GB2340421A

GB2340421A - Machine tool system with improved connection means

Info

Publication number: GB2340421A
Application number: GB9817891A
Authority: GB
Inventors: Kenneth William Young
Original assignee: MG Rover Group Ltd
Current assignee: MG Rover Group Ltd
Priority date: 1998-08-18
Filing date: 1998-08-18
Publication date: 2000-02-23
Also published as: GB9817891D0

Abstract

A machine tool system is disclosed in which a plurality of workstations 12,14,16 are connected to a control unit 18 using plug and socket connections 22/42,24/44,26/46. The plugs 50 have less than ten, and preferably five, connecting pins 51-55 for the transfer of all of the control signals between the machine tools and the control unit. This is preferably achieved using field bus technology, so that there is no loss in operating speed. These connecting pins are robust and less likely to break than previous plug connections; however, if one of the pins does become damaged, it is a relatively simple matter to determine which of the connections is damaged. The plug and socket connections are preferably connected together and drawn apart by hydraulic or pneumatic means 32,34,36.

Description

2340421 - 1 Tooling AD1)aratus The present invention relates to an

improved tooling apparatus. The invention has particular, but not exclusive, application to a tooling apparatus of the kind in which a plurality of machine tools installed along a production line are controlled by a single control unit.

There are a number of problems with known systems of the kind set forth. For example, in some known systems each of the machine tools is individually wired up to the control unit. Should one of the connections between the machine tools and the control units cease to function, the identification of the particular connection at fault is a very difficult and time consuming task.

In an alternative known system, each machine tool is releasably connected to the control unit. In such systems each of the required control signals is provided with a connection to the control unit. This may result in a connection between a machine tool and the control unit comprising a plug and socket connection having a large number, twenty or thirty, of pins.

Each of the pins will be of a small size in order to fit into the space provided on the plug.

However, because of their small size the pins will not be particularly robust and a great deal of care will be necessary in order to prevent any of the pins becoming damaged on repeated connection and disconnection of the plug. Further, should one of the connections between a machine tool and the control units cease to function, the identification of the particular connection at fault is remains a difficult and time consuming task.

Accordingly, there is a need for a system providing control of a plurality of machine tools from a single control unit, in which the control unit can repeatedly be releasably connected to each of the machine tools in a quick and convenient manner without the connection between each machine tool and the control unit becoming damaged.

According to the present invention, a machine tool system comprising a control unit and a plurality of machine tools in which the machine tools are connected to the control unit by a multiplexing system characterised in that the or each machine tool is connected to the control unit by a socket disposed therebetween having less than ten connecting pins to provide all of the control signals between the or each machine tool and the control unit.

Preferably, the connecting pins in the socket are five in number. This can be achieved by the use of Fieldbus technology without a loss in processing speed. This has the advantage that robust connecting pins can be used. This in turn means that each machine can be connected to and released from the control unit many thousands of times over the life of the system. Further, if one of the connecting pins does become damaged it is a relatively simple matter to determine which of the connections is damaged.

Preferably, the socket disposed between the or each machine tool and the control unit is connected together and drawn apart by hydraulic or 5 pneumatic means.

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

Figure 1 shows a schematic view of a machine tool system in accordance with the present invention; and Figure 2 shows a perspective view of a plug and socket suitable for connecting a machine tool to a control unit in accordance with the machine tool system of the present invention.

Referring first to. Figure 1 there is shown in schematic form a machine tool system 10 in accordance with the present invention. First, second and 15third workstations 12,14,16 are disposed about a conveyor 20. A workpiece (not shown) is be adapted to move along the conveyor 20 to be worked upon at the first, second and third workstations 12,14,16 by various machine tools.

Each of the machine tools at the workstations 12,14,16 are adapted to be controlled by a single control unit 18. Each of the workstations 12,14, 16 includes a part of a plug and socket connection, usually the socket 22,24, 26.

The control unit 18 is connected to first, second and third pneumatic drivers 32,34,36 along a single control bus 40. First, second and third connections to the control bus 40 are shown 33,35,37. Each of the first, second and third pneumatic drivers 32,34,36 includes a complimentary part of the plug and socket connection, usually the plug 42,44,46.

Referring to Figure 2, each of the plug and socket connections comprises a plug 50 and a socket 60 as noted above. The plug conveniently comprises five pins 51,52,53,54,55. The pins are conveniently arranged in a regular pattern on a head 58 of the plug 50. The socket comprises a number of recesses 61,62,63,64,65 in a head 68 of the socket 60 adapted to receive the pins of the plug.

As the workpiece reaches a particular workstation, the presence of the workpiece is identified using any convenient means. For example, in Figure 1, when the workpiece arrives at the second workstation 14 a signal is sent to the control unit 18. On receipt of this signal, a further signal is generated and sent along the control bus 40 to the second pneumatic driver 34 to drive the plug 44 into the socket 24 of the second workstation 14, in order to connect the second workstation 14 to the control unit 18.

Once the operation to be conducted at the second workstation has been completed, a final signal is sent to the control unit 18. The control unit then sends a last signal to the pneumatic driver 34 along the control bus 40 to retract the plug 44 from the socket 24 of the second workstation 14, in order to disconnect the second workstation 14 from the control unit 18. The second workstation 14 is now ready to repeat the cycle on the arrival of a further workpiece at the second workstation 14.

Claims

-6CLAIMS

1. A machine tool system comprising a control unit and a plurality of machine tools in which the machine tools are connected to the control unit by a multiplexing system characterised in that the or each machine tool is connected to the control unit by a plug and socket assembly disposed therebetween having less than ten connecting pins to provide all of the control signals between the or each machine tool and the control unit.

2. A system according to claim 1, characterised in that the connecting pins in the plug and socket assembly are five in number.

3. A system according to claim 1 or claim 2, characterised in that the multiplexing system used is Fieldbus.

4. A system according to any previous claim, characterised in that the plug and socket assembly disposed between the or each machine tool and the control unit is connected together and drawn apart by hydraulic or pneumatic means.

5. A substantially as described herein with reference to and as illustrated in the accompanying Figures.