CN104608143A - Flexible parabola-shaped abnormal plate spring framework joint - Google Patents

Abstract

The invention relates to a flexible parabola-shaped abnormal plate spring framework joint, and belongs to the technical field of application of robots and mechanical arms. According to the joint, an abnormal plate spring is used as a framework, the joint is bent through the drive of fluid, and the joint can be used as various joints of a robot. When an elastic corrugated pipe is inflated, the elastic corrugated pipe extends and is restrained by the plate spring to be bent towards one side of the plate spring. When gas in the elastic corrugated pipe is released, the joint is restored to be in an extension state under the effect of the plate spring. The pressure in the elastic corrugated pipe is controlled to enable the joint to be bent and to be kept at a certain angle. The elastic corrugated pipe has good flexibility, the plate spring has good elasticity, and therefore the joint has good flexibility. Through the improvement of the cross section of the plate spring, the bending space can be increased, the strength demand can be met, the flexibility is improved, and plate spring materials are saved. The flexible parabola-shaped abnormal plate spring framework joint is flexible in bending action, small in energy consumption, convenient to control and has a good flexible adaptability effect.

Description

Parabolic special-shaped leaf spring skeleton compliant joints

Technical field:

The present invention relates to a parabolic special-shaped leaf spring frame compliance joint, which is a patent application (invention name: variable cross-section and special-shaped leaf spring skeleton compliance joint, application number: 201110406737.X, application date: December 09, 2011) divisional application. This curved joint has good flexibility and controllability, and can be used as various joints of robots, especially for flexible mechanical fingers composed of multiple curved joints. As the actuator of automation equipment, it belongs to the application technology of robots and manipulators. field.

Background technique:

Before the present invention, the bending joints of robots were mostly driven by motors, which had good static stiffness and high control precision, but required complex deceleration devices, which were relatively large in size and not flexible enough; some were driven by pneumatic cylinders or hydraulic cylinders, which required complex fluids loop and the position control accuracy is not high. The current robot joints mostly use rigid skeletons, which require high precision in position and force, but poor flexibility and adaptability, especially when used as mechanical fingers, which cause great physical trauma to the grasping object.

Patent CN200410065130.X proposes a leaf spring skeleton flexible joint with an axially expanded artificial muscle as the driving force. The joint is bent by overcoming the resistance of the plate spring through the expansion of the muscle, and has certain compliance and adaptability. It is used as A good grasping effect can be achieved when using mechanical fingers. Disadvantages: (1) Joint action space is small, and its bending angle is greatly limited. If the distance between the leaf spring and the artificial muscle is small, the artificial muscle will interfere with the leaf spring after bending at a certain angle, which will affect its further deformation; if the distance between the two is large, the joint size will be larger, and the axial extension of the artificial muscle at the same angle As the length increases, the mechanical parameters and material properties of artificial muscles are strictly required. (2) The force of the leaf spring is uneven. Using a general equal-section leaf spring will not only increase the deformation resistance and waste energy, but also increase the weight of the joint and waste materials. (3) Poor flexibility. The superiority of flexibility is reflected in reducing assembly time, simplifying the manufacturing process, improving precision, increasing reliability, reducing maintenance, and reducing quality. The patent has many parts and lacks necessary positioning measures. The bellows are connected by clamps, which is reliable The performance is not high and the replacement is troublesome, which is not conducive to maintenance. (4) The dynamic response needs to be improved. Generally, the constant-section leaf spring has a large resistance when it starts to bend from a straight state, and requires a large pressure to start to move. Moreover, the overall mass of the joint is large and the inertia is large, so the dynamic response needs to be improved.

Invention content:

The present invention aims at above-mentioned deficiency, has adopted the plate spring of variable cross-section and special-shaped as flexible skeleton. The length and thickness of the variable-section leaf spring remain unchanged, and the width changes according to the stress of the leaf spring in a certain order, which conforms to the force distribution of the leaf spring. On the basis of satisfying the strength, the material is saved, the quality is reduced, and the dynamic response is improved. The leaf spring with variable cross-section has wider ends and a thinner structure in the middle, which is easier to deform, has less deformation resistance, and is more flexible in action. The special-shaped leaf spring can effectively avoid the contact interference between the elastic bellows and the leaf spring after the joint is greatly deformed, and greatly improves the working space of the compliant joint. At the same time, necessary positioning measures are adopted between the joint parts to avoid joint torsional deformation caused by low assembly precision and to facilitate the analysis and calculation of stress and deformation. The elastic corrugated pipe adopts the pipe joint form, which is convenient for installation and replacement. The joint can not only be used alone, but also can be assembled into a multi-joint manipulator, a manipulator, etc., and has good coordination.

Main solution of the present invention is realized like this:

Solution 1: As shown in Fig. 1-3, the structure of both ends of the elastic bellows 10 is similar to that of a hydraulic rubber tube. The two ends of the elastic bellows 10 are fixed on the pipe joint 8 through the outer pressure ring 9, and the pipe joint 8 is respectively connected with the headstock 5 and the tailstock 11, locked by the lock nut 7, and sealed by a sealing gasket 6 in the middle. The parts form a sealed cavity that acts as an inflated artificial muscle.

Tailstock 11 is shown in Figure 4-5, has air inlet on it, and air inlet pipe joint 13 is fixed on the tailstock 11 through sealing ring 12. The headstock 5 and the tailstock 11 are respectively fixed with the head section 1 and the tail section 14 through the adjustment cushion block 4 .

As shown in Figure 6-7, the adjustment pad 4 has positioning pin holes on its upper and lower sides to ensure the mutual positioning between the headstock 5, the head section 1, the tailstock 11, the tail section 14 and the adjustment pad 4.

As shown in FIG. 2 , the two ends of the trapezoidal side plate spring 15 a are embedded in the notches and the middle part is a left-right symmetrical trapezoidal side, and any cross section thereof is rectangular. As shown in FIG. 3 , the two ends of the trapezoidal side plate spring 15 a are respectively embedded in the notches of the head section 1 and the tail section 14 , and are fixed with bolts 3 and rectangular gaskets 2 .

The effect of adjusting the positioning pin hole of spacer 4, the notch of head section 1 and tail section 14 is to fix with bolt 3 and rectangular spacer 2 after the front, back, left, and right positions. Namely: Make the headstock 5, the head section 1, the tailstock 11, the tail section 14, the adjustment pad 4, and the trapezoidal side plate spring 15a coplanar with the axial center line of the elastic bellows 10 on the longitudinal symmetry plane, so as to avoid torsional deformation of the joints , and facilitates force and deformation analysis.

Solution 2: As shown in FIG. 8 , the structure of both ends of the elastic bellows 10 is similar to that of a hydraulic rubber tube. The two ends of the elastic bellows 10 are fixed on the pipe joint 8 through the outer pressure ring 9, and the pipe joint 8 is respectively connected with the headstock 5 and the tailstock 11, locked by the lock nut 7, and sealed by a sealing gasket 6 in the middle. The parts form a sealed cavity that acts as an inflated artificial muscle. There is an air inlet on the tailstock 11, and the air inlet pipe joint 13 is fixed on the tailstock 11 through the sealing ring 12. The headstock 5 and the tailstock 11 are respectively fixed with the head section 1 and the tail section 14 through the adjustment cushion block 4 .

As shown in FIG. 9 , the two ends of the parabolic edge leaf spring 15 b are embedded in the notches and the middle part is a symmetrical parabolic edge, and any cross section thereof is rectangular. The two ends of the parabolic edge leaf spring 15b are respectively embedded in the notches of the head section 1 and the tail section 14, and are fixed with bolts 3 and rectangular gaskets 2.

Above-mentioned scheme one, scheme two are the compliant joints of variable-section leaf springs.

Solution 3: As shown in Fig. 10-11, the structure of both ends of the elastic bellows 10 is similar to that of a hydraulic rubber tube. The two ends of the elastic bellows 10 are fixed on the pipe joint 8 through the outer pressure ring 9, and the pipe joint 8 is respectively connected with the headstock 5 and the tailstock 11, locked by the lock nut 7, and sealed by a sealing gasket 6 in the middle. The parts form a sealed cavity that acts as an inflated artificial muscle. There is an air inlet on the tailstock 11, and the air inlet pipe joint 13 is fixed on the tailstock 11 through the sealing ring 12. The headstock 5 and the tailstock 11 are respectively fixed with the head section 1 and the tail section 14 through the adjustment cushion block 4 .

A trapezoidal special-shaped leaf spring 15c whose longitudinal section is trapezoidal, whose arbitrary cross section is rectangular, and whose two ends are embedded in the notches are rectangular, respectively embedded in the notches of the head section 1 and the tail section 14, and bolts 3 and rectangular gaskets 2 fixed.

Solution 4: As shown in Fig. 12-13, the structure of both ends of the elastic bellows 10 is similar to that of a hydraulic rubber tube. The two ends of the elastic bellows 10 are fixed on the pipe joint 8 through the outer pressure ring 9, and the pipe joint 8 is respectively connected with the headstock 5 and the tailstock 11, locked by the lock nut 7, and sealed by a sealing gasket 6 in the middle. The parts form a sealed cavity that acts as an inflated artificial muscle. There is an air inlet on the tailstock 11, and the air inlet pipe joint 13 is fixed on the tailstock 11 through the sealing ring 12. The headstock 5 and the tailstock 11 are respectively fixed with the head section 1 and the tail section 14 through the adjustment cushion block 4 .

The longitudinal section is a parabola-shaped special-shaped leaf spring 15d, and its arbitrary cross-section is a rectangle, and the parts embedded in the notches at both ends are rectangles, which are respectively embedded in the notches of the head section 1 and the tail section 14, and bolts 3 and rectangular Spacer 2 is fixed.

Above-mentioned scheme three, scheme four are the supple joints of special-shaped leaf springs.

Compared with the prior art, the present invention has the following advantages:

Variable cross-section leaf spring skeleton Supplement joints adopt variable width variable cross-section leaf springs, which conform to the distribution of stress. The shape with a narrow middle and wide ends is easier to deform, which reduces deformation resistance, saves energy, and reduces joint quality. , saving materials, making the joint movement more flexible and dynamic responsiveness better.

The special-shaped leaf spring skeleton compliant joint effectively avoids the problem of contact interference between the elastic bellows and the leaf spring after the large deformation of the joint, and greatly improves the working space of the compliant joint.

At the same time, necessary positioning measures are adopted between the joint parts to avoid the torsional deformation of the joint caused by low assembly accuracy, and to facilitate the analysis and calculation of stress and deformation; the elastic bellows are in the form of pipe joints, which are easy to install and replace; The spacer can easily change the bending moment of the leaf spring.

Description of drawings:

Fig. 1 is the front view of the flexible joint scheme 1 of the present invention

Fig. 2 is the A-A sectional view of the first front view of the flexible joint scheme of the present invention

Fig. 3 is the B-B sectional view of the first front view of the flexible joint scheme of the present invention

Fig. 4 is the front view of tailstock 11 parts in the supple joint of the present invention

Fig. 5 is the left side view of tailstock 11 parts in the supple joint of the present invention

Fig. 6 is a top view of the parts of the adjustment pad 4 in the compliance joint of the present invention

Fig. 7 is the C-C cross-sectional view of the top view of the adjustment pad 4 parts in the compliant joint of the present invention

Fig. 8 is the front view of the second flexible joint solution of the present invention

Fig. 9 is a D-D cross-sectional view of the second front view of the flexible joint solution of the present invention

Fig. 10 is the front view of the third flexible joint solution of the present invention

Fig. 11 is the E-E cross-sectional view of the three front views of the flexible joint solution of the present invention

Fig. 12 is the front view of the fourth flexible joint solution of the present invention

Fig. 13 is the F-F sectional view of the four front views of the flexible joint solution of the present invention

Fig. 14 is a schematic diagram of the working principle of the compliance joint scheme 1 of the present invention

Detailed ways:

Below the present invention is further described in conjunction with the scheme one implementation in accompanying drawing 14:

In Scheme 1, the two ends of the elastic bellows 10 are fixed on the pipe joint 8 through the pressure piece 9, and the pipe joints 8 at both ends of the bellows are respectively connected with the headstock 5 and the tailstock 11, and are locked by the lock nut 7, with a Gasket 6 is sealed to form a gas cavity. There is an air inlet on the tailstock 11, and the air inlet pipe joint 13 is fixed on the tailstock 11 through the sealing ring 12. The headstock 5 and the tailstock 11 are respectively fixed with the head section 1 and the tail section 14 through the adjustment cushion block 4 . There are positioning pins on the upper and lower surfaces of the adjustment cushion block 4 to ensure the mutual positioning between the headstock 5 and the head section 1 as well as the tailstock 11 and the tail section 14. The two ends of the trapezoidal side plate spring 15a are respectively embedded in the notches of the head section 1 and the tail section 14, and are fixed with bolts 3 and rectangular gaskets 2. The gas source is connected with the intake pipe joint 13, and the gas enters the cavity through the intake pipe joint.

When working, the bending angle of the joint is controlled by controlling the cavity pressure in the elastic bellows. When the air is inflated into the cavity, the pressure in the cavity increases, and the elastic bellows elongates in the axial direction. Because one side of the bellows is constrained by the plate spring and cannot elongate, the joint is bent by overcoming the resistance of the plate spring; when the pressure in the cavity decreases, the joint is Straighten under the restoring force of the leaf spring. The joint has good compliance, adaptability and controllability, and can be constructed into a mechanical finger and combined into a single-degree-of-freedom or multi-degree-of-freedom manipulator. Taking the single-joint three-finger manipulator as an example, the tail joint is connected to the palm of the robot, and the head joint is connected to the tip of the robot finger. The fingertip can be designed into an optimal curve and select the best grasping position according to the different objects to be grasped. In order to reduce the effect damage, cushioning media such as rubber pads can be wrapped on the mechanical fingertips. When grabbing an object, inflate the cavity, bend the three fingers at the same time to grab the object, keep the pressure constant after getting a certain grasping force, and maintain the grasping state; when releasing the grasped object, open the exhaust valve, and the pressure in the cavity will drop , the finger releases the object under the restoring force of the plate spring.

Claims (1)

1. The flexible joint of the parabolic special-shaped leaf spring skeleton is characterized in that: the two ends of the elastic bellows (10) are fixed on the pipe joint (8) through the outer pressure ring (9), and the pipe joint (8) is respectively connected to the head seat ( 5) It is connected to the tailstock (11), locked by the lock nut (7), and sealed by a sealing gasket (6) in the middle. These parts form a sealed cavity, which is used as an expanded artificial muscle; The air inlet, the air inlet pipe joint (13) is fixed on the tailstock (11) through the sealing ring (12); the headstock (5) and the tailstock (11) are respectively connected with the head section (1) and the tail section (14) are fixed; wherein, the leaf spring skeleton is: a parabolic special-shaped leaf spring (15d) with a parabolic longitudinal section is respectively embedded in the notches of the head section (1) and the tail section (14), and bolts ( 3) Fixed with the rectangular spacer (2), the longitudinal section is a parabolic special-shaped leaf spring (15d), the part embedded in the notch at both ends is rectangular, and any cross section thereof is rectangular.