RU2397857C2 - Gripping module - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention refers to machine building and can be implemented at gripping and placing parts on working surface facilitating long travel run of gripper head. The gripping module consists of a case, of the gripper head in form of a deformed suction cap, of a return spring and of a pneumatic drive of one-side action, a working chamber of which is connected to a pneumatic line of excess air pressure via a valve. The gripping module is equipped with a cover spring loaded to the case with the return spring thereby forming the working chamber of the pneumatic drive. The suction cap is equipped with a lever for gripped part positioning and is fixed on the cover installed on the case wherefrom it can be detached and transferred to the direction of the gripped part due to inertia forces and to the case - due to the return spring. On the case there is mounted a permanent magnet facilitating force interaction with the cover.

EFFECT: increased operation speed and reliability of device at considerable increase of range of gripper head travel.

3 cl, 3 dwg

Description

The proposed device relates to the field of mechanical engineering, robotics and can be used when taking and installing parts on a work surface with the required travel of the gripping head.

Known gripping modules that provide the capture and installation of parts that contain a gripping head with a drive for its vertical movement (see AS No. 1389154 "Gripping head", Sysoev SN, Cherkasov Yu.V. Aggregate-modular gripping device of the robot // Mechanization and automation of production. - 1987. - No. 1. - C.3). The application of the traditional operation scheme of the drive for vertical movement of the gripper, the control system leads to low reliability and low speed associated with a long time to install the part. The implementation of control systems for the drive of vertical movement on a hardware principle (see A.S. No. 1540177 "Vacuum gripping device", Sysoev S.N., Cherkasov Yu.V.) slightly improves performance.

Known capture modules created using the mechatronic construction principle (see Russian patent No. 2073601 "Vacuum gripping device", Sysoev S.N., Cherkasov Yu.V., Mokeeva E.V., Glushkov A.A.), where for The supply is applied overpressure. The vacuum gripping device comprises a vertical suction cup drive made in the form of two single-acting pneumatic cylinders kinematically connected to each other. Moreover, one pneumatic cylinder is designed to perform the function of the “take” part of the device, and the second to “install” the part. These functions are sequential execution of the operations “lowering the grip on the surface of the part”, “grabbing or releasing the part”, “raising the suction cup”.

This device, having increased high speed, has a complex structure, since the drive for vertical movement of the suction cup consists of two pneumatic cylinders, and the suction cup is made with a peripheral cavity, which affects the overall dimensions of the device.

Gripping modules are known (see RF patent No. 2318653 "Gripping head", Sysoev S.N., Bakutov A.V., Orekhov N.S., published in Bull. No. 7, 03/10/08). In the device, the drive for vertical movement of the gripper is made in the form of a double-acting power cylinder, the piston cavity of which is connected to the rod cavity, and an inductor is additionally installed in the pneumatic line for connecting the distributor and the safety valve. This device limits the vertical movement of the capture of the overall dimensions of the drive. The use of pipelines, a unified safety valve with limited flow characteristics reduces the reliability and speed of operation of the device.

The closest known technical solutions is the gripping module (see Russian patent No. 2256549 "Gripping head", Sysoyev SN, Zhirov M.Yu.), where excess air pressure is also used for power supply. The gripping module consists of a gripping head (suction cup) and a drive for its vertical movement, made in the form of a single-acting pneumatic cylinder, and the piston cavity is connected to the discharge line through a distributor and to the atmosphere through a safety valve. The suction cup is made pumpless with a working chamber connected to the atmosphere through a distributor.

The use of known pump-free gripping heads in these gripping modules (see Sysoev S.N., Bakutov A.V., Privedenets I.A. "Design of high-speed vacuum grippers", STIN Journal, 2007, No. 12, p.15- 19; RF patent No. 2304505 "Vacuum gripping head", Sysoev S.N. et al., Published on 08.20.2007 at BI No. 23; RF patent No. 2317452 "Vacuum gripping head", Sysoev S.N. et al., published on 02/20/08 in BI No. 5; RF patent No. 2312762 "Vacuum gripping head", Sysoev S.N. et al., published on 02.20.08 in BI No. 5) improves the speed and reliability of the operations "capture", " let go "and Delije. However, the use in conventional gripping modules as a drive of vertical movement of a suction cup of single-acting pneumatic cylinders of a traditional design, a safety valve limits the amount of vertical movement, reduces the speed and reliability of the module as a whole.

To identify the possibility of improving the known gripping module, the following provision was used: “Different technical objects having the same functional and physical connections can perform the same functions” (see p. 62, Sysoev, S. N. Principles and methods for finding technical solutions. Research method functional-physical relations: monograph / S.N.Sysoev, Vladimirov. state university - Vladimir: Publishing house of the Vladimi. state university, 2007. - 214 p.).

An analysis of the operation of the safety valve and the single-acting pneumatic cylinder revealed that the piston and the pneumatic cylinder body perform the function of sealing the working chamber. The same function and the function of depressurization are performed by the safety valve. If we organize the additional function of depressurization of the working chamber of the pneumatic cylinder by the corresponding interaction of the housing and the piston, then the pneumatic cylinder, in addition to performing its main function, will perform the function of a safety valve.

The objective of the invention is to increase the speed and reliability of the device in the entire range of required values for moving the suction cup by assigning the functions of the safety valve to the power part of the vertical drive of the gripping head and eliminating the dependence of its stroke on the dimensions of the vertical movement drive.

The problem is achieved in that in the proposed device, including a gripping head, mounted on a movable element, spring-loaded with a return spring to the housing in a single-acting pneumatic actuator with a working chamber configured to connect through a distributor with a line of excess air pressure, the working chamber is formed by a body cavity and lid, and the gripping head is mounted on the lid mounted on the housing with the possibility of separation with it.

In addition, to increase the speed, increase the range of the gripping stroke and optimize the operation of the device with various mass products, a permanent magnet can be installed on the housing with the possibility of force interaction with the cover, and the return spring is connected to the rod of a single-acting pneumatic cylinder additionally mounted on the housing, the piston the working cavity of which is connected to the working chamber.

An example implementation of the proposed device is shown in figure 1.

The device consists of a housing 1, a return spring 2, a valve 3, a seal 4, a permanent magnet 5, a cover 6, a product 7, a suction cup 8.

The cavity of the housing 1 is closed by a cover 6 with a seal 4, forming a working chamber of the pneumatic actuator. The cover 6 is spring-loaded with a return spring 2 to the housing 1, on which a permanent magnet 5 is fixed with the possibility of force interaction with the cover 6. The working chamber is made with the possibility of connecting to the pneumatic line an excess air pressure through a controlled valve 3 (control not shown). A suction cup is attached to the lid 8.

The capture module operates as follows.

In the initial position (figure 1, a), since the valve is closed, the working chamber of the pneumatic actuator is not connected to the overpressure line, the suction cup occupies the highest position.

At the command "take the product" (Fig. 1, b), valve 3 opens, connecting the pneumatic line of the excess air pressure with the working chamber of the pneumatic actuator. In it, excess air pressure rises and potential energy accumulates. The force increases from the pressure acting on the gap of the cover 6 from the housing 1. When the forces holding the cover 6 are exceeded, it moves in the direction of the product 7 (Fig. 1, c). The valve 3 is turned off. Suction cup 8 reaches the surface of the product 7 and, continuing to move in the same direction due to inertial forces, is deformed (Fig. 1, d), forcing air out of its working cavity. The product capture function is performed. Then the return spring begins to act, moving the cover 6, the suction cup 8 with the part 7 in the direction of the housing 1 (Fig. After connecting the cover 6 with the housing 1, the product occupies its highest position and the process of "taking the product" ends.

An example implementation of the gripping module, with the installation of an additional pneumatic cylinder designed to automatically change the force of action of the return spring during operation, is shown in figure 2.

The gripping module consists of a housing 1, a return spring 2, a controlled valve 3 (control not shown), a seal 4, a permanent magnet 5, a cover 6, a product 7, a gripping suction cup 8 with a lever 9 fixed on its peripheral surface, cables 10, bypass elements 11, the guide 12 and the single-acting pneumatic cylinder 13. The cavity of the housing 1 is closed through the seal 4 by the cover 6, forming a working chamber. The cables 10 are connected at one end to the cover 6 and at the other end to a return spring 2 fixed to the rod of the pneumatic cylinder 13, the piston cavity of which is connected by a pneumatic line to the working chamber and, through valve 3, to an air overpressure pneumatic line. A guide 12 is mounted on the lid 6.

The device operates as follows.

In the initial position (Fig. 2, a), the valve is closed, the working chamber and the piston cavity of the pneumatic cylinder are disconnected from the pneumatic line of excess air pressure, the piston of the pneumatic cylinder occupies the extreme right position, pulling the return spring, creating an effort to press the cover against the housing through the cables. The suction cup is in its highest position.

At the command "take the product" (figure 2, b), the valve opens, connecting the pneumatic line of excess air pressure with the working chamber of the pneumatic actuator and the piston cavity of the pneumatic cylinder. They increase the excess air pressure and accumulate potential energy. The pressure force acting on the gap between the cover and the body increases. The piston of the pneumatic cylinder moves to the left, weakening the spring tension. When exceeding the forces holding the cover, it moves in the direction of the product (Fig.2, c). The valve turns off. The suction cup reaches the surface of the product and, continuing to move in the same direction due to inertial forces, is deformed, displacing air from its working cavity. In this case, the lever 9 does not have a force effect from the side of the product. The product capture function is performed. The piston of the pneumatic cylinder moves to the right, additionally pulling the return spring 2. The return spring moves the lid and suction cup with the product towards the body. The guide 12 contributes to the implementation of the required orientation of the cover relative to the housing (figure 2, g). After connecting the cover to the body, the product takes its highest position and the “take the product” process ends.

By the command “install the product” on the working surface, the gripping module performs the same actions as were performed when taking the product. The difference is that when the product approaches the working surface, the lever 9 initially interacts with it. This force interaction leads to the fact that the edge of the suction cup is diverted from the surface of the product, its working cavity is depressurized, that is, the operation of releasing the product by the suction cup is performed.

Improving the speed and reliability of the device with a significant increase in the range of values of movement of the suction cup is achieved by:

- perform a movable element that is disconnected from the housing of the drive moving the capture;

- the use of a permanent magnet, the magnetic field of which allows you to increase the potential energy of compressed air in the working chamber;

- changes in the characteristics of the force acting on the movable element from the side of the return spring in the process of lowering and lifting it.

At Vladimir State University, a working model of the gripping module was made (Fig. 3). Field tests have shown its efficiency and effectiveness. Compared with similar devices several times increased speed and maximum working stroke capture. For example, the operation “take” the product (lowering the capture, capture of the product, lifting) weighing 100 g from a distance of 200 mm is carried out in less than 0.1 second.

Claims (3)

1. A gripping module comprising a housing, a gripping head in the form of a deformable suction cup, a return spring and a single-acting pneumatic actuator, the working chamber of which is connected through a valve to an air overpressure pneumatic line, characterized in that it is provided with a cover spring-loaded to the housing with a return spring to form a working spring the pneumatic drive chamber, while the suction cup is equipped with a lever for installing the captured part and is mounted on the cover, which is mounted on the housing with the possibility of separation from its movement m in the direction of the gripping parts due to the action of inertial forces in the direction of the body - due to the return spring. 2. The gripping module according to claim 1, characterized in that a permanent magnet is mounted on the housing with the possibility of force interaction with the cover. 3. The gripping module according to claim 1, characterized in that the return spring is connected to the rod of a single-acting pneumatic cylinder additionally mounted on the housing, the piston working cavity of which is connected to the working chamber.

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