is relatively increased. Therefore, when replacing the suction nozzle with a nozzle with a relatively small air suction port, increase the differential pressure between the pressure inside the nozzle when the nozzle is sucking and the pressure inside the nozzle when the nozzle is open. You can

As a result, even when the suction nozzle is replaced with a suction nozzle having a relatively small diameter, the range of pressure detected by the vacuum pressure sensor can be widened. It is possible to accurately determine the presence / absence of the cleaning and the detection of the cleaning time with one vacuum pressure sensor.

A surface mounter according to a second aspect of the present invention is the surface mounter according to the first aspect of the invention, wherein the throttle has a different air flow rate at a predetermined pressure difference for each suction passage. It is what has been. According to this invention, the suction system is configured to suck air at an air flow rate that matches the diameter of the air suction port of the suction nozzle,
The vacuum pressure characteristics upstream of the throttle can be changed.

That is, when the suction nozzle having a relatively large air suction port is used, the on-off valve of the suction passage having a relatively large air flow rate is opened, and the suction nozzle having the relatively small diameter is used. When using, the differential pressure between the pressure inside the nozzle when the nozzle is adsorbed and the pressure inside the nozzle when the nozzle is open is opened by opening the on-off valve in the suction passage where the air flow rate becomes relatively small. Even if the suction nozzles are replaced, they can be made approximately equal.

A surface mounter according to a third aspect of the present invention is the surface mounter according to the first aspect of the present invention, in which the throttles have the same air flow rate at a predetermined pressure difference for each suction passage. It is used. According to the present invention, when providing a plurality of suction passages, the number of kinds of diaphragms can be set to one, so that the structure is simplified and the assembling work and maintenance are facilitated.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An embodiment of a surface mounter according to the present invention will be described in detail below with reference to FIGS. FIG. 1 is a plan view of a surface mounter equipped with a suction nozzle according to the present invention, and FIG. 2 is a front view of the same. 3 to 6 are views showing the structure of an adsorption device, FIG. 3 shows a state in which an adsorption nozzle having a relatively large air suction port is used, and FIG. 4 shows a relative air suction port. Fig. 5 shows a state in which a small suction nozzle is used.
Shows a state in which the suction nozzle having the largest air suction port is used, and FIG. 6 shows a state in which a positive pressure is applied. Figure 7
Is a graph showing a change in pressure inside the nozzle when an adsorption nozzle having a relatively large air inlet is used, and FIG. 8 uses an adsorption nozzle having a relatively small air inlet. It is a graph which shows the change of the pressure in a nozzle at this time. FIG. 9 is a graph showing the flow characteristics of the intake air of the ejector.

In these figures, the reference numeral 1 indicates a surface mounter according to this embodiment. The surface mounter 1 includes a conveyor 4 for transporting the printed wiring board 3 above the base 2, a suction device 6 (see FIGS. 3 to 6) having a suction nozzle 5 (see FIG. 2), and a suction device. A nozzle moving means 7 for moving the nozzle 5 is provided, and the structure is the same as the conventional one except that the suction device 6 is different.

In the conveyor 4, the printed wiring board 3 is moved in the left-right direction of the base 2 in FIG.
Direction) and is held in the working position by a clamp mechanism (not shown). On both sides of the conveyor 4, there are provided a tape feeder 9 in which mounting components 8 (see FIG. 1) are housed, and a camera 10 as an imaging type determination means (not shown). The imaging type determination means is configured to compare an image taken by the camera 10 with an image in a normal state, and detect presence or absence of component suction and a component suction position.

The nozzle moving means 7 includes the conveyor 4
Between the fixed rails 11, 11 and the Y-direction moving device 12 having two fixed rails 11 extending in a direction above the conveyance direction of the conveyor 4 (hereinafter, this direction is simply referred to as the Y direction). Movable rail 1 that was laid over
3, an X-direction moving device 14 and a nozzle holding head unit 15 attached to the X-direction moving device 14.

The Y-direction moving device 12 moves the movable rail 13 of the X-direction moving device 14 in the Y-direction by means of a ball screw shaft extending along the fixed rail 11 and a servomotor 17 for driving the ball screw shaft 16. It is configured to reciprocate. The X-direction moving device 14 is configured to reciprocate the head unit 15 in the X-direction by a ball screw shaft 18 extending along the movable rail 13 and a servo motor 19 that drives the ball screw shaft 18.

The head unit 15 includes a suction nozzle 5
A plurality of suction heads 21 for holding the suction heads are provided at intervals in the X direction, and an elevating device (not shown) for moving each suction head 21 in the vertical direction (Z direction) and rotating around the vertical direction as an axis. Rotating drive device (not shown)
And are provided. Further, a suction nozzle mounting base (not shown) is provided on the base 2, in which suction nozzles 5 having a plurality of sizes and different suction port diameters of the air suction ports are accommodated. The control device 31, which will be described later, moves the head unit 15 to a position above the suction nozzle mounting table as needed, and replaces the suction nozzle 5 for each desired suction head 21. The surface mounter 1 according to this embodiment has three
The type of suction nozzle 5 is replaced and used.

The suction device 6 is, as shown in FIGS.
A first suction passage 23 and a second suction passage 24 are interposed between the suction nozzle 5 and the vacuum generator 22. In the present embodiment, the vacuum generator 22 is composed of, for example, an ejector that sucks air using service air of a factory or the like as a pressure source.

The first suction passage 23 and the second suction passage 24 are provided with open / close valves 25 and 26, respectively, on the way, and are located upstream of the open / close valves 25 and 26. The diaphragms 27 and 28 are provided and connected to the suction nozzle 5 in parallel. The upstream ends of the first and second suction passages 23 and 24 are connected to an upstream passage 29 provided in the vicinity of the downstream side of the suction nozzle 5, and the downstream ends thereof are connected to the vacuum generating chamber. Each of them is connected to the container 22.

The on-off valves 25 and 26 are 3-port solenoid valves in this embodiment, and the same first suction passage 23 and second suction passage 24 are used. These on-off valves 25 and 26 are provided in the head unit 15 and can be opened and closed by a control device indicated by reference numeral 31 in FIG. The throttles 27, 28 correspond to the on-off valve 2
5 and 26 are provided in the head unit 15 and have different passage cross-sectional areas so that the air flow rate of the second suction passage 24 is smaller than the air flow rate of the first suction passage 23. Is used.

That is, the throttle 2 of the first suction passage 23
The second suction passage 2 is configured to have a large air flow rate that passes through when a pressure difference before and after the throttle 27 has a predetermined value, that is, an air flow rate at the predetermined pressure difference.
As the throttle 28 of No. 4, a throttle having a relatively small air flow rate at a predetermined pressure difference is used. In addition, the diaphragms 27 and 28 are the first and second diaphragms in this embodiment.
It is formed by a variable throttle so that the air flow rates of the suction passages 23 and 24 can be finely adjusted to cancel variations in the pipe length, the vacuum pressure of the vacuum generator 22, and the like.

The upstream passage 29 provided between the upstream end of each of the first and second suction passages 23 and 24 and the suction nozzle 5 is for detecting the pressure in the suction nozzle 5. The vacuum pressure sensor 32 is connected. As the vacuum pressure sensor 32, a diaphragm type sensor equivalent to a conventional one is used, which is connected to the control device 31 and sends detection data to the control device 31.

The control device 31 switches the opening / closing valves 25 and 26 between opening and closing so as to correspond to the replacement of the suction nozzle 5, and determines the presence or absence of suction based on the detection data of the vacuum pressure sensor 32 and the cleaning time. Is detected. Since the method of these determinations and detections is the same as the conventional one, detailed description thereof will be omitted here.

A positive pressure supply passage 33 is connected to the upstream passage 29. This positive pressure supply passage 33
Supplies the positive pressure to the suction nozzle 5 when the mounting component 8 is placed on the printed wiring board 3 and the suction of the suction nozzle 5 is stopped, so that the mounting component 8 quickly separates from the suction nozzle 5. The opening / closing valve 35 is interposed between the positive pressure air supply source 34 and the suction nozzle 5. The opening / closing valve 35 is also an electromagnetic valve, and the opening / closing is switched by the control device 31.

Next, the operation of the suction device constructed as described above will be described. First, three types of suction nozzles 5
Of these, the case where the suction nozzle 5 (for example, a standard suction nozzle) is installed so that the diameter of the air suction port becomes an intermediate size will be described. When using the suction nozzle 5, as shown in FIG. 3, the opening / closing valve 25 of the first suction passage 23 is opened and the opening / closing valve 26 of the second suction passage 24 is closed. The on-off valve 34 of the positive pressure supply passage 33 is closed.

By switching the opening / closing valves 25 and 26 in this manner, air is sucked into the adsorption nozzle 5 by an air flow rate regulated by the throttle 27 of the first suction passage 23, and the adsorption nozzle 5 is in a suction state. become. In order to transfer the mounting component 8 from the tape feeder 9 to the printed wiring board 3 by the suction nozzle 5, first, the suction nozzle 5
Is set to the suction state by the X-direction moving device 14 and the Y-direction moving device 12 and the mounting component 8 of the tape feeder 9 is mounted.
Of the head unit 15 and then lowered by the lifting device of the head unit 15.

When the suction nozzle 5 descends and comes into contact with the mounting component 8 from above, the mounting component 8 is sucked by the suction nozzle 5. When the suction nozzle 5 sucks the mounting component 8 in this manner, the pressure in the nozzle changes as shown in FIG. That is, the pressure in the nozzle is relatively high (vacuum pressure is relatively low) in the nozzle open state where the mounting component 8 is not sucked, but gradually decreases after the suction starts, and becomes the lowest in the nozzle suction state. become. The vacuum pressure referred to here is a pressure that becomes 0 at 1 atmospheric pressure and that the pressure value rises when the pressure is reduced.

The pressure difference between the pressure in the nozzle in the nozzle open state and the pressure in the nozzle in the nozzle suction state is indicated by P in FIG.
It shows with 1. In the suction nozzle 5 in which the differential pressure P1 can be made sufficiently large, the suctioned state can be stabilized by relatively increasing the suction air flow rate. The relationship between the position in each of the upstream passage 29 and the suction passages 23 and 24 from the air suction port to the vacuum generator 22 and the negative pressure is as follows. At the outside of the air suction port, the atmospheric pressure is zero and the negative pressure is 0. Due to the pressure drop due to the flow of air, the negative pressure increases as it approaches the vacuum generator 22, and the vacuum generator 22 reaches the maximum negative pressure. . When the flow of air is stopped, that is, when the air suction port is completely sealed, the upstream side passage 29 is provided after a lapse of time except for the transition.
And the inside of the suction passages 23 and 24 becomes the maximum negative pressure regardless of the position.

That is, in the nozzle suction state, the flow of air is stopped, but the pressure drop at the air suction port becomes extremely large, so that the suction passages 23 and 24 have almost the maximum negative pressure. On the other hand, in the nozzle open state, when passing through the air suction port, the pressure drops according to the diameter of the air suction port (the larger the opening, the smaller the pressure drop).
The pressure decreases (that is, the negative pressure increases) little by little as the suction passages 23 and 24 are directed downstream. The vacuum pressure in the nozzle open state in FIG. 7 is the pressure at the mounting position of the vacuum pressure sensor 32, and is the total pressure drop amount = a negative pressure value obtained by multiplying the maximum negative pressure value by the pressure drop ratio of the upstream portion. .

After the mounting component 8 is sucked by the suction nozzle 5 as described above, the presence or absence of suction is determined by the control device 31. This determination is performed by determining whether the pressure detected by the vacuum pressure sensor 32 is lower than the determination pressure. The vacuum pressure sensor 32 uses the differential pressure P
A pressure sensor that can accurately detect the pressure in the pressure range corresponding to 1 is used, and therefore, the comparison result between the determination pressure and the pressure in the nozzle in the nozzle suction state does not differ from the actual state. .

The suction operation described above is performed by the head unit 15
Is performed in all of the plurality of suction nozzles 5 provided. After the parts are picked up by all the suction nozzles 5,
The suction nozzle 5 is moved above the camera 10 by the X-direction moving device 14 and the Y-direction moving device 12. Then, the lower end of the suction nozzle 5 is photographed from below by the camera 10, and the mounting component 8 is mounted on the printed wiring board 3 in a later step.
The pickup position of the mounting component 8 is detected by the imaging type determination means so that it can be placed at the correct position when the mounting component 8 is placed.

After the detection by the imaging type determination means is completed, the suction nozzle 5 is moved by the X-direction moving device 14 and the Y-direction moving device 12 to a position above the predetermined mounting position of the printed wiring board 3, and then the elevating device. To lower. In this lowering step, the suction nozzle 5 is lowered by a predetermined distance so that the mounting component 8 is placed on the printed wiring board 3.

After the mounting component 8 is placed on the printed wiring board 3, the opening / closing valve 25 of the first suction passage 23 is closed and the positive pressure air supply passage is opened / closed as shown in FIG. Open the valve 35. The opening / closing valve 35 is closed immediately after it is opened. By this valve operation, the suction is instantaneously stopped by the suction nozzle 5, so that the mounting component 8 is pressed from the suction nozzle 5 and the printed wiring board 3 while maintaining the state where the mounting component 8 is placed on the printed wiring board. Placed.

After mounting the mounting component 8 on the printed wiring board 3 in this manner, the suction nozzle 5 is raised and returned to the initial position together with the head unit 15. At this time, the opening / closing valve 25 is opened again, and the control device 31 determines again whether or not the adsorption has occurred. That is, when the pressure in the nozzle detected by the vacuum pressure sensor 32 is higher than the determination pressure, it is determined that the placement is successful, and when the pressure is opposite, the placement is unsuccessful. Is determined. When an error such as a mounting failure or a suction failure is detected, the control device 31
Activates an alarm (not shown) and stops the entire device.

Further, the control device 31 determines whether or not the suction nozzle 5 has reached the cleaning time, for example, while the suction nozzle 5 is being returned to the initial position after the mounting step is completed. This determination is performed by comparing the pressure in the nozzle detected by the vacuum pressure sensor 32 with a predetermined pressure for cleaning determination.

The suction nozzle 5 is replaced so as to correspond to the type of mounting component 8 to be suctioned. Of the three types of suction nozzles 5, for example, when the suction nozzle 5 is replaced with a suction nozzle having a smallest air suction port for suctioning a very small component, as shown in FIG. The opening / closing valve 25 of the passage 23 is closed and the opening / closing valve 26 of the second suction passage 24 is opened.

By switching the opening and closing of the on-off valves 25 and 26 in this manner, air is sucked into the adsorption nozzle 5 by an amount of air regulated by the throttle 28 of the second suction passage 24. Since the throttle 28 has a smaller air flow rate than the throttle 27 of the first suction passage 23, the suction nozzle has a larger diameter than that of the suction nozzle as compared with the suction nozzle. The air sucked into 5 decreases, and the pressure in the nozzle in the nozzle open state becomes relatively high (vacuum pressure is low).

Therefore, although the diameter of the air suction port of the suction nozzle 5 is small, the pressure difference between the pressure inside the nozzle in the nozzle open state and the pressure inside the nozzle in the nozzle suction state should be large. Will be able to. This differential pressure is indicated by the symbol P2 in FIG. In FIG. 8, a two-dot chain line shows a pressure change when the same suction nozzle is used in a conventional surface mounter. As can be seen from the figure, the differential pressure (P3) has been reduced in the past, whereas in the surface mounter 1 according to this embodiment, a case where an adsorption nozzle with a large air suction port is used is used. Equivalent differential pressure is now occurring.

As shown in FIG. 9, the vacuum generator 22 formed of an ejector has a substantially constant intake air amount even when the pressure of the pressurizing source changes, and uses the first suction passage 23.
When the second suction passage 24 is used, the throttles 27, 2
The negative pressure acting on the downstream side of 8 becomes substantially equal. For this reason,
By adjusting the diaphragm amount by diaphragms 27 and 28,
The differential pressure P1 and the differential pressure P2 can be set to be substantially equal. Since the two differential pressures P1 and P2 are substantially equal to each other, the use condition of the vacuum pressure sensor 32 can be made substantially constant when the control device 31 determines the presence or absence of suction and detects the cleaning time.

Of the three kinds of suction nozzles 5, when the suction nozzle 5 having the largest air suction port is used, or when a large gap is formed between the suction surface and the mounting component 8, intake air leakage is prevented. When using a large number of suction nozzles 5, as shown in FIG. 5, both the opening / closing valve 25 of the first suction passage 23 and the opening / closing valve 26 of the second suction passage 24 are opened. By opening the on-off valves 25 and 26 in this manner, the intake air flow rate of the suction nozzle 5 can be increased even if the suction nozzle 5 has a large diameter.

Therefore, even when such a suction nozzle 5 is used, the pressure inside the nozzle in the nozzle open state does not become excessively high (vacuum pressure becomes excessively low).
The differential pressure between the pressure inside the nozzle in the nozzle open state and the pressure inside the nozzle in the nozzle open state can be made as large as when using the other two types of suction nozzles 5. As a result, the use conditions of the vacuum pressure sensor 32 become substantially the same among the three kinds of suction nozzles 5, so that the control device 31 can accurately determine the presence or absence of suction.

Therefore, in the surface mounter 1 according to this embodiment, the first suction passage 23 and the second suction passage 24 are arranged in parallel on the downstream side of the vacuum pressure sensor 32 in the suction system of the suction nozzle 5. Since the opening / closing valves 25 and 26 and the throttles 27 and 28 are provided in these two suction passages, the suction valves 5 and Two suction passages
Air can be sucked into the suction nozzles 3 and 24 to relatively reduce the pressure inside the nozzles, and one of the on-off valves 25 and 26 is closed (the number of open on-off valves is reduced), whereby the adsorption nozzle 5 The intake air flow rate is reduced, and the pressure in the nozzle can be relatively increased.

For this reason, when the suction nozzle 5 is replaced with a nozzle having a relatively small air suction port, the number of open / close valves 25 and 26 that are open is reduced so that the inside of the nozzle in the nozzle suction state is reduced. The pressure difference between the pressure and the pressure inside the nozzle when the nozzle is open can be increased. As a result, even when the suction nozzle 5 is replaced with a suction nozzle 5 having a relatively small air suction port, the range of pressure detected by the vacuum pressure sensor 32 can be widened. The single vacuum pressure sensor 32 can accurately detect the cleaning time.

Further, the throttle 27 of the first suction passage 23
And the throttle 28 of the second suction passage 24 has different air flow rates, and the suction system is configured to suck air at an air flow rate that matches the diameter of the air suction port of the suction nozzle 5. can do. That is, when using the suction nozzle 5 having a relatively large air suction port, the first suction passage 2 having a relatively large air flow rate is used.
3 is opened, and when the adsorption nozzle 5 having a relatively small diameter is used, the opening / closing valve 26 of the second suction passage 24 in which the air flow rate is relatively small is opened to open the nozzle. The pressure difference (P1, P2) between the pressure inside the nozzle in the suction state and the pressure inside the nozzle in the nozzle open state can be made substantially equal even if the suction nozzle 5 is replaced.

Furthermore, when two suction passages are provided as in this embodiment, the throttles 27 and 28 for each suction passage are provided.
By using air flow rates different from each other, the case where only the first suction passage 23 is used and the second suction passage 23 is used.
Therefore, it is possible to take three forms, that is, the case where only the suction passage 24 is used, and the case where both of these suction passages 23 and 24 are simultaneously used.
There is also the advantage that can be used.

In this embodiment, an example in which the throttles 27 and 28 are provided in both the first and second suction passages 24 has been shown. However, in order to increase the intake air flow rate, the first suction passages are required. The diaphragm 27 does not have to be provided at 23. Even when this configuration is adopted, the three types of suction nozzles 5 can be replaced and used. Note that FIG. 8 will be described in terms of pressure drop. In the nozzle open state, the ratio of the pressure drop at the air suction port to the total pressure drop amount is small in the case where the diameter of the air suction port is large, and the upstream side passage 29, the suction passage 23, or the suction passage 24 is correspondingly small. Easy to be affected by pressure drop. That is, the pressure at the mounting position of the vacuum pressure sensor 32 is affected by the pressure drop in the passage, and the vacuum pressure (= negative pressure pressure) increases. Since the vacuum pressure detected by the vacuum pressure sensor 32 in the nozzle suction state is substantially the maximum negative pressure, the differential pressure becomes P3.

On the other hand, in the nozzle open state, when the throttle is arranged downstream of the vacuum pressure sensor 32 in the case where the air suction port has a large diameter, the ratio of the pressure drop at the air suction port to the total pressure drop amount is small. On the other hand, since the rate of pressure drop at the throttle is large, the amount of pressure drop at the mounting position of the vacuum pressure sensor 32 is correspondingly small, and the detected pressure is close to atmospheric pressure (vacuum pressure is small). Therefore, the differential pressure between the detected vacuum pressure in the nozzle suction state and the detected vacuum pressure in the nozzle open state is P2.

(Second Embodiment) As the throttle, one having the same air flow rate for each suction passage can be used.
An embodiment having such a configuration will be described with reference to FIGS. 10 to 12 are views showing another embodiment in which a plurality of suction passages are formed by one type of throttle, and FIG. 10 shows a state in which an adsorption nozzle having a relatively large air suction port is used. FIG. 11 shows a state in which an adsorption nozzle having a relatively small air suction port is used, and FIG. 12 shows a state in which positive pressure is applied. In these figures, the same or equivalent members as those described with reference to FIGS. 1 to 9 are designated by the same reference numerals and detailed description thereof will be appropriately omitted.

The suction device 41 shown in FIGS. 10 to 12 has a diaphragm 27 of the first suction passage 23 and a second suction passage 24.
Is the same as the diaphragm 28 of the first suction passage 2
The air flow rate at 3 and the air flow rate at the second suction passage 24 are formed to be substantially equal. In the adsorbing device 41 configured as described above, when the adsorbing nozzle 5 having a relatively large air suction port is used, FIG.
As shown in FIG. 2, the on-off valve 2 of both suction passages 23, 24
Open 5 and 26 respectively. Further, when using the suction nozzle 5 having a relatively small air suction port,
This is performed by closing either one of the two open / close valves 25 and 26. For example, at this time, as shown in FIG. 11, the opening / closing valve 26 of the second suction passage 24 is closed.

By reducing the number of suction passages in this manner, the flow rate of intake air in the adsorption nozzle 5 is reduced and the pressure in the nozzle is relatively increased. Therefore, when the suction nozzle 5 having a relatively small air suction port is used,
Since the differential pressure can be made large when the suction nozzle 5 having a relatively large diameter is used, the controller 31 in the above two modes can be used in spite of the single vacuum pressure sensor 32. Will be accurately determined and detected.

When positive pressure is applied to the suction nozzle 5 after the mounting component 8 is placed on the printed wiring board, both opening / closing valves 25 and 26 are closed as shown in FIG.
This is performed by opening the on-off valve 35 of the positive pressure supply passage 33. When a plurality of suction passages are provided as shown in this embodiment, the number of types of the diaphragms 27 and 28 is set to one, so that the structure of the suction device 41 is simplified and the assembling work and maintenance are facilitated.

In the above-mentioned first and second embodiments, for the sake of convenience of explanation, an example in which the on-off valves 25, 26, 35 are each constituted by an independent solenoid valve has been shown, but the type of on-off valve is not limited to this. It can be changed as appropriate. That is, for example, a valve in which a valve body that is switched to three positions by one actuator is integrally formed may be used. Further, although the throttles 27 and 28 are variable throttles in the above-mentioned embodiment, they may be fixed throttles, and in addition to using throttles formed as such components, the on-off valve 2
The throttle may be configured by changing the air passage diameter or length of the pipeline having 5, 26 and making the entire pipeline substantially function as the throttles 27, 28.

Further, the on-off valves 25 and 26 and the throttle 2
Although 7, 28 are provided in the head unit 15 in the first and second embodiments, the positions where these members are provided can be changed as appropriate. For example, the on-off valves 25 and 2
6 and the diaphragms 27, 28 can also be provided in the housing of the vacuum generator 22. By providing the head unit with the on-off valves 25, 26 and the throttles 27, 28 as shown in the first and second embodiments, the suction passage 2
It is possible to improve the responsiveness when switching between 3 and 24.

Furthermore, the vacuum generator 22 is not limited to the ejector, and may be a positive displacement or centrifugal air pump or another pressure reducing device as long as the intake air flow rate does not fluctuate significantly. Can be used. In addition, as shown in the first and second embodiments, in addition to connecting all the suction passages 23 and 24 to one vacuum generator 22, the same number of vacuum generators 22 as the suction passages are provided. Alternatively, the vacuum generator 22 may be provided and the vacuum generator 22 may be connected to each suction passage.

[0059]

As described above, according to the present invention, when the suction nozzle is replaced with an air suction port having a relatively small diameter, the number of open / close valves opened is reduced to thereby open the nozzle. Since the pressure in the nozzle in the state is relatively high, the pressure difference between the pressure in the nozzle suction state and the pressure in the nozzle open state can be increased. Therefore, even if the suction nozzle is replaced with a suction nozzle having a relatively small diameter, the range of pressure detected by the vacuum pressure sensor can be widened. It becomes possible to accurately perform the detection and the like with a single vacuum pressure sensor. As a result, it is possible to provide a highly reliable surface mounter while reducing costs.

According to the second aspect of the invention, since the suction system can be configured to suck the air at an air flow rate that matches the diameter of the air suction port of the suction nozzle, the inside of the nozzle in the nozzle suction state Even if the suction nozzle is replaced, the pressure difference between the pressure of 1 and the pressure inside the nozzle in the nozzle open state can be made substantially equal. Therefore, the presence / absence of adsorption and the detection of the cleaning time can be performed more accurately.

According to the third aspect of the present invention, when a plurality of suction passages are provided, only one kind of diaphragm can be used, so that the structure is simplified and the assembling work and maintenance are facilitated. Therefore, it is possible to provide a surface mounter with low manufacturing cost and running cost.

[Brief description of drawings]

FIG. 1 is a plan view of a surface mounter equipped with a suction nozzle according to the present invention.

FIG. 2 is a front view of a surface mounter equipped with a suction nozzle according to the present invention.

FIG. 3 is a configuration diagram showing a state in which an adsorption nozzle 5 having a relatively large air suction port is used.

FIG. 4 is a configuration diagram showing a state in which an adsorption nozzle 5 having a relatively small air suction port is used.

FIG. 5 is a configuration diagram showing a state in which the suction nozzle 5 having the largest air suction port diameter is used.

FIG. 6 is a configuration diagram showing a state in which positive pressure is applied.

FIG. 7 is a graph showing changes in pressure inside the nozzle.

FIG. 8 is a graph showing changes in pressure inside the nozzle.

FIG. 9 is a graph showing a flow rate characteristic of intake air of an ejector.

FIG. 10 is a configuration diagram showing a state in which an adsorption nozzle having a relatively large air suction port is used.

FIG. 11 is a configuration diagram showing a state in which a suction nozzle having a relatively small air suction port is used.

FIG. 12 is a configuration diagram showing a state in which positive pressure is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Surface mounter, 5 ... Suction nozzle, 6,41 ... Suction device, 8 ... Mounting component, 22 ... Vacuum generator, 23 ... First suction passage, 24 ... Second suction passage, 25, 26 ... Open / close valve, 27, 28 ... Restrictor, 32 ... Vacuum pressure sensor.

Claims (3)

[Claims] 1. A surface mounting machine in which a suction nozzle for picking up a component is provided in a replaceable manner according to the type of mounting component, and a pressure on the downstream side of the suction nozzle is detected by a sensor. A plurality of suction passages are connected in parallel on the downstream side of the sensor in
A surface mounter characterized in that an opening / closing valve and a throttle are provided in these passages. 2. The surface mounter according to claim 1, wherein the throttle has a different air flow rate at a predetermined pressure difference for each suction passage. 3. The surface mounter according to claim 1, wherein the throttle has an equal air flow rate at a predetermined pressure difference for each suction passage.