WO2000016602A1

WO2000016602A1 - A method of supplying components to an electronic component mounting or insertion machine

Info

Publication number: WO2000016602A1
Application number: PCT/SG1998/000070
Authority: WO
Inventors: Cheng Sheng Chai; Masashi Miyake; Beng Yew Vincent Mak; Boon Hai Teo
Original assignee: Matsushita Technology (S) Pte Ltd
Priority date: 1998-09-10
Filing date: 1998-09-10
Publication date: 2000-03-23
Also published as: CN1250064C; CN1281631A

Abstract

A method is disclosed for supplying components to an electronic component mounting or insertion machine, the machine having first and second component supply tables each having a plurality of component supply units, the method comprising steps of: (a) supplying components to be mounted from the supply units to a component mounting device in a predetermined order; (b) sensing for exhaustion of a component from a supply unit of one said table; and (c) continuing with the supply of subsequent components from the other said table while said one table is moved to a replenishment station. Other features are disclosed which allow the machine to continue to supply subsequent components from the table containing the exhausted component prior to replenishment and for skipping components to be taken from a table that is being replenished and inserting the skipped components subsequently.

Description

A METHOD OF SUPPLYING COMPONENTS TO AN ELECTRONIC COMPONENT MOUNTING OR INSERTION MACHINE

FIELD OF THE INVENTION

The present invention relates to a method of operation of an electronic component mounting or insertion machine, more particularly to a component supply method using a component supply apparatus provided with a plurality of supply tables adapted to move independently.

BACKGROUND OF THE INVENTION

The conventional component supply method used in an electronic component mounting or insertion machine for mounting or inserting electronic components to a printed basic plate will be described with reference to Figs. 1 - 4.

Fig. 1 shows one example of an electronic component mounting or insertion machine. The electronic component mounting or insertion machine is composed of a main body 1 and a component supply apparatus 2. The main body 1 includes a printed basic plate supporting apparatus 3, a rotary mounting or insertion head 4 and so on. The component supply apparatus 2 is composed of a left supply table 6 and a right supply table disposed to be freely movable on a guide rail 5.

A plurality of component supply units 8 are set respectively on the supply tables 6 and 7, with the electronic components being loaded on separate component supply units 8 according to the type of component. The supply tables 6 and 7 are independently movable reciprocatingly on a guide rail 5. The supply table 6 or 7 is moved so that the component supply unit 8 having a required type of electronic component loaded therein is positioned at a component supply position 9 so as to effect a component supply operation.

An electronic component is extracted by the rotary mounting or insertion head 4 at the component supply position 9 and is carried to a printed basic plate supporting apparatus 3 by operation of the rotary mounting or insertion head 4. Thereafter, the electronic component is mounted onto the printed basic plate.

Fig. 2 illustrates an embodiment of the component supply apparatus 2. A screw 10 is disposed and secured along its moving direction under the supply tables 6 and 7. A nut portion 11 to be screwed onto the screw shaft 10 and a motor 12 with the nut portion 11 being rotary driven around the screw shaft 10 are provided for each supply tables 6, 1 .

The motor 12 has a cylindrical rotor 14 disposed concentric to the screw shaft 10 within a stator 13 secured on the under face of the supply tables 6 and 7, and is rotationally supported through a bearing 15. One end portion of the rotor 14 is coupled to a nut portion 11. Accordingly, the motor 12 rotates the rotor 14 so as to rotate the nut portion 11 so that the supply tables β and 7 are respectively reciprocated independently along the guide rail 5.

When numerous types of electronic components are to be used in the production of the required printed basic plates, the component supply units 8 are distributed and loaded on both the left supply table 6 and the right supply table 7. In this case, the respective supply tables 6 and 7 must be alternately moved to the component supply position 9 in accordance with the electronic components to be mounted. A first and a second component supply method employing the alternate use of such supply tables 6 and 7 will now be described.

The first component supply method entails moving only a supply table to be used while the other supply table not used is stopped in respective waiting position. Fig. 3(a) shows a condition where the left supply table 6 is used. The right supply table 7 not used moves to a waiting position 17 and is in a stop condition until such time the right supply table is used again. Fig. 3(b) shows a condition in which the right supply table 7 is selected for use. The not needed left supply table 6 moves to a waiting position 16 and enters a stop condition. The right supply table 7 moves to a component supply position 9.

A second component supply method entails operating both of the supply tables 6 and 7 similarly regardless of which of the supply tables 6 and 7 is being used. Fig. 4(a) shows where the right supply table 7 has been selected and Fig. 4(b) where the left supply table has been selected. In either case, both supply tables 6 and 7 behave as one supply table by moving together the same distance in the same direction while retaining the required interval therebetween.

In the method shown in Fig. 3, the supply table must move from the waiting position to the component supply position upon selection of the supply table, whereby the component supply operation is interrupted which wastes time and lowers productivity. Generally, the waiting position is spaced a sufficient distance from the component supply position so as to avoid interference with the movement of the other supply table, thus resulting in a large amount of wasted time each time a supply table is made to move across this distance.

In the method of Fig. 4, movement to and from a waiting position is not necessary upon selection of a supply table, thus resulting in a reduced consumption of time when switching over between supplying table. However, in contrast to the method of Fig. 3 in which one supply table is to be moved by the supply of the electronic components, in the method of Fig. 4, two supply tables are moved simultaneously which can cause greater mechanical vibration. Referring again to the component supply apparatus of Fig. 3, vibrations caused by the driving operations of the motors 12 are transmitted to the screw shaft 10. When the two supply tables 6 and 7 are simultaneously moved the two motors 12 are simultaneously driven so as to cause large vibrations in the screw shaft 10. The vibrations of the screw shaft 10 are transmitted to the supply tables 6 and 7 mounted thereon so as to vibrate the component supply unit 8 and the electronic components loaded therein. As a result, the rotary mounting or insertion head 4 suffers a reduced success ratio in the engagement of the components which in turn deteriorates the production efficiency by increasing time consumption for the repairs and wasting electronic components. Also, the electronic components mounting or insertion accuracy is deteriorated due to the vibrations of the entire machine.

Accordingly, it is an object of the invention to alleviate the above discussed drawbacks inherent in the prior art.

SUMMARY OF THE INVENTION

According to the invention in a first aspect, there is provided a method of supplying components to an electronic component mounting or insertion machine, the machine having first and second component supply tables each having a plurality of component supply units, the method comprising steps of :

(a) supplying components to be mounted from the supply units to a component mounting device in a predetermined order;

(b) sensing for exhaustion of a component from a supply unit of one said table; and

(c) continuing with the supply of subsequent components from the other said table while said one table is moved to a replenishment station.

Preferably the method further comprises the step of continuing with the supply of subsequent components from said one table before step (c) , more preferably until a component from said other table is to be inserted.

Preferably the method further comprises the step of, when said one table is being replenished, skipping the insertion of components from that table and inserting those components after replenishment and more preferably continuing to insert components from said other table after the components from said one table have been skipped.

According to the invention in a second aspect, there is provided a method of supplying components to an electronic component mounting or insertion machine, the machine having first and second component supply tables each having a plurality of component supply units, the method comprising steps of :

(c) continuing with the supply of subsequent components from said one table before moving said one table to a replenishment station.

Preferably the method further comprises the step of continuing the supply of subsequent components from said one table until a component from said other table needs to be inserted.

According to the invention in a third aspect, there is provided a method of supplying components to an electronic component mounting or insertion machine, the machine having first and second component supply tables each having a plurality of component supply units, the method comprising steps of :

(b) sensing for exhaustion of a component from a supply unit of one said table and moving that table to a replenishment station; and

(c) continuing with the supply of subsequent components and skipping the insertion of components from said one table and inserting those components after replenishment.

In the described embodiment of the present invention, whenever a component supply unit on a component supply table at a component take out position is exhausted, the extraction operation will continue on the succeeding component supply unit on the component supply table following the instructions from the production program. Upon the switching over of the component supply tables, the table that has an exhaustion on one of its component supply units will move out to the designated position to allow for component supply unit replenishment. At the same time during the component supply unit replenishment of a particular table, the switched component supply table will continue the component extraction operation. After the component supply replenishment process to the component supply unit on the particular component supply table has been completed, the extraction for the previously exhausted component supply unit will begin once the switched component supply table has completed its extraction program. The insertion of components to the end of one table after exhaustion of a component has been sensed reduces the traverse distance between the tables, thereby minimising the overall exchange time. Using the replenishment time for one table to continue insertion with the other interrupts the main machine extraction operation to a lesser degree thereby reducing the wastage of time and increasing the machine's overall productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings in which:

Fig. 1 is a plan view showing the construction of an electronic components mounting or insertion machine;

Fig. 2 is a partional sectional front view showing the construction of a component supply apparatus;

Figs. 3(a) and 3(b) are views illustrating a first component supply method of the prior art;

Figs. 4(a) and 4(b) are views illustrating a second component supply method of the prior art;

Fig. 5 is a flow chart illustrating a first component supply routine of an embodiment of the component supply method of the present invention;

Fig. 6 is a flow chart of a second component supply routine of the embodiment of Fig. 5;

Fig. 7 is a flow chart of a component replenishment routine of the embodiment of Figs 5 and 6;

Fig. 8 illustrates five possible component supply and replacement scenarios using the embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the component insertion method of the present invention will now be described with reference to Figs 5 -7. It will be appreciated that this method may be used with the prior art electronic component mounting or insertion machine previously described with reference to Figs. 1 and 2.

A feature of the embodiment of the present invention to be described is that if a table runs out of a particular component for insertion, the machine looks ahead in the list of components to be inserted and continues with those consecutive components if on the same table. When there are no more consecutive components on that table to be inserted, the table is placed to a waiting position for insertion of replacement components but, rather than the machine stopping at this point, if there are any components from the other table which can be inserted, these are then inserted thus using up some of the dead time while the table is being refilled. This action is performed similarly when the other table runs out of a particular component as will now be described, with reference to Figs 5 and 6.

The electronic component mounting or insertion machine shown in Figs. 1 and 2 is micro-processor controlled and programmed to insert a plurality of components into a printed basic plate. In this embodiment, each supply table 6, 7 is capable of storing sixty (60) components, components Zl - Z60 on supply table 6 and components Z61 - Z120 on supply table 7 each in a separate component supply unit. The order in which these components are taken from the component supply unit 8 mounted on the supply tables 6 and 7 is programmed into the machine, together with the position at which the components are inserted into the printed basic plate. A master program control the operation of the machine. For each cycle of insertion or mounting of components, the sub-routines shown in Figs. 5 and 6 are called.

With reference to Fig. 5, the routine starts at step 100 and at step 105, the designation of the first table is made. This can be either table 6 or table 7, depending on where the first component of the production run is located. The thus designated first table is then chosen for insertion at step 110. After insertion of the first component, a check is made as to whether or not that component has become exhausted. If not, at step 130 a check is made to see if the end of the insertion program for that PCB has been reached. If so the subroutine ends, returning to the master program. If not, at step 140 it is determined if the next component to be inserted is from the first table and if so, loops to step 110 for insertion of the next first table component.

If at step 120 it is determined that the component just inserted is exhausted, a check is made at step 200 if the next component is from the second table. If not, a check is made if the end of the insertion program for that PCB has been reached at step 210. If so, the first table is moved to a waiting position for replenishment at step 220, the routine then ending at step 150 as before. If not, the program loops to step 110 for insertion of the next first table component.

If at step 130, it is determined that the next component is not from the first table, a check is made at step 230 as to whether or not a component exhaust state has already been determined for the second table. If so, at step 240, the next second table component is skipped, as the second table in the waiting position for replenishment. The identity of the component is also saved at this point, for subsequent insertion once the second table has been replenished. A check is then made at step 250 if the next component is from the first table. If so, the routine loops to step 110 for component insertion. If not, a check is made at step 260 if the end of the insertion program for that PCB has been reached. If so, the routine ends at step 150 but if not, the routine loops back to step 240 at which the next second table component is skipped and saved. This continues until first table components are found at step 250 and/or the end of the insertion program has been reached at step 260.

If either at step 200 or steps 140 and 230 it is determined that the next component is a second table component the first and second tables are exchanged at step 270 with the first table being first moved to the waiting position for replenishment if necessary at steps 275, 280.

From step 270 the routine moves to a further routine shown in Fig. 6 in which at step 300, the second table is used for insertion. The routine in Fig. 6 operates in almost the same way as the routine in Fig. 5 and similar steps have been given similar reference numerals with the addition of 200.

The essential differences between the two routines are, firstly, that after insertion has finished at step 460, which corresponds to step 260, the second table is moved to the waiting position at step 500. Essentially, this step moves the second table out of the way to avoid crashing and interference with the first table, which has priority.

Secondly, at step 400, which corresponds to step 200, if the next component is a first table component a check is made as to whether or not the first table is already in an exhaust condition at step 430 and if so, a check is made at step 510 if the second table is already in an exhaust condition. If so, at step 520 the second table is moved to the waiting position and at step 530 a determination is made as to whether or not the insertion process has finished. If so, the routine ends at step 530 and if not, the first and second tables are exchanged at step 470.

Independently, a shown in Fig. 7, the waiting positions of the first and second tables and replenishment conditions of the component supply units are monitored. As shown in this flow chart, it is determined at loops 600, 610 if either of the first and second table is in the waiting position. If the first table is found in the waiting position, a check is made at step 620 to determine if the second table is also in the waiting position. If not, only the first table is monitored at step 630 to determine when replenishment is completed. When this has occurred, a check is made back on the second table at step 640 to determine if the second table has completed insertion (the steps of Fig. 6) . Once insertion has completed, the first table is moved back at step 650.

If at step 620 it is found that the second table is already in the waiting position , at steps 660 and 670 the first and second tables are checked one after the other to determine which is replenished first. That table is then moved back at steps 680 or 690 and then a determination is made if the other has yet been replenished at steps 700 or 710. Once this has been completed it is determined if the table that had already been moved back at steps 680 or 690 has completed insertion (Fig. 5 for the first table and Fig. 6 for the second table) at steps 720, 730 and then once inserted has been completed, the other table is moved back at steps 740 or 750 to commence insertion.

If in loop 600, 610 it is determined that the second table is in the waiting position as opposed to the first, steps 760, 770 and 780 are undertaken which are similar to steps 620 - 640 described above.

Once the replenished table has been moved back at step 650, 750, 740 or 780, the routine ends at step 790, returning to start 795 at which the positions of the first and second tables continue to be monitored as before.

Once a table has been replenished and moved, the master program will then call again the subroutine of Figs. 5 and 6 and insert the missing components which have been saved at steps 240 and 440.

Five simplified examples of operation of the present invention shown in Fig. 8 in which six components are due to be inserted by the machine into a printed basic plate in the order shown will now be described and in which components Zl- Z60 are located in respective component supply units on the supply table 6 and components Z61-Z120 are similarly located on the supply table 7. All examples commence with the master program calling the routine of Fig. 5.

In Case 1, table 6 is designated as the first table at step 105 as the first component to be inserted, Zl is on table 6, and Components Zl and Z30 are inserted via steps 110, 120, 130, 140. Component Z30 then becomes exhausted. Since component Z60 is on the first table and is not exhausted, this is inserted through loop 120, 130, 140, 110. However, the next component Z61 is on the second table so at step 120, the routine branches via step 200 to steps 275, 280 at which the first table is moved to a waiting position for replenishment of Z30 and the first and second tables are exchanged at step 270. The routine then passes to the flow chart of Fig. 6 at which component Z61 and Z80 are inserted.

Z80 then is exhausted. The next component, Z120, which is from the second table, is inserted via steps 320, 330, 340,

310. As component Z120 is the last component, the routine proceeds via steps 320, 400, 410, 420 at which the second table moves to the waiting position for replenishment of component Z80 and then the routine ends at step 350.

The first and second tables are then replenished in accordance with the routine of Fig. 7 and then the master program will replace the completed circuit board with a new one and call the routine of Fig. 5 again.

In Case 2, table 6 is designated as the first table, Component Zl is taken first and then, the tables are exchanged through steps 120, 130, 230, 275, 270. Z80 is taken and then becomes exhausted with the next component Z60 being on table 1. The routine passes back to the first table and the second table is moved to the waiting position for replenishment via steps 320, 400, 430, 510, 520, 530, 470. Z60 is inserted but the next component Z61 is on the second table. However, the second table has already moved to the waiting position for components to be inserted. Consequently, component Z61 is skipped and saved via steps 130, 230, 240 and component Z30, from the first table, is inserted at steps 250, 110. Z120, from the second table, is also skipped via steps 130, 230, 240 before the routine ends via steps 250, 260, 150. The second table is replenished and is then moved back to its operational position in accordance with the routine of Fig. 7. The master program then calls again the routine of Fig. 5 again, this time to insert the missing components Z61 and Z120. Since Z61 is on table 7, this table is now designated as the first table and components Z61 and Z120 are inserted by the steps 110, 120, 130, 140, 110, 120, 130 before ending at step 150.

In Case 3, table 6 is designated as the first table and components Zl and Z30 are inserted but component Z30 then becomes exhausted. Since the next component Z61 is on the second table, the first table is moved to the waiting position at step 280 and tables are exchanged at step 270. Control passes to the flowchart of Fig. 6 and Z61 is then inserted. Since component Z60 is from the first table but this table is currently being replenished with component Z30, component Z60 is skipped and saved through steps 320, 330, 430, 440 and components Z80, Z120 are then taken at step 450 and two cycles of steps 310 - 340, before ending at step 350. The first table, once replenished, reverts back to its operational position and then the master program calls the routine of Fig. 5 again, this time to insert the missing component Z60 via steps 110, 120, 130, 150.

In Case 4, table 6 is designated as the first table and both components Zl and Z30 are taken from the first table by loop 110 - 140 and then component Z61 is taken from the second table by steps 110, 120, 200, 275, 270,310 and becomes exhausted. Thus via steps 320, 400, 430, 510, 520, 530 and 470, the second table is moved to the waiting position and the second and first tables are exchanged. Then from Fig. 5, component Z60 is inserted and then also becomes exhausted. The first table is moved to the waiting position and the first and second table are exchanged again through steps 110, 120, 200, 275, 280, 270. The program then waits at step 310 until the second table is moved back to an insertion position using the routine of Fig. 7, before continuing to insert component Z80.

In Case 5, component insertion starts with table 7 being designated as the first table at step 105 since the first component Z61 is on table 7. Components Z61 and Z80 are inserted by loop 110, 120, 130, 140, 110 with component Z80 then becoming exhausted. The next component Z120 is also from the first table so this is taken through steps 120, 200, 210, 110. The next component Zl is on the second table, so the tables are exchanged, with the first table being moved to the waiting position for replenishment via steps 130, 140, 230, 275, 280, 270. The next component Z81 is from the first table, but since Z80 is currently being replenished and the first table is in the waiting position, component Z81 is skipped and saved and the final second table component Z60 is provided via steps 310, 320, 330, 340, 430, 440, 450, 310, 320, 330, 350. Once the second table has been replenished, this will move back to its operative position and the master program then calls the routine of Fig. 5 to complete insertion of component Z80.

It is to be understood that reference to the plural "components" in the following claims should be construed as referring equally to the singular "component".

Claims

1. A method of supplying components to an electronic component mounting or insertion machine, the machine having first and second component supply tables each having a plurality of component supply units, the method comprising steps of :

2. A method as claimed in claim 1 further comprising the step of continuing with the supply of subsequent components from said one table before step (c) .

3. A method as claimed in claim 2 further comprising the step of continuing the supply of subsequent components from said one table until a component from said other table is to be inserted.

4. A method as claimed in any one of the preceding claims further comprising the step of, when said one table is being replenished, skipping the insertion of components from that table and inserting those components after replenishment.

5. A method as claimed in claim 4 further comprising the step of continuing to insert components from said other table after the skipped components.

6. A method of supplying components to an electronic component mounting or insertion machine, the machine having first and second component supply tables each having a plurality of component supply units, the method comprising steps of :

7. A method as claimed in claim 6 further comprising the step of continuing the supply of subsequent components from said one table until a component from the other table needs to be inserted.

8. A method of supplying components to an electronic component mounting or insertion machine, the machine having first and second component supply tables each having a plurality of component supply units, the method comprising steps of :