JPH0489502A - Measuring device of precision of seat surface for connection of fluid piping - Google Patents

Abstract

PURPOSE:To measure the eccentricity of a conical seat surface to a round recession by a method wherein the state of advance or retreat of an internal rotary member in relation to an external tubular member is detected in such a manner as to correspond to the phase of rotation thereof while a curved-surface-shaped projecting part of that member is brought into sliding contact with the conical seat surface. CONSTITUTION:An external tubular member 11 is screwed and fixed inside a recession 3, and an internal rotary member 12 is rotated while the projecting surface 13a of a curved-surface-shaped projecting part 13 of the internal rotary member 12 is made to slide smoothly on a conical seat surface 4. A scale 16 and a dial gage 15 being used, on the occasion, the state of advance or retreat of the projecting surface 13a in relation to the conical seat surface 4 is measured in such a manner as to correspond to the phase of rotation of the place on the conical seat surface 4 in which the projecting surface 13a is in contact with the seat surface, and from this relation of the phase of rotation with the state of advance or retreat, it can be known how the axial line of the conical seat surface 4 is eccentric to the axial line of the internal rotary member 12 and the external tubular member 11, that is, the axial line of the round recession 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is for measuring the accuracy of a sheet surface for connecting fluid piping to form a flow path for liquid or gas, and to connect fluid piping in a liquid-tight or air-tight manner. Regarding equipment.

[Prior Art] For flow paths for liquids such as fuel and oil, or gases such as air, there are structures in which fluid piping (pipes) are buried inside connected members to connect them in a liquid-tight or air-tight manner. be.

For example, FIG. 6 is a cross-sectional view showing a connection part of fluid piping provided in an automobile. As shown in FIG. 6, a flow path 2 is formed in the connected member 1, and the open end of this flow path A circular recess 3 is formed in the recess 3 , and a conical sheet surface 4 is formed at the step between the recess 3 and the flow path 2 . Conical sheet surface 4
is a conical outer peripheral surface whose diameter decreases toward the open end of the flow path 2. Note that a female threaded portion 3a is provided on the inner peripheral surface of the recessed portion 3.

A fluid pipe 6 is connected to such a circular recess 3, and this fluid pipe 6 has a conical joint surface 6a having approximately the same shape as the conical sheet surface 4 at its tip, and the conical sheet The fluid pipe 6 is connected to the connected member 1 by aligning the conical joint surface 6a with the surface 4 and bringing it into close contact.

For this reason, an annular pressing surface 5a that aligns with the conical sheet surface 4 is provided on the outer periphery of the fluid piping 6 at the tip thereof.
A hole bolt 5 that can be screwed into the female threaded portion 3a is installed, and the hole bolt 5 firmly connects the conical joint surface 6a to the conical sheet surface 4. That is, by tightening the hole bolt 5 into the recess 3, the annular pressing surface 5a of the hole bolt 5 is pressed against the conical joint surface 6a of the fluid pipe 6.
is pressed against the conical sheet surface 4, and this pressing force ensures close contact between the conical joint surface 6a and the conical sheet surface 4.

By the way, in such a fluid piping connection structure, in order to ensure close contact between the conical joint surface 6a and the conical sheet surface 4, when the hole bolt 5 is screwed into the female threaded portion 3a,
The annular pressing surface 5a needs to be properly aligned with the conical seat surface 4.

Therefore, the annular pressing surface 5a and the conical sheet surface 4 must be formed with high precision.

Therefore, we would like to measure the accuracy of these aspects and perform product management. The precision of this surface includes, for example, the eccentricity precision of how far the respective axes are deviated from each other, and the surface inclination precision of whether the conical surface has a predetermined inclination.

However, since the annular pressing surface 5a is provided protrudingly at the tip of the drilled bolt 5, it is easy to measure its accuracy, but the conical sheet surface 4 is formed deep inside the circular recess 3. Furthermore, since the inner diameter of the circular recess 3 is generally small (for example, on the order of several square meters), it is extremely difficult to measure the accuracy of the conical seat surface 4.

Since it is not possible to measure the surface shape of such a deep and detailed part using normal measuring instruments, the conical sheet surface 4 is generally placed on the axis of the circular recess 3 with high accuracy and shape. It is conceivable to cut it without deforming it to obtain an accurate cross section (see FIG. 6), and then measure this cross section.

[Problems to be Solved by the Invention] However, it is extremely difficult to obtain an accurate cross section of the conical sheet surface 4 by breaking the conical sheet surface 4 as described above. Even if you get a cross section,
This measurement sample cannot be used again, so although it is helpful for product control, it is not sufficient for desired product control.

Therefore, it would be desirable to be able to reliably measure the accuracy of the conical sheet surface 4 without destroying the connected member 1.

The present invention was devised in view of such problems, and
It is an object of the present invention to provide a sheet surface accuracy measuring device for fluid piping connection that can reliably measure the accuracy of a sheet surface without destroying members.

[Means for Solving the Problems] Therefore, the fluid piping connection sheet surface accuracy measuring device according to the first aspect of the present invention includes a conical sheet formed in a circular recess into which a fluid piping can be inserted and connected. A sheet surface accuracy measuring device for measuring surface accuracy includes an outer cylindrical member that can be aligned with the inner circumferential surface of the circular recess, and an inner cylindrical member that is rotatable with respect to the outer cylindrical member. and an internal rotating member installed so as to be movable in the axial direction, and a curved protrusion that can come into contact with the conical seat surface is formed on the internal rotating member, and the curved protrusion is brought into contact with the conical seat surface. Detecting means for detecting forward and backward movement during rotation is provided which can detect the forward and backward movement of the internal rotating member that may occur when the internal rotating member is rotated while slidingly contacting the internal rotating member in correspondence with its rotational phase. It is characterized in that the eccentricity of the conical seat surface with respect to the circular recess can be measured from the relationship between the rotational phase detected by the means and the forward/backward movement state.

Further, the fluid piping connection sheet surface accuracy measuring device according to the second aspect of the present invention is a sheet surface accuracy measuring device for measuring the accuracy of a conical sheet surface formed in a circular recess into which a fluid piping can be inserted and connected. An accuracy measuring device, comprising an external cylindrical member that can be inserted into the inner peripheral surface of the circular recess, and an internal reciprocating member installed inside the external cylindrical member so as to be movable in the axial direction,
An outer protrusion capable of contacting the conical seat surface is formed at the distal end of the external cylindrical member, and an outer protrusion capable of contacting the conical seat surface is formed at the distal end of the internal reciprocating member. An axial deviation detection means capable of detecting an axial deviation of both projections when each of these projections comes into contact with the conical sheet surface is provided, and the axial deviation detection means detects the deviation in the axial direction of both projections. It is characterized in that the inclination of the conical sheet surface can be detected based on the axial deviation.

[Function] In the fluid piping connection sheet surface accuracy measuring device according to the first aspect of the present invention, the external cylindrical member is aligned with the inner circumferential surface of the circular recess, and the device is attached to the circular recess to measure the curved surface. The internal rotating member is rotated within the external cylindrical member while the protrusion is brought into sliding contact with the conical sheet surface. At this time, by means for detecting forward and backward conditions during rotation.

The movement of the internal rotating member relative to the external cylindrical member is detected in correspondence with its rotational phase, and the eccentricity of the conical seat surface relative to the circular recess is measured from the relationship between the detected rotational phase and the movement.

Further, in the sheet surface accuracy measuring device for fluid piping connection according to the second aspect of the present invention, an external cylindrical member is inserted into the inner circumferential surface of the circular recess, and the outer protrusion at the tip of the external cylindrical member is brought into contact with the conical seat surface, and the internal reciprocating member is advanced within the outer cylindrical member to bring the inner protrusion at the tip of the internal reciprocating member into contact with the conical seat surface together with the outer protrusion. At this time, the inclination of the conical sheet surface is detected based on the axial deviation detected by the axial deviation detection means.

[Examples] Examples of the present invention will be described below with reference to the drawings.
1 to 3 show a sheet surface accuracy measuring device for fluid piping connection as a first embodiment of the present invention, FIG. 1 is a partially cutaway side view, and FIG. 2(a) is a side view of the internal rotating member, FIG. 2(b) is a front view of the tip of the internal rotating member, FIG. 3 is a side view of the main part showing a modified example of the internal rotating member, and FIGS. 4 and 5 are This shows a sheet surface accuracy measuring device for fluid piping connection as a second embodiment of the present invention, and FIG.
Figure (b) is a partially broken plan view showing the connection between the external cylindrical member and the axial deviation detection means [However, the fractured surface is along the IVb-mVb arrow line in Figure 4(a). FIG. 5 is a cutaway side view of the main parts showing the state of contact between the mask and the jig.

The sheet surface accuracy measuring devices of these embodiments are all devices for measuring the accuracy of the conical sheet surface 4 provided on the connected member 1 as shown in FIG. Since the detailed explanation regarding 4 is as described above, it will be omitted here.

The device of the first embodiment is a device corresponding to the first claim of the present invention, and measures the eccentricity of the conical sheet surface 4, and the device of the second embodiment is a device according to the first aspect of the present invention. This apparatus corresponds to the second claim, and measures the inclination of the conical surface of the conical sheet surface 4.

First, to explain the first embodiment, as shown in FIG.
An internal rotating member (core) 12 installed inside the dial cage 15 and a rotational phase detection means for detecting the advancing and retreating state of the internal rotating member 12 in correspondence with its rotational phase. It is configured with a scale 16.

The external cylindrical member 11 has a male thread lla formed on its outer circumferential surface on the front end side, which can be screwed into the female thread 3a formed on the inner circumferential surface of the recess 3. A knob portion 11b is formed on the outer cylindrical member 11 to adjust the screwing of the male thread lla to the female thread portion 3a. By rotating the external cylindrical member ]l through this knob 11b, the external cylindrical member 11 can be fixed inside the recess 3 or removed.

The internal rotating member 12 is installed so as to penetrate through the inside of the external cylindrical member 11, and can freely rotate inside the external cylindrical member 11 and can also freely move forward and backward in the axial direction. . However, the inner circumferential surface of the outer cylindrical member 11 and the outer circumferential surface of the inner rotating member 12 are formed with high precision so that there is no looseness, and the outer cylindrical member 11 and the inner rotating member 12 are mutually the same. The other parts are also formed with a predetermined precision so as to form the axial center line.

Further, as shown in FIGS. 2(a) and 2(b), this internal rotating member 12 has a sliding surface 12a formed on the outer periphery of the intermediate portion to be in sliding contact with the inner peripheral surface of the external cylindrical member 11. A head 12b with an enlarged diameter is formed at the tip, and a curved protrusion 13 that can come into contact with the conical seat surface 4 is formed on the head 12b.

This curved protrusion 13 partially protrudes from the distal end surface of the head 12b, and has a smooth surface at approximately one point with the conical seat surface 4 on the inner side of the distal end, which faces the conical seat surface 4. A smooth protruding surface 13a is formed so as to be in sliding contact with the surface.

Further, a knob 12c for rotating the internal rotating member 12 with respect to the external cylindrical member 11 is formed on the outer circumferential surface of the rear end of the internal rotating member 12.

Further, the relative rotational phase of the internal rotating member 12 with respect to the external cylindrical member 11 is set at the boundary between the external cylindrical member 11 and the internal rotating member 12 (in this case, the boundary between the knob 11b and the knob 12C). A detectable rotational phase detection graduation 16 is provided. The scale 16 includes a reference point 16a provided at the end of the knob 11b and a scale (equally spaced scale) 16b adjacent to the reference point 16a provided at the end of the knob 12c. Note that the reference point 16a may be provided on the internal rotating member 12, and the scale 16b may be provided on the external cylindrical member 11. In addition, the relationship between the scale 16b or reference point 16a provided on the internal rotating member 12↓ and the protrusion surface 13a can be grasped, and at which position (rotational phase) on the conical seat surface 4 does the protrusion surface 13a come into contact with the scale 16? Make sure you know what you are doing.

Then, the dial cage 15 is displaced relative to the external cylindrical member 11 so that the detection pin 15a is oriented parallel to the axis of the internal rotating member 1'2 and abuts against the rear end surface of the internal rotating member 12. It is fixed so that it does not occur.

In addition, in the figure, code 2 is a flow path, and 15b is a dial cage 1.
5, 15c is the scale of the dial cage 15.

The fluid piping connection sheet surface accuracy measuring device according to the first embodiment of the present invention is configured as described above, so that the external cylindrical member 11 is screwed and fixed inside the recess 3, and the internal rotating member 12 While smoothly sliding the protrusion surface 13a of the curved protrusion 13 on the conical seat surface 4,
Rotate 2.

At this time, while using the scale 16 and dial gauge 15, determine the rotational phase of the internal rotating member 12, that is.

Corresponding to the rotational phase of the contact point of the protrusion surface 13a on the conical seat surface 4, the movement state of the internal rotating member 12 relative to the external cylindrical member 11, that is, the protrusion surface 13a relative to the conical seat surface 4 is determined. Measure progress and retreat.

From the relationship between the rotational phase and the advance/retreat situation,
It can be seen how the axial center line of the conical seat surface 4 deviates from the axial center line of the internal rotating member 12 and the external cylindrical member 11, that is, the axial center line of the circular recess 3.

In this way, the eccentricity of the conical sheet surface 4 can be measured without damaging the conical sheet surface 4 and the member (connected member) l that forms it.

Note that the curved protrusion provided on the internal rotating member 12 may be as shown in FIG. 3 (see reference numeral 14). In other words, the protrusion surface (see reference numeral 14a) is made into a spherical shape that largely protrudes from the inside of the tip of the curved protrusion 14 in the direction of the conical seat surface 4, and the contact point with the conical seat surface 4 on the protrusion surface 14a is It is also conceivable to create a device that does not allow the disc to shift. In this case, in addition to integrally forming the protrusion surface 14a on the protrusion 14, a separate protrusion surface 14a may be fixed to the protrusion 14.

Moreover, if the contact point with the conical sheet surface 4 is protruded to some extent, the protruding surface 1 having this contact point
The protrusion 14 supporting the head 4a may be annular rather than partially protruding from the distal end surface of the head 12b. This may be easier to process.

Furthermore, the protruding surface is not limited to this, and may have any other shape as long as it has a large protruding point of contact with the conical sheet surface 4 and has a certain degree of durability.

Next, the second embodiment will be described. As shown in FIG. 4(a), this fluid piping connection sheet surface accuracy measurement device w
Reference numeral 20 denotes an external cylindrical member (main body) 21, an internal reciprocating member (core) 22 provided inside the external cylindrical member 21, and a shaft capable of detecting the axial displacement of the internal rotating member 22. It is configured to include a dial cage 25 as a directional displacement detection means.

The external cylindrical member 21 has a thin cylindrical portion 21 at its tip.
a is formed, and an outer protrusion 23 that can come into contact with the conical sheet surface 4 is formed at the tip of this cylindrical portion 21a.

As shown in FIG.
This is an annular protrusion formed by the inner peripheral corner of the tip of 1a.

Further, the outer circumferential surface of the cylindrical portion 21a is the inner circumferential surface (
The diameter is set so that it can be inserted into the IIl threaded portion 3a). Furthermore, a knob 21b is formed on the outer circumferential surface of the rear end of the external cylindrical member 21, which can be grasped when inserting the cylindrical portion 21a into the circular recess 3.

The internal reciprocating member 22 is installed inside the external cylindrical member 21 so as to be movable in the axial direction, and a thin cylindrical portion 22a is formed at the tip of the cylindrical portion 22a. , an inner protrusion 24 that can come into contact with the conical seat surface 4 is formed. As shown in FIG. 5, the inner protrusion 24 is an annular protrusion formed by the inner peripheral corner of the tip of the cylindrical portion 22a.

Further, a connecting member 26 is fitted and fixed to the rear end of the external cylindrical member 21, and a shaft 25b on the main body side around the detection pin 25a of the dial cage 25 is inserted into the inside of this connecting member 26. A hole 2-60 that can be clamped and connected is formed in the rear end of the connecting member 26 as shown in FIG. 4(a).
) and (b), tightening sections 26a and 26b are provided at appropriate intervals so as to reduce the diameter of the hole 26c, and the tightening sections 26a and 26b are connected to an adjusting bolt 27.
By tightening the hole 26c, the diameter of the hole 26c is reduced and the shaft 2
5b is fixed in the hole 26c. In FIG. 4(b), reference numeral 27a is a threaded portion that is screwed into the female threaded portion of the tightening portion 26b, and 27b is a knob portion.

The dial cage 25 is thus integrally coupled to the rear end portion of the external cylindrical member 21. At this time, the dial cage 25
The detection pin 25 a of No. 5 comes into contact with the rear end surface of the internal reciprocating member 22 and can detect the axial movement of the internal retracting member 22 with respect to the external cylindrical member 21 . At the time of this contact, the protrusions 23 and 24 are set at approximately the same position in the axial direction, or the protrusions 24 are set slightly backward than the protrusions 24.

However, the outer cylindrical member 21 and the inner rotating member 22 are arranged so that the inner circumferential surface of the outer cylindrical member 21 and the outer circumferential surface of the inner rotating member 22 do not wobble, and the protrusions 23 and 24 are aligned with each other on the same axis. It is formed with a predetermined precision so as to form a core wire.

In addition, in this apparatus, as shown in FIG. 5, the master jig 28 of the conical sheet surface 4 is simplified. This mask-jig 28 is provided with a conical surface 28a corresponding to the conical sheet surface 4 at its tip, and is provided in appropriate types within the necessary angle range (for example, provided at every 0°1 degree or 0.5 degree (an appropriate number for each area).

In addition, in the figure, 25c is a scale of the dial cage 25.

The fluid piping connection sheet surface accuracy measuring device according to the second embodiment of the present invention is configured as described above, so that the cylindrical portion 21a of the external cylindrical member 21 is inserted into the circular recess 3, and each The entire projections 23 and 24 are brought into contact with the conical seat surface 4 in an annular manner at the same time, and the scale of the dial cage 25 at this time is read.

Next, the cylindrical portion 2 of the external cylindrical member 21 is attached to the master jig 28.
1a and the cylindrical portion 22a of the internal reciprocating member 22, the entire protrusion 23.24 is brought into contact with the conical surface 28a at the same time, and while reading the scale of the dial cage 25 at this time, The mask-jig 28 corresponding to the value of the scale of the dial cage 25 detected in the above is selected, and the inclination angle of this mask-jig 28 can be made the inclination angle of the conical sheet surface 4.

In addition, when the projections 23 and 24 are brought into contact with the conical seat surface 4 or the conical surface 28a, the fineness of the conical surface and the axes of the external cylindrical member 21 and the internal reciprocating member 22 are made to coincide with each other. Take measurements.

In this way, the inclination of the conical sheet surface 4 can be measured without damaging the conical sheet surface 4 and the member (connected member) 1 forming it.

In the above-mentioned embodiment, the projections 23 and 24 are annular and are brought into contact with the conical seat surface 4 or the conical surface 28a for measurement, but the projections 23 and 24 are not annular and are measured.
It is also conceivable that the partially protruding part may be brought into contact with the conical sheet surface 4 or the conical surface 28a by point contact, for example, and in this case, the rotation of the outer protrusion and the inner protrusion that make point contact may be It is necessary to arrange them in the same phase in the direction so that they are in contact with each other.

Also, the protrusions 23 and 24 when installing the dial gauge 25
It is also possible to determine the inclination directly from the reading scale of the dial gauge 25 without using the mask-jig 28 by appropriately performing the initial setting. In this case, the projection 23
．． In addition to calculating the inclination geometrically from the axial deviation of the dial gauge 24 and the diameter of the protrusion, a map of the correspondence of the inclination value of the conical surface to the reading scale value of the dial gauge 25 is created in advance, and this map is used. Ask them to refer to it and find the slope.

Each of the above-mentioned embodiments shows an example of manual measurement, but the configuration of these devices can be calculated using a computer by rotating with a stepper motor, etc., or detecting the axial deviation electrically. It is also conceivable that automatic measurements will be developed to perform such things.

[Effects of the Invention] As described in detail above, according to the fluid piping connection sheet surface accuracy measuring device of the first aspect of the present invention, the cone formed in the circular recess into which the fluid piping can be inserted and connected. A sheet surface measuring device for measuring the accuracy of a shaped sheet surface, comprising: an outer cylindrical member that can be aligned with the inner circumferential surface of the circular recess; and an internal rotating member installed to be movable back and forth in the axial direction, a curved protrusion that can abut the conical seat surface is formed on the internal rotating member, and the curved protrusion is connected to the conical seat surface. A rotating advancing/retracting state detecting means capable of detecting the advancing/retreating state of the internal rotating member that may occur when the internal rotating member is rotated while slidingly contacting the seat surface in correspondence with the rotational phase is provided. The configuration is such that the eccentricity of the conical seat surface with respect to the circular concave portion can be measured from the relationship between the rotational phase detected by the forward/backward state detection means and the forward/backward state, and the conical seat surface and the member forming the conical seat surface can be measured. It is now possible to measure the eccentricity of the conical sheet surface without damaging it, which has the effect of greatly contributing to product management of fluid piping connecting members.

Also, the second aspect of the present invention! ! ! According to the claimed sheet surface accuracy measuring device for fluid piping connection, the sheet surface measuring device is for measuring the accuracy of a conical sheet surface formed in a circular recess into which a fluid piping can be inserted and connected. , an outer cylindrical member that can be aligned with the inner circumferential surface of the circular recess, and an inner reciprocating member that is installed inside the outer cylindrical member so as to be movable in the axial direction; An outer protrusion capable of contacting the conical seat surface is formed, and an outer protrusion capable of contacting the conical seat surface is formed at the distal end of the internal reciprocating member. An axial deviation detection means capable of detecting an axial deviation of both protrusions when in contact with the conical sheet surface is provided, and the conical By setting the configuration so that the inclination of the seat surface can be detected, it becomes possible to measure the inclination of the conical seat surface without damaging the conical seat surface and the members forming it, and the inclination of the fluid piping connection member can be measured. It has the effect of significantly contributing to product management.

[Brief explanation of the drawing]

1 to 3 show a sheet surface accuracy measuring device for fluid piping connection as a first embodiment of the present invention, FIG. 1 is a partially cutaway side view, and FIG. 2(a) 2(b) is a front view of the tip of the internal rotating member, FIG. 3 is a side view of the main part showing a modification of the internal rotating member, and FIG. 4.5 is a side view of the internal rotating member. This shows a sheet surface accuracy measuring device for fluid piping connection as a second embodiment of the present invention, and FIG.
Figure (b) is a partially broken plan view showing the connection between the external cylindrical member and the axial deviation detection means [However, the fractured surface is along the IVb-IVb arrow line in Figure 4(a). FIG. 5, which is a cross-sectional view, is a cutaway side view of the main part showing the state of contact with the master jig, and FIG. 6 is a cross-sectional view showing the conventional sheet surface for fluid piping connection. 1.-Connected member, 2-Flow path, 3.--Circular recess, 3a
- Female threaded part, 4 - Conical seat surface, 10.20 - Seat surface accuracy measuring device for fluid piping connection, 11 External cylindrical member (main body), 11a - Male thread, 1lb - Knob part, 12 - Internal rotating member ( core), 12a-sliding surface, 12b-head, 1
2c - knob, 13° 14 - curved protrusion, 13a, 1
4a-projection surface, 15.25-dial cage, 15a,
25a-detection pin, 15b, 25b-dial cage body, 15c, 25cm dial cage scale, 16a-
Reference point, 16b-scale, 16-rotational phase detection scale, 21
- External cylindrical member (main body), 21a, 22a - cylindrical part, 2
1b-knob portion, 22-internal rotating member C core), 23-outer protrusion, 24-inner protrusion, 26 connection member, 26a
, 26b - Tightening part, 26c - Hole, 27 - Adjustment bolt, 27a - Thread part, 27 b - Knob part, 28-7
Star jig, 28 a - conical surface.

Claims (2)

[Claims] (1) In a seat surface accuracy measuring device for measuring the accuracy of a conical seat surface formed in a circular recess into which a fluid piping can fit and be connected, an external cylindrical shape that can be aligned with the inner peripheral surface of the circular recess is provided. and an internal rotating member installed inside the external cylindrical member to be rotatable with respect to the external cylindrical member and movable in the axial direction, and the internal rotating member is provided with a rotatable member installed on the conical seat surface. A curved protrusion that can be brought into contact is formed, and the forward and backward movement of the internal rotary member that may occur when the internal rotary member is rotated while the curved protrusion is in sliding contact with the conical sheet surface is determined as its rotational phase. A rotational advance/retreat situation detecting means is provided which can be detected in a corresponding manner, and the eccentricity of the conical seat surface with respect to the circular recess can be measured from the relationship between the rotational phase detected by the rotational advance/retreat situation detecting means and the advance/retreat situation. A sheet surface accuracy measuring device for fluid piping connection, characterized in that it is set as follows. (2) In a seat surface accuracy measuring device for measuring the accuracy of a conical seat surface formed in a circular recess into which a fluid pipe can fit and connect, an external cylindrical shape that can be inserted into the inner peripheral surface of the circular recess. and an internal reciprocating member installed inside the external cylindrical member so as to be movable in the axial direction, and an outer protrusion that can come into contact with the conical sheet surface is formed at the tip of the external cylindrical member. At the same time, an outer protrusion that can come into contact with the conical seat surface is formed at the tip of the internal reciprocating member, and the axes of both protrusions when these protrusions contact the conical seat surface, respectively. An axial deviation detection means capable of detecting a deviation in the direction is provided, and the inclination of the conical sheet surface can be detected based on the axial deviation detected by the axial deviation detection means. A sheet surface accuracy measuring device for fluid piping connection, characterized by: