JP2012202477A - Reciprocating driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for reciprocating and driving a member to be driven, increasing a force for reciprocating and driving the member to be driven with simple configuration and reducing the axial dimension of the member to be driven, in the device.SOLUTION: A piston device 10 includes a motor 20 having a drive shaft 22, and a drive roller 23 that has an outer peripheral surface coaxial with the drive shaft 22 and that is rotated integrally with the drive shaft 22. The piston device 10 also includes a coil spring 50 supported to be rotatable around the axis of a coil and to be reciprocated in a direction of the axis. The coil of the coil spring 50 spirally extends while forming a gap greater than the outer diameter of the tip part of the drive roller 23. The drive roller 23 is inserted in the gap of the coil, and the outer peripheral surface of the drive roller 23 abuts on the wire 50a of the coil.

Description

  The present invention relates to an apparatus for reciprocating a driven member.

  Conventionally, as this type of device, there is a device that converts the rotational motion of a rotational drive source into a linear motion (see, for example, Patent Document 1). In the device described in Patent Document 1, a small-diameter compression coil spring is connected coaxially to the drive shaft of the motor, and the small-diameter compression coil spring is inserted into the large-diameter compression coil spring. A plurality of balls are provided between the small diameter compression coil spring and the large diameter compression coil spring so as to be in contact with the coil springs. When the small diameter compression coil spring is rotated by driving the motor, the large diameter compression coil spring is linearly moved in the axial direction of the small diameter compression coil spring.

Japanese Patent Laid-Open No. 2004-217725

  By the way, in the thing of patent document 1, since a small diameter compression coil spring rotates at the speed equal to the drive shaft of a motor, the rotational torque of a small diameter compression coil spring cannot be enlarged, and, as a result, a large diameter compression coil spring is used. The force for reciprocating drive cannot be increased. Here, it is conceivable to provide a speed reduction mechanism between the drive shaft of the motor and the small-diameter compression coil spring, but in that case, an increase in the size of the device and an increase in cost cannot be avoided.

  Moreover, in the thing of patent document 1, since the motor is provided on the extension of the axial direction of a small diameter compression coil spring, there exists a problem that the dimension of the axial direction of the small diameter compression coil spring in an apparatus becomes large.

  The present invention has been made in view of such circumstances, and a main object of the present invention is to increase the force for reciprocating the driven member with a simple configuration in the apparatus for reciprocating the driven member, and to increase the force to be driven in the apparatus. It is to reduce the dimension of the driving member in the axial direction.

  The present invention employs the following means in order to solve the above problems.

  1st invention is a reciprocating drive device, Comprising: The motor which has a drive shaft, The drive member which has an outer peripheral surface coaxial with the said drive shaft, and rotates integrally with the said drive shaft, The outer diameter of the said drive member A driven member that has a spiral portion extending spirally while forming a gap having a wider interval, and is supported so as to be rotatable about the axis of the spiral portion and reciprocally movable in the direction of the axis; The drive member is inserted into the gap of the spiral portion, and the outer peripheral surface of the drive member is in contact with the spiral portion.

  According to the above configuration, when the drive shaft of the motor rotates, the drive member having the outer peripheral surface coaxial with the drive shaft is rotated integrally with the drive shaft. Here, the spiral portion extends spirally while forming a gap having a wider interval than the outer diameter of the drive member. And a drive member is inserted in the clearance gap between spiral parts, and the outer peripheral surface of a drive member is in contact with the spiral part. For this reason, a motor is arrange | positioned not in the axial direction of a spiral part but radial direction, and the dimension of the axial direction of the to-be-driven member in a reciprocating drive device can be reduced.

  The driven member is supported so as to be rotatable about the axis of the spiral portion and to be reciprocable in the direction of the axis. For this reason, when the drive member is rotated with the rotation of the drive shaft of the motor and a frictional force acts on the spiral portion from the outer peripheral surface of the drive member, the spiral portion is sequentially sent out. Therefore, the driven member is moved in the direction of the axis while being rotated about the axis of the spiral portion. At this time, the rotation of the drive member (drive shaft) is decelerated at a reduction ratio according to the diameter of the drive member and the diameter of the spiral portion. Therefore, the rotational torque generated in the driven member can be increased more than the rotational torque of the motor, and the force for reciprocating the driven member can be increased with a simple configuration.

  Since the second invention is provided with a force applying means for applying a pressing force to the spiral portion and the outer peripheral surface of the drive member, the friction acting between the spiral portion and the outer peripheral surface of the drive member. The power can be increased. Therefore, slippage between the spiral portion and the outer peripheral surface of the drive member can be suppressed, and the rotational torque of the drive member can be efficiently transmitted to the spiral portion.

  Specifically, as in the third aspect of the invention, the force applying means includes a rear portion inserted into the gap of the spiral portion on the opposite side of the drive member across a single portion of the spiral portion, It is possible to employ a configuration including a force applying portion that applies force to the rear portion so that a single portion of the spiral portion is pressed against the outer peripheral surface of the driving member. According to such a configuration, the rear portion is inserted on the opposite side of the drive member across the single portion of the spiral portion in the gap of the spiral portion. Then, a force is applied to the rear portion by the applied portion, and a single portion of the spiral portion is pressed against the outer peripheral surface of the drive member. Therefore, the frictional force acting between the spiral portion and the outer peripheral surface of the drive member can be increased.

  Further, in the fourth invention, the rear portion has a cylindrical surface in contact with the spiral portion, and is supported by the force application portion so as to be rotatable about the axis of the cylindrical surface. Therefore, when the spiral portion is sequentially sent out by the driving member, the rear portion can be rotated, and the frictional resistance between the spiral portion and the rear portion can be reduced. As a result, the drive energy loss of the motor can be reduced.

  Further, specifically, as in the fifth invention, the force applying means biases the driven member so that the spiral portion is pressed against the outer peripheral surface of the driving member. It is possible to adopt a configuration in which the urging portion is supported so as to be integrally rotatable with the driven member. According to such a configuration, the driven member is urged by the urging portion, and a single spiral portion is pressed against the outer peripheral surface of the driving member. Therefore, the frictional force acting between the spiral portion and the outer peripheral surface of the drive member can be increased. Furthermore, since the urging portion is supported so as to rotate integrally with the driven member, it is possible to prevent the urging portion from being twisted when the driven member is rotated.

  According to a sixth aspect of the invention, there is provided a reciprocating member coupled to the driven member and supported so as to be capable of reciprocating in the direction of the axis of the spiral portion, and the reciprocating member is the axis of the spiral portion. The driven member is rotated by a predetermined amount of rotation while maintaining a state in which the first restricting portion that restricts movement in a direction from a predetermined position and the spiral portion and the outer peripheral surface of the driving member are in contact with each other. And a second restricting portion that restricts rotation more than the above.

  According to the above configuration, the reciprocating member is connected to the driven member, and the reciprocating member is supported so as to be reciprocable in the direction of the axis of the spiral portion. Then, the first restricting portion restricts the reciprocating member from moving in the axial direction of the spiral portion from a predetermined position.

  Here, when the movement of the reciprocating member is restricted by the first restricting portion while the driven member is rotatable, the driven member connected to the reciprocating member is restricted from moving in the axial direction. There is a risk that it will rotate in a locked state. In that case, the spiral portion moves relative to the drive member, and the spiral portion and the outer peripheral surface of the drive member may be separated. And in the state which the spiral part and the outer peripheral surface of the drive member left | separated, rotation of a drive member cannot be transmitted to a spiral part.

  In this regard, according to the above configuration, the second restricting portion restricts the driven member from rotating more than a predetermined amount of rotation while maintaining the state where the spiral portion and the outer peripheral surface of the driving member are in contact with each other. . For example, the rotation of the driven member is regulated by the second regulating unit before the movement of the reciprocating member is regulated by the first regulating unit. For this reason, even if it is a case provided with the 1st control part which controls that a reciprocating member moves from a predetermined position, it can control that a spiral part and the outer peripheral surface of a drive member leave, and drive The rotational torque can be stably transmitted from the member to the spiral portion.

  In a seventh aspect of the invention, the second restricting portion extends along the spiral portion in the direction of the axis of the spiral portion and is provided so as to be integrally rotatable with the driven member. The drive member and the second restricting portion are arranged so that the drive member and the second restricting portion come into contact with each other when the member rotates by the predetermined rotation amount.

  According to the above configuration, the second restricting portion extends along the spiral portion in the direction of the axis of the spiral portion, and is provided so as to be integrally rotatable with the driven member. Therefore, as the driven member is rotated, the second restricting portion is rotated integrally with the driven member. The driving member and the second restricting portion are arranged so that the driving member and the second restricting portion come into contact when the driven member rotates by the predetermined rotation amount. For this reason, when the driven member moves in the axial direction while rotating, and the driven member rotates by the predetermined rotation amount, the second restricting portion hits the driving member and the rotation of the driven member is restricted. Therefore, with a simple configuration, it is possible to restrict the driven member from rotating more than a predetermined amount of rotation while maintaining the state where the spiral portion and the outer peripheral surface of the driving member are in contact with each other.

  In an eighth aspect of the invention, a plurality of teeth are provided on the outer peripheral surface of the drive member, and a portion of the spiral portion that contacts the outer peripheral surface of the drive member is arranged with the teeth of the drive member. A plurality of meshing teeth are provided.

  According to the said structure, the tooth | gear provided in the outer peripheral surface of the drive member has meshed | engaged with the tooth | gear provided in the part which contact | connects the outer peripheral surface of a drive member in a helical part. For this reason, the rotational torque of the drive member can be efficiently transmitted to the spiral portion. As a result, the rotational torque generated in the driven member can be further increased, and the force for reciprocating the driven member can be further increased.

  In the ninth invention, since the axis of the spiral portion and the axis of the drive shaft are orthogonal to each other, the axis of the drive shaft, that is, the axis of the outer peripheral surface of the drive member, is relative to the circumferential direction of the spiral portion. It will be orthogonal. For this reason, the direction in which the rotational torque of the drive member is transmitted can be matched with the direction in which the spiral portion is sent out. Therefore, the rotational torque of the drive member can be efficiently transmitted to the spiral portion.

  In a tenth aspect of the invention, the spiral portion is formed by a coil spring. According to such a configuration, the spiral portion can be formed by an inexpensive coil spring, and when the force is applied from the driven member to the object, the elastic force of the coil spring is applied to the object. be able to. Therefore, the force for reciprocating the driven member can be increased while adopting a configuration in which an elastic force is applied from the driven member to the object.

The fragmentary sectional view which shows the piston apparatus of 1st Embodiment. The enlarged view which shows a drive roller, a support roller, and its periphery. The fragmentary sectional view which shows the modification of the piston apparatus of FIG. The enlarged view which shows the drive roller, the support roller, and the modification of the periphery. The enlarged view which shows the other modification of a drive roller and a support roller, and its periphery. The fragmentary sectional view which shows the other modification of the piston apparatus of FIG. The fragmentary sectional view which shows the hand apparatus of 2nd Embodiment. The fragmentary sectional view which looked at the holding mechanism from the top. The enlarged view which shows a drive roller and a rotation stop part, and its periphery. The fragmentary sectional view which shows the fully closed state of a holding | grip mechanism. The enlarged view which shows a drive roller, a rotation prevention pin, and its periphery. The front view which shows the modification of a reciprocating drive device.

(First embodiment)
The first embodiment will be described below with reference to the drawings. In the present embodiment, the present invention is embodied as a piston device that is applied to a belt conveyor or the like and stops a conveyed work by reciprocating driving of the piston.

  FIG. 1 is a partial cross-sectional view showing a piston device 10 of the present embodiment. As shown in the figure, the piston device 10 includes a body 11, a stepping motor 20, a cylinder 30, a piston 40, a coil spring 50, and the like. The vertical direction in FIG. 1 coincides with the vertical direction when the piston device 10 is installed, and the piston device 10 reciprocates the piston 40 in the vertical direction.

  The body 11 is formed in a cylindrical shape with a metal material or the like. In the body 11, an opening 12 is provided at a side near one end in the axial direction, and a cylinder 30 is attached to the other end in the axial direction. A stepping motor 20 (motor) is attached to the opening 12 via a bracket 21 having an opening 21a. The motor 20 has a drive shaft 22, and the motor 20 is attached to the body 11 so that the axis of the body 11 and the axis of the drive shaft 22 are perpendicular to each other. The drive shaft 22 is inserted from the outside to the inside of the body 11 through the opening 21 a of the bracket 21 and the opening 12 of the body 11. A driving roller 23 is attached to the tip of the driving shaft 22. The drive roller 23 (drive member) is formed in a columnar shape and rotates integrally with the drive shaft 22. The axis of the drive roller 23 coincides with the axis of the drive shaft 22. The drive roller 23 has an outer peripheral surface that is coaxial with the drive shaft 22.

  The cylinder 30 is formed in a cylindrical shape with a metal material or the like. The axis of the cylinder 30 coincides with the axis of the body 11. A cylindrical piston 40 is inserted into the cylinder 30. The piston 40 (reciprocating member) is supported by the slide bearing 31 so as to be able to reciprocate in the axial direction of the body 11. A flat surface portion 40 a is provided on the outer peripheral surface of the piston 40 so as to extend in the axial direction. That is, in the piston 40, the cross-sectional shape of the portion where the flat surface portion 40a is provided is a “D” shape. In the piston 40, a detent member 32 having a through hole having a cross-sectional shape of “D” is fitted to the outer periphery of the portion where the flat portion 40 a is provided. The anti-rotation member 32 is fixed to the upper end of the cylinder 30. Therefore, the piston 40 can reciprocate in the axial direction in a state where the rotation about the axis is restricted.

  A holding portion 51 of a coil spring 50 is fastened with a bolt 41 to the lower end portion of the piston 40 (the end portion on the side close to the motor 20) via a thrust bearing 33 and a radial bearing 34. The holding part 51 is formed in a disc shape, and a guide ring 52 is provided on the outer periphery thereof. The outer peripheral surface of the guide ring 52 can slide smoothly with the inner peripheral surface of the body 11. For this reason, the holding part 51 is supported by the piston 40 so as to be rotatable about the axis of the piston 40 via the guide ring 52. The holding portion 51 is guided by the guide ring 52 in the axial direction of the body 11 as the piston 40 reciprocates. At that time, the axial load acting between the piston 40 and the holding portion 51 is received by the thrust bearing 33. A magnet 53 for detecting the position of the holding unit 51 by a sensor or the like is provided on the outer periphery of the holding unit 51.

  The coil spring 50 is attached to the lower part of the holding part 51 (the part opposite to the piston 40). The upper end (one end) of the coil spring 50 (driven member) is fixed to the lower portion of the holding portion 51 by caulking by the holding portion 51. The axis of the coil spring 50 coincides with the axis of the body 11. For this reason, the coil spring 50 is supported via the holding portion 51 so as to be rotatable about the axis of the coil and to be able to reciprocate in the direction of the axis.

  The coil (spiral portion) of the coil spring 50 extends in a spiral manner while forming a gap having a larger interval than the outer diameter of the tip end portion of the drive roller 23. That is, the distance between the coil wire 50 a (single) and the wire 50 a (single) is larger than the outer diameter of the tip of the drive roller 23. And the front-end | tip part of the drive roller 23 is inserted in the clearance gap between the strand 50a of a coil, and the strand 50a. On the coil spring 50, the weight of the piston 40, the weight of the holding portion 51, the weight of the coil spring 50, and the like act downward.

  For this reason, the strand 50a of the coil spring 50 is in contact with the upper surface (outer peripheral surface) of the drive roller 23. That is, the coil spring 50 is supported by the drive roller 23. In other words, the tip of the drive roller 23 is inserted into the gap of the coil so that the outer peripheral surface of the drive roller 23 is in contact with the wire 50a of the coil spring 50. And the motor 20 is attached to the body 11 so that it may be in such a state. The axis of the drive shaft 22 of the motor 20 is perpendicular to the axis of the coil spring 50.

  Next, the structure which presses the strand 50a (single) of the coil spring 50 to the drive roller 23 is demonstrated. FIG. 2 is an enlarged view showing the driving roller and the supporting roller and the periphery thereof, and FIG. 2A is a cross-sectional view taken along line AA of FIG.

  As shown in the figure, the drive roller 23 is made of steel or the like, and includes a distal end portion 25, a cylindrical portion 24, and a flange portion 26 whose axes are aligned with each other. A cylindrical tip portion 25 is provided at one end of the cylindrical cylindrical portion 24, and a flange-like flange portion 26 is provided at the other end. The drive shaft 22 of the motor 20 is press-fitted inside the cylindrical portion 24 and the flange portion 26. The distal end portion 25 is provided with a constricted portion 25a, and the outer diameter of the constricted portion 25a becomes smaller as it approaches the middle of the distal end portion 25 in the axial direction. In the longitudinal section including the axis of the tip portion 25, the radius of curvature of the constricted portion 25 a is equal to the radius of curvature of the outer peripheral surface of the wire 50 a in the coil spring 50. For this reason, the outer peripheral surface of the constricted part 25a and the outer peripheral surface of the strand 50a are in line contact.

  A roller holder 60 is attached to the outer periphery of the drive roller 23. The roller holder 60 (forced portion) is formed in an elliptical plate shape, and two through holes are formed side by side in the major axis direction. Radial bearings 61 and 62 are attached to the inner circumferences of the two through holes, respectively. The drive roller 23 and the support roller 63 are inserted into the radial bearings 61 and 62, respectively. For this reason, the drive roller 23 and the support roller 63 are rotatably supported by the roller holder 60.

  The flange portion 26 of the driving roller 23 is in contact with the end face of the radial bearing 61, and the roller holder 60 is prevented from coming off in the direction of the flange portion 26. Disengagement of the roller holder 60 in the direction of the element wire 50a of the coil spring 50 is suppressed by engagement of the constricted portion 25a of the drive roller 23 with the element wire 50a.

  The support roller 63 (rear part) is formed in a columnar shape with steel or the like, and includes a columnar part 64 and a distal end part 65 whose axis lines coincide with each other. The distal end portion 65 is provided with a constricted portion 65 a, and the outer diameter of the constricted portion 65 a becomes smaller as it approaches the middle in the axial direction of the distal end portion 65. In the longitudinal section including the axis of the tip 65 (support roller 63), the radius of curvature of the constricted portion 65a is equal to the radius of curvature of the outer peripheral surface of the wire 50a in the coil spring 50. For this reason, the outer peripheral surface (cylindrical surface) of the narrow part 65a and the outer peripheral surface of the strand 50a are in line contact.

  Two grooves are provided on the outer periphery of the cylindrical portion 64 at a distance slightly wider than the thickness of the roller holder 60 (radial bearing 62), and a retaining ring 66 is fitted in each of the grooves. Retaining rings 66 are in contact with both end faces of the radial bearing 62, and the support roller 63 is prevented from coming off the roller holder 60 in the axial direction. The engagement of the constricted portion 65a of the support roller 63 with the wire 50a of the coil spring 50 also prevents the support roller 63 from coming off from the roller holder 60 in the axial direction.

  The diameter of the front end portion 65 of the support roller 63 is smaller than the diameter of the front end portion 25 of the drive roller 23. And the front-end | tip part 65 of the support roller 63 is inserted in the clearance gap between the strand 50a of a coil, and the strand 50a. That is, the support roller 63 is inserted into the gap between the coils on the opposite side of the drive roller 23 with the strand 50a (single) of the coil spring 50 interposed therebetween. The axis of the drive roller 23 and the axis of the support roller 63 are parallel, and the axis of the drive roller 23 and the axis of the support roller 63 are perpendicular to the axis of the strand 50a with which these rollers 23 and 63 are in contact. Yes.

  As shown in FIG. 5A, in the roller holder 60, a notch 67 is provided between the radial bearing 61 and the radial bearing 62. The notch 67 passes through the roller holder 60 in the thickness direction of the roller holder 60. The roller holder 60 is made of a metal material or the like having a relatively large elasticity, and generates an elastic force in a direction in which the width of the notch 67 is narrowed, that is, in a direction in which the radial bearings 61 and 62 are brought close to each other.

  Therefore, as shown in FIG. 5B, in the state where the element wire 50a of the coil spring 50 is sandwiched between the drive roller 23 and the support roller 63, the outer peripheral surface of the drive roller 23 and the outer peripheral surface of the support roller 63 are It is pressed against the outer peripheral surface of the strand 50a. In other words, when the strand 50 a is pressed by the support roller 63, the outer peripheral surface of the strand 50 a is pressed against the outer peripheral surface of the constricted portion 25 a of the drive roller 23. The roller holder 60, the radial bearings 61 and 62, and the support roller 63 constitute a force applying unit that applies a pressing force to the element wire 50 a of the coil spring 50 and the outer peripheral surface of the drive roller 23.

  Next, the operation of the piston device 10 will be described with reference to FIGS.

  When the drive shaft 22 of the motor 20 is rotated, the drive roller 23 attached to the drive shaft 22 is rotated together with the drive shaft 22. Here, the strand 50a of the coil spring 50 is pressed against the outer peripheral surface of the drive roller 23 by the weight of the piston 40, the weight of the holding portion 51, the own weight of the coil spring 50, and the like. Further, based on the elastic force generated by the roller holder 60, the strand 50 a is pushed toward the driving roller 23 by the support roller 63, and the outer circumferential surface of the strand 50 a is pushed against the outer circumferential surface of the constricted portion 25 a of the driving roller 23. It has been applied.

  Therefore, a relatively large frictional force acts between the drive roller 23 and the element wire 50 a of the coil spring 50, and the element wire 50 a of the coil spring 50 is sequentially sent out by the drive roller 23. At this time, since the outer peripheral surface of the constricted portion 25a of the drive roller 23 and the outer peripheral surface of the element wire 50a are in line contact, the frictional force acting between the drive roller 23 and the element wire 50a of the coil spring 50 is increased. The sliding between the drive roller 23 and the strand 50a can be suppressed. As the strand 50a is sent out, the strand 50a moves relative to the support roller 63 that is in contact with the drive roller 23 on the opposite side of the strand 50a. Here, since the support roller 63 is rotatably supported by the roller holder 60 via the radial bearing 62, the support roller 63 is rotated by the strand 50a, and between the strand 50a and the support roller 63. The acting frictional force is reduced.

  The coil spring 50 is supported so as to be rotatable about the axis of the coil and to be able to reciprocate in the direction of the axis. For this reason, when the strand 50a of the coil spring 50 is sequentially sent out, the coil spring 50 is moved upward (in the direction of the cylinder 30) along the axis while being rotated about the axis of the coil. At this time, the rotation of the drive roller 23 (drive shaft 22) is decelerated at a reduction ratio according to the diameter of the tip 25 of the drive roller 23 and the diameter of the coil. For example, if the diameter of the coil is 6 times the diameter of the drive roller 23, the drive spring 23 rotates 6 times so that the coil spring 50 rotates once. In this case, the rotation reduction ratio is 6. When the coil spring 50 rotates once, the coil spring 50 is moved in the axial direction by one pitch of the coil. The amount of movement of the coil spring 50 is controlled by the number of rotation steps (rotation amount) of the motor 20.

  When the coil spring 50 is moved upward, the piston 40 connected to the coil spring 50 via the holding portion 51 is moved upward. At this time, since the rotation of the piston 40 is restricted by the rotation preventing member 32, the coil spring 50 and the holding portion 51 rotate with respect to the piston 40. Then, the piston 40 is moved upward as indicated by a two-dot chain line in FIG. 1 in a state in which the rotation about the axis is restricted. As a result, the piston 40 protrudes from the belt upper surface of the belt conveyor, and the work conveyed by the belt hits the side surface of the piston 40 and is stopped.

  Thereafter, when the piston 40 is lowered, the motor 20 is rotated in the direction opposite to that when the piston 40 is raised. Thereby, the strand 50a of the coil spring 50 is sent out in the direction opposite to the upward direction of the piston 40. For this reason, the coil spring 50 is moved downward along the axis while being rotated about the axis of the coil. As a result, as shown by the solid line, the piston 40 is lowered to the initial position.

  The embodiment described above has the following advantages.

  When the drive shaft 22 of the motor 20 rotates, the drive roller 23 having an outer peripheral surface coaxial with the drive shaft 22 is rotated integrally with the drive shaft 22. Here, the coil of the coil spring 50 extends spirally while forming a gap having a larger interval than the outer diameter of the distal end portion 25 of the drive roller 23. And the front-end | tip part 25 of the driving roller 23 is inserted in the clearance gap between coils, and the outer peripheral surface of the driving roller 23 is in contact with the coil strand 50a. For this reason, the motor 20 is arranged not in the axial direction of the coil but in the radial direction, and the dimension of the coil spring 50 in the piston device 10 in the axial direction can be reduced.

  The coil spring 50 is supported via the holding portion 51 so as to be rotatable about the axis of the coil and to be able to reciprocate in the direction of the axis. For this reason, when the drive roller 23 is rotated with the rotation of the drive shaft 22 of the motor 20 and a frictional force acts on the coil from the outer peripheral surface of the drive roller 23, the coil strands 50a are sequentially sent out. Therefore, the coil spring 50 is moved in the direction of the axis while being rotated about the axis of the coil. At this time, the rotation of the drive roller 23 (drive shaft 22) is decelerated at a reduction ratio according to the diameter of the tip 25 of the drive roller 23 and the diameter of the coil. Therefore, the rotational torque generated in the coil spring 50 can be increased more than the rotational torque of the motor 20, and the force for reciprocating the coil spring 50 and consequently the piston 40 can be increased with a simple configuration.

  The piston device 10 is provided with a force applying unit that applies a pressing force to the outer peripheral surface of the coil and the driving roller 23, so that the frictional force that acts between the coil and the outer peripheral surface of the driving roller 23 is increased. Can do. Therefore, slippage between the coil and the outer peripheral surface of the drive roller 23 can be suppressed, and the rotational torque of the drive roller 23 can be efficiently transmitted to the coil spring 50. Specifically, the force applying means includes a support roller 63 inserted in a coil gap on the opposite side of the drive roller 23 across the coil wire 50a, and the coil wire 50a on the outer peripheral surface of the drive roller 23. A roller holder 60 that applies force to the support roller 63 so as to be pressed against the roller is provided. According to such a configuration, a force is applied to the support roller 63 by the roller holder 60, and the coil wire 50 a is pressed against the outer peripheral surface of the drive roller 23.

  The support roller 63 has a constricted portion 65a (cylindrical surface) in contact with the coil wire 50a, and is supported by the roller holder 60 and the radial bearing 62 so as to be rotatable about the axis of the constricted portion 65a. Yes. Therefore, the support roller 63 can be rotated when the coil wire 50a is sequentially sent out by the drive roller 23, and the frictional resistance between the coil wire 50a and the support roller 63 can be reduced. As a result, the drive energy loss of the motor 20 can be reduced. Furthermore, since the outer peripheral surface of the constricted portion 65a and the outer peripheral surface of the strand 50a are in line contact, the contact pressure can be reduced, and a larger force is applied from the support roller 63 to the strand 50a. Is possible.

  Since the axis of the coil spring 50 and the axis of the drive shaft 22 are orthogonal, the axis of the drive shaft 22, that is, the axis of the outer peripheral surface of the drive roller 23 is orthogonal to the circumferential direction of the coil. For this reason, the direction in which the rotational torque of the drive roller 23 is transmitted and the direction in which the coil wire 50a is sent out can be matched. Therefore, the rotational torque of the drive roller 23 can be efficiently transmitted to the coil spring 50.

  A coil spring 50 is employed as the spiral portion that is sequentially sent out by the drive roller 23. According to such a configuration, the spiral portion can be formed by the inexpensive coil spring 50, and when the force is applied from the coil spring 50 to the object, the elastic force of the coil spring 50 is applied to the object. Can be. Therefore, the force for reciprocating the coil spring 50 can be increased while adopting a configuration in which an elastic force is applied from the coil spring 50 to the object.

  Note that the first embodiment may be modified as follows. About the same member as 1st Embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  FIG. 3 is a partial cross-sectional view showing a modification of the piston device 10 of FIG. A flange portion 142 is provided at the upper end of the piston 140 (the end opposite to the coil spring 50). When the piston 140 moves downward from the initial position (predetermined position), the flange portion 142 comes into contact with the rotation preventing member 32. Then, the rotation prevention member 32 and the flange portion 142 (first restriction portion) restrict the piston 140 from moving downward from the initial position. The holding portion 51 is provided with a pin 154 (second restricting portion) extending along the inner circumference of the coil spring 50 in the axial direction of the coil spring 50 so as to be able to rotate integrally with the coil spring 50. The drive roller 123 is formed longer than the drive roller 23 of FIG. 1, and the tip of the drive roller 123 protrudes to the inner periphery of the coil spring 50. The drive roller 123 and the pin 154 are arranged so that the drive roller 123 and the pin 154 come into contact when the coil spring 50 is lowered from above to the initial position (when the coil spring 50 is rotated by a predetermined rotation amount).

  Here, when the movement of the piston 140 is restricted by the anti-rotation member 32 and the flange portion 142 while the coil spring 50 is rotatable, the coil spring 50 coupled to the piston 140 moves in the axial direction. There is a risk of rotating in a regulated state. In this case, the strand 50a of the coil spring 50 moves with respect to the drive roller 123, and there is a possibility that the strand 50a and the outer peripheral surface of the drive roller 123 are separated. And in the state which the strand 50a and the outer peripheral surface of the drive roller 123 left | separated, rotation of the drive roller 123 cannot be transmitted to the strand 50a.

  In this regard, according to the above configuration, the pin 154 restricts the coil spring 50 from rotating from the initial position while maintaining the state in which the wire 50a and the outer peripheral surface of the driving roller 123 are in contact with each other. That is, the rotation of the coil spring 50 is restricted by the pin 154 before the movement of the piston 140 is restricted by the rotation preventing member 32 and the flange portion 142. For this reason, even if it is a case where the rotation prevention member 32 and the flange part 142 which control that the piston 140 moves from an initial position are provided, the strand 50a of the coil spring 50 and the outer peripheral surface of the drive roller 123 leave | separate. Can be suppressed. Accordingly, the rotational torque can be stably transmitted from the driving roller 123 to the strand 50a.

  FIG. 4 is an enlarged view showing a modified example of the driving roller 223 and the supporting roller 265 and their surroundings. In other words, the force applying means for applying the pressing force to the outer peripheral surface of the coil and the driving roller 223 can be configured as follows. The force applying means is such that the support roller 63 inserted in the coil gap on the opposite side of the drive roller 223 across the coil strand 50a and the coil strand 50a are pressed against the outer peripheral surface of the drive roller 223. The roller holder 260 for applying a force to the support roller 63 and the torsion spring 268 are provided.

  The drive roller 223 and the support roller 265 are rotatably supported by a roller holder 260. The torsion spring 268 is provided on the outer periphery of the drive roller 223. One end of the torsion spring 268 is inserted into a hole 269 provided in the roller holder 260, and the other end is applied to the opening 21 a of the bracket 21. In FIG. 5B, the torsion spring 268 applies a rotational force to the roller holder 260 so as to rotate the roller holder 260 clockwise around the drive roller 223. Also with such a configuration, a force is applied to the support roller 63 by the roller holder 260 and the torsion spring 268, and the coil wire 50 a is pressed against the outer peripheral surface of the drive roller 223.

  FIG. 5 is an enlarged view showing another modified example of the driving roller 23 and the supporting roller 63 and the periphery thereof. As shown in the figure, a plurality of support rollers 63 may be inserted into the gap between the coils on the opposite side of the drive roller 23 across the coil wire 50a. Here, two support rollers 63 are provided at intervals. Even in this case, by adopting a configuration according to the force applying means shown in FIG. 2 or a structure according to the force applying means shown in FIG. It can be pressed against the surface. Instead of the support roller 63, a sliding member that slides with the coil wire 50a may be provided.

  FIG. 6 is a partial cross-sectional view showing another modification of the piston device 10 of FIG. As shown in the figure, as another modification of the applying means, the coil spring 50 is moved downward (in the direction opposite to the cylinder 30) so that the wire 50a of the coil spring 50 is pressed against the outer peripheral surface of the drive roller 23. It is also possible to employ a configuration in which a tension spring 360 (biasing portion) that biases the coil spring 50 is supported, and the tension spring 360 is supported so as to rotate integrally with the coil spring 50.

  Both end portions of the rotation pin 361 are slidably engaged with an annular groove 362 provided on the inner peripheral surface of the lower end portion (end portion opposite to the cylinder 30) of the body 11. For this reason, the rotation pin 361 is supported rotatably about the axis of the coil spring 50 in a state where movement of the coil spring 50 in the axial direction is restricted. One end of the tension spring 360 is fixed to the holding portion 51 via a bolt 341, and the other end is centered on the axis of the tension spring 360 (the axis of the coil spring 50) by the body 11 via the rotation pin 361. It is rotatably supported.

  According to such a configuration, the coil spring 50 is biased downward by the tension spring 360, and the element wire 50 a (single) of the coil spring 50 is pressed against the outer peripheral surface of the drive roller 23. Therefore, the frictional force acting between the strand 50a and the outer peripheral surface of the drive roller 23 can be increased. Further, since the tension spring 360 is supported by the body 11 via the rotation pin 361 so as to be integrally rotatable with the coil spring 50, the coil spring 50 is twisted when the coil spring 50 is rotated. Can be suppressed. Instead of the tension spring 360, a tension rubber formed of elastic rubber or the like can be used.

  As another modification of the force applying means, the drive roller 23 may be formed of a magnet so that the coil wire 50 a is pressed against the outer peripheral surface of the drive roller 23.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings. In this embodiment, it is embodied as a hand device attached to the wrist of an articulated robot.

  FIG. 7 is a partial cross-sectional view showing the hand device 410 of the present embodiment. As shown in the figure, the hand device 410 includes a body 411, a stepping motor 420, a rod 440, a coil spring 450, a grip piece 444A, and the like. The vertical direction in FIG. 7 coincides with the vertical direction when the hand device 410 is attached in the basic posture of the robot. In this state, the hand device 410 reciprocates the rod 440 in the horizontal direction.

  The body 411 is made of a metal material or the like and has a bottomed cylindrical shape. An opening 412 is provided on the side of the body 411, and a gripping mechanism 470 is attached to one end of the body 411 in the axial direction. A stepping motor 420 (motor) is attached to the opening 412 via a bracket 421 having an opening 421a. The motor 420 has a drive shaft 422, and the motor 420 is attached to the body 411 so that the axis of the body 411 and the axis of the drive shaft 422 are perpendicular to each other.

  The drive shaft 422 is inserted from the outside to the inside of the body 411 through the opening 421 a of the bracket 421 and the opening 412 of the body 411. A driving roller 423 is attached to the tip of the driving shaft 422. The drive roller 423 (drive member) is formed in a columnar shape and rotates integrally with the drive shaft 422. The axis of the drive roller 423 coincides with the axis of the drive shaft 422. The drive roller 423 has an outer peripheral surface that is coaxial with the drive shaft 422.

  A through hole 414 is provided at the center of one end of the body 411 in the axial direction. The center of the through hole 414 coincides with the axis of the body 411. A cylindrical actuating member 441 is inserted into the through hole 414. The operating member 441 (reciprocating member) is supported by the body 411 via the sliding bearing 435 so as to be reciprocable in the axial direction of the body 411. The axis of the operating member 441 coincides with the axis of the body 411. A key groove 441a is provided on the outer peripheral surface of the operating member 441 so as to extend in the axial direction thereof. The tip of a pin 432 is inserted into the key groove 441a through a through hole provided in the body 411. Therefore, the actuating member 441 can reciprocate in the axial direction in a state where rotation about the axis is restricted.

  A rod 440 is fixed to the end of the operating member 441 on the motor 420 side. The rod 440 is formed in a columnar shape, and annular metal bushes 433 and 434 are provided on the outer circumferences of both ends thereof. A flange 440a is provided at the end of the rod 440 where the metal bush 434 is provided. The flange 440a is in contact with the side surface of the metal bush 434, and the flange 440a prevents the metal bush 434 from coming off from the rod 440.

  A holding portion 451 of a coil spring 450 is provided between the metal bushes 433 and 434 on the outer periphery of the rod 440. The holding portion 451 is formed in a cylindrical shape with a metal material or the like, and a flange portion 451a is provided at one end thereof. A slight gap (clearance) is provided between the outer peripheral surface of the rod 440 and the inner peripheral surface of the holding portion 451. The outer peripheral surface of the flange portion 451a is slidably in contact with the inner peripheral surface of the body 411.

  Both end portions in the axial direction of the holding portion 451 are rotatably supported by a rod 440 via metal bushes 433 and 434. The axis of the holding portion 451 and the axis of the rod 440 coincide with the axis of the body 411 and the axis of the operating member 441. In addition, part of both end surfaces in the axial direction of the holding portion 51 are in contact with the end surfaces of the metal bushes 433 and 434, respectively. For this reason, the axial load acting between the rod 440 and the holding portion 451 is received by the metal bushes 433 and 434.

  The coil spring 450 is attached to the flange portion 451 a of the holding portion 451. One end of the coil spring 50 (driven member) is fixed to the end portion of the holding portion 451 by caulking the flange portion 451a. The axis of the coil spring 450 coincides with the axis of the body 411. For this reason, the coil spring 450 is supported by the rod 440 via the holding portion 451 so as to be rotatable about the axis of the coil spring 450. The coil spring 450 is supported by the body 411 through the rod 440, the actuating member 441, and the sliding bearing 435 so as to be reciprocally movable in the axial direction. At this time, the flange portion 451 a of the holding portion 451 is guided in the axial direction by the inner peripheral surface of the body 411.

  The coil (spiral portion) of the coil spring 450 extends spirally while forming a gap having a larger interval than the outer diameter of the tip end portion 425 of the drive roller 423. That is, the distance between the coil wire 450 a (single) and the wire 450 a (single) is wider than the outer diameter of the tip 425 of the drive roller 423. And the front-end | tip part 425 of the drive roller 423 is inserted in the clearance gap between the strands 450a and 450a of a coil.

  The wire 450a of the coil spring 450 is in contact with the right side surface (outer peripheral surface) of the drive roller 423 in FIG. That is, the tip end portion 425 of the drive roller 423 is inserted into the gap of the coil so that the outer peripheral surface of the drive roller 423 is in contact with the element wire 450a of the coil spring 450. And the motor 420 is attached to the body 411 so that it may be in such a state. The axis of the drive shaft 422 of the motor 420 is perpendicular to the axis of the coil spring 450.

  Next, the gripping mechanism 470 will be described with reference to FIG. FIG. 8 is a partial cross-sectional view of the gripping mechanism 470 as viewed from above. The gripping mechanism 470 includes cam members 443A and 443B, a torsion spring 446, gripping pieces 444A and 444B, and the like.

  In the body 411, the operating member 441 is inserted into the gripping mechanism 470. The body 411 is provided with a pair of support pins 447 symmetrically across the operating member 441. In addition, the body 411 is provided with a pair of detent pins 445 symmetrically with the operation member 441 interposed therebetween. The axis of the support pin 447 and the axis of the detent pin 445 are perpendicular to the axis of the actuating member 441. The axis of the support pin 447 and the axis of the detent pin 445 are parallel to each other.

  The gripping pieces 444A and 444B are supported by the body 411 so as to be slidable in a direction perpendicular to both the axis of the operating member 441 and the axis of the detent pin 445 (support pin 447). That is, the gripping pieces 444A and 444B slide so as to approach and separate from each other. The gripping mechanism 470 grips the workpiece by sandwiching the workpiece between the gripping piece 444A and the gripping piece 444B. The gripping pieces 444A and 444B are provided with action pins 448 in parallel with the support pins 447 and the rotation prevention pins 445, respectively.

  Cam members 443A and 443B are rotatably supported by support pins 447, respectively. The actuating member 441 is provided with a coupling pin 442 in parallel with the support pin 447, the detent pin 445, and the action pin 448. The cam members 443A and 443B are also rotatably supported by the coupling pins 442, respectively. The cam members 443A and 443B are provided with notches 449, respectively. An action pin 448 is slidably engaged with the notch 449. When the cam members 443A and 443B are rotated about the support pins 447, the gripping pieces 444A and 444B are slid toward and away from each other via the action pins 448.

  A torsion spring 446 is attached to each support pin 447. One end of the torsion spring 446 is in contact with the detent pin 445, and the other end is in contact with the action pin 448. Each torsion spring 446 generates a force that rotates the action pin 448 around the support pin 447. Accordingly, the grip pieces 444A and 444B are urged by the respective torsion springs 446 in a direction away from each other. At this time, a force that moves the operating member 441 in the direction of the gripping pieces 444A and 444B acts on the operating member 441.

  Therefore, a force that moves the coil spring 450 toward the gripping mechanism 470 acts on the coil spring 450 via the rod 440, the metal bush 434, and the holding portion 451. Thereby, the outer peripheral surface of the strand 450a is pressed against the outer peripheral surface of the drive roller 423. The support spring 447, the torsion spring 446, the action pin 448, the anti-rotation pin 445, the cam members 443A and 443B, the coupling pin 442, the operation member 441, the rod 440, the metal bush 434, and the holding portion 451, A force applying means for applying a pressing force to each other is configured on the outer peripheral surfaces of the wire 450 a and the driving roller 423.

  Next, a rotation preventing portion that restricts the coil spring 450 from rotating from the initial position (predetermined position) will be described. FIG. 9 is an enlarged view showing the drive roller 423 and the rotation stopper 454 and the periphery thereof. FIG. 4A is a view of the coil spring 450 and the holding portion 451 viewed from the axial direction, and FIG. 4B is a view of the coil spring 450 and the holding portion 451 viewed from the axial direction of the drive roller 423. is there.

  The flange portion 451a of the holding portion 451 is provided with a rotation preventing portion 454 (second restricting portion) extending along the outer periphery of the coil spring 450 in the axial direction of the coil spring 450 so as to be integrally rotatable with the coil spring 450. . The front end 425 of the drive roller 423 protrudes to the inner periphery of the coil spring 450. Then, when the coil spring 450 is moved from the right side in FIG. 9 to the initial position (when the coil spring 450 is rotated by a predetermined rotation amount), the drive roller 423 and the anti-rotation portion are arranged so that the drive roller 423 and the anti-rotation portion 454 come into contact with each other. 454 is arranged.

  Next, the operation of the hand device 410 will be described with reference to FIGS. FIG. 7 shows a state where the coil spring 450 is in the initial position.

  There is a possibility that the coil spring 450 may rotate about the axis after stopping the movement from right to left in FIG. In this case, the wire 450a of the coil spring 450 moves relative to the drive roller 423, and there is a possibility that the wire 450a and the outer peripheral surface of the tip end portion 425 of the drive roller 423 are separated. And in the state which the strand 450a and the outer peripheral surface of the front-end | tip part 425 of the drive roller 423 have left | separated, the rotational torque of the drive roller 423 cannot be transmitted to the strand 450a.

  In this regard, the rotation preventing portion 454 restricts the coil spring 450 from rotating from the initial position while maintaining the state in which the element wire 450a and the outer peripheral surface of the driving roller 423 are in contact with each other. For this reason, it can suppress that the strand 450a of the coil spring 450 and the outer peripheral surface of the drive roller 423 can separate, and can transmit rotational torque from the drive roller 423 to the strand 450a stably.

  When the drive shaft 422 of the motor 420 is rotated, the drive roller 423 attached to the drive shaft 422 is rotated integrally with the drive shaft 422. Here, based on the elastic force generated by the torsion spring 446, the outer peripheral surface of the wire 450 a of the coil spring 450 is pressed against the outer peripheral surface of the tip end portion 425 of the drive roller 423. Therefore, a relatively large frictional force acts between the drive roller 423 and the wire 450a of the coil spring 450, and the wire 450a of the coil spring 450 is sequentially sent out by the drive roller 423.

  The coil spring 450 is supported so that it can rotate about the axis of the coil and can reciprocate in the direction of the axis. For this reason, when the wire 450a of the coil spring 450 is sequentially sent out, the coil spring 450 is rotated about the axis of the coil and moved to the opposite side of the gripping mechanism 470 along the axis. At this time, the rotation of the drive roller 423 (drive shaft 422) is decelerated at a reduction ratio according to the diameter of the tip end portion 425 of the drive roller 423 and the diameter of the coil. When the coil spring 450 rotates once, the coil spring 450 is moved in the axial direction by one pitch of the coil. The amount of movement of the coil spring 450 is controlled by the number of rotation steps (rotation amount) of the motor 420.

  When the coil spring 450 is moved to the side opposite to the gripping mechanism 470, the operation member 441 connected to the coil spring 450 via the holding portion 451 and the rod 440 is moved to the motor 420 side. At this time, since the rotation of the actuating member 441 is restricted by the key groove 441 a and the pin 432, the coil spring 450 and the holding portion 451 rotate with respect to the actuating member 441 and the rod 440. Then, the operation member 441 is moved to the side away from the gripping mechanism 470 as shown in FIG. 10 in a state where the rotation around the axis is restricted. As a result, in the gripping mechanism 470, the cam members 443A and 443B are rotated about the support pins 447, respectively, and the gripping pieces 444A and 444B are slid in the approaching direction via the action pins 448. Accordingly, the work is sandwiched between the gripping piece 444A and the gripping piece 444B, and the work is gripped by the gripping mechanism 470.

  Thereafter, when the workpiece is released, the motor 420 is rotated in the direction opposite to that when the workpiece is gripped. Thereby, the strand 450a of the coil spring 450 is sequentially sent out in the reverse direction to the time of holding | grip of a workpiece | work. For this reason, the coil spring 450 is moved toward the gripping mechanism 470 along the axis while being rotated about the axis of the coil. As a result, as shown in FIG. 7, the coil spring 450 is moved to the initial position.

  The embodiment described above has the following advantages. Here, only advantages different from the first embodiment will be described.

  The motor 420 is arranged in the radial direction rather than in the axial direction of the coil with respect to the coil spring 450, and the dimension in the axial direction of the coil spring 450 in the hand device 410 can be reduced. For this reason, when the hand device 410 is attached to the wrist of the articulated robot, the rotational moment due to the weight of the hand device 410 acting on the wrist of the robot can be reduced.

  -Since the hand device 410 includes a force applying unit that exerts a pressing force on the outer peripheral surface of the coil and the driving roller 423, the friction force acting between the coil and the outer peripheral surface of the driving roller 423 is increased. Can do. Therefore, slippage between the coil and the outer peripheral surface of the drive roller 423 can be suppressed, and the rotational torque of the drive roller 423 can be efficiently transmitted to the coil spring 450. In particular, the force applying means is configured by adding a torsion spring 446 and a detent pin 445 to the gripping mechanism 470. For this reason, the change location of the gripping mechanism 470 can be reduced, and the configuration in the vicinity of the drive roller 423 can be simplified as compared with the first embodiment.

  A coil spring 450 is employed as the spiral portion that is sequentially sent out by the drive roller 423. According to such a configuration, the spiral portion can be formed by the inexpensive coil spring 450. Furthermore, when the workpiece is gripped by the gripping mechanism 470, the state in which the elastic force of the coil spring 450 is applied to the workpiece can be maintained. Therefore, it is possible to increase the force for reciprocating the coil spring 450 while adopting a configuration capable of elastically gripping the workpiece.

  In addition, the said 2nd Embodiment can also be deform | transformed and implemented as follows. About the same member as 2nd Embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  Instead of the anti-rotation portion 454 of FIG. 9, as shown in FIG. 11, an anti-rotation pin 554 can be employed. That is, the flange portion 451a of the holding portion 451 is provided with a detent pin 554 (second restricting portion) extending along the outer periphery of the coil spring 450 in the axial direction of the coil spring 450 so as to be able to rotate integrally with the coil spring 450. ing. Even in such a configuration, the rotation of the coil spring 450 from the initial position is restricted by the non-rotating pin 554 while maintaining the state where the element wire 450a of the coil spring 450 and the outer peripheral surface of the drive roller 423 are in contact with each other. Can do.

  Moreover, it is not limited to the said 1st, 2nd embodiment, For example, it can also implement as follows. About the same member as 1st Embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  A helical member 650 and a drive gear 623 shown in FIG. 12 may be employed instead of the coil spring 50 and the drive roller 23 of FIG. 1 or the coil spring 450 and the drive roller 423 of FIG. That is, a plurality of teeth 623a are provided on the outer peripheral surface of the drive gear 623 (drive member), and the portion of the spiral portion 651 that contacts the outer peripheral surface of the drive gear 623 meshes with the teeth 623a of the drive gear 623. A plurality of teeth 651a are provided. The spiral member 650 can be formed of a metal material, resin, or the like.

  According to the above configuration, the teeth 623a provided on the outer peripheral surface of the drive gear 623 mesh with the teeth 651a provided on the portion of the spiral portion 651 that contacts the outer peripheral surface of the drive gear 623. For this reason, the rotational torque of the drive gear 623 can be efficiently transmitted to the spiral portion 651. As a result, the rotational torque generated in the spiral member 650 (driven member) can be further increased, and the force for reciprocating the spiral member 650 can be further increased.

  Note that a plurality of teeth 651 a that mesh with the teeth 623 a of the drive gear 623 can also be provided at portions of the coil springs 50 and 450 that are in contact with the outer peripheral surface of the drive gear 623. At this time, a plurality of teeth that mesh with the teeth 623 a of the drive gear 623 can be provided on the entire circumference of the strands 50 a and 450 a of the coil springs 50 and 450.

  In the first and second embodiments, the axes of the drive shafts 22 and 422 of the motors 20 and 420 are perpendicular to the axis of the coil springs 50 and 450. However, the drive shafts 22 and 422 of the motors 20 and 420 are used. Can be inclined with respect to the axis of the coil springs 50 and 450.

  In place of the stepping motors 20 and 420 (synchronous motors), asynchronous motors may be employed.

  DESCRIPTION OF SYMBOLS 10 ... Piston apparatus (reciprocating drive apparatus), 11,411 ... Body, 20,420 ... Stepping motor (motor), 22 ... Drive shaft, 23, 123, 223, 423 ... Drive roller (drive member), 30 ... Cylinder, 40, 140 ... piston (reciprocating member), 50, 450 ... coil spring (driven member), 50a, 450a ... strand (single), 410 ... hand device (reciprocating driving device), 470 ... gripping mechanism, 623 ... Drive gear (drive member), 650 ... spiral member (driven member), 651 ... spiral portion.

Claims (10)

A motor having a drive shaft;
A drive member having an outer peripheral surface coaxial with the drive shaft and rotating integrally with the drive shaft;
It has a spiral portion that extends in a spiral manner while forming a gap having a larger interval than the outer diameter of the drive member, and is supported so as to be rotatable about the axis of the spiral portion and reciprocating in the direction of the axis. Driven members,
With
The reciprocating drive device, wherein the drive member is inserted into the gap of the spiral portion, and the outer peripheral surface of the drive member is in contact with the spiral portion.   2. The reciprocating drive device according to claim 1, further comprising a force applying unit that applies a pressing force to the outer peripheral surface of the spiral portion and the drive member.   The force applying means includes a rear part inserted in the gap of the spiral part opposite to the drive member across a single part of the spiral part, and a single part of the spiral part is the outer periphery of the drive member. The reciprocating drive device according to claim 2, further comprising a force applying portion that applies a force to the rear portion so as to be pressed against a surface.   The reciprocating drive device according to claim 3, wherein the rear portion has a cylindrical surface in contact with the spiral portion, and is supported by the force application portion so as to be rotatable about an axis of the cylindrical surface. .   The force applying means includes an urging portion that urges the driven member so that a single portion of the spiral portion is pressed against the outer peripheral surface of the driving member, and the urging portion is the driven member. The reciprocating drive device according to claim 2, wherein the reciprocating drive device is supported so as to be integrally rotatable. A reciprocating member connected to the driven member and supported so as to reciprocate in the direction of the axis of the spiral portion;
A first restricting portion for restricting the reciprocating member from moving in a direction of the axis of the spiral portion from a predetermined position;
A second restricting portion that restricts the driven member from rotating more than a predetermined amount of rotation while maintaining a state where the spiral portion and the outer peripheral surface of the driving member are in contact with each other;
The reciprocating drive device according to any one of claims 1 to 5. The second restricting portion extends along the spiral portion in the axial direction of the spiral portion, and is provided so as to be integrally rotatable with the driven member.
The drive member and the second restricting portion are arranged so that the drive member and the second restricting portion are in contact with each other when the driven member is rotated by the predetermined rotation amount. Reciprocating drive device. A plurality of teeth are provided on the outer peripheral surface of the drive member,
The reciprocating drive device according to any one of claims 1 to 7, wherein a plurality of teeth that mesh with the teeth of the drive member are provided in a portion of the spiral portion that contacts the outer peripheral surface of the drive member. .   The reciprocating drive device according to any one of claims 1 to 8, wherein the axis of the spiral portion and the axis of the drive shaft are orthogonal to each other.   The reciprocating drive device according to claim 1, wherein the spiral portion is formed by a coil spring.

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