CZ309970B6 - Pneumatic vice for CNC machining centres - Google Patents

Abstract

The pneumatic vice for CNC machining centres consists of a body (1) attachable to the machining centre table and provided with a pair of sliding jaws (6) located on the motion screw (4). In the body (1) of the vice there is a pneumatic rotary motor (2) linked via a gearbox (3) with the motion screw (4). The sliding jaws (6) are provided with pressurized oil, expandable inserts (7) to create a friction joint with exchangeable jaws (5). The expandable inserts (7) are interconnected with a piston (8) and disc springs incorporated in the sliding jaws (6). The motion screw (4) is preferably provided with a left and right thread for moving the left and right sliding jaw (6) against each other. The body (1) of the vice is fitted in the preferable design with telescopic covers (12) against the ingress of coarse impurities. The pneumatic vice is provided with clamps and/or clamping pins (13) for the clamping on the machining centre table.

Description

Pneumatic vice for CNC machining centers

Field of technology

The invention relates to a pneumatic vice for CNC machining centers comprising a body connectable to the machining center table, equipped with a pair of sliding jaws located on a movement screw with left and right threads. The solution concerns clamping automation for CNC machine tools.

Current state of the art

Currently, there is a wide range of different versions and sizes of manual vices for machine tools. For roughing operations, a robust vise is required to ensure a rigid and secure clamping of the blank or workpiece. For precise clamping during the production of precision parts, a very precise processing and design of these vices is required. As a result of the limited number of technically skilled workers, automation devices for serial and piece production are currently beginning to gain ground. Piece production has its specifics, especially in terms of the flexibility of adjusting to a different type of production.

There are hydraulic-pneumatic blocks on the market that can be used for these tasks. However, they have limitations when converting to another type of product, and above all, the range of clamping force on a very limited stroke.

These are mostly relatively simple structures suitable for automation, but only for a specific manufactured part. The jaws must be changed manually by the machine operator. The movement of the jaws is usually small. The pneumatic version usually has insufficient clamping force for heavier machining.

There are also classic manual vices, but these are not suitable for the given purposes.

The essence of the invention

The above-mentioned shortcomings are largely eliminated by a pneumatic vice for CNC machining centers comprising a body connectable to the table of the machining center, equipped with a pair of sliding jaws located on a moving screw, according to the present invention. Its essence is that the body houses a pneumatic rotary motor connected via a gearbox with a moving screw, and the sliding jaws are provided with oil pressure by expandable inserts to create a frictional connection with the exchangeable jaws, while the expandable inserts are connected to the piston and are further provided with disc springs integrated in sliding jaws.

The movement screw can be with left and right threads to move the sliding jaws against each other, or with only one thread to move only one jaw, the other being stationary.

The body of the vise is preferably interwoven with channels for cleaning the contact surfaces between the sliding jaws and the exchangeable jaws and can be equipped with telescopic covers against the ingress of coarse dirt.

In a preferred embodiment, the pneumatic vise is fitted with end position sensors for information on the position of the clamping sliding jaws and indirect measurement to obtain the opening position of the sliding jaws, which are connected to the superior computing device of the machining center.

The pneumatic vise is equipped with clamps and/or clamping pins for clamping on the machining center table.

- 1 CZ 309970 B6

At first glance, the vice does not differ much from the classic manual one. In the submitted solution, it was possible to compactly build a pneumatic rotary motor in the body of the vise, which rotates the movement screw through the gearbox and usually moves it through the left and right threads with the left and right sliding jaws. It is therefore a self-centering vise. Hardened inserts are placed on these sliding jaws, which are expanded by oil pressure, thus creating a frictional connection between the surface of the insert and the inserted replacement jaw. The required pressure is generated by the piston acting on the oil and is further given by disc springs integrated in the sliding jaws. This allows you to clamp and unclamp the exchangeable jaws, which can be adapted to a specific semi-finished product or the shape of the workpiece. The depressurization of the inserts for replacing the replaceable jaws takes place at the bottom dead center of the sliding jaws, when the clamping force is converted to the deformation of the disc springs, and when the oil pressure drops, the replaceable jaws can be easily replaced. For full automation, an industrial robot can be used, which can replace the exchangeable jaws with others and store the unnecessary ones in a magazine for further use.

The body of the vise is interwoven with several channels for cleaning the contact surfaces during automated replacement. This is a necessary condition for the reliability and accuracy of the entire production cell. That is why the body is equipped with telescopic covers against the ingress of coarse dirt. For information about the position of the clamping sliding jaws, the vise is equipped with end position sensors and indirect measurement to obtain the position, i.e. the opening of the sliding jaws, which communicate with the superior computing devices of the production cell or CNC machine. The movement screw is housed in a central housing with rolling elements, where it is sufficiently covered to prevent the ingress of dirt. In the event of a compressed air failure, it is possible to loosen and tighten the vise manually using a hex key.

The vice according to this invention does not lose anything in terms of ease of use and can also be used to automate production processes.

The vise is designed to be unmanned by humans. It was created for this reason, because there is pressure for fully automated production cells. It is dimensioned to min. 200 thousand production cycles. If necessary, it can also be used for manual operation by a person who controls it with a classic pneumatic valve. The advantage is also the use of compressed air, which is available in any manufacturing company and is ecological compared to, for example, hydraulic oil.

Clarification of drawings

The pneumatic vise for CNC machining centers according to this technical solution will be described in more detail using specific examples of execution with the help of the attached drawing, where Fig. 1 shows an exemplary vise in an exploded view in an axonometric view.

An example of the implementation of the invention

An exemplary pneumatic vice for CNC machining centers includes a body 1 connectable to the table of the machining center, equipped with a pair of sliding jaws 6 located on the movement screw 4 with left and right threads located in the central housing 10 of the body 1. The body 1 also houses a pneumatic rotary motor 2 connected through the gearbox 3 with the movement screw 4. The sliding jaws 6 are provided with oil pressure by expandable inserts 7 to create a frictional connection with the exchangeable jaws 5. The expandable inserts 7 are connected to the piston 8 and are equipped with disc springs integrated in the sliding jaws 6. The body 1 of the vise is interlaced channels for cleaning the contact surfaces between the sliding jaws 6 and the exchangeable jaws 5. The body 1 is also equipped with telescopic covers 12 against the ingress of coarse dirt. The pneumatic vise is equipped with end position sensors 11 for information on the position of the clamping sliding jaws 6 and indirect measurement 14 for obtaining the opening position of the sliding jaws 6, which are connected to the superior computing device of the machining center. The pneumatic vise is equipped with clamps and/or clamping pins 13 for clamping on the machining center table.

- 2 CZ 309970 B6

In use, the pneumatic vise is clamped on the table of the CNC milling machine with clamps or clamping pins 13. The source of compressed air is supplied either through nozzles in the machine table or by an external connection using flexible coiled hoses, which is controlled by a superior computing device or robot control system. The service robot has a reservoir of semi-finished products, i.e. workpieces, which it places in a vice and starts the production cycle of the CNC machine. In the case of adjustment to a different type of production, it will use the magazine of exchangeable jaws 5, which are already adjusted to a specific semi-finished workpiece. The production cell can be expanded with a magazine of gripping heads due to the dimensional and shape differences of the semi-finished products - workpieces. The setting of the clamping force can be controlled using the throttle valve 9 and the position of the sliding jaws 6 can be measured through the indirect measurement 14 to set a specific clamping dimension. As already mentioned, the main advantage is the possibility of using the full range of clamping force in the entire working stroke of the vise. In this way, a fully automatic production cell with a CNC machine for piece and serial production with automatic adjustment to a different type of production can be obtained. Of course, within the size and weight limits of all participating machines and their peripherals.

The solution is suitable for vices with a width of approx. 125 mm and can develop a clamping force in the range of 10 d 35 KN over the entire length of the stroke. In combination with the automated exchange of exchangeable jaws 5 using an industrial robot, a solution can be obtained for flexibly automatable clamping of various workpieces and semi-finished products. All power operated pneumatically with normal workshop compressed air distribution.

Exemplary dimensions of the pneumatic vice are: width 12 mm, length 330 mm, height 130 mm and weight approx. 30 kg. The pneumatic vise has a clamping force over the entire length of the stroke, i.e. from 0 to approximately 150 mm.

The pneumatic vice can be used in a production cell that contains a superior control system for managing the flow of orders and work queues, a manipulator or an industrial robot, a CNC machine tool with a large tool magazine, a magazine for blanks or exchangeable pallets, a magazine for exchangeable vice jaws and a magazine for technological and of gripping heads for a manipulator or an industrial robot.

A production cell controlled by a superior control system or PLC is an automated workplace for the possibility of flexible conversion to another type of product. The main element is a CNC machine tool, which performs the main production operation. The remaining peripherals are used for the possibility of fully automatic production changes at the workpiece level - a magazine for semi-finished products or interchangeable pallets, a tool, a large-capacity magazine for CNC machine tools, a clamp - an automatic vice with automated exchange of clamping jaws using a manipulator, an NC program - an internal memory of production programs in the superior control system and their calls according to the work queue. Everything must be logically aligned and controlled. Effective removal of chips and dirt from the machine tool area must be ensured. The shape limit will depend primarily on the method of clamping and the shape of the vice's replaceable jaws stored in the magazine. A necessary condition for reliable operation is detailed preparation and simulation of the entire production cycle at the level of the electronic twin.

Essentially, the only condition for reliable operation is the need to lubricate the compressed air and clean the functional surfaces at certain intervals. It is a very universal solution that can be used for a flexible automated production cell.

Industrial applicability

The pneumatic vice for CNC machine tools will find application as part of automated production cells with CNC machine tools with the possibility of automated conversion to another type of production without operator intervention.

Claims (6)

PATENT CLAIMS 1. A pneumatic vise for CNC machining centers containing a body (1) connectable to the table of the machining center, equipped with a pair of sliding jaws (6) located on a moving screw (4), characterized in that a pneumatic rotary motor is located in the body (1) of the vise (2) connected through the gearbox (3) with the movement screw (4) and the sliding jaws (6) are equipped with expandable inserts (7) for putting on the exchangeable jaws (5) and fixing them by means of a friction joint, while for expanding the expandable inserts (7) these are connected to the piston (8) by oil pressure. 2. A pneumatic vise according to claim 1, characterized in that the movement screw (4) is provided with left and right threads for sliding with left and right sliding jaws (6) opposite each other. 3. A pneumatic vise according to claim 1 or 2, characterized in that the body (1) of the vise is interwoven with channels for cleaning the contact surfaces between the sliding jaws (6) and the exchangeable jaws (5). 4. A pneumatic vise according to any one of claims 1 to 3, characterized in that the body (1) of the vise is fitted with telescopic covers (12) against the ingress of coarse dirt. 5. A pneumatic vise according to any one of claims 1 to 4, characterized in that it is fitted with end position sensors (11) for information on the position of the sliding jaws (6) and indirect measurement (14) for obtaining the opening position of the sliding jaws (6), which are connected to the superior computing equipment of the machining center. 6. A pneumatic vice according to any one of claims 1 to 5, characterized in that it is provided with clamps and/or clamping pins (13) for clamping on the machining center table.