JP2017166520A - Screw feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw feeding device having a simple configuration and capable of making its size small.SOLUTION: This invention relates to a screw feeding device for giving a rotational displacement to an inclining leg part 44 extending from an inclined body 4 that is rotatable within a specified angular range. The screw feeding device comprises a screw rod 37 rotated by a motor 39 and a nut 43 engaged in thread with the screw rod. The extremity end of the inclined leg part is formed with V-groove facing toward a rotation center of the inclined leg part, a recess 45 is formed to extend from the extremity end along a center of the V-groove, the screw rod is inserted into the recess while not being contacted with it, the nut has a spherical surface concentric with an axis center of the nut, the spherical surface is contacted with the V-groove, a stopper for restricting a rotation of the nut is arranged between the inclined leg part and the nut and a spring 49a for contacting the spherical surface with the V-groove is arranged between the inclined leg part and the nut.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a screw feeding device used for a movable part of a precision machine.

  Precision machines and surveying instruments are equipped with a leveling device in order to make the device a highly accurate horizontal posture. The leveling device is leveled by tilting the mounting table on which the surveying instrument main body is installed with two horizontal axes.

  A screw feeding device is used as the device for tilting. When a screw feeding device is used for a mechanism in which the movable portion tilts, the screw feeding device gives a straight displacement to the movable portion, and the movable portion tilts due to the straight displacement. Relative inclination accompanying the tilting of the movable part occurs in the connecting part. Therefore, the connecting portion is required to have a function of absorbing the relative inclination and the positional deviation accompanying the inclination.

  Conventionally, as a method for connecting the tilting portion and the straight portion, it has been considered to use a universal joint or the like, but it has not been a small and simple connection method.

JP 2000-149467 A

  The present invention provides a screw feeder that can be reduced in size with a simple configuration.

  The present invention relates to a screw feeding device that applies rotational displacement to a tilting leg extending from a tilted body that can rotate within a predetermined angle range, the screw feeding device including a screw rod that is rotated by a motor, and the screw. A nut that is screwed to the rod, and a V-groove is formed at the tip of the tilting leg toward the center of rotation of the tilting leg, and a notch is formed from the tip along the center of the V-groove. The screw rod is inserted through the notch in a non-contact manner, the nut has a spherical surface concentric with the axis of the nut, the spherical surface is in contact with the V groove, and between the tilting leg and the nut. Is a screw feeding device in which a rotation stop for restraining the rotation of the nut is provided, and a spring for contacting the spherical surface and the V-groove is provided between the tilting leg and the nut.

  Further, the present invention relates to a screw feeding device in which the spring is provided such that the acting direction of the spring force is inclined with respect to the axis of the screw rod.

  Further, the present invention relates to a screw feeding device in which the spring is provided such that a component force of the spring force generates a rotational force about the axis of the screw rod on the nut.

  Further, the present invention relates to a screw feeding device in which two springs are provided sandwiching the screw rod, and the two springs are set so that spring forces are different.

  Further, the present invention relates to a screw feeding device in which the spring is provided such that the acting direction of the spring force is inclined with respect to a plane including the axis of the screw rod.

  According to the present invention, the detent includes a detent pin provided at the tip of the tilting leg and a slit groove formed in the nut, and the detent pin is slidable in the slit groove. This relates to the screw feeding device fitted to the.

  Furthermore, in the present invention, the rotation includes a rotation pin provided at a tip end portion of the tilting leg portion, and a pin protruding from the nut in a direction perpendicular to the axis of the screw rod. Further, the present invention relates to a screw feeding device in which the rotation pin and the pin are brought into contact with each other.

  According to the present invention, there is provided a screw feeding device that applies rotational displacement to a tilting leg extending from a tilted body that can rotate within a predetermined angle range, the screw feeding device being a screw rod that is rotated by a motor; A nut that is screwed to the screw rod, and a V-groove is formed at the tip of the tilting leg toward the center of rotation of the tilting leg, and is cut out from the tip along the center of the V-groove. The screw rod is inserted through the notch in a non-contact manner, the nut has a spherical surface concentric with the axial center of the nut, the spherical surface is in contact with the V-groove, the tilting leg portion and the nut A rotation stop is provided between the nut and the nut, and a spring is provided between the tilting leg and the nut to bring the spherical surface and the V-groove into contact with each other. Displacement is via the nut Becomes configured to be transmitted to the contact the tilting legs, structure exhibits an excellent effect that is extremely simplified.

It is a perspective view of the leveling apparatus provided with the screw feeding apparatus of a present Example. (A) is an A arrow view of FIG. 1, (B) is a B arrow view of FIG. (A) is a C arrow view of FIG. 1, (B) is a D arrow view of FIG. It is an AB arrow line view of FIG. It is the perspective view which looked at the Y-axis frame from the lower part. It is a bottom view of a leveling device. (A) (B) (C) is explanatory drawing of the tilting operation | movement of the Y-axis frame by a Y-axis screw feeder. (A) (B) is explanatory drawing which shows an example of the spring effect | action made to act between a nut and a lower end part.

  Embodiments of the present invention will be described below with reference to the drawings.

  A case where the screw feeding device according to the embodiment of the present invention is used as a feeding device of a leveling device will be described.

  1 to 3 show a leveling device 1 provided with the screw feeding device of the present embodiment. In the figure, reference numeral 2 denotes a main body frame which is a fixing portion of the leveling device 1, and the main body frame 2 Is substantially ring-shaped, and an X-axis frame 3 is provided concentrically inside the main body frame 2, and a Y-axis frame 4 is provided concentrically on the X-axis frame 3. Bosses 5 are projected from required positions on the upper surface of the Y-axis frame 4 and at four places in the illustration in FIG. A fitting portion and an upper case for attaching a device to be leveled, for example, a surveying device main body, are attached to the boss 5.

  The X-axis frame 3 is tiltable about the X-axis 12 (is rotatable within a predetermined angle range), and the Y-axis frame 4 is tiltable with respect to the X-axis frame 3 about the Y-axis 13. (It is freely rotatable within a predetermined angle range). The X axis 12 and the Y axis 13 are set so as to be orthogonal to each other and exist in the same plane.

  A first fixed leg 7 extends downward from the lower surface of the main body frame 2, and an X-axis screw feeder 8 is provided at the lower end of the first fixed leg 7. A second fixed leg 9 extends downward from the lower surface of the X-axis frame 3, and a Y-axis screw feeding device 10 is provided at the lower end of the second fixed leg 9. The first fixed leg portion 7 may be integrally formed with the main body frame 2 by die casting or the like, or may be attached to the main body frame 2 as a separate part. Similarly, the second fixed leg portion 9 may be integrally formed with the X-axis frame 3 by die casting, or may be attached to the X-axis frame 3 as a separate part.

  Next, a support mechanism for tiltably supporting the X-axis frame 3 and the Y-axis frame 4 will be described.

  The X-axis frame 3 is provided with shaft portions 15 and 16 having a semicircular cross section that rises to a required amount and then extends along the X-axis 12 toward the outer peripheral side. The shaft portions 15 and 16 overlap the main body frame 2.

  FIG. 2A is a view taken in the direction of arrow A in FIG. 1, and a bearing boss 17 protrudes from a portion of the main body frame 2 facing the shaft portion 15, and the bearing boss 17 has a conical shape. A one-ball receiving hole 18 is formed. A first conical hole 19 is formed at a position facing the first ball receiving hole 18 on the lower surface of the shaft portion 15, and a steel ball 21 is interposed between the first ball receiving hole 18 and the first conical hole 19. Is installed.

  FIG. 2B is a view taken in the direction of arrow B in FIG. 1, and a bearing boss 22 protrudes from a portion of the main body frame 2 facing the shaft portion 16, and the bearing boss 22 has a conical shape. A one-ball receiving hole 23 is formed. A first V groove 24 is engraved in parallel with the X axis 12 at a position facing the first ball receiving hole 23 on the lower surface of the shaft portion 16, and the first V groove 24 and the first ball receiving hole 23 are A steel ball 25 is interposed between them.

  The steel balls 21 and 25 are located on the X-axis 12, and the first V-groove 24 has a processing error between the first ball receiving holes 18 and 23, or a molded part dimensional error, and the first ball receiving hole 23 and the Absorbs processing errors between the first V-grooves 24 or molded part dimensional errors. Therefore, the assembly with respect to the main body frame 2 only needs to place the X-axis frame 3 on the main body frame 2 via the steel balls 21 and 25. In addition, a spring (not shown) is provided between the X-axis frame 3 and the main body frame 2, and the steel balls 21 and 25 are connected to the X-axis frame 3 and the main body frame 2 at a required surface pressure. It is kept stable during

  The support mechanism for the Y-axis frame 4 is the same as the support mechanism for the X-axis frame 3.

  3A is a view as viewed from the arrow C in FIG. 1, and FIG. 3B is a view as viewed from the arrow D in FIG.

  Bearing bosses 26 and 27 are provided on the Y-axis 13 at the periphery of the X-axis frame 3, and conical second ball receiving holes 28 and 29 are formed in the bearing bosses 26 and 27, respectively. . A second conical hole 30 is formed at a position facing the second ball receiving hole 28 of the Y axis frame 4, and a Y axis 13 is positioned at a position facing the second ball receiving hole 29 of the Y axis frame 4. A V-groove 31 is engraved in parallel.

  A steel ball 32 is interposed between the second ball receiving hole 28 and the second conical hole 30, and a steel ball 33 is interposed between the second ball receiving hole 29 and the V groove 31. Is done.

  The steel balls 32 and 33 are located on the Y-axis 13, and the V groove 31 is a processing error related to the second ball receiving hole 28, the second ball receiving hole 29, the second conical hole 30, and the V groove 31. Alternatively, it absorbs molded part dimensional errors.

  The Y-axis frame 4 can be assembled only by placing the Y-axis frame 4 on the X-axis frame 3 via the steel balls 32 and 33. A spring (not shown) is provided between the X-axis frame 3 and the Y-axis frame 4, and the steel balls 32 and 33 are connected to the X-axis frame 3 and the Y-axis frame 4 with a required surface pressure. It is kept stable during

  Next, the X-axis screw feeder 8 and the Y-axis screw feeder 10 will be described with reference to FIGS.

  Since the X-axis screw feeder 8 and the Y-axis screw feeder 10 have the same configuration, the Y-axis screw feeder 10 will be described below.

  The Y-axis screw feeder 10 has a fixing bracket 35 that is fixed to the second fixed leg portion 9 as a frame member.

  A spanning screw rod 37 is rotatably provided between the end plates 35a, 35b of the fixing bracket 35. A driven gear 38 is fixed to an end portion of the screw rod 37 that passes through the end plate 35a.

  A motor 39 is attached to the end plate 35a. As the motor 39, a motor capable of controlling the rotation angle such as a pulse motor is used.

  A drive gear 41 is fixed to the output shaft of the motor 39, and an intermediate gear 42 is provided between the drive gear 41 and the driven gear 38 (see FIG. 6). A large diameter gear 42 a of the intermediate gear 42 meshes with the drive gear 41, and a small diameter gear 42 b of the intermediate gear 42 meshes with the driven gear 38. Thus, the rotation of the motor 39 is decelerated by the gear train of the drive gear 41, the intermediate gear 42, and the driven gear 38 and transmitted to the screw rod 37.

  A nut 43 is screwed onto the screw rod 37. The tilt leg 44 integrally formed with the Y-axis frame 4 extends vertically downward with the Y-axis frame 4 in a horizontal state, and the lower end 44 a of the tilt leg 44 engages with the nut 43. To do.

  The surface of the nut 43 that contacts the lower end 44 a is a spherical surface that is concentric with the axis of the nut 43. The lower end 44a is formed with a V-groove 44b extending in the direction toward the center of rotation of the tilting leg 44 (in the present embodiment, the vertical direction), and the tapered surface forming the V-groove 44b is the nut 43. Abut. A slit-like notch 45 is formed at the center of the tilting leg 44 from the lower end of the lower end 44a (see FIG. 5). The width of the notch 45 is larger than the diameter of the screw rod 37. Even when the screw rod 37 is inserted without contact and the tilting leg 44 tilts, the lower end 44a and the screw rod 37 interfere with each other. It is supposed not to.

  The lower end portion 44a is provided with a rotation pin 46 that protrudes in the horizontal direction when the Y-axis frame 4 is in a horizontal state. A slit groove 47 is formed in the nut 43 in parallel with the axis of the screw rod 37, and the rotation pin 46 is slidably fitted in the slit groove 47. The rotation pin 46 and the slit groove 47 constitute a rotation that restrains relative rotation between the tilting leg portion 44 and the nut 43.

  The nut 43 is provided with spring hooks 48a and 48b projecting in the horizontal direction, and springs 49a and 49b are stretched between the spring hooks 48a and 48b and the lower end portion 44a (see FIG. 6).

  The springs 49 a, 49 b bring the nut 43 and the lower end 44 a into close contact with each other with a predetermined surface pressure, and the tilting leg 44 follows the displacement of the nut 43.

  The displacement of the springs 49a and 49b is caused by the tilting of the tilting leg 44 with respect to the nut 43, and is slight. Therefore, it is not necessary to consider the increase or decrease of the spring force with respect to the spring displacement in the design of the springs 49a and 49b, and the design of the springs 49a and 49b is facilitated.

  Next, as shown in FIGS. 8A and 8B, the spring 49a provides a spring action between the spring hook 48a and the lower end 44a, and the spring 49b has the spring hook. Different from the spring action applied between 48b and the lower end 44a, the action direction of the spring force and the spring force or at least one of the action direction of the spring force and the spring force is set. In addition to the above description, it goes without saying that various methods can be considered as a method for making the spring action of the springs 49a and 49b different.

  By making the spring action of the spring 49 a different from the spring action of the spring 49 b, the spring force on the spring hooks 48 a and 48 b becomes asymmetric with respect to the screw rod 37. For this reason, the acting direction of the resultant force of the springs 49a and 49b is not parallel to the axis of the screw rod 37 (becomes a direction inclined with respect to the axis).

  The resultant force of the springs 49 a and 49 b gives a rotational force in a direction in which the axis of the nut 43 is inclined with respect to the axis of the screw rod 37. Due to this rotational force, the nut 43 rotates relative to the screw rod 37 by a gap, so that the nut 43 comes into contact with each other, so that backlash and backlash between the nut 43 and the screw rod 37 are suppressed. The

  That is, the springs 49a and 49b bring the nut 43 and the lower end 44a into close contact with each other and suppress backlash and backlash between the nut 43 and the screw rod 37.

  The X-axis frame 3 is tilted about the X-axis 12 by the X-axis screw feeder 8, and the Y-axis frame 4 itself is tilted about the Y-axis 13 by the Y-axis screw feeder 10. The Y-axis frame 4 tilts in the horizontal biaxial direction.

  As shown in FIG. 5, a sensor support member 51 is provided integrally with the Y-axis frame 4 on the back surface of the Y-axis frame 4, and the X-axis is perpendicular to the X-axis 12 on the sensor support member 51. A tilt sensor 53 is provided, and a Y-axis tilt sensor 54 is provided in a direction orthogonal to the Y-axis 13.

  Leveling by the leveling device 1 is performed by driving the X-axis screw feeding device 8 and the Y-axis screw feeding device 10 so that the X-axis tilt sensor 53 and the Y-axis tilt sensor 54 detect horizontal. Is executed.

  With reference to FIGS. 7A to 7C, the operation of the X-axis screw feeder 8 and the Y-axis screw feeder 10 will be further described. 7A to 7C show the case where the Y-axis frame 4 is tilted, the same applies to the case where the X-axis frame 3 is tilted.

  FIG. 7A shows a state in which the Y-axis frame 4 is inclined to the right side (the right side is lowered) in the drawing.

  The screw rod 37 is rotated clockwise by the motor 39 via the driven gear 38. Since the rotation of the nut 43 is restrained by the rotation pin 46, the nut 43 is displaced to the left (when the screw rod 37 is a right-hand thread).

  Since the nut 43 and the lower end portion 44a are connected by the springs 49a and 49b, the lower end portion 44a is displaced to the left integrally with the nut 43, and the tilting leg portion 44 is centered on the Y axis 13. Rotate clockwise.

  In order to return the Y-axis frame 4 from the state inclined rightward in FIG. 7A to the horizontal state shown in FIG. 7B, the screw rod 37 is rotated counterclockwise. The nut 43 is displaced rightward, the lower end 44a is moved rightward, and the Y-axis frame 4 becomes horizontal. The horizontal of the Y-axis frame 4 is detected by the X-axis tilt sensor 53.

  Further, in order to obtain the left inclination shown in FIG. 7C, the screw rod 37 is further rotated counterclockwise. The nut 43 further moves to the right, the tilting leg 44 tilts counterclockwise about the Y axis 13, and the Y axis frame 4 tilts to the left.

  Thus, the tilting leg portion 44 tilts following the linear displacement of the nut 43. Further, since the nut 43 is spherical and contacts the V-groove 44b, the linear displacement of the nut 43 is smoothly converted into the rotational displacement of the tilting leg 44.

  Further, since the spherical surface of the nut 43 engages with the V groove 44b, sliding is allowed in the longitudinal direction of the V groove 44b, and displacement is restricted in the width direction of the V groove 44b. The Accordingly, the rotational displacement of the tilting leg 44 is restricted by the straight movement of the nut 43, resulting in an accurate circular orbit.

  An example of the action of the springs 49a and 49b will be described with reference to FIGS. 8 (A) and 8 (B).

  First, in FIG. 6, the spring forces of the spring 49a and the spring 49b are made different. For example, when the spring force of the spring 49 a is made stronger than that of the spring 49 b, a clockwise rotational force acts on the nut 43 with respect to the paper surface of FIG. The backlash and backlash between the screw rod 37 and the nut 43 are suppressed.

  Next, the springs 49a and 49b or any one of them is attached to be inclined with respect to a plane including the axis of the screw rod 37 as shown in FIG. The spring force acts in a direction inclined with respect to the axis of the screw rod 37, and due to the component force of the spring force orthogonal to the axis, a rotational force M about the screw rod 37 is applied to the nut 43. It works (FIG. 8B). What restricts the rotation of the nut 43 is the engagement between the rotation pin 46 and the slit groove 47, and the rotation pin 46 always comes into contact with the slit groove 47 from one direction.

  Accordingly, backlash and backlash between the rotation pin 46 and the slit groove 47 are also suppressed by the spring action of the springs 49a and 49b. In the above embodiment, two springs are used, but a single spring may be used.

  Thus, the member tilted by the screw feeding device having a simple configuration can be displaced without backlash and backlash.

  Further, the backlash and backlash between the screw rod 37 and the nut 43 and the backlash and backlash between the nut 43 and the locking pin 46 can be suppressed by a set of springs. There is no need to do. For this reason, the number of parts is small, and the size can be greatly reduced.

  Needless to say, a separate spring may be provided to apply the rotational force M to the nut 43.

  Further, with respect to the engagement between the rotation pin 46 and the nut 43, instead of providing the slit groove 47 in the nut 43, the nut 43 is arranged in a radial direction (a direction perpendicular to the axis of the screw rod 37). A protruding engagement pin may be provided, and the engagement pin may be brought into contact with the rotation pin 46 to stop the nut 43.

  Furthermore, the rotation pin 46 may be provided in the nut 43, a groove extending in the vertical direction may be formed in the tilting leg portion 44, and the rotation pin 46 and the groove may be engaged. The point is that when the contact position between the nut 43 and the tilting leg 44 changes due to the tilting of the tilting leg 44, no rotational displacement occurs between the rotation pin 46 and the nut 43. Any joint relationship may be used.

  Further, in the above embodiment, the screw feeding device is provided below the main body frame 2, the X-axis frame 3, and the Y-axis frame 4 shown as the tilted body, but even if provided above the tilted body, Even if it is provided on the side, it can be implemented in the same manner, and can be implemented as a device that gives rotational displacement in a predetermined angular range.

DESCRIPTION OF SYMBOLS 1 Leveling device 2 Main body frame 3 X-axis frame 4 Y-axis frame 7 1st fixed leg part 8 X-axis screw feeder 9 2nd fixed leg part 10 Y-axis screw feeder 12 X-axis 13 Y-axis 35 Fixing bracket 37 Screw Rod 38 Driven gear 39 Motor 41 Drive gear 43 Nut 44 Tilt leg 44a Lower end 44b V groove 45 Notch 46 Stop pin 47 Slit groove 48a, 48b Spring hook 49a, 49b Spring 51 Sensor support member 53 X-axis tilt sensor 54 Y Axis tilt sensor

Claims (7)

  A screw feeding device that applies rotational displacement to a tilting leg extending from a tilted body that can rotate within a predetermined angle range, the screw feeding device being screwed into a screw rod that is rotated by a motor A nut is formed at the tip of the tilting leg, a V-groove is formed toward the center of rotation of the tilting leg, and a notch is formed along the center of the V-groove from the tip. The rod passes through the notch without contact, the nut has a spherical surface concentric with the nut axis, the spherical surface contacts the V-groove, and the nut is between the tilting leg and the nut. A screw feeding device in which a rotation stop is provided to restrain rotation, and a spring is provided between the tilting leg and the nut to bring the spherical surface and the V-groove into contact with each other.   The screw feeding device according to claim 1, wherein the spring is provided such that a direction in which a spring force acts is inclined with respect to an axis of the screw rod.   2. The screw feeding device according to claim 1, wherein the spring is provided such that a component force of the spring force generates a rotational force about the axis of the screw rod on the nut. 3.   2. The screw feeding device according to claim 1, wherein two springs are provided sandwiching the screw rod, and the two springs are set to have different spring forces.   The screw feeding device according to claim 1, wherein the spring is provided so that an acting direction of a spring force is inclined with respect to a plane including an axis of the screw rod.   The said stop has a stop pin provided in the front-end | tip part of the said tilting leg part, and the slit groove formed in the said nut, The said stop pin was slidably fitted in this slit groove. Item 2. A screw feeding device according to Item 1.   The detent includes a detent pin provided at the tip of the tilting leg, and a pin projecting from the nut in a direction perpendicular to the axis of the screw rod, and the detent pin and the The screw feeding device according to claim 1, wherein the pin is brought into contact with the screw feeding device.

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