JP2009300301A - Displacement measuring tool and displacement measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement measuring tool and displacement measuring device capable of accurately measuring dimensions and the like of a workpiece having a narrow opening or a depth. <P>SOLUTION: The displacement measuring tool includes: a spindle 3 capable of freely moving to the axis direction; a dial gauge 2 for measuring the moving displacement of the spindle 3; an arm 7 cantilevered by the spindle 3 and extending to the direction perpendicular to the axis direction of the spindle 3; a gauge 4 disposed at a predetermined distance from the spindle 3 of the arm 7 and making contact with an object to be measured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a displacement measuring jig and a displacement measuring device for measuring a dimension or the like by bringing a measuring element into contact with a measurement object.

  Conventionally, for various types of objects to be measured (hereinafter referred to as workpieces), there have been investigations on measuring methods that take into account the coefficient of friction using measuring elements in accordance with the shape or measuring elements that have been devised. Has been done. As such an example, the techniques described in Patent Document 1 and Patent Document 2 are known.

  In Patent Document 1, it is described that a knife-edge-shaped probe is brought into contact with the edge portion of a workpiece, and an abnormality in the edge portion is detected based on the force generated by the probe.

In Patent Document 2, a part that is in contact with the workpiece is brought into contact with the surface of the workpiece with a shape and material similar to the workpiece, and moved in a horizontal direction in a predetermined pressure state. The fact that the coefficient of friction of the workpiece surface is collected is described.
JP-A-8-5364 JP-A-11-31723

  However, in an apparatus having a characteristic measuring element described in Patent Document 1 or Patent Document 2, a cylindrical shape as shown in FIGS. 11 (a) (b) and 12 (a) (b). It does not measure the size of the internal shape of the narrow through-holes of the members.

  Therefore, when measuring the internal shape of a cylindrical member or the like as shown in FIG. 11 or FIG. 12, a commercial product such as a test indicator (lever type dial gauge) or a dial gauge is modified as shown in FIG. It is possible to measure using Before conducting such examination, the test indicator can be used for measurement of an internal shape having a narrow opening such as the above-described through hole. However, as is generally well known, the test indicator has a large error if it takes an angle of the probe that makes contact with the measurement surface of the workpiece too much (too high with respect to the measurement surface). (See the NG example shown in the square frame in FIG. 14A). In other words, an error occurs when the inclination angle θ of the test indicator stylus shown in FIG. Here, an error generated according to the angle θ [deg] is abbreviated as an error (θ). The error (θ), which is a function of the angle θ, is on the smaller side with respect to the indicated value of the test indicator. The value of 1-error (θ) is 1-error (θ = 1) = 0.9997 when θ is 1 degree, 0.981 when θ is 10 degrees, and 0 when θ is 30 degrees. The higher the angle, .863, the greater the error. When the step b1 in the through hole of the cylindrical member shown in FIG. 12B is measured, when the step b1 is 3 mm, the error increases from 3 × 0.9997 to 3 × 0.863. Furthermore, when measuring the internal shape (the inner diameter of the workpiece, etc.) having a depth b3 in the through hole of the cylindrical member shown in FIG. 12B, a test is performed to bring the probe into contact with the inner side of the through hole. When the arm of the indicator is extended as shown in FIG. 14B, there is a problem that the error is further increased. Due to concerns about such an adverse effect, the countermeasure product shown in FIG. 14B in which the arm is extended from the commercial product (conventional product) is not used.

  On the other hand, it is said that the dial gauge that is generally distributed as a commercial product as shown in FIG. 14 (c) has less error and better accuracy than the test indicator. In contrast, when the opening b2 of the cylindrical member in FIG. 12 (b) is small, the dial gauge body is inclined to bring the probe into contact with the inner wall of the workpiece (inside the rectangular frame in FIG. 14 (c)). NG), the probe cannot be set correctly at the workpiece measurement site. That is, even with dial gauges that have been used in the past, it is difficult to accurately measure the inner wall of a cylindrical member or the like with a narrow opening as it is on the market, so that accurate measurement can be performed. The dial gauge needs to be improved.

  That is, in the conventional test indicator or dial gauge, when the workpiece having a deep shape is measured, the contact state of the measuring element with respect to the measurement site is as shown in FIGS. 14 (a) and 14 (c). Therefore, there is a need for a jig and apparatus configuration for correctly setting a measuring element at a target measurement position so that the dimensions can be accurately measured while avoiding the NG example.

  Accordingly, an object of the present invention is to provide a displacement amount measuring jig and a displacement amount measuring apparatus capable of accurately measuring the dimensions of a workpiece having a narrow opening or a deep opening.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, in claim 1,
A displacement amount measuring means having a spindle movable in the axial direction and measuring a displacement amount of the spindle;
An arm that is cantilevered by the spindle and extends in a direction perpendicular to the axial direction of the spindle;
A measuring element that is provided at a position spaced apart from the spindle of the arm by a predetermined dimension and that contacts the object to be measured.

In claim 2,
The displacement amount measuring means is a dial gauge.

In claim 3,
The displacement amount measuring jig according to claim 1 or 2,
Fixing means for fixing the object to be measured;
A mounting table on which the displacement measuring jig is mounted and fixed;
A measuring instrument guide configured to move the mounting table in a direction in which the mounting table is moved toward and away from the object to be measured, and to guide the measuring element to a measurement site of the measuring object by sliding the mounting table to the measuring object side. Means,
A position measuring means for contacting the mounting table and driving the mounting table toward the object to be measured, and measuring a position of the measuring element in the sliding direction.

Further, the features of the present invention will be described more specifically with reference to FIG.
FIGS. 13A and 13B show a state in which the uneven surface of the workpiece is measured with the dial gauge as an example of measurement with a dial gauge conventionally performed.
Each arrow in FIGS. 13 (a) and 13 (b) indicates the position of the contact point between the gauge gauge probe formed in a substantially spherical shape and the uneven surface of the workpiece. For example, when the contact point is located at the lowest point of the probe, the arrow points directly upward, and as the contact moves laterally from the lowest point of the probe, the inclination angle of the arrow is It will increase.
When the arrow is extremely inclined, the contact may slip, and the dial gauge may be moved from the measurement point or damaged. That is, it is said that applying a force from the side to the dial gauge is not qualitatively good, but normally a force from the side is applied when measuring the uneven surface of the workpiece. That is, it can be easily analogized that the lateral force changes as the direction of the arrow changes due to the influence of various measurements. From this, it is considered that a predetermined range of moments is also allowed in the measurement using the dial gauge.
As described above, the present invention is characterized by positively utilizing the range of moments allowed in the dial gauge and intentionally applying a moment within the allowable range to the spindle.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, it is difficult to abut the measuring element by performing the measurement using the measuring element provided at the end of the arm formed in a cantilever shape and spaced apart from the spindle by a predetermined dimension. It is possible to accurately measure the dimension of a member having a narrow or deep opening. Further, by utilizing the bending force of the arm generated at the time of measurement, the clearance can be removed in a specific direction, and the backlash of the spindle can be reduced to improve the measurement accuracy.

  According to claim 2, it is difficult to bring the measuring element into contact by performing measurement using a measuring element provided at an end portion of the arm formed in a cantilever shape and spaced apart from the spindle by a predetermined dimension. It is possible to accurately measure the dimension of a member having a narrow or deep opening. Further, by utilizing the bending force of the arm generated at the time of measurement, the clearance can be removed in a specific direction, and the backlash of the spindle can be reduced to improve the measurement accuracy.

  In claim 3, when measuring a member having a narrow opening or a deep depth, the posture of the displacement measuring jig is maintained so as not to cause an error, and the measuring part can be easily aimed at the measuring element. It can be made to contact.

Next, embodiments of the invention will be described.
FIG. 1 is a side view showing the entire configuration of a displacement measuring jig according to an embodiment of the present invention, FIG. 2 is a perspective view, FIG. 3 is a partially broken sectional view, and FIG. FIG. (B) is a partially broken side view. FIG. 4 is an explanatory view showing a state of the spindle in which a bending force is generated, FIG. 5 is a view showing a relationship of an expected bearing portion reaction force with respect to a load position, and FIG. 6 is a cross-sectional view showing a main part of a dial gauge according to another embodiment. 7 is a sectional view, FIG. 8 is a perspective view showing a base according to the embodiment, FIG. 9 is a perspective view showing a displacement measuring device according to the embodiment, FIG. 10 is a perspective view, and FIG. It is a figure shown, (a) is a perspective view, (b) is AA arrow sectional drawing in (a). 12A and 12B are views showing a workpiece, wherein FIG. 12A is a perspective view, and FIG. 12B is a cross-sectional view taken along line AA in FIG. FIG. 13 is an explanatory view showing a measurement state using a conventional dial gauge, where (a) is a side view and (b) is a front view. FIG. 14 shows a conventional test indicator and dial gauge.
In addition, the same code | symbol is attached | subjected to the member which has the same use and function, and the description is abbreviate | omitted.

  As shown in FIGS. 1, 2, and 3, the displacement amount measuring jig 1 according to the present embodiment (hereinafter referred to as a measuring jig 1) includes a spindle 3 that is movable in the axial direction, and the spindle 3. A dial gauge 2 which is a displacement amount measuring means for measuring the amount of movement displacement, an arm 7 formed in a cantilever shape from the spindle 3, and provided at one end of the arm 7 at a predetermined distance from the spindle 3. And a first measuring element 4 that abuts against the workpiece 6. The displacement measuring device 30 described later is configured by mounting and fixing the measuring jig 1 at a predetermined position in the displacement measuring device 30. Below, each structure of the said measuring jig 1 is demonstrated concretely.

  The dial gauge 2 is a rotary needle display type dial gauge. The dial gauge 2 has a cylindrical casing 2a which is a case of the dial gauge 2 body, a second measuring element 8 at the tip, and is supported so as to be movable in the axial direction. The spindle 3, the stem 10 for guiding the spindle 3 in the axial direction, the bearing portions 21 and 22 (FIG. 3) for movably supporting the spindle 3, and the display means to be described later for the axial displacement of the spindle 3 5, a displacement amount transmitting means 17 that transmits to the spindle 5, a spring 18 that biases the spindle 3 toward the second probe 8, and an axial movement of the spindle 3 that is transmitted by the displacement amount transmitting means 17. It is mainly comprised from the display means 5 which displays displacement amount.

  The spindle 3 is a rod-shaped member, and a second measuring element 8 is provided at one end of the spindle 3, and the other end of the spindle 3 penetrates the housing 2 a through the stem 10. The spindle 3 is inserted and supported by bearings 21 and 22 described later, and is movable in the axial direction. In addition, one end of an arm 7 to be described later is integrally connected to a midway portion of the spindle 3 protruding from the stem 10.

  The stem 10 is a cylindrical member connected in communication with the housing 2a, and protects the spindle 3 and guides the spindle 3 in the axial direction.

The bearing portions 21 and 22 are cylindrical members made of metal or plastic with good slidability. As shown in FIG. 3, the moving direction (axial direction) of the spindle 3 in each of the housing 2a and the stem 10 is shown. Are arranged opposite to each other. The bearing portion 21 is fixed to the distal end side of the inner wall of the stem 10. The bearing portion 22 is fixed around the through hole of the housing 2a through which the other end (the upper end in FIG. 3A) of the spindle 3 passes. The spindle 3 is supported so as to be movable in the axial direction by being inserted into each of bearing portions 21 and 22 fixed to the inner wall of the stem 10 and the housing 2a.
Further, a slight clearance is provided between the outer peripheral portion of the spindle 3 and the inner peripheral portions of the bearing portions 21 and 22 in order to maintain slidability and prevent wear due to friction. .

  As shown in FIG. 3A, the displacement amount transmission means 17 is a mechanical transmission means for enlarging the movement displacement amount in the axial direction of the spindle 3 by the enlargement mechanism of the rack and pinion and transmitting it to the display means 5. , Rack 11, first pinion 12, large gear 13, and second pinion 14.

As shown in FIG. 3, the rack 11 is fixed to a side portion of a substantially central portion in the longitudinal direction of the spindle 3, and the first pinion is rotatably supported on the inner wall of the housing 2 a by the rack 11. 12 is engaged. The first pinion 12 includes a large gear 13 integrated on the outer periphery thereof, and a tooth portion 13 a (FIG. 3B) on the outer periphery of the large gear 13 and above the first pinion 12. The arranged second pinion 14 meshes. As a result, the displacement amount transmitting means 17 can transmit the displacement amount of the spindle 3 to the display means 5 by enlarging the amount of rotation (rotation angle) of the long hands 16 a and the short hands 16 b as the hands 16.
The displacement amount transmission means 17 is not particularly limited to the above-described mechanical transmission means using a rack and a pinion, and may be an electronic transmission means used in a digital dial gauge.

  The urging means is a spring 18 that is an elastic body that urges the spindle 3 toward the outside of the housing 2 a, and one end of the spring 18 is locked to the inner wall of the housing 2 a. The end is locked to a locking rod connected to a midway part of the spindle 3. Due to the action of the spring 18, the spindle 3 is always biased to one end side (second measuring element 8 side) of the spindle 3, and the first measuring element 4 is brought into contact with the shape of the work 6. Can be made.

The display means 5 is a means for displaying the movement displacement amount in the axial direction of the spindle 3 transmitted by the displacement amount transmission means 17, and is provided on the front surface of the housing 2 a of the dial gauge 2. The display means 5 includes a scale plate 15 on which a predetermined scale is displayed, and a long hand 16 a and a short hand 16 b which are pointers 16 indicating the displacement of the spindle 3. The long needle 16a is integrally connected to the second pinion 14, and the short hand 16b is integrally connected to the first pinion 12. Thereby, the display means 5 can rotate the long hand 16a and the short hand 16b in accordance with the amount of displacement of the spindle 3 in the axial direction, and the value indicated by the long hand 16a and the short hand 16b on the scale plate 15 is measured by the operator. Is read as In other words, the display means 5 indicates the displacement amount obtained by enlarging the movement displacement amount of the spindle 3 in the axial direction by the displacement amount transmission means 17 by the enlargement mechanism of the rack and pinion as the rotation amount (rotation angle) of the pointer 16. It is a means for displaying.
In the present embodiment, an analog display type dial gauge that indicates a measured value by the amount of rotation (rotation angle) of the long hand 16a and the short hand 16b is used as the display means 5, but is not particularly limited. It is also possible to use a digital display type dial gauge that digitally displays the amount of movement displacement.

One end of the arm 7 is integrally connected to the middle portion of the spindle 3 and is cantilevered by the spindle 3. The arm 7 extends from the middle part of the spindle 3 in a vertical direction (a direction orthogonal to the axial direction of the spindle 3).
The other end of the arm 7 is spaced apart from the second measuring element 8 coaxially provided at one end of the spindle 3 by a predetermined size and protrudes in the same direction and shape as the second measuring element 8. A first probe 4 is provided. That is, the arm 7 is formed to be cantilevered from the spindle 3 by connecting and supporting one end of the arm 7 to the middle part of the spindle 3. A3 is provided at a position spaced apart from the axis A2 of the spindle 3 of the arm 7 by a predetermined dimension M. Thus, the axis A2 of the spindle 3 and the axis A3 of the first measuring element 4 provided at the other end of the arm 7 are separated by a predetermined dimension M.
When measuring the workpiece 6 with the measuring jig 1, the first measuring element 4 is brought into contact with the measurement site of the workpiece 6, and the displacement amount of the first measuring element 4 is transmitted to the spindle 3 via the arm 7. Thus, the dimension of the workpiece 6 can be measured.
The arm 7 is not limited to the above-described configuration, and it is sufficient that the arm 7 is formed in a cantilever shape with respect to the spindle 3 so that a minute bending force described later acts on the spindle 3. For example, the spindle 3 and the arm 7 can be formed by integral molding to form the arm 7 in a cantilever shape. Moreover, what is necessary is just to select suitably whether the 2nd probe 8 is provided in the front-end | tip part of the spindle 3 as needed.

Next, a method of setting the separation distance M between the first measuring element 4 and the second measuring element 8 that are separated by a predetermined dimension via the arm 7 will be described.
As shown in FIG. 1, in a measuring jig 1 having a first measuring element 4 provided at a position separated from the second measuring element 8 (spindle 3) by a separation distance M, the first measuring element 4 and the second measuring element 4 are used. It is assumed that a slight difference occurs in the measurement results of the first measuring element 4 and the second measuring element 8 when measuring the workpiece 6 having the same shape in each of the elements 8.
As a cause of the difference in the measurement result as described above, the position of the second measuring element 8 which is a normal measuring element of the dial gauge 2, that is, the measuring element originally provided for contacting the object to be measured ( Since the measurement with the first measuring element 4 which is separated from the axis A2) of the spindle 3 by the distance M is a measurement in an unspecified area for the dial gauge 2, the distance M and the first measuring element 4 are set to the workpiece 6. This is because the product (M × Pm) of the measurement pressure Pm, which is the pressure received when the contact is made, contacts the point A1 at one end of the arm 7 as a bending force.

  That is, if the surface including the point of application of the measurement pressure Pm and the axis A2 that receives this bending force is the surface B, a bending force is generated at the point A1 in the surface B. This bending force increases the amount of movement in the Y-axis direction, which is the amount of bending of the cantilevered arm 7 whose length is the separation distance M. In other words, this is because the movement amount of the first probe 4 that has received the measurement pressure Pm is larger than the movement amount of the second probe 8.

  In the dial gauge 2 designed in advance so that the spindle 3 and the second measuring element 8 at the tip thereof move together, the measurement by the first measuring element 4 provided on the spindle 3 via the arm 7 is performed by the separation distance M. Depending on the setting of, an error may be included. That is, when the separation distance M is increased, the bending force generated at the point A1 is also increased, and the error is accordingly increased.

However, even in the measurement with the conventional spindle, as described above with reference to FIG. 13, since the measurement can be carried out without any problem in a specific bending force range, the bending force range can be set even in the state including the above error. It is thought that practical use is sufficiently possible by limiting.
In other words, in the present invention, the range of the bending force is limited, the occurrence of an error is allowed, the bending force (moment) of M × Pm is applied in a preload manner, and the clearance of the measuring system ( The clearance between the outer peripheral portion of the spindle 3 and the inner wall of the bearing portions 21 and 22) is removed in a specific direction, and the measurement accuracy can be improved by intentionally reducing the backlash of the spindle 3 due to the clearance. .

Specifically, in limiting the range of the bending force, the principle of reducing the backlash of the spindle 3 by the bending force will be described with reference to FIG. 4 based on the configuration of the measuring jig 1 described above.
FIG. 4 schematically shows a state in which the spindle 3 and the arm 7 connected to the spindle 3 are assumed as an integral cantilever for explaining how to apply a bending force to the spindle 3. It is explanatory drawing. As described above, the bearing portions 21 and 22 are disposed inside the dial gauge 2 in the present embodiment so as to face the moving direction (axial direction) of the spindle 3, and in FIG. 2 shows a state in which the spindle 3, the arm 7 and the bearing portions 21 and 22 are partially viewed in section.

As shown in FIG. 4, when the measurement pressure Pm is applied to the end of the arm 7 (the part where the first measuring element 4 is located) in the order of zero → small → normal weight addition, the spindle 3 and the arm 7 Thus, the shape of the cantilever changes in the form of shape e1 → shape e2 → shape e7 according to the degree of weighting. Here, e7 is a state of bending in a cantilever manner. In the shapes e2 and e7, the clearance between the outer peripheral portion of the spindle 3 and e3 of the bearing portion 21 and e4 of the bearing portion 22 is reduced.
That is, in the shape e7 to which the normal load is applied, the other end of the arm 7 is lifted upward, and one end of the arm 7 is pulled toward the other end side of the arm 7 accordingly. Due to the attracted effect, the spindle 3 is bent and is in contact with a part of the inner circumference of each of the bearing portions 21 and 22 (in FIG. 4, it contacts the e3 of the bearing portion 21 and the e4 of the bearing portion 22). This is a state in which the spindle 3 is preloaded (preloaded) in a so-called fixed direction with respect to the bearing portions 21 and 22. By intentionally applying such a pre-load in a certain direction to the bearing portions 21 and 22 within the allowable range of the dial gauge 2, the spindle 3 is prevented from being influenced by friction and is originally caused by a minute clearance. It is possible to remove the cause of the backlash and suppress the backlash of the spindle 3 to perform measurement with high accuracy. In addition, such a preload in a certain direction is different for each dial gauge 2 to be used, and therefore, it is necessary to appropriately set according to the dial gauge 2 to be used.
In addition, in the explanatory diagram modeled on the cantilever shown in FIG. 4, the bending state of the cantilever is enlarged for easy understanding in order to provide an understanding of the present invention. Such a large bending state does not occur, and a minute bending state at an invisible level is obtained.

  That is, in the configuration of the present invention, which is a countermeasure product in which countermeasures are taken against the conventional product shown in FIG. 14D, as described above, if the bending force increases more than necessary, the movement of the spindle 3 in the y-axis direction stops. Although the measurement becomes impossible, if the factor that generates the bending force more than necessary is removed in advance, that is, the length of the arm 7 that controls the bending force is set appropriately, so that the above-described clearance is obtained. Thus, the effect of improving the measurement accuracy can be obtained.

Next, an embodiment of a measuring jig in which the above-described separation distance M is specifically set will be described with reference to FIG.
When the separation distance M between the first measuring element 4 and the second measuring element 8 of the measuring jig 1 shown in FIG. 1 is a predetermined length or more (105 mm or more in this embodiment), the first measuring element 4 It was confirmed that the spindle 3 of the dial gauge 2 would not move in the direction of the arrow Y when a predetermined load was applied (this time is defined as the limit value of the separation distance M). That is, at this limit value, the spindle 3 is locked due to an increase in frictional resistance between the spindle 3 and the bearing portions 21 and 22. Therefore, it is necessary to determine a practical separation distance M within 0 to 105 mm (limit value). In the present embodiment, considering the safety factor, it was determined that weighting could be allowed if the separation distance M was within a range sufficiently smaller than the limit value, and the separation distance M was set to 29 mm.

Here, the case where the bending force (moment) according to the measurement pressure Pm is set to M × Pm = 29 [mm] × Pm [N] will be specifically described below.
In the case of using a dial gauge having a specification different from that of the dial gauge 2 of the present embodiment, it is necessary to appropriately obtain the limit value as described above, and a practical range of the separation distance M is derived therefrom in advance. It is necessary to set the separation distance M. That is, depending on the specifications of the dial gauge, for example, the clearance between the outer peripheral portion of the spindle 3 and the inner walls of the bearing portions 21 and 22 is different, so that the optimum separation distance M cannot be determined in general.

  In the graph shown in FIG. 5, the horizontal axis represents the load position M [mm], the vertical axis represents the expected bearing portion reaction force F1 [N], and the load position M and the expected bearing portion reaction force F1 [N] with respect to the load position. Is shown. For example, the plot e8 shows a state where the value of the separation distance M is 105 mm, and the bearing portion reaction force F1 is about 20N. As shown in FIG. 5, the bearing portion reaction force F <b> 1 suddenly increases when the value of the separation distance M exceeds about 90 mm, and the frictional resistance between the outer periphery of the spindle 3 and the inner walls of the bearing portions 21 and 22. It can be fully expected that the spindle 3 will be locked and locked.

Therefore, by ensuring a sufficient safety margin and setting the separation distance M to 29 mm (sufficiently smaller than 105 mm), excess e3 of the bearing 21 and e4 of the bearing 22 shown in FIG. While preventing the load, the clearance can be set to a state such as e5 of the bearing portion 21 and e6 of the bearing portion 22 shown in FIG.
In addition, since the measurement pressure Pm is a minute load, the moment due to the weight of the arm 7 and the first measuring element 4 (referred to as the self-weight moment) becomes a level that cannot be ignored. It is necessary to consider in advance.

Further, when the self-weight moment is large to some extent, it is possible to allow a measured pressure Pm that is equal to or less than the self-weight. That is, if the end portion of the arm 7 is bent slightly downward due to its own weight moment, the measured pressure is up to a reaction force that is equal to its own weight moment (up to a reaction force at a level that eliminates the bent state). Pm can be tolerated.
It is also possible to add a predetermined balance weight (not shown) on the side opposite to the protruding side of the arm 7 so as to cancel the influence of the self-weight moment.

The measuring jig 1 configured in this manner is fixed to a commonly used support stand for fixing a dial gauge, and the first measuring element 4 provided at the other end of the arm 7 is a workpiece to be measured. 6, and the amount of displacement of the measurement part of the workpiece 6 can be measured by the dial gauge 2 via the arm 7. Here, when measuring the displacement amount of the workpiece 6, the first measuring element 4 receives the measurement pressure Pm, and the arm 7 is formed in a cantilever shape with respect to the spindle 3. It is possible to apply a preload in a certain direction as described with reference to FIG. As a result, the clearance is removed within an allowable range, and the displacement of the measurement part of the workpiece 6 can be measured with high accuracy while eliminating the backlash of the spindle 3.
The support stand when using the measuring jig 1 is not particularly limited, and a support stand having a clamp for holding a commercially available dial gauge can be used. It is also possible to configure the displacement measuring device by mounting and fixing on the table 20, and to perform the measurement.

Next, another embodiment of the displacement measuring jig according to the present invention will be described with reference to FIGS.
In the above-described embodiment, the configuration including the bearing portions 21 and 22 as means for inserting and supporting the spindle 3 in the axial direction has been described. However, the structure of the bearing portion is not particularly limited. Therefore, a configuration of a displacement measuring jig provided with a bearing portion different from the above-described embodiment will be described as another embodiment.

As shown in FIGS. 6 and 7, a dial gauge 1A provided with a substantially cylindrical stem bush 40 is shown in FIG. 1 of Japanese Patent Laid-Open No. 2001-264003. Even if it clamps with a support clamp etc. and a clamping force is given, it has the structure where the bad influence by the clamping force is not given to the front-end | tip part of the stem bush 40. However, even with such a structure, when 5A-1 and 5A-2 shown in FIG. 7 are strongly clamped, the clearance of the clamped portion disappears, and the inner wall of the stem 10 and the outer peripheral portion of the spindle 3 come into contact with each other. Frictional resistance may increase.
In the present invention, the clearance is not maintained as described above, but as described above, the measurement accuracy is improved by intentionally removing the clearance, which is compared with the dial gauge 1A. Apply. That is, also in the dial gauge 1A, a slight clearance is provided between the outer peripheral portion of the spindle 3 and the inner wall of the stem bush 40 at the tip end portion of the stem bush 40, and this portion is used as a bearing portion in the above-described embodiment. 21 can be regarded as the same as e3 and e5 (see FIG. 4). That is, the present invention can be applied by regarding the stem bush 40 fixed to the inner wall of the stem 10 of the dial gauge 1A as the same as the bearing 21 of the measurement jig 1 described above. Therefore, in order to apply the present invention to the dial gauge 1A, one end of an arm is connected and supported to the middle part of the spindle 3 of the dial gauge 1A, and the arm is formed in a cantilever shape from the spindle 3. The measuring jig is configured so that the axis of the spindle 3 and the axis of the first measuring element provided at the other end of the arm are separated by a predetermined dimension M. Further, the separation distance M corresponding to the dial gauge 1A is determined so that an appropriate bending force can be obtained according to the setting method of the separation distance M described above.

Thus, in the dial gauge 1A having a cantilevered arm, when measuring the workpiece 6, the first measuring element is brought into contact with the measurement site of the workpiece 6, and the displacement amount of the first measuring element is determined by the arm. The dimension of the workpiece 6 can be measured by transmitting the displacement as the movement displacement amount in the axial direction of the spindle 3.
Here, as described above, the measurement pressure Pm is applied to the end portion of the arm. As in the above-described embodiment, the clearance is removed in a specific direction by using the bending force of the arm by the measurement pressure Pm. Thus, the measurement accuracy can be improved by reducing the backlash of the spindle.

  In addition, when the stem 10 and the spindle 3 are long as shown in FIG. 6, the influence of the increase in frictional resistance due to the bending of the spindle 3 due to the bending force is alleviated, so that the separation distance M contributing to the bending force can be set large. When the arm is connected to the spindle 3 by screw connection or the like, it is assumed that bending force is applied to the connecting portion, and deformation and slide resistance increase. Assuming such a case, the dial gauge 1A can be configured to increase the clearance in advance.

  In this way, the spindle 3 is movable in the axial direction, and the dial gauge 2 for measuring the displacement of the spindle 3, the arm 7 formed in a cantilever shape from the spindle 3, and the spindle 3. Since the measuring jig 1 is provided with the first measuring element 4 provided at the end of the arm 7 at a predetermined distance from the arm 7 and abutting against the workpiece 6, it is brought into contact with a conventional dial gauge. Therefore, it is possible to accurately measure the dimension of a member having a narrow or deep opening which is difficult to perform. Further, by utilizing the bending force of the arm generated at the time of measurement, the clearance can be removed in a specific direction, and the backlash of the spindle can be reduced to improve the measurement accuracy.

  Next, a displacement measuring device 30 that performs measurement by placing and fixing the measuring jig 1 described above will be described with reference to FIGS. 8, 9, and 10. FIG.

  As shown in FIG. 9, the displacement measuring device 30 is mainly composed of the measurement jig 1 and the base 20 described above.

  The base 20 is movable in a direction in which the work table 6 is fixed to the work 6, the mounting table 26 on which the measuring jig 1 is mounted and fixed, and the mounting table 26 close to and away from the work 6. The above-described mounting table 26 is configured so as to slide the mounting table 26 toward the workpiece 6 to guide the first measuring probe 4 to the measurement site of the workpiece 6 and the mounting table 26 in contact with the mounting table 26. And a micrometer 27 which is a position measuring means for measuring the position of the first measuring element 4 in the sliding direction.

  As shown in FIG. 8, the probe guide means 23 includes a plate-like slide base 24 in which rail grooves 25 and 25 (two in this embodiment) are provided in the longitudinal direction of the upper surface, and the measurement jig 1. It is comprised from the mounting base 26 to mount and fix.

  As shown in FIG. 8, the mounting table 26 is a plate-shaped table for mounting and fixing the measuring jig 1, and convex portions provided on the lower surface of the mounting table 26 are engaged with the rail grooves 25 and 25. It is slidably attached along the rail groove 25. Further, it is possible to accurately position in the slide direction by moving the mounting table 26 with one end of the spindle 27a of the micrometer 27 being brought into contact with one end of the mounting table 26. Further, the mounting table 26 is provided with a measuring jig 1 upright via a fixing jig 31 shown in FIG. 9, and the arm 7 of the measuring jig 1 is measured so that it is parallel to the sliding direction. The tool 1 can be fixedly supported. Further, the fixing jig 31 adjusts the position of the measuring jig 1 fixed and supported in the vertical direction (axial direction of the spindle 3), that is, adjusts the position of the first measuring element 4 in the vertical direction to obtain a desired measurement position. It is possible to fix with.

The micrometer 27 is fixed to the outer wall of the wall portion 24a that forms one end of the slide base 24, and the spindle 27a of the micrometer 27 is inserted through the wall portion 24a and can advance and retreat in parallel with the rail groove 25. It has become.
In addition, the micrometer 27 can rotate the thimble 28 or the ratchet 29 that is the operation portion of the micrometer 27 to move the spindle 27 a in the axial direction, and the tip of the spindle 27 a can be connected to the mounting table 26. The mounting table 26 can be slid and driven to a predetermined position by being brought into contact with one end.

  The work fixing means 32 is means for fixing a columnar work fixed to the upper surface of the slide table 24 on the other end side. The work fixing means 32 faces the measuring jig 1 fixedly supported on the mounting table 26. The cylindrical workpiece 6 can be fixedly supported on the side portion 32. Further, the shape of the workpiece 6 fixed to the workpiece fixing means 32 is not limited to the cylindrical workpiece 6 as shown in FIGS. 11 and 12, and the workpiece 6 having a recess, a through-hole or the like is fixedly supported. Is possible.

  In constructing the displacement measuring device 30, the error that occurs is determined by the entire measurement system including the measurement jig 1 and the base 20, so that the workpiece 6 is fixed to the workpiece fixing means 32, or the first measuring element. It is necessary that each part has a small error such as a fixed state of the measuring jig 1 having 4.

  When the micrometer 27 is operated to extend the spindle 27a toward the mounting table 26 and the distance d1 between the end of the mounting table 26 and the tip of the spindle 27a becomes zero, the mounting table 26 is moved onto the slide table 24. Slide resistance generated when sliding is applied to the micrometer 27. Therefore, the sum of the resistance when determining the position of the mounting table 26 on the slide table 24 and the resistance when driving the first measuring element 4 of the measuring jig 1 while being in contact with the workpiece 6 is micro. It becomes resistance when the ratchet 29 of the meter 27 is rotated. For this reason, configuring the probe guide means 23 to move more smoothly so that the function of the ratchet 29 works is a condition that enables smooth measurement.

By constructing the displacement measuring device 30 in this way, the cylindrical workpiece 6 as shown in FIG. 11 or 12 is fixed to the side surface of the workpiece fixing means 32 fixed on the slide table 24, When the measurement jig 1 is mounted upright on the mounting table 26 via the fixing jig 31 and measurement is performed, the thimble 28 or the ratchet 29 of the micrometer 27 is rotated to move the spindle 27a to the interval d1 (FIG. Press until (see 8) becomes zero. Then, the mounting table 26 can be driven along the rail groove 25 by further extending the spindle 27a. Accordingly, it is possible to smoothly move the measuring jig 1 in the horizontal direction (in the direction of the arrow in FIG. 9) in an upright state, and the other end of the arm 7 is connected to the through hole of the work 6 as shown in FIG. The first measuring element 4 provided at the end of the arm 7 is brought into contact with the measurement site of the work 6 by inserting it into the inside of the work 6, for example, measuring the displacement amount such as measuring the inner diameter of the work 6 at a predetermined position. (Dimension measurement) can be performed.
Thus, in order to perform smoother measurement using the measurement jig 1 described above, the displacement measuring device 30 may be configured in combination with the base 20 on which the measurement jig 1 is placed and fixed. By doing so, the measurement of the optimal state according to the workpiece | work 6 shape is attained.

  That is, the measurement jig 1 described above, the workpiece fixing means 32 for fixing the workpiece 6, and the measurement jig 1 are mounted and fixed on the mounting table 26, and the mounting table 26 is slid to the workpiece 6 side. A measuring element guide means 23 for guiding the first measuring element 4 to the measurement site of the work 6 and the work table 6 are driven in contact with the mounting table 26 described above, and the position of the first measuring element 4 in the sliding direction is determined. By configuring the displacement measuring device 30 including the micrometer 27 to measure, the posture state of the measuring jig 1 is maintained so as not to cause an error when measuring a member having a narrow opening. The first measuring element 4 can be easily brought into contact with the target measurement position. That is, as in the NG example shown in FIG. 14C, the first measuring element 4 can be set at the target measurement position and the accurate measurement can be performed without tilting the dial gauge 2.

  The present invention can also be applied to an existing dial gauge having a spindle bearing (spindle sliding means) in a stem or a housing. That is, by determining the separation distance M unique to the dial gauge based on the above-described setting method of the separation distance M, and performing a process of adding an arm provided with a measuring element to the spindle so as to be an allowable separation distance M. However, it is possible to obtain the effect of the present invention.

The side view which shows the whole structure of the displacement measuring jig concerning one Embodiment of this invention. Similarly perspective view. Similarly, it is a partially broken sectional view, (a) is a partially broken front view (b) is a partially broken side view. Explanatory drawing which shows the state of the spindle which the bending force produced. The figure which shows the relationship of the anticipated bearing part reaction force with respect to a load position. Sectional drawing which shows the principal part of the dial gauge which concerns on another Example. Similarly sectional drawing. The perspective view which shows the base which concerns on embodiment. The perspective view which shows the displacement measuring device which concerns on embodiment. Same perspective view It is a figure which shows a workpiece | work, (a) is a perspective view, (b) is AA arrow sectional drawing in (a). It is a figure which shows a workpiece | work, (a) is a perspective view, (b) is AA arrow sectional drawing in (a). It is explanatory drawing which shows the measurement state by the conventional dial gauge, (a) is a side view (b), and is a front view. The figure which shows the test indicator and dial gauge which are the conventional products.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Displacement measuring jig 2 Dial gauge 3 Spindle 4 First measuring element 6 Work piece 7 Arm 23 Measuring element guide means 26 Mounting table 27 Micrometer 30 Displacement measuring device 32 Work fixing means

Claims (3)

A displacement amount measuring means having a spindle movable in the axial direction and measuring a displacement amount of the spindle;
An arm that is cantilevered by the spindle and extends in a direction perpendicular to the axial direction of the spindle;
A displacement amount measuring jig, comprising: a measuring element provided at a position spaced apart from a spindle of the arm by a predetermined dimension and in contact with an object to be measured.   The displacement amount measuring jig according to claim 1, wherein the displacement amount measuring means is a dial gauge. The displacement amount measuring jig according to claim 1 or 2,
Fixing means for fixing the object to be measured;
A mounting table on which the displacement measuring jig is mounted and fixed;
A measuring instrument guide configured to move the mounting table in a direction in which the mounting table is moved toward and away from the object to be measured, and to guide the measuring element to a measurement site of the measuring object by sliding the mounting table to the measuring object side. Means,
A displacement amount measuring apparatus comprising: a position measuring unit that contacts the mounting table and drives the mounting table toward the object to be measured, and measures a position of the measuring element in a sliding direction.

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