JPS6044604B2 - electronic micrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic micrometer, and particularly relates to a fixed scale fixed to a frame, a spindle whose tip comes into contact with an object to be measured during measurement, and a micrometer that interlocks with the spindle. Improvement of an electronic micrometer that is equipped with a movable scale and measures the length of an object to be measured held between a frame and a spindle based on the change in physical quantity between the movable scale and the fixed scale due to the displacement of the spindle. Regarding.

A micrometer is a type of length measuring device that measures the length of an object to be measured.

This device has a frame and a spindle whose tip comes into contact with the object to be measured during measurement, and measures the length of the object held between the frame and the spindle from the displacement of the spindle. Conventionally, so-called mechanical micro-controllers were used to read the position of the spindle relative to the frame based on the feed amount of a precisely machined screw formed at the rear end of the spindle, using magnification due to the slope of the screw. Meters are mainly used. On the other hand, in recent years, with the advancement of electronics, so-called electronic micrometers have been proposed in which the dimension reading portion of mechanical micrometers is replaced with a photoelectric detection device.

This includes, for example, a fixed scale fixed to a frame and a movable scale linked to a spindle, and changes in physical quantities between the movable scale and the fixed scale due to the displacement of the spindle, such as the amount of passing light or the amount of reflected light. The length of the object to be measured held between the frame and the spindle is measured from the change in . Although such electronic micrometers enable more accurate measurements than conventional mechanical micrometers, conventionally there have been some problems with their operational feel. In other words, conventional electronic My. In a chromator, in order to keep the measurement pressure constant, the measurer had to hold the spindle at a constant pressure so that a predetermined measurement pressure was applied. On the other hand, in an electronic micrometer, in order to prevent the spindle from returning freely and to keep the measurement force constant, a reciprocating mechanism is used to reciprocate the spindle over the entire stroke, and the reciprocating mechanism can be moved to any position. It is conceivable to provide a ratchet mechanism for locking the spindle and a constant pressure mechanism for pressing the spindle against the object to be measured with a constant measuring force when the ratchet mechanism is in operation. If the ratchet mechanism is operated all the time, the claws of the ratchet mechanism will run over the rack when the spindle moves, resulting in so-called ratcheting noise.

This is because when a conventional mechanical micrometer is rotated, no rotational noise is generated until the spindle comes into contact with the object to be measured. The ratcheting sound is louder than the ratcheting sound that occurs after the spindle contacts the object to be measured, and its commercial value is low. The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and provides an electronic micrometer that does not generate ratchet noise until the spindle contacts the object to be measured and when the spindle retreats. With the goal.

The electronic micrometer according to the present invention includes a fixed scale fixed to a frame, a spindle whose tip is brought into contact with an object to be measured during movement measurement in conjunction with a slide knob that is an operation section, and a spindle that is coupled with the spindle. An electronic micrometer that measures the length of an object to be measured held between a frame and a spindle based on changes in physical quantities between the movable scale and the fixed scale due to the displacement of the spindle. , a reciprocating mechanism for reciprocating the spindle over the entire stroke, a ratchet mechanism for locking the reciprocating mechanism at an arbitrary position, and pressing the spindle against the object to be measured with a constant measuring force. and a ratchet operating mechanism for operating the ratchet mechanism between when the spindle contacts the object to be measured and when the constant pressure mechanism completes its operation. The reciprocating mechanism includes a slider that is coupled to the spindle by the action of a measuring force imparting spring that presses the spindle in a direction in which it comes into contact with the object to be measured, and that moves in the same direction as the spindle movement direction; The constant pressure mechanism is configured by the measuring force applying spring and the slider, and the ratchet mechanism is connected to a guide shaft fixed to the frame in parallel with the spindle. The ratchet actuating mechanism includes a rack formed in the slide knob, and a pawl arm that is interlocked with the slide knob and has a pawl that engages with the rack to lock the slider at a desired position. , a claw biasing spring for constantly biasing the claw in a direction in which the claw engages with the rack when the spindle comes into contact with the object to be measured; A cam plate formed on the scale holder fixed to the spindle and retraction of the slider by the slide knob for biasing the claw arm in the opposite direction to the claw biasing spring to release the engagement between the rack and the claw. When the slide knob is pressed, the claw arm is biased in a direction opposite to the claw biasing spring, and is movable relative to the slider within a predetermined range to release the engagement between the rack and the claw. It is characterized by comprising an intermediate plate to which the slide knob is fixed, which biases the claw arm in the opposite direction to the claw biasing spring to release the engagement between the rack and the claw, This achieves the above objective.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 1 to 5, this embodiment includes a substantially U-shaped frame 10 with an anvil 12 disposed inside the tip, and two guides installed on the rear end surface of the frame 10. axis 1
4, 16, and a holder 18 fixed to the rear end of the guide shafts 14, 16, with a light transmitting part and a non-light transmitting part on a glass flat plate, which is a fixed scale, which is fixed via a light receiving board 20. an index scale 22 in which portions are formed in a striped pattern at equal intervals; a spindle 24 that is supported in a relatively movable state with respect to the frame 10 and whose tip 24a abuts the object to be measured during measurement; A main scale 28 is a movable scale whose front end is fixed to a scale holder 26 fixed to a spindle 24, and is composed of a flat plate made of glass, on which light transmitting parts and non-transmissive parts are formed in a striped pattern at equal intervals. , a light source 32 disposed on a light source substrate 30 fixed to the holder 18; and light emitted from the light source 32 disposed on the light receiving substrate 20 and transmitted through the main scale 28 and the index scale 22; The anvil 12 of the frame 10 and the spindle 2 are equipped with a light receiving element 34 that receives light from the anvil 12 of the frame 10 and the spindle 2 from changes in the amount of light passing between the main scale 28 and the index scale 22 due to the displacement of the spindle 24.
In the electronic micrometer for measuring the length of a measured object held between the tips 24a of the spindle 24
is rotated by a measuring force imparting spring 36 and a pin 39 that move in the same direction as the moving direction of the spindle 24 and press the spindle 24 in the direction of contacting the object to be measured. By the action of the freely supported connecting arm 38, the slider 40 is connected to the lower end of the scale holder 26 fixed to the spindle 24, and the slider 40 is connected to the index scale 2.
2. A reciprocating mechanism consisting of a slide knob 44 for operating from the outside of the case 42 that covers the main scale 28 etc., and the frame 10 in parallel with the spindle 24 for locking the reciprocating mechanism at an arbitrary position. a rack 16a formed on the guide shaft 16;
It is rotatably supported by a pin 48 fixed to the slider 40, which has a claw 46a for engaging with the rack 16a and locking the slider 40 at a desired position;
A ratchet mechanism consisting of a pawl arm 46 interlocked with the slide knob 44, the measuring force applying spring 36, the connecting arm 38, and a slider for pressing the spindle 24 against the object to be measured with a constant measuring force. 40, and a ratchet operating mechanism for operating the ratchet mechanism when the constant pressure mechanism is activated. The ratchet actuation mechanism moves the pawl arm 46 between its pawls 4 and 4, as shown in detail in FIGS. 5 through 8.
6a engages with the rack 16a (counterclockwise in FIG. 5), and when the spindle 24 abuts the object to be measured, a slider for causing the pawl 46a to engage with the rack 16a. When the slider 40 is moved forward by the slide knob 44, the claw biasing spring 50 interposed between the claw biasing spring 50 and the front end of the claw arm 46 moves the claw arm 46 in a direction opposite to that of the claw biasing spring 50 (as shown in FIG. A substantially inverted L-shaped cam plate 256a (clockwise) formed at the lower end of the scale holder 26 fixed to the spindle 24 for disengaging the rack 16a from the claw 46a. 6), and a protrusion 46b formed on the upper surface of the front end of the melon arm 46 and having a slope 46c formed on the rear side, and the slide knob 44 at the rear end of the slider 40. Relative movement with respect to the slider 40 within a predetermined range to bias the claw biasing spring 50 in the opposite direction (clockwise in FIG. 6) and release the engagement between the rack 16a and the claw 46a. an intermediate plate 56 (see FIG. 7) to which the slide knob 44 is fixed;
6 in the forward direction at all times, and has a substantially U-shaped leaf spring 58, one end of which is fixed to the slider 40.

The action will be explained below.

First, in a state before starting measurement in which the tip end 24a of the spindle 24 is sufficiently retreated with respect to the frame 10, the claw arm 46 is urged counterclockwise in FIG. 5 by the action of the claw biasing spring 50. The claw 46a of the claw arm 46 and the rack 16a are in mesh with each other. Also, at this time, due to the action of the measuring force applying spring 36, the connecting arm 38
is biased clockwise in FIG. 4 around pin 39,
As shown by the solid line in FIG. 4, the slider 40 is in a state integrated with the scale holder 26. At this time, when the slide knob 44 is moved to the left in FIG. 5 with the claw 46a of the claw arm 46 engaged with the rack 16a and the spindle 24 is advanced, the claw 46a is engaged with the rack 16a.
A ratcheting sound is generated when the product is overcome, and the product value is inferior. Therefore, in the present invention, this ratchet sound is eliminated. That is, when the measurer moves the slide knob 44 fixed to the intermediate plate 56 in the forward extension direction (arrow A direction) to sandwich the object to be measured between the anvil 12 of the frame 10 and the tip 24a of the spindle 24, As shown in FIG. 7, the pin 4 fixed to the slider 40
8 and the stopper pin 54 are both located in an I-shaped cam hole 56a.8 formed in the intermediate plate 56. ．． While engaged with the rear end of the L-shaped cam hole 56b, the slider 40 and the measuring force applying spring 3
6, the scale holder 26 is integrated with the slider 40, and the scale holder 26 is integrated with the slider 40 by the . The spindle 24 fixed to the scale holder 26 starts moving forward.

At this time, as shown in FIG. 5, the front end portion of the cam plate 26a formed on the scale holder 26
A state in which the protrusion 46b formed on the front end of the 6 is engaged with the slope 46c! Therefore, the claw arm 46 is rotated clockwise in FIG. 5 against the claw biasing spring 50, and the engagement between the claw 46a and the rack 16a is released. Therefore, no ratchet noise is generated when the spindle moves forward.
4 On the other hand, when the spindle 24 is sufficiently advanced and its tip 24a comes into contact with the object to be measured, the spindle 24 stops advancing, while the slider 40 is urged in the forward direction by the slide knob 44. Therefore, the connecting arm 38 is rotated counterclockwise (in the direction of arrow B) in FIG. 4 against the measuring force applying spring 36, resulting in the state shown by the dashed line C. At this time, the scale holder 26 is retracted from the slider 40 by the relative movable range D (FIG. 4) between the slider 40 and the scale holder 26, which is set by the slider 40. The engagement relationship between the cam plate 26a formed on the cam plate 26a and the slope 46c formed on the pawl arm 46 is released, and the pawl arm 46 moves around the pin 48 as shown in FIG. is rotated counterclockwise, and the claw 46a becomes engaged with the rack 16a. At this time, the range of rotation of the claw arm 46 is restricted by a screw 54 that acts as a stopper and comes into contact with the inner wall of a hole 46f formed in the claw arm 46. Therefore, the free return of the slider 40 is prevented, and the length of the object to be measured is measured with an effective measuring force being applied to the spindle 24 by the measuring force applying spring 36. That is, the length of the object to be measured held between the anvil 12 of the frame 10 and the tip 24a of the spindle 24 is determined from the change in the amount of light passing between the main scale 28 and the index scale 22 due to the displacement of the spindle 24 from the reference position. is measured electrically. When the measurement is completed and the spindle 24 is opened to remove the object to be measured, the slide knob 44 is first moved back slightly (in the direction of arrow E) and then pressed (in the direction of arrow F).

Then, the intermediate plate 56 to which the slide knob 44 is fixed,
It first retreats in the direction of arrow E against the leaf spring 58, and then
It is pressed in the direction of arrow F and rotated clockwise in FIG. 7 about pin 48 until the inner wall of cam hole 56b abuts stopper pin 54. Then, the claw arm 46 is also rotated clockwise in FIG. 7 about the pin 48 by the protrusion 46d formed on the lower surface of the tip of the claw arm 46.
The engagement between the pawl 46a and the rack 16a is released, and the spindle 24 is retracted without producing ratchet noise.
Note that the protrusion 46 formed on the lower surface of the tip of the claw arm 46
d and a protrusion 46 formed on the lower surface of the rear end of the claw arm 46.
e functions as a spacer to maintain a predetermined distance between the upper surface of the slider 40 and the lower surface of the claw arm 46 to allow the intermediate plate 56 to slide freely. In the above embodiment, the ratchet operation mechanism that operates the ratchet mechanism was set to operate when the constant pressure mechanism was operated, but the timing at which the ratchet operation E mechanism is operated is not limited to this, and when the spindle is covered. It does not matter as long as it is from the time it comes into contact with the object to be measured until the constant pressure mechanism completes its operation.

In the above embodiment, the present invention was applied to an electronic micrometer in which the index scale 22 was fixed and the main scale 28 was movable, but the scope of application of the present invention is not limited to this, and the index scale 22 is fixed and the main scale 28 is movable. It is clear that the present invention can be similarly applied to a movable electronic micrometer. Further, in the embodiment, the present invention provides the main scale 28 and the index scale 22.
The present invention has been applied to electronic micrometers that measure the displacement of a measurement target from changes in the amount of light passing between the main scale and index scale, but the scope of application of the present invention is limited to this. It is clear that the invention can be similarly applied to electronic micrometers that measure the displacement of an object, or general electronic micrometers that measure the displacement of a spindle from changes in other physical quantities between the main scale and the index scale. .

Further, in the above embodiment, the present invention was applied to an electronic micrometer, but the scope of application of the present invention is not limited thereto, and can be similarly applied to other length measuring instruments such as calipers and height gauges. The applicability is clear.

As explained above, according to the present invention, the ratcheting sound until the spindle contacts the object to be measured and when the spindle retreats is eliminated, and the same operational feeling as a conventional mechanical micrometer is obtained. Furthermore, according to the present invention, the ratchet mechanism can be actuated and deactivated simply by operating the slide knob, which is the operation part for reciprocating the spindle, making measurement work, especially for long periods of time, easier. This method is effective for continuous measurement of objects to be measured that vary greatly in temperature.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of an electronic micrometer according to the present invention, FIG. 2 is a cross-sectional view taken along line 1--2 in FIG. 1, and FIG. 4 is a rear view showing the main parts of the embodiment, FIG. 5 is a top view showing the ratchet mechanism and the ratchet operating mechanism in the embodiment, and FIG. 6 is a sectional view taken along the line. FIG. 7 is a side view showing the shape of the scale holder used in the example, FIG. 7 is a top view showing the pawl arm and intermediate plate of the ratchet mechanism and ratchet actuation mechanism, and FIG. FIG. 3 is a front view showing the relative positional relationship between the plate and the slider. 10... Frame, 14, 16... Guide shaft, 16a... Rack, 18... Holder, 20... Light receiving board, 22... ...Index scale, 24...End spindle, 26...
・Scale holder, 26a...Cam plate, 28...
...Main scale, 30...Light source board, 3
2... Light source, 34... Light receiving element, 36
...Measuring force imparting spring, 38...Connection arm, 4
0...Slider, 44...Slide knob,
46...Claw arm, 46a...Claw, 50.
...Claw biasing spring, 56...Intermediate plate.

Claims (1)

[Claims] 1. A fixed scale fixed to a frame, a spindle whose tip is brought into contact with the object to be measured during movement measurement in conjunction with a slide knob that is an operation section, and a movable scale interlocked with the spindle. In an electronic micrometer that measures the length of an object to be measured held between a frame and a spindle from changes in physical quantities between a movable scale and a fixed scale due to displacement, the spindle is reciprocated over its entire stroke. a reciprocating mechanism for locking the reciprocating mechanism at an arbitrary position; a constant pressure mechanism for pressing the spindle against the object to be measured with a constant measuring force; During the period from when the constant pressure mechanism comes into contact with the constant pressure mechanism to the time when the constant pressure mechanism completes its operation,
The electronic micrometer is equipped with a ratchet operating mechanism for operating the ratchet mechanism, and the reciprocating mechanism is operated by the action of a measuring force applying spring that presses the spindle in a direction in which it comes into contact with the object to be measured. It is composed of a slider coupled to the spindle and moved in the same direction as the spindle movement direction, and the slide knob for operating the slider, and the constant pressure mechanism is constituted by the measuring force applying spring and the slider. , the ratchet mechanism includes a rack formed on a guide shaft fixed to the frame in parallel with the spindle, and a pawl that engages with the rack to lock the slider at an arbitrary position. and a pawl arm interlocked with a knob. a claw biasing spring for engaging the rack with the rack; and a claw biasing spring for biasing the claw arm in a direction opposite to the claw biasing spring when the slider is moved forward by the slide knob to release the engagement between the rack and the claw.
When the slider is retracted by a cam plate formed on a scale holder fixed to the spindle and the slide knob, the claw arm is biased in a direction opposite to the claw biasing spring to release the engagement between the rack and the claw. is movable relative to the slider within a predetermined range, and biases the pawl arm in a direction opposite to the pawl biasing spring when the slide knob is pressed;
An electronic micrometer comprising an intermediate plate to which the slide knob is fixed and which releases the engagement between the rack and the claw.