programs for such operations as drilling and deep drilling carried out in stages.

How many mistakes have you done? What are they?

II. Find the words in the text and translate the word combinations with these words.

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III. Work in pairs. Study the prompts in italics concerning the Gerund and Participle I. Think of 2 or 3 sentences using the words from Ex. I.

V. Read the text and find the description to the picture above.

WORKPIECE TRANSFER TECHNOLOGY

Pallet is a device which serves as a standardized conveyance for the part in FMS; it may be an integral part of a cart.

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To turn a machining cell into FMS with low manning, mechanical handling devices are needed. Since the workpieces at machining centres are usually large and heavy, some form of pallet changing and handling is necessary. The machines are equipped with either a multi-station pallet carrier or an APC (automatic pallet changer). Many APCs are separate

Сunits, controlled by the CNC, but handling should be quicker and simpler with an integrated design.

The APC is available in many types ( pic. 27). These types are used depending on the requirements of machining centres (MCs) and other ma-

chines.

Robot type is used as an automatic workpiece changer (AWC), and supplies workpieces on a compact loop conveyor and uses a robot to load and unload the workpieces. It is known to be widely used for compact ma-

chining centres and NC lathes.

и Dual бtype is a simple APC which incorporates only a load-

ing/unloading device in pallets. Various types are available in small to large sizes. It is used as a transfer unit for the unmanned trailer.

Shuttle type. The dual type APC is shuttled in parallel to the X axis or У axis of the machiningАcentre. Pallets are changed at one place.

Turn type. This APC changes pallets by loading/unloading of pallets and turn operation. This type is believed to be convenient because workpiece can be set up at a predetermined place.

Rotary type is generally used as a loop APC or pallet magazine with four or more pallets. It is incorporated with a loading/unloading device at the

Square type is a sequential typeДwhich loads and unloads pallets at two places of X axis of the machining centre, i.e. loads from A and unloads from B. It performs loading/unloading and travel by combination of transfer bar and conveyor.

longitudinal centre portion, and can be connected with a maximum of two machining centres. It is often connected with a setup station for effective

workpiece setup. И

Index type. It is the turn type APC equipped with a predetermined angle indexing function and provided with a pallet stand in the periphery.

Separate type is connected with a pallet stand which is equipped with a loading/unloading device in the extended direction of both ends of the X axis of the MC table, a large-sized type being used for vertical boring machines. In this case, the shuttle type APC may sometimes be set on the extension side of the X axis.

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Turning type. This APC has been developed for vertical turning. An indexing type direction changer with a loading/unloading device is located at the centre of the APC. One of the right and left sides permits setup and power rotation type centering work, the other side being used as a standby station.

СConveyor type. Two methods are available. In one method, a pallet or a workpiece is carried on a conveyor, positioned in front of the machining centre, and loaded to or unloaded from the machining centre. In the other method, a pallet is positioned and fixed on a conveyor and machining operation is performed by the motions of X, Y and Z axes of the machining centre. Inиthe latter method, the conveyor type APC constructs a flexible transfer line (FTL).

Line type. In this method, the machining centre, pallet stand and pallet magazine are disposed on one side or both sides of a linear track on which an unmannedбtrailer runs. There are two types of unmanned trailers; a single type which transfers one pallet, and a twin type which transfers two pallets. The twin-pallet changer can form the basis of flexible machining cells in which several machining centres carry out identical or successive operations on families of parts.АThe twin type unmanned trailer greatly reduces pallet changing time. In a factory automation type equipment which connects many machining centers a 100-m or longer line type FMS can be constructed by loading an unmanned trailer with a controller and power source, using a trolley type power supply, Дand employing an optical data transport system for the transfer of data with the CNC of the machining centre.

VI. Give the definitions to the following abbreviations. You may need to refresh the information from the previous texts.

CNC _______________________________________________________И; FMS _______________________________________________________; APC _______________________________________________________; FTL ________________________________________________________; MC ________________________________________________________; AWC _______________________________________________________; DNC _______________________________________________________; NC _________________________________________________________; CAM _______________________________________________________; CAD _______________________________________________________; AGV _______________________________________________________; VLSI _______________________________________________________.

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VII. Work in pairs. Read the description of one APC type and let your partner guess it.

VIII. Choose the best continuation without looking back at the text. Discuss the results.

С1. Robot type is used as a/an…

a) … automatic workpiece changer. b) …shuttle.

c) … combination of transfer bar and conveyor.

b)и… minimum of two machining centres. c) … maximum of two machining centres.

2. Rotary type can be connected with a ...

a) … maximum of three machining centres.

3. In a conveyorбtype a workpiece is positioned … a) … in front of the machining centre.

4. There are two types of unmanned trailers: … a) … a single type and a twin type.

b) … between the machining centres. c) … behind the machiningАcentre.

b) … a simple type and a dual type.

c) … a sequential type and a combinatory type.

5. The APC is available in … types.

IX*. Imagine you are an editor of a technical journal. You are to edit the text for the issue. Read the Google translation and correct the inaccuracies. Compare your translations with your groupmates and choose the best editor!

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HOME TASK 12

A. Memorize the words from Ex. I and be ready to do a dictation.

B. Make a plan to the text “Workpiece transfer technology” and be

Сready to discuss this topic in your group.

C. Make a PowerPoint presentation (10 slides) about APC types. You need to find some more facts yourself in the Internet. Remember to discuss the assessment criteria (4 – 5) beforehand.

TEST YOURSELF

The APC is available in many types. These types are used depending

___ machining centres. It is often connected with a setup station for 21) workpiece setup.

Square type is a 22) ___ type which loads and unloads pallets at 23)

___ places of X axis of the machining centre, i.e. loads from A and unloads from B. It 24) ___ loading/unloading and travel by 25) of transfer bar and conveyor.

Separate type is connected with a pallet 26) ___ which is equipped with a loading/unloading device in the 27) ___ direction of both ends of the X axis of the MC table, a large-sized type being used for 28) ___ boring machines. In this case, the 29) ___ type APC may sometimes be set on the extension side of the X axis.

How many mistakes have you done? What are they?

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