JPH08108327A - Positioning device - Google Patents

Abstract

PURPOSE: To provide a positioning device, which can smoothly move a movable stand on a base. CONSTITUTION: A positioning device is provided with a movable stand, to which a micrometer is fitted, a base 68 having a guide unit for guiding a movable stand, and a moving means arranged between the movable stand and the base 68 and for moving the movable stand along the predetermined direction. This moving means has a female screw hole 74 provided in the base 68 and a screw rod 76, which is screwed into the female screw hole 74 and of which one end is connected to the movable stand freely to be turned so as to move the movable stand. This device also has an auxiliary hole 12 provided in the base 68 and opened in the inner peripheral surface of the female screw hole 74, a presser body 14 made of synthetic resin, which abuts on the outer peripheral surface of the screw rod 76, and a pre-load screw 16 for always giving the pre-load in the screw rod direction to the presser body 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device, and more particularly to a positioning device having a movable table rattling prevention mechanism to which a member to be positioned is mounted.

[0002]

2. Description of the Related Art First, the configuration of a conventional positioning device 50 will be described with reference to FIG. As an example, the member to be positioned attached to the positioning device 50 is the micrometer 5.
The case of 2 will be described. The micrometer 52 is fixed to a stand 56 placed on a surface plate 54, as shown in FIG. A columnar object 58 is placed on the turntable 60 on the surface plate 54, and is rotatable about an axis X. The micrometer 52 is the object 5 to be measured.
The measuring tentacle 62 of the micrometer 52 is provided on the side of the rotary table 60 to measure the roundness of the object 5.
It is arranged so as to be always in contact with the outer peripheral surface of 8. Note that the micrometer 52 of this example uses a lever type dial gauge as an example.

In this case, the detection tentacle 62 is always in contact with the object 58 to be measured.
The stand 56 is delicately moved on the surface plate 54 so that the displacement amount of the irregularities on the outer peripheral surface of the measured object 58 falls within the maximum swing amount of the detection tentacle 62 in order to make contact with the outer peripheral surface of the object 58. It is necessary to determine the position of the micrometer 52 at. Since it takes time and effort to move the stand 56 itself delicately on the surface plate 54, conventionally, the micrometer 52 is fixed to the stand 56 via the positioning device 50 as shown in FIG. The positioning device 50 is used to move the micrometer 52 when the micrometer 52 is brought into contact with the outer peripheral surface of the measured object 58.

The configuration of the positioning device 50 will be described in detail with reference to FIG. Reference numeral 64 denotes a movable table on which the micrometer 52 as a member to be positioned is fixed using screws 66.
Reference numeral 68 denotes a base, which is provided with a guide portion 70 for guiding the movable base 64 so as to be movable only in a predetermined direction (arrow Y direction). The guide part 70 is formed in a dovetail groove as an example. Reference numeral 72 denotes a moving means, which includes a moving table 64 and a base 68.
And has a function of moving the movable table 64 along the arrow Y direction.

[0005] The structure of the moving means 72 will be described in more detail. Reference numeral 74 denotes a female screw hole, which is provided on the base 68 in parallel with the arrow Y direction. Reference numeral 76 denotes a screw rod, which is screwed into the female screw hole 74, and one end (the left end in FIG. 6) is rotatably connected to the movable base 64, and the other end (in FIG. 6). A knob 78 is formed at the right end). Note that the left end of the screw rod 76 is rotatably connected by fitting a projection 82 provided on the movable base 64 into a circumferential groove 80 formed at the left end. With this configuration, when the knob 78 is rotated, the screw rod 76 moves
The moving table 64 moves in the direction, and the moving table 64 can move on the base 68. Reference numeral 84 denotes a fixing screw for fixing the movable base 64.

[0006]

However, the above-mentioned conventional positioning device has the following problems. Female screw hole 7
Since there is always backlash between the screw 4 and the screw rod 76 screwed into the female screw hole 74 and screwed back, the knob 78 is rotated to move the movable table 64 to a predetermined position. There is a problem that even when the movable table 64 is moved, when the movable table 64 is fixed to the base 68 by the fixing screw 84, the movable table 64 moves delicately, and the position of the member to be positioned is shifted. Also, the base 68
The guide portion that guides the movable table 64 and the movable table 64 only in a predetermined direction is formed in a dovetail groove, which is an example of the sliding guide, so that there is always backlash, and the movable table 64 is displaced when fixed.

For this reason, conventionally, instead of a sliding guide such as a dovetail groove for a guide portion, a rolling guide which can be lightly moved by applying a preload without any backlash has been adopted. Rolling guide is the base 6 as shown in FIG.
A plurality of steel balls 86 are arranged between the movable table 64 and the movable table 64, and the rolling movement is performed by the steel balls 86. The two pairs of steel wires 88 and 90 disposed on both sides of the steel ball 86 have a function as a rail. Further, 92 is a tightening screw as a preload means for applying a preload, and 94 is a preload steel plate for applying a pressure from the tightening screw 92 to each of the pair of steel wires 90. However, the preloaded steel sheet 94
Of the parallelism of both sides of the sheet and the preloaded steel plate 9 for the tightening screw 92
In view of the flatness of the abutting end surface with respect to No. 4, and the relationship between the dimensional processing accuracy of the diameter of each of the pair of steel wires 88 and 90 that should originally be formed to have the same diameter, the pair of steel wires 90 is When the preload steel plate 94 is not located on the plane orthogonal to the tightening direction of the tightening screw 92, or when the preload steel plate 94 is inclined, the preload steel plate 94 is uniformly applied to both of the pair of steel wires 90.
May not come into contact with each other. For this reason, there is a problem that the play also occurs when the movable table 64 moves. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-described problems, and an object of the present invention is to provide a positioning device that can move a moving table smoothly on a base without play.

[0008]

The present invention has the following constitution in order to achieve the above object. That is, the first positioning device according to the present invention is a moving base to which a member to be positioned is attached, a base having a guide portion for guiding the moving base only in a predetermined direction, the moving base and the base. And a moving means for moving the moving base along the predetermined direction, the moving means being provided in the base and parallel to the predetermined direction. And a screw rod that is screwed into the female screw hole and has one end abutting the movable table or rotatably connected to the movable table to move the movable table along the predetermined direction.
An auxiliary hole provided on the base and opening on the inner peripheral surface of the female screw hole; a synthetic resin pressing body mounted in the auxiliary hole and in contact with the outer peripheral surface of the screw rod; and the pressing body. Preloading means for constantly applying a preload in the direction of the rod is provided. By adopting this configuration, the screw rod screwed into the female screw hole is constantly pre-loaded from the pre-loading means through the synthetic resin pressing body, preventing the screw rod from rattling in the female screw hole. it can.

A second positioning device according to the present invention is arranged such that a movable base to which a member to be positioned is attached, a base, and the base and the movable base are arranged. In a positioning device comprising a guide part which guides the movable base only in a predetermined direction, and a moving means which is disposed between the movable base and the base and which moves the movable base along the predetermined direction, The guide portion is formed in one of the movable table or the base table and a guide groove formed in parallel with the predetermined direction, and in the other of the movable table or the base table,
A fitting convex portion that can be fitted in the guide groove, a first concave groove provided on both outer side surfaces of the fitting convex portion in parallel with the predetermined direction, and both inner side surfaces of the guide groove, A second groove provided to face the first groove, two first steel wires arranged at a corner of a bottom surface of the first groove, and the second groove At the corners of the bottom surface of the two second steel wires arranged in parallel with the first steel wire.
Steel wire, a plurality of steel balls arranged between the first steel wire and the second steel wire, and at least one groove of the first groove or the second groove. A preload steel wire disposed in parallel with the steel wire between the bottom surface of the groove and the two first steel wires or the second steel wire, and the preload steel wire. , The above 2
It is a rolling guide having a preload means for applying a preload in the direction of the first steel wire or the second steel wire of the book. When this configuration is adopted, even if the first steel wire or the second steel wire to which the preload is applied from the preload steel wire is not in the position orthogonal to the preload direction, the space between the first steel wires or the second steel wire Since the preload steel wire enters between them and can surely come into contact with the first steel wire or the second steel wire, the movable table can be moved without backlash. Further, since the preload steel wire has a circular cross section, the preload means can reliably press the preload steel wire even if the contact surface of the preload means with the preload steel wire is not flat.

[0010]

In the first positioning device of the present invention, the screw rod screwed into the female screw hole is constantly preloaded from the preloading means through the pressing member made of synthetic resin, so that the screw rod is inserted in the female screw hole. It does not rattle, and therefore the moving table does not rattle. In the second positioning device of the present invention, since the preload is applied to the first steel wire or the second steel wire via the preload steel wire, the first steel wire or the second steel wire is applied in the preload direction. Even if they are not orthogonal to each other, the preload steel wire enters between the first steel wires or between the second steel wires and always comes into contact with the first steel wire or the second steel wire. Further, since the preload steel wire has a circular cross section, the preload means can be pressed without rattling even if the contact surface of the preload means with the preload steel wire is not flat.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a positioning device according to the present invention will be described below in detail with reference to the accompanying drawings. As in the conventional example, as an example, the member to be positioned is the micrometer 52, and the positioning device 10 is used as a device for measuring the roundness of the cylindrical object to be measured 58 mounted on the rotary table 60. The case will be described. First, the configuration of the positioning device 10 will be described, but a configuration that is particularly different from the positioning device 10 described in the conventional example will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

First, the structure of the moving means 72 is different, and will be described in detail with reference to FIGS. Reference numeral 12 denotes an auxiliary hole, which is formed in the base 68 so as to open from both side surfaces of the base 68 to the inner peripheral surface of the female screw hole 74. In this embodiment, the two auxiliary holes 12 have the same center line and are formed so that the center lines are orthogonal to the center line of the female screw hole 74. Also, as in this embodiment, the auxiliary holes 12
May be arranged only on one side instead of being arranged on both sides of the female screw hole 74. Reference numeral 14 denotes a cylindrical pressing body made of a synthetic resin mounted in each auxiliary hole 12. The pressing body 14 comes into contact with the outer peripheral surface of the screw rod 76. 16 is each auxiliary hole 1
2 is a preload screw as preload means screwed into the inside 2. Each preload screw 16 is screwed together after each pressing body 14 is attached to the auxiliary hole 12.

Secondly, the connecting structure of the screw rod 76 and the moving base 64 is different, which will be described in detail with reference to FIGS. 1 and 3.
One end (the left end in FIG. 1) of the screw 76 is inserted and fixed in the inner ring 19 of the radial ball bearing 18. The moving table 64 is provided with a circular hole 20 into which the radial ball bearing 18 can be inserted. Inside the circular hole 20, a screw hole 22 that opens to the outer surface of the moving table 64 is formed. Screw 7
6 and the moving table 64, the radial ball bearing 18 attached to one end of the screw rod 76 is inserted into the circular hole 20, and the outer ring 24 of the inserted radial ball bearing 18 is screwed into the screw hole 22. A circular hole 20 is formed at the conical tip of the connecting screw 26.
It is connected by pressing against the bottom of the. With this structure, the screw 76 is smoothly and rotatably connected to the movable base 64. The inner ring 1 of the radial ball bearing 18
Since a plurality of rolling steel balls 28 are arranged between the outer ring 9 and the outer ring 24, there is always play between the inner ring 19 and the outer ring 24. In this embodiment, in order to suppress this play. A spring body (not shown) is arranged between the moving base 64 and the base 68, and constantly urges the moving base 64 toward the base 68 in either the left direction or the right direction in FIG. ing.

Third, the configuration of the guide section 70 is different, and will be described in detail with reference to FIGS. The guide portion 70 of the present embodiment is formed in the rolling guide described in the conventional example, and details thereof will be described. Reference numeral 30 denotes a guide groove, which is recessed in the base 68 in parallel with the screw rod 76. 32
Is a fitting convex part fitted in the guide groove 30,
4 has been extended. Reference numeral 34 denotes a first concave groove provided on both outer surfaces of the fitting projection 32 in parallel with the extending direction of the fitting projection 32. Reference numeral 36 denotes a second concave groove provided on both inner side surfaces of the guide groove so as to face the first concave groove 34.

The first steel wires 88 are arranged one by one at the bottom corners of the first groove 34. The second steel wire 90 is and is arranged in parallel with the first steel wire 88 one by one in the vicinity of the bottom corner of the second groove 36. First steel wire 88 and second
A plurality of steel balls 86 are arranged between the steel wire 90 and
A holding plate (not shown) holds the steel balls 86 so that the distance between them is constant. 38 is inside the second groove 36,
Between the bottom surface of the concave groove 36 and the two second steel wires 90,
It is a preload steel wire arranged in parallel with the steel wire 90. A tightening screw 92 as a preload means is screwed to the base 68 so that its tip can protrude into the second groove 36 in order to apply a preload to the preload steel wire 38 in the direction of the two second steel wires 90. Have been.

The preload steel wire 38 and the tightening screw 92
May be provided in both of the second concave grooves 36, or the preload steel wire 38 may be arranged in the first concave groove 34 instead of in the second concave groove 36. Moving means 6
4 to apply a preload to the first steel wire 88. Further, the guide groove 30 may be provided on the movable base 64, and the fitting protrusion 32 may be provided on the base 68.

With the above configuration, the preload screw 16 mounted on the auxiliary hole 12 is screwed into the screw rod 76 screwed into the female screw hole 74 of the base 68 by using the driver 40 or the like, so that the preload from the pressing body 14 is reduced. Therefore, the play in the female screw hole 74 can be suppressed. Moreover, since the pressing body 14 is formed using a synthetic resin material having elasticity, once the preload screw 16 is screwed in, the preload can be constantly applied to the screw rod 76 until the contact surface with the screw rod 76 is worn. Further, the metal screw rod 76 can also be rotated in a state where a preload is always applied since the pressing body 14 is elastically deformable.

Further, by screwing the tightening screw 92, the preload steel wire 38 can uniformly contact both of the two second steel wires 90, and a preload in the direction of the steel ball 86 can be applied. Thus, the movement of the movable table 64 can be performed without play. Further, since the preloaded steel wire 38 is used in place of the preloaded steel sheet 94 as in the conventional example, it is not necessary to secure the preloaded steel sheet 94 having a high degree of parallelism on both sides, which is advantageous in cost. Even when the flatness of the end surface of the tightening screw 92 abutting on the preload steel plate 94 or the dimensional accuracy of the diameter of each of the pair of steel wires 88 and 90 is poor, the circular cross-section of the second steel wire 90 has the same When the preload steel wire 38 enters, the preload steel wire 3
It is possible to uniformly apply a preload to the two second steel wires 90 from 8. If the condition that the total dimension of the diameter of the preload steel wire 38 and each second steel wire 90 is longer than the groove width of the second concave groove 36 is satisfied, the preload steel wire 38 is the same as the second steel wire 90. The use of steel wire is also possible, which is more cost effective.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the positioning device positions a member other than a micrometer as a member to be positioned. May be used for purposes, etc.
Of course, many modifications can be made without departing from the spirit of the invention.

[0020]

When the first positioning device according to the present invention is used, the screw rod screwed into the female screw hole is constantly preloaded from the preloading means through the synthetic resin pressing body. The screw rod does not rattle in the hole, so that the movable table can be accurately positioned. Further, when the second positioning device is used, the preload is applied to the first steel wire or the second steel wire through the preload steel wire having the circular cross section, so that the first steel wire or the second steel wire is Even if the preload steel wire is not in a position orthogonal to the preload direction, the preload steel wire may enter between the first steel wires or the second steel wires and always come into contact with the first steel wire or the second steel wire,
Preload is reliably applied to the first steel wire or the second steel wire,
It has a remarkable effect that the movable table can be moved without backlash.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a positioning device according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, showing the structure of a screw rod, an auxiliary hole, a pressing body, and a preload screw.

FIG. 3 is a BB diagram showing a connection structure between the moving table and the screw rod in FIG. 1;
It is sectional drawing.

FIG. 4 is an enlarged cross-sectional view of a main part showing a structure of a preload steel wire and a tightening screw in the rolling guide of FIG.

FIG. 5 is a plan view showing an example of a conventional positioning device.

FIG. 6 is an explanatory diagram showing a configuration of an apparatus for measuring the circularity of a measured object by a micrometer.

FIG. 7 is an explanatory diagram showing a general structure of a rolling guide.

FIG. 8 is an enlarged sectional view of a main part showing a structure of a preload steel plate and a tightening screw in a conventional rolling guide.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Auxiliary hole 14 Pressing body 16 Preload screw 52 Micrometer 64 Moving table 68 Base 70 Guide part 72 Moving means 74 Female screw hole 76 Screw rod

Claims (2)

[Claims] 1. A movable base to which a member to be positioned is attached, a base having a guide portion for guiding the movable base only in a predetermined direction, and a base arranged between the movable base and the base. In a positioning device including a moving unit that moves a moving table along the predetermined direction, the moving unit is provided in the base and has a female screw hole parallel to the predetermined direction, and a female screw hole in the female screw hole. A screw rod that is screwed and has one end abutting the movable table or rotatably connected to the movable table to move the movable table in the predetermined direction, and is provided on the base, and An auxiliary hole that opens to the inner peripheral surface of the female screw hole, a synthetic resin pressing body that is mounted in the auxiliary hole and contacts the outer peripheral surface of the screw rod, and a preload in the screw rod direction is constantly applied to the pressing body. A positioning device, characterized by comprising: . 2. A movable base to which a member to be positioned is attached, a base, and a movable base arranged between the base and the movable base, and the movable base is guided so as to be movable only in a predetermined direction on the base. In a positioning device comprising a guide unit and a moving unit that is arranged between the movable table and a base and moves the movable table along the predetermined direction, the guide unit is the movable table or the base. A guide groove formed in one of the stands parallel to the predetermined direction, a fitting projection formed in the other of the moving stand or the base, and capable of fitting in the guide groove, and the fitting projection. A first groove provided on both outer side surfaces of the guide groove in parallel to the predetermined direction, and a second groove provided on both inner side surfaces of the guide groove so as to face the first groove. , Two first steel wires arranged in a bottom corner of the first groove, and a bottom corner of the second groove And two second steel wires arranged in parallel with the first steel wire, a plurality of steel balls arranged between the first steel wire and the second steel wire, In at least one groove of the first groove or the second groove, between the bottom surface of the groove and the two first steel wire or the second steel wire, A rolling guide having a preload steel wire arranged in parallel with the steel wire and a preload means for applying a preload to the preload steel wire in the direction of the two first steel wires or the second steel wire. Positioning device characterized by the above.