GB2155212A

GB2155212A - Apparatus for assembling component parts

Info

Publication number: GB2155212A
Application number: GB08504834A
Authority: GB
Inventors: Paul Radmall
Original assignee: DOWTY GROUP SERVICES
Current assignee: DOWTY GROUP SERVICES
Priority date: 1984-02-29
Filing date: 1985-02-25
Publication date: 1985-09-18
Also published as: GB8504834D0

Abstract

An apparatus for assembling component parts includes a first device 4 (e.g. a robot arm) having a computer 3 programmed to move a first component part 13 (figs. 2-4, not shown) from one predetermined position in space to another predetermined position in space at which it is to be assembled with an aligned second component part (7), a clamping device (12) for holding one of the component parts (13) in a fixed position with respect to the other component part, a second device (9), independent of the first device, for operating on the non-clamped component part (7) to assemble the component parts, and a system control computeri programmed to (a) determine the operation of the program of the computer of the first device 4, and (b) control operation of the clamping device (12) and the second device (9). <IMAGE>

Description

SPECIFICATION Apparatus for assembling component parts This invention relates to apparatus for assembling component parts.

According to this invention an apparatus for assembling component parts includes a first device having a computer programmed to move a first component part from one predetermined position in space to another predetermined position in space at which it is to be assembled with an aligned second component part, a clamping device for holding one of the component parts in a fixed position with respect to the other component part, a second device, independent of the first device, for operating on the non-clamped component part to assemble the component parts, and a system control computer programmed to (a) determine the operation of the program of the computer of the first device, and (b) control operation of the clamping device and the second device.

The first device may be a robot and may move both component parts, for example one after the other, into their aligned positions.

When the first device moves both component parts to their aligned positions, it may retain the second component part in its aligned position.

That part of the first device which is retaining the second component part may be held by the clamping device. In this case, the clamping device could be two or more pegs which engage in appropriate holes or channeis in the aforementioned part of the first device.

When the two component parts are assembled by means of screw-threads, the second device may be a spanner capable of being rotated, for example by a motor.

The system control computer may also be used for other purposes, for example monitoring the system, presenting management information and controlling data transfer to and from the system.

By employing a system control program which controls the operation of the second device and which determines the operation of the first device, the latter, the computer associated with it and its appropriate computer program, can be of a relatively simple nature.

The computer program of the first device may comprise a plurality of subsidiary programs, each of which will be brought into operation at an appropriate time by the system control computer. For example, seeing that the locations of component parts in a store of like component parts will not be the same, some of the subsidiary programs will ensure the first device moves to correct positions of the store to remove component parts as and when they are required.

An embodiment of the invention given by way of example of the invention will now be described with reference to the accompanying drawings. In this embodiment the two component parts are assembled by co-operating screw-threads.

Figure 1 is a sketch showing the apparatus, Figure 2 is a sketch showing the certain parts of the apparatus, Figure 3 is a sketch of two component parts of the assembly prior to being assembled together, and Figure 4 is a sketch of the two component parts after assembly.

Referring to the accompanying drawings, the apparatus includes a system control computer 1 suitably programmed to control the operation of an assembly tool 2 and to determine the operation of the program of a robot computer 3. A robot 4 includes an arm 5 which, is caused to move, in accordance with the program of the robot computer, in two directions which are at right angles the one to the other. The arm has a gripper 6 which is caused to be operated in accordance with the program of the robot computer 3. The operation is such as to grip a first component part 7 in a store 8 of such component parts, and to transfer that component part 7 to another predetermined position in space, at which position it is delivered to a part of the assembly tool 2.

The assembly tool 2, see Figure 2, includes a spanner insert 9 which is rotatable by say, an electric motor and gear box 10, and which can be moved axially by a piston-and-cylinder device 11 such as an air cylinder. The assembly tool 2 also includes a clamping tool 12 such as a vice for gripping the second component part 13 which is to be assembled with the first-mentioned component part 7. The robot 4 may, after it has delivered the first-mentioned component part 7 to the assembly tool 2, be moved to a store of the second-mentioned component parts 14, parts 14, whereupon it grips a second-mentioned component part 13 to a predetermined position in space where the two component parts 7 and 13 are substantially aligned (see Figures 3 and 4).

In operation, the program of the system control computer 1 will first cause operation of the program of the robot computer 3. The robot arm 5 will be caused to move to grip a first component part 7 from the appropriate store 8, and to transfer the gripped first component part 7 to that predetermined position in space where it will be housed within the spanner insert 9. The robot arm 5 will then be caused to move to the store of second component parts 14, to grip a second component part 13 and to transfer it to a predetermined position in space. In such position it will be substantially aligned with, but spaced apart from, the first component part 7 housed within the spanner insert 9.

The robot will then be caused accurately to position the second component part 13 on the screwthread of the first component part 7. During this time, the system control computer will cause energisation of the air cylinder so that the robot 4 is acting against the effort of the energised air cylinder 11.

The system control computer 1, when it has sensed the correct position of the screw-thread of the second component part 13 against the screwthread of the first component part 7, will cause the motor 10 to rotate the spanner insert 9 and, hence, to rotate the first component part 7 in the reverse direction to the screw-thread of the second component part 13. When the "start-point" of one of the two screw-threads passes the "start-point" of the other there will be a momentary vertical acceleration of one part and this will be registered by a "click" sensor 15 attached to the air cylinder 10.

The "click" sensor 15 will send an appropriate signal to the system control computer 1, whereupon the following will occur: (a) the direction of rotation of the motor 10 is reversed, and (b) a counter (not shown) for counting the number of turns is actuated.

As the motor 10 is caused to rotate the two component parts 7 and 13 are screw-threaded together, the number of turns being counted. After about one turn, the jaws of the clamping tool 12 will be caused by the system control computer to close, thereby to grip the second component part 13. The second component part is still maintained in its correct spatial position by the gripper 6.

When an appropriate number of turns has been counted, the system control computer 1 will cause the torque of the motor 10 to be adjusted to such a value that subsequent rotation of the motor 10 will cause the two component parts 7 and 13 to be assembled to the correct torque.

When the two component parts 7 and 13 have been assembled to the required torque, the jaws of the clamping tool 12 will be caused to open, and the robot 4 will be caused to remove the assembled component parts and to transfer them to a store of assembled component parts (not shown).

The operation just described will continue until all the component parts in the two stores to be assembled have been dealt with.

The operation just described has been concerned with the assembly of two aligned component parts.

In another embodiment of the invention three aligned component parts may be assembled. The operation will be somewhat the same as that already described, except in this case, when the jaws of a clamping tool have gripped a second component part, the robot will move away to a store of third component parts. It will pick up a third component part and convey it to a predetermined position aligned with the first two component parts which are being assembled so that, when the first two component parts have been assembled, the third component part can be assembled, by means, for example, of another spanner insert of another second drive. In addition, the robot gripping device may be changed under the control of the system computer.

If, during a lengthy cycle of assembly, it is necessary to assemble components of one kind and then components of another kind, the program of the robot computer can be such that, prior to fetching the first component parts in the cycle of a certain kind, it can insert into the assembly tool (and remove, when necessary) a spanner insert of a kind appropriate to that certain kind of component parts. These can be held in a tool store 16 (see Figure 1).

In the embodiments described above, the two mating component parts have been assembled by way of screw-threads. In other embodiments of the invention they may be assembled in other ways, for example, one may be a push-fit within the other. In that case, rather than having a rotary spanner insert, a device for forcing one member axially into the other will be employed.

Claims

1. An apparatus for assembling component parts including a first device having a computer programmed to move a first component part from one predetermined position in space to another predetermined position in space at which it is to be assembled with an aligned second component part, a clamping device for holding one of the component parts in a fixed position with respect to the other component part, a second device, independent of the first device, for operating on the non-clamped component part to assemble the component parts, and a system control computer programmed to (a) determine the operation of the program of the computer of the first device, and (b) control operation of the clamping device and the second device.

2. An apparatus as claimed in claim 1 in which the first device is a robotic device.

3. An apparatus as claimed in either claim 1 or claim 2 in which the first device moves both the second component part and the first component part to their respective aligned positions.

4. An apparatus as claimed in any one of the preceding claims in which the computer program of the first device comprises a plurality of subsidiary programs, each one of which is brought into operation at an appropriate time by the system control computer.

5. An apparatus for assembling component parts substantially as hereinbefore described and with reference to the accompanying drawings.