JP2008232970A - Displacement measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement measuring device capable of easily adjusting the gap between a scale member and a light-receiving element. <P>SOLUTION: The displacement measuring device includes a body case 10, a spindle 20 built into the case 10 and axially movable, the scale member 30, having a structure with a scale-drawn on a glass scale 32 and mounted on the spindle 20, and a light-projecting element 40 and the light-receiving element 41 which are provided opposite, across the scale member 30 in the body case 10. The displacement-measuring device also includes a gap adjustment mechanism 50 for moving the light-receiving element 41, closer to or farther away from the scale member 30 for fine adjustment of the gap, between the scale member 30 and the light-receiving element 41. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a displacement measuring instrument having a configuration for optically detecting the displacement of a spindle that comes into contact with an object to be measured.

  The displacement measuring device is also called a length measuring device or a dial gauge, and is used when a spindle is brought into contact with an object to be measured and a displacement amount with respect to a reference is measured. In recent years, a displacement measuring device for detecting the amount of displacement of a spindle by digital conversion by an optical measuring method using an optical element has also been manufactured. As a prior art of the displacement measuring device, for example, there is a displacement measuring device of Patent Document 1 previously disclosed by the present applicant.

  In the displacement measuring device of Patent Document 1, a scale member (30) is disposed between a light projecting element (40) and a light receiving element (41), and a spindle (20) to which the scale member (30) is fixed. The amount of displacement of the measurement object is detected by optically measuring the displacement of. The light beam from the light projecting element (40) that has passed through the scale member (30) enters the light receiving element (41) and is converted into an electrical signal. The intensity of the electrical signal generated by the light receiving element (40) needs to be adjusted according to the specification of the detection circuit to which the displacement measuring device is connected. When output from (40), the detection accuracy is the highest.

  Here, it is known that the gap between the scale member (30) and the light receiving element (41) has a great influence on the intensity of the electric signal generated in the light receiving element (40). For this reason, in the displacement measuring instrument of Patent Document 1, the error is minimized by paying close attention to the processing accuracy and assembly accuracy of the component parts, and the worker manually reduces the gap during assembly. I was adjusting.

However, as a result of processing and assembling each component with high accuracy, the conventional displacement measuring instrument has a problem that the manufacturing cost is high and the productivity is poor. In addition, skill is required for manual gap adjustment of workers, and there is a problem that work efficiency is poor.
Patent Document 2 discloses an interval adjustment mechanism (5) for simplifying a gap adjustment between a scale (1) corresponding to the scale member and a detection head (2) corresponding to the light receiving element (41). Is disclosed. However, since this interval adjusting mechanism (5) is configured to abut against the scale (1), the scale (1) may be damaged, and the interval adjusting mechanism (5) includes the scale (1). There is no function to relatively move and adjust the detection head (2), and Patent Document 2 does not disclose any such movement adjusting mechanism.
JP 2006-349473 A JP-A-2-112724

  The present invention has been made in view of such circumstances, and it is possible to easily adjust a gap between a scale member and a light receiving element, and to provide a displacement measuring instrument that can efficiently perform an assembly operation. Objective.

In order to achieve the above object, the present invention provides a main body case, a spindle incorporated in the main body case and movable in the axial direction, a scale drawn on a transparent plate, and a scale attached to the spindle. In a displacement measuring instrument including a member, and a light projecting element and a light receiving element disposed at opposing positions across the scale member in the main body case,
A gap adjusting mechanism is provided that finely adjusts the distance between the scale member and the light receiving element by moving the light receiving element toward or away from the scale member.

  According to such a configuration, the gap adjustment mechanism can very finely adjust the distance between the scale member and the light receiving element, and the working efficiency during assembly is dramatically improved.

Here, the scale member has a structure in which a scale (scale) is engraved on a transparent plate,
Furthermore, it is preferable that the light receiving element is disposed on the back side of the scale member inside the main body case and is visible through the transparent plate of the scale member.

  In general, in order to improve the detection accuracy of the light receiving element, it is necessary not only to arrange the scale parallel to the light receiving surface of the light receiving element but also to match the direction of the light receiving surface on the xy plane with the direction of the scale. Become. As described above, if the light receiving element is arranged on the back side of the scale member, when the scale member is attached to the spindle, the lattice plane of the light receiving element can be visually recognized through the transparent plate, and on the xy plane. It becomes possible to easily match the direction of the light receiving surface with the direction of the scale.

  In addition, if the gap adjusting mechanism is configured to include an operation unit for adjusting the movement of the light receiving element exposed to the outside of the main body case, the gap between the scale member and the light receiving element is required even after assembly. Adjustment is possible, and high measurement accuracy can be maintained over a long period of time.

  Further, the light projecting element and the light receiving element are held by the holder, and the operation unit is configured by an adjustment screw that is inserted from the outside of the main body case and screwed into the holder, and the holder is moved by rotating the adjustment screw. With this configuration, assembly is facilitated with a simple configuration, and the interval between the scale member and the light receiving element can be finely adjusted only by rotating the adjusting screw.

  As described above, according to the displacement measuring instrument of the present invention, since the gap between the scale member and the light receiving element can be easily adjusted, the gap management necessary for the assembly work becomes unnecessary, and the assembly efficiency is improved. Can be planned.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 7 are diagrams showing a configuration of a displacement measuring instrument according to an embodiment of the present invention. FIG. 1 is a perspective view showing the overall configuration of the displacement measuring instrument according to the present embodiment, and FIG. 2 is an exploded perspective view showing the overall configuration of the displacement measuring instrument. In the following description, the vertical direction is specified by the arrangement shown in FIG.

  As shown in FIGS. 1 and 2, the displacement measuring instrument of the present embodiment includes a main body case 10, a rod-shaped spindle 20, a scale member 30, a light projecting element 40 and a light receiving element 41, and a sensor position adjusting member 47. And a bias adjusting mechanism 50 including an urging spring 54 and an adjusting screw 53. Details of the gap adjusting mechanism 50, which is a feature of the present invention, will be described later.

  The main body case 10 includes a base member 11 having a U-shaped cross section, partition members 12 and 13 attached to both end openings of the base member 11, and a lid body 14 attached to the front opening of the base member 11. Is included. A bearing member 16 is attached to each partition member 12, 13 via a stopper rubber 15. A guide pin insertion hole 17 and a fixing screw insertion hole 18 are formed in one side surface of the base member 11, and an adjustment screw insertion hole (not shown) is formed in the lower surface of the base member 11. ing. A guide pin 51, a fixing screw 52, and an adjusting screw 53, which will be described later, are inserted through these insertion holes.

FIG. 3 is a perspective view showing an assembled state of the spindle and the scale member of the displacement measuring instrument according to the present embodiment.
The spindle 20 is supported by each of the bearing members 16 so as to be movable in the axial direction, and is incorporated into the main body case 10. As shown in FIGS. 1 and 2, a measuring element 21 that comes into contact with an object to be measured is attached to the tip of the spindle 20. As shown in FIG. 3, the spindle 20 is formed with a flat portion 22 (see FIG. 2) parallel to the central axis by cutting out the intermediate portion. A positioning hole that penetrates the spindle 20 is formed in the flat portion 22, and a positioning pin 23 is fitted and fixed to the positioning hole. The scale member 30 is screwed to the flat portion 22 by a screw member 36 so as to engage with the positioning pin 23.

  The scale member 30 has a configuration in which a glass scale (transparent plate) 32 is incorporated in a scale holder 31 formed of a metal plate. On the glass scale 32, light shielding films 33 serving as scales (scales) are formed at regular intervals, and slit-like light transmission portions 34 are formed at regular intervals between the light shielding films 33. Further, a notch 35 (see FIG. 2) is formed at one end edge of the scale holder 31, and this notch 35 is configured to engage with the positioning pin 23 described above.

FIG. 4 is a perspective view showing an assembled state of the light projecting element and the light receiving element to the sensor holder.
The light projecting element 40 and the light receiving element 41 are mounted on a sensor holder 44 having a substantially U-shaped cross section. At this time, the light projecting element 40 and the light receiving element 41 are arranged to face each other with a certain gap. The scale member 30 mounted on the spindle 20 can be freely moved in the moving direction of the spindle 20 between the light projecting element 40 and the light receiving element 41 arranged opposite to each other. The light projecting element 40 and the light receiving element 41 are mounted on a flexible substrate (FPC) 42 and connected to a detection circuit (not shown) via an external conductor 43 (see FIG. 2).

  As shown in FIG. 4, the sensor holder 44 includes a light receiving side plate member 45 to which the light receiving element 41 is attached, a light emitting side plate member 46 to which the light projecting element 40 is attached, a light receiving side plate member 45 and a light emitting side plate member 46. And a sensor position adjusting member 47 to be connected. The sensor holder 44 is formed in a substantially U shape by assembling these members.

  The displacement measuring instrument of the present embodiment includes a gap adjusting mechanism 50 configured as shown in FIGS. The gap adjusting mechanism 50 is a mechanism for finely adjusting the gap (gap) between the light receiving element 41 and the scale member 30. The gap adjusting mechanism 50 is formed in a U-shape on both sides of the position where the adjusting screw 53 is screwed into a lower surface screw hole (not shown) on the lower surface of the sensor position adjusting member 47 and further the adjusting screw 53 is screwed. The biasing spring 54 is provided. The adjustment screw 53 is inserted from the main body case 10 and screwed into the lower surface screw hole of the sensor position adjustment member 47 in the assembled state of the displacement measuring instrument. On the other hand, the biasing spring 54 is disposed in the notch 47a of the sensor position adjusting member 47 in the assembled state of the displacement measuring device.

  The back surface of the sensor position adjusting member 47 has two elongated holes 47b on the top and bottom and two side screw holes 47c on the left and right. In the sensor position adjusting member 47, when assembling the displacement measuring instrument, the guide pin 51 is inserted into the elongated hole 47b, and the fixing screw 52 is screwed into the side screw hole 47c.

  The fine adjustment by the gap adjusting mechanism 50 is performed by rotating the adjustment screw 53 inserted in the lower surface of the main body case 10 and sliding the sensor holder 44 up and down. Thereby, the light receiving element 41 is moved in the direction of approaching or separating, and the gap with the scale member 30 is finely adjusted. At this time, since the urging spring 54 at the lower part of the position adjusting member 47 urges the sensor holder 44 in the upward direction, fine adjustment is possible without rattling. This fine adjustment is performed while confirming the display of the measuring apparatus connected via the external lead wire 43.

  The fixing screw 52 is loosened during the gap adjustment, and is tightened strongly after the adjustment work is completed. Thereby, the sensor holder 44 is fixed to the main body case 10. In the state where the fixing screw 52 is loosened, the sensor position adjusting member 47 is pulled toward the outside of the base member 11 in the main body case 10 by the spring force of the washer 55. Accordingly, even when the gap is being adjusted, the sensor holder 44 can be positioned in close contact with the inner peripheral surface of the main body case 10 by the washer 55, and the position of the scale member 30 and the light receiving element 41 can be adjusted. Only the gap can be adjusted without changing the relationship.

  As described above, if the gap measuring mechanism 50 described above is provided in the displacement measuring device, the members shown in FIG. 2 are assembled to form the displacement measuring device, and then, if necessary, between the scale member 30 and the light receiving element 41. Can be easily adjusted, and the light receiving accuracy of the sensor can be finely adjusted. In addition, according to the present invention, since the gap can be adjusted after assembling the measuring instrument, in order to improve the measurement accuracy as in the conventional configuration, the processing accuracy of the contact surface with which each component comes in contact is extremely reduced. There is no need to increase it. Thereby, the manufacturing cost of the displacement measuring device can be kept low. Therefore, the gap management necessary for the assembly work becomes unnecessary, and the assembly efficiency can be improved.

  If the displacement measuring instrument is measured over a long period of time and it is found that the measurement result is out of order, the scale adjusting member 30 and the light receiving element 41 can be easily obtained by the gap adjusting mechanism 50 without having to disassemble the displacement measuring instrument. The gap between can be adjusted. Thereby, it becomes possible to always maintain high measurement accuracy stably.

Next, the detailed structure of the displacement measuring instrument according to the present embodiment and the assembly procedure of each component will be described with reference mainly to FIG.
To assemble the displacement measuring instrument, first, the light receiving side plate member 45 to which the light receiving element 41 is attached is screwed to the sensor position adjusting member 47, and the sensor holder 44 is mounted on the main body case 10 in this state. At this time, an urging spring 54 is incorporated in the notch 47 a of the sensor position adjusting member 47, and the adjusting screw 53 is inserted into the adjusting screw insertion hole from below the main body case 10, so that the lower surface screw of the sensor position adjusting member 47 The gap adjusting mechanism 50 is formed by screwing into the hole.

  Next, from the side surface of the base member 11 of the main body case 10, the two guide pins 51 are inserted into the guide pin insertion holes 17 and are inserted into the long holes 47 b of the sensor position adjustment member 47. Similarly, from the side surface of the base member 11, two fixing screws 52 are inserted into the fixing screw insertion hole 18 via a washer 55 having elasticity, and loosely screwed into the side screw hole 47 c of the sensor position adjusting member 47. The sensor holder 44 is temporarily fixed to the main body case 10.

Here, in this embodiment, the hole diameter of the guide pin insertion hole 17 is set to a dimension that allows the guide pin 51 to fit without rattling, and the long hole 47b is formed to have a long hole diameter in the vertical direction. For this reason, in a state where the guide pin 51 is inserted into the guide pin insertion hole 17 and the long hole 47b, the guide pin 51 is firmly fitted into the guide pin insertion hole 17, and a gap is vertically formed at the insertion portion of the long hole 47b. It will have a state.
On the other hand, the hole diameter of the fixing screw insertion hole 18 is sufficiently larger than the outer diameter of the thread portion of the fixing screw 52, and the side screw hole 47 c is formed to have a hole diameter that can be screwed with the fixing screw 52. For this reason, in the state where the fixing screw 52 is inserted into the fixing screw insertion hole 18 and the side screw hole 47c, the fixing screw 52 leaves a gap around the fixing screw insertion hole 18 and is screwed into the side screw hole 47c. It becomes.
Therefore, the sensor holder 44 is slidable up and down at the stage where the guide pin 51 is inserted into the sensor position adjusting member 47 and the fixing screw 52 is loosely screwed and temporarily fixed.

  Next, the positioning pin 23 is attached to the spindle 20, and the spindle 20 is assembled into the main body case 10. Here, a spring arrangement portion 19 is formed on the base member 11 of the main body case 10 adjacent to the mounting location of the sensor holder 44. A partition wall 19a is formed on both sides of the spring arrangement portion 19, and an urging spring 60 is disposed at a portion sandwiched between the partition walls 19a and one end thereof is locked. Further, the tip of the positioning pin 23 is inserted into the other end of the biasing spring 60. As a result, the spindle 20 can slide in the axial direction.

  Further, the spindle 20 is supported by the bearing members 16 provided on the partition members 12 and 13 of the main body case 10 so as to be movable in the axial direction. In this state, the partition members 12 and 13 are attached to the base member 11 and the spindle 20 is assembled into the main body case 10.

Next, the scale member 30 is attached to the spindle 20 incorporated in the main body case 10. The scale member 30 is disposed on the flat portion 22 of the spindle 20 with the notch 35 engaged with the positioning pin 23, and is attached to the spindle 20 by a screw member 36 (see FIG. 3).
Since the scale member 30 is only fastened by the single screw member 36, the planar position of the scale member 30 can be easily finely adjusted simply by loosening the screw member 36 even after being incorporated into the main body case 10. It is possible.

FIG. 7 is a schematic diagram showing the relationship between the scale member and the light receiving element of the displacement measuring instrument according to this embodiment.
Here, as shown in FIG. 7A, the light receiving element 41 of the displacement measuring device is formed by an array of lattice planes 41a having a plurality of square-shaped light receiving surfaces. Then, when assembling the displacement measuring device, it is necessary to adjust the direction of the lattice surface 41a on the xy plane and the direction of the scale (scale) formed by the light shielding film 33 of the scale member 30.
As shown in FIG. 7B, the light receiving accuracy of the light receiving element 41 is reduced if the scale (scale) formed by the grating surface 41a and the light shielding film 33 is shifted from a predetermined position and rotated. In addition to this, it causes a decrease in measurement accuracy.

  The displacement measuring instrument of the present embodiment is in a state where the sensor holder 44 is installed in the main body case 10, and the light receiving element 41 is disposed below the scale member 30. Therefore, it is possible to visually recognize the lattice surface 41 a of the light receiving element 41 through the glass scale 32 of the scale member 30. By enabling the visual recognition in this way, the worker can easily and accurately adjust the scale (scale) of the scale member 30 and the lattice surface 41a when the scale member 30 is incorporated into the spindle 20. it can.

  After the scale member 30 is mounted on the spindle 20 and the positional relationship between the light receiving element 41 and the scale member 30 is adjusted, the light projecting side plate member 46 having the light projecting element 40 mounted on the sensor position adjusting member 47 is mounted. . Thus, the sensor holder is completed. At this time, the sensor holder 44 is in a state in which a certain gap is formed between the light projecting element 40 and the light receiving element 41, and the scale member 30 is interposed between the gaps.

  After assembling as described above, the gap between the light receiving element 41 and the scale member 30 is finely adjusted by the gap adjusting mechanism 50. This adjustment work is as described above.

  Finally, the lid 14 is attached to the front opening of the base member 11 to complete the assembly of the displacement measuring instrument. By assembling the displacement measuring device in this way, the work efficiency of the assembly work can be improved and the manufacturing cost can be reduced.

  When fine adjustment of the amount of light received by the light receiving element 41 is desired after completion of the assembly, as described above, the sensor holder 44 is temporarily fixed by loosening the fixing screw 52 and then turning the adjustment screw 53 to turn the sensor holder. 44 is slid. Accordingly, the gap between the scale member 30 and the light receiving element 41 can be easily adjusted without disassembling the displacement measuring instrument, and the light receiving accuracy of the sensor can be finely adjusted.

  In addition, this invention is not limited to embodiment mentioned above, A various deformation | transformation implementation or application implementation is possible as needed. For example, as for the positional relationship between the light projecting element 40 and the light receiving element 41 in the displacement measuring device, the light receiving element 41 can be disposed on the upper side and the light projecting element 40 can be disposed on the lower side as in the prior art.

  In the above description, an example in which the position of the scale is adjusted by the scale (scale) of the scale member 39 and the lattice surface 41a has been described. Instead, the scale (scale) and the surface of the light receiving element 41 are provided separately. The adjustment may be made according to the mark or the mark provided on the surface of the light receiving element 41 and the mark provided on the surface of the scale.

  Furthermore, in the present embodiment, an example in which the biasing springs 54 disposed on both sides of the position where the adjustment screw 53 is screwed in the gap adjusting mechanism 50 is U-shaped has been shown. As long as an urging force is applied to one side, the same effect as in the present invention can be obtained even if the coil shape or the V shape is used.

It is a perspective view which shows the whole structure of the displacement measuring device which concerns on this embodiment. It is a disassembled perspective view which shows the whole structure of the displacement measuring device which concerns on this embodiment. It is the perspective view which showed the assembly state of the spindle and scale member of the displacement measuring device which concerns on this embodiment. It is a perspective view which shows the assembly state of the sensor holder of the displacement measuring device which concerns on this embodiment, a light projection element, and a light receiving element. It is the perspective view which looked at the assembly state of the sensor holder of the displacement measuring device which concerns on this embodiment, a light projection element, and a light receiving element from another direction. It is front sectional drawing which shows the structure of the displacement measuring device which concerns on this embodiment. It is a schematic diagram which shows the relationship between the scale member and light receiving element of the displacement measuring device which concerns on this embodiment.

Explanation of symbols

10: body case, 11: base member, 12, 13: partition member, 14: lid, 15: stopper rubber, 16: bearing member, 17: guide pin insertion hole, 18: fixing screw insertion hole, 19: spring arrangement Part, 19a: partition wall,
20: Spindle, 21: Measuring element, 22: Flat part, 23: Positioning pin,
30: Scale member, 31: Scale holder, 32: Glass scale, 33: Light shielding film, 34: Light transmission part, 35: Notch part, 36: Screw member,
40: light projecting element, 41: light receiving element, 42: flexible substrate, 43: external conductor, 44: sensor holder, 45: light receiving side plate member, 46: light emitting side plate member, 47: sensor position adjusting member, 47a: notch 47b: long hole, 47c: side screw hole,
50: Gap adjustment mechanism, 51: Guide pin, 52: Fixing screw, 53: Adjustment screw, 54: Biasing spring, 55: Washer

Claims (4)

A body case,
A spindle built into the main body case and movable in the axial direction;
A scale member drawn on a transparent plate, and a scale member mounted on the spindle;
In the main body case, a displacement measuring instrument including a light projecting element and a light receiving element disposed at opposing positions across the scale member,
A displacement measuring instrument comprising a gap adjusting mechanism that finely adjusts an interval between the scale member and the light receiving element by moving the light receiving element toward or away from the scale member. The scale member has a configuration in which a scale is engraved on the transparent plate,
The displacement measuring device according to claim 1, wherein the light receiving element is disposed on the back side of the scale member inside the main body case and is visible through a transparent plate of the scale member. The displacement measuring device according to claim 1, wherein the gap adjusting mechanism includes an operation unit for adjusting the movement of the light receiving element exposed to the outside of the main body case. The light projecting element and the light receiving element are held by a holder,
The displacement according to claim 3, wherein the operation unit is an adjustment screw that is inserted from the outside of the main body case and is screwed into the holder, and the holder is moved by a rotation operation of the adjustment screw. Measuring instrument.

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