JP6346607B2 - Reciprocating seal - Google Patents

Description

  The present invention relates to a reciprocating seal.

  2. Description of the Related Art Conventionally, in a pneumatic equipment cylinder or the like, a reciprocating seal that is mounted in one of the annular concave grooves of a sliding member that is axially slidable mutually has a cross-sectional shape of a sliding head and A vertically long dharma shape composed of a central neck portion and a trunk portion, in which small protrusions are arranged at both sides of the sliding head at a predetermined pitch in the circumferential direction (for example, see Patent Document 1).

  However, the sliding part (the tip side of the sliding head) has a large round shape, and there is a drawback that the sliding resistance is large. In addition, the number of small protrusions is as small as 4 to 8 on one side, and there is a disadvantage that the seal meanders or is eccentric in the groove and the resistance is unstable. In addition, there is a drawback that leakage (blowing leakage) occurs from a location where the surface pressure is locally low on the circumference. In addition, there is a drawback in that it adheres to the side surface of the groove, the pressure does not reach the bottom of the groove, the self-sealing property is lowered, and the sealing property is poor.

  In recent years, reciprocating seals are required to have low sliding resistance and response speed due to environmental considerations. Furthermore, due to lower prices, reciprocating seals that are not equipped with wear rings (eccentricity reducing members) have increased. However, for example, since the piston is likely to be eccentric with respect to the inner surface of the cylinder tube, there is a disadvantage that the sealing performance is lowered due to the lack of wear ring.

Japanese Utility Model Publication No. 5-79128

  The problem to be solved is a large sliding resistance and starting resistance. Further, the seal meanders or decenters in the groove, and the resistance is unstable. That is, there is a phenomenon in which leakage (blowing leakage) occurs from a location where the surface pressure is locally low on the circumference. Moreover, it adheres to the side surface of the groove, and the pressure does not reach the bottom of the groove, so that the self-sealing property cannot be obtained sufficiently. In addition, the sealing performance is inferior.

Therefore, the reciprocating seal according to the present invention is a reciprocating seal that is mounted in any one of the annular concave grooves of the sliding members that are axially slidable with respect to each other. A rectangular body portion and a groove bottom side bulge portion, and the groove bottom side corner portion of the bulge portion is formed in an arc shape or a C-shaped chamfered shape to form a gap at the corner of the groove bottom A plurality of small protrusions projecting at a predetermined pitch in the circumferential direction on the front and back surfaces of the rectangular body, and the position of the center of gravity in the outer shape of the small protrusions Are radially outwardly distributed so as to be closer to the outer peripheral edge than to the inner peripheral edge of the above-described front and back surfaces of the ring-shaped belt having a constant width dimension in the radial direction.

Further, the reciprocating seal according to the present invention is a reciprocating seal mounted in any one of the annular concave grooves of the sliding members that are axially slidable with respect to each other. A rectangular body portion and a groove bottom side bulge portion, and the groove bottom side corner portion of the bulge portion is formed in an arc shape or a C-shaped chamfered shape to form a gap at the corner of the groove bottom A plurality of small protrusions projecting at a predetermined pitch in the circumferential direction on the front and back surfaces of the rectangular body, and the small protrusions have an area of 85% or more of the base cross-sectional area. A table mountain type having a flat front end surface with the apex angle θ of the triangular apex set to 80 ° ≦ θ ≦ 120 °.
Further, the reciprocating seal according to the present invention is a reciprocating seal mounted in any one of the annular concave grooves of the sliding members that are axially slidable with respect to each other. A rectangular body portion and a groove bottom side bulge portion, and the groove bottom side corner portion of the bulge portion is formed in an arc shape or a C-shaped chamfered shape to form a gap at the corner of the groove bottom A plurality of small protrusions protruding at a predetermined pitch in the circumferential direction on the front surface and the back surface of the rectangular body, and a plurality of small protrusions disposed on the front surface at the predetermined pitch. And a plurality of small protrusions arranged at the same predetermined pitch on the back surface are shifted in the circumferential direction by a half of the predetermined pitch , and each dimension is as follows. In this case, the following formula is established.
(H ₁ + H ₂ ) ≧ 0.6 · H ₀
(H ₁ + H ₂ ) / 3 ≦ B ₇ ≦ 2 · (H ₁ + H ₂ ) / 3
πD / 5N ≦ C ₇ ≦ πD / 1.3N
However,
H ₁ : Height of the top
H ₂ : Body height dimension
H ₀ : Overall seal height dimension
B ₇ : Radial dimension of the base of the small protrusion
C ₇ : Circumferential dimension of the base of the small protrusion
D: outer diameter of the seal
N: Number of small protrusions on the front and back surfaces

According to the present invention, the triangular top portion is in sliding contact with the mating sliding member and exhibits excellent sealing performance (sealing performance), and the sliding resistance is stabilized and reduced. Contributes to fluid equipment responsiveness and energy saving. Furthermore, since the starting resistance is small and the starting resistance value is stable, the responsiveness of the reciprocating fluid device can be further improved. Also, in reciprocating air devices such as air cylinders, the grease for lubrication can be securely held, and the sliding resistance can be kept low over a long period of use (long-term use without lubrication is possible).
Furthermore, the reciprocating seal of the present invention has an excessively curved cross-sectional shape in the annular groove even when the fluid pressure changes and when the reciprocating speeds of sliding, stopping and starting change. Or maintaining a stable posture without generating deformation that becomes inclined, and does not deform in a meandering shape (as viewed from the radial outer direction), and has a stable sealing performance (sealing performance), excellent It has excellent durability and does not cause leakage.
Further, since the small protrusions are arranged in the form of dots, it is easy to process the small protrusion forming portion of the mold (compared to radial small protrusions in the radial direction).

It is a perspective view which shows the 1st Embodiment of this invention. It is principal part sectional drawing. It is principal part sectional drawing which shows 2nd Embodiment. It is principal part sectional drawing which shows 3rd Embodiment. It is use condition explanatory drawing for demonstrating an effect | action. FIG. It is the whole view seen from the axial direction which shows 4th Embodiment. It is a principal part enlarged view of FIG. It is the whole view seen from the axial direction which shows 5th Embodiment. It is a principal part enlarged view of FIG. It is principal part sectional drawing. It is pressure distribution explanatory drawing in use condition. It is a perspective view of the Example from which a small protrusion differs.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
1 and 2 show a first embodiment of the present invention. The reciprocating seal of the present invention is used as a reciprocating fluid device, for example, as a seal for a piston or rod of an air cylinder, and is a sliding member X, Y (slidable in the axial direction). 5 (see FIG. 6) and used in the annular groove G. Various rubber materials can be applied as the material.

In FIG. 2, the cross-sectional shape has a triangular top portion 1, a rectangular body portion 2, and a groove bottom side bulging portion 3, as shown by being partitioned by a two-dot chain line. The groove bottom side corner 4 of the bulging portion 3 is formed in an arc shape, and is configured to form a gap S at the corner C of the groove bottom G ₁ (as shown in FIGS. 5 and 6). .
In FIG. 2 (and FIG. 4 described later), the groove bottom corresponding surface 14 of the bulging portion 3 is exemplified as a circular arc shape having substantially the same radius of curvature as a whole. The arc shape is formed in an arc shape by itself. Unlike this, it is preferable that the central region of the groove bottom corresponding surface 14 and the groove bottom side corners 4 and 4 have different curvature radii (not shown).

A plurality of small ridge-shaped projections 7 are provided on the front surface 5 and the back surface 6 of the body 2 at a predetermined pitch P ₇ (in a dotted pattern) in the circumferential direction. The small protrusions 7 on the surface 5 side and the small protrusions 7 on the back surface 6 are provided in a staggered manner. In other words, a plurality of small protrusions 7 arranged on the surface 5 at a predetermined pitch P ₇ and a plurality of small protrusions 7 arranged on the back surface 6 at the same predetermined pitch P ₇ are predetermined. Only half the pitch (0.5 · P ₇ ) is shifted in the circumferential direction.
Then, the small protrusion 7 is formed in a mirror shape (a bowl shape) and has a top flat surface 8.

  The apex angle θ of the triangular apex 1 is set to 80 ° ≦ θ ≦ 120 °. When the apex angle θ is θ <80 °, wear tends to occur. When the apex angle θ is 120 ° <θ, the elasticity is poor.

  As shown in FIGS. 5 and 6, a gap 9 is formed between the small protrusion 7 and the groove bottom side bulging portion 3, and the seal abuts against the groove side surface 15 (or 16) of the groove G. Under the condition, a gap 9 is formed between the front surface 5 or the rear surface 6 on the contact side and the groove side surfaces 15 and 16. The gap 9 is a grease reservoir, and a fluid (for example, air) can surely flow into the gap 9 to ensure the self-sealing property of the seal.

FIG. 3 shows a second embodiment. The groove bottom side corner portion 4 of the bulging portion 3 is formed in a C-shaped chamfered shape so that a gap S is formed at the corner portion C of the groove bottom G ₁ (see FIGS. 5 and 6). In FIG. 3, the groove bottom corresponding surface 14 is illustrated as having a trapezoidal shape with the central region being straight, but the central region may be arcuate (not shown). Further, in FIG. 3, the small protrusions 7 on the surface 5 and the small protrusions 7 on the back surface 6 are not in a staggered pattern (described above). That is, the case where it has arrange | positioned in the front and back same position in the circumferential direction is shown. Other configurations are the same as those of the first embodiment.

FIG. 4 shows a third embodiment. The small protrusions 7 are formed in a wisteria type (mortar type). Other configurations are the same as those of the first embodiment.
Additional features that are common to each of the embodiments of FIGS.
(i) The front surface 5 and the rear surface 6 are flat surfaces parallel to each other, and the conventional seal described above (Patent Document 1).
(Refer to the above), the body portion 2 does not have a concave portion, and the rigidity of the body portion 2 is increased.
(ii) When the thickness dimension of the body part 2 is W ₂ , the thickness dimension of the bulging part 3 is W ₃ , and the distance dimension between the top flat surfaces 8 and 8 is W ₈ , the following equation is established.
0.6 · W ₃ ≤W ₂ ≤0.8 · W ₃ (Formula 1)
0.95 ・ W ₃ ≦ W ₈ ≦ 1.0 ・ W ₃ (Formula 2)
That is, since the thickness dimension W ₂ of the trunk portion 2 is sufficiently large as in Equation 1, the top flat surface 8 is pressed against the groove side surfaces 16 and 15 simultaneously with the bulging portion 3 according to Equation 2, As shown in FIGS. 5 and 6, the body portion 2 is kept in a stable posture at all times with almost no bending deformation, does not meander in the concave groove G, and the triangular top portion 1 is stable against the mating sliding surface. It can be elastically pressed to exhibit excellent sealing performance (sealing performance).
(iii) The upper and lower end surfaces 17 and 18 of the bulging portion 3 are formed as flat surfaces, and are set to 40% to 60% of the height dimension H ₃ of the bulging portion, as shown in FIGS. Contact the side surfaces 15 and 16 with appropriate surface pressure.
(iv) The overall height of the seal is H ₀ , the height of the body 2 is H ₂ , and the height of the bulge 3 is H _3.
Then, the following formula is established.
0.4 · H ₀ ≤ H ₂ ≤ 0.6 · H ₀ (Formula 3)
0.2 · H ₀ ≤ H ₃ ≤ 0.4 · H ₀ (Formula 4)
That is, as can be seen from Equation 3, the body 2 having a rectangular cross section occupies a large height dimension (the width dimension in the radial direction), and contributes to maintaining a stable posture in the groove G. In addition, the function of maintaining a constant radial urging force in the radial direction is exhibited, and the top portion 1 is elastically pressed against the mating sliding surface with an appropriate surface pressure as shown in FIG. As a result, the sealing performance is stable and excellent.
(v) When the height dimension from the groove bottom corresponding surface 14 to the center axis of the small protrusion 7 is H ₇ , the following equation is established.
0.45 ・ H ₀ ≦ H ₇ ≦ 0.75 ・ H ₀ (Formula 5)
That is, the position where the small protrusion 7 is disposed is in the central region of the overall seal height dimension H ₀ , and moves from the tip to the central region as compared with the conventional seal (prior art document 1). It is arranged. As described above, the bending (elastic) deformation of the entire seal is small in combination with the point that the rigidity of the body portion 2 is higher than that of the conventional example, the cross-sectional shape of the seal is more stable, and the triangular top portion 1 is flexibly elastic. As a result, excellent sealing performance can be exhibited while being deformed.
(vi) The outer diameter dimension of the base of the small protrusion 7 is B ₇ and the pitch of the small protrusions 7 is P ₇ (see FIG. 1).
Then, the following equation is established.
1.3 ・ B ₇ ≦ P ₇ ≦ 3.0 ・ B ₇ (Formula 6)
More preferably,
1.5 · B ₇ ≤ P ₇ ≤ 2.5 · B ₇ (Formula 7)
And
That is, as shown in Equation 6 (or Equation 7), by arranging the small protrusions 7 with a relatively small pitch P ₇ , the seal (as viewed from the radial outside direction) is provided together with the rigidity of the body portion 2. Can be reliably prevented. In the case of P ₇ <1.3 · D _7, the number of small protrusions 7 is unnecessarily large, and the manufacturing cost of the mold increases. Moreover, there is a possibility that normal elastic deformation becomes difficult due to the confinement of the fluid. 3.0 When D ₇ <P ₇ , the seal may meander in the circumferential direction.
(vii) As shown in FIG. 2, with respect to the straight line L ₀ , the cross-sectional shape is set to be vertically symmetrical (excluding the small protrusion 7). In addition, if the small protrusions 7 on the upper surface and the lower surface are not disposed in a staggered manner but are disposed at the same circumferential position, the small protrusions 7 are vertically symmetrical including the small protrusions 7 (see FIG. 3).

Next, referring to FIGS. 5 and 6, the operation of the reciprocating seal according to the present invention in use will be described.
As shown in FIG. 5, a case where pressure is applied from the upper side to the lower side as indicated by an arrow p in a state where the reciprocating seal is disposed on the upper side (one side surface) of the annular groove G is considered. Then, due to the structural features described in the above items (i) to (vii), it is possible to prevent the sticking of the seal to the groove side surface 15 which has occurred in the seal of the conventional example (see Prior Art Document 1). As a result, conventional blow-off can be prevented.
Specifically, in the conventional example, since the shape of the small protrusion was a round shape of the top portion, it was crushed when an excessive compressive force was applied, and the seal body was fixed to the groove side surface 15. In particular, because of the large pitch of the small protrusions, such sticking occurs further, and the pressure P cannot penetrate between the groove side surface 15 and the seal and passes through the top. However, in the present invention, the shape of the small protrusion 7 has the top flat surface 8, the compression internal stress is reduced, and the arrangement pitch P ₇ is sufficiently small. 5 can further reduce the compressive internal stress of the small protrusion 7 so that the gap 9 is always formed and held, and with the introduction of the pressure P, the seal moves in the direction of arrow A in FIG. Then, it can be switched immediately to the sealed state as shown in FIG. That is, it is in a pressure contact (close contact) state with the lower groove side surface 16 in FIG.

  FIG. 6 shows the contact surface pressure distribution between the sliding members X and Y and the reciprocating seal. The smaller the total contact surface pressure (area in the range Q) on the sliding surface W, the smaller the sliding resistance. Further, the larger the peak value (maximum value) L of reaction force, the better the sealing performance. In the present invention, since the top portion 1 is triangular, the total reaction force is small (width is small), the peak value is large, sliding resistance is small, and excellent sealing performance (sealing performance) is exhibited. .

  In addition, the shape of the small protrusion 7 is more preferable in the mirror type (FIGS. 2 and 3) than in the Fujitsubo type (FIG. 4) because the amount of rubber is large and the internal stress received during compression deformation can be reduced. Further, the reciprocating seal of the present invention can be used not only for pneumatic equipment but also for fluid such as hydraulic pressure as long as it is for low pressure.

Next, a fourth embodiment of the present invention shown in FIGS. 7, 8, and 11 will be described. Other than the shape and arrangement of the small protrusions 7, the shape, dimensions, etc. of the portions (bulging portion 3, body portion 2, top portion 1, etc.) are the first to third embodiments described above (FIGS. 1 to 6). Since this is the same as above, a duplicate description is omitted.
Hereinafter, features different from those of the first to third embodiments will be mainly described.

7, 8, and 11, the shape of each small protrusion 7 is a substantially trapezoidal shape (the corner is a small radius) when viewed from the axial direction of the seal. In addition, the small protrusion 7 rises with a steep inclination angle β of 85 ° to 90 ° from the surface 5 and the back surface 6 when the peripheral wall surface 10 appears. Then, assuming that the area of the tip flat surface 8 is S ₈ and the small protrusion base cross-sectional area is S ₇ , 0.85 ≦ S ₈ / S ₇ ≦ 0.10 and the table mountain type is obtained. In this way, each small protrusion 7 is a table mountain type (trapezoidal mountain type) provided with the tip flat surface 8 having an area S ₈ that is 85% or more of the base cross-sectional area S ₇ (see FIG. 11). 7 and 8, each small protrusion 7 is shown by a single line, β = 90 °, and S ₈ / S ₇ is 100%.

Next, as is apparent from FIGS. 7, 8, and 11, the position of the center of gravity G ₀ in the outer shape of the small protrusion 7 is an annular band-shaped table having a constant width dimension H ₂ as a whole in the radial direction. Therefore, the outer circumferential edge 22 is unevenly distributed in the radial outer direction R so as to be closer to the outer circumferential edge 22 than to the inner circumferential edge 21 of the surfaces 5 and 6. Here, the constant width dimension H ₂ of the inner peripheral edge 21 and the outer peripheral edge 22 of the annular surface 5 and the rear surface 6 is the height dimension of the body portion 2 described above. In the cross-sectional view of FIG. 11, the inner peripheral edge 21 and the outer peripheral edge 22 are indicated by black circles. In short, the center of gravity G ₀ of the geometrical shape of the small protrusion 7 is unevenly distributed so as to approach the triangular apex 1 on the surface 5 and the back surface 6 of the constant width dimension H ₂ . In other words, the following formula is established.
H ₇ > H ₃ + 1/2 · H ₂ (Formula 8)
Further, as shown in FIGS. 7, 8, and 11, a plurality of small protrusions 7 arranged on the front surface 5 at a predetermined pitch P _{7 and} arranged on the back surface 6 at the same predetermined pitch P ₇ . The plurality of provided small protrusions 7 are arranged so as to be shifted in the circumferential direction by a half of the predetermined pitch 0.5 · P ₇ , and are provided in a staggered manner (as described above).

Next, a fifth embodiment shown in FIG. 9, FIG. 10, and FIG. 11 (common to the above-described fourth embodiment) will be described. The shape of the small protrusion 7 includes an oblong portion 11 that is elongated in the circumferential direction and a rounded short leg portion 12 that protrudes radially inward from the circumferential center of the oval portion 11. Since the other configuration is the same as that of the fourth embodiment, the redundant description is omitted.
13 (B) is a perspective view of the small protrusion 7 of FIGS. 7 and 8, and FIG. 13 (C) is a perspective view of the small protrusion 7 of FIGS.
FIG. 13A shows a circular table mountain type, and the small tip (top) flat surface 8 shown in FIG. 1, FIG. 2, or FIG. 4 is set to 85% or more of the area of the base flat surface. It is also preferable to do this. FIG. 13D shows a table mountain type having a substantially triangular shape with corners having a small round shape.
Incidentally, in the configuration of FIG. 13 (B) (C) (D), the center of gravity G ₀ peripheral edge 22 (see FIGS. 7 and 9) it is possible to further approach the.

Next, in FIG. 7, FIG. 8, or FIG. 9, FIG. 10, and FIG.
H ₁ : Height of top 1
H ₂ : Body 2 height dimension
H ₀ : Overall seal height dimension
B ₇ : Radial dimension of the base of the small protrusion 7
C ₇ : Circumferential dimension of the base of the small protrusion 7
D: outer diameter of the seal
N: If the number of small protrusions 7 on each of the front and rear surfaces is expressed, it is desirable to set the dimensions of each part so that the following mathematical formula is established.
(H ₁ + H ₂ ) ≧ 0.6 · H ₀ (Equation 9)
(H ₁ + H ₂ ) / 3 ≦ B ₇ ≦ 2 · (H ₁ + H ₂ ) / 3 (Formula 10)
πD / 5N ≦ C ₇ ≦ πD / 1.3N (Formula 11)
In Equation 11 above, C ₇ When the value of is close to the upper limit value, the small protrusions 7 and 7 arranged in a staggered manner on the front surface 5 and the back surface 6 partially overlap each other. Conversely, C ₇ When the value of approaches the lower limit value, the arrangement is such that the front and back do not partially overlap. When viewed in the axial direction in the pressure-receiving state, the former is less likely to be deformed in a meandering manner, has excellent sealing performance, and is excellent in durability as a seal.

By the way, the seals of the first to third embodiments (FIGS. 1 to 6) are suitable for use at a relatively low pressure, and the speed and frequency of use alternately between FIG. 5 and FIG. Is also preferable. FIG. 12A shows the contact surface pressure distribution of the first to third embodiments, and FIG. 12B shows the contact surface of the fourth to fifth embodiments (FIGS. 7 to 11). FIG. 12B shows the pressure distribution and shows that the peak value (Pmax) of the contact surface pressure when subjected to the same fluid pressure can be significantly reduced in FIG.
Therefore, it is shown that the seals of the fourth to fifth embodiments (FIGS. 7 to 11) can cope with higher fluid pressure. In particular, in FIG. 12 (A), even when it is repeatedly used at a high fluid pressure up to a cross-sectional shape as indicated by a two-dot chain line Z, it will be worn out and cannot withstand the use of high pressure and high repetition. In some cases, however, in FIG. 12B, it can withstand repeated use at a high fluid pressure, and early wear can be prevented.
As shown in FIG. 6, when the fluid pressure acts by the arrow p, a favorable sealing performance and durability are exhibited at a low pressure. However, when the fluid pressure p that repeatedly acts is extremely high, as shown in FIG. 12A, the top portion 1 repeats rocking in the direction of the arrow M _1, and the top portion 1 is worn like a two-dot chain line Z. At the same time, the small protrusions 7 are not able to withstand the high surface pressure Pmax, and wear early and wear down to the position of the two-dot chain line Z. Therefore, it results in a bad result that promotes early wear of the seal top _{1 in the} direction of the arrow M ₁ .

In FIG. 12 (B) (FIGS. 7 to 10, FIG. 13), such problems are solved, high fluid pressure, corresponding to the repetition of frequent reciprocating seal top 1 the arrow M ₁ direction Only a slight elastic deformation occurs at the top, so that wear of the seal top 1 can be prevented and wear of the small protrusions 7 themselves can also be prevented.
Further, according to the small protrusion 7 having the shape shown in FIGS. 13B to 13D, the pressure receiving portion (tip flat portion 8) is close to the outer peripheral edge 22 of the body portion 2 in FIG. The reaction force against the rocking of the top _{1 in the} direction of the arrow M ₁ is generated in the vicinity of the outer peripheral edge 22 to reliably prevent the rocking (falling) of the top _{1 in the} direction of the arrow M _1. To do.

As described above, according to the present invention, the cross-sectional shape of the reciprocating seal mounted in either one of the annular grooves G of the sliding members X and Y that are slidable in the axial direction is triangular. It has a top portion 1, a rectangular body portion 2, and a groove bottom side bulge portion 3, and a groove bottom side corner portion 4 of the bulge portion 3 is formed in an arc shape or a C-shaped chamfered shape. _A gap S is formed at _one corner C, and a plurality of small ridges 7 are protruded from the front surface 5 and the rear surface 6 of the body 2 at a predetermined pitch P _{7 in the} circumferential direction. Therefore, various performances required for the reciprocating seal are excellent. That is, sliding resistance can be reduced and sealing performance (sealing performance) is good. Moreover, the self-sealing property is good and the eccentric followability is also excellent.

Further, the starting resistance is reduced and the responsiveness is good. Furthermore, it is possible to prevent blow-out. Also, it has good grease retention and can be used without lubrication. Further, the groove bottom side corner 4 of the bulging portion 3 is formed in an arc shape or a C-shaped chamfered shape so as to form a gap S in the corner C of the groove bottom G _1. Is performed smoothly and stably, and the reaction force can be reduced.

Moreover, since the apex angle θ of the triangular apex 1 is set to 80 ° ≦ θ ≦ 120 °, the sealing property is good and the durability is excellent.
Further, since the small ridge-shaped small protrusion 7 has the top flat surface 8, when pressed against the groove side surface 16, the internal stress of the small protrusion 7 can be reduced, and the gap 9 shown in FIG. 5 is always formed. As soon as the pressure P is introduced, it moves in the direction of arrow A and switches to the sealed state shown in FIG. 6 (blow-off can be prevented).

In addition, since the small protrusion 7 is a table mountain type having a flat front end surface 8 having an area S ₈ that is 85% or more of the base cross-sectional area S ₇ , the pressure receiving surface pressure P of the small protrusion 7 at the time of pressure receiving is small. The curve becomes gentle (see FIG. 12 (B)), the wear resistance of the small protrusion 7 itself is improved, the life as a seal is extended, and in particular, it can withstand frequent repeated operations with high-pressure fluid. .
In addition, since the peripheral wall surface 10 of the small protrusion 7 rises from the front surface 5 and the back surface 6 of the body portion 2 with a steep inclination angle β of 85 ° to 90 °, A small protrusion 7 is provided on the surface 5 and the rear surface 6 of an annular belt having a narrow width dimension H ₂ , and the contact area of the tip flat surface 8 of the small protrusion 7 can be sufficiently increased. The pressure-receiving surface pressure P under the state can be reduced, and early wear of the small protrusions 7 can be prevented.

Further, the position of the center of gravity G ₀ in the outer shape of the small projection 7 is larger than the inner peripheral edge 21 of the surface 5 and the rear surface 6 of the annular surface having a constant width H _{2 in} the radial direction. Since the configuration is unevenly distributed radially outward R so as to approach the outer peripheral edge 22, the top portion 1 (with the trunk portion 2) falls in the direction of the arrow M _{1 in} FIG. When trying (swinging), an effective support reaction force can be generated by the small protrusion 7.
In addition, a plurality of small protrusions 7 disposed on the surface 5 with the predetermined pitch P ₇ and a plurality of small protrusions 7 disposed on the back surface 6 with the same predetermined pitch P ₇ . Since the position is shifted in the circumferential direction by half of the predetermined pitch (0.5 · P ₇ ), the seal can be prevented from elastically deforming in a meandering manner in the circumferential direction when viewed from the radial inner direction, and sealing performance To fully demonstrate.

In addition, the following mathematical formulas were established for the following dimensions.
(H ₁ + H ₂ ) ≧ 0.6 · H ₀
(H ₁ + H ₂ ) / 3 ≦ B ₇ ≦ 2 · (H ₁ + H ₂ ) / 3
πD / 5N ≦ C ₇ ≦ πD / 1.3N
H ₁ : Height of top 1
H ₂ : Body 2 height dimension
H ₀ : Overall seal height dimension
B ₇ : Radial dimension of the base of the small protrusion 7
C ₇ : Circumferential dimension of the base of the small protrusion 7
D: outer diameter of the seal
N: Number of small projections 7 on each of the front and back surfaces. Accordingly, the body 2 and the top 1 can be elastically deformed flexibly, and the small projection 7 can be applied to the groove side surface 16 at a low surface pressure. In contact, excessive elastic deformation of the body 2 and the top 1 is prevented over a long period of time. Furthermore, when the small protrusions 7 are arranged in a staggered manner on the front surface 5 and the rear surface 6, some of them correspond to the seal usage conditions (fluid pressure, reciprocating speed, required sliding distance, reciprocating operation frequency, etc.) They can be arranged so that they overlap, or conversely, do not overlap.

1 (triangular) top 2 (rectangular) body 3 (groove bottom side) bulging portion 4 groove bottom side corner 5 front surface 6 back surface 7 small protrusion 8 flat end surface (top flat surface)
10 Surrounding wall
21 Inner edge
22 Outer peripheral edge B ₇ Radial dimension of the base of the small protrusion C Corner C ₇ Circumferential dimension of the base of the small protrusion D Seal outer diameter G Ring groove G ₁ Groove bottom H ₀ Overall seal height H ₁ Height dimension of the top part H ₂ Height dimension of the body part
N Number of small protrusions P ₇ pitch R Radial outward direction S Clearance X Sliding member Y Sliding member β Inclination angle θ Vertical angle

Claims (3)

In the reciprocating seal mounted in any one of the annular grooves (G) of the sliding members (X) and (Y) that can slide in the axial direction with respect to each other,
The cross-sectional shape has a triangular top (1), a rectangular body (2), and a groove bottom side bulge (3), and the groove bottom side corner (4) of the bulge (3). ) Is formed in an arc shape or a C-shaped chamfered shape, and a gap (S) is formed in the corner (C) of the groove bottom (G ₁ ),
A plurality of small protrusions (7) are projected in a dotted manner in the circumferential direction at a predetermined pitch (P ₇ ) on the front surface (5) and the back surface (6) of the rectangular body (2) ,
The position of the center of gravity (G ₀ ) in the external shape of the small protrusion (7) is the annular surface having the constant width dimension (H ₂ ) in the radial direction as described above (5) and back surface (6) A reciprocating seal characterized in that it is unevenly distributed radially outward (R) so as to be closer to the outer peripheral edge (22) than to the inner peripheral edge (21) . In the reciprocating seal mounted in any one of the annular grooves (G) of the sliding members (X) and (Y) that can slide in the axial direction with respect to each other,
The cross-sectional shape has a triangular top (1), a rectangular body (2), and a groove bottom side bulge (3), and the groove bottom side corner (4) of the bulge (3). ) Is formed in an arc shape or a C-shaped chamfered shape, and a gap (S) is formed in the corner (C) of the groove bottom (G ₁ ),
A plurality of small protrusions (7) are projected in a dotted manner in the circumferential direction at a predetermined pitch (P ₇ ) on the front surface (5) and the back surface (6) of the rectangular body (2). The small protrusion (7) is a table mountain type having a flat tip surface (8) having an area (S ₈ ) of 85% or more of its basal cross-sectional area (S ₇ ) ,
A reciprocating seal, wherein the apex angle (θ) of the triangular apex (1) is set to 80 ° ≦ θ ≦ 120 °. In the reciprocating seal mounted in any one of the annular grooves (G) of the sliding members (X) and (Y) that can slide in the axial direction with respect to each other,
The cross-sectional shape has a triangular top (1), a rectangular body (2), and a groove bottom side bulge (3), and the groove bottom side corner (4) of the bulge (3). ) Is formed in an arc shape or a C-shaped chamfered shape, and a gap (S) is formed in the corner (C) of the groove bottom (G ₁ ),
A plurality of small protrusions (7) are projected in a dotted manner in the circumferential direction at a predetermined pitch (P ₇ ) on the front surface (5) and the back surface (6) of the rectangular body (2) ,
A plurality of small projections disposed at the predetermined pitch (P ₇₎ on the surface (5) Te Table (7), disposed on the rear surface (6) in the same said predetermined pitch (P ₇₎ A plurality of small protrusions (7) are arranged with their positions shifted in the circumferential direction by half of the predetermined pitch (0.5 · P ₇ ),
A reciprocating seal characterized in that the following formula is established for each of the following dimensions:
(H ₁ + H ₂ ) ≧ 0.6 · H ₀
(H ₁ + H ₂ ) / 3 ≦ B ₇ ≦ 2 · (H ₁ + H ₂ ) / 3
πD / 5N ≦ C ₇ ≦ πD / 1.3N
However,
H ₁ : Height of top (1)
H ₂ : Body (2) height dimension
H ₀ : Overall seal height dimension
B ₇ : Radial dimension of the base of the small protrusion (7)
C ₇ : Dimension in the circumferential direction of the base of the small protrusion (7)
D: outer diameter of the seal
N: Number of small protrusions (7) on the front and back surfaces

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