JP2022047754A - Micro head - Google Patents

Abstract

To provide a micro head with less backlash and shaft shake even if with a simple structure.SOLUTION: The micro head includes: a spindle with a sliding portion and a threaded portion; a sleeve with a through hole through the axial direction of the spindle; a thimble that can rotate around the sleeve as a rotation axis and is partially connected to one end of the spindle; and a backlash absorbing member that is fixed to the sleeve in the sleeve at a position facing the threaded portion of the spindle and includes a metal screw member and a resin screw member. The sleeve has a stepped portion in the middle of the through hole that directly or indirectly contacts the backlash absorbing member.SELECTED DRAWING: Figure 1

Description

The present invention relates to a micro head.
In particular, the present invention relates to a micro head that can reduce backlash and shaft shake even with a simple mechanism.

Generally, the micro head is a feed mechanism capable of fine feed in units of several μm, and the male screw provided on the spindle and the female screw provided on the sleeve are screwed together to form a shaft. It is a structure that moves on.
Conventionally, various microheads have been proposed that reduce backlash generated between the spindle and the sleeve (spindle support cylinder), twisting applied to the spindle, and improve responsiveness and repeatability.

For example, a pressurization ring having a female thread that is screwed into the male thread of the spindle, a pressurization spring that urges the pressurization ring and the sleeve in a direction away from each other, and a pressurization spring between the pressurization ring. A micro head that reduces backlash by providing an adjusting nut so as to sandwich the backlash has been proposed (see Patent Document 1).

More specifically, the microhead illustrated in FIG. 7 has been proposed.
The microhead 100a includes a spindle support cylinder 120 having a female threaded portion formed on the inner peripheral surface thereof, and a spindle 110a having a male threaded portion screwed to the female threaded portion 121 of the spindle support cylinder 120 on the outer peripheral surface.
Further, the pressurization ring 160 having the female thread portion 161 screwed to the male thread portion of the spindle, and the pressurization ring 160 inserted between the pressurization ring 160 and the spindle support cylinder 120 on the outer periphery of the spindle, the pressurization ring 160 is attached to the spindle support cylinder 120. It is provided with a pressurization spring 170 that urges the object in a direction away from the other.
A through hole penetrating the spindle 110a in the axial direction is formed on the outer peripheral edge of the pressurizing ring 160, and the through hole is axial with respect to the engaging pin 180 connected in parallel to the spindle support cylinder 120 in the axial direction. Engaged displaceably in the direction.
Therefore, the adjusting nut 150 and the pressurizing ring 160 act as double nuts to reduce backlash.

Further, a male threaded portion having the same pitch as the male threaded portion of the spindle is formed on the outer peripheral surface of the fixed sleeve, and a female threaded portion screwed to the male threaded portion of the fixed sleeve is formed on the inner peripheral surface of the thimble. A microhead that prevents the spindle from twisting or the like has been proposed (see Patent Document 2).

More specifically, the microhead illustrated in FIG. 8 has been proposed.
8 (a) is a plan view of the micrometer 200, and FIG. 8 (b) is a cross-sectional view of the micro head 200a along the line AA in FIG. 8 (a).
The microhead 200a includes a spindle 210, a fixed sleeve 220, a thimble 230, and an operation sleeve 240. The fixing sleeve 220 includes a female screw portion 221 screwed into the male screw portion 210a of the spindle 210, and a male screw portion 223 screwed into the female screw portion 231 of the thimble 230.

In the micro head 200a, when the operation sleeve 240 is rotated, the spindle 210 moves along the axial direction thereof.
On the other hand, in the micro head 200a, when a force other than the original force, such as a twisting force or a force in the radial direction, is applied to the operation sleeve 240, this force is also transmitted to the thimble 230. However, since the thimble 230 includes a female screw portion 231 screwed into the male screw portion 223 of the fixed sleeve 220, a force other than the original force transmitted to the thimble 230 is received by the fixed sleeve 220.
Therefore, since a twisting force or a force in the radial direction is not applied to the spindle 210, it is possible to prevent the spindle from shaking.

Japanese Unexamined Patent Publication No. 2010-210556 Japanese Unexamined Patent Publication No. 2011-226839

However, in the case of the micro head disclosed in Patent Document 1, when a force exceeding the elastic force is applied due to the structure of pressing the screw groove by the pressurization spring 170 between the adjusting nut 150 and the pressurization ring 160, the spring. Was pushed back, and there was a problem that the effect of reducing backlash could not be obtained.
Further, in addition to the spindle support cylinder 120, the adjusting nut 150 and the pressurization ring 160 each need to have a screw structure, which causes a problem that the structure becomes complicated.

Further, in the case of the micro head disclosed in Patent Document 2, there is a description that a force other than the original force can be reduced by the female screw portion 231 of the thimble 230 and the fixing sleeve 220, but the backlash of the spindle 210 is described. No consideration was given.
In addition to the inside of the fixing sleeve 220, it also has a male screw portion on the outside, and by screwing it with the female screw portion 231 provided on the thimble 230, it is structurally prevented from shaft shake, so it is highly accurate for processing and assembly. There was a problem that was necessary.
Further, since backlash exists between the spindle 210 and the fixed sleeve 220 and between the fixed sleeve 220 and the thimble 230, the stress acting between the male screw portion 223 and the female screw portion 231 is weak and the lock is applied. Without the mechanism, there was a problem that the spindle 210 was unintentionally displaced due to vibration or the like.

Therefore, as a result of diligent studies, the inventor of the present invention includes a spindle, a predetermined sleeve, a thimble, and a predetermined backlash absorbing member fixed to the sleeve, even if the structure is simple. We have found that backlash and shaft shake can be reduced, and have completed the present invention.
That is, according to the present invention, it is an object of the present invention to provide a microhead capable of effectively reducing backlash and shaft shake even with a simple structure, and a stage mechanism using the same.

The present invention can rotate a spindle having a sliding portion and a threaded portion, a sleeve having a through hole along the axial direction of the spindle, and the sleeve as a rotation axis, and is partially connected to one end of the spindle. A microhead that includes a thimble and a backlash absorbing member that is secured to the sleeve at a position within the sleeve that faces the threaded portion of the spindle. The sleeve is a microhead having a stepped portion in the middle of the through hole that directly or indirectly abuts on the backlash absorbing member.
With this configuration, the backlash absorbing member can be abutted against the spindle and the backlash absorbing member can be strongly tightened.
Therefore, it is not necessary to provide a screw portion, a collar, or the like on the sleeve itself to press the backlash member, and even with a simple configuration, backlash and shaft shake can be effectively reduced.

Further, in constructing the present invention, the sleeve has an accommodating portion in which the backlash absorbing member is fitted on the thimble side of the step portion, and guides the slide of the sliding portion to the tip end side of the spindle from the step portion. When the guide portion is provided, the diameter of the accommodating portion is α mm, the diameter of the guide portion is β mm, and the diameter of the step portion is D mm, it is preferable to satisfy the following relational expression (1).
α> D ≧ β (1)
With this configuration, by adjusting the diameter of the accommodating portion, the diameter of the guide portion, and the diameter of the step portion, respectively, the backlash member is screwed to the spindle in advance to the sleeve. It becomes easy to insert, and backlash and shaft shake can be reduced more effectively.

Further, in constructing the present invention, when the sleeve has the total length of the sleeve _L (mm) and the length occupied by the guide portion is LG (mm) in the direction along the axis of the spindle, the following relationship is established. It is preferable to satisfy the formula (2).
0.3L ≤ L _G ≤ 0.9L (2)
With this configuration, the ratio of the guide portion to the spindle can be adjusted, so shaft shake can be reduced more effectively, and operability can be further improved by setting the friction suitable for operation. can.

Further, in constructing the present invention, it is preferable that the sleeve has an opening on the thimble side, which is an opening for fitting the backlash absorbing member into the accommodating portion.
With this configuration, the backlash member can be easily inserted into the sleeve in a state where the backlash member is screwed into the spindle in advance.
Further, since the backlash absorbing member can be mounted at a predetermined position in the sleeve by self-alignment, it can be assembled more easily.
Therefore, even with a simple configuration, backlash and shaft shake can be reduced more effectively.

Further, in constructing the present invention, it is preferable that the sleeve has a fixing member for preventing the backlash absorbing member from being displaced.
With such a configuration, the backlash absorbing member can be easily fixed in a state of being abutted against the step portion.
At the same time, it is possible to easily prevent the backlash absorbing member from rotating in the sleeve as the spindle rotates.
Therefore, even with a simple configuration, backlash and shaft shake can be reduced more effectively.

Further, in constructing the present invention, the backlash absorbing member has the total length of the backlash absorbing member as LB (mm) and the length occupied by the resin _screwing member as _LR (in the direction along the axis of the spindle). In the case of mm), it is preferable to satisfy the following relational expression (3).
0.05L _B ≤ L _R ≤ 0.7L _B (3)
With this configuration, the ratio of the length occupied by the resin screw member to the total length of the backlash absorbing member can be specified in the direction along the axis of the spindle, so that the backlash and the shaft can be more effectively configured. Blur can be reduced and operability can be further improved.

Further, in constructing the present invention, when the metal screwing member has two tubular members, one of the tubular members is a first tubular member and the other is a second tubular member. It is preferable that the resin screwing member is located between the first tubular member and the second tubular member.
With this configuration, the axial position of the resin screw member is fixed, so it is not necessary to provide a screw portion, collar, etc. on the sleeve itself and press the backlash member, which is a simple configuration. However, backlash and shaft shake can be effectively reduced.
Further, by sandwiching the resin screwing member between the two tubular members, the resin screwing member can be screwed to the spindle while applying a certain force, so that the assembly can be facilitated.

Further, in constructing the present invention, it is preferable that the metal screwing member includes a resin ring as a resin screwing member.
With such a configuration, it becomes easy to adjust the degree of stress applied to the resin screwed member, and the operability can be further improved.
In addition, since the resin screw member can be protected from an external impact, assembly can be made easier, and even with a simple structure, backlash and shaft shake can be reduced more effectively.

1 (a) is a perspective view of the microhead of the first embodiment, and FIG. 1 (b) is cut along the line AA in FIG. 1 (a) and along the arrow. It is sectional drawing of the micro head when viewed from a direction. 2 (a) to 2 (c) are views provided for explaining a configuration example of the sleeve. FIG. 3A is an exploded perspective view of a case where a resin screwing member is provided between metal tubular members as a backlash absorbing member, and FIG. 3B is a backlash absorbing member. It is an exploded perspective view of the case where one of the metal tubular members is used as a metal protective cover including a resin ring as a resin screwing member. 4A is an enlarged cross-sectional view of the backlash absorbing member shown in FIG. 3A, and FIG. 4B is an enlarged cross-sectional view of the backlash absorbing member shown in FIG. 3B. be. 5 (a) is a perspective view showing a stage mechanism which is an example of using the micro head of the second embodiment, FIG. 5 (b) is a side view of the stage mechanism, and FIG. 5 (c). Is a partial cross-sectional view illustrating the main part Q of the second connection part. FIG. 6A is an exploded perspective view focusing on the guide rail structure of the stage mechanism, and FIG. 6B is a cut along the line BB of FIG. 6A and along the arrow. It is a cross-sectional view when viewed from a direction, and FIG. 6 (c) is a cross-sectional view of another guide rail structure. FIG. 7 is a cross-sectional view of a conventional microhead. 8 (a) is a plan view of a conventional micro head, and FIG. 8 (b) is a cross-sectional view of another conventional micro head.

Hereinafter, embodiments of the microhead of the present invention and a stage mechanism using the same will be described with reference to the drawings.
Further, in each of the figures used for the description, the same components may be designated with the same reference numerals and the description thereof may be omitted.
Each figure used in the description is shown schematically to the extent that the present invention can be understood, and the shapes, dimensions, materials and the like described in the following description are merely suitable examples within the scope of the present invention. Therefore, the present invention is not limited to the following embodiments.

[First Embodiment]
In the first embodiment, as shown in FIG. 1, a spindle 11 having a sliding portion 11a and a threaded portion 11b, a sleeve 13 having a through hole, and a thimble 15 partially connected to one end of the spindle 11 And a backlash absorbing member 17 including a metal screwing member 18b and a resin screwing member 18c.
Further, the sleeve 13 is a microhead 10 characterized by having a stepped portion 13c that directly or indirectly abuts on the backlash absorbing member 17 in the middle of the through hole.
Hereinafter, the details of each component and their mutual relationship will be described.

1. 1. Spindle The spindle 11 transfers a member screwed to the spindle in the axial direction (hereinafter, may be referred to as the axial direction) of the spindle 11 indicated by reference numeral S1 in FIG. ₁ (b) by rotating the spindle 11. It is a columnar member for this purpose, and is a member having a sliding portion 11a and a screw portion 11b at a desired portion along the axial direction thereof.
The ratio between the length of the sliding portion 11a and the length of the screw portion 11b can be determined according to the design of the microhead, but the screw portion 11b needs a portion to be screwed into the backlash absorbing member described later. It is preferable that it is longer than the sliding portion 11a.
That is, the ratio of the sliding portion 11a to the screw portion 11b is usually 1: 1 to 1 so that the ease of sliding, the stability of the screw feed, and the backlash absorption effect described later can be effectively obtained. : It is preferable that the value is within the range of 3.
Further, it is preferable that the diameter of the sliding portion 11a of the spindle 11 is equal to or larger than the diameter of the threaded portion 11b of the spindle 11. The reason for this is that there are advantages such as easy insertion into the sleeve 13.

Further, the spindle 11 is preferably made of a metal material from the viewpoint of strength and workability. Examples of such metal materials include stainless steel, high carbon chrome bearing steel, alloy tool steel, cast iron, carbon steel and steel materials.
Specific examples of stainless steel include SUS304 and, for example, stainless steel specified in JIS G4303.
Specific examples of the high carbon chrome bearing steel include SUJ2, SUJ3, SUJ4, SUJ5 and the like specified in JIS G4805.
Specific examples of the alloy tool steel include SKS material, SK material, SKD material, SKT material and the like specified in JIS G4404.
Specific examples of cast iron include so-called ordinary cast iron, alloy cast iron and the like.
Specific examples of the carbon steel material include SC45C and the like.
In this embodiment, the spindle 11 is made of high carbon chromium bearing steel, but is not limited to this. This material is more preferable because it has excellent physical properties such as Brinell hardness and is excellent in compatibility with other members in terms of thermal expansion coefficient and the like.

2. 2. Sleeve (1) Main configuration The sleeve 13 is a member into which the spindle 11 is incorporated, and is screwed to the spindle 11 via a backlash absorbing member 17 provided inside, which serves as a bearing. Is.
Further, as the main configuration, the sleeve 13 has a through hole along the axial direction of the spindle 11, and has a predetermined step portion 13c described later in the middle of the through hole.
Here, the material of the sleeve 13 is preferably made of a metal material from the viewpoint of strength and workability. Examples of such metal materials include stainless steel, carbon tool steel, alloy tool steel, chrome steel, manganese steel, carbon steel and the like. In this embodiment, the sleeve 13 is made of S45C, which is a kind of carbon steel material. This material is more preferable because it has excellent physical properties such as Brinell hardness and is excellent in compatibility with other members in terms of thermal expansion coefficient and the like.

(2) Stepped portion The stepped portion 13c is a portion for strongly tightening the backlash absorbing member 17 against the spindle 11 by abutting the backlash absorbing member 17.
This is because the corner portion of the backlash absorbing member 17 is abutted against the step portion 13c, and the stress acts on the spindle 11 in a direction slightly inclined toward the inside of the spindle 11 with respect to the axial direction. On the other hand, it is considered that the force for tightening the backlash absorbing member 17 is improved.
Further, the step portion 13c is provided in the middle of the through hole of the sleeve 13 and is a portion that directly or indirectly abuts on the backlash absorbing member.
Here, the middle of the through hole indicates a position having a region of the backlash absorbing member 17 longer than the axial length of the spindle 11 on the opposite side of the backlash absorbing member 17 via the step portion 13c. ..
Further, the case of indirectly contacting the backlash absorbing member 17 is, for example, a flat washer for improving the stability of the contact surface between the backlash absorbing member 17 and the stepped portion 13c, or the backlash absorbing member 17. The case where the contact is made through a detent washer or the like for preventing the rotation of the is shown.

Further, for example, after making a through hole in the sleeve 13, the step portion 13c is countersunk from the thimble 15 side with a diameter of D mm, leaving the length of the guide portion 13b described later, and further on the thimble 15 side. Therefore, it can be formed by inserting a counterbore having a diameter α as the accommodating portion 13a described later with the length of the accommodating portion 13a described later.
At this time, when the diameter β and the diameter D of the guide portion 13b described later are the same, after making a through hole of the diameter β (D) in the sleeve 13, the length of the accommodating portion 13a is reached from the thimble 15 side. Now, the stepped portion 13c can be formed only by inserting a counterbore having a diameter α.

Further, the height H of the step portion 13c is a value determined by the diameter α and the diameter D of the accommodating portion 13a described later, and is a value obtained by (α−D) / 2.
Here, the diameter D may be larger than the diameter of the spindle 11, but considering the case of direct contact with the backlash absorbing member 17, α / 4 ≦ from the viewpoint of ensuring a stable abutting height H. It is preferable to satisfy the relationship of D ≦ 3α / 4.

Further, the step portion 13c preferably has a chamfered tapered portion.
The reason for this is that the stepped portion 13c has a predetermined tapered portion, so that when the backlash absorbing member 17 is abutted, the backlash absorbing member 17 is strongly tightened against the spindle 11. This is because it can be done easily.
That is, the angle formed by the step portion 13c with the contact surface with respect to the backlash absorbing member 17 (hereinafter, may be referred to as the angle of the tapered portion of the step portion 13c) is 0, where the case perpendicular to the axial direction is 0 °. A value exceeding ° is preferable, a value exceeding 5 ° is preferable, and a value exceeding 10 ° is further preferable.
Further, the angle of the tapered portion of the step portion 13c is preferably 45 ° or less, more preferably 40 ° or less, and further preferably 30 ° or less.
The specific size of the tapered portion of the stepped portion 13c is preferably H / 5 or more in the height H direction of the stepped portion 13c, and more preferably H / 3 or more. It is preferable that the height H of the step portion 13c is the same as that of the height H.

(3) Accommodating part, guide part (3) -1 Configuration The sleeve 13 has a through hole and has a stepped portion 13c in the middle, and backlash absorption is performed on the thimble 15 side of the stepped portion 13c. It is preferable to have an accommodating portion 13a into which the member 17 is fitted, and a guide portion 13b for guiding the slide of the sliding portion on the tip end side of the spindle with respect to the step portion 13c.
The reason for this is that by forming the accommodating portion 13a that matches the size of the backlash absorbing member 17 on the sleeve 13, it can be mounted in a predetermined position by self-alignment.
Further, by forming the guide portion 13b corresponding to the diameter of the sliding portion 11a on the sleeve 13, it is more effective even if a member for preventing shaft shake such as a collar is substantially not provided. This is because the shaft shake can be reduced.

Further, the accommodating portion 13a has a length _LA mm (see FIG. 1) that is about the same as the total length LB mm (see FIG. 4) of the backlash absorbing member 17 provided from the thimble 15 _side to the tip end side of the spindle 11. ), A portion having a diameter of α mm.
The guide portion 13b has a length of _LG mm (see FIG. 1) provided on the tip end side of the spindle 11 in the sleeve 13, and has a diameter β mm larger than that of the sliding portion 11a by a predetermined tolerance. It is a part.
Here, the diameter α, the diameter β, and the diameter D may be values according to the size of the equipment using the microhead 10, but it is preferable that the following relational expression (1) is satisfied.
α> D ≧ β (1)
The reason for this is that by making such a relationship, the spindle 11 can be inserted from the thimble 15 side with the backlash absorbing member 17 screwed into the sleeve 13, and the backlash can be more effectively inserted. This is because it is possible to reduce.
Further, the specific diameter α of the accommodating portion 13a is preferably a value in the range of 6 to 200 mm, more preferably a value in the range of 8 to 100 mm, and in the range of 10 to 30 mm. It is more preferable to have.
The specific diameter β of the guide portion 13b is preferably a value in the range of 4 to 180 mm, more preferably a value in the range of 6 to 80 mm, and a value in the range of 8 to 20 mm. It is more preferably a value.
The reason for this is that by setting the value within this range, the target microhead can be easily manufactured by a commonly used drill or cutting blade.

(3) -2 The length of the guide part _LG
Further, the length LG of the guide portion _13b is selected so as not to hinder the rotation and sliding of the spindle 11 so that the shaft shake prevention effect can be obtained.
Specifically, the predetermined length _LG preferably satisfies the following relational expression (2) when the total length of the sleeve 13 is expressed as L.
0.3L ≤ L _G ≤ 0.9L (2)
The reason for this is that by setting the value within such a range, the spindle 11 can be slid more effectively, smoothly and without shaft shake, substantially without providing a shaft shake prevention member such as a collar. Is.
Therefore, it is more preferable that the predetermined length LG of the guide portion 13b satisfies 0.4L ≦ _LG ≦ 0.8L, and further preferably _0.5L ≦ _LA ≦ 0.7L.

(3) -3 Length of accommodating part _LA
Further, the length _LA of the accommodating portion 13a is selected so that it can come into contact with the threaded portion 11b of the spindle 11 so that the backlash absorbing effect can be obtained, and the slidability of the spindle can also be obtained.
Specifically, it is preferable that the predetermined length _LA satisfies the following relational expression (2-2) when the total length of the sleeve 13 is expressed as L.
_0.1L ≤ LA ≤ _0.5L (However, LA + _LG ≤ L) (2-2)
The reason for this is that the through hole 12a of the sleeve 13 according to the present invention includes a predetermined accommodating portion 13a, so that when the backlash absorbing member 17 is inserted into the sleeve 13 from the end of the sleeve 13 on the thimble 15 side, This is because the backlash absorbing member 17 can be mounted in a predetermined position (that is, the accommodating portion 13a) in the sleeve 13 by self-alignment. Therefore, the target microhead 10 can be easily manufactured.
Therefore, it is more preferable that the predetermined length LA of the accommodating portion 13a satisfies _0.15L ≦ LA ≦ _0.45L , and further preferably 0.2L ≦ LA ≦ _0.4L .
Here, the total length L of the specific sleeve 13 is preferably a value in the range of 30 to 300 mm, more preferably a value in the range of 40 to 150 mm, and a value in the range of 50 to 100 mm. It is more preferably a value.
The reason for this is that by setting the value within such a range, when the sleeve 13 is provided with the counterbore as the accommodating portion 13a, the target microhead 10 can be manufactured more accurately even with a general processing machine. Because it can be done.

(4) Fixing member The sleeve 13 preferably includes a fixing member 17d that prevents the backlash from being displaced.
The reason for this is that the fixing member 17d is inserted into the backlash absorbing member 17 via a screw hole or a pin hole provided in the sleeve 13 to fix the axial position of the backlash absorbing member 17. This is because it can be done easily. At the same time, it is easier to prevent the backlash absorbing member 17 from rotating together with the spindle 11.
That is, it is possible to reduce backlash and shaft shake with a simpler configuration.
As a specific fixing member 17d, with the backlash absorbing member 17 adhered to the sleeve 13, a pin hole is later provided on the peripheral surface of the sleeve 13 together with the backlash absorbing member 17, and the pin hole is provided. There is a set pin to be driven into.
Further, there is a set screw in which a screw hole is provided on the peripheral surface of the sleeve 13 together with the backlash absorbing member 17 in a state where the backlash absorbing member 17 is adhered, and the screw hole is embedded in the screw hole.
The backlash absorbing member 17 is not adhered to the sleeve 13, but a pin hole is formed in advance, and the backlash absorbing member 17 is aligned with the pin hole and the screw hole provided on the peripheral surface of the sleeve 13 with the fixing member 17d. It is also preferable to fix it.
The reason for this is that the backlash absorbing member 17 can be attached and detached so that adjustment, parts replacement, and the like can be performed more easily.

(5) Opening The sleeve 13 preferably has an opening on the thimble 15 side, which serves as a fitting port for the backlash absorbing member 17 into the accommodating portion 13a.
The reason for this is that the backlash absorbing member 17 is screwed into the spindle 11 in advance, and the spindle 11 is inserted into the through hole 12a in that state, so that the backlash absorbing member 17 is arranged in the accommodating portion 13a. This is because it can be assembled more easily.
Further, by screwing the metal screwing member 18b and the resin screwing member 18c as the backlash absorbing member 17 in a state where stress is applied in advance, the degree of stress applied to the resin screwing member can be adjusted. This is because it becomes easier and the backlash can be reduced more effectively.

(6) Example of sleeve configuration As a first configuration example of the sleeve 13, as shown in FIG. 2A, the diameter β of the guide portion 13b is made the same as the diameter D of the step portion, and the accommodating portion 13a is provided. An example (α> D = β) smaller than the diameter α can be mentioned.
With such a configuration, the diameter D of the stepped portion is automatically determined only by determining the diameters of the accommodating portion 13a and the guide portion 13b, so that the stepped portion 13c can be formed more easily and more. It is preferable because it can have a simple configuration. Further, by setting the diameter α> the diameter β, it is easier to insert the spindle 11 from the thimble 15 side with the backlash absorbing member 17 screwed.

Further, as a second configuration example of the sleeve 13, as shown in FIG. 2B, the diameter β of the guide portion 13b is made smaller than the diameter D of the stepped portion, and is smaller than the diameter α of the accommodating portion 13a. An enlarged example (α>D> β) can be mentioned.
With such a configuration, as in the first configuration example, the diameter α> the diameter β, and it is easier to insert the spindle 11 from the thimble 15 side with the backlash absorbing member 17 screwed. can.
Further, since the diameter D> the diameter β, a micro head having a tip smaller than the diameter of the threaded portion of the spindle 11 can be configured.

Further, as a configuration example 3 of the sleeve 13, as shown in FIG. 2C, the diameter β of the guide portion 13b is made smaller than the diameter D of the step portion and larger than the diameter α of the accommodating portion 13a. An example (β>α> D) is given.
With such a configuration, a microhead having a tip thicker than the diameter of the threaded portion of the spindle 11 can be configured, and can be adapted to the intended use.

3. 3. Thimble Thimble 15 is a cylindrical member having an opening at one end. The thimble 15 is a member in which a part of the sleeve 13 is inserted from the opening side with a predetermined fitting condition and is rotatable with respect to the sleeve 13 with the sleeve 13 as a rotation axis.
Moreover, the thimble 15 is a member connected to one end of the spindle 11 at the end surface opposite to the opening into which the sleeve 13 is inserted. Specifically, in the case of this embodiment, the end portion of the thimble 15 opposite to the opening is fixed to one end surface of the spindle 11 by a screw 15a. Therefore, the microhead 10 has a structure in which the spindle 11 and the thimble 15 are directly connected.

Further, in order to indicate the degree of rotation from an arbitrary position, a predetermined sub-scale 15b (see FIG. 1A) is provided at the end portion of the thimble 15 on the opening side along the outer periphery.
Further, the end portion of the thimble 15 of this embodiment opposite to the opening portion has a larger diameter than the other portions, and the outer peripheral surface of the portion having the larger diameter is knurled to be an operation knob. It is set as 15c. This is to improve the operability of the micro head 10.
The thimble 15 is preferably made of a metal material from the viewpoint of strength and workability. Examples of such metal materials include stainless steel, aluminum, carbon tool steel, alloy tool steel, chrome steel, manganese steel and the like. In this embodiment, the thimble 15 is made of alloy tool steel (SKT6). This material is more preferable because it has excellent physical properties such as Brinell hardness and is excellent in compatibility with other members in terms of thermal expansion coefficient and the like.

4. Backlash absorbing member (1) Basic configuration The backlash absorbing member 17 is a member for reducing backlash in a screwed portion with the spindle 11, and includes a metal screwing member 18b and a resin screwing member 18c. It is a member fixed to the sleeve at a position in the sleeve 13 facing the threaded portion of the spindle.
Further, when the total length of the backlash absorbing member 17 is LB (mm) and the length occupied by the resin screwing member _{18c is LR (} mm), it is preferable that the following relational expression (3) is satisfied. ..
0.05L _B ≤ L _R ≤ 0.7L _B (3)
The reason for this is that by defining the ratio of the resin screwing member 18c to the entire backlash absorbing member 17, the effect of reducing backlash and shaft shake is maintained, and the spindle is less likely to be caught during rotation. This is because it can be set to a state.
Therefore, the length L _R is more preferably a value within the range of 0.1 L _B ≤ L _R ≤ 0.5 L _B , and a value within the range of 0.15 L _B ≤ L _R ≤ 0.3 L _B. It is more preferable to have.
Here, the total length _LB of the specific backlash absorbing member 17 is preferably a value in the range of 3 to 150 mm, more preferably a value in the range of 4 to 75 mm, and 5 to 50 mm. It is more preferable that the value is within the range of.
The reason for this is that by setting the value within such a range, the target microhead 10 can be easily manufactured according to the pitch width of 0.4 to 2 mm, which is a generally used spindle 11.

Further, it is preferable that the backlash absorbing member 17 has a chamfered tapered portion at a corner on the side that directly or indirectly abuts on the step portion 13c.
The reason is that the backlash absorbing member 17 has a predetermined tapered portion, so that it is easier to strongly tighten the backlash absorbing member 17 against the spindle 11 when the backlash absorbing member 17 abuts against the stepped portion 13c. Because it can be done.
That is, the angle formed by the contact surface of the backlash absorbing member 17 with respect to the step portion 13c is defined as 0 ° when it is perpendicular to the axial direction (hereinafter, it may be referred to as an angle of the tapered portion of the backlash absorbing member 17). Is preferably a value exceeding 0 °, preferably a value exceeding 5 °, and further preferably a value exceeding 10 °.
Further, the angle of the tapered portion of the backlash absorbing member 17 is preferably 45 ° or less, more preferably 40 ° or less, and further preferably 30 ° or less.

(2) Metal screwing member The metal screwing member 18b is screwed with the spindle 11 and the resin screwing member 18c described later is directly or indirectly pressed against the stepped portion 13c to position the resin screwing member 18c. It is a member for further enhancing the effect of reducing backlash by generating stress in the resin screwing member 18c while fixing the metal.
Specifically, the metal screwing member 18b is a member having a female threaded portion corresponding to the threaded portion 11b of the spindle 11, and examples thereof include an aluminum alloy and a stainless steel nut.

(3) Resin screwing member The resin screwing member 18c is directly or indirectly pressed against the step portion 13c by the metal screwing member 18b, and has an effect of reducing backlash between the resin screwing member and the threaded portion of the spindle 11. It is a member that exerts.
Specifically, the material of the resin screwing member 18c is, for example, an amide resin (nylon resin), a urethane resin, an ester resin, a carbonate resin, an acrylic resin, an olefin resin, and a rubber resin (natural rubber, styrene rubber, butadiene rubber). , Styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), etc.), imide resin, amido-imide resin, phenoxy resin, polyether sulfone It is preferably composed of at least one of a resin, a polyether ether ketone resin, a silicone resin, an epoxy resin, a cyanate resin, a guanamine resin, a urea resin, and a phenol resin.
The reason for this is that such a thermoplastic resin material or a thermosetting resin material has improved moldability, backlash absorbency, etc., and further excellent mobility and fixability of the spindle 11 can be obtained. be.
In particular, if it is at least one of an amide resin (nylon resin), a urethane resin, and a rubber-based resin, the balance between the mobility and the fixing property of the spindle 11 is further good, and the durability and the like are also improved. It is more preferable because it is excellent.

(4) Space portion Further, it is preferable that the backlash absorbing member 17 has a space portion 18d in a region surrounded by the spindle 11, the resin screwing member 18c, and the metal screwing member 18b.
The reason for this is that when grease or the like as a lubricant is applied to the spindle 11 in order to improve the slidability of the spindle 11, the spindle 11 is rotated to form a resin pool in the space 18d. Because it can be done.
By doing so, it is possible to prevent the grease from being dispersed and consumed all at once, and to gradually improve the slidability in the long term by supplying the grease little by little from the resin pool.
Further, by having a non-screwed space portion 18d between the resin screwing member 18c and the metal screwing member 18b, when the metal screwing member 18b is pressed against the resin screwing member 18c, the spindle 11 This is because it is less likely to be disturbed by the screw portion 11b of the above, and stress can be applied more effectively.
By doing so, the effect of the double nut works more effectively between the resin screwing member 18c and the metal screwing member 18b, and backlash and shaft shake can be more easily reduced.

(5) Configuration Example of Backlash Absorbing Member Here, two examples will be described. That is, it is an example in the case where two metal tubular members and a backlash absorbing member 17 including the resin screwing member 18c are used as the metal screwing member 18b, and the arrangement of the resin screwing member 18c is set respectively. Two examples that have changed.
In the first example, as shown in FIGS. 3 (a) and 4 (a), a first cylindrical member 17a made of metal having a female screw portion corresponding to the screw of the spindle 11 and a screw of the spindle are used. A resin having a through hole of a predetermined diameter, which is arranged between a metal second cylindrical member 17b having a corresponding female thread portion and these first tubular member 17a and the second tubular member 17b, and through which the spindle 11 can penetrate. This is an example in which a resin member 17c as a screwing member 18c and a backlash absorbing member 17x provided with the resin member 17c are used.
The first cylindrical member 17a, the resin member 17c, and the second tubular member 17b are fitted into the accommodating portion 13a of the sleeve 13, and in this example, the second tubular member 17b is attached to the sleeve 13. It is fixed by a fixing member 17d.
Therefore, the first cylindrical member 17a, the resin member 17c, and the second tubular member 17b can be fixed to the accommodating portion 13a of the sleeve 13 in a constant state. In addition, in order to increase the certainty of fixing, in addition to the fixing by the fixing member 17d, or instead of the fixing by the fixing member 17d, the first tubular member 17a, the resin member 17c, and the second tubular member 17b are used. It is also preferable to fix the sleeve 13 to the accommodating portion 13a with an adhesive.

When fixing with an adhesive, it is preferable to use an anaerobic adhesive or a cyanoacrylate-based instant adhesive that cures in response to moisture in the air.
If an anaerobic adhesive is used, the first tubular member 17a, the resin member 17c, and the second tubular member 17b are fitted into the accommodating portion 13a of the sleeve 13, and then adhered without heating or light irradiation. This is because the desired adhesion can be achieved by placing the object in an air-blocking atmosphere.
In addition, if it is a cyanoacrylate-based instant adhesive, even a member that is difficult to adhere with an anaerobic adhesive can be bonded extremely strongly, and the type with excellent impact resistance is selected to improve the strength. This is because it can be made to.
The type of such an adhesive is not particularly limited, and is, for example, TL42J (model name) manufactured by 3M, Loctite (trade name) manufactured by Henkel, and the like.

Further, as shown in FIGS. 3 (b) and 4 (b), the second example has a female screw portion corresponding to the screw of the spindle 11 and has a resin ring 17 g as the resin screwing member 18c. It has a first cylindrical member 17a (hereinafter, may be referred to as a first screwing member 17e) as a metal protective cover to be included, and a female thread portion corresponding to the threaded portion of the spindle, and contains a resin ring 17 g. This is an example using a backlash absorbing member 17y provided with a second tubular member 17b (hereinafter, may be referred to as a second screwing member 17f).
In this case, it is composed of a first screwing member 17e fitted to the back side of the accommodating portion 13a of the sleeve 13 and a second screwing member 17f fitted to the inlet side of the accommodating portion 13a of the sleeve 13. .. Then, the second screwing member 17f is fixed to the sleeve 13 by a set screw type fixing member 17d.
Then, in the case of this second example as well, in order to increase the certainty of fixing, in addition to the fixing by the fixing member 17d or instead of the fixing by the fixing member 17d, the first example is also performed. It is also preferable to fix the screwing member 17e and the second screwing member 17f to the accommodating portion 13a of the sleeve 13 with an adhesive.
It is also preferable that the second screwing member 17f is composed of a metal protective cover containing a resin ring 17g.

(6) Action / Effect Next, with reference to FIGS. 4 (a) to 4 (b), the action / effect in stress absorption by the backlash absorbing member 17 (17x, 17y) will be described.
While the spindle 11 is rotationally moving in a predetermined direction, the resin member 17c and the resin ring 17g exhibit a predetermined slipperiness, and do not hinder the operation of the spindle 11 and prevent its rolling and twisting. It can be effectively prevented.
That is, a heat generation phenomenon may occur with the rotational movement of the spindle 11, but the resin member 17c and the resin ring 17g can more efficiently absorb the heat generated by the heat generation phenomenon.
Therefore, the resin member 17c and the resin ring 17g may be partially plasticized by the absorbed heat, but the predetermined slipperiness and the like can be exhibited as they are.
Furthermore, since predetermined metal tubular members (17a, 17b) and screwing members (17e, 17f) are provided on both sides of the resin member 17c and the resin ring 17g, the resin member 17c and the resin ring 17g There is no risk of excessive deformation or outflow from the specified location.

On the other hand, when the rotational movement of the spindle 11 is stopped and the position of the spindle 11 is fixed, the resin member 17c and the resin ring 17g are appropriately deformed and bite into the spindle 11, so that the backlash of the spindle 11 is reduced. can do. Further, even if a stress that causes the spindle 11 to move is applied from the outside, the stress is effectively absorbed by the resin member 17c and the resin ring 17g, and the fixed state can be firmly maintained.
It is preferable that grease is adhered to the contact surface between the backlash absorbing member 17 (17x, 17y) and the sleeve 13. This is because the effect of improving the durability of the backlash absorbing member 17 (17x, 17y), particularly the durability of the resin member 17c and the resin ring 17g can be obtained.

5. Second sleeve The second sleeve 19 is provided between the sleeve 13 and the thimble 15, and has a cylindrical shape coaxial with the sleeve 13 and the thimble 15. Still, while rotating together with the sleeve 13, the second sleeve 19 is fixed to the sleeve 13 and has a scale display (main scale display) on the surface, and the main scale and the auxiliary provided on the thimble 15 are provided. Dimension can be measured by the scale.
The material of the second sleeve 19 is preferably a metal material from the viewpoint of strength and processability, and can be made of, for example, the material exemplified as the material of the sleeve 13, but is particularly preferably made of aluminum or an aluminum alloy.
When the second sleeve 19 is made of aluminum or an aluminum alloy, the second sleeve 19 is anodized, and laser printing is performed on the black surface, which is the alumite-treated surface, to expose the white aluminum cloth, and the scale display is simplified. You can get the effect of being able to do it. Further, by using the second sleeve 19, it is not necessary to consider the process of displaying the scale when selecting the material and the construction method of the original sleeve 13, so that the degree of freedom in designing the original sleeve is improved. Therefore, it is possible to easily manufacture the micro head and reduce the cost.
The length of the second sleeve 19 may be long enough to cover the range of motion of the thimble 15, but is preferably equal to the axial length of the sleeve.
The reason for this is that when the sleeve 13 and the second sleeve 19 are bonded to each other, they can be positioned by simply aligning both ends, and can be manufactured more easily.

[Second Embodiment]
The stage mechanism of the second embodiment includes a predetermined microhead 10 as shown in FIG.
The microhead 10 can be used by incorporating it into various equipment that requires a microhead, such as a micrometer and a stage mechanism. Hereinafter, the stage mechanism including the microhead 10 of the present invention will be described.

1. 1. Basic configuration As shown in FIG. 5, this stage mechanism 30 includes a micro head 10, a fixed stage 31, a movable stage 33, guide members 31a and 33a, a first connection portion 35a, and a second connection portion 35b. And prepare.
The fixed stage 31 is a member that serves as a base for the stage mechanism 30. The movable stage 33 is a member provided on the fixed stage 31, and is a member that moves on the fixed stage 31 in the guide direction of the guide members 31a and 33a in response to the operation of the microhead 10.
In this case, each of the fixed stage 31 and the movable stage 33 has a quadrangular planar shape and the same size as each other, and each has a predetermined thickness. Of course, the shape, size, and thickness of each of the fixed stage 31 and the movable stage 33 are determined according to the specifications of the stage mechanism.
The fixed stage 31 and the movable stage 33 are, for example, aluminum (including alumite-treated aluminum), copper, brass, iron, nickel, magnesium, tungsten, ceramics, polymer resin materials and the like. In particular, alumite-treated aluminum is suitable as a constituent material of the fixed stage 31 and the movable stage 33 because it is excellent in lightness, corrosion resistance, durability, workability, thermal conductivity, decorativeness, economy, and the like. be.

2. 2. Guide member Next, the guide members 31a and 33a will be described with reference to FIGS. 6A to 6C.
In this case, the guide member 31a is a convex portion having a shape in which a part of the fixed stage 31 has the same length as one side of the fixed stage 31 and protrudes upward from the fixed stage 31. On the other hand, the guide member 33a is a concave portion provided on a part of the fixed stage 31 so as to correspond to the convex portion of the guide member 31a and the guide rail 37a.
These convex portions and concave portions are fitted together, and the guide rail 37a is pressed through a hole provided in the movable stage 33 so as to reach the guide rail 37a from the side surface of the movable stage 33, and the side surface of the guide member 31a is fixed. It is pressed moderately by 37 (see FIG. 7 (b)). With such a structure, the movable stage 33 can move on the fixed stage 31 along the guide members 31a and 33a.

The structure of the guide member is not limited to the above example, and other structures may be used. For example, in FIGS. 6A to 6B, the guide members 31a and 31b are one set, but it is preferable to use two sets of the guide members 31a and 31b in parallel. Further, as shown in FIG. 6 (c), it is also preferable to use a guide member using the dovetail groove structures 31x and 33x.
The reason for this is that the number of parts such as guide rails is reduced, manufacturing is easy, and manufacturing is inexpensive.
Although not shown, it is also preferable to use a finite track type guide such as a predetermined cross roller guide or a ball guide or an endless track type guide instead of the guide rail 37a.
The reason for this is that the friction associated with the movement of the movable stage 33 is reduced, and by extension, the force when rotating the spindle can be weakened.

3. 3. First Connection Unit and Second Connection Unit Next, the first connection unit 35a and the second connection unit 35b will be described with reference to FIG.
One end of the first connection portion 35a is fixed to one side surface of the fixing stage 31, and the other end is fixed to the sleeve 13 of the micro head 10.
Further, one end of the second connection portion 35b is fixed to one side surface of the movable stage 33, and the other end is fixed to the spindle 11 of the micro head 10. However, one side surface of the fixed stage 31 and one side surface of the movable stage 33 are the closest side surfaces in a relationship in which they are positioned vertically. Each of the first connection portion 35a and the second connection portion 35b may have a suitable structure.
However, in the case of this embodiment, the second connecting portion 35b has the structure shown in FIG. 5 (c). Further, the portion shown in FIG. 5 (c) is a diagram showing a part of the Q portion in FIG. 5 (b) using a cross-sectional view.
Specifically, a screw hole 11c is provided at the tip of the spindle 11 in the axial direction of the spindle 11. Further, a through hole 35ba is provided at a position of the second connecting portion 35b along the axis of the spindle 11. Using the screw member 35bb passing through the through hole 35ba, the screw member 35bb is turned into the screw hole 11c of the spindle 11, and the screw is prevented from loosening with an adhesive such as a screw lock. Here, it is preferable that the outer diameter of the portion of the screw member 35bb corresponding to the through hole 35ba is set to a minus value within the range of 0.01 to 1 mm as a predetermined tolerance from the diameter of the through hole 35ba.
According to the configuration of the second connection portion 35b, the movement of the spindle 11 can be satisfactorily transmitted to the movable stage 33.

4. Effect Since the microhead 10, the fixed stage 31, and the movable stage 33 are connected by the first connecting portion 35a and the second connecting portion 35b, the operation knob 15c of the microhead 10 is shown in FIG. 5A. When the spindle 11 is rotated left and right as shown by the arrow R in FIG. 5, the spindle 11 moves back and forth along its axial direction, and the movable stage 33 moves in the direction along the arrow S in FIG. 5A in response to this forward and backward movement. Move back and forth.
The backlash reducing effect of the spindle 11 in the present invention is exhibited in the stage mechanism 30 as follows.
That is, as a reaction of the pressing force caused by the rotational movement of the spindle 11, a repulsive stress is generated in which the movable stage 33 of the stage mechanism 30 reverts, but the resin member 17c and the resin ring 17g of the backlash absorbing member 17 are appropriately deformed. Therefore, the repulsive stress can be efficiently absorbed and the backlash in the movable stage 33 can be reduced.

Further, after the movable stage 33 is fixed at a predetermined position, the resin member 17c and the resin ring 17g are in a sufficiently solidified state. As a result, the backlash of the movable stage 33 can be reduced even in the stage mechanism 30.

As described above, according to the present invention, a spindle having a sliding portion and a threaded portion, a sleeve having an accommodating portion, a guide portion, and a stepped portion, a thimble, and a backlash absorbing member fixed to the sleeve are provided. By providing it, it can be expected to effectively reduce backlash and shaft shake even with a simple configuration.
Therefore, for example, a micro head having such a configuration can use a commercially available spindle or the like, so that processing skills or the like are not required, and it is expected that the micro head can be manufactured without a high-performance processing machine or the like.
In addition, it is expected to be widely used in many industrial fields such as precision measuring instruments, optical instruments and processing devices that require the function of finely moving a workpiece.
In addition, when installed at the four corners of the top plate of a laboratory table or the like and used for equilibrium adjustment, it is not necessary to perform locking work to determine the position again after adjusting the height of each, and the equilibrium setting is shortened. Expected to do in time.
Also, when installed on the rotating gear of an optical lens or mirror and used for angle adjustment, a person moves the knob to adjust the laser oscillation direction and mirror, and then shakes when releasing the hand. It is expected to be effectively reduced.
Even when installed in a vacuum chamber such as an electron microscope and used for adjusting the position of a 3-axis stage, the outgas generated from the resin is effectively trapped by wrapping the resin part with a metal protective cover. It can be expected to prevent damage to the pump for evacuation.
Even when it is used for positioning sensors and lens parts such as artificial satellites and cosmic rays, it is expected to suppress the diffusion of outgas and prevent its adhesion to the surface of lenses and the like.

10: _Microhead 11: Spindle 11a: Sliding part 11b: Threaded part 11c: Screw hole 13: Sleeve 13a: Accommodating part 13b: Guide part L: Overall length of sleeve LG: Guide part length _LA : Accommodating part Length LB: Total length of backlash absorbing member _LR : Length occupied by resin screwing member α: Diameter of accommodating part β: Diameter of guide part _D : Diameter of step part 15: Thimble 17, 17x, 17y: Back Rush absorbing member 17a: 1st tubular member 17b: 2nd tubular member 17c: Resin screwing member 17d: Fixing member 17e: 1st screwing member 17f: 2nd screwing member 17g: Resin screwing member 19: No. 2 sleeve 30: stage mechanism 31: fixed stage 33: movable stage 31a, 33a, 31x, 33x: guide member 35a: first connection part 35b: second connection part 35ba: through hole 35bb: screw member 37: fixing member

Claims (8)

Spindles with sliding and threaded parts,
A sleeve having a through hole along the axial direction of the spindle,
A thimble that can rotate around the sleeve as a rotation axis and is partially connected to one end of the spindle,
A microhead comprising a metal screwing member and a resin screwing member, the backlash absorbing member fixed to the sleeve at a position in the sleeve facing the threaded portion of the spindle. There,
A microhead, characterized in that the sleeve has a stepped portion in the middle of the through hole that directly or indirectly abuts on the backlash absorbing member. The sleeve has an accommodating portion for fitting the backlash absorbing member on the thimble side of the step portion, and a guide portion for guiding the slide of the sliding portion to the tip end side of the spindle from the step portion. 1. The following relational expression (1) is satisfied when the diameter of the accommodating portion is α mm, the diameter of the guide portion is β mm, and the diameter of the step portion is D mm. The micro head described in.
α> D ≧ β (1) When the total length of the sleeve is _L (mm) and the length occupied by the guide portion is LG (mm) in the direction along the axis of the spindle, the following relational expression (2) is used. The microhead according to claim 2, wherein the microhead is satisfied.
0.3L ≤ L _G ≤ 0.9L (2) The microhead according to claim 2 or 3, wherein the sleeve has an opening on the thimble side, which serves as a fitting port for the backlash absorbing member to the accommodating portion. The microhead according to any one of claims 1 to 4, wherein the sleeve has a fixing member for preventing the backlash absorbing member from being displaced. When the backlash absorbing member has the total length of the backlash absorbing member as LB (mm) and the length occupied by the resin _{screwing member as LR (} mm) in the direction along the axis of the spindle. The microhead according to any one of claims 1 to 5, wherein the microhead satisfies the following relational expression (3).
0.05L _B ≤ L _R ≤ 0.7L _B (3) When the metal screwing member has two tubular members, one of the tubular members is a first tubular member and the other is a second tubular member, the resin screwing member is the same. The micro head according to any one of claims 1 to 6, wherein the micro head is located between the first tubular member and the second tubular member. The micro head according to any one of claims 1 to 7, wherein the metal screwing member includes a resin ring as the resin screwing member.

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