JPH059605Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a microscale that detects the amount of movement, position, dimension, etc. as a digital signal.

(Prior Art) Recently, a microscale has been developed that electrically detects the displacement of a rod and displays it digitally instead of directly reading the scale. In this type of microscale, an operating member is screwed to one end of the scale body, and a rod is inserted through the other end. The operating member and the rod are integrally connected, and when the operating member is rotated, the rod moves forward or backward.

However, in the above configuration, since the operating member is displaced with respect to the scale body during rotation operation,
The length of the microscale, excluding rods, changes. Therefore, since the installation space must be determined based on the maximum length of the microscale, a relatively large installation space is required. In addition, microscales are usually supported by a stem or the like at a predetermined part of the scale body, but as the length of the microscale changes as mentioned above, its center of gravity is displaced relative to the supporting position, resulting in minute measurement error occurs.

In order to deal with this, the applicant made further improvements and published Utility Application No. 58-131184 and U.S. Pat.
Developed the device No. 33139. Since this device has a conversion mechanism that converts the rotation of the operating member into the linear movement of the rod, the length of the microscale excluding the rod can be kept constant when the rod advances or retreats. Furthermore, the installation space of the microscale is small and the center of gravity of the microscale does not displace with respect to its supporting position, so measurement errors caused by this displacement can be eliminated.

(Problem that the invention is trying to solve) However, with the above configuration, when the limit of the allowable range of the forward and backward movement of the rod is reached and the rod becomes unable to move, if the operating member is further rotated, the Excessive stress is applied to the conversion mechanism, causing slight deformation, and even if the operating member is rotated in the opposite direction to return the rod to its original position, there is a risk that the above deformation may cause a slight measurement error.

(Means for solving the problem) This invention was made to solve the above problem, and its gist is a scale body and a scale body supported by the scale body so as to be movable in the direction of its own axis. a rod member, an operating member rotatably supported by the scale body, a conversion mechanism that converts rotation of the operating member into linear movement of the rod member, and a conversion mechanism arranged along the axial direction of the rod member. , comprising a main scale fixed to the scale body, and a vernier scale disposed opposite to the main scale and connected to the rod member so as to move linearly together with the rod member, and rotating the operating member. In a microscale that measures the movement distance of the rod member by scanning the main scale with a vernier scale, the scale body engages with the operating member to prevent rotation thereof in one direction. An engaging member is provided that is movable between a first position and a second position that is separated from the operating member and allows rotation in one direction, and the engaging member and the rod member are connected to each other. During this period, the engaging member is moved from the second position to the first position by the linear movement of the rod member due to the rotation of the operating member in one direction, and the operating member is rotated in the other direction. The micro-scale device is characterized in that it is provided with a moving mechanism that moves the engaging member from the first position to the second position by the linear movement of the rod member.

(Example) Hereinafter, an example of this invention will be described based on the drawings from FIG. 1 to FIG. 5.

FIG. 1 is a longitudinal sectional view showing the microscale of this invention. Reference numeral 1 in the figure is a scale body, and the scale body 1 includes a cylindrical member 10 with a bottom, a disc-shaped support member 11 fixed to one end of the cylindrical member 10, and a support member 11 fixed to one end of the cylindrical member 10. The guide member 12 is fixed to the inside of the other end.

At the center of the support member 11, a long rotary shaft 2 is rotatably supported with its axis aligned with the axis of the scale body 1. A bottomed cylindrical operating member 3 is fixed to the outer end of the rotating shaft 2 with a bolt 31 or the like via a spacer 30 with its axis aligned with the axis of the rotating shaft 2 . This operating member 3 is provided so as to cover a part of the cylindrical member 10, and is configured to be rotated by a knob 32. Further, a rubber band 33 is attached to the outer periphery of the operating member 3.

A bearing portion 13 is formed in the guide member 12, and a hollow cylindrical rod 4 is supported by the bearing portion 13 so as to be movable forward and backward with its axis aligned with the axis of the scale body 1. .

A conversion mechanism 5 is provided within the scale body 1. This conversion mechanism 5 is for converting the rotation of the operating member 3 into a linear movement of the rod 4, and is connected to the rotation shaft 2 and the rotation shaft 2.
The movable member 7 is screwed into the male threaded portion 6 of the rotary shaft 2, and a pair of guide rods 8, 8 are used to prevent the movable member 7 from rotating together with the rotation of the rotary shaft 2.

The moving member 7 is a hollow cylindrical member,
The inner peripheral wall has a female threaded hole 70 that screws into the male threaded part 6.
is formed. Further, the proximal end portion of the rod 4 is integrally fixed to the guide member 12 side of the movable member 7, and the rod 4 and the movable member 7 constitute a rod member 40. The rod 4 is a hollow member having an inner diameter equal to or larger than the outer diameter of the male threaded portion 6 of the rotating shaft 2, and can move along the outer circumference of the rotating shaft 2 together with the moving member 7. Furthermore, holding portions 71 and 72 are formed on the outer peripheral portion of the moving member 7 and extend in the radial direction.
The pair of guide rods 8, 8 are arranged parallel to the axis of the scale body 1, one end of which is fixed to the support member 11, and the other end of which is fixed to the guide member 12.
is fixed. The middle part of the guide rods 8, 8 is
It is movably inserted into holes 73 and 74 formed in each of the holding parts 71 and 72 of the moving member 7. This prevents the moving member 7 from rotating together with the rotating shaft 2.

The moving member 7 is provided with a detection device 9, as shown in FIG. This detection device 9 includes a mounting member 90 having a U-shaped cross section, a main scale 91, and a main scale 91.
A vernier scale 92 facing the , and a pair of light emitters 93
and a pair of light receiving elements 94, 94 facing a pair of light emitters 93, 93.

The mounting member 90 is fixed to the movable member 7, and the vernier 92 is attached to the inner surface thereof.

One end of the main length 91 is fixed to the guide member 12, and the other end is inserted into the inside of the mounting member 90. Further, the main scale 91 is installed parallel to the rod 4 and the vernier scale 92. The main scale 91 and the vernier scale 92 are
For example, it is made of a transparent plate such as glass, and the main length 91 is longer than the vernier length 92. And the fifth
As shown in the figure, on the main scale 91, a large number of stripes 95 in a direction perpendicular to the longitudinal direction are displayed at a predetermined pitch in the longitudinal direction. The stripes 95 have a small width (for example, several microns), and this width is equal to the spacing between the stripes 95. The vernier measure 92 also includes a main measure 91.
A large number of stripes 96 parallel to the stripes 95 and having the same width are displayed at the same pitch. Left half of vernier measure 92 9
The stripes 96 in 2a and the stripes 96 in the right half 92b are 1/
They are arranged 4 pitches (90 degrees) apart.

A pair of light emitters (for example, LEDs) 93, 93 are installed on one side of the mounting member 90. Also, a pair of light receiving elements (for example, phototransistors) 94,
94 is a pair of light emitters 9 on the other side of the mounting member 90.
It is installed facing 3,93. Each light emitter 9
3 and each light receiving element 94 is the main scale 91 mentioned above.
and a vernier measure 92 are arranged. 1 set of light emitters 93
The light receiving element 94 is arranged on the left half 92a of the vernier 92, and the other sets are arranged on the right half 92b of the vernier 92.

As shown in FIGS. 3 and 4, the operating member 3
A protrusion 34 is provided on the bottom surface. A hole 11a and a hole 12a are formed in each portion of the support member 11 and the guide member 12 located on the opposite side of the detection device 9 with respect to the rotating shaft 2. A long sub-rod (engaging member) 14 is supported between the holes 11a and 12a so as to be movable forward and backward. This subrod 14 is
It is parallel to the rotating shaft 2. This subrod 14 is adapted to be moved in the axial direction by a moving mechanism 50. The moving mechanism 50 is
It is structured as follows.

That is, a collar 14 is fixed to a predetermined position on the support member 11 side of the sub-rod 14, and between the collar 14a and the inner surface of the support member 11, the sub-rod 14 is moved from the support member 11 side to the guide member 12 side. A spring 15 is interposed which biases the air in the opposite direction. Further, one end portion of a link 16 is rotatably connected to a predetermined position of the sub-rod 14 on the guide member 12 side. A midway portion of the link 16 includes a pair of support links 18 that stand vertically from the inner surface of the guide member 12.
It is rotatably supported between the upper ends of 18 via a pin 19. The other end of the link 16 is connected to the rod member 4
When the moving member 7 moves forward and backward, it comes into contact with the end face of the moving member 7. Therefore, when the movable member 7 moves from the support member 11 side to the guide member 12 side and hits the link 16, the sub-rod 14 resists the urging force of the spring 15 and moves from the guide member 12 side to the support member 11 side. Once moved. When the moving member 7 moves in the opposite direction from this state, the sub-rod 14 moves from the support member 11 side toward the guide member 12 side due to the urging force of the spring 15.

The microscale having the above-mentioned configuration is used, for example, in a mechanism for moving a stage of a microscope or the like. In this case, the guide member 12 is supported by a support stem A or the like, and the tip of the rod 4 is in contact with or connected to the stage.

As shown in FIG. 4, the sub-rod 14 is moved toward the guide member 12 by the biasing force of the compressed spring 15 within the permissible range of linear movement of the rod 4. That is, the end of the sub-rod 14 on the support member 11 side enters the hole 11a of the support member 11 and retreats from the rotational movement locus of the protrusion 34 of the operating member 3 (second position). Therefore, the operating member 3 can be freely rotated by grasping the knob 32. When the operating member 3 is rotated, the rotating shaft 2 fixed to the operating member 3 is rotated. When the rotating shaft 2 rotates, the moving member 7 screwed into the male threaded portion 6 of the rotating shaft 2 moves in the axial direction of the rotating shaft 2. When the moving member 7 moves, the rod 4 integrally attached to it also moves, and as the rod 4 moves, the stage is moved. The amount of movement of the moving member 7 and the rod 4 is one pitch of the male threaded portion 6 per rotation of the rotary shaft 2, and the amount of movement of the stage can be finely adjusted.

Note that during the above-described operation, the operating member 3 is not displaced relative to the scale body 1, and the length L of the microscale excluding the rod 4 is constant.

Further, the amount of movement of the stage, in other words, the amount of movement of the rod 4, can be detected as follows. When the rod 4 is moved in the axial direction, that is to say when the moving member 7 is moved, the mounting member 90 fixed thereto is moved in the same direction. As a result, the vernier scale 92 fixed to the attachment member 90 is linearly displaced with respect to the main scale 91. When the vernier 92 is displaced, the detection output of the light receiving element 94 is maximum when the stripes 95 and 96 of the main scale 91 and the vernier 92 completely overlap, and when they are shifted by 1/2 pitch (180 degrees). Minimum. This electrical output forms a sine wave with respect to the displacement of the vernier 92, pulses are obtained from this output using a known method, this pulse signal is counted by a counter, and the amount of movement is digitally displayed. Further, outputs having different phases from each other are obtained from the pair of light receiving elements 94, 94, and a direction discrimination signal is obtained by comparing these two outputs, and based on this signal, the counter selects addition or subtraction. For example, addition is performed when the rod 4 is moving forward, and subtraction is performed when the rod 4 is moving backward.

When the rod 4 reaches the limit of its allowable range, it is no longer possible to move forward. In this state,
If the operating member 3 is further turned, there is a risk that excessive stress will be applied to the male threaded portion 6 of the conversion mechanism 5 and the threads of the female threaded hole 70, causing them to collapse. However, in this invention, the above-mentioned disadvantages can be prevented by the following actions.

When the rod 4 advances just before exceeding the permissible range of forward movement, the end surface of the moving member 7 comes into contact with the end of the link 16 and presses this end, as shown in FIG. As a result, the link 16 rotates around the pin 19 of the pair of support links 18,
The sub-rod 14 is moved toward the support member 11 against the urging force of the spring 15. Then subrod 14
is located on the rotational movement locus of the protrusion 34 of the operating member 3 (first position). As a result, the protrusion 34 hits the end of the sub-rod 14, making it impossible to rotate the operating member 3. Therefore,
Rod 4 does not exceed the permissible range of forward movement.

This invention is not limited to the one embodiment described above, and various embodiments are possible. For example, the invention may be applied to limit the backward movement of the rod. Specifically, the movable member is provided with a short sub-rod parallel to the rotating shaft, and when the rod retreats just before exceeding the allowable range of backward movement, the end of the sub-rod passes through the hole in the support member and the protrusion of the operating member. The rotational movement of the operating member is prohibited.

(Effect of the invention) As explained above, in this invention, when the rod member exceeds the allowable forward/backward movement range due to rotation of the operating member in one direction, the engaging member engages with the operating member. The rod member is configured to prevent its rotation in one direction, and within the permissible range of forward and backward movement of the rod member, the engaging member separates from the operating member and allows rotation in that one direction. The operating member cannot be rotated before the allowable range of forward and backward movements is exceeded, and the rod does not exceed the allowable range of forward and backward movements. As a result, for example, the conversion mechanism for converting the rotational force of the operating member into linear movement of the rod is not deformed, and measurement errors caused by this deformation can be eliminated, allowing highly accurate measurement.

[Brief explanation of drawings]

The drawing shows an example of this invention.
Figure 1 is a microscale vertical cross-sectional view, Figure 2 is a cross-sectional view taken along the - line in Figure 1, and Figure 3 is a cross-sectional view taken along the - line in Figure 1. Figure 4 is a cross-sectional view showing the rod is within the allowable range of forward and backward movement, and Figure 5 is an enlarged comparison of a portion of the main and vernier scales. It is a diagram. 1...Scale body, 3...Operation member, 4...
Rod, 5... Conversion mechanism, 9... Detection device, 14
...Subrod (engaging member), 34...Protrusion,
40... Rod member, 50... Moving mechanism, 91...
...Main scale, 92... Vernier scale.

Claims (1)

[Scope of utility model registration request] A scale body, a rod member held by the scale body so as to be movable in the direction of its own axis, an operating member rotatably supported by the scale body, and a rotation of the operating member is controlled by the rod member. a conversion mechanism for converting the movement into a straight line; a main scale arranged along the axial direction of the rod member and fixed to the scale body; and arranged opposite to the main scale;
A vernier scale connected to the rod member so as to move in a straight line together with the rod member is provided, and the distance traveled by the rod member due to rotation of the operating member is measured by scanning the main scale with the vernier scale. In the microscale, the scale body has a first position that engages with the operating member to prevent rotation in one direction, and a second position that is separated from the operating member and allows rotation in one direction. An engaging member is provided between the engaging member and the rod member, and the engaging member is disposed so as to be movable between the engaging member and the rod member. The engaging member is moved from the second position to the first position, and the engaging member is moved to the first position by moving the rod member in a straight line by rotating the operating member in the other direction.
A microscale characterized in that it is provided with a movement mechanism for moving from a position to a second position.