JPH0421053Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a digital display micrometer, and particularly to a linear digital display micrometer that is small in size and highly accurate, and has a linearly moving spindle.

[Background Art and Problems Therein] Compared to mechanical scale display type measuring instruments, electronic digital display type measuring instruments are becoming popular among measuring instruments in general due to their advantages such as high accuracy and easy readability.

Even in the case of micrometers, digital displays incorporating rotary encoders are progressing for micrometers in which the spindle rotates as the thimble rotates and advances and retreats in the axial direction. A rotary encoder, whether photoelectric or capacitive, basically electrically detects the relative rotation angle between a fixed plate and a rotary plate, and is advantageous in terms of small size and high accuracy.

However, in order to measure objects with thin grooves, such as spline shafts, where the spindle simply moves straight without rotating, there are various problems when incorporating a rotary encoder and creating a digital display. However, a product of practical use has yet to emerge.

This is because the spindle only moves in a straight line, so it is difficult to connect the rotating plate of the rotary encoder to synchronously rotate.
Even if it were possible to rotate the rotary plate in synchronization with the rotation of the thimble, this encoder and a mechanism for converting the rotation of the thimble into linear movement of the spindle would have to be installed inside the main body frame, which would increase the size and make handling difficult. Moreover, if the stroke of the spindle becomes large, sufficient support for the spindle cannot be obtained, making it impossible to ensure the straightness of spindle movement and parallelism between measurement surfaces, and as a result, measurement accuracy cannot be guaranteed. This is thought to be caused by the following.

[Purpose of invention]

An object of the present invention is to solve these problems and provide a compact and highly accurate linear digital display micrometer.

[Means and actions for solving problems]

Therefore, the configuration of the present invention includes a main body having an anvil at one end, and a pair of tapered parts provided at the other end of the main body so as to be non-rotatable and displaceable in the axial direction of the anvil and spaced apart by a predetermined distance in the longitudinal direction. and a thimble, which is rotatably fitted between the tapered portions of the spindle with both ends in contact with each other, and is screwed into a threaded portion formed in the main body along the axial direction of the spindle. An inner cylinder that rotates integrally with the inner cylinder, a rotating plate that can rotate in synchronization with the inner cylinder and cannot be displaced in the axial direction of the inner cylinder, and a fixed plate that is fixed to the main body with a constant gap between the rotating plate and the rotating plate. and an encoder that detects the displacement amount of the spindle from the relative rotation angle of the two plates, and a digital display that digitally displays a measured value based on the output signal of the encoder. .

Therefore, when the thimble is rotated, the inner cylinder moves forward and backward in the axial direction while rotating. Then, as the inner cylinder moves back and forth in the axial direction, the spindle moves straight without rotating, and the rotation of the inner cylinder is detected by the encoder. Therefore, the encoder is actuated by the rotation of the inner cylinder that is fitted onto the spindle, so the overall size can be made smaller, and since the spindle is supported by the inner cylinder by a pair of tapered parts in the longitudinal direction, the spindle can be easily moved. High accuracy can be maintained even with large strokes.

〔Example〕

FIG. 1 shows a linear digital display type micrometer of this embodiment. In the same figure, a frame 1 as a main body formed in a substantially U-shape includes:
An anvil 2 is fixed to the inner surface of one end, and a spindle 4 is held at the other end so as to be movable in the axial direction, the spindle 4 moving linearly forward and backward with respect to the anvil 2 as the thimble 3 is rotated. . As shown in FIG. 2, the abutment ends of the anvil 2 and the spindle 4 are formed in a so-called blade shape, with both sides gradually becoming thinner toward the tip.

Further, on the front side of the other end of the frame 1 holding the spindle 4, there is a digital display 5 for digitally displaying the amount of movement of the spindle 4, as well as a display for holding the value displayed on the digital display 5. A hold switch 6, a display unit changeover switch 7 for switching the displayed value of the digital display 5 between inches or mm, a preset switch 8, and a mode changeover switch 9 are provided, respectively.

In addition, a bearing tube 1 is provided on the inner side of the other end of the frame 1.
1 is fixed so as to protrude toward the anvil 2, and a retaining ring 2 is attached to the outer surface of the other end of the frame 1.
1 are screwed together. The spindle 4 is supported by the bearing sleeve 11 so as to be non-rotatable and movable in the axial direction of the anvil 2 . The spindle 4 has a tapered part 12 in the middle that becomes smaller in diameter toward the other end, and slides onto a screw 13 protruding from the bearing sleeve 11 in a large diameter part 4A bordering on the tapered part 12. A key groove 14 that can be freely engaged is formed along the axial direction, and a screw 15 is provided on the distal end side of the small diameter portion 4B.
is formed. A tapered receiving piece 16 having a tapered surface facing the tapered surface of the tapered portion 12 at a predetermined distance is screwed into the male thread 15. Here, the tapered piece 16 and the tapered portion 12 constitute a pair of tapered portions.

Furthermore, one end sides of an inner sleeve 22 and an outer sleeve 23, which fit into the double cylinder structure inside and outside, are held in the center of the retaining ring 21, respectively. The inner sleeve 22 has a small-diameter cylindrical portion 22A formed at one end thereof, and has a cylindrical shape that can be expanded and contracted by a plurality of slits 24 formed along the axial direction at the other end. On the other end side of the inner sleeve 22, a female thread 25 as a threaded portion is formed coaxially with the spindle 4 along the axial direction of the spindle 4 on its inner circumferential surface, and a taper nut 26 is screwed onto the outer circumferential surface. A male thread 27 is formed.

The female thread 25 of the inner sleeve 22 is provided between the tapered portions of the spindle 4, that is, the tapered portion 12.
An inner cylinder 31 is rotatably fitted between the inner cylinder 31 and the tapered receiving piece 16 with both ends in contact with each other. The inner cylinder 31 includes a large diameter cylinder part 31A having a thread 32 on the outer periphery that is screwed into the female thread 25 of the inner sleeve 22, and a small diameter cylinder part 31A that is slidably inserted into the small diameter cylinder part 22A of the inner sleeve 22. Cylinder part 3
1B are connected to each other, and inner peripheral edges at both ends are formed into a tapered surface shape.

The other end of the thimble 3, which is rotatably fitted onto the outer peripheral surface of the outer sleeve 23, is integrally held at the other end of the large diameter cylindrical portion 31A via a nut 33. . A second thimble 34 is screwed onto the outer periphery of the other end of the thimble 3, and a ratchet thimble 36 is attached to the second thimble 34 via a ratchet 35. This allows thimble 3 or ratchet thimble 36
When rotated, the inner cylinder 31 integrated with the thimble 3 moves back and forth in the axial direction while rotating, so the spindle 4 moves back and forth with respect to the anvil 2 without rotating. At this time, the amount of movement of the spindle 4 is determined by the main scale graduations 37 formed at regular intervals along the axial direction of the outer circumferential surface of the outer sleeve 23 and the vernier scale graduations 38 formed along the outer circumference of the thimble 3. Can be read.

On the outer periphery of the inner cylinder 31 between the bearing cylinder 11 and the end face of the small diameter cylinder part 22A of the inner sleeve 22, a rotating cylinder 41, a spacer 42, and a collar 43 are fitted so as to be displaceable in the axial direction in this order. ,
These collars 4 are placed between the collar 43 and the bearing sleeve 11.
3. A spring 44 is inserted as a biasing means for biasing the spacer 42 and the rotary cylinder 41 to the right in FIG. The collar 43 is displaceable in the axial direction of the inner cylinder 31 and is attached to a set screw 4 provided in the bearing cylinder 11.
5, it is fixed to the bearing sleeve 11, that is, to the frame 1. Further, the rotating cylinder body 4
1 includes a protrusion 47 that slidably engages with a key groove 46 formed along the axial direction of one side of the inner cylinder 31.
Two screws 48A and 48B are screwed together. These two screws 48A, 48B not only enable the rotary cylinder body 41 and the inner cylinder 31 to rotate synchronously and displace in the axial direction, but also provide means for integrally fixing the rotary cylinder body 41 to the inner cylinder 31. Also serves as.

An encoder 51 is provided between the rotating cylindrical body 41 and the small diameter cylindrical portion 22A of the inner sleeve 22. The encoder 51 is connected to the retaining ring 21
A fixing plate 53 having a transmitting electrode and an output electrode (not shown) is adhesively fixed to a plate 52 fixed to the rotating cylinder 41, and a fixing plate 53 is adhesively fixed to the rotary cylinder 41 in a state facing the fixing plate 53 with a certain gap, and is not shown in the figure. The rotary plate 54 has a receiving electrode and a coupling electrode that are not connected to each other, and when a signal with a different phase is applied to the transmitting electrode, a signal corresponding to the relative rotation angle between the fixed body 53 and the rotating plate 54 is obtained from the output electrode. It's getting old. The fixing plate 53 is fixed at a position inside a predetermined reference gap from the end face of the small diameter cylindrical portion 22A of the inner sleeve 22, and its lower part is fixed to the frame 1. Further, the rotating plate 54 is fixed flush with the end surface of the rotating cylinder 41 facing the fixed plate 53. In addition, encoder 5
The signal corresponding to the relative rotation angle between the fixed plate 53 and the rotary plate 54 detected in step 1 is processed by an electric circuit (not shown) and then digitally displayed on the digital display 5.

Next, the operation of this embodiment will be explained. When the ratchet thimble 36 or thimble 3 is rotated,
The inner cylinder 31, which is integral with the thimble 3, is displaced in the axial direction while rotating. Then, the spindle 4, which is axially abutted and supported by both ends of the inner cylinder 31 via the taper portion 12 and the taper receiving piece 16 and whose rotation is prevented by the screw 13 and the keyway 14, rotates. Displaces linearly.

At this time, the rotation of the inner cylinder 31, that is, the axial displacement of the inner cylinder 31, and the related axial displacement of the spindle 4 are detected by the encoder 51, and are digitally displayed on the digital display 5. be done. Therefore, by bringing the anvil 2 and spindle 4 into contact between the measurement parts of the workpiece and reading the value on the digital display 5 at that time, it is possible to know the dimensions between the measurement parts of the workpiece.

By the way, in adjusting the gap between the fixed plate 53 and the rotary plate 54, first loosen the set screw 45. Then, the spring 44 urges the collar 43, spacer 42, and rotating cylinder 41 to the right in FIG.
It comes into contact with the end face of the second small diameter cylindrical portion 22A. At this time, the gap between the fixed plate 53 and the rotating plate 54 becomes a reference value (the minimum allowable clearance between the fixed plate 53 and the rotating plate 54).

In this state, the screws 48A and 48B are tightened to integrally fix the rotating cylinder 41 and the inner cylinder 31. At this point, the ratchet thimble 36 or thimble 3 is turned to send the inner cylinder nut 31 and spindle 4 a predetermined amount to the left in FIG. At this time, the feed amount of the spindle 4 can be determined while checking the values of the main scale scale 37 and the vernier scale scale 38, so that the gap between the fixed plate 53 and the rotary plate 54 can be quantitatively determined within the allowable clearance. be able to. Thereafter, the set screw 45 is tightened to fix the collar 43 to the bearing sleeve 11, that is, the collar 43 is fixed to the frame 1 via the bearing sleeve 11.

In this way, during use, the gap between the fixed plate 53 and the rotary plate 54 varies between the reference gap and the maximum gap (reference gap + set clearance), which does not affect measurement accuracy and ensures smooth measurement. Rotation is guaranteed.

Therefore, according to this embodiment, the rotation of the thimble 3 or the ratchet thimble 36 causes the inner cylinder 31 to open.
This inner cylinder 3 is moved forward and backward in the axial direction while rotating.
1, the spindle 4 moves straight without rotating by moving back and forth in the axial direction of the encoder 1, and the rotary plate 54 of the encoder 51 is rotated relative to the fixed plate 53 by rotating the inner cylinder 31. As a result, the spindle 4 can be of a straight type while maintaining a compact size. Therefore, even objects to be measured having narrow grooves such as spline shafts can be easily and accurately measured.

Furthermore, since the spindle 4 is supported by the inner cylinder 31 by the taper portion 12 and the taper piece 16 that are provided at a relatively long distance along the axial direction, even if the stroke of the spindle 4 is large, Straightness and parallelism of the measurement surface can be ensured during movement of the spindle 4, thereby achieving high precision measurement.

In addition, the inner cylinder 31 is connected to the large diameter cylinder part 31A and the small diameter cylinder part 3.
1B are combined with each other, so the inner cylinder 31
Since it is possible to process and assemble with high precision and also to easily center both ends of the inner cylinder 31, the spindle 4 can be stably supported with high precision.

Further, since the bearing tube 11 is made to protrude toward the anvil 2 side and the support portion of the spindle 4 is widened, the straightness of the spindle 4 during movement and the parallelism between the measurement surfaces can be ensured from this point as well.

In addition, since the gap between the fixed plate 53 and the rotary plate 54 that constitute the encoder 51 can be adjusted from the standard gap within an allowable range, there is no need for the high precision machining of each component as in the past. As a result, it can be done economically.

Furthermore, when adjusting the gap between the fixed plate 53 and the rotary plate 54, the inner cylinder 31 and the spindle 4 only have to be moved in the axial direction by rotating the thimble 3, so the adjustment work is extremely easy. . Moreover, since the feed of the spindle 4 can be performed by reading the main scale scale 37 and the vernier scale scale 38, the feed amount can be determined quantitatively.

Further, since the wear between the end face of the small diameter cylindrical portion 22A of the inner sleeve 22 where the fixed plate 53 is located and the end face of the rotating cylindrical body 41 to which the rotary plate 54 is fixed is reduced, handling problems can be solved. can.

In addition, when attaching the fixing plate 53 to the plate 52, if the retaining ring 21 is adjusted to be threaded onto the frame 1, the fixing plate 53 and the small diameter cylindrical part 22A
Since the reference gap between the end face and the end face can be adjusted, it is easy to adjust the reference gap.

Further, since the collar 43 and the spacer 42 are divided into two, they can be easily taken out by removing the spindle 4 during disassembly.

In addition, in implementation, the encoder 51 is not limited to the capacitance type described in the above embodiment, but may be of any type, such as a photoelectric type, an electromagnetic type, or a contact type.

Further, in the above embodiment, a reference gap is formed between the surface of the fixed plate 53 facing the rotating plate 54 and the end face of the small diameter cylindrical portion 22A of the inner sleeve 22. A predetermined ratio, for example, 1/2, between the surface and the end face of the rotating cylinder 41, between the fixed plate 53 and the end face of the small diameter cylinder part 22A, and between the rotating plate 54 and the end face of the rotating cylinder 41, respectively. It is also possible to provide one for each.

[Effect of idea]

As described above, according to the present invention, it is possible to provide a compact and highly accurate linear digital display type micrometer.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a partially cutaway front view of the entire device, and FIG. 2 is a plan view showing the abutting end of the anvil and the spindle. 1... Frame as main body, 2... Anvil, 3... Thimble, 4... Spindle, 5...
Digital display, 12... Taper part, 16... Taper receiving piece, 22A... Small diameter cylinder part, 31... Inner cylinder,
31A...Large diameter cylinder part, 31B...Small diameter cylinder part, 41
... Rotating cylinder, 43 ... Collar, 44 ... Spring as biasing means, 51 ... Encoder, 53 ...
Fixed plate, 54...rotating plate.

Claims (1)

[Claims for Utility Model Registration] (1) A main body having an anvil at one end, and a pair of non-rotatable but movable displaceable in the axial direction of the anvil at the other end of the main body, located at a predetermined interval apart in the longitudinal direction. A spindle having a tapered portion; and the spindle is rotatably fitted with both ends in contact with the tapered portion of the spindle, and is screwed into a threaded portion formed in the main body along the axial direction of the spindle. and an inner cylinder that rotates integrally with the thimble, a rotary plate that is provided to be rotatable in synchronization with the inner cylinder and not displaceable in the axial direction of the inner cylinder, and fixed to the main body with a constant gap with the rotary plate. and a digital display that digitally displays a measured value based on an output signal of the encoder. Features a linear digital display micrometer. (2) Utility model registration In the linear digital display type micrometer according to claim 1, the fixed plate and rotating plate of the encoder can be rotated synchronously with the end face of the small diameter cylindrical portion of the main body and the inner cylinder. and are attached to the main body and the rotary cylinder so that the gap in the axial direction between the two plates is constant when the end surfaces of the rotary cylinder which are fixedly fitted are brought into contact with each other, and A linear digital display type, comprising a collar that is fitted into the inner cylinder and can be integrally fixed to the main body, and a biasing means for biasing the collar and the rotary cylinder toward the fixed plate. Micrometer. (3) In the linear digital display type micrometer according to claim 1 or 2 of the utility model registration claim, the inner cylinder has a large-diameter cylinder part screwed into the main body, and the rotary plate is engaged with the inner cylinder. A linear digital display type micrometer characterized in that a matching small-diameter cylindrical portion is connected to each other. (4) A linear digital display type micrometer according to any one of claims 1 to 3 of the utility model registration claim, characterized in that the abutting ends of the anvil and the spindle are blade-shaped. Digital display type micrometer.