JP2011256911A - Regulating unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regulating unit with a simple structure that can be easily attached to a wire and can regulate the rigidity of the wire.SOLUTION: In the regulating unit 10A, a bending part W1 of the wire W having passed through an insert hole 31 of a second supporting member 12 and an air-core area G2 of a compression coil spring 13 is locked with a locking part 23 of a first supporting member 11. With such a simple structure having a small number of parts, the regulating unit can regulate the rigidity of the wire and can be easily attached to the wire W while the wire W is being stretched.

Description

  The present invention relates to an adjustment unit.

  Conventionally, in various robots such as humanoid robots and pet robots, a drive motor is arranged in the apparatus main body, a wire interlocking with the drive motor is drawn around a pivotally connected joint unit, and the wire is pulled by the drive motor. Thus, a robot including a tendon drive mechanism that drives the joint unit is considered (for example, see Patent Document 1). Since such a tendon drive mechanism section can separate the drive motor from the joint unit and install the drive motor at a desired position, the joint unit itself can be reduced in size and weight. Have.

  In such a tendon drive mechanism, the joint unit can be smoothly driven by adjusting the rigidity of the wire. Therefore, the drive motor is controlled by software to adjust the rigidity, or it is provided on the wire. It is considered that the rigidity adjustment is performed by the rigidity adjustment unit (see, for example, Non-Patent Document 1 and Non-Patent Document 2).

JP 7-96485 A

Hogan. N. Impedance control: An approach to manipulator, part1-3. Trans. ASME, Journal of Dynamic of Dynamic Systems, Measurement and Control, Vol. 107, pp. 1-24, 1985. Kazuhito Hyodo, Hiroaki Kobayashi. Research on tendon control wrist mechanism with nonlinear spring element. Journal of the Robotics Society of Japan, Vol. 11, No. 8, pp. 1244-1251, 1993.

  However, in the tendon drive mechanism that adjusts the rigidity by software control of the drive motor based on the tension sensor, there is a problem that the configuration becomes complicated by the provision of the sensor and the controller, and there is a limit to the responsiveness due to sensor feedback In addition, there are problems such as failure to function at all due to sensor failure.

  On the other hand, in the conventional stiffness adjusting unit in Non-Patent Document 2, the stiffness of the wire can be mechanically adjusted using an elastic member, and a higher-speed response than that at the time of stiffness adjustment by sensor feedback can be realized. However, when attaching such a rigidity adjustment unit to a wire, it is necessary to pass the tip of the wire through the rigidity adjustment unit after all the wires have been unwound. There is a problem that the installation work is complicated.

  In particular, when the rigidity adjustment unit is incorporated later into the existing tendon drive mechanism, it is not assumed that the tendon drive mechanism disassembles the wire and other peripheral parts, so that the disassembly work takes time. There was a problem. In addition, since such disassembly work may cause a failure of the tendon drive mechanism, the rigidity adjustment unit can be easily attached to the wire without disassembling the wire and other peripheral parts during attachment work. It is desirable that it can be attached to.

  Accordingly, the present invention has been made in consideration of the above points, and an object thereof is to provide an adjustment unit that can adjust the rigidity of the wire with a simple configuration and can be easily attached to the wire.

  In order to solve such a problem, according to a first aspect of the present invention, in the adjustment unit for adjusting the tension of the stretched wire, the first support member provided with the shaft portion having the notch portion, and the first A second support member disposed opposite to the support member and having an insertion hole into which the shaft portion can be inserted; and the shaft portion is disposed in an air core region of a spiral winding portion, and the first support member And an elastic member that urges the second support member in a direction away from the wire, and the wire is bent to form a curved portion, and the insertion hole of the second support member and the elastic member The curved portion is locked to the cutout portion of the first support member, and when the wire is pulled with a predetermined force, the first support member Move in a direction approaching the second support member against the biasing force The one in which the features.

  According to a second aspect of the present invention, at the other end of the shaft portion, the curved portion of the wire inserted from the notch portion is locked to the locking portion and locked to the locking portion. A recess for positioning the wire is provided.

  According to a third aspect of the present invention, the first support member has a head that is formed in a flange-like shape at one end of the shaft portion and has an opening in the cutout portion. One end of the member is positioned between the side wall portion of the head and the shaft portion, and the other end of the elastic member is positioned at a step portion formed around the insertion hole in the second support member. It is characterized by that.

  According to a fourth aspect of the present invention, a guide groove for guiding the stretched wire to the insertion hole is formed in the second support member.

  According to a fifth aspect of the present invention, the wire is stretched between a drive motor provided at a predetermined position and a predetermined movable part, and the movable part is moved according to the drive of the drive motor. It is used for adjusting the rigidity of the wire to be driven.

  According to the first aspect of the present invention, the rigidity of the wire can be adjusted with a simple configuration with a small number of parts, and the wire can be easily attached to the wire while being stretched.

It is the schematic which shows a structure when the rigidity adjustment unit of this invention is attached to an arm part unit. It is the schematic which shows the whole structure of an adjustment unit, and a structure when an adjustment unit is decomposed | disassembled. It is sectional drawing which shows the longitudinal cross-section structure of a 2nd supporting member. It is the schematic which shows the procedure which attaches an adjustment unit to a wire. It is the schematic which shows the routing route of the wire at the time of attaching the adjustment unit to a wire. It is the schematic which shows the mode of a change inside an adjustment unit at the time of applying tension | tensile_strength to the wire which attached the adjustment unit. It is the schematic which shows the detailed structure of the variable path | route where a wire is routed. It is a graph which shows the relationship between tension | tensile_strength and the movement amount of a wire. It is a graph which shows the relationship between tension | tensile_strength and rigidity. It is the schematic which shows the structure of the 1st supporting member by other embodiment.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  In FIG. 1, reference numeral 1 denotes an arm unit of a robot. The arm unit 1 is composed of three blocks, an upper arm block 2, a forearm block 3, and a hand block 4, and the upper end of the upper arm block 2 is It is connected to a trunk unit (not shown) via a shoulder joint mechanism (not shown).

  Further, the arm unit 1 has a joint unit 5 in which the lower end portion of the upper arm block 2 and the upper end portion of the forearm block 3 are rotatably connected, and the upper arm block 2 is connected by a tendon drive mechanism described later. On the other hand, the forearm block 3 can be pivotably moved about the joint unit 5 as a pivot axis.

  Here, the tendon drive mechanism has a drive motor (not shown) installed in the trunk unit and a wire W that pulls the forearm block 3 in conjunction with the drive motor. In FIG. 1, for convenience of explanation, only the tendon drive mechanism that drives the forearm block 3 is noted, and only the wire W of the tendon drive mechanism is shown.

  In practice, this wire W passes through the upper arm block 2 from, for example, a drive motor installed in the body unit, is exposed to the outside from a predetermined location of the upper arm block 2 and straddles the joint unit 5, and forearm block 3 is fixed at a predetermined position. The wire W is pulled in conjunction with the drive motor, and the forearm block 3 can be rotated about the joint unit 5 as a rotation axis by this tensile force.

  In the case of this embodiment, the wire W for rotating the forearm block 3 is provided with the adjustment unit 10 according to the present invention, and the adjustment unit 10 adjusts the rigidity of the wire W. In addition, the adjustment unit 10 is added to a wire (not shown) attached to the elbow, the rigidity is adjusted, and the rigidity of the joint unit is adjusted by antagonizing the wire W. In the above-described embodiment, the case where the adjustment unit 10 is provided only on the wire W that rotates the forearm block 3 with the drive motor has been described, but the present invention is not limited to this, and the upper arm block is not limited thereto. You may make it provide the adjustment unit 10 in various other wires, such as a wire which rotates 2 with a drive motor.

  In practice, as shown in FIGS. 2A and 2B, the adjustment unit 10 includes a first support member 11, a second support member 12 disposed to face the first support member 11, A compression coil spring 13 is disposed between the first support member 11 and the second support member 12.

  The first support member 11 is made of, for example, a metal material, and has a bottomed cylindrical head 15 having a predetermined thickness and a radius smaller than the radius of the head 15 as shown in FIG. The shaft portion 16 is erected on the head portion 15 so that the center portion of the head portion 15 and the center axis of the shaft portion 16 coincide with each other. Actually, the head portion 15 has a bottom surface portion 17 and a side wall portion 18 erected around the bottom surface portion 17, and an opening 19 cut out in a straight line forms the center portion of the head portion 15. It is formed from the bottom surface portion 17 to the side wall portion 18 so as to pass therethrough.

  Further, the head portion 15 is provided with a side wall portion 18 at a predetermined distance from the shaft portion 16, and an annular space G1 is formed between the shaft portion 16 and the side wall portion 18, and the space G1 One end of the compression coil spring 13 can be fitted and positioned.

  The shaft portion 16 has a configuration in which one end is integrally formed with the bottom surface portion 17 of the head portion 15 and a notch portion 21 is formed in the outer peripheral portion 22a along the axial direction. Actually, the notch portion 21 is formed in the outer peripheral portion 22a so as to communicate with the opening 19 of the head portion 15 and penetrate the shaft portion 16 along the axial direction, and has a width dimension through which the wire W can be inserted. Selected. At the other end of the shaft portion 16, a circular end surface portion 22b is formed, and a locking portion 23 with which the wire W is locked is formed on the end surface portion 22b.

  In addition, in the case of this embodiment, an inclined surface 22c is formed between the end surface portion 22b of the shaft portion 16 and the outer peripheral portion 22a, and the inclined surface 22c is cut along the notch portion 21. A recess 25 that is recessed and recessed in the inclined surface 22c is formed. As a result, when the wire W is locked, the locking portion 23 positions the wire W in the recess 25 and is pulled out from the end surface portion 22b side without exposing the wire W from the outer peripheral portion 22a. Has been made.

  On the other hand, the compression coil spring 13 is made of, for example, a metal material, and has a winding part 27 in which a strip-like member is spirally wound, and the shaft of the first support member 12 is placed in the air core region G2 of the winding part 27. The part 16 is inserted, and the winding part 27 can be arranged along the outer peripheral part 22a of the shaft part 16.

  In the case of this embodiment, the compression coil spring 13 has a quadrilateral cross section and the winding part 27 is formed of a band-shaped metal member. Therefore, when the winding part 27 is formed of a metal member having a circular cross section, In comparison, the contact surface between the first support member 11 and the second support member 12 can be increased. In particular, in the case of this embodiment, the compression coil spring 13 has a winding portion 27 made of a metal member having a quadrilateral cross section with a short axial direction and a long radial direction. Can be made shorter and more compact.

  The second support member 12 is made of, for example, a metal part material, has a main body part 30 having a substantially cylindrical shape and an inclined surface 30a formed to round corners, and the main body part 30 has a central axis as a center. A cylindrical insertion hole 31 is formed. In the case of this embodiment, the insertion hole 31 is selected such that its radius is larger than the radius of the shaft portion 16 of the first support member 11, and when the shaft portion 16 is inserted into the insertion hole 31, The shaft portion 16 is formed so as not to contact the inner peripheral surface of the insertion hole 31.

  The main body 30 is formed with guide grooves 33a and 33b for positioning the wire W so as to face the side wall 32, and the guide grooves 33a and 33b form the insertion hole 31 and the outside from the side of the side wall 32. It is made to be able to communicate with. In practice, the guide grooves 33a and 33b are formed by notching the side wall 32, and as shown in FIG. 3, the end portions of the guide grooves 33a and 33b are swelled in a curved shape. 34b is provided.

  Thus, the guide grooves 33a and 33b are configured such that when the wire W is inserted, the wire W can smoothly slide on the sliding contact surfaces 34a and 34b. In addition, a stepped portion 36 is formed around the insertion hole 31 on the inner peripheral surface of the main body, and the other end of the compression coil spring 13 is in contact with the flat portion of the stepped portion 36 to be positioned. Has been made to get.

  The adjustment unit 10 having such a configuration is attached to the stretched wire W as shown in FIG. 4A by the following procedure. First, as shown in FIG. 4B, the wire W is accommodated in the guide grooves 33a and 33b of the second support member 12, and the wire W is loosened and bent as shown in FIG. 4C. Thus, an Ω-shaped curved portion W1 is formed, the curved portion W1 is inserted into the insertion hole 31 of the second support member 12, and the curved portion W1 of the wire W is exposed from the other end of the main body portion 30.

  Next, as shown in FIG. 4D, the bending portion W1 of the wire W is inserted through the air core region G2 of the compression coil spring 13. 4 (E), (F), (G) and (H), the curved portion W1 of the wire W exposed from one end of the compression coil spring 13 is connected to the head 15 of the first support member 11. By inserting the wire W into the cutout portion 21 through the opening 19 and pulling the wire W, the curved portion W1 of the wire W is locked to the locking portion 23 at the terminal portion of the cutout portion 21.

  Thus, as shown in FIG. 5, the adjustment unit 10 compresses after the bending portion W1 formed by loosening the wire W is inserted from one end of the insertion hole 31 in the second support member 12. After passing through the air core region G2 of the coil spring 13 and being inserted into the cutout portion 21 from the opening 19 of the head portion 15 in the first support member 11, the wire W is tensioned again as shown in FIG. By bending, the bending portion W1 is locked to the locking portion 23.

  Thus, when the adjusting unit 10 is attached to the stretched wire W, the wire W locked to the locking portion 23 of the first support member 11 is supported by the urging force of the compression coil spring 13 for the second support. Pulling is performed in the direction Z1 away from the member 12.

  As a result, as shown in FIG. 7, the adjustment unit 10 has the first support member 11 through the locking portion 23 of the first support member 11 from the sliding contact surface vertex S1 of the one guide groove 33a. A wire that is routed through a wire W through a path to the slidable contact surface vertex S2 of the other guide groove 33b in the second support member 12 (hereinafter referred to as a variable path) and is stretched linearly. Compared with W, it is possible to lengthen the route of the wire W by the amount bent by the variable route, and to maintain the state where the wire W is stretched.

  In addition, when the wire W stretched from this state is pulled, the adjustment unit 10 causes the first support member 11 to act on the urging force of the compression coil spring 13 by the wire W as shown in FIG. On the other hand, it moves in the direction Z2 approaching the second support member 12, and the variable path through which the wire W passes can be changed linearly while the wire W is stretched. As described above, the adjustment unit 10 can adjust the rigidity of the wire W by the urging force of the compression coil spring 13 when a tension is applied to the wire W.

  Next, in order to know the amount of movement of the wire W that is pulled out from the adjustment unit 10 and the curve characteristics of the tension applied to the wire W, the following calculation was performed. Here, the compression coil spring 13 in the adjustment unit 10 has a contraction t, the spring coefficient of the compression coil spring 13 is k, the tension on the wire is T, and the compression coil spring 13 is connected to the compression coil spring 13 via the guide grooves 33a and 33b. If the force applied to each is F, the following relationship holds from the balance of forces.

  The distance from the center axis of the adjusting unit 10 to the sliding contact surface vertex S2 of the guide groove 33b is a, and the guide groove extends from the center of curvature of the sliding contact surface of the locking portion 23 when the compression coil spring 13 is in a natural length state. The distance from the sliding contact surface vertex S2 of 33b is b, the length of the variable path of the wires W stored in the adjustment unit 10 is h, and the sliding contact surfaces 34a, 34b of the guide grooves 33a, 33b The radius of curvature of the slidable contact surface of the stop portion 23 is r, the inclination angle formed between the horizontal direction and the wire W passing between the locking portion 23 and the guide grooves 33a and 33b is θ, and the wire drawn from the adjustment unit 10 is pulled out. If the amount of movement (elongation) that moves is x, the following relationship can be shown.

  Then, from these numbers (1) to (5), the following numbers (6) and (7) were obtained with respect to the tension T and the movement amount x that the wire W moved from the adjustment unit 10 moves.

  From these numbers (6) and (7), the theoretical curve of the tension T of the wire W and the amount of movement x when the spring coefficient k is determined to a predetermined value can be obtained, and the rigidity E = dT / dx You can also ask for.

  Here, FIG. 8 is a graph showing the relationship between the tension T of the wire W and the moving amount x of the wire W that is pulled out from the adjustment unit 10 and is about 20 mm at maximum when the wire W is pulled. This shows that the wire W is pulled out from the adjustment unit 10. FIG. 9 shows the relationship between the tension T and the rigidity E of the wire W. FIG. 8 and FIG. 9 are theoretical values and show two types of graphs when the spring coefficient k is 1.0 kgf / mm and 0.1 kgf / mm. At this time, the rigidity E increases to the same value as that of the wire W and reaches the limit. FIG. 9 shows the change, and it can be seen that the rigidity E becomes a maximum at a constant tension T. FIG. However, since the graph shown in FIG. 9 is a theoretical value, it diverges to the maximum, but in reality, the rigidity of the wire W itself is reached and becomes a limit.

  As shown in FIG. 8, the larger the spring coefficient k, the larger the tension T required until the movement amount x of the wire W in the adjustment unit 10 is maximized. Therefore, in FIG. It can be seen that the curve with the rigidity E becomes gentler and that the rigidity can be adjusted more finely than when the spring coefficient k is low.

  In the above configuration, in the adjustment unit 10, the curved portion W1 formed by loosening the wire W is passed through the insertion hole 31 in the second support member 12 and the air core region G2 of the compression coil spring 13. Then, the first support member 11 is inserted into the cutout portion 21 from the opening 19 of the head portion 15 and is locked to the locking portion 23 of the first support member 11.

  As a result, in the adjustment unit 10, the first support member 11 is positioned in the direction Z1 away from the second support member 12 by the urging force of the compression coil spring, and the wire W is pulled by the locking portion 23. Can maintain a stretched state.

  At this time, in the adjustment unit 10, the wire W is routed in a state of being bent in an Ω shape via the variable path, so that the variable path is equivalent to the wire W stretched linearly. The route of the wire W can be lengthened.

  In the adjustment unit 10, when the stretched wire W is pulled, the first support member 11 approaches the second support member 12 against the biasing force of the compression coil spring 13 by the wire W. The variable path through which the wire W passes is shortened while moving in the direction Z2 and the wire W is stretched, and the wire W can be pulled out.

  In this manner, in the adjustment unit 10, when tension is applied to the wire W, the biasing force of the compression coil spring 13 is generated according to the tension applied to the wire W, so that the rigidity of the wire W can be adjusted.

  In the adjustment unit 10, the curved portion W 1 of the wire W that has passed through the insertion hole 31 of the second support member 12 and the air core region G 2 of the compression coil spring 13 is connected to the first support member 11. Since it only needs to be locked to the stop portion 23, it can be attached simply by loosening the wire W. Thus, the conventional work of disassembling the wire W is not required, and the wire W remains stretched. Easy to install.

  Further, in this adjustment unit 10, when the stretched wire W is pulled, the compression coil spring 13 is compressed, and the rigidity of the wire is adjusted by the urging force generated by this compression. Since a strong urging force can be generated, it is possible to cope with a large tension generated in the wire W, and a smooth rigidity adjustment can be performed.

  In addition, in the adjustment unit 10, the shaft portion 16 of the first support member 11 is inserted in a non-contact state with the insertion hole 31 of the second support member 12, and the first support member 11 and the second support member 11 are inserted. Since the support member 12 is connected only by the compression coil spring 13, the friction can be reduced as much as the first support member 11 and the second support member 12 are not in contact with each other, and smooth rigidity adjustment can be performed. It can be carried out.

  In addition, in this adjustment unit 10, the longitudinal direction can be arranged perpendicular to the wire W, and the corner is relatively rounded with few corners, so that the wire in a limited space can be used. Can be attached.

According to the above configuration, in the adjustment unit 10, the curved portion W1 of the wire W that has passed through the insertion hole 31 of the second support member 12 and the air core region G2 of the compression coil spring 13 is used as the first support. By engaging with the locking portion 23 of the member 11, the rigidity of the wire can be adjusted with a simple configuration with a small number of parts, and the wire W is stretched with respect to the wire W while being stretched. It should be noted that the present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, as shown in FIG. 10 in which the same reference numerals are assigned to the corresponding portions of the first support member 11 shown in FIG. 2B, the first support member 41 according to another embodiment is formed of the shaft portion. Unlike the first support member 11 shown in FIG. 2 (B), the recess 42 formed at the other end is formed so as to be cut out not only to the inclined surface 22c but also to the end surface portion 22b. Yes. In this case, since the depth of the recess can be increased, even if the wire W is thick, the wire W is prevented from protruding from the outer peripheral portion 22a of the shaft portion 16, and the wire W is exposed from the end surface portion 22b side. Can do.

  In the above-described embodiment, the wire W is stretched between the forearm block 3 that is a movable part and the drive motor provided at a predetermined position, and the wire W is pulled according to the drive of the drive motor. The case where the adjustment unit 10 of the present invention is applied to the robot that drives the forearm block 3 by the tensile force of the wire W has been described. However, the present invention is not limited to this, and for example, a predetermined part in various situations. The adjustment unit 10 may be applied to a wire stretched between them to adjust the rigidity of the wire.

  In the above-described embodiment, the case where the compression coil spring 13 is applied as the elastic member has been described. However, the present invention is not limited thereto, and is formed of an elastic material such as rubber, and has a cylindrical shape and an air core region. Various other elastic members such as an elastic member may be applied.

3 Forearm block (movable part)
10 Adjustment unit
11 First support member
12 Second support member
13 Elastic member (compression coil spring)
16 Shaft
21 Notch
27 Winding part

Claims (5)

In the adjustment unit that adjusts the tension of the stretched wire,
A first support member provided with a shaft portion having a notch;
A second support member disposed opposite to the first support member and having an insertion hole into which the shaft portion can be inserted;
The shaft portion is disposed in the air core region of the spirally wound portion, and includes an elastic member that biases the first support member and the second support member away from each other,
In a state in which the wire is bent to form a curved portion, the wire passes through the insertion hole of the second support member and the air core region of the elastic member, and enters the notch portion of the first support member. The bend is locked,
The adjustment unit, wherein when the wire is pulled with a predetermined force, the first support member moves in a direction approaching the second support member against a biasing force of the elastic member. At the other end of the shaft portion, a curved portion of the wire inserted from the notch portion is locked to the locking portion, and a recess for positioning the wire locked to the locking portion is provided. The adjustment unit according to claim 1, wherein: The first support member has a head that is formed to protrude from one end of the shaft portion in a collar shape, and an opening of the cutout portion is formed.
One end of the elastic member is positioned between the side wall portion of the head and the shaft portion,
The adjustment unit according to claim 1, wherein the other end of the elastic member is positioned at a stepped portion formed around the insertion hole in the second support member. The second support member includes
The adjustment unit according to any one of claims 1 to 3, wherein a guide groove that guides the stretched wire to the insertion hole is formed. The wire is stretched between a drive motor provided at a predetermined position and a predetermined movable part,
The adjustment unit according to any one of claims 1 to 4, wherein the adjustment unit is used to adjust rigidity of the wire that drives the movable portion in accordance with driving of the drive motor.

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