JP2007040450A - Variable elastic element, joint using the same, vehicle and dynamic vibration absorbing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable elastic element constant in natural length, controllable in the modulus of elasticity, and moreover compact in size. <P>SOLUTION: A variable elastic ring 4 with rigidity changed along a circumferential direction has a toothed belt 6 and a pair of gears 8, 10 arranged inside, and the gears 8 are rotated by a driving motor 12 to change the elasticity of the ring. The elasticity of the variable elastic element 2 which connects arms 13, 14 is thus controlled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable elastic element, a joint using the same, a vehicle, and a dynamic vibration absorber.

  In conventional mechanical engineering, it seems that there is a strong tendency to achieve a desired motion by performing precise control using a highly rigid joint. On the other hand, the inventor has paid attention to the fact that the natural frequency and the natural vibration mode can be controlled, for example, by using a controllable elastic element having a variable elastic modulus. If the natural frequency of the system can be controlled, it can be applied to a dynamic vibration absorber. Further, when the elastic modulus is made variable, the system can be controlled between a state where importance is attached to increasing the rigidity and maintaining a predetermined posture and a state where importance is attached to reducing the rigidity and absorbing shocks. In vehicle engineering or the like, this makes it possible to absorb both vibrations during traveling and to maintain an accurate posture when stopped.

  Furthermore, if variable elastic elements that can change the elastic modulus while keeping the natural length constant are placed on both sides of the joint in a state where the tension is antagonized with pre-tension applied, the position and stiffness of the joint are independent. And become controllable. Therefore, if the elasticity of the left and right variable elastic elements on both sides of the joint body is controlled asymmetrically, the joint rotates, and the joint rigidity can be controlled independently of the joint direction, that is, the rotation angle. Such a joint is effective in realizing a movement that imitates walking and the meandering of a reptile, and can be used for a walking robot and a meandering robot that performs a lizard-like meandering movement. The inventor has completed the present invention based on such an idea.

An object of the present invention is to provide a variable elastic element in which the elastic modulus can be controlled while keeping the natural length constant.
An additional object of the invention of claim 2 is to provide a compact variable elastic element.
An object of the invention of claim 3 is to provide a variable elastic element in which a portion having a large or small rigidity of an elastic body is selected and rotated with respect to a load applied from the outside.
An additional object of the invention of claim 4 is to provide a variable elastic element that can act as a push spring or a pull spring and can rotate the ring reliably and smoothly.
An object of the invention of claim 5 is to provide a joint whose direction and rigidity can be controlled independently.
An object of the invention of claim 6 is to provide a vehicle that absorbs an impact during running and maintains a constant posture when stopped.
An object of the invention of claim 7 is to provide a dynamic vibration absorber in which the natural frequency is made variable in accordance with a change in the vibration target vibration frequency.

The present invention resides in a variable elastic element provided with a ring-shaped elastic body whose rigidity changes along the circumferential direction and a rotating means for rotating the elastic body.
Here, the variable elastic element means a part, member, device, or other mechanical element whose elasticity is variable. The elastic modulus can be changed while keeping the natural length constant. It preferably has a changeable characteristic. For example, the variable elastic element may have a configuration in which bending beams having the same curvature are joined to form a ring (ring), and the rigidity changes depending on the rotation angle.
Preferably, a belt is disposed on the inner periphery of the ring-shaped elastic body, and a transmission vehicle is disposed in the ring as the rotating means to operate the belt.
Particularly preferably, four transmission vehicles are provided as the rotating means, and these are connected by a transmission belt and connected by a pantograph.
Furthermore, the present invention provides a ring-shaped elastic body having at least a portion that gradually decreases from a portion with high rigidity to a small portion along a circumferential direction, and a portion that gradually increases from a portion with low rigidity to a large portion; Rotating means for rotating the elastic body, and control means for controlling the rotating means to change the position of the elastic body so as to correspond to a load applied from the outside.

  The present invention also provides a variable elastic element provided with a ring-shaped elastic body, the rigidity of which varies along the circumferential direction of the ring, and a rotating means for rotating the elastic body. The joint is placed so as to antagonize with pretension applied to both sides of the joint body. Preferably, a belt is disposed on the inner periphery of the ring-shaped elastic body of the variable elastic element, and the belt is operated by disposing a transmission wheel of the rotating means in the ring.

  In addition, the present invention uses a variable elastic element provided with a variable stiffness element along the circumferential direction of the ring and a rotating means for rotating the elastic body for the suspension, and has rigidity during traveling. The vehicle is provided with a control means for controlling the turning means of the variable elastic element so that the rigidity is lowered and the rigidity is increased when stopped. Preferably, a belt is disposed on the inner periphery of the ring-shaped elastic body of the variable elastic element, and the belt is operated by disposing a transmission wheel of the rotating means in the ring.

  Furthermore, the present invention provides a variable elastic element provided with a variable stiffness element in which rigidity changes along the circumferential direction of the ring and a rotating means for rotating the elastic body, The dynamic vibration absorber is provided with a control unit for controlling the rotation unit of the variable elastic element according to the frequency of the vibration. Preferably, a belt is disposed on the inner periphery of the ring-shaped elastic body of the variable elastic element, and the belt is operated by disposing a transmission wheel of the rotating means in the ring.

In the variable elastic element of the present invention, the elastic modulus can be controlled while keeping its natural length constant.
Further, when a belt is disposed inside the ring-shaped elastic body and driven by a transmission vehicle such as a gear or a pulley, the drive mechanism can be accommodated inside the ring-shaped elastic body.
In addition, when four transmission wheels are provided and connected with a transmission belt, and combined with a pantograph, the variable elastic element acts as a push spring and a pull spring, and the ring can be rotated reliably and smoothly. I can do it.

  If a pair of left and right variable elastic elements are arranged on both sides of the joint body so as to antagonize with pretension applied, that is, if a reverse force is applied to the joint body from the left and right variable elastic elements, The direction and rigidity can be controlled independently. For example, this joint is neutral when the elastic moduli of the left and right variable elastic elements are balanced, and when the elastic moduli are unbalanced, the joint rotates left and right. Since the joint stiffness is determined by the sum of the elastic moduli of the left and right variable elastic elements, the joint orientation and stiffness can be controlled independently. Such a joint imitates a joint of an animal and is suitable for a walking robot, a meandering robot, or a working robot that performs the same work as a human.

  The variable elastic element of the present invention is used as a vehicle suspension to reduce rigidity when traveling to prevent vibration from being transmitted to the loading platform or superstructure. Otherwise, a vehicle that achieves both the absorption of vibration during traveling and the stability of the posture during stopping can be obtained. The vehicle may be a passenger car, a train, or the like in addition to the transport carriage of the embodiment.

  Further, when the variable elastic element of the present invention is used as an elastic element of a dynamic vibration absorber, the natural frequency of the dynamic vibration absorber can be controlled in accordance with the vibration frequency of the vibration damping object, and vibration can be efficiently suppressed. This dynamic vibration absorber can be used for vibration absorption of conveying equipment such as a stacker crane, vibration absorption of precision equipment, machine tools, vehicles, and the like.

  In the following, an optimum embodiment for carrying out the present invention will be shown.

  An example is shown in FIGS. In the drawings, the same reference numerals denote the same elements. As examples of the variable elastic element, the variable elastic element 2 in FIG. 1, the variable elastic element 22 in FIG. 3, and the variable elastic element 32 in FIG. Here are two examples. 5 to 7, any of these variable elastic elements 2, 22, 32 may be used. Further, a symbol with 'represents the same symbol without'.

  In the variable elastic element 2 of FIG. 1, the variable elastic ring 4 includes a variable elastic ring 4 made of a synthetic resin elastic body made of, for example, a fluoride polymer, and the material thereof matches the elastic modulus required for the element 2. To select. The ring 4 is rotated by scraping the inner surface of the ring 4 to provide the transmission belt 6, meshing with the gears 8 and 10, and rotating the gear 8 by the drive motor 12. Reference numerals 13 and 14 denote arms attached to the gears 8 and 10, for example, one of which is a fixed arm. The transmission belt 6 may be provided separately from the variable elastic ring 4 and attached to the inner periphery thereof. The transmission belt 6 may be a toothed belt, and the inner periphery of the variable elastic ring 4 may be processed into a V-belt shape or the like. But it ’s okay. In the case of a V-belt shape, it may be driven by a pulley or the like instead of the gears 8 and 10.

  The inner circumference of the variable elastic ring 4, that is, the inner circumference of the transmission belt 6 is circular, the outer circumference thereof is elliptical, and the radial thickness of the ring 4 is made uneven along the circumferential direction. The wall thickness is minimum near the short axis S, and the wall thickness is maximum near the long axis T. Accordingly, the ring 4 includes a portion that gradually decreases from a portion with high rigidity to a small portion and a portion that gradually increases from a portion with low rigidity to a large portion along the circumferential direction. The rotation angle from the state in which the long axis T is in contact with the gears 8 and 10 is θ, and the thickness of the ring 4 in the depth direction, that is, the direction orthogonal to the axes S and T is constant. In the embodiment, the rigidity of the ring 4 is changed along the circumferential direction by controlling the wall thickness, but the material of the ring 4 is changed along the circumferential direction, a highly rigid member is laminated on the outer periphery of the ring 4, or The rigidity may be changed along the circumferential direction by performing a surface treatment on the outer periphery of the ring 4. Furthermore, the outer peripheral shape of the ring 4 is not limited to the ellipse of the embodiment, and may be appropriately designed by a genetic algorithm or the like so as to obtain a necessary elastic modulus distribution.

  FIG. 2 shows an example of measured values of the rotation angle θ and the elastic modulus k when the ring 4 is regarded as a spring connecting the gears 8 and 10, where the elastic modulus is shown in arbitrary units, This is a result when the ring 4 is designed so that a desired elastic modulus distribution can be obtained by a genetic algorithm. Although not shown in the drawing, the ring 4 is a linear elastic body, and the spring force is proportional to the displacement from the natural length.

  The variable elastic element 2 in FIG. 1 functions as a tension spring, but the variable elastic element 22 in FIG. 3 is also configured to function as a push spring. Reference numerals 23 to 26 denote gears, which are coupled by a pantograph 27 and transmit the driving force of the driving motor 29 to the four gears 23 to 26 by the transmission belt 28. In this example, since the four gears 23 to 26 are all drive gears and the transmission belt 6 is driven by the four drive gears, the transmission belt 6 is driven by one drive gear and one driven gear as shown in FIG. Compared to the case, the ring 4 can be rotated reliably and smoothly. Further, in addition to the gears 23 and 24 corresponding to the gears 8 and 10 in FIG. 1, a pair of gears 25 and 26 are provided in a direction orthogonal thereto. Therefore, when the distance between the gears 23 and 24 is shortened, the distance between the gears 25 and 26 is widened and the ring 4 is pushed. Conversely, when the distance between the gears 25 and 26 is shortened, the distance between the gears 23 and 24 is increased. Since the ring 4 is pushed out, the ring 4 can be operated as a push spring or a pull spring. Further, in the ring 4, if the rigidity is different between the portion in contact with the gears 23, 24 and the portion in contact with the gears 25, 26, the elasticity of the ring 4 is different depending on whether it is operated as a push spring or a pull spring. The rate can be easily varied.

  The variable elastic element 32 of FIG. 4 is configured such that the worm gear 34 is driven by a drive motor 35 and the gear 23 is rotated. Instead of the worm gear 34, power may be transmitted in a direction perpendicular to or not parallel to the axis of the motor 35 with a pair of bevel gears or the like. In the variable elastic element 32 of FIG. It is particularly compact because it can be accommodated in a space.

  FIG. 5 shows a joint 40 using the variable elastic element of the embodiment, and a pair of variable elastic elements 2 and 2 ′ are arranged on the left and right of the joint body 42. The variable elastic elements 2, 2 'are stretched by a pretension displacement d from their natural length L0 so that the tension is reversed, that is, pretension is applied so as to antagonize, 44 is a joint axis, 45 is The control unit drives the drive motors of the variable elastic elements 2, 2 '. The control unit 45 can rotate the ring of the variable elastic elements 2 and 2 ′ by a predetermined amount by appropriately driving the drive motor, and the ring can be moved from the portion having high rigidity along the circumferential direction. Since it has a part that gradually decreases to a small part and a part that gradually increases from a small part to a large part, the ring can be rotated to an appropriate position with respect to a load applied from the outside. it can.

  Here, when the elastic moduli of the variable elastic elements 2 and 2 ′ are equal, the joint body 42 takes a symmetrical posture, and from this state, the control unit 45 determines the elastic moduli of the left and right variable elastic elements 2 and 2 ′. When controlled antisymmetrically, the joint body 42 rotates, and the rotation angle θ is given by θ = x / R where R is the joint radius and x is the displacement of the variable elastic elements 2 and 2 ′. Further, when the elastic moduli of the left and right variable elastic elements 2, 2 'are controlled in the opposite directions from the balanced state to the left and right, the displacement x is proportional to the pre-tension displacement d. The displacement d may be determined according to the above.

  The condition that the joint body 42 is neutral is that the elastic moduli 2 and 2 'on the left and right are equal, and the joint body 42 can be rotated by making the elastic moduli unbalanced. The rotation angle θ is proportional to the difference in elastic modulus. Further, the rigidity of the joint 40 at each rotation angle θ is determined by the sum of the elastic moduli of the left and right variable elastic elements 2 and 2 ′. Therefore, by independently controlling the elastic moduli of the left and right variable elastic elements 2, 2 ', the orientation and rigidity of the joint 40 can be controlled independently.

  The joint 40 imitates the joint of an animal. For example, the joint 40 is a robot having an arm close to a human skeleton. When each arm is connected by the joint 40, it can be a walking robot. In addition, this robot can grasp a thing like a human and work in a desired posture. When arms are arranged to resemble reptile lizards or snake skeletons and these arms are connected by joints 40, a meandering robot can be obtained. Such a robot, for example, can change the width of the meandering according to the width of the passage and can work in a narrow space in the hole.

  FIG. 6 shows an application to the transport carriage 50, in which 52 is a carriage, and the loading platform 54 is connected to the carriage 52 with the variable elastic element 22 as a vertical suspension. Reference numeral 55 denotes a guide shaft, and 56 denotes a guide portion, which prevents the loading platform 54 from being displaced with respect to the carriage 52 in a horizontal plane. 58 is a transfer device, and 59 is a transported article. Instead of the transport carriage 50, an automobile, a train, or the like may be used.

  The transport carriage 50 vibrates in the vertical direction in the traveling direction, and it is necessary to protect the transported article 59 from this vibration. If vibration in the horizontal plane is also a problem, the loading platform 54 may be connected to the carriage 52 by the variable elastic element 22 in the horizontal direction. The control unit 57 reduces the elastic modulus of the variable elastic element 22 while the transport carriage 50 is traveling, and prevents vibration during traveling from being transmitted to the loading platform 54. Further, when the transport carriage 50 is stopped and the transported article 59 is transferred by the transfer device 58, even if the elastic modulus is increased by the variable elastic element 22 by the control unit 57 and the transfer device 58 is operated, The loading platform 54 is prevented from tilting left and right in the traveling direction. Further, in order to further reduce the vibration during traveling, a means for detecting the vibration state of the carriage 52 is provided to detect the vibration state such as the frequency and amplitude, and the elasticity of the variable elastic element 22 is dynamically changed in accordance with this. The rate may be controlled. In the embodiment of FIG. 6, it is possible to reduce vibration during traveling and to fix the posture of the loading platform 54 during transfer.

  FIG. 7 shows an example in which the variable elastic element 22 of the embodiment is used as the dynamic vibration absorber 72 of the stacker crane 60. 62 is a lower carriage, 63 and 64 are upper and lower traveling rails, and 65 is an upper carriage. Reference numeral 66 denotes a mast between the carriages 62 and 65. A lift 69 is moved up and down along the mast 66, 67 is a lift motor, 68 is a travel motor, and 70 is an upper wheel. Reference numeral 72 denotes the dynamic vibration absorber described above, and a vibrator 73 is attached via the variable elastic element 22, and the control unit 74 controls the elastic modulus of the variable elastic element 22.

In the stacker crane 60, the mast 66 vibrates when stopped from traveling, and the transfer article 75 on the lifting platform 69 cannot be transferred until the vibration is reduced. For this reason, the time until the vibration is settled after the traveling stops is a dead time. The vibration frequency of the mast 66 at this time varies depending on the position of the lift 69 and also varies depending on the presence / absence of the conveyed article 75. Therefore, the control unit 74 controls the elastic modulus of the variable elastic element 22 in consideration of the height of the lift 69, more preferably the presence or absence of the transported article 75, so that the vibration of the mast 66 can be efficiently absorbed. To. Instead of the stacker crane 60, the dynamic vibration absorber 72 may be used for other transport devices, machine tools, precision machines, precision instruments, vehicles, and the like.

Principal part plan view of the variable elastic element of the embodiment 1 is a characteristic diagram showing the relationship between the rotation angle and the elastic modulus of the variable elastic element of FIG. The principal part top view of the variable elastic element of 2nd Example The principal part top view of the variable elastic element of a modification FIG. 4 is a diagram schematically showing a joint using the variable elastic element of the embodiment, in which a) shows a state in which the elastic moduli of the left and right variable elastic elements are balanced with a pretension applied, and b) A state where the elastic moduli of the left and right variable elastic elements are unbalanced from the state of a) is shown. Side view with a partially cut-out portion of a transport carriage using the variable elastic element of the embodiment Side view of a stacker crane using the variable elastic element of the embodiment

Explanation of symbols

2 Variable elastic element 4 Variable elastic ring 6 Transmission belt 8, 10 Gear 12 Drive motor 13, 14 Arm 22, 32 Variable elastic element 23-26 Gear 27 Pantograph 28 Toothed belt 29 Drive motor 34 Worm gear 35 Drive motor 40 Joint 42 Joint body 44 Joint shaft 45 Control unit 50 Conveying carriage 52 Cart 54 Loading platform 55 Guide shaft 56 Guide unit 57 Control unit 58 Transfer device 59 Conveying article 60 Stacker crane 62 Lower cart 63, 64 Traveling rail 65 Upper cart 66 Mast 67 Elevating Motor 68 Traveling motor 69 Lifting table 70 Upper wheel 72 Dynamic vibration absorber 73 Vibrator 74 Control unit 75 Conveyed article

S short axis T long axis θ rotation angle x displacement L0 natural length
d Pre-tension displacement R Joint radius k Elastic modulus

Claims (7)

A variable elastic element provided with a ring-shaped elastic body whose rigidity changes along the circumferential direction and a rotating means for rotating the elastic body. 2. The belt according to claim 1, wherein a belt is disposed on an inner periphery of the ring-shaped elastic body, and a transmission vehicle is disposed in the ring as the rotating means to operate the belt. Variable elastic element. A ring-shaped elastic body having at least a portion that gradually decreases from a portion with high rigidity to a small portion along a circumferential direction, and a portion that gradually increases from a portion with low rigidity to a large portion;
Rotation means for rotating the elastic body;
A variable elastic element comprising: control means for changing the position of the elastic body so as to correspond to a load applied from the outside by controlling the rotation of the rotation means. 4. The variable elastic element according to claim 2, wherein four rotation vehicles are provided as the rotating means, and these are connected by a transmission belt and coupled by a pantograph. The joint which arrange | positioned the variable elastic element in any one of Claims 1-4 so that it might antagonize in the state which added the pretension to the both sides of the joint main body. A control means for controlling the rotating means of the variable elastic element so that the variable elastic element according to any one of claims 1 to 4 is used for a suspension, the rigidity is reduced during traveling, and the rigidity is increased when stopped. Vehicle provided. A motion is provided, wherein a vibrator is attached to the variable elastic element according to any one of claims 1 to 4, and a control means is provided for controlling the rotating means of the variable elastic element according to the frequency of the vibration control target. Vibration absorber.

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