JPH02221801A - Size measuring instrument - Google Patents

Abstract

PURPOSE:To take a high-accuracy measurement with uniform and fine measurement pressure by providing a slider, which can reciprocate associatively with an electric motor, with a parallel link mechanism, and providing a measuring element at one end part and a weight at the other end part. CONSTITUTION:The slider 27 which can reciprocate associatively with the electric motor 28 is provided with link members 51 and 52, the measuring element 67 is provided at one end part, and the weight 77 is provided at the other end part; and the specific measurement pressure is applied to a body to be measured through the measuring element 67 by the weight balance between the measuring element side and weight side of the slider 27. Then the electric motor 28 is driven first to elevate the slider 27 and the measuring element 67 is elevated by a specific quality above the body to be measured through the members 51 and 52 and a holder 55. Then the electric motor 28 is reversed to move down the slider 27, then the measuring element 67 abuts on the body to be measured and stops at the position, but the holder 55 and slider 27 move up and down relatively to make the members 51 and 52 rotate and slant. The slanting is detected by a rotation detecting means to stop the electric motor and the position of the measuring element 67 is detected by a displacement detecting means 74.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention moves a gauge head back and forth using an electric motor, and detects the amount of movement of the gauge head when it comes into contact with an object to be measured. The present invention relates to a dimension measuring device that measures the dimensions, etc. of an object to be measured.

[Background technology]

As a dimension measuring device that has a relatively large measurement range and can easily measure the dimensions of the object to be measured, for example, as shown in Japanese Patent Publication No. 58-10681, Japanese Patent Publication No. 59-19283, etc. 2. Description of the Related Art A dimension measuring device is known in which a measuring element is moved by an electric motor and brought into contact with the surface of an object to be measured under a predetermined pressure, and the amount of movement of the measuring element is detected.

In this type of conventional dimension measuring device, an electric motor is supported on a support body, and a nut member is screwed onto a feed screw shaft that rotates in conjunction with the electric motor. A spindle is supported by a support body so as to be reciprocally movable and has a measuring tip at one end so as to be able to be engaged and detached. A detecting means for detecting the relative movement of the spindle with respect to the nut member is provided, and a displacement detecting means for detecting the amount of movement of the spindle is further provided between the spindle and the support. .

were directly affected. Therefore, in conventional dimension measuring devices, for example, the hunting movement of a spring due to this frictional force,
Alternatively, in order to eliminate the influence of malfunction due to its own weight, a relatively large spring force or weight is required, making it impossible to measure with a uniform and minute measurement pressure. Therefore, there has been a problem in that it is not possible to achieve more accurate measurements that have been required in recent years or to measure flexible members that deform and become unmeasurable under large measurement pressures.

An object of the present invention is to provide a dimension measuring device capable of measuring dimensions with high precision using uniform and minute measuring pressure.

[Problem to be solved by the invention]

However, in conventional dimension measuring devices, the spindle is directly supported by the support so that it can move back and forth, and the solid friction force between the spindle and the support is inevitably large. Therefore, the biasing force due to the spring interposed between the spindle and the nut member or the spindle's own weight is caused by this frictional force. A link mechanism is provided, and a measuring element is provided at one end of this parallel link mechanism, and a weight is provided at the other end, and the weight balance between the measuring element side and the weight side of the slider is used to apply a predetermined measuring pressure to the measuring element. This is a dimension measuring device that can be applied to the object to be measured through the measuring device.

Specifically, the present invention provides a support, a slider held by the support so as to be able to move up and down, an electric motor and power transmission means for reciprocating the slider along the support, and first and second link members arranged at intervals and rotatably supported by the slider at their intermediate portions; and the slider is rotatably supported by one end of both of these link members. a parallel link mechanism configured to include a holder that can move in parallel with the holder; a measuring element provided at one end of the holder; and a measuring element provided at the other end of the first and/or second link member of the parallel link mechanism. a weight provided so that the weight of the holder side urges the probe downward with a slight urging force;
, rotation detection means for detecting rotation of the second link member;
Displacement detection means configured to include a main scale provided on either one of the holder and the support and a displacement detector provided on the other, and detects vertical displacement of the probe. This is a dimension measuring device.

[Effect]

In the above configuration, the electric motor is driven in advance to raise the slider via the power transmission means, and the probe is moved to the object to be measured via the first and second link members and the holder. ! 2 Raise the device by a predetermined amount relative to the device table.

Next, when the electric motor is reversed and the slider is lowered,
The probe also descends, contacts the object to be measured on the table, and stops at that position. On the other hand, at the moment when the slider stops, the slider is still moving in the downward direction, so the holder with the probe and the slider move relative to each other in the vertical direction, and both the first and second link members rotate. It will be tilted.

The inclination of both link members is detected by the rotation detecting means, the electric motor is stopped, and the position of the probe is detected by the displacement detecting means to measure the dimensions of the object to be measured.

During the measurement, the measuring element and the holder that holds the measuring element are not directly slidably supported on the support body as in the past, but are rotatable on the slider via the first and second link members. The weight on the holder side is almost balanced by the weight, and the biasing force is small.
The displacement of the probe is extremely smooth, and the measurement pressure is uniform and small.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 to 5 respectively show a longitudinal sectional view, a front view, a side view, a plan view, and a partially omitted exploded perspective view showing the main parts of this embodiment, and FIG. FIG. 7 is a cross-sectional view taken along the line Vl--Vl, and FIG. 7 is a perspective view of the overall structure of a measuring instrument incorporating this embodiment.

In FIG. 7, the measuring instrument 10 includes a base 11, and a column 12 erected on the base 11 has, for example, a protruding head portion 13 integrally formed therein. To this, a digital display 14 and an indicator lamp 1 are provided on the front of the RAD unit 13.
5 is provided, and a dimension measuring device 20 according to the present invention is incorporated inside. Further, a table 16 on which the object to be measured 5 is placed is provided on the upper surface of the base 11, and an operation panel 17 equipped with a power source, various other switches, etc. is incorporated in the front surface.

In FIGS. 1 to 6, the dimension measuring device 20 is equipped with a support 21. As shown in FIGS. This support body 21 includes a bottom plate 22,
The base plate 22 includes a substantially prismatic guide member 23 erected approximately at the center of the base plate 22, a top plate 24 fixed to the upper end of the guide member 23, and a side plate 25 protruding from one end of the base plate 22. There is.

A rectangular cylindrical slider 27 is supported by the guide member 23 so as to be slidable vertically and in directions along the guide member 23.
The slider 27 is driven vertically by an electric motor 28 fixed to the top plate 24 via a power transmission means 31. The power transmission means 31 includes a drive gear 32 fixed to the output shaft 29 of the electric motor 2, and this drive gear 3.
A feed gear shaft 34 is fixed to one end of the driven gear 33 meshed with the gear 2, and is supported between the top Fi 24 and the bottom plate 22 so as to be rotatable but immovable in the vertical direction. A nut member 35 is fitted to the slider 27 and fixed to the slider 27.

On the front and rear sides of the slider 27, as shown in FIGS.
A first link member 51 and a 72nd link member 52 made of two elongated plates in the front and back are attached to these points fi41 and 42 through bearings 43 and 44, respectively.
A substantially central portion of the is rotatably supported. At this time, the real shafts 41 and 42 and the bearings 43 and 44 constitute pivot bearings 45 and 46, respectively.

The first link member 51 and the second link member 52, each made of a pair of front and rear plates, are connected by connecting members 53 and 54 at one end (front end) slightly inside and the other end (rear end), respectively. The front and rear plates rotate as a unit.

The first link member 51 and the second link portion, material 52
A boulder 55 is provided between the front ends of the pivot bearings 5 and 5, respectively.
It is rotatably supported via 6.57. These pivot bearings 56.57 include a real shaft 58.59 whose both ends protrude from the holder 55 at a predetermined distance, and bearings 61.6 attached to the first and second link members 5152, respectively.
It is composed of 2. In addition, the upper and lower real axes 5B, 59
are set at equal intervals to the real shafts 41 and 42 protruding from the slider 27, so that the first and second link members 51
, 52, the slider 27, and the holder 55 constitute a parallel link mechanism 65.

The lower end of the holder 55 is loosely fitted into a through hole 22A formed in the bottom plate 22 of the support 21, and a measuring element 67 is attached to this lower end via a spindle 66 passing through the through hole 22A. It is being

On the other hand, a main scale 71 having a predetermined scale is vertically arranged in a notch 55A provided on one side of the holder 55 and is bonded thereto. The scale surface 71A of the main scale 71 and the axes of the spindle 66 and measuring element 67 are arranged on a straight line. On the side plate 25 at a position facing the main scale 71, there is an index scale 72 having a predetermined scale, and a displacement detector 73 including a light source, a light receiving element, and a detection circuit (not shown).
is provided so that the displacement of the measuring stylus 67 relative to the support 21 and the main scale 71, that is, the support 21, can be detected. Here, the main scale 71
The displacement detector 73 constitutes a displacement detecting means 74 that detects vertical displacement of the measuring stylus 67.

A disk-shaped weight 77 is rotatably screwed into the connecting member 54 that connects the rear end side of the second link member 52 via a screw shaft 76. The position is fixed by a lock nut 78.

The position of the weight 77 is between the first and second link members 51 and 52.
A holder 55 and a main scale 71 connected to one end of the
, the weight of the spindle 66, measuring head 67, etc., i.e.,
The moment that urges the first and second link members 51, 52 in the counterclockwise direction in FIG. 7
The moment of rotating the first and second link members 51 and 52 clockwise based on the weight of the lock nut 78 and the lock nut 78, etc. is almost balanced, and the moment of the holder 55 is set at a position that is slightly larger. . That is, the weight 77 is set at such a position that the probe 67 is biased downward with a slight biasing force. Therefore, the first and second link members 51 and 52 are normally urged to rotate counterclockwise in the figure, and the measuring stylus 67 is always trying to move downward; The rotation of the second link members 51 and 52 in both the clockwise and counterclockwise directions is restricted by rotation restricting means 79 consisting of L-shaped brackets provided on the front and rear side walls of the slider 27, respectively. , the measuring element 67 side is slightly lowered and stopped in contact with the rotation regulating means 79. At this time, the gap between the rotation restricting means 79 and the first and second link members 51.52 is made small, and the first and second link members 51.5
The inclination angle of No. 2 is also a small angle.

A substantially T-shaped operating piece 81 is fixed to one side of the first link member 51, that is, the plate on the near side in FIG. 2.5, at the position of the bearing 43. is extended to the vicinity of the second link member 52 and bent outward, and a slit 82 is formed in this bent portion. At a position facing the actuating piece 81, a bearing layer 8 is provided between the bottom plate 22 and the top plate 24, which is screwed to the bottom plate 22 and the top plate 24, respectively, and has a recess 83 formed on the opposing surface.
4, the support shaft 85 is rotatably supported. An operating shaft 87 is fixed to this support shaft 85 in parallel with the support shaft 85 via a pair of upper and lower operating shaft holding members 86.
7 is engaged with the slit 82 of the actuating piece 81.

Therefore, when the actuation piece 81 rotates and tilts together with the first link member 51, the actuation shaft 87 turns around the support shaft 85, and accordingly, the actuation shaft holding member 86 and the support shaft 85
It also rotates. Further, a shirt flap plate 88 is fixed to the lower operating shaft holding member 86. This shirt shirt plate 88 is inserted into a U-shaped groove of a U-shaped photo ink converter 89 having a light emitting section and a light receiving section, and can change the amount of light emitted from the light emitting section and received by the light receiving section. ing. This photo ink printer 89 has a bottom plate 2.
It is attached to a retaining plate 91 erected at 2. Here, the operating piece 81, the bearing layer 84, the support shaft 85, the operating shaft holding member 86, the operating shaft 87, the shank plate 8B, the photo ink club 89, and the holding plate 91 are used to control the fifteenth second link member 51.52. A rotation detection means 92 for detecting rotation is configured.

In addition, in the head part 13 of the measuring device IO in FIG.
A control means 101 is provided behind the dimension measuring device 20. The control means 101 is connected to the digital display 14, the operation panel 17, the electric motor 28, the displacement detector 73, and the photo ink club 89, and is connected to the operation panel 17.
According to the operation, the displacement detected by the displacement detector 73 is displayed on the digital display 14, and the electric motor 2 is driven by signals from the operation panel 17 and the photointerrupter 89. Further, reference numeral 38 is a light shielding plate provided on the back side of the main scale 71.

Next, the operation of this embodiment will be explained.

At the start of measurement, the operation panel 1 is placed without placing the object 5 to be measured on the table 16 of the measuring machine 10 shown in FIG.
7 is pressed to drive the electric motor 28 via the control means 101. By driving this electric a2B,
The slider 27 is raised via the power transmission means 31, and as a result, the first and second link members 51, 52, and the holder 5
5 and spindle 66, the probe 67 is raised by a predetermined amount and then stopped.

Next, when the electric motor 28 is driven in reverse, the probe 67 is lowered, comes into contact with the upper surface of the table 16 and is stopped, and the holder 55 is also stopped via the spindle 66. on the other hand,
At the moment when the contact point 67 comes into contact with the table 16, the slider 27 is driven in the downward direction by the electric motor 2.
Therefore, the holder 55 and the slider 27 move relative to each other in the vertical direction. As a result, the first and second link members 51.52 rotate clockwise about the pivot bearings 45.46 and tilt. Along with the inclination of the first link member 51, the actuating piece 81 also rotates clockwise and inclines, and the inclination of the actuating piece 81 is transmitted to the actuating shaft 87 through the slit 82, and the actuating shaft holding member 86 At the same time, the shirt shirt plate 88 is driven counterclockwise about the support shaft 85 when viewed from above. As the shutter plate 88 rotates, the light receiving lid of the photo ink club B9 changes, and the change in the amount of light received by the photo ink club B9 is converted into an electrical signal and input to the control means 101. The control means 101 compares a preset reference signal with the electric signal, and when the electric signal becomes equal to or less than the reference signal, the value displayed on the digital display 14 is held, as will be described later, and the electric motor is 28 is stopped.

Further, the vertical displacement of the probe 67, that is, the holder 55, is detected by the main scale 71 and the displacement detector 73, and the signals from the displacement detector 73 are sequentially displayed on the digital display 14 via the control means 101. ing. At this time, an electrical signal based on a change in the amount of light received from the photo ink clubter 89 of the rotation detecting means 92 is input, and when it becomes less than the reference signal, the digital display is displayed by the action of the control means 101 as described above. Display is held.

At this time, since the object to be measured 5 is not placed on the table 16, the reset button on the operation panel 17 is pressed at the position where the probe 67 hits the top surface of the table 16, and the digital display 2314 is Set display to zero.

Next, the lift switch on the operation panel I7 is pressed to drive the electric @2B to raise the probe 67 by a predetermined amount, that is, by a range that allows insertion of the object to be measured 5, and then stops. In this state, when the object to be measured 5 is placed on the table 16 and the measurement switch on the operation panel I7 is operated, the measuring element 67 is driven in the downward direction, and the measuring element 67 comes into contact with the upper surface of the object to be measured 5. . At this time, as described above, the holder 55 and the slider 27 are vertically displaced relative to each other, and the first and second link members 5! .

52 rotates, and this rotation is detected by the rotation detecting means 92 via the actuating piece 81. By detecting this rotation, the digital display 14 displays the measuring stylus 67 from the displacement detecting means 74.
The displacement is displayed, and this displayed value is taken as the height dimension of the object to be measured.

When measuring the height dimension of the object to be measured 5, the first
, the rotation of the second link members 51, 52 is carried out extremely smoothly. That is, in order to displace the probe 67 with respect to the slider 27, the weight of the holder 55 and the weight 77 are required.
(!) In addition to the rotational force (biasing force) based on the difference from the weight of However, in this embodiment, these N friction torques are extremely small.To be more specific, as shown in FIG.
The slider 27 and each link member 51.
52 and the distance I1 from the center of rotation of each link member 51, 520 relative to the holder 55 to the position where the frictional force acts between the holder 55 and each link member 51, 52. ．． are both equal,
Moreover, it is extremely small compared to the distance 1i1L between these two rotation centers. Therefore, the force applied to the measuring element 67 due to the lever action exceeds the biasing force based on the weight difference, that is, each link member 51 Even if the moment that tries to rotate the first and second link members 51 and 52 acting on both pivot points of .52 is extremely small, each pivot bearing 45, 4
This is because it is possible to easily obtain a moment that overcomes the friction torque at 6, 56, and 57. In other words,
The force of contact of the probe 67 against the object to be measured 5, that is, the measurement pressure, can be made extremely small.

Further, when rotating the first and second link members 51 and 52, a force is also required to rotate the rotation detection means 92, but the rotation force of this rotation detection means 92 is also extremely small. That is, the support shaft 85 of the rotation detecting means 92 is supported by a bearing surface 84 having a bowl-shaped recess 83 on its upper and lower sides, and the tip of the support shaft 85 is formed sharply. This is because it is located in

For this reason, by appropriately setting the position of the weight 77 with respect to the screw shaft 76, the probe 67 can contact the object to be measured 5 and rotate the first and second link members 51 and 52. This means that the force to be measured, or conversely, the measurement pressure of the probe 67 can be made extremely small.

After completing the measurement of the dimensions at a predetermined position of the object to be measured 5 as described above, raise the measuring stylus 67 again and replace the object to be measured 5, or measure a different position of the same object to be measured 5. The next measurement is performed by positioning the probe 67 below the child 67, and the subsequent measurements are repeated in the same manner. Since this measurement result is displayed on the display 14, it can be read and recorded, or the output can be sent to a printer or the like that is not reprinted and printed.

According to this embodiment as described above, there are the following effects.

That is, in this embodiment, the spindle 66 to which the gauge head 67 is attached is not directly supported by a bearing or the like, but is rotatably supported via the parallel link mechanism 65, and the weight balance of the parallel link mechanism 65 is is set by the weight 77, and the rotation of the first and second link members 51 and 52 of the parallel link mechanism 65 is detected by the rotation detection means 92. The driving force that accompanies movement, that is, the urging force, can be extremely small, and even if the object to be measured 5 is a member that is easily deformed, such as the outer ring of a ball hair ring, or a flexible member, accurate measurement can be made. Can be done. More specifically, the measuring force of the measuring head 67 can be made to about Igf, which is 1/100 to 1/20 compared to the conventional method.
It can be set to a value of 0. Further, in this measurement, deformation such as Hertzian elastic deformation does not occur, and measurement can be performed with high resolution in submicron units. Furthermore, holder 5
The scale surface 71A of the main scale 71 can be placed on the extension of the central axis of the spindle 66 to which the measuring stylus 67 is attached due to the action of the cutout 55A of the stylus 67. The parts are arranged in a straight line, making it possible to construct a measurement system that follows the so-called Atsube's principle, which also allows for highly accurate measurements.

Further, since the slider 27 and the guide member 23 have a rectangular cross section, they do not require any special rotation prevention device and have a robust structure, so that highly accurate feeding can be performed. Furthermore, a rotation detection means 92 for detecting the rotation of the first and second link members 51 and 52 of the parallel link mechanism 65 is configured so that the photo ink club 89, which requires electrical wiring, is located on the side of the parallel link mechanism 65. Since the slider 27 is fixedly provided on the guide member 23, the wiring and the like do not get in the way when the slider 27 moves relative to the guide member 23, and malfunction of the device can be prevented. In addition, since the photo ink club 89 is provided at a fixed position 1, there is no risk of characteristic changes, and from this point of view as well, highly accurate measurement is possible.

Note that the present invention is not limited to the above embodiments,
The present invention includes modifications within a range that can achieve the object of the present invention. That is, the dimension measuring device 20 according to the present invention does not necessarily include the measuring machine 10, as shown in FIG.
The measurement device 2 is not limited to the one built into the head section 13 of the
0 may be configured as a single item, and this measuring device 2o may be attached to a general measuring stand or the like to perform measurements.

Furthermore, although the first and second link members 51 and 52 constituting the parallel link mechanism 65 are each formed from a pair of plate materials, they may each be formed from a single plate material.
In this case, the bearing structure between the eleventh and second link members 51 and 52 and the slider 27 may be a cantilever structure similar to the embodiment described above, or alternatively, the bearing structure between the eleventh and second link members 51 and 52 and the slider 27 may be a cantilever structure as in the previous embodiment, or the bearing structure from the slider 27 to the first. An L-shaped bracket may be provided corresponding to each of the second link members 51 and 52, and the pivot shaft may be supported between the bracket and the slider 27 in a dual-supported state.
Further, the support of the parallel link mechanism 65 is not limited to the pivot bearings 45, 46 as in the above embodiment, but may be supported by other general bearings.
The use of the pivot bearing 4546 has the advantage that the parallel link mechanism 65 can be incorporated easily and accurately, and the rotational torque can be extremely small. Also, the first
Although the second link members 51, 52 are supported at their substantially central positions by the pivot bearings 45, 46 so as to be able to substantially balance their weight by themselves, this need not necessarily be the case.

However, the above embodiment has the advantage that processing and assembly are easy. Further, although the weight 77 is provided on the second link member 52 side, it may be provided on the first link member 51 side, or even on both link members 51 and 52. Although the weight 77 is adjustable on the screw shaft 76, it does not necessarily have to be adjustable and may be fixed. However, if it is adjustable, the biasing force of the probe 67 can be set extremely precisely, which is advantageous for measurement. Furthermore, the other end portions of the first and second link members 5152, that is, the end portions on the side where the weight 77 is provided, are connected by link members extending in the vertical direction to form a so-called donkey pal mechanism. , this donkey is like a so-called balance.
It is also possible to balance the weight using the pal mechanism. Further, the rotation detection means 92 is not limited to the structure of the above embodiment, and the photo ink club 89 is connected to the slider 27 via a bracket.
is installed so that at least one of the first and second link members 51 and 52 is inserted into the U-shaped groove of the photointerrupter 89, and the eleventh second link member 51
．． The rotation of 52 may be directly detected. However, in this case, since the slider 27 moves along the guide member 23, the lead wire from the photo ink printer 89 is moved along with the movement of the slider 27, which is disadvantageous in that it may get in the way of the movement. It is. Further, the detection means of the rotation detection means 92 is not limited to the photo ink club 89, but may be a detection means using a rotary encoder, a magnetic sensor, a laser beam, etc. The power transmission means 31 is not limited to the one using the feed screw shaft 34 as in the above embodiment, but for example, a rack or the like.
Other mechanisms such as a pinion mechanism may be used. Also, the electric motor 28 is not limited to the one provided on the support body 21 side, and the electric motor 28 is not limited to the one provided on the support body 21 side.
However, the above embodiment is more advantageous in terms of reducing the weight of the slider 27, which is a moving member.

〔Effect of the invention〕

According to the present invention as described above, there is an effect that the object to be measured can be measured with high precision using a uniform and minute measuring force.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a longitudinal sectional view of the embodiment, Fig. 2 is a front view thereof, Fig. 3 is a side view, and Fig. 4 is a partially cutaway view. A plan view, FIG. 5 is an exploded perspective view with some parts omitted, FIG. 6 is an enlarged sectional view taken along the line Vl-Vl in FIG. 1, and FIG. 7 is a perspective view showing a measuring machine incorporating this embodiment. It is. 5... Object to be measured, 20... Dimension measuring device, 21...
- Support body, 27... Slider, 28... Electric motor, 3
1... Power transmission means, 51... First link member,
52... Second link member, 55... Holder, 65
...Parallel link 41fl, 67...Measuring point, 71.
...Main scale, 73...Displacement detector, 74...
・Displacement detection means, 77... Weight, ... Rotation detection means.

Claims (1)

[Claims] (1) A support, a slider held by the support so as to be movable up and down, and an electric motor and power transmission means for reciprocating the slider along the support, arranged at predetermined intervals in the vertical direction. and first and second link members whose intermediate portions are rotatably supported by the slider, and which are rotatably supported by one end of both of these link members and can move parallel to the slider. a parallel link mechanism including a holder, a measuring element provided at one end of the holder, and a first and/or
or a weight provided at the other end of the second link member and set so that the measuring element is biased downward with a slight biasing force by the weight of the holder, and the first and second links. A rotation detecting means for detecting rotation of a member, a main scale provided on one of the holder and the support, and a displacement detector provided on the other, and detects vertical displacement of the measuring stylus. A dimension measuring device characterized by comprising a displacement detecting means for detecting displacement.