JP3271922B2 - Micrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a micrometer. More specifically, the present invention relates to a micrometer with reduced cost and weight.

[0002]

2. Description of the Related Art As shown in FIG. 7, a micrometer has a substantially U-shaped main body 101, an anvil 102 held at one end of the main body 101, and an inner sleeve 103 at the other end of the main body 101. Screwed through the anvil 1
02, an outer sleeve 105 fitted and fixed to the outside of the inner sleeve 103, and rotatably fitted to the outside of the outer sleeve 105 and integrally connected to the spindle 105. The structure has a thimble 106 and a ratchet mechanism 107 provided at the rear end of the spindle 104 and spinning when a predetermined load or more is applied to the spindle 104.

A main scale scale 108 is formed on the outer peripheral surface of the outer sleeve 105 at a constant pitch along the axial direction, and a sub-scale scale 109 is formed on the outer peripheral surface of the thimble 106 along the circumferential direction. It is formed at a constant pitch. By these scales 108 and 109, the anvil 10
2 can be measured. That is, the anvil 102 and the spindle 1
04 can be measured.

[0004]

However, the conventional micrometer has a problem that the cost is high because the main body 101 is formed by casting. That is, a mold having a cavity having a body shape is formed, a molten metal of a sintered alloy or ductile cast iron (FCD400) is poured into the mold, and after cooling and solidification of the molten metal, the mold is separated, a cast product is taken out, annealed, and deburring work is performed. After anvil 1
Since the hole processing for press-fitting the inner sleeve 02 and the inner sleeve 103 was performed, there was a problem that it was troublesome and the cost was high.

[0005] In addition, in the case of such a casting, since the weight is heavy, there is a problem that handling and operability are impaired in a micrometer which performs measurement while holding it with one hand. Moreover, when the measurement is performed while holding the body 101 by hand, the heat of the hand is directly transmitted to the body 101,
Since 01 thermally expands, measures are needed to eliminate this effect. Conventionally, as a measure against this point,
Although the cover 110 was attached to the part to be gripped with the hand of the user with screws 01 or the like, the weight increased, the size increased, and the installation was troublesome, resulting in an increase in cost.

An object of the present invention is to provide a micrometer capable of reducing cost and weight. Another object of the present invention is to provide a micrometer capable of suppressing the influence of thermal expansion due to heat of a hand.

[0007]

According to the present invention, there is provided a micrometer having a main body which holds an anvil at one end and a spindle which advances and retreats with respect to the anvil via an inner sleeve at the other end. The main body has a frame formed by bending a metal plate processed into a predetermined shape, and the frame has an anvil holding portion that holds the anvil at one end, and an inner sleeve that holds the inner sleeve at the other end. The holding portions are each bent.

Here, the metal plate is preferably made of a lightweight and highly rigid material. For example, a cold-rolled steel plate (SPC-
C) and the like are good. Since a frame formed by bending such a metal plate is used, while suppressing deformation due to measurement force, that is, while securing the rigidity required at the time of measurement, compared with a casting obtained by conventional casting, Cost reduction and weight reduction are possible.

If a metal plate whose coefficient of thermal expansion is close to the coefficient of thermal expansion of the spindle is used, the elongation of the frame and the elongation of the spindle become substantially the same even when the temperature of the operating environment changes. High accuracy can be maintained without any displacement of the base point. Also, since the anvil holding part and the inner sleeve holding part are bent on the frame,
The conventional hole machining for press-fitting the anvil or inner sleeve can be omitted. Therefore, the cost can be reduced from this point as well.

In the above configuration, the outer surface of the frame may be covered with a resin, or may be painted. Here, as the resin, engineering plastics containing glass fiber having a low thermal conductivity, a thermal expansion coefficient close to that of the frame, and high toughness, heat resistance, flame resistance, and chemical resistance, for example, polyphenylenesal Fight (PPS) is preferred. Also, as the coating material, a material having the same characteristics as the resin is preferable. By using such a resin or coating, the rigidity can be further increased, and even if the frame is grasped by hand at the time of measurement, the heat of the hand is not directly transmitted to the frame. The effect of thermal expansion due to heat can be suppressed.

As a method of coating the outer surface of the frame with a resin, the frame can be formed as an insert part by injection molding of a resin. That is, after setting the frame in the cavity of the mold, the outer periphery thereof can be injection-filled with resin to be molded. With such a method, the anvil is held by the anvil holding portion of the frame and the inner sleeve is held by the inner sleeve holding portion, and these can be integrally connected by the resin. Therefore, the overall rigidity can be increased.

At this time, on the outer peripheral surface of the inner sleeve, the first outer diameter is substantially the same as the inner diameter of the inner sleeve holding portion of the frame.
An annular ridge, a second annular ridge having an outer diameter smaller than the outer diameter of the first annular ridge and having an uneven outer surface, and an annular groove having an outer diameter smaller than the outer diameter of the second annular ridge. Is provided, positioning with the frame can be performed by the first annular ridge,
The annular ridges secure the radial strength, and the annular grooves secure the thrust strength.

The frame may be a single metal plate, but a plurality of metal plates, for example, a pair of frame elements formed by bending a metal plate punched into a predetermined shape are superimposed on each other. It is preferable to use In this case, the rigidity of the frame can be further increased, and a plurality of frame elements are punched by a press or the like, and the frames need only be overlapped with each other. As means for increasing the rigidity of the frame, a rib may be formed along the outer peripheral edge of the frame element.

At this time, if a protrusion is formed on one of the frame elements and a recess is formed on the other, a pair of frame elements can be easily overlapped with high positional accuracy only by fitting them. Further, if a semi-cylindrical portion is formed on each frame element, a circular anvil holding section and an inner sleeve holding section can be formed when a pair of frame elements are overlapped with each other.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the micrometer of the present embodiment. The macrometer includes a substantially U-shaped main body 11, an anvil 21 made of metal (for example, a super-steel alloy) held at one end of the main body 11, and an inner sleeve 31 at the other end of the main body 11. A metal (for example, alloy tool steel: SKS-3) spindle 41 screwed into and out of the anvil 21, an outer sleeve 51 fitted and fixed to the outer side of the inner sleeve 31, and the outer sleeve 51. A thimble 61 rotatably fitted to the outside of the sleeve 51 and integrally connected to the spindle 41; and a ratchet mechanism provided at the rear end of the spindle 41 and idle when a predetermined load or more is applied to the spindle 41. 71.

The main body 11 is composed of a frame 12 formed by bending a metal plate processed into a predetermined shape, and a resin 13 covering the outer surface of the frame 12. That is, it is formed as a laminated structure in which the metal plate frame 12 is used as an insert part and the resin 13 is injection-molded outside the frame. The frame 12 is shown in FIG.
As shown in (1), a metal plate punched into a U-shape by a press or the like (for example, a cold-rolled steel plate: SPC-C)
Frame element 14 formed by folding
A and 14B are formed by overlapping each other. Semi-cylindrical portions 15A, 15B, 16A, 16B constituting holding portions 15, 16 for holding the anvil 21 and the inner sleeve 31, respectively, when overlapped with each other, are provided at both ends of each frame element 14A, 14B. It is bent and the convex 1
7A and 17B and recesses 18A and 18B are formed respectively. In addition, these convex parts 17A and 17B and concave parts 18A and 18B are simultaneously performed at the time of punching of the metal plate by pressing. The resin 13 has a low thermal conductivity, a coefficient of thermal expansion close to that of the frame 12, and has glass fiber-reinforced engineering plastic having high toughness, heat resistance, flame resistance, and chemical resistance, in this case, polyphenylene sal. Fight (PPS) is used.

The inner sleeve 31 is formed by cutting a metal material (for example, lead free-cutting steel: SUM) and fits into the inner sleeve holding portion 16 formed by the semi-cylindrical portions 16A and 16B of the frame 12. The fitting tubular portion 32 to be fitted, the intermediate tubular portion 33, and the spindle 41
And a screw cylinder portion 34 with which the screw portion 42 is screwed. The fitting tube portion 32 has an inner diameter formed so that the outer diameter of the spindle 41 fits without a gap. As shown in FIG. 2, the outer peripheral surface has a first annular ridge 3 whose outer diameter is substantially the same as the inner diameter of the inner sleeve holding portion 16 of the frame 12.
5, second annular ridges 36a, 36b whose outer diameter is smaller than the outer diameter of the first annular ridge 35, and whose outer surface is made uneven by knurling, both sides of the first annular ridge 35 and the second Annular grooves 37a, 37b, 37c are provided between the two annular ridges 36a, 36b and have an outer diameter smaller than the outer diameter of the second annular ridges 36a, 36b. The cross-sectional shape of each of the annular grooves 37a, 37b, 37c is formed in a semicircular groove shape so that the resin 13 can easily go around. The intermediate cylinder 33 has an inner diameter slightly larger than the outer diameter of the spindle 41. The screw tube portion 34 has the spindle 4
One of the screw portions 42 has a female screw 38 to be screwed in, a slit 39 is formed on the peripheral surface along the axial direction, and a nut 40 is screwed.

As shown in FIGS. 3 and 4, the outer sleeve 51 is formed into a cylindrical shape by two-color injection molding of two kinds of resins 52 and 53 having different colors. Specifically, a cylindrical base cylinder 54 and a graduation 55 protruding outward at a constant interval in the axial direction of the outer peripheral surface of the base cylinder 54 are formed by the resin 52. An outer skin 56 that covers the outside of the base cylinder 54 except for the outer cylinder 56 is formed. Numerals 57 are formed on the outer skin 56 by laser marking (irradiating a laser to cause a change in the surface state at the irradiation location to draw symbols, characters, pictures, etc.) corresponding to the scales 55 at regular intervals. ing. Here, the resin 52 is a black resin, the resin 53 is a white resin, and a resin that changes color to black by laser irradiation is used.

As shown in FIGS. 5 and 6, the thimble 61 is formed into a cylindrical shape by two-color injection molding of two kinds of resins 62 and 63 having different colors. Specifically, a cylindrical base cylinder 64 and a graduation 65 protruding outward at a fixed interval position on the outer peripheral surface of the end of the base cylinder 64 are formed by the resin 62, and the graduation 65 portion is formed by the resin 63. An outer skin 66 is formed to cover the outside of the base cylinder 64 except for the outer cylinder 66. A number 67 corresponding to the scale 65 at regular intervals is provided on the outer skin 66.
Are formed by laser marking. here,
The resin 62 is a black resin, the resin 63 is a white resin, and a resin that turns black when irradiated with a laser is used. The resins 52 and 53 forming the outer sleeve 51 and the resins 62 and 63 forming the thimble 61 include the main body 11.
Does not require the high toughness of the resin 13 constituting
A resin having good heat resistance, flame resistance and chemical resistance is preferable.

Next, the manufacturing method will be described. A pair of frame elements 14A,
14B is formed and overlapped with each other to be integrated. At this time, the convex portions 17A, 17B and the concave portions 18A, 18
B is fitted. Then, each frame element 14A, 1
Since the semi-cylindrical portions 15A, 15B, 16A, and 16B of the 4B coincide with each other to form the cylindrical anvil holding portion 15 and the inner sleeve holding portion 16, the anvil holding portion 15 and the inner sleeve holding portion 16 have the anvil. 21
Then, the fitting tube 32 of the inner sleeve 31 is fitted (press-fitted).

After setting the frame 12 in this state as an insert part in a cavity of a mold, a resin 13 is injected and filled into the cavity. Then, the resin 13 filled in the cavity covers the outside of the frame 12 and also between the anvil holding portion 15 and the anvil 21 and between the inner sleeve holding portion 16 and the fitting cylindrical portion 32 of the inner sleeve 31. It penetrates (see the state of FIG. 1).
Thereby, the frame 12, the anvil 21 and the inner sleeve 31 are integrally connected.

Next, the outer sleeve 51 is fitted and fixed to the outer side of the inner sleeve 31, and the spindle 41 is inserted inside the inner sleeve 31.
The first screw portion 42 is screwed into the female screw 38 of the inner sleeve 31. At this time, the clearance between the two is
Adjust with. Subsequently, the thimble 61 is fitted to the outside of the outer sleeve 51, and the thimble 61 and the spindle 41 are integrated by the ratchet mechanism 71. Thereby, a micrometer is manufactured.

According to this embodiment, the anvil 21 is provided at one end.
And the main body 11 holding the spindle 41 at the other end via the inner sleeve 31 is formed by the frame 12 formed by punching and bending a metal plate. The cost can be reduced and the weight can be reduced as compared with the casting obtained by the conventional casting, while maintaining the accuracy with respect to the temperature change. Therefore, improvement in handling and operability can be expected.

In addition to the main body 11, not only the outer sleeve 51 and the thimble 61 but also the resins 52, 53,
Since it is formed by 62 and 63, the weight of the entire micrometer can be reduced. Therefore, also from this point, improvement in handling and operability can be expected. In addition, the weight of the micrometer is not reduced partially but is reduced as a whole, so that the weight balance, which is a problem in using the micrometer, can be maintained.

Further, since the outer surface of the frame 12 is covered with the resin 13 by injection molding of the resin 13 using the frame 12 as an insert part, the frame 12 is used for measurement.
Even if is grasped by hand, the heat of the hand is not directly transmitted to the frame 12, so that the effect of thermal expansion due to the heat of the hand can be suppressed while maintaining the weight reduction. In addition, the outer sleeve 51 and the thimble 61 also have resins 52, 53,
Since the thimble 61 is formed by the fingers 62 and 63, even when the thimble 61 is gripped and turned by the finger, the heat of the finger is hardly transmitted to the spindle 41, so that the influence of the thermal expansion due to the heat of the hand can be suppressed.

Further, since a pair of frame elements 12A and 12B formed by punching and bending a metal plate are used for the frame 12, the rigidity of the frame 12 can be further increased. A plurality of frame elements 12A and 12B are punched out by a press or the like, and these pieces need only be overlapped with each other. Moreover, the protrusions 17A, 17B are provided on one of the frame elements 12A, 12B.
Since the recesses 18A and 18B are formed on the other side, a pair of frame elements 12A and 1
2B can be easily overlapped with high positional accuracy.

Further, since the semi-cylindrical portions 15A, 15B, 16A, 16B are formed on each of the frame elements 12A, 12B, when the pair of frame elements 12A, 12B are overlapped with each other, the circular anvil holding portion 15 and the inner The sleeve holding portion 16 can be configured. In addition, the anvil 21 is mounted on the anvil holding portion 15 and the fitting sleeve 3 of the inner sleeve 31 is mounted on the inner sleeve holding portion 16.
Since the injection molding of the resin 13 is performed by using these as insert parts in a state where the 2 is press-fitted, they can be integrally connected by the resin 13. Thereby, the overall rigidity can be increased.

The fitting sleeve 32 of the inner sleeve 31
A first annular ridge 35 whose outer diameter is substantially the same as the inner diameter of the inner sleeve holding portion 16 of the frame 12;
Second annular ridges 36a and 36b whose outer surfaces are smaller and smaller than the outer diameter of the annular ridge 35;
Annular grooves 37a, 37 smaller than the outer diameter of 6a, 36b
b, 37c, the first annular ridge 35 allows positioning with respect to the frame 12, and the second annular ridge 36
The coupling strength in the radial direction can be secured by a and b, and the coupling strength in the thrust direction can be secured by the annular grooves 37a, 37b and 37c.

The outer sleeve 51 and the thimble 61 are made of two kinds of resins 52, 53, 62, 6 having different colors.
After molding including the graduations 55 and 65 by two-color injection molding of No. 3, the numerals 57 and 67 are formed by laser marking, so that their production can be simplified and inexpensive.

In the above-described embodiment, the frame 12 is formed by superimposing a pair of frame elements 12A and 12B. However, only one or three or more frame elements may be superimposed. As means for increasing the rigidity of the frame 12 as necessary, a rib may be formed along the outer peripheral edge of each frame element 12A, 12B. Further, in the above embodiment, the outer surface of the frame 12 is covered with the resin 13, but the outer surface may not be particularly covered with the resin 13, or
A coating having heat resistance, flame resistance, and chemical resistance may be applied.

In the above embodiment, the outer sleeve 51 and the thimble 61 are molded including the scales 55 and 65 by two-color injection molding of two kinds of resins 52, 53, 62 and 63 having different colors. Number 57, 67
Is formed by laser marking, but numerals 57 and 67 may be formed together with the graduations 55 and 65 by the resin 52 and 62 which form the base cylinders 54 and 64 from the beginning, or the numerals may be formed by laser. 5
The portions 7 and 67 may be removed.

[0032]

According to the micrometer of the present invention, a metal plate formed into a predetermined shape is formed on a body holding an anvil at one end and a spindle at the other end via an inner sleeve. Because the frame used is, the rigidity required at the time of measurement and the accuracy with respect to temperature changes in the use environment are secured, and compared to conventional castings
Cost reduction and weight reduction are possible. Further, since the outer surface of the frame is covered with resin or paint, the influence of thermal expansion due to heat of the hand can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a micrometer according to the present invention.

FIG. 2 is an exploded perspective view showing a main part of the embodiment.

FIG. 3 is a front view showing an outer sleeve of the embodiment.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a front view showing the thimble of the embodiment.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a perspective view showing a conventional micrometer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Main body 12 Frame 13 Resin 14A, 14B Frame element 15 Anvil holding part 15A, 15B Semi-cylindrical part 16 Inner sleeve holding part 16A, 16B Semi-cylindrical part 17A, 17B Convex part 18A, 18B Concave part 21 Anvil 31 Inner sleeve 35 No. 1 annular ridge 36a, 36b second annular ridge 37a, 37b, 37c annular groove 41 spindle

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshihiko Mishima 6-8-20 Hiroko Shinkai, Kure-shi, Hiroshima Pref. Mitutoyo Corporation (56) References JP-A-4-198801 (JP, A) JP-A-59-110953 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 3 / 00-3/56

Claims (8)

(57) [Claims] 1. A micrometer having a main body that holds an anvil at one end and a spindle that advances and retreats with respect to the anvil at the other end via an inner sleeve, wherein the main body is formed of a metal plate processed into a predetermined shape. It has a frame formed by bending, and the frame has an anvil holding portion for holding the anvil at one end, and an inner sleeve holding portion for holding the inner sleeve at the other end. Characteristic micrometer. 2. The micrometer according to claim 1, wherein an outer surface of the frame is covered with a resin. 3. The micrometer according to claim 1, wherein the outer surface of the frame is coated. 4. The micrometer according to claim 1, wherein the frame comprises a pair of frame elements formed by bending a metal plate punched into a predetermined shape. A micrometer characterized by being formed. 5. The micrometer according to claim 4, wherein a projection is formed on one of the frame elements and a recess is formed on the other of the frame elements so as to be fitted to the projection. Meter. 6. The micrometer according to claim 4, wherein the frame element has a semi-cylindrical portion that constitutes each of the holding portions when overlapped with each other. Micrometer. 7. The micrometer according to claim 4, wherein a rib is formed along an outer peripheral edge of the frame element. 8. The micrometer according to claim 2, wherein an outer diameter of the outer peripheral surface of the inner sleeve held by the inner sleeve holding portion is substantially equal to an inner diameter of the inner sleeve holding portion of the frame. A ridge, a second annular ridge having an outer diameter smaller than the outer diameter of the first annular ridge and an uneven outer surface, and an annular groove having an outer diameter smaller than the outer diameter of the second annular ridge A micrometer characterized by having a ridge.