JPS5916642B2 - displacement measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a displacement measuring device that reads and measures relative movement between a translucent main scale and an index scale facing the main scale using a light emitting element and a light receiving element. .

Conventional measuring instruments of this type have a main scale made of glass or the like arranged along the longitudinal direction in a hollow elongated case formed by cold drawing, and an index scale arranged opposite to this main scale. The scale is attached via a slider to the arm of the detection mechanism inserted through an opening formed along the longitudinal direction of the case, and a light emitting element and a light receiving element are provided on the slider to control relative movement between the detection mechanism and the case. The light and darkness formed between both scales is detected and measured by a light receiving element.

The slider is movably provided on the arm of the detection mechanism and is biased toward the sea side by a spring, so that the slider provided on the slider comes into contact with the scale surface of the main scale and the side surface orthogonal to the scale surface. It is becoming more and more accessible. This allows the slider to move while being guided by the scale surface and side surface of the main scale, with the scale portion of the main scale and the scale portion of the index scale facing each other.
FIG. 1 shows a slider biasing means in a conventional measuring instrument of this type.

In the figure, a through hole 5A is provided at each end of the arm portion 5 which is divided into two legs, and both ends of a spring 12 made of a single linear spring are inserted into the through hole 5A. A bent portion at one end is fixed to a screw 5B. The slider 13 has an L-shaped slider mounting member 13A placed across the upper side of the main scale 10, and a slider mounting member 13A (7) located on the short side of the L-shape, that is, on the back side of the page (not shown). It is composed of a light emitting element mounting member (not shown) fixed to the side thereof, a slider mounting member 13A (7), and a front T-shaped light receiving element mounting member 13C fixed to the long side of the L shape. . This light-receiving element mounting member 13C has a light-receiving element 16 and a through hole 1 at the lower end of the T-shape.
3D, and the spring 12 is inserted halfway into the through hole 13D and fixed with a screw 13E. At this time, the spring 12 is in a straight line connecting the through holes 5A in the free down state, and in the assembled down state with a spring force applied, the spring 12 is in the first position.
As shown in the figure, it is said to have a curved shape towards Hijikata.
As a result, the slider 13 is urged toward the main scale 10 side, and the resin slider 17 attached to the inner surface of the slider attachment member 13A of the slider 13 is moved toward the scale surface of the main scale 10 and this It is arranged to abut on a side surface perpendicular to the scale surface. However, when the arm portion 5 and the slider 13 are connected using the spring 12 made of such a single wire spring, there are the following disadvantages.

That is, since the spring 12 is thin, for example, with a diameter of about 0.41L1L, it is structurally unstable to fix the spring 12 to the arm part 5} and the slider 13, and when the screws 5B and 13E are used, each screw 5B, As the tightening force of 13E decreases, it becomes easier to loosen, and on the other hand, even if you try to fix it with adhesive, you cannot expect strong adhesive force because the adhesive area is small.
In any case, the spring force of the spring 12 tends to change during use. Also, 0.41W! The diameter of the hole for inserting the line is also small, and if the hole in the arm portion 5 is made at an angle, the spring 12 will be set in a bent position from the beginning, causing variations in the spring force. Furthermore, since the wire diameter of the spring 12 is small, the spring 12 is deformed when the slider 13 and the main scale 10 come into sliding contact, and the pressure force changes, causing the slider 13 to move against the main scale 10. One side may lift up, and if the contact with the main scale 10 becomes uncertain, the vertical striped scale portion of the main scale 10 and the vertical striped scale portion of the index scale (not shown) attached to the slider 13 may become unstable. The scale part of the stripes is no longer parallel, causing miscounts. This floating phenomenon of the slider 13 is caused by the spring 12 made of a line spring.
This may also be due to the fact that it is weak against force in the torsional direction. SUMMARY OF THE INVENTION An object of the present invention is to provide a displacement measuring instrument in which the slider and the main scale are brought into contact with uniform pressing force even when the slider and the main scale move relative to each other, and there is no miscount.

In particular, the present invention includes a line spring that urges a slider in a direction to bring a main scale and an index scale closer together, and a line fall spring that is fitted over the line fall spring and that rotates the slider approximately about the axis of the line fall spring. The above object is achieved by providing a spring structure consisting of a coil spring that allows the wire spring and a coil spring to act independently of the wire spring, and installing the coil spring across the slider and the arm. This is what I am trying to do.

An embodiment of the present invention will be described below with reference to FIG. 2 and FIG. 3.

A case 1 formed by cold drawing has a substantially rectangular hollow cross section, is elongated, and has an opening 2 along one longitudinal side.

A detection mechanism 3 is brought into contact with the opening side end surface of the case 1 via a sliding member 4, and is movable along the longitudinal direction of the case 1.

The arm portion 5 formed on the lower surface of this detection mechanism 3 is connected to the opening 2.
It is extended into case 1. A pair of magnets 6 are provided along the longitudinal direction of the case 1 on the outer surface of the case 1 near the opening 2, and a closing member 7 made of a thin iron plate is attached to the magnet 6 so as to cover the opening 2. This prevents dust and the like from entering into the case 1 through the opening 2. At this time, the closing member 7 in the portion of the detection mechanism 3 into which the arm portion 5 is inserted is a side chevron-shaped groove 8 that is provided in the detection mechanism 3 and has both ends opened on the lower surface of the detection mechanism 3.
The arm portion 5 in the prone position, which is inserted into the case 1 and straddled by the groove 8, can be inserted into the case 1. Into the groove 9 provided in the longitudinal direction in the case 1, the lower edge of the main scale 10, which is made of glass or the like and has vertical striped scales formed on one side, is inserted and fixed with an adhesive 11 or the like. has been done.

The arm portion 5 of the detection mechanism 3 extends to the vicinity of the main scale 10, and a slider 13 is movably attached to the tip of the arm portion 5 via a spring structure 12. As shown in FIG. 3, this spring structure 12 includes a tightly wound coil spring 12A serving as a support member, and is inserted through the coil spring 12A so as to be freely movable, and both ends are bent to prevent it from coming off. The spring 12B is made up of a single wire spring 12B. In addition, this spring structure 12 is in a substantially straight line in the free lying state, and in the assembled lying state with a spring force applied, it is curved upward with a gentle curvature as shown in FIG. ing. As a result, the slider 13 is urged in a predetermined direction, that is, in the direction of the main scale 10. Further, the spring structure body 12 and the arm portion 5 are attached by inserting both ends of the spring structure body 12 into the respective through holes 5A provided at the bent tip of the arm portion 5, and One end is attached to screw 5B.
It is fixed and carried out. Furthermore, the spring structure 12 and the slider 13 are attached to a front T-shaped light receiving element which is fixed to a slider mounting member 13A having an L-shaped side surface and constitutes the slider 13 together with a thick light emitting element mounting member 13B. The spring structure 12 is inserted halfway into a through hole 13D provided in the mounting member 13C, and is fixed with a screw 13E. An index scale 14 having vertically striped scales similar to the main scale 10 is fixed to the surface of the slider mounting member 13A of the slider 13 facing the main scale 10.

A light-emitting element 15 and a light-receiving element 16 are arranged in a down position sandwiching the index scale 14 and main scale 10. At this time, the light emitting element 15 is attached to the light emitting element attachment member 13B fixed to the short side of the L-shape of the slider attachment member 13A (7), and the light receiving element 16 is attached to the slider attachment member 13A (7).
3A (7) Light receiving element mounting member 1 fixed to the long side of the L shape
Two of each are fixed to 3C. The slider mounting member 13
A(7) A plurality of sliders 17 made of resin with a low coefficient of friction are fixed to the inner surface of the L-shape, that is, the scale surface of the main scale 10 and the surface facing the side surface perpendicular to this scale surface. The slider 17 is brought into contact with the scale surface of the main scale 10 and the side surface perpendicular to the scale surface by the biasing force of the spring structure 12.

In such a configuration, when either the case 1 or the detection mechanism 3 is attached to the object to be measured and the object to be measured is moved with the other force fixed, the scale of the main scale scale 10 and the index scale scale 14 will change. A bright and dark striped pattern is generated between the scales, and this striped pattern is read by the light emitting element 15 and the light receiving element 16 to read and measure the amount of movement of the object to be measured.

At this time, the slider 13 is not directly connected to the spring structure 12.
Since the slider 13 is supported by the coil spring 12A, the torsional force accompanying the movement of the slider 13 is absorbed by the coil spring 12A and does not deform the line spring 12B. 13 sliders 17
and the main scale 10 can slide while being in contact with each other. As described above, according to this embodiment, the arm portion 5 of the detection mechanism 3 and the slider 13 are connected to the closely wound coil spring 12A as a supporting member and the wire spring inserted and supported within the coil spring 12A. 12B, the main scale 10 of the slider 13
Main scale 1
Counting errors due to the inclination of the scale between 0 and the index scale 14 can be prevented.

Further, in the spring structure 12, the line spring 12B is the coil spring 1.
Since it is loosely inserted into the wire lowering spring 12A, no unreasonable force such as in the screw direction is applied to the wire lowering spring 12B.
B is not deformed, therefore, the line spring 12B and the spring structure 12 are prevented from becoming sagging, and the lifespan can be extended. Furthermore, a through hole 5A is formed to attach the spring structure 12.
, 13D has a larger diameter, so the conventional 0.4m7! The processing properties are better than those of about L, and the fixing of the spring structure 12 with the screws 5B, 13E can be stabilized, and it can also be securely fixed with an adhesive without using the screws 5B, 13E. In addition, in implementation, the tightly wound coil spring 12A as a support member may be another member such as a flexible synthetic resin tube, but the coil spring 12A
If , the deforming force applied to the line spring 12B is small,
Another advantage is that it is easy to fix to the arm portion 5 and slider 13.

Moreover, the slider 17 may be a ball bearing. As described above, according to the present invention, the pressure force of the slider against the main scale is stabilized, and there is an effect that it is possible to provide a displacement measuring instrument with less measurement errors due to miscounts.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the main parts of a conventional displacement measuring device, Fig. 2 is a cross-sectional view showing an embodiment of the displacement measuring device according to the present invention, and Fig. 3 is a cross-sectional view taken along the - line in Fig. 2. It is a diagram. 1...Case, 2...Opening, 3...
...Detection mechanism, 5...Arm part, 10...
・Main scale, 12... Pan structure, 12
A...Tightly wound coil spring, 12B...
... Line spring, 13 ... Slider 14.
...Index scale, 15 ... Light emitting element, 16 ... Light receiving element.

Claims (1)

[Claims] 1. Insert the arm of the detection mechanism through the longitudinal opening of the case containing the main scale, attach the slider to this arm with the slider biased toward the main scale, and connect the index scale and A displacement measuring device in which a light emitting element and a light receiving element are mounted on the slider so as to face each other with the main scale in between, and these elements detect the amount of relative movement between the detection mechanism and the case. a linear spring that biases the scale in a direction to approach the scale; and a linear spring that is fitted over the linear spring to allow rotation of the slider approximately about the axis of the linear spring, and that is independent of the linear spring. 1. A displacement measuring device, comprising: a spring structure comprising a coil spring acting as a spring; and the coil spring is attached by spanning a slider and an arm.