RU2743389C1 - Detachable element automatic attachment unit - Google Patents

Abstract

FIELD: manufacturing technology.

SUBSTANCE: assembly comprises an active member comprising a geometrically locking member, a piston with a rod configured to reciprocate therein, and mating part having hole made with possibility of coupling with geometrical locking element. Unit is equipped with sensors to monitor position of active and mating parts and stock. At that, element of geometrical locking is made in form of bushing-collet, non-breaking part of which is rigidly fixed in active part coaxially with piston and with possibility of piston rod movement inside bushing-collet, and split part is made in form of truncated cone diverging outward. Mating part opening is made in the form of truncated cone diverging inside. Sensors are designed to control position of active and mating parts relative to each other and position of piston rod relative to active part.

EFFECT: higher specific load and stiffness of attachment with higher reliability and wider field of use.

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Description

The invention relates to robotics and can be used for automatic fastening of an actuator or workpiece to an actuator (for example, a robot arm).

Known is a mechanical device for replacing the end element, containing an active part equipped with a geometric locking element, inside which a piston with a rod is installed with the possibility of reciprocating movement, and a counterpart configured to mate with the piston rod and a geometric locking element (see patent TWI593525 , IPC B25J15 / 04, publication date 01.08.2017).

As the closest analogue, a device for the automatic change of a removable element is adopted, containing an active part equipped with a geometric locking element, inside which a piston with a rod is installed with the possibility of reciprocating movement, and a counterpart adapted to mate with the piston rod and a geometric locking element, for which it is provided with a hole (see patent US8005570, IPC G06F 19/00, publication date 08/23/2011).

The disadvantages of analogs are the relatively high specific load on the geometric locking elements made in the form of balls, which leads to a decrease in the total carrying capacity of the device, the dependence of the rigidity of the connection on the pressure in the pneumatic system and the need to determine the presence of a load using logical calculations based on the readings of inductive sensors.

The problem to be solved by the present invention is to develop a unit for automatic fastening of a removable element with increased reliability and rigidity of the connection.

The technical result, which is achieved when solving the problem, is expressed in an increase in the specific load and rigidity of the fastening while increasing the reliability and expanding the scope.

The problem is solved in that the unit for automatic fastening of the removable element, containing the active part, equipped with a geometric locking element, inside which a piston with a rod is installed with the possibility of reciprocating movement, and a counterpart made with the possibility of mating with the piston rod and the geometric locking element, for which it is equipped with a hole, it differs in that a collet sleeve is used as a geometric locking element, the continuous part of which is rigidly fixed in the active part, coaxial with the piston and with the ability to move the piston rod inside the collet sleeve, and the split part is made in the form of a truncated cone expanding outward, in addition, the mating part is made with the possibility of mating with the split part of the collet sleeve, for which the side surface of the hole is made in the form of a truncated cone expanding inward, in addition, the unit additionally contains sensors for monitoring the position of the parts and the rod.

In addition, the unit contains sensors for monitoring the position of the active and reciprocal parts relative to each other and the position of the piston rod relative to the active part.

Comparative analysis of the totality of essential features of the proposed technical solution and the totality of essential features of the prototype and analogues indicates its compliance with the "novelty" criterion.

In this case, the distinctive features of the claims solve the following functional problems.

The feature "a collet sleeve is used as a geometric locking element" allows increasing the contact area between the geometric locking element and the counterpart, since the mating between these parts does not occur as separate contact spots, but is distributed over the entire mating surface of the geometric locking element, as a result of which the specific load on the geometric locking element and additional loading of the device becomes possible.

The feature "the continuous part [of the collet sleeve] is rigidly fixed in the active part" excludes the movement of the collet sleeve relative to the active part.

The signs "[collet bushing is fixed] coaxially with the piston and with the possibility of moving the piston rod inside [it]" allow you to fix the position of the split part of the collet bushing in the hole of the counterpart by extending the piston rod and thereby complete the positive locking of the fastened parts even when the feed is turned off air.

Features “the split part [of the collet bushing] is made in the form of a truncated cone expanding outward, allowing to controllably change the rigidity of the collet bushing in the radial direction and to insert the collet bushing into a hole that is smaller than its radial dimensions.

Features "the counterpart is designed to mate with the split part of the collet bushing, for which the side surface of the hole is made in the form of a truncated cone expanding inward" provides the possibility of positive locking of the collet bushing in the hole provided the stem is extended.

The signs "the node additionally contains sensors for monitoring the position of the parts and the rod" and the signs of the dependent clause of the formula make it possible to determine the presence of a load (counterpart) and its approximation to the active part without logical processing of previous actions, while an abnormal loss or weakening of the load fastening is determined throughout the time of the closed state of the connection.

Figure 1 shows a longitudinal section of the unit for automatic fastening of the removable element in the open state.

Figure 2 shows a longitudinal section of the removable element assembly in a closed state.

Figure 3 shows a prototype unit for automatic fastening of a removable element:

a - in an open state with an active part installed on a floating platform;

b - in a closed state with an active part mounted on the robot flange.

The drawings show the active part 1, piston rod 2, counterpart 3 and its opening 4, continuous 5 and split 6 parts of the collet bush, sensors 7 for monitoring the position of active 1 and counterparts 3 relative to each other and the position of piston rod 2 relative to the active part 1.

In the active part 1, the continuous part 5 of the collet sleeve is rigidly fixed, coaxially with the inside of the collet sleeve.

The split part 6 of the collet bushing is made in the form of a truncated cone expanding outward.

The counterpart 3 is configured to mate with the split part 6 of the collet sleeve, for which the side surface of the hole 4 is made in the form of a truncated cone expanding inward.

The unit additionally contains sensors 7 for monitoring the position of the active 1 and mating 3 parts relative to each other and the position of the piston rod 2 relative to the active part 1.

The claimed device operates as follows.

In the open state (Fig. 1), the piston rod 2 is located inside the active part 1 and the petals of the split part 6 of the collet sleeve are in a free state.

When the active part 1 approaches the counterpart 3, under the control of the sensors 7, the petals of the split part 6 of the collet sleeve are pressed to the center and pass into the hole 4 of the counterpart 3.

After closing the active 1 and the counterpart 3, the piston rod 2 is extended (with the help of air), the petals of the split part 6 of the collet sleeve diverge in the radial direction and expand (and the reverse taper of the hole 4 creates a force component that closes both parts of the device) in the hole 4 of the counterpart part 3.

Thus, in the closed state (Fig. 2), the parts of the assembly are fixed relative to each other by means of the piston rod 2, which remains due to frictional forces in the position that fixes the collet sleeve, even with a loss of compressed air pressure, thereby preventing the petals of the split part 6 collet bushings shrink and come out of hole 4 of counterpart 3.

To disconnect the counterpart 3 from the active part 1, the procedure is carried out in the reverse order.

Both the active and the reciprocal part can act as a removable element.

The use of a geometric locking element with a developed surface allows the use of different materials (plastic, composite, metals), which allows changing the production technology and price in a wide range (for example, injection molding of a plastic collet is a mass production technology, and the manufacture of a steel tool collet is special or precision).

The authors have created a prototype with the following characteristics

1. Materials:

active part - aluminum alloy D16;

counterpart and piston - steel 40X13;

collet bushing - caprolon PA6 grade A.

2. Dimensions:

overall dimensions of the sample: diameter 100 mm, length 98 mm;

overall dimensions of the collet bush: diameter 40 mm, length 41 mm, inner diameter (for the piston rod) 20 mm;

diameters of the split part of the collet bush: minimum 30 mm (in a compressed state when the petals are closed), maximum 32.8 mm (in a free state), deformation by a radius of 1.4 mm.

Tests were carried out - the prototype was loaded along the axis with a weight of at least 31 kg for 5 minutes a statistically significant number of times before and after the life tests, while the connection was not unlocked, which was confirmed by information from the inductive closure sensor and the measurement data of the gap between the parts of the specimen being closed.

Claims (2)

1. A unit for automatic fastening of a removable element, comprising an active part including a geometric locking element, inside which a piston with a rod is installed with the possibility of reciprocating movement, and a counterpart having an opening adapted to mate with a geometric locking element, characterized in that it equipped with sensors for monitoring the position of the active and counterparts and the rod, while the geometric locking element is made in the form of a collet sleeve, the continuous part of which is rigidly fixed in the active part coaxially with the piston and with the ability to move the piston rod inside the collet sleeve, and the split part is made in the form of a truncated cone expanding outward, while the opening of the counterpart is made in the form of a truncated cone expanding inward. 2. The assembly according to claim 1, characterized in that said sensors are designed to monitor the position of the active and mating parts relative to each other and the position of the piston rod relative to the active part.

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