JP2012127460A - Motion mechanism for changing rotational motion to linear motion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motion mechanism for changing rotational motion to linear motion, wherein a male screw member can be directly moved without being loosened in proportion to the rotation of a rotational output shaft.SOLUTION: When a rotational output shaft 12 rotates, a holder 14, a pair of plate springs 18, and a pair of guide members 16 are rotated and a male screw member 22 is integrally rotated with the rotational output shaft 12 via a pin 24 for rotating a male screw member held between leading ends 1604A of protruded plate portions 1604 of a pair of guide members 16. The pair of guide members 16 holds the pin 24 for rotating the male screw member in a way that the pin 24 for rotating the male screw member is movably and integrally rotated with the rotational output shaft 12 at any position in the axial direction of the rotational output shaft 12, and therefore, a problem of looseness between the rotational output shaft 12 and the male screw member 22 is not generated.

Description

  The present invention relates to a motion mechanism that changes rotational motion into linear motion.

For example, when a male screw member arranged coaxially with a rotation output shaft of an actuator such as a motor is linearly reciprocated while being rotated by the rotation output shaft, the rotation output shaft and the male screw member can be integrally rotated and separated from each other. Further, a female screw member having a female screw that is movably coupled to the male screw member and is engaged with the male screw of the male screw member is supported on the housing of the actuator or the base side that supports the housing.
Conventionally, when a rotary output shaft and a male screw member are coupled so as to be able to rotate together and move away from each other, for example, a cylindrical body having a long hole formed in the rotary output shaft is fixed, and the end of the male screw member is fixed. A portion is movably inserted into the cylinder, and a pin protruding from the cylinder is inserted into a long hole of the cylinder so as to be movable in the longitudinal direction of the long hole.

JP2009-168097 JP2008-44088

However, in such a prior art, in order to allow the pin to move in the longitudinal direction of the long hole in the long hole, the diameter of the pin has to be slightly smaller than the width of the long hole.
For this reason, the difference between the width of the long hole and the diameter of the pin becomes unstable, and the male screw member cannot be linearly moved in units of μm, for example, in proportion to the rotation of the rotation output shaft.
The present invention has been devised in view of the above circumstances, and an object of the present invention is to convert a rotary motion that can linearly move the male screw member into a linear motion without rattling in proportion to the rotation of the rotation output shaft. It is to provide a motion mechanism to perform.

  In order to achieve the above-mentioned object, the motion mechanism for converting the rotational motion of the present invention into a linear motion includes a holder attached to the rotary output shaft, and facing each other across the axis of the rotary output shaft and spaced from the axis. Supported by a pair of guide members supported by the holder so as to be movable in the approaching direction, a biasing member that biases the pair of guide members in a direction approaching each other, and a frame that supports the rotation output shaft, A female screw member having a female screw positioned coaxially with the rotary output shaft; and a male screw member having a male screw threadedly engaged with the female screw, the male screw member penetrating in a radial direction of the male screw member. A male screw member rotation pin is provided, and both ends of the male screw member rotation pin protruding from the male screw member are movable in the axial direction of the rotation output shaft by the pair of guide members, and a pair Characterized in that it is the guide member integrally rotatably clamped.

  In the present invention, the pair of guide members sandwich the male screw member rotation pin so that the male screw member rotation pin is movable and rotates integrally with the rotation output shaft at any position in the axial direction of the rotation output shaft. Therefore, there is no problem of rattling between the rotation output shaft and the male screw member, and the male screw member performs linear motion while rotating at the same phase as the rotation output shaft.

It is explanatory drawing of the movement mechanism in the state where the male screw member was most immersed, (A) is a sectional front view of the movement mechanism, (B) is a sectional plan view of the movement mechanism. It is explanatory drawing of the exercise | movement mechanism in the state which the external thread member protruded most, (A) is a cross-sectional front view of an exercise | movement mechanism, (B) is a cross-sectional top view of an exercise | movement mechanism. It is explanatory drawing of a holder, (A) is a top view, (B) is a front view, (C) is a side view. It is explanatory drawing of a leaf | plate spring, (A) is a top view, (B) is a side view. It is explanatory drawing of a guide member, (A) is a top view, (B) is a front view, (C) is a side view. It is explanatory drawing of the state in which the external thread member screwed to the internal thread, (A) is a front view, (B) is a left side view, (C) is a right side view. It is explanatory drawing of a 1st supporting member, (A) is a cross-sectional front view, (B) is a left view, (C) is a right view. It is explanatory drawing of a 2nd supporting member, (A) is a cross-sectional front view, (B) is a left view.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the motion mechanism 10 that converts rotational motion into linear motion includes a rotational output shaft 12, a holder 14, a pair of guide members 16, a biasing member 18, and a female screw member 20. The male screw member 22 and the male screw member rotating pin 24 are included.

  The rotation output shaft 12 is an output shaft of an actuator 26 such as a motor.

The holder 14 is attached to the rotation output shaft 12 so as to rotate integrally with the rotation output shaft 12.
In the present embodiment, the rotation output shaft 12 is inserted into the center hole 1402 of the holder 14, and the holder 14 is attached to the rotation output shaft 12 by pressing the rotation output shaft 12 with a screw 1404.
As shown in FIG. 3, the holder 14 is formed with a screw hole 1406 into which the screw 1404 is screwed, and a pair of leaf spring attachment surfaces 1408 that are opposed to each other with the center hole 1402 interposed therebetween. A screw hole 1410 is formed in 1408.
The dimension W1 between the ends of the pair of leaf spring mounting surfaces 1408 disposed on the motor side in the axial direction of the center hole 1402 is between the ends of the pair of leaf spring mounting surfaces 1408 disposed on the side away from the actuator 26. It is formed larger than the dimension W2.

The urging member 18 is composed of a pair of leaf springs 18 in the present embodiment.
The pair of leaf springs 18 are respectively attached to the leaf spring mounting surface 1408 via screws 1802 and screw holes 1410 and face each other with the axis of the rotation output shaft 12 in between.
Then, due to the difference between the dimension W1 and the dimension W2 between the ends of the pair of leaf spring mounting surfaces 1408, the pair of leaf springs 18 are attached so as to be gradually inclined toward each other as they move away from the rotation output shaft 12. ing.
As shown in FIG. 4, the leaf spring 18 has an elongated rectangular shape, and is formed with two screw insertion holes 1804 for inserting screws 1802 at one end in the longitudinal direction at intervals in the width direction. Two screw insertion holes 1806 for attaching the guide member 16 at intervals in the longitudinal direction are formed.

As shown in FIG. 5, the pair of guide members 16 includes an elongated rectangular central plate portion 1602 and protruding plate portions 1604 that stand up from both sides in the width direction of the central plate portion 1602, and the central plate portion 1602. A concave portion 1606 is formed inside the protruding plate portions 1604 on both sides, and a screw hole 1608 is formed in the central plate portion 1602.
The pair of guide members 16 are connected to the leaf spring 18 so that the recesses 1606 face each other.
That is, the surface of the central plate portion 1602 opposite to the concave portion 1606 is fitted to the leaf spring 18, and the screw 1610 inserted into the screw insertion hole 1806 is screwed into the screw hole 1608, whereby the pair of guide members 16 is paired with the pair of plates The spring 18 is connected.
In this state, the pair of guide members 16 are opposed to each other across the axis of the rotation output shaft 12 while being connected to the pair of leaf springs 18.
The pair of guide members 16 are attached by a pair of leaf springs 18 so as to incline toward each other gradually as they move away from the rotation output shaft 12.
The male screw member 22 is accommodated in the recess 1606 without contacting the guide member 16, and both ends of the male screw member rotation pin 24 are between the tips (tip end surfaces) 1604 A of the protruding plate portions 1604 on both sides of the pair of guide members 16. By being sandwiched, the pair of guide members 16 are coupled so as to be movable in the axial direction of the rotation output shaft 12 and to rotate integrally with the male screw member rotation pin 24.
The pair of guide members 16 are arranged so as to be gradually inclined toward each other as they move away from the rotation output shaft 12, so that the male screw member rotation pin 24 is located at any position in the axial direction of the rotation output shaft 12. The male screw member rotating pin 24 is supported so as to be movable and rotate integrally with the male screw member rotating pin 24. In this case, when the male screw member rotation pin 24 is located on the rotation output shaft 12 side, the spring force is large although the amount of bending of the pair of leaf springs 18 is small, and the male screw member rotation pin 24 is the female screw member 20. In the case where the pair of leaf springs 18 are located on the side, the spring force of the pair of leaf springs 18 is large, but the spring force is small. It is pinched by. In the present embodiment, the pair of guide members 16 are supported by the holder 14 via the leaf spring 18 so as to be opposed to each other across the axis of the rotation output shaft 12 and move away from and close to the axis. Will be.

The female screw member 20 has a female screw 20 </ b> A positioned coaxially with the rotation output shaft 12, and is supported by a frame that supports the rotation output shaft 12.
Here, the frame that supports the rotation output shaft 12 may be, for example, a housing of the actuator 26 or a base that supports the actuator 26.
As shown in FIG. 6, the female screw 20 </ b> A is a pressurized ball screw that removes backlash in the present embodiment, and uses a commercially available ball screw unit. And a flange 2004 provided at an end portion in the longitudinal direction of the portion 2002, and a screw insertion hole 2006 is formed in the flange 2004.

As shown in FIGS. 1 and 2, the female screw member 20 is supported by a frame that supports the rotation output shaft 12 via a first support member 30 and a second support member 32.
As shown in FIG. 7, the first support member 30 has a cylindrical shape, and the first support member 30 is arranged in the axial direction thereof, the mounting hole 3002 of the female screw member 20, the pair of leaf springs 18, and the pair of pairs. An accommodation hole 3004 for accommodating the guide member 16 is provided.
Further, a screw hole 3006 is formed on the end surface of the first support member 30 on the hole 3002 side, and a screw hole 3008 is formed on the end surface of the accommodation hole 3004 side.
In the female screw member 20, the cylindrical portion 2002 is inserted into the mounting hole 3002, the flange 2004 is applied to the end surface of the first support member 30 on the hole 3002 side, and a screw (not shown) inserted through the screw insertion hole 2006 is a screw. The first support member 30 is attached by being screwed into the hole 3006.
As shown in FIG. 8, the second support member 32 has an annular plate shape in which a hole 3202 for receiving the holder 14 and the pair of plate springs 18 is formed in the center thereof. A screw insertion hole 3204 and a counterbore 3206 provided coaxially with the screw hole 3008 are formed.
The second support member 32 is attached to the first support member 30 by screwing the screw inserted into the screw insertion hole 3204 into the screw hole 3008.
The second support member 32 is attached to, for example, the housing of the actuator 26 or a base that supports the actuator 26 via a counterbore 3206.

The male screw member 22 is disposed coaxially with the rotary output shaft 12 and is screwed into the female screw 20A.
As shown in FIG. 6, the male screw member 22 has a male screw portion 22 </ b> A that engages with the female screw 20 </ b> A over substantially the entire length in the longitudinal direction, and the tip portion of the male screw member 22 is formed in a spherical shape.
A hole 2202 is formed through the base end of the male screw member 22 in a direction perpendicular to the longitudinal direction of the male screw member 22.

The male screw member rotation pin 24 is press-fitted into the hole 2202, and both ends of the male screw member rotation pin 24 protrude in the direction perpendicular to the longitudinal direction of the male screw member 22 at the base end of the male screw member 22.
The male screw member 22 is accommodated in the recess 1606 without contacting the guide member 16, and both ends of the male screw member rotating pin 24 are movable between the tips 1604 A of the protruding plate portions 1604 on both sides of the pair of guide members 16. And it is clamped so as to rotate integrally with the male screw member rotation pin 24.

According to the present embodiment, when the rotation output shaft 12 rotates, the holder 14, the pair of leaf springs 18, and the pair of guide members 16 are rotated and sandwiched between the tips 1604 </ b> A of the protruding plate portions 1604 of the pair of guide members 16. The male screw member 22 is rotated integrally with the rotary output shaft 12 through the male screw member rotation pin 24 thus formed.
The pair of guide members 16 includes a male screw member rotation pin 24 so that the male screw member rotation pin 24 can move and rotate integrally with the rotation output shaft 12 at any position in the axial direction of the rotation output shaft 12. Is held by the spring force having substantially the same value, so that the problem of rattling between the rotation output shaft 12 and the male screw member 22 does not occur, and the male screw member 22 rotates at the same phase as the rotation output shaft 12. While doing a linear motion. Specifically, when the rotation output shaft 12 rotates forward or reverse, the male screw member 22 performs a reciprocating linear motion while rotating forward and backward at the same phase as the rotation output shaft 12. Therefore, it is possible to linearly move, for example, in units of μm without causing the male screw member 22 to swing in proportion to the rotation of the rotation output shaft 12.
Further, in the present embodiment, the pair of leaf springs 18 and the pair of guide members 16 that are rotated by the rotation output shaft 12 are small and lightweight. Therefore, the motion mechanism that converts the rotational motion into the linear motion is downsized. This is advantageous in reducing the weight.
In the present embodiment, the female screw 20A is a pressurized ball screw that removes backlash, and is therefore more advantageous when the male screw member 22 is linearly moved in units of μm in proportion to the rotation of the rotary output shaft 12, for example. For example, it is suitable for use in a micrometer head.

  DESCRIPTION OF SYMBOLS 10 ... Movement mechanism, 12 ... Rotation output shaft, 14 ... Holder, 16 ... Guide member, 18 ... Biasing member, 20 ... Female screw member, 22 ... Male screw member, 24 ... Male screw member rotation pin.

Claims (3)

A holder attached to the rotary output shaft;
A pair of guide members supported by the holder so as to be opposed to each other across the axis of the rotation output shaft and move away from and close to the axis;
A biasing member that biases the pair of guide members in a direction approaching each other;
A female screw member having a female screw that is supported by a frame that supports the rotary output shaft and is coaxially positioned with the rotary output shaft;
A male screw member formed with a male screw threadedly engaged with the female screw;
The male screw member is provided with a male screw member rotation pin penetrating in the radial direction of the male screw member,
Both ends of the male screw member rotation pin protruding from the male screw member are clamped by the pair of guide members so as to be movable in the axial direction of the rotation output shaft and integrally rotated with the pair of guide members.
A motion mechanism that converts rotational motion into linear motion. The biasing member is composed of a pair of leaf springs attached to the holder and facing each other across the axis of the rotation output shaft and gradually approaching each other as the distance from the rotation output shaft increases.
The pair of guide members include a rectangular central plate portion that is elongated in the axial direction, and protruding plate portions that stand up from both sides in the width direction of the central plate portion, and the central plate portion and the protruding plates on both sides A recess is formed inside the part,
The pair of guide members are connected to the leaf spring so that the concave portions face each other,
The male screw member is housed in the recess of the pair of guide members,
The clamping by the pair of guide members at both ends of the male screw member rotating pin protruding from the male screw member is performed between the tips of the protruding plate portions on both sides of the pair of guide members.
A motion mechanism for converting the rotational motion according to claim 1 into a linear motion. The female screw is a pressurized ball screw that removes backlash,
A motion mechanism that converts the rotational motion according to claim 1 or 2 into a linear motion.

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