JP4378907B2 - Seal end face processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of machining a seal end face such as a pipe joint that allows a fluid tight connection by being butted together.
[0002]
[Prior art]
Conventionally, as a seal end face processing method, in JP-A-5-131361, using a burnishing tool having a plurality of burnishing rolls rotatably supported in a direction orthogonal to the axial direction on the front end face of a cylindrical frame, A method of burnishing the rounded convex portion on the valve seat surface is disclosed.
[0003]
On the other hand, the present inventors have proposed a pipe joint shown in the figure in JP-A-11-6585. This pipe joint includes a pair of tubular joint members (1) (2), an annular gasket (3) interposed between the butted end faces of both joint members (1) (2), and both joint members (1 ) (2) and a screw means for connecting, and each of the joint members (1) and (2) is provided with annular gasket pressing projections (7) and (8), respectively, ) (8) is located on the radially outer side of the inner periphery (1a) (2a) of the butt end face of the joint member (1) (2), and the cross section of each projection (7) (8) The contour shape is composed of an arc portion (7b) (8b) extending radially outward from the butt end face and a linear portion (7a) (8a) connected to the arc portion (7b) (8b), and the arc portion (7b) ( The center of 8b) is radially inward from the intersection of the arc portions (7b) (8b) and the straight portions (7a) (8a), and the straight portions (7a) (8a) are 30 in the axial direction. It is inclined by ~ 60 °.
[0004]
The inner flat surfaces (15) and (16) and the outer flat surfaces (17) and (18) are formed on both the inner and outer sides of the protrusions (7) and (8) at each butting end surface. The inner flat surfaces (15) and (16) are projected from the outer flat surfaces (17) and (18) toward the left and right gasket (3).
[0005]
Further, reference numerals (9) and (10) indicate an over-tightening preventing annular protrusion, and these over-tightening preventing annular protrusions (9), (10) are provided in a left-right gasket ( 3) Projected to the side, the retainer (5) is pressed from both sides when attempting to tighten further than proper tightening. Each over-tightening prevention annular projection (9) (10) protects the projection (7) (8) of each joint member (1) (2) before assembly, which has an important effect on the sealing performance. The protruding protrusions (7) and (8) are prevented from being damaged.
[0006]
Fig. (A) is an enlarged view of the state in which the nut (4) is tightened by hand. As shown in the figure, when the nut (4) is tightened, the protrusion (7) (8 ) First protrudes from the end face of the gasket (3) .At this time, the gap between the inner flat face (15) (16) of each joint member (1) (2) and the left and right end faces of the gasket (3) Each has an inner gap (G1), and between the outer flat surfaces (17) (18) of the joint members (1) (2) and the left and right end surfaces of the gasket (3), Also have large outer gaps (G2). Further, an even larger gap (G3) exists between the overtightening preventing annular projections (9), (10) and the retainer (5). That is, G1 <G2 <G3. When the nut (4) is further tightened with a spanner or the like from the state of being manually tightened, the gasket (3) is deformed and the inner gap (G1) becomes zero first. At this time, the outer gap (G2) is not zero. During proper tightening, the outer gap (G2) is also zero, and the inner flat surfaces (15) and (16) are in close contact with the inner edges of the left and right end surfaces of the gasket (3), as shown in FIG. Thus, the inner circumferences (1a) and (2a) of the joint members (1) and (2) and the inner circumference (3a) of the gasket (3) are substantially flush with each other. That is, there is no recess that becomes a liquid pool. Note that the gap (G3) between the overtightening preventing annular projections (9), (10) and the retainer (5) is not zero even at this time. If tightened further than this, the gap (G3) between the overtightening preventing annular projections (9), (10) and the retainer (5) becomes 0, the resistance to tightening becomes very large, and overtightening is not possible. Is prevented.
[0007]
Thus, when tightening is completed, a recess corresponding to the protrusion (7) (8) is formed on the end surface of the gasket (3), and the inner periphery (1a) (2a) of the butted end surface of each joint member (1) (2) And the inner periphery (3a) of the gasket (3) are substantially flush with each other.
[0008]
That is, this pipe joint does not obtain a sealing property only by the protrusions (7) and (8) biting into the gasket (3), but a flat surface that contributes to sealing at least one of the inside and outside of the base of the protrusion (3) ( 15) (16) (17) (18), and these flat surfaces (15) (16) (17) (18) are in close contact with the gasket (3), so that even better sealing performance is achieved. , Having the advantage of being able to obtain tightening characteristics and disassembly characteristics. Further, in this pipe joint, the first and second joint members (1) are formed by the linear portions (7a) and (8a) of the protrusions (7) and (8) being inclined by 30 to 60 ° with respect to the axial direction. The frictional force when moving the gasket (3) in the axial direction with respect to (2) is almost the same as that of the circular arc shape in which the cross section of the seal projection has no straight part, and the straight part extending in the axial direction There is also an advantage that the problem that the gasket (3) is difficult to separate from the joint members (1) and (2) does not occur at the time of disassembly due to the protrusions having the.
[0009]
[Problems to be solved by the invention]
The seal end face processing method described in the above-mentioned Japanese Patent Laid-Open No. 5-131361 is insufficient for application to the manufacture of a pipe joint that requires extremely high precision. In particular, the pipe joint shown in Japanese Patent Laid-Open No. 11-6585 Thus, in order to manufacture a pipe joint in which the seal-contributing flat surface of the joint member is in close contact with the gasket, a new seal end face processing method is required.
[0010]
In view of the above situation, an object of the present invention is to provide a seal end face processing method in which protrusions can exhibit desired seal characteristics.
[0011]
Another object of the present invention is to provide a method for processing a seal end face that is useful when manufacturing a pipe joint in which a flat surface that contributes to the seal of the joint member is in close contact with the gasket.
[0012]
[Means for Solving the Problems and Effects of the Invention]
The seal end face processing method according to the present invention is a method for processing a seal end face having an annular projection and a flat surface contributing to the seal on at least one of the inside and outside of the base of the projection. and Earl processing step of simultaneously machining a flat surface, it includes a burnishing step of simultaneously mirror finish and high hardness of the annular projection and the sealing contribution flat surface with a burnishing tool, the seal end face, and out of the base of the projections Both have flat surfaces that contribute to sealing, and the end face shape of the total type bite is such that the outer flat surface protrudes more than the inner flat surface, and the burnishing roll has a diameter of the inner and outer circumferential surfaces. Are made equal to each other.
[0013]
With the sealing end face machining method of this invention, and Earl process of processing the annular projection and the sealing contribution flat surface using the total mold byte, mirror finish and high hardness of the annular projection and the sealing contribution flat surface with a burnishing tool By performing the burnishing process, it is possible to process the seal end surface having a flat surface that contributes to the seal on at least one of the inside and the outside of the base portion of the protrusion, with fewer steps.
[0014]
It is preferable to perform deburring after performing the first rounding and burnishing, and further to perform the second rounding and burnishing. The seal end face has a high hardness and needs to have a mirror finish. By performing the rounding process and the burnishing process twice, a desired hardness and a more accurate mirror finish can be obtained.
[0015]
Further, the contour shape of the cross-section of each annular protrusion is composed of an arc portion extending radially outward from the abutting end surface and a linear portion connected to the arc portion, and the center of the arc portion is more than the intersection of the arc portion and the linear portion. It is inward in the radial direction, and the straight part is inclined 30 to 60 ° with respect to the axial direction, and the straight part is inclined 30 to 60 ° in the axial direction by using a grooving tool or a boring tool. In some cases, the R-cut process is performed after the burnishing process and the subsequent deburring process. Such a protrusion shape is useful for forming a pipe joint having a high level of all of sealing performance, tightening characteristics and disassembly characteristics, and the R-cut process for obtaining this protrusion shape is performed by a burnishing process and thereafter. By further performing the deburring step, a more preferable protrusion shape can be obtained while maintaining the hardness of the seal end face and the mirror finish.
[0016]
The seal end surface has a flat surface that contributes to sealing both inside and outside the base of the protrusion, and the end face shape of the total type bite may be such that the outer flat surface protrudes more than the inner flat surface. In this way, the inner flat surface of the seal end face is projected in the axial direction after the rounding process using the total type tool, and the inner flat surface having the larger contribution to the seal is burned during burnishing. It hits the burnishing tool, and the mirror finish and higher hardness are applied with higher accuracy.
[0017]
If earlier end annular projection having a tapered base portion continuous with the distal end portion with an arcuate cross section to process the sealing end surface formed at the edge of the fluid passage, the total mold bytes having a recess corresponding to the annular projection A round processing step that processes an annular projection using a burnishing tool and a burnishing processing step that uses a burnishing tool to mirror-finish and increase the hardness of the annular projection, and the height of the projection before burnishing is higher than the height after processing It is preferable that the taper angle of the protrusion before burnishing is smaller than the taper angle after processing.
[0018]
And Earl machining for machining a circular projection with a total mold bytes, performs a burnishing to mirror finish and high hardness of the annular projection with a burnishing tool, a high after processing the height of the burnishing previous projection If the taper angle of the protrusion before burnishing is smaller than the taper angle after processing, the seal end face can be processed so that the protrusion contributing to the seal can exhibit the desired sealing characteristics.
[0019]
The rounding process may be performed in two steps: rough machining using a total bite of ultra-fine cemented carbide material and finishing process using a total bit of TIN or TIAL coated ultrafine carbide material. . As a result, it is possible to extend the lifespan of the all-purpose tool and the burnishing roller, and to obtain a desired projection shape with high accuracy.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0021]
The seal end face processing method according to the first invention sequentially performs the following steps as shown in FIGS.
[0022]
1. A cylindrical material (21) in which a through hole (lower hole) (21a) serving as a fluid passage has been processed is prepared (FIG. 1A).
[0023]
2. The outer diameter end face (21b) is processed to be flat using an external cutting tool (22), a milling full back cermet, or a cemented carbide tip (FIG. 1 (b)).
[0024]
3. The counterbore (24) is processed using the end mill (23) (FIG. 1 (c)).
[0025]
4). Using an inner diameter tool (25) or an end mill, the fluid passage end inner diameter (26) having a diameter slightly larger than the diameter of the lower hole (21a) is processed (FIG. 1 (d)).
[0026]
5. Using the end face grooving tool (27), an annular groove (28) is formed on the outer peripheral edge of the bottom face of the counterbore (24) (FIG. 1 (e)).
[0027]
6). An annular protrusion (30) is formed on the bottom surface of the counterbore (24) by using an R-type cutting tool (29) made of ultra-fine particle carbide with a circular arc-shaped recess (29a) formed to form the protrusion (30). And flat surfaces (31) and (32) are formed on the inside and outside of the protrusion (30) (referred to as rounding) (FIG. 2 (a)).
[0028]
7). Using a burnishing tool (33) having a burnishing roller (34) made of plastic mold steel or tool steel system corresponding to the counterbore (24) bottom projection (30) and flat surfaces (31) (32) on both sides thereof Then, the protrusion (30) and the flat surfaces (31) and (32) on both sides of the protrusion (30) are burnished (FIG. 2B). The configuration of the burnishing tool (33) other than the shape of the burnishing roller (34) is a known configuration, for example, Superoll of Sugino Machine Co., Ltd. is known. As the material for the burnishing roller (34), in addition to the steel for plastic molds (SKD11 series), which has excellent durability, specularity and toughness, Sugino Machine standard material with excellent wear resistance (Tool steel type system) may be used. In any case, the roller is mirror-finished and requires a hardness of HRC 60 or higher.
[0029]
8). Deburring the inner diameter (26) of the fluid passage end using an inner diameter tool (25) or an end mill (FIG. 2 (c)).
[0030]
9. Using the end face grooving tool (27), the annular groove (28) on the bottom surface of the counterbore (24) is deburred (FIG. 2 (d)).
[0031]
10. Using the R-type cutting tool (29) made of ultrafine particle carbide with a circular arc-shaped recess (29a) for forming the protrusion (30), the protrusion (30) on the bottom face of the counterbore (24) and its both sides The flat surfaces (31) and (32) are processed. That is, 6. The same rounding process is performed to increase the hardness and stabilize the state of the end face (FIG. 2 (e)).
[0032]
11. Using a burnishing tool (33) made of steel for plastic molds having a burnishing roller (34) corresponding to a protrusion (30) on the bottom face of the counterbore (24) and flat surfaces (31) (32) on both sides thereof, the protrusion ( 30) and flat surfaces (31) and (32) on both sides of the protrusion (30) are burnished. That is, The same processing is performed to increase the hardness and stabilize the state of the end face (FIG. 3A).
[0033]
12 Deburring the inner diameter (26) of the fluid passage end using an inner diameter tool (25) or an end mill (FIG. 3B). That is, 8. The same process is performed to remove the radial bulge caused by burnishing.
[0034]
13. Using the end face grooving tool (27), the annular groove (28) on the bottom face of the counterbore (24) is deburred (FIG. 3 (c)). That is, 9. The same process is performed to remove the radial bulge caused by burnishing.
[0035]
14 Using a grooving tool (35) or a punch tool, the protrusion (30) is cut by 45 ° to form a straight part (36) on the protrusion (FIG. 3 (d)). The straight portion (36) corresponds to the straight portions (7a) and (8a) of the protrusions (7) and (8) in FIG. 11, and the pipe joint shown in FIG. 11 has the straight portions (7a) and (8a). And the presence of flat surfaces (15), (16), (17), and (18) on both sides of the base of the protrusions (7) and (8) are highly balanced in all properties of sealability, tightening properties and disassembly properties It has become a thing.
[0036]
15. Using the external cutting tool (22), milling full back cermet or carbide tip, the counterbore outer diameter end face (21b) is processed to be flat (FIG. 3 (e)).
[0037]
In the above, as shown in an enlarged view in FIG. 4, the general-purpose tool (29) has a shape having a recess (29a) having an arcuate cross section and flat surfaces (29b) (29c) on both sides of the end face. Yes. The outer flat surface (29c) is projected in the axial direction by an offset amount D from the inner flat surface (29b). As a result, the seal end face shape shown on the left of the figure after the rounding process and before the burnishing process is processed so that the inner flat surface protrudes in the axial direction by an offset amount D from the outer flat surface (32). The On the other hand, the burnishing roll (34) has a shape having an annular recess (34a) having an arcuate cross section and flat circumferential surfaces (34b) (34c) on both sides thereof as shown in an enlarged view in FIG. In addition, the inner and outer circumferential surfaces (34b) and (34c) have the same diameter. Therefore, the burnishing roll (34) strongly hits the inner flat surface (31) of the seal end face with respect to the seal end face shape before burnishing shown on the left in FIG. Then, after the burnishing, as shown on the right side of the figure, the inner flat surface (31) and the outer flat surface (32) are positioned on the same surface corresponding to the shape of the burnishing roll (34). Made. The shape of the burnishing roll (34) is made to strike the inner flat surface (31) of the seal end face more strongly, and after burnishing, the inner flat surface (31) protrudes beyond the outer flat surface (32). Of course, it may be a simple shape.
[0038]
In the above process, burnishing is performed twice in order to stabilize the mirror finish, but this makes it possible to ensure a predetermined hardness from the end face to the inside of 100 microns. Twice machining is also effective in extending the life of the burnishing roller.
[0039]
The burnishing pressure is preferably about 150K, and the burnishing follow-up amount is set to, for example, about 1.5 to 3.5 mm after the roller starts to contact with R. The processing conditions such as the additional amount are appropriately set according to the equipment, the pipe joint material, and the state of the lower processing. The finished state is checked with a stereomicroscope.
[0040]
The seal end face processing method according to the second invention sequentially performs the following steps.
[0041]
1. A cylindrical material (41) having a through-hole (lower hole) (41a) serving as a fluid passage is prepared (FIG. 6 (a)).
[0042]
2. The outer diameter end face (41b) is processed to be flat using an external cutting tool (42), a milling full back cermet or a carbide tip (FIG. 6 (b)).
[0043]
3. Using the drill (43), the fluid passage end inner diameter (44) having a diameter slightly larger than the diameter of the lower hole (41a) is roughly processed (FIG. 6 (c)).
[0044]
4). The counterbore (46) is processed using the end mill (45) (FIG. 6 (d)).
[0045]
5. The inner diameter 44 is finished using an inner diameter tool 47 or an end mill (FIG. 6E).
[0046]
6). The outer diameter end face (41b) after the counterbore (46) is finished using an external cutting tool (42), a milling full back cermet, or a cemented carbide tip (FIG. 7 (a)).
[0047]
7). Using the end face grooving tool (48), an annular groove (49) is formed in the outer peripheral edge of the bottom surface of the counterbore (46) (FIG. 7B).
[0048]
8). An annular protrusion (51) is formed on the bottom surface of the counterbore (46) by using an R-type cutting tool (50) made of ultra-fine particle carbide with a circular arc-shaped recess (50a) for forming the protrusion (51). In addition, a tapered surface (52) is formed inside the protrusion (51), and a flat surface (53) is formed on the outside (referred to as rounding) (FIG. 7C).
[0049]
9. Similarly, by using the R-type cutting tool (54) in which a concave section (54a) having a circular arc section is formed, an annular protrusion (51, a tapered surface (52) inside the protrusion (51) and a flat surface outside the protrusion (51) Each surface (53) is finished (Fig. 7 (d)) The R-type tool bit (54) used in this finishing process is the R-type tool bit (50) used in the first round process. In contrast to an uncoated ultrafine carbide material, a TIN or TIAL coated ultrafine particle carbide material is used.
[0050]
10. Using a drill (43), the chips on the inner diameter (44) of the fluid passage end are removed (FIG. 7 (e)).
[0051]
11. Counterbore (24) bottom projection (51), taper surface (52) inside projection (51) and flat surface (53) outside projection (51) plastic mold steel burnishing roller (56 Is burnished using a burnishing tool (Superoll) (55) having ()) (FIG. 8 (a)).
[0052]
12 Using the end face grooving tool (48), the annular groove (49) on the bottom surface of the counterbore (46) is deburred (FIG. 8B).
[0053]
13. Deburring the inner diameter (44) of the fluid passage end using an inner diameter tool (47) or an end mill (FIG. 8 (c)).
[0054]
In the above, as shown in an enlarged view of FIG. 9, the general-purpose tool (50) used in the roughing of the round process has an arcuate recess (50a) on the end surface and flat surfaces (50b) on both sides thereof. (50c). The inner flat surface (50b) and the outer flat surface (50c) are positioned on the same surface (that is, the offset amount between the two flat surfaces is zero). The total tool (54) used in the round finishing process has the same shape. Further, the burnishing roll (56) has an annular recess (56a) having an arcuate cross section and flat circumferential surfaces (56b) (56c) having the same diameter on both sides as shown in FIG. In addition to the shape, the depth H3 of the recess (56a) is smaller than the height of the protrusion (51). In the rounding process, the height H1 of the protrusion (51) before burnishing shown in the left of FIG. 9 is the protrusion after burnishing shown in the left of FIG. (51) It is made larger than the height H2. Further, the taper angle T1 of the projection (51) before burnishing is smaller than the taper angle T2 of the projection (51) after machining, and the burnishing hits well. Occurrence is prevented. As a result, the shape and dimensions of the projection (51) can be obtained with high accuracy, and the mirror finish and the increase in hardness of the projection (51) can be made with extremely high accuracy.
[0055]
In the first and second inventions, the processing order is not necessarily performed as in the above-described embodiment, and the order can be changed within a range that does not affect the performance of the seal end face. Of course, the first and second inventions may be combined.
[Brief description of the drawings]
FIG. 1 is a diagram showing first to fifth steps of a first embodiment of a seal end face processing method according to the present invention;
FIGS. 2A to 2C are views showing fifth to tenth steps of the first embodiment of the seal end surface processing method according to the present invention; FIGS.
FIGS. 3A to 3C are views showing eleventh to fifteenth steps of the first embodiment of the seal end face processing method according to the present invention; FIGS.
FIG. 4 is a view showing an all-type tool used in the first embodiment of the seal end surface processing method of the present invention.
FIG. 5 is a view showing a burnishing roll used in the first embodiment of the seal end surface processing method of the present invention.
FIG. 6 is a diagram showing first to fifth steps of a second embodiment of the seal end surface processing method according to the present invention;
FIGS. 7A to 7C are views showing fifth to tenth steps of the second embodiment of the seal end face processing method according to the present invention; FIGS.
FIG. 8 is a diagram showing eleventh to thirteenth steps of a second embodiment of the seal end face processing method according to the present invention;
FIG. 9 is a view showing an all-type tool used in the second embodiment of the seal end face processing method of the present invention;
FIG. 10 is a view showing a burnishing roll used in the second embodiment of the seal end face processing method of the present invention.
FIG. 11 is a view showing an example of a pipe joint processed by the seal end face processing method of the present invention.
[Explanation of symbols]
(29) Total bytes
(29b) Inner flat surface
(29c) Outside flat surface
(30) Projection
(31) Inner flat surface
(32) Outside flat surface
(33) Burnishing tool
(34) Burnishing roll
(34b) Inner circumferential surface
(34c) Outer circumferential surface
(35) Grooving tool
(36) Protruding straight part
(51) Protrusion
(50) Total cutting tool for roughing
(50b) Inner flat surface
(50c) Outside flat surface
(54) Complete tool for finishing
(55) Burnishing tool
(56) Burnishing roll
(56a) Recess
(56b) Inner circumferential surface
(56c) Outer circumferential surface

Claims (5)

A method of processing a seal end face having a flat surface that contributes to a seal on at least one of an annular protrusion and a base of the protrusion, and a round process step that simultaneously processes the annular protrusion and the seal-contributing flat surface using a total tool And a burnishing step of simultaneously mirror-finishing and increasing the hardness of the annular projection and the seal-contributing flat surface using a burnishing tool , and the seal end surface has a flat surface that contributes to sealing both inside and outside the base of the projection. The end face shape of the total type bite is characterized in that the outer flat surface is protruded more than the inner flat surface, and the burnishing roll has the same inner and outer circumferential surface diameters. Seal end face processing method. 2. The seal end face processing method according to claim 1, wherein after the first rounding and burnishing are performed, deburring is performed, and further, the second rounding and burnishing is performed. The contour shape of the cross-section of each annular projection consists of an arc portion extending radially outward from the end face of the abutment and a straight portion connected to the arc portion, and the center of the arc portion is more radial than the intersection of the arc portion and the straight portion It is inside, and the straight part is inclined by 30 to 60 ° with respect to the axial direction, and the straight part is inclined by 30 to 60 ° in the axial direction using a grooving tool or a boring tool. 3. The seal end face processing method according to claim 1, wherein the round cut process is performed after the burnishing process and the subsequent deburring process.   The general-purpose bite has a concave shape with an arc-shaped cross section and a flat surface located on the same surface on both sides thereof, and the burnishing roll has an annular concave portion with an arc-shaped cross section and both sides and the same diameter. It has a shape with a flat circumferential surface, the height of the protrusion before burnishing is larger than the height after machining, and the taper angle of the protrusion before burnishing is smaller than the taper angle after machining The seal end face processing method according to claim 1, characterized in that: The rounding process is carried out in two steps: rough machining using a total bite of ultra-fine cemented carbide material and finishing process using a total bite of TIN or TIAL coated ultra-fine carbide material The seal end face processing method according to claim 4 .

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