JPS641110Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for attaching a member to a drafting head for detecting the rotation angle of the drafting head by electronic means.

In recent years, electronic means have been used to detect the rotation angle of the drafting head of a drafting machine used for manual drafting work on a drawing board, and to detect the entire detected rotation angle or less than the degree scale. Devices incorporating devices that display only the minute scale by electrical or electronic means have begun to appear.

The above device includes an optical encoding disk for converting the amount of rotation of the drafting head into a periodic sinusoidal electric signal, and a scale attached to the drafting head above and below the optical encoding disk. An optical rotation angle detection member running in a constant angular relationship is incorporated.

The positioning adjustment of the rotational angle detection member with respect to the optical encoding disk requires extremely high accuracy, for example, in an apparatus that displays rotational angles down to the minute scale. This positioning adjustment of the rotation angle detection member is mainly divided into two aspects. That is, one side thereof is such that when the angle of the horizontal scale coincides with its zero position on the degree scale of the protractor, the rotation angle detection member also comes to rest at a point coincident with its zero position on the optical encoding disk. This is zero position adjustment.

Another aspect of the present invention is that a plurality of rotation angle detection elements arranged at a certain interval and with a certain mutual positional relationship in the rotation angle detection member are arranged radially inwardly or outwardly of the optical encoding disk. In order to prevent a situation in which the expected phase difference is not obtained between the electrical signals output from each rotation angle detection element due to traveling on a shifted trajectory, the rotation angle detection member is connected to the optical encoding disk. This is a phase adjustment that positions the vehicle so that it travels on a scheduled trajectory.

An object of the present invention is to provide a rotation angle detection member mounting device for a drafting head that does not require the above-mentioned phase adjustment and also allows easy zero position adjustment. To achieve this purpose, the present invention consists of a cylindrical handle shaft that stands perpendicular to the drawing board and is freely rotatable, and a protractor that is selectively integrated with the handle shaft and has a degree scale. , install the straightedge,
In addition, a drafting head board fixed to the lower end of the handle shaft, a coding disk fixed in a fixed positional relationship to the protractor, and a drafting head board integrally facing the coding disk. In the drafting head which is equipped with a rotation angle detection member which is rotated while rotating, the rotation angle detection member is fixed to the tip of the support plate and a proximal annular portion is provided on the proximal end side of the support plate. This proximal annular portion is fitted onto the handle shaft so that the peripheral wall surface of the hole can freely slide on the outer peripheral surface of the handle shaft, and a long length in the horizontal axis direction of the support plate is inserted in the middle of the support plate. The present invention is characterized in that a hole is provided and the support plate is screwed to the drafting head board in an adjustable manner using screws inserted through the long hole.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3. Drafting head 1
is a connecting member equipped with a hinge mechanism on a vertical rail (not shown) that moves horizontally on the drawing board along a horizontal rail (not shown) attached to the upper edge of the drawing board (not shown). (not shown). This drawing head 1 can be moved over the drawing board along a longitudinal rail.

At the center of the drafting head 1, a knob (not shown) is fixed to the upper end of a cylindrical handle shaft 2 that stands perpendicular to the drafting board. This knob allows the operator to move the entire drawing head 1 to any point on the drawing board or to rotate the handle shaft 2. An outward flange 3 is formed at the lower end of the handle shaft 2, and a drafting head board 4 is disposed in contact with the lower surface of the outward flange 3. This drafting head board 4 is screwed onto the outward flange 3 with screws 5. has been done. This drafting head board 4 is formed with a ruler attachment part 6 for attaching a straightedge (not shown), and a long and thin support plate 8 with a rotation angle detection member 7 fixed to its tip is attached using two screws. It is screwed by 9 and 10. These screws 9 and 10 are screwed into screw holes 9a and 10a provided in the drafting head board 4. screws 9 and 1
Elongated holes 9b and 10b which are long in the horizontal axis direction of the support plate 8 (to the extent that they can be moved by ±2 degrees) are formed on the side of the support plate 8 through which the 0 is inserted.

A proximal annular portion 11 is formed on the proximal end side of the support plate 8 . This proximal annular portion 11 is externally fitted onto the handle shaft 2. The support plate 8 is rotated integrally with the drafting head base plate 4 in a state in which the circular hole circumferential wall surface 11a of the proximal annular portion 11 slides on the outer circumferential surface of the handle shaft 2.

When screws 9 and 10 are loosened, the elongated hole 9
The support plate 8 can rotate a slight amount with respect to the drafting head board 4 within the widths of b and 10b, using the handle shaft 2 as a rotation reference, thereby making it possible to adjust the zero position of the rotation angle detection member 7. becomes.

The drafting head board 4 includes a drafting head board 4.
An elongated ratchet wheel operating plate 12 that is movable in the longitudinal direction is slidably disposed.

The handle shaft 2 is fitted into a non-rotatable bearing 13 so as to be rotatable. This bearing metal 13 is supported by the above-mentioned connecting member in an unrotatable state. Thick outward flanges 14 and 15 are formed at the upper and lower ends of the bearing metal 13. The bearing metal 13 is connected to the connecting member at the upper outward flange 14, and an annular fixed plate 17 for appropriately fixing the protractor plate 16 is fixed to the lower outward flange 15 by screws 18. There is.

The aluminum alloy protractor board 1 is placed in a state in which almost a part of the upper surface side is in sliding contact with the lower surface side of the fixed board 17.
6 is installed.

The protractor board 16 is provided with a 360° standard minute scale with a unit angle scale of 1°. When the ratchet wheel 19 comes into contact with the lower surface of the protractor 16, the screw 2
0 is fixed to the protractor board 16.

The ratchet wheel 19 is used to determine the stopping position of the drafting head board 4 at 15° intervals on the standard minute scale of the protractor board 16, and the ratchet wheel 19 has a number of tooth positions on the outer periphery thereof. is fixed to the protractor plate 16 so as to correspond to a constant angular position on the standard minute scale. Ratchet wheel 1
At 9, the claw member 21 provided at the tip of the ratchet wheel operation plate 12 is engaged and disengaged, so that the relative rotation between the protractor board 16 and the drafting head base plate 4 becomes possible or non-rotatable.

An annular groove 22 having a dovetail-shaped cross section is formed on the upper surface of the inner diameter side of the protractor plate 16, and a nut 24 in a fixed relationship with the protractor plate fixing lever 23 is screwed into the annular groove 22. The enlarged diameter head 26 of the matching bolt 25 is assembled. Since the bolt 25 is held in place by the fixed plate 17, when the protractor plate 16 is rotated, the groove wall surface of the annular groove 22 comes into sliding contact with the enlarged diameter head 26 of the bolt 25.

A ring attachment groove 27 having a rectangular cross section, opening downward, and an annular shape is formed on the lower surface side of the protractor 16 and near the outer periphery. A disk mounting ring 28 is arranged in this ring mounting groove 27. This disk mounting ring 28
is made of a stainless steel material having a coefficient of thermal expansion (=9.9 to 10.5×10 ⁻⁶ ) close to the coefficient of thermal expansion (=9×10 ⁻⁶ ) of the glass material constituting the optical encoding disk 29. . The inner diameter surface of the disk mounting ring 28 contacts the inner diameter side groove wall surface of the annular groove 22, the upper surface of the disk mounting ring 28 contacts the groove upper wall surface of the annular groove 22, and the outer diameter surface of the disk mounting ring 28 contacts the inner diameter groove wall surface of the annular groove 22. It is slightly away from the groove wall surface on the outer diameter side of the annular groove 22. Further, the disk attachment ring 28 is screwed onto the protractor plate 16 by a plurality of screws that are screwed together in the direction of its longitudinal axis.

An encoding disk 29 is externally inserted into the disk mounting ring 28, and the optical encoding disk 29 is inserted into the disk mounting ring 28.
Adhesive A is filled in spots at multiple locations between the inner diameter surface 29a of the disc mounting ring 28 and the outer diameter surface 28c of the disc mounting ring 28, and this adhesive allows the disc mounting ring 28 and the optical encoding disc 29 are joined. The inner diameter side upper surface of this optical encoding disk 29 comes into contact with the lower surface side outer peripheral edge of the protractor 16, so that the optical encoding disk 29
The levelness of the entire 9 is maintained.

As shown in FIG. 3, this optical encoding disk 29 has a large number of transparent slits 30 formed at an angular pitch of 1.degree. on its outer periphery. The opaque portions 31 adjacent to these slits 30 are formed by depositing chromium on the glass surface. A semicircular annular opaque portion 32 is formed by vapor deposition of chromium in a portion corresponding to the inner circumferential side of the many slits 30. A large number of slits 30 or opaque portions 31 are optical patterns for detecting angles in units of minutes smaller than the unit angle scale of the protractor 16, and semicircular annular opaque portions 32
is an optical pattern for detecting whether the horizontal scale attached to the drafting head board 4 is within the range of 0° to 180° or within the range of 180° to 360° on the protractor 16. . A rotation angle detection member 7 rotates integrally with the drafting head substrate 4 above and below these optical patterns.

As shown in FIG. 3, optical encoding disk 2
The zero position 33 at 9 is the semicircular annular opaque portion 3
This zero position 33 is located at the left end of the protractor 16.
The optical encoding disk 29 is fixed to the minute dial 16 so that it is located at a point slightly offset from the straight line connecting 0° and 180° on the minute scale.

As shown in FIG. 1, a minute display section 34 is provided on the surface side of the drafting head board 4 at a portion sandwiched between the ruler mounting section 6 and the protractor board 16. On the minute display section 34, minute scales in units of 5 minutes are written in Arabic numerals in the plus and minus directions of the scale of the protractor 16 with the zero position indicator 35 as the center. A total of 23 light emitting diodes 36 are arranged corresponding to the minute scale marked with these Arabic numerals. 0° in these light emitting diodes 36,
The light emitting diodes 36 indicating 10°, 20°, 30°, 40° and 50° are rectangular, and the light emitting diodes 36 indicating 5°, 15°, 25°, 35°, 45° and 55° are circular. It is. Any one of the 23 light emitting diodes 36 lights up as the drawing head board 4 rotates.

The rotation angle detected by the rotation angle detection member 7 is processed by an electronic circuit (not shown) built in the drafting head 1 and displayed by one of the light emitting diodes 36 in the minute display section 34. .

When adjusting the zero position of the rotation angle detection member 7, first align the zero position index 35 of the minute display section 34 with the zero position index of the protractor 16, and then loosen the screws 9 and 10. Support plate 8 is inserted into elongated holes 9b and 10.
The support plate 8 is moved within a width of b, and the support plate 8 is positioned with respect to the drafting head substrate 4 so that the light emitting diode 36 corresponding to 0 minutes lights up. Since the rotation angle detection member 7 is not displaced in the radial direction of the optical encoding disk 29 by the support plate 8, phase adjustment for adjusting the phase shift of the output signal is not necessary.

As described above, according to the present invention, the support plate is arranged around the handle shaft as the center of rotation, and the rotation angle detection member is fixed to this support plate, so there is no need for phase adjustment. Since the amount of movement in the circumferential direction can be large relative to the slit of the encoding disk, there is no need to make the attachment accuracy of the encoding disk too strict.

Furthermore, the rotation angle detection member can be disassembled while being fixed to the drafting head board, making repair and maintenance easy.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway plan view of a drafting head incorporating the rotation angle detection member mounting device of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is an optical encoding disk. FIG. 4 is an explanatory diagram of zero position adjustment between the rotation angle detection member and the rotation angle detection member. 1... Drafting head, 2... Handle shaft, 4...
Drafting head board, 7...Rotation angle detection member, 8...
...Support plate, 9 and 10...Screws, 9a and 10a
...Screw holes, 9b and 10b...Long holes, 11...
Base end annular portion, 11a...Circular hole peripheral wall surface, 16...
Protractor, 29...disk for optical encoding.

Claims (1)

[Scope of utility model registration request] A cylindrical handle shaft that stands perpendicular to the drawing board and is freely rotatable, a protractor that is selectively integrated with the handle shaft and has a degree scale, and a straightedge are attached. A drafting head board is fixed at the lower end, a coding disk is fixed in a fixed positional relationship with respect to the protractor, and the drawing head board is rotated and moved integrally with the drawing head board while facing the coding disk. The rotation angle detection member is fixed to the tip of a support plate, and a proximal annular portion is provided on the proximal end side of the support plate, The end annular portion is fitted onto the handle shaft so that the circumferential wall surface of the circular hole can slide freely on the outer circumferential surface of the handle shaft, and a long hole elongated in the horizontal axis direction of the support plate is provided in the middle of the support plate. A rotation angle detection member mounting device in which a support plate is screwed to the drafting head board so that the support plate can be attached and adjusted using screws inserted through the elongated holes.