JPS60234105A - Driver with elastic contracting member - Google Patents

Abstract

PURPOSE:To shorten the time taken for decline of the vibration of the driver, by arranging two springs which act in the opposite direction of each other on the passage of the driving force from one end to the other end of the elastic contracting member. CONSTITUTION:A spring 24 is arranged in an elastic contracting member 1 so that its force will by exerted in the direction of contraction of the tube member 11. Thus, the rigidity of the elastic contracting member 1 is increased by the force exerted by the spring 24 and the natural frequency of the elastic contracting member 1 is increased. As a result, the time taken decline of the vibration of the driver can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a drive device using an elastic contractile body used, for example, in a servomechanism that controls the angle of the arm of a pneumatic robot.〇 (Prior art) Radioactive material The manipulator (Magic Hand) was developed to operate through the shielding wall of a so-called hot cell, which is surrounded by a HI wall to prevent radioactive contamination during storage, refilling, distribution, and other experiments and processing. With the development of robot technology, the use of robots is expanding rapidly in a wide range of applications, including replacing manual labor. There are various types of actuators that operate such manipulators, but since sparks are unavoidable with motors, especially electric ones, pneumatic types are preferably used when there is a need for explosion protection. Most of the pneumatic actuators in the market are of the so-called air cylinder type, but since the cylinder piston assembly is usually made of metal, it often has the disadvantage of being heavy in comparison to the operating force. On the other hand, an elastic contractile body known as an air bag type pneumatic actuator is one in which the outer periphery of an elastic member having a cavity inside is surrounded by a braided structure made of a high-tensile material, and pressure is applied to the inner cavity of the elastic member. This is a leather product that utilizes the effect of contraction in the axial direction due to the bank graph effect of the suction/contraction assembly structure, which expands in diameter by adding .

This type of elastic contractile body is lightweight, does not include any sliding parts, so there is no need to worry about the effects of frictional force or air leakage, and it can obtain a full working force that is about 10 times that of an air cylinder type pneumatic actuator. There are advantages.

For this reason, recently, drive devices using elastic contracting bodies are often used as drive devices for servo mechanisms that fully drive the manipulator.For example, when controlling the rotation angle, one end of each drive device is completely fixed. The other ends of the two elastic contracting bodies are connected by a wire wrapped around a pulley, and the pulley is rotated by the difference in pressure applied to the two elastic contracting bodies, until all of the arms connected to the pulley fit into a predetermined position. In this case, the rotation angle of the pulley is determined by detecting the entire rotational position using a position sensor and performing feedback control to accurately stop the pulley at a predetermined position.

(Problem to be Solved by the Invention) However, the conventional drive device using an elastic contracting body has low rigidity, and the vibrations generated when the elastic contracting body operates subsides until the pulley stops at a predetermined position. It takes a lot of time. Furthermore, if the operating speed is increased or if the length of the arm connected to the boot is increased, this time will become even longer. Conventionally, the rigidity of the servo mechanism was increased by increasing the position feedback gain in order to completely shorten the time it takes for the pulley to stop at a predetermined position, but this also had certain limitations.

(Means for Solving All Problems) The object of the present invention is to provide a driving device ffi' using an elastic contractile body that can solve the above-mentioned conventional problems. Focusing on increasing the natural frequency of the drive device using the elastic contractile body, this aims to shorten the time during which the vibrations of the drive device are attenuated. The device includes two elastic contracting bodies each fully fixed at one end, a connecting member connecting the other ends of these elastic contracting bodies, and a driven member driven by the connecting member, In the driving device which fully drives the driven member by expansion and contraction due to changes in the internal pressure of the contracting body, it is preferable that two springs acting in opposite directions are provided in the drive path from one side of the elastic contracting body to the other. I'll close with the characteristics.

(Function) With these two springs acting in opposite directions, it is possible to increase the total unique vibration frequency of the drive device, and the time for the vibrations of the drive device to decay becomes faster.

(Central Example) The driving device using the elastic contracting body of the present invention will be described in detail below with reference to all the drawings.

FIG. 1 is a diagram showing a first embodiment of the present invention.

The two elastic contraction bodies l are connected by a wire 2 which is a connecting member, and this wire 2? The wire 2 is wound around a pulley 8, which is a driven member, and the operation of the elastic contraction body 1 is transmitted to the pulley 8 via the wire 2. 4 is an arm connected to the pulley 8, and 5 is a predetermined member attached to the tip of the arm number.

Figure 2 is a cross-sectional view showing the structure of the elastic contraction body l shown in Figure 1. In Figure 2, 1 indicates the entire elastic contraction body, 111 is a tubular body, and 12 is a braided reinforcement on its outer periphery. Structure: 1B is a closing member at both ends, 14 is a caulked cap. The tubular body 11 can be made of rubber or a rubber-like elastic material in terms of air impermeability and flexibility, but equivalent materials such as It follows the customary practice that various plastics can be substituted, but in that case, the so-called rest angle (54°44') K
Preferably, the initial value of the braiding angle θ is set so that the above-mentioned rest angle is reached at the maximum expansion diameter of the tubular body 11 due to the internal pressure of the tubular body 11, whereas the braiding angle is set to be close. The usage conditions are determined so that the normal strain ε reaches about 0.1 to 0.2 at about 20 degrees.

The tensile reinforcement element used in this braided reinforcement structure 12 is made of organic or inorganic high tensile strength fibers, such as aromatic polyamide fibers (Kepler: trade name), twisted or untwisted bundles of filaments such as ultrafine metal wires, etc. Compatible.

For a fairly low angle arrangement like the initial value of 20° above]
Although the braiding operation on the outer periphery of the tubular body 11 is not necessarily easy, for example, a braided body obtained by a normal rubber hose braiding machine is stretched in the axial direction so as to match the above initial value. It is convenient to cover the outer periphery of the tubular body 11.
Adhesion may be applied to the outer periphery as appropriate.

Furthermore, the outer periphery of this braided reinforcing structure 12 may be provided with a weather-resistant, trauma-resistant protective coating as appropriate. Nipple 15 for sealing bonding that can use adhesive
And positioning? From the controlling flange 10 and the six-digit eye or clevis end 17 in the connecting bottle hole, 'f l11
On the outer periphery of the nipple 15, an annular protrusion 18 is provided to prevent the nipple from being pulled out, forming an acid taper toward the tip with a sharp tip in the opposite direction. At least on one side of the O-closing member 18, there are holes 19' formed in the length direction of the nipple 15 (a total of four connecting holes 21 communicating with the inner cavity 20 of the tubular body 11 through r). Attach the finting 22. A spring 24 is engaged with a retaining rod 28 provided across the hole 19i at the inner end of the nipple 15, and this spring 24 applies a spring force in the direction that the tubular body 11 contracts. let

The caulking cap 14 engages with the flange 16 and covers the outer periphery of the end of the tubular body 11, and in particular has a flare 25 on the end edge.
The closure member 18 is made of a cylindrical metal piece having a cylindrical shape formed therein, and is locally pressed in the radial direction toward the nipple 15 to sealingly bond the closure member 18 to the tubular body 11.

Next, the entire operation will be explained.

(?) The elastic contractile body 1 is connected to the fitting 22 by an operating pressure source (not shown), such as an air compressor, through a conduit containing 80,000 valves, and applies a controlled pressure within the internal cavity 18 of the tubular body 11. Therefore, the braid angle θ of the braided structure 12.

In other words, due to the pantograph movement,
The expansion diameter of the tubular body 11 and the contraction in the transverse direction resulting therefrom, that is, the reduction in the distance between the connecting holes of the closing member 18, are also reduced.

On the other hand, when the control pressure is released, the air in the internal cavity is reduced to 8
Needless to say, the tubular body 1 is released into the atmosphere through the valve, and the tubular body 1 recovers and expands as the braid angle of the braided reinforcing structure 12 decreases. The operation of the entire drive device as a servo mechanism will be explained. First, elastic contraction body IK
Considering the case where no spring is provided, the equation of motion is as follows: OJ#+0>+ksθ=kpΔP ・
...... (1) J: moment of inertia in member 5, o: equivalent viscosity coefficient of pulley 8, ks: spring effect due to the elasticity of the elastic contracting body (8), kp: constant This drive device is a servo mechanism. In order to perform stable position control at high speed, it is necessary to increase ks and keep C at an appropriate level. For this purpose, the position and speed of the pulley 8 may be fed back. In other words, by setting the position feedback gain ik□ and the speed feedback gain to 2, and substituting the target angle of pulley 3 into equation (1), the following equation becomes CJθ + (2 kp for G) θ + (1 kp for k8 +)
) θ=kp k , θ −−−−<2) As is clear from the above equation, the viscosity coefficient and spring constant sound quality can be improved by adjusting Vr− by 2, but due to delays in pressure control, etc.
There is a limit to increasing t.Next, based on the present invention, the equation of motion of the servo mechanism in a state where a spring is provided in the elastic contracting body l is determined as follows.

K here indicates a spring element. The contractile force F of the elastic contractile body 1 is expressed by the following formula: P: pressure, D=initial diameter, θ. : initial cord angle, ε; contraction rate, ε. : Contraction rate O when the spring reaches its natural length The relationship between the contraction force F and the contraction rate ε is shown in FIG. 8. In FIG. 8, the broken line shows the entire elastic contracting body without a spring, and the solid line shows the elastic contracting body provided with a spring metal. Note that a and a' indicate the characteristics when applying an air pressure of lyo/♂, b and b/ are 2 gin/cm2, and 0.0' is 8 gin/α2
All cases are shown when air pressure is applied. In the elastic contractile body equipped with a spring shown by the solid line, the contractile force increases by the amount assisted by the spring, and the increase in contraction rate is small with respect to the increase in contractile force, which means that the amount of movement of the elastic contractile body increases. Since the applied force is increased, the rigidity of the drive device is increased. As a result, the natural frequency of the drive device increases, so the driving time t of the drive device also increases.
The relationship between the angle θ and the angle θ is shown in FIG. The solid line indicates the characteristics of the present invention in which a spring is provided in the drive device, and the broken line indicates the spring? It shows the characteristics of a drive device that is not provided.

As described above, in the drive device f1t of the present invention in which the spring assembly is provided, the natural frequency is high, so the time for the amplitude of the vibration generated during drive to subside is short, so it is possible to control the position of the pulley 8 at high speed and stably. becomes.

A second embodiment of the invention will now be described in detail with reference to FIGS. One end of the spring 26 is hooked to the fixed member 28, the other end is fixed to the entire boot 98, and the other end is hooked to the lifting member 29.This spring 26 is moved in the direction of the arrow in FIG. 6(a). Alternatively, the spring 27 can be hooked at one end to the fixing member 28 and hooked at the other end to the hooking member 80 fixed to the boot IJ8, as shown in detail a in FIG. Fig. 7 is a diagram showing the complete construction of the elastic contracting body l used in the drive device of this embodiment.
11) Deru C has the same structure as the elastic contracting body shown in FIG. 2 except that the hook 28 and spring 24 are not present.

In this embodiment as well, the equation of motion when using this drive device as an all-servo mechanism is the same as the equation (8) above,
Is the rigidity of the drive device equal to the spring force of springs 26 and 27? Since the natural frequency of the drive device can be increased, the same effects as in the above-mentioned embodiments can be obtained.

(Effects) As described in detail above, the drive device using elastic contracting bodies of the present invention is a driving device that drives a predetermined member connected between two elastic contracting bodies by the internal pressure difference between the two elastic contracting bodies. ,
Two springs acting in opposite directions are provided in the drive path from one of the fully elastic contracting bodies to the other.
・Since the rigidity of the elastic contracting body can be increased by the spring force of the two springs and the natural frequency can be increased, the time for the vibrations generated in the drive device to subside during driving is short, so the drive device Position control is fast and stable (12
), and is an extremely effective drive device for use in manipulators that require high production speed and accuracy.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the structure of an embodiment of a drive device using an elastic contractile body of the present invention; FIG. 2 is a partially sectional plan view showing the structure of an elastic contracture body used in the drive device of FIG. Figure 8 is a characteristic diagram showing the relationship between the contraction force and contraction rate of the elastic contraction body in Figure 2 and the conventional elastic contraction body. Figure 4 shows the relationship between the elastic contraction body in Figure 2 and the conventional elastic contraction body. A characteristic diagram showing the relationship between vibration generated during operation and time. Figure 5 is a partially cutaway plan view showing the configuration of another embodiment of the present invention. Figure 6 (a), middle) is shown in Figure 5. FIG. 7 is a partially sectional plan view showing the structure of the elastic contractile body used in the drive device shown in FIG. AG5.6. l... Elastic contraction body 2... Wire 8... Pulley 4... Arm 5... Member 11... Tubular body ■2... Braided reinforcement structure 18... Closing member 14.
...Crimp cap 15...Nipple 16...Flange 17...Crevice end 18...Annular protrusion 1
9... Hole 20... Internal cavity 21... Connection hole 22... Fitting 28... Hanging rod 24... ffne 215
...Flare〇 Patent Applicant Bridgestone Co., Ltd.Heph p L-L Zudenya ΦTo 39 Collection

Claims (1)

[Claims] L comprises two elastic contracting bodies each having one end fixed, a connecting member that fully connects the other ends of these elastic contracting bodies, and a driven member driven by the connecting member, and
In a drive device that drives the driven member by expansion and contraction due to changes in internal pressure of two elastic contracting bodies, two springs acting in opposite directions are connected to a driving path from one elastic contracting body to the other. A driving device using an elastic contracting body.