LT5269B - Clamping apparatus with a chuck and a work piece carrier fixing thereto - Google Patents

Abstract

In a clamping apparatus for fixing a work piece carrier with a clamping pin in a clamping chuck, the chuck is provided with a central opening for receiving the clamping pin and with clamping mechanism firmly keeping the clamping pin in the central opening. The central opening has a conical insertion section, and the clamping pin comprises a rear section with exposed aligning surface portions, engaging the conical insertion section to align the clamping pin with regard to the chuck in X- and/or Y-directions. Circular bearing surfaces of seat portions on top of the clamping chuck constitute the Z- stop for the work piece carrier. For pneumatically cleaning the exposed aligning surface portions, the conical insertion section is provided withgas outlet openings, located corresponding to thearrangement of the exposed aligning surface portions. The surface areas of the work piece carrier that will rest on the bearing surfaces of seat portions are pneumatically cleaned by gas outlet openings located in th

Description

In the locking device, the clamping device for fixing the part holder with the locking pin in the gripper is provided with a central opening for receiving the locking pin and a locking mechanism for holding the locking pin firmly in the central opening. The central opening has a conical insertion channel and the locking pin has a rear portion with open centering surface sections that allow the locking pin in the conical insertion channel to be locked in the X and / or Y directions. The circular support surfaces at the top of the support section clamp provide Z braking for the part holder. For pneumatic cleaning of open centering surface sections, the conical insertion channel is provided with gas outlets spaced to accommodate correspondingly open centering surface sections. The surface areas of the part holder that rest on the support surfaces of the support sections are pneumatically cleaned through the gas outlets located at the center of the support surface of the support sections.

BACKGROUND OF THE INVENTION The invention relates to locking devices with a clamp and a part holder having a locking pin. More particularly, the device of the present invention consists of a locking jaw and a part holder adapted to be releasably connected to the jaw, the part holder having a flat lower surface and a locking pin protruding from the flat lower surface.

The clamping clip is provided with a central opening for receiving the clamping pin of the component holder, the central opening having a tapered insert portion and having a locking mechanism for clamping the clamping clip of the component holder in the central opening of the clamp.

Such a locking device is generally used for securing workpiece holders with one or more pieces mounted in the machining area of the machine in a well-defined and predetermined position. Typically, the machine gripper is secured within the machining area of the machine and the part holder with the provided locking pin is releasably connected to the gripper.

In order to capture details of different dimensions, so-called palletizing systems are known which have a plurality of grippers, usually two, four, six or eight. These numerous clamps, which are fitted with component holders, can fix two, four, six or eight locking pins, depending on their size. In some cases, the part holder may be equipped with an odd number of locking pins. Because individual grippers generally have neither means for preventing the locking pin from rotating nor means for adjusting the locking pin in relation to the Z axis, it may be useful to provide one or more grippers with positioning means for positioning without X- and Y-positions as well as angular positions. with respect to. As it exits, the fixture holders with multiple locking pins can be secured to the gripper, if necessary, for precise linear and angular positioning. It is understood that in this case the part holder must be provided with positioning means capable of interacting with the aforementioned gripper positioning means.

The accuracy of the relative position between the workpiece holder and the gripper can be severely impaired, especially by contaminating the machine's elements responsible for precision positioning.

Accordingly, with conical centering and positioning surfaces, there is a particular risk of dirt particles adhering to or settling on the conical insertion portion of the locking pin and / or the conical alignment surface.

Document DE 4110857 discloses a device for connecting a tool holder to a machine-tooled shaft. The PTO shaft is made with an opening for inserting the shaft part of the tool holder. The opening has upper and lower conical portions with an annular recess having a support surface disposed between the two conical portions. The shaft portion of the tool holder is fitted with two tapered rings supported by elastic supports. Between the two conical rings is located a locking mechanism having two radially movable locking parts. At the top, these locking portions are provided with wedge-shaped surface areas which, in their fixed position, lie on the bearing surface of the annular recess. By providing elastic supports, the tapered rings may move axially relative to the shaft portion of the tool holder and the shaft portion may be pushed into the opening after the tapered rings rest on the tapered portion of the hole. The tapered rings themselves are made with grooves. The shaft portion has a flange portion having a flat annular surface at its lower end serving as a Z-direction stop member.

leaning against the front face of the PTO shaft to lock the shaft portion. Both the common locking pins (Fig. 5) and the section locking pins (Fig. 1 and Fig. 3) can be secured in the opening of the PTO shaft. Thus, the main idea of the present invention is that the part holders with different locking pins can be secured by the machine shaft. It will be appreciated that such a locking device is not at all suitable for attaching the part holder to the machine shaft PTO in a very precise and reproducible manner.

U.S. Patent 5,961,261 discloses a locking system with a locking cylinder for retraction and a retaining retaining nipple. The locking cylinder is made with a central bore for inserting the retaining nipple. The nipple itself is provided with centering surfaces to ensure proper positioning inside the center bore of the cylinder.

In addition, at least one cutter is provided in the form of a cutting surface or a cutting edge. If any piece is adhered to the centering surface of the nipple or cylinder, these pieces will be cut and removed. The cutting tools on the nipple may be radially extended and have several independent cutting edges, or may be extended by a circle. The locking cylinder is provided with a plurality of uniformly distributed gas outlet openings leading to free gaps between the cutting edges. When providing for these clearances, the area in front of the outlet openings 14, 15 must be kept free of contamination particles, thereby avoiding contamination of the outlet openings. However, in the area of centering surfaces, no venting holes are provided.

U.S. Patent 5,415,384 describes a device for securing a workpiece to a workbench in a well-defined position. The unit has a base and a part holder adapted to be placed on and fixed to the base. The base is made with four centering rulers, each fitted with a groove in the flat element and elastically flexible in the Z axis to align the part holder in the X and Y directions. Separate locking pins are provided for fixing the part holder to the base, but do not perform any centering or leveling function.

Finally, the German patent DE 200 21 407 discloses a locking device for fixing a screw on a machine tool table. This locking device has a baseplate with a built-in piston, which is covered with a baseplate and fastened to the baseplate. The top surface of the cover plate has sockets serving as Z stop members. The base plate is made with air ducts that open in the center into socket parts and are adapted for cleaning surfaces.

It is an object of the present invention to provide an improved locking device having a gripper and a workpiece holder adapted to releasably engage a gripper having surface areas that ensure relative positioning between the workpiece holder and the gripper is easily maintained without contamination.

For this and other purposes, the present invention provides a locking device having a locking device and a part holder adapted for releasably engaging with the gripper.

The part holder has a flat top surface and has a locking pin protruding from the flat top surface.

The locking jaw is made with a central opening for receiving the locking pin of the part holder with a conical insertion channel and has a locking mechanism for rigidly locking the locking pin of the part holder in the central opening. The locking pin has a rear portion adjacent to the flat upper surface of the component holder having a plurality of exposed surface sections adapted to align the conical insertion portion of the central opening in the X and / or Y directions.

In addition, the gripper is provided with gas outlet openings, which are located in the central openings of the conical insertion channel for blowing the gas medium on the exposed surface sections, thereby cleaning their surfaces by inserting a locking pin into the central opening of the gripper.

Thus, one of the basic ideas of the present invention is to ensure accurate positioning of the locking pin, not by means of large positioning surfaces, but by providing a locking pin with a series of small open flattening surface sections with only limited expansion by means of precisely locking pin X and / or In the Y directions, the center hole of the gripper in the tapered insertion channel. These small open sections of the smoothing surface can easily be maintained clean by blowing air or other gaseous media through openings made by the appropriate arrangement of the tapered insertion passage. Due to the fact that these equalization sections are also open and small in size, blowing compressed air ensures complete and highly efficient cleaning.

Examples of embodiments of this device according to the invention will be further described with reference to the accompanying drawings, in which:

FIG. Figure 1 is a perspective view of the clamping jaw with the component holder;

FIG. Figure 2 is a longitudinal sectional view and a side view of the component holder; and

FIG. Figure 3 shows a general view of a machine tool table and workpiece holder made with four locking pins.

FIG. 1 is a schematic view of a locking device according to a first embodiment of the present invention. The locking device has a gripper 1 as well as a part holder 2 provided with a locking pin 3 suitable for securing the part holder 2 to the gripper 1. In this example, the part holder comprises the part itself.

The gripper 1, which is connected to the machine table by means of clamps (not shown), is provided with a central opening 4 adapted to insert and secure the locking pin 3 in the gripper 1. The upper part of the central opening 4 is tapered to form a tapered insertion channel 5. the surface is provided with a plurality of support surfaces 6 on which the flat bottom surface 7 of the component holder 2 is to be held when the component holder 2 is finally locked in the gripper 1. Thus, a plurality of parts of the support surfaces 6

The circular support surface sections 6 form a first inner group and a second outer group. The inner group consists of four support surface sections 6a arranged on the circumference of a first, smaller radius circle coaxial with the central longitudinal axis of the central opening 4. The outer group has twelve surface support sections 6b arranged on the circumference of a second, larger radius circle coaxial with the central longitudinal axis of the central opening 4. In the center of each of the surface support sections 6a and 6b are provided corresponding openings 8a and 8b through which air can be blown.

The conical insertion channel 5 of the gripper 1 has four openings 9 through which air can be blown. However, in Fig.1 only two openings (holes) of four are visible. Further, the gripper 1 is provided with a locking mechanism (not shown in Fig. 1) for inserting the locking pin 3 and securing it in the gripper. The outer side of the gripper 1 is provided with two connectors 10 and 11, one suitable for connection to a compressed air source for supplying air to the openings 8a, 8b and 9, the other adapted to be connected to a pressed environment for actuating the gripper locking mechanism. set forth below.

The locking pin 3 connected to the part holder 2 has a rear part adjacent to the lower surface 7 of the part holder having four open centering surface sections 12, 12a. These open centering surface sections 12, 12a are operable to interact with the conical insertion channel 5 of the central opening 4 of the gripper 1 to align the part holder 2 with respect to the gripper in the X and Y directions as soon as the locking pin 3 is inserted into the central opening. 12, 12a extends through a small fragment of the rear section of the above locking pin 3 and protrudes above the surface of this rear section. The sum of the surface areas of the four open centering surface sections thus equates to only a fraction of the total surface area of the central opening tapered insertion channel 5, which determines the high surface load on the open centering surface sections 12, 12a by securing the part holder 2

5 ways to reduce their exposure to contamination.

The four open centering surface sections 12, 12a are uniformly distributed around the periphery of the rear section of the locking pin 3 where only two of them are shown in Fig. 1, i.e.. y. the front section 12 and one of the side sections 12a. The position of the air outlets 9 in the conical insertion channel 5 of the central opening 4 of the gripper 1 corresponds to the arrangement of the four open centering surface sections 12, 12a of the locking pin 3 so that each of the open centering surface sections 12, 12a faces one of the air outlets 9. The pin 3 to the central opening 4 of the gripper 4. Thus, by blowing air through the openings 9 during insertion and locking operations, the open centering surface sections 12, 12a are pneumatically cleaned. It is understood that in this case of only one part holder 2 and one locking jaw 1, means must be provided for adjusting the angular position of the part holder 2 relative to the Z axis by inserting the locking pin 3 into the central opening 4 to ensure that the open centering surface sections 12, 12a are opposite apertures 9. As suitable means are known in the art and readily available to any person skilled in the art, such means are not shown in the drawings and are not further explained.

Fig. 2 is a longitudinal sectional view of the gripper 1 and a side view of the component holder. The gripper 1 has an upper part la and a lower part lb. The lower part lb may be part of the machine table. The locking mechanism for securing the part holder 2 to the clamping pins 3 of the gripper 1 has a piston 15 which slides under the action of the springs 20 and a plurality of locking balls 16. The locking balls 16 enter the radially extending holes 17 orifice 4. In order to move the piston 15 against the force of the springs 20 to its upper end position, a pressure chamber 19 is provided between the lower part lb of the gripper 1 and the piston 15. The pressure in the chamber 19 may be pneumatic or hydraulic.

The locking pin 3 connected to the part holder 2 has a head portion 13 disposed at its front end (i.e., at its lower end as seen in Fig. 2). The head portion 13 has a cut cone shape and forms a peripheral shoulder 14 disposed at its rear end (i.e., the upper end as seen in Figure 2). When the locking pin 3 is inserted into the central opening 4 of the gripper 1, the locking balls 16 are radially pressed against this shoulder 14 to insert and lock the locking pin 3. The head part 13 of the locking pin 3 is provided for centering the locking pin 3 in the central opening. the centering surface sections 12, 12a at the rear of the locking pin ensure precise positioning, with substantially complete insertion of the locking pin 3 into the central opening 4, the exposed centering surface portions 12, 12a lie on the conical insertion channel 5 of the central opening, accurately positioning the locking pin 3 with respect to the central opening 4 in both X and Y directions. In order to allow the locking pin 3 to be inserted into the central opening 4 of the gripper 1, the piston 15 must be pushed against the force of the springs 20 into its upper end position; in this way, the locking balls 16 can move radially outwardly into the groove provided in the piston 15.

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LT $ 269 B

When the locking pin 3 is inserted into the central opening 4 of the gripper 1, the part holder is freely lying on the gripper 1. In order to lock the part holder 2 in the gripper 1, the pressure in the pressure chamber 19 is reduced by determining the downward movement of the piston 15. Then, in a known manner, the locking balls 16 are pushed radially inwardly against the shoulder 14 of the locking pin 3, and thus push the latter downwards, i.e. y. Towards the clamp 1. Due to the high axial pulling force, up to 20 KN acting on the locking pin, both the locking pin 3 is partially stretched, resulting in a reduction of its outer diameter and an increase in the tapered insertion channel 5 of the central opening. In this way, the locking pin 3 is pushed further into the central opening 4 until the flat lower surface 7 of the part 2 rests on the chuck support sections 6a, 6b to form a Z-brake. The result is that the part holder 2 is locked in relation to the gripper 1 not only in the X- and Y-directions but also in the Z-direction as well.

The dimensions of the locking pin 3 are chosen such that between the support sections 6a, 6b of the gripper 1 serving as Z-reference and the flat lower surface 7 of the part holder 2 after accurate centering but before locking the part holder 2 in the gripper 1, t, y the part holder 2 lies only with its characteristic mass on the gripper 1, with a gap of 0.01 - 0.02 mm. The elements of the locking device necessary for its operation are aligned with one another in terms of dimensions and shape such that, after precise positioning in the X- and Y20 directions of the locking pin 3 and, in addition, the part holder 2 in the direction of the part the flat lower surface 7 of the bracket 2 and the zeroing of the support sections 6a, 8a of the gripper 1 are achieved mainly by the elasticity of the material of the pin 3, as in the region of the central opening 4 of the gripper 1. Thus, in contrast to the locking devices described, neither parts nor elements that are elastically elastic in the Z direction are required.

The upper part of the gripper 1 has passageways 21, 22 through which compressed air can be introduced into openings 8a provided in the support sections 6a as well as openings 9 provided in the region of the conical insertion passage 5. In order to supply compressed air to the openings 8b of the outer support surface sections 6b, the bottom la of the upper part of the gripper 1 is formed with an annular channel 24. The annular channel 24 connects to the opening 23. The opening 23 and the channels 21, 22 are interconnected by channels. not shown.

During the locking operation of the component holder 2, air is blown through all openings 8a.

8b and 9. This air cleans both the surface sections 10a, 6b of the bottom surface 10a of the part holder 2, which will rest on sections 6a, 6b of the retaining surface 1 of the gripper 1, and 12, 12a. As the gap between the openings 8a, 8b and the bottom 7 of the part holder 2 and between the centering surface sections 12, 12a of the locking pin 3 and the conical insertion channel 5 of the clamp 1 decreases, the surface portions adjacent to the openings 9 are also pneumatically cleaned. Due to the limited surface area of both the centering surface sections 12a, 6b of the stop bracket sections 6a, 6b and the locking pin 3, complete cleaning of the associated supporting surfaces is ensured.

Seen from the side with respect to the gripper 1, there is provided a spacer 25 which protrudes a certain size 10 above the top of the gripper 1; the function and mode of operation of this spacer 25 will be further elaborated further in connection with FIG.

Fig. 3 shows a perspective view of a machine tool table 26 made with four grippers and a component holder 27 provided with four locking pins 3, 3a, 3b, 3c. In addition to these four locking pins 3, 3a, 3b, 3c, the left locking pin 3, the front locking pin 3a, as well as the rear locking pin 3b are shown separately in perspective view, near the part holder 27. Thus, the left locking pin 3 determines the starting position by providing four open sections 12, 12a of the centering surface, positioning in both the X and Y directions. However, only the front surface section 12 and the side surface section 12a are visible

FIG. 3. The front locking pin 3a is provided with two open centering surface sections 12b and serves to position the workpiece holder 27 along one of the two perpendicular axes, i. y. X direction. The rear locking pin 3b is also made with two open centering surface sections 12c and is used to position the part holder 27 along one of the two perpendicular axes, i.

y. Y direction. However, the right locking pin 3c has no open centering surface sections and is only used to lock the part holder 27 in the Z-direction. In addition, the outer peripheral spacer 25 shown in Figs. 3, sealingly contacts the underside of the component holder 27, thereby protecting the machine table with four locking pins from contamination. By pumping air through openings 8a, 8b, 9, it is possible to lock the workpiece holder 2, 27 finally on the machine table 26, if necessary.

For setting the starting position, the locking pin may be provided with three open centering surface sections that are offset from each other at 120 °, instead of four open centering surface sections 12, 12a, which are offset from each other at 90 °. Similarly, a locking pin having more than four open sections of the centering surface may be provided for initial positioning. However, the advantage of the structure shown in Fig. 3 and that described above can be seen in that the tapered insertion channel 5 having four air outlet openings 9 and both a locking pin having two open centering surface sections and a locking pin with four openings sections of the centering surface may be rounded.

Claims (8)

DEFINITION OF INVENTION 1. A locking device with a gripper (1) and a locking pin (3) which can be locked therein, with the gripper (1) provided for holding the locking pin (3) with the central opening (4) and the locking mechanism of the locking pin (1). ), the central opening (4) having a tapering taper insertion channel (5), characterized in that the locking pin (3) is provided with a plurality of 10 for positioning the locking pin (3) of the centering surface sections (12, 12a) in the X and / or Y directions in the tapered taper insertion passage (5) of the gripper (1) and in that the recesses (9) are provided in the insertion passage (5) ) for venting gas corresponding to the centering surface sections (12, 12a) of the locking pin (3) and for the centering surface sections (12,12a) of the locking pin (3) 15 clean up. 2. A locking device according to claim 1, characterized in that the locking pin (3) is provided with n centering surface sections (12, 12a) for positioning in X and Y directions relative to each other. In the case of 20, 360% at an angle of 7, where n is an integer, preferably 1, 2, 3 or 4. 3. The locking device of claim 2, wherein said centering surface sections (12,12a) are in the form of an open section in a conical shape. Locking device according to any one of the preceding claims, characterized in that the locking pin (3) is provided with an anterior fragment (13) for being an approximate centering means, and in that the centering surface of the locking pin (3) is exposed. sections (12,12a) for be 30 precise centering. 5. A locking device as claimed in any one of the preceding claims. the jaw (1) is provided with a number of support surfaces (6) acting as ¹¹ LT 5269 B braking Z direction, which are provided with openings (8a, 8b) of fumes piece carrier (2) supporting surface (7) cleansings, said support with the surface (s) (7) resting on the support surfaces (6) and the support surfaces (6) being round. A method of locking a part holder on a machine table with a locking device as claimed in any one of claims 1 to 5, comprising the steps of inserting the locking pin (3) in a central opening (4) further defining it in X and Y directions. for blowing gas during the locking operation 10 (e.g., air) through openings (8a, 8b, 9) for securing the open centering surface sections (12, 12a) of the locking pin (3) and the parts for contacting the bearing surfaces (7) of the holder with the bearing surfaces (6) of the gripper (1). , which serve as Z-stop and, after precise positioning, continue to push the locking pin (3) in the Z direction, with the locking mechanism moving the locking pin (3) deeper into the center 15 opening (4) utilizing the elasticity of the material of the locking pin (3) and / or the gripper (l) with the possibility of finally fixing the part holder (2, 27) on the machine table (26) by suctioning air through the openings (8a, 8b, 9). 7. A device in which the machine table is provided with at least two locking devices 20. A device according to claims 1-5, characterized in that the machine table (26) is provided with at least two grippers and the component holder (27) is provided with a plurality of locking pins (3, 3a, 3b, 3c), one of the locking pins (3). 3) with the position locking of the part holder (27) in the X and Y directions and at least one additional locking pin (3a, 3b) at the default position 25 pieces for fixing the angular position of the holder (27) about the zero point of the Z axis. 8. A device according to claim 7, wherein at least one additional locking pin (3a, 3b) is provided for orientation only in the X and Y directions due to the fact that the rear section of the locking pins (3a, 3b) is 30 provided with at least two opposing surface portions (12a, 12b).