JPH0243122B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a digital camera that electrically measures the amount of movement of a moving body using a fixed scale provided on a frame body and a moving scale provided on the moving body and opposed to the fixed scale. The present invention relates to a length measuring device, and particularly to a method for manufacturing a spacer provided between a fixed scale and a moving scale in order to maintain the parallelism between the fixed scale and the moving scale more accurately and at a minute interval.

In general, accuracy errors in digital length measuring instruments that electrically measure the amount of movement of a moving object using a light-emitting element and a light-receiving element by arranging a fixed scale provided on a frame and a moving scale provided on a moving object to face each other are large. There are errors caused by electrical factors and errors caused by mechanical factors.

Errors caused by electrical factors include errors caused by digitizing the output signal of the light-receiving element, return errors caused by hysteresis voltage intentionally applied to the output signal of the light-receiving element to prevent display values from flickering, etc. .

Errors due to mechanical factors include errors in scale units that occur during the scale manufacturing process, installation errors between a fixed scale and a movable scale, errors due to deviations in parallelism of scales, errors due to changes in scale gaps, etc.

Errors caused by electrical factors are extremely small compared to errors caused by mechanical factors, and can be further reduced by providing a compensation circuit or the like.

Also, among mechanical factors, errors that occur during manufacturing and installation can be estimated to a certain extent in advance, so errors can be reduced by further improving the accuracy of parts where errors are likely to occur or by conducting thorough quality inspections, etc. can be reduced.

However, deviations in the parallelism of the scale and changes in the scale gap occur not only due to errors in each part and installation, but also due to the use of the length measuring device, and it is extremely difficult to maintain accuracy.

If the parallelism of the scales and the scale gap are not maintained accurately, the amount of light received by the light receiving element that receives the light from the light emitting element passing through the pair of scales will change, resulting in errors.

The scale gap is generally kept at 0.01mm to 0.05mm, but the narrower and more uniform it is, the better the accuracy will be.

The object of the present invention is to obtain a uniform and very narrow scale gap and to improve the accuracy of scale parallelism by printing organic ink or inorganic ink on a fixed scale and baking it to provide a spacer.

Typical digital length measuring devices include digital dial gauge, digital micrometer,
There are digital height gauges, etc., and embodiments of the present invention will be described below with reference to the drawings, taking a digital dial gauge as an example.

FIG. 1 is an explanatory view of essential parts of a digital dial gauge, and FIG. 2 is an enlarged cross-sectional view taken along line A-A of the explanatory view shown in FIG.

1 is a frame made of metal material such as aluminum or brass;
A spindle 2 is supported by an upper bush 3 and a stem 4 so as to be slidable up and down, and a coil spring 5 is attached at one end to the frame 1 and at the other end to a spring hanging pin 6 fixed to the spindle 2.

The spindle 2 is constantly urged downward by this coil spring 5. 7 is a guide rod, one end of which is fixed to the spindle 2, and the other end of which is fixed to the frame 1.
The guide groove 1a is inserted into the guide groove 1a provided in the guide groove 1a.

This guide rod 7 is provided to restrict rotation of the spindle 2 during the movement process. 8 is a measurement terminal provided at the lower end of the spindle 2. 9 is a moving scale mounting plate fixed to the spindle 2 with screws or adhesive, 10 is a moving scale that is adhesively fixed to the moving scale mounting plate 9 and has a known lattice pattern, and 11 has a known lattice pattern. The scale is a fixed scale, and a spacer 12 is formed on the surface of the scale by printing and firing to obtain a scale gap with the movable scale 10.

This fixed scale 11 is bonded to an elastic member 13 such as a leaf spring fixed to the frame 1, and is supported in a cantilevered manner via the elastic member 13.

14 is a fixed scale 11 screwed to the frame body 1;
A receiver 16 that extends downward and holds a pressing elastic member 15 such as a spring is a light emitting element mounting plate that supports a light emitting element 17, and is fixed to the frame 1 with screws 18.

Reference numeral 19 denotes a light receiving element plate that supports the light receiving element 20 and is screwed together with the receiving plate 14 to the frame 1.

The light emitting element 17 and the light receiving element 20 are arranged opposite to each other so as to sandwich the scale.

In this embodiment, the fixed scale 11 is always elastically pressed against the movable scale 10 by the action of the elastic member 13 and the pressing elastic member 15, so that the fixed scale 11 is structured to follow the movement of the movable scale 10. There is.

In the above configuration, the movable scale 10 and the fixed scale 11 are kept parallel to each other by the action of the spacer 12.

FIG. 3 is a BB sectional view of the enlarged sectional view shown in FIG. 2.

The elastic member 13 is U-shaped, and has an arm portion 13a.
The fixed scale 11 is held at . Further, four spacers 12 are provided on the surface of the fixed scale 11.

This spacer 12 is printed and fired with organic or inorganic ink. The steps for forming the spacer 12 are listed below.

Step 1 Spacer formation step using organic ink (1) Degrease and clean the fixed scale formed of glass material with Triclean for about 10 minutes.

(2) Dry the fixed scale with warm air (about 60℃, about 10 minutes).

(3) Print epoxy ink on the desired position on the surface of the fixed scale. In this case, Cemedine 1565, Epicote 828, or Araldite (trade name) is used as the epoxy ink.

(4) Baking the printed epoxy ink (approximately 80℃,
approximately 30 minutes).

(5) The epoxy ink fired in step 4 is further fired (approximately 150°C, approximately 60 minutes).

(6) Clean the fixed scale.

(7) Dry with warm air.

Step 2 Other spacer formation steps using organic insulator (1) A fixed scale made of glass material,
Degrease and clean with Triclean for about 10 minutes.

(2) Dry with warm air (about 60℃, about 10 minutes).

(3) Print epoxy ink on the desired position on the surface of the fixed scale. In this case, the epoxy ink is Cemedine 1565, Epicote 828 or Araldite (trade name) with 10μ glass beads, 5
Use one or both of ~10μ glass fibers mixed in. This is to improve wear resistance.

(4) Baking the printed epoxy ink (approximately 80℃,
approximately 30 minutes).

(5) Bake again (approximately 150℃, approximately 60 minutes).

(6) Clean the fixed scale.

(7) Dry with warm air.

Step 3 Spacer formation step using inorganic ink (1) Degrease and clean the fixed scale formed of glass material with Triclean for about 10 minutes.

(2) Dry with warm air (about 60℃, about 10 minutes).

(3) Print inorganic ink at a desired position on the surface of the fixed scale. In this case, low melting point glass (solder glass paste) is used as the inorganic ink.

(4) Baking the printed inorganic ink (approximately 400℃~500℃)
℃, approximately 10-30 minutes).

(5) Cleaning (6) Dry with warm air.

As detailed above, the fixed scale of the present invention is elastically held, so it can follow any movement of the moving scale, and the spacer printed on its surface keeps the scale gap with the moving scale accurate at all times. Since the spacer is formed by printing, the position and thickness of the spacer can be easily selected and determined.

In particular, according to the spacer manufacturing method of the present invention, 10
Not only is it easy to select a minute scale gap of ~5 μ, but it is also lightweight and has excellent durability.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view of essential parts of a digital dial gauge, FIG. 2 is an enlarged cross-sectional view taken along line AA of the explanatory view shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B of FIG. 2. DESCRIPTION OF SYMBOLS 1... Frame body, 2... Spindle, 9... Moving scale mounting plate, 10... Moving scale, 11...
Fixed scale, 12... Spacer, 13... Elastic member, 14... Receiver, 15... Elastic member for pressing,
16... Light emitting element mounting plate, 17... Light emitting element, 1
8... Screw, 19... Light receiving element plate, 20... Light receiving element.

Claims (1)

[Claims] 1. A spacer for obtaining a scale gap between a fixed scale provided on a frame and a movable scale provided on a movable body, and a light emitting element and a light receiving element disposed facing each other so as to sandwich the pair of scales. In the digital length measuring device which electrically detects the amount of movement of the moving body, the spacer is formed on the surface of the fixed scale by printing with either organic ink or inorganic ink and baking. A method for manufacturing a spacer in a digital length measuring device, characterized in that: 2. The digital length measuring device according to claim 1, wherein the organic ink is printed and fired by mixing one or both of 0.01 mm glass beads and 0.005 to 0.01 mm glass fibers. Method of manufacturing spacers.