CN105291125A - Screw driving hand mechanism of robot and clamping method - Google Patents

Abstract

The invention relates to a screw transmission hand mechanism and a clamping method of a robot, which belong to the robot hand mechanism and the clamping method. The hand mechanism has two fingers, and the screw rod has two sections of threads, left and right, which respectively form two screw pairs with the two fingers, and the two screw pairs correspond to the rotation of the screw rod and the simultaneous movement of the two fingers; The thread of the screw pair means that the two threads of the screw have opposite directions and the same pitch; the relative position of the two fingers is determined by the size of the clamped object. The two threads of the screw are standardized single-start threads, and the journals at both ends of the screw The support is matched; the object clamping method: the screw threads of the two sections of the screw are right-handed and left-handed respectively, and the two fingers always move in the opposite direction during the movement, that is, move toward each other or back to achieve clamping or loosening. Advantages: The structure of the hand mechanism is relatively simple and compact, the clamping is convenient and reliable, the versatility is good, and there is no clamping error when clamping objects of different sizes. The screw rod rotates left and right to two sections of threads, and the screw mechanism has good self-locking performance.

Description

A screw drive hand mechanism and clamping method of a robot

technical field

The invention relates to a robot hand mechanism and a clamping method, in particular to a robot screw drive hand mechanism and a clamping method.

Background technique

Robots are more and more widely used in all walks of life. It is an open chain multi-degree-of-freedom mechanism. The mechanical mechanism of the robot consists of: hand, wrist, arm and fuselage, among which the robot hand is an important part of the robot's operation, and it is the end effector of the robot. Robotic hands mainly include clamping hands, adsorption hands and human-like hands. Clamp-type hands are one of the more commonly used clamping hands, and their function is to realize the clamping of objects. Clamp-type hands are further divided into rotary-type and translation-type hands according to the clamping movement mode. For industrial robots, there are generally high positioning accuracy requirements. In order to broaden the application range of the robot, the robot clamp-type hand is generally used to clamp objects or objects within a certain size range. In this way, a clamping error may occur during the clamping process, and this error directly affects the robot. positioning accuracy.

The clamp type hand is generally composed of fingers, a transmission mechanism, a driving device and the like. In general, the robot's hand has two fingers, and in special cases, the hand has three or more fingers, such as a five-fingered dexterous hand. Their structural form mainly depends on the shape and characteristics of the clamped object.

The function of the transmission mechanism is to transmit motion and power to the fingers to achieve clamping and loosening actions. There are many forms of transmission mechanisms. Fingers and transmission mechanisms are generally composed of levers, wedges, chutes, and connecting rods. That is to say, the composition of the robot hand is mainly composed of composite mechanisms, that is, hand mechanisms .

For the design of the clamp-type rotary hand mechanism of the robot, not only the simple structure, small size, suitable clamping force and driving force must be considered, but also the hand mechanism must meet a certain positioning accuracy during the clamping process. Rotary hand mechanisms can produce gripping errors when gripping objects of different sizes.

An effective way to improve the clamping accuracy of the rotary hand mechanism is to adjust the structure of the corresponding hand or replace the hand. At this time, it may be necessary to configure an adapter with a quick loading and unloading function. The adapter consists of Composed of two parts, namely the adapter socket and the adapter plug, they are installed on the wrist and the end effector respectively, but the corresponding hand becomes very complicated in structure.

The clamp-type rotary hand mechanism realizes the clamping or loosening of the object through the transmission mechanism to drive the fingers to rotate. Its main disadvantage: there are clamping errors in the process of clamping objects of different sizes, and the required driving force is relatively large.

The clamp-type translational hand mechanism realizes the opening or closing action of the fingers through the linear reciprocating motion or plane movement of the finger surface. There are not many forms of translational hand mechanisms. Its disadvantages: the structure is more complicated, the driving force required is very large, generally a hydraulic system is required, the cost is high, and its application is limited.

In conclusion, although the robot's rotary hand mechanism is relatively simple, there will be clamping errors when clamping objects of different sizes. The translational hand mechanism is usually used to clamp objects with parallel planes. Several common translational hands are not very versatile in terms of versatility, and their structures are more complicated, especially the linear translational hand structure is more complicated. . The realization of the two types of hand structures generally requires a hydraulic drive system, which is costly and requires a large driving force.

Contents of the invention

The purpose of the present invention is to provide a screw drive hand mechanism and clamping method of a robot, to solve the problems of clamping errors in the rotary hand mechanism and the complexity of the translational hand mechanism, and to solve the needs of these two types of hand structures. The problem of configuring a hydraulic drive system is high cost and requires a large drive force.

The purpose of the present invention is achieved like this: the hand mechanism has two fingers, and the screw rod has left and right two sections of threads, which form two screw pairs with the two fingers respectively, and the two screw pairs are all corresponding to the rotation of the screw rod, The two fingers move separately at the same time; the threads of the two helical pairs, that is, the two sections of the screw, have the opposite direction of rotation and the same pitch; the relative position of the two fingers is determined by the size of the clamped object, and the two sections of the screw thread are standardized single-head Screw threads, the journals at both ends of the screw are matched with the supports.

The screw rod is a screw rod with two sections of screw threads with opposite directions and equal pitches.

Object clamping method: the screw threads of the two sections are right-handed and left-handed respectively, and the two fingers always move in the opposite direction during the movement to achieve clamping or loosening; when the release is realized, the screw reverses, through two Driven by a screw pair, the two fingers move in opposite directions to both ends of the screw to open the fingers; when the object needs to be clamped, the screw rotates forward, and through the left and right two screw pairs, the two fingers move towards each other to clamp Object; assuming that the screw pitch of the two sections of the screw is t, when the screw rotates the angle θ, the total translation distance of the two fingers of the hand mechanism is

$\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}\mathrm{<span\; class="notranslate">\; t</span>}$

In the formula: θ——screw rotation angle;

t——the pitch of the two threads of the screw;

l—the total translation distance of the two fingers.

Beneficial effect, due to the adoption of the above scheme, when the screw rotates forward in one direction, if the first finger and the second finger move toward each other to clamp the object, then when the screw reverses in the other direction, the first finger moves to the left end of the screw, The second finger moves in the opposite direction towards the right end of the screw causing the object to be released. The screw drive hand mechanism and clamping method well solve the problems existing in the existing clamp-type hand mechanisms, and avoid the shortcomings of the above two types of clamp-type hand mechanisms.

It solves the problems that the two types of hand structures need to be equipped with a hydraulic drive system, the cost is high, and the driving force is relatively large, and the purpose of the present invention is achieved.

Advantages: The corresponding structure of the hand mechanism is relatively simple and compact, the clamping is convenient, reliable, and has good versatility, and there is no clamping error when clamping objects of different sizes. The left and right screw threads of the screw are designed according to the standardization, and the parameters of the screw drive are reasonably designed, so that the screw mechanism has good self-locking performance. The clamping force and clamping stroke of the hand mechanism are relatively large.

Description of drawings:

Fig. 1 is the mechanism diagram of the screw drive hand of the present invention.

In the figure, 1, the first finger; 2, the object; 3, the second finger; 4, the screw.

detailed description

Embodiment 1: The hand mechanism has two fingers, and the screw rod has two sections of threads, left and right, respectively forming two screw pairs with the two fingers, and the two screw pairs correspond to the rotation of the screw rod, and the two fingers simultaneously Move separately; the threads of the two screw pairs, that is, the two sections of the screw, have the opposite direction of rotation and the same pitch; the relative position of the two fingers is determined by the size of the clamped object. The end journal is matched with the bearing.

The screw rod is a screw rod with two sections of screw threads with opposite directions and equal pitches.

Object clamping method: the screw threads of the two sections of the screw are right-handed and left-handed respectively, and the two fingers always move in the opposite direction during the movement to achieve clamping or loosening; when the loosening is achieved, the screw 4 reverses and passes Driven by two helical pairs, the two fingers move oppositely to both ends of the screw to open the fingers; when the object needs to be clamped, the screw 4 rotates forward, through the left and right two helical pairs, the two fingers move towards each other Hold object 2. Assuming that the screw pitch of the two sections of the screw is t, when the screw rotates the angle θ, the total translational distance of the two fingers of the hand mechanism is

$\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}\mathrm{<span\; class="notranslate">\; t</span>}$

In the formula: θ——screw rotation angle;

t——the pitch of the two threads of the screw;

l—the total translation distance of the two fingers.

The structure of the invention is easy to realize. According to the requirements of use, standardized threads are selected for the structure of the screw pair, and the matching material and the helix angle of the screw pair are reasonably selected to realize the self-locking condition of the screw pair. First two fingers, the first finger 1 and the second finger 3 are respectively installed on the two threads of the screw rod, and then the screw rod is installed on the supports at both ends.

Both ends of the screw are supported in the form of sliding bearings, and one end of the screw 4 can be directly connected to the configured control motor shaft or connected to the control motor shaft through a coupling. The whole hand mechanism is connected with the robot wrist through the bearing seat and the like.

Claims (2)

1. the worm drive hand organization of a robot, it is characterized in that: this hand organization has two fingers, described screw rod has left and right two sections of screw threads, points formation two screw pairs respectively with two, and two screw pairs all correspond to bolt rotary, two fingers move simultaneously respectively; On the contrary, pitch is equal for the screw thread of two screw pairs and two of screw rod sections of thread rotary orientations; The relative position of two fingers is determined by the size of held object, and screw rod two sections of screw threads all adopt standardized one start screw, and screw rod two ends axle journal matches with supporting;

Described screw rod is two sections of screw rods that thread rotary orientation is contrary, pitch is equal.

2. the clamp method of the worm drive hand organization of a kind of robot according to claim 1, it is characterized in that: object clamp method: screw rod two sections of thread rotary orientations are respectively dextrorotation and left-handed, two fingers are always oppositely mobile and realize clamping or unclamp in motion process; When realizing unclamping, screw rod reverses, and by two screw pair transmissions, two fingers oppositely move respectively to screw rod two ends and spread one's fingers; When needs gripping objects, screw rod rotates forward, and by left and right two screw pair transmissions, two fingers move and gripping objects in opposite directions; If screw rod two sections of thread pitch are t, when bolt rotary θ angle, hand organization two is pointed total translation distance and is

$l=\frac{\mathrm{\&theta;}}{2\mathrm{\&pi;}}(t+t)=\frac{\mathrm{\&theta;}}{\mathrm{\&pi;}}t$

In formula: θ---screw rod corner;

The pitch of t---screw rod two sections of screw threads;

L---the translation distance that two fingers are total.