KR102439898B1 - lack of seal - Google Patents

Abstract

In this sealing member 10, a curved surface 110 and an inclined surface 120 are formed in a region where the first side surface 101 and the third side surface 103 of the heel portion 10h intersect, and the curved surface 110 is formed so as to be in contact with the first side surface 101 and the inclined surface 120 , and the inclined surface 120 is formed to intersect the third side surface 103 .

Description

lack of seal

The present invention relates to a seal structure, and more particularly, to a structure of a seal member used for a sliding gap between a rod (piston rod) and a cylinder in a hydraulic/pneumatic device or the like.

For example, in a sliding gap between a cylinder and a rod (piston rod) in a hydraulic device, leakage of hydraulic oil introduced into the oil chamber (leakage of hydraulic oil from the high pressure side to the low pressure side) is prevented, and the reciprocating motion of the rod is prevented. In order to implement|achieve smoothly, the sealing structure in which a sealing member is fitted in the sealing groove formed in the cylinder is employ|adopted. Such a seal structure is disclosed in Unexamined-Japanese-Patent No. 2005-337440 (patent document 1), Unexamined-Japanese-Patent No. 2014-214769 (patent document 2), etc.

Japanese Laid-Open Patent Publication No. 2005-337440 Japanese Laid-Open Patent Publication No. 2014-214769

In recent years, in order to improve the sealing performance by a sealing structure more, improvement of a sealing member is performed day by day.

This invention was made in order to solve the said subject, Comprising: It is providing the sealing member which makes it possible to improve the sealing performance by a sealing structure more.

In the sealing member based on the present invention, the high-pressure side and the low-pressure side are partitioned in the sliding gap between the cylinder and the rod in the hydraulic/pneumatic device, and accommodated in a seal groove formed in an annular shape along the circumferential direction of the outer peripheral surface of the rod, , A sealing member that blocks a sliding gap between the cylinder and the rod, and has the following configuration.

a heel portion positioned on the low pressure side and a lip portion positioned on the high pressure side, wherein the heel portion includes a first side surface positioned on the rod side, a second side surface positioned opposite the first side surface, and a low pressure side portion and a third side surface, wherein the lip portion has a first lip portion that opens toward the rod side, and a second lip portion that opens toward a side opposite to the rod side, wherein the first side surface and the third side surface of the heel portion are A curved surface and an inclined surface are formed in the intersecting area, the curved surface is formed to be in contact with the first side surface and the inclined surface, and the inclined surface is formed to intersect the third side surface.

In another aspect, the projection length of the curved surface and the inclined surface to the third side surface is 0.3 mm or more and 2 mm or less, and the radius of the curved surface is 2 mm or more and 15 mm or less, and the third of the inclined surface is The inclination angle with respect to 3 side is 30 degrees - 80 degrees.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the sealing structure which makes it possible to improve the sealing performance by a sealing structure more.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the seal structure employ|adopted for the hydraulic device of embodiment.
It is a perspective view which shows the structure of the 1st sealing member of embodiment.
FIG. 3 is a cross-sectional view taken along line III in FIG. 2 .
It is a partial enlarged schematic diagram which shows the sealing state of the 1st sealing member in embodiment.
It is a figure which shows the sealing pressure state of the 1st sealing member at the time of attachment of embodiment.
It is a figure which shows the relationship between the contact width of a 1st sealing member at the time of attachment of embodiment, and a contact surface pressure.
It is a figure which shows the sealing pressure state of the 1st sealing member at the time of pressure load of embodiment.
It is a figure which shows the relationship between the contact width of a 1st sealing member at the time of pressure load of embodiment, and a contact surface pressure.
7 : is sectional drawing which shows the structure of the 1st sealing member in a related art.
It is a partial enlarged schematic diagram which shows the sealing state of the 1st sealing member in a related art.
It is a figure which shows the sealing pressure state in the 1st sealing member at the time of attachment of a related art.
Fig. 9B is a diagram showing the relationship between the contact width and the contact surface pressure when the related art is installed.
It is a figure which shows the sealing pressure state in the 1st sealing member at the time of the pressure load of a related art.
Fig. 10B is a diagram showing the relationship between the contact width and the contact surface pressure at the time of pressure load in the related art.
It is a figure which shows the relationship between the sliding distance and leakage amount of embodiment and a related art.
It is sectional drawing which shows the modification of the 1st sealing member of embodiment.
13 : is sectional drawing which shows the other modified example of the 1st sealing member of embodiment.
14A is a diagram showing a state of a sealing pressure of (R=15, θ=80°, a=0.3) at the time of pressure load in Example 1. FIG.
Fig. 14B is a diagram showing the relationship between the contact width and the contact surface pressure in Example 1 under pressure load.
It is a figure which shows the sealing pressure state of (R=2, (theta)=30 degree, a=2) at the time of the pressure load of Example 2. FIG.
Fig. 15B is a diagram showing the relationship between the contact width and the contact surface pressure in Example 2 under pressure load.
It is a figure which shows the sealing pressure state of (R=0.5, (theta)=30 degree, a=2) at the time of pressure load of Example 3. FIG.
Fig. 16B is a diagram showing the relationship between the contact width and the contact surface pressure in Example 3 under pressure load.

EMBODIMENT OF THE INVENTION Hereinafter, the sealing member in embodiment based on this invention and the sealing structure using the sealing member are demonstrated, referring drawings. In the embodiments described below, when referring to the number, amount, etc., the scope of the present invention is not necessarily limited to the number, amount, etc., except where there is a particular description. The same reference number is attached|subjected about the same component and an equivalent component, and overlapping description may not be repeated. Below, although a hydraulic cylinder is mentioned as an example of a hydraulic/pneumatic device, it is not limited to a hydraulic cylinder, It is possible to apply to a hydraulic/pneumatic device widely.

(seal structure)

With reference to FIG. 1, the seal structure in this embodiment is demonstrated. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the seal structure employ|adopted for the hydraulic cylinder in embodiment. In Fig. 1, the cylinder 1 and the rod (piston rod) 2 are shown by broken lines for convenience of explanation. Although the seal structure shown in FIG. 1 deforms with the pressure contact with the rod 2 and the reciprocating motion of the rod 2 (up-and-down direction in FIG. 1), in order to understand the seal structure clearly, a pressure is applied to the seal structure, The non-existent state is shown.

An annular first seal groove 10G is formed along the circumferential direction of the outer peripheral surface of the rod 2 . The 1st sealing member 10 which closes the sliding clearance gap between the cylinder 1 and the rod 2 is accommodated in this 1st sealing groove 10G.

It is annularly formed along the circumferential direction of the outer peripheral surface of the rod 2, and the 2nd sealing groove 20G is formed in the high-pressure side rather than the 1st sealing groove 10G. In the illustration, a high-pressure hydraulic chamber is formed on the upper side. The 2nd sealing member 20 which closes the sliding clearance gap between the cylinder 1 and the rod 2 is accommodated in the 2nd sealing groove 20G.

(first seal member 10)

With reference to FIG.2 and FIG.3, the 1st sealing member 10 in this embodiment is demonstrated. FIG. 2 : is a perspective view which shows the structure of the 1st sealing member 10, FIG. 3 : is sectional drawing along line III arrow in FIG.

The first sealing member 10 has an annular shape as a whole, and is integrally molded with a synthetic resin such as a urethane resin, a natural rubber, a synthetic rubber, or a fluororubber. The first sealing member 10 has a substantially U-shaped cross-sectional shape having an open side on the high-pressure side.

More specifically, when the cross section shown in FIG. 3 is seen, it is provided with the heel part 10h located at the low pressure side, and the lip part 10r located at the high pressure side. The heel portion 10h includes a first side surface 101 located on the rod 2 side, a second side surface 102 located opposite to the first side surface 101, and a third side surface 103 located on the low pressure side. ) is included.

The lip portion 10r includes a first lip portion 10b that opens toward the rod 2 side, and a second lip portion 10c that opens toward the opposite side to the rod 2 side. A substantially U-shape is formed by the 1st lip part 10b and the 2nd lip part 10c.

Further, in a region where the first side surface 101 and the third side surface 103 of the heel portion 10h, which are the low-pressure side of the rod 2 side viewed from the heel portion 10h, intersect, a curved surface 110, and, An inclined surface 120 is formed. The curved surface 110 is formed so as to contact the first side surface 101 and the inclined surface 120 , and the inclined surface 120 is formed to intersect the third side surface 103 .

Let the projection length of the curved surface 110 and the inclined surface 120 to the third side surface 103 be "a", the radius of the curved surface 110 be "R", and the third side surface of the inclined surface 120 When the inclination angle with respect to (103) is "θ", in order to obtain better sealing properties with respect to the rod 2 in the first sealing member 10, the projection length "a" is 0.3 mm or more and 2 mm or less, The radius "R" of the curved surface 110 may be 2 mm or more and 15 mm or less, and the inclination angle "θ" of the inclined surface 120 with respect to the third side surface 103 may be 30° to 80°. This point is demonstrated in the Example mentioned later.

Again, referring to FIG. 1 , when the rod 2 moves from the low pressure side toward the high pressure side when viewed from the first sealing member 10, it is called a “pulling step”, and the rod 2 is subjected to a high pressure When moving from the side toward the low pressure side, it is called a "push process".

With reference to FIGS. 4-6B, the sealing state of the 1st sealing member 10 is demonstrated. 4 : is a partial enlarged schematic diagram which shows the sealing state in "pulling process", FIG. 5A is a figure which shows the sealing pressure state of the 1st sealing member 10 at the time of attachment, FIG. 5B is a time of attachment 6A is a figure which shows the relationship between the contact width of the 1st sealing member 10 in the case of pressure load, and FIG. 6A is a figure which shows the sealing pressure state of the 1st sealing member 10 at the time of a pressure load, FIG. 6B is, It is a figure which shows the relationship between the contact width of the 1st sealing member 10 at the time of pressure load, and a contact surface pressure. In addition, in FIG. 5A and FIG. 6A, P3 - P10 show the distribution of internal pressure, and it has shown that the internal pressure becomes small toward P10 from P3.

4 and 5A , while the first lip portion 10b has a shape that opens toward the rod 2 side, the first side surface 101 of the heel portion 10h of the first sealing member 10 and the curved surface 110 and the inclined surface 120 are formed in the area where the third side surface 103 intersects, so that the heel portion 10h is in a non-contact state with the rod 2 even when mounted, In the "pulling process", it is possible to easily return the oil OL to the inside of the cylinder 1 .

The first side surface 101 and the third side surface 103 of the heel portion 10h are also evident from the figure showing the relationship between the contact width and the contact surface pressure of the first sealing member 10 at the time of installation in Fig. 5B. In this intersecting region, the peak surface pressure is not generated in the region R1 because it does not contact the rod 2 . On the other hand, since the 1st lip part 10b and the 2nd lip part 10c are fitted by the 1st seal groove 10G and the rod 2 and are greatly deformed, based on the reaction force, the region R2 ((( In the region indicated by P9 in A)), the peak surface pressure due to the contact is generated.

Next, in the region where the first side surface 101 and the third side surface 103 of the heel portion 10h intersect even under pressure load in Figs. 6A and 6B, the curved surface 110, and By forming the inclined surface 120, no peak surface pressure is generated in the region R1, and it is possible to maintain a smooth state of the contact surface pressure even if the contact width moves. As a result, it becomes possible to return the oil into the cylinder 1 with less resistance, and the sealing structure using the first sealing member 10 improves the oil suction characteristic, making it possible to further improve the sealing performance. .

In addition, in FIG. 7, sectional drawing of the 1st sealing member 10X in a related art is shown. It is a figure corresponding to the cross section of the line III-III arrow in FIG. The shape of the 1st lip part 10b of the lip part 10r and the 2nd lip part 10c is the same as that of the 1st sealing member 10 of this embodiment. As for this 1st sealing member 10X, in the area|region where the 1st side surface 101 and the 3rd side surface 103 intersect, only the inclined surface 150 is formed, and the curved surface is not formed.

With reference to FIGS. 8-10B, the sealing state of the 1st sealing member 10X of a related art is demonstrated. Fig. 8 is a partially enlarged schematic view showing the sealing state in the "pulling step", Fig. 9A is a view showing the sealing pressure state of the first sealing member 10X at the time of mounting, Fig. 9B is at the time of mounting Fig. 10A is a diagram showing the relationship between the contact width and the contact surface pressure of the first sealing member 10X in a diagram, Fig. 10A is a diagram showing the sealing pressure state of the first sealing member 10X under pressure load, Fig. 10B is, It is a figure which shows the relationship between the contact width of 10X of 1st sealing member at the time of pressure load, and a contact surface pressure. In addition, in FIG. 9A and FIG. 10A, P3 - P10 have shown the distribution of internal pressure, and it has shown that the internal pressure becomes small toward P10 from P3.

As shown to FIG. 8 and FIG. 9A, as for the 1st sealing member 10X, the curved surface is not formed in the heel part 10h of the 1st sealing member 10X, but only the inclined surface 150 is formed. As a result, at the time of wearing, the heel portion 10h comes into contact with the rod 2, and a peak surface pressure is formed in the region R3 as shown in Fig. 9B. Also, even under pressure load in FIGS. 10A and 10B , in the region where the first side surface 101 and the third side surface 103 of the heel portion 10h intersect, only the inclined surface 150 is the area. A larger peak surface pressure occurs at R4. As a result, at the time of the pulling process, the suction characteristic of oil was bad and it became one factor of the cause of oil leakage.

11, the amount of leakage of the 1st sealing member 10 of embodiment and the 1st sealing member 10X of a related art is contrasted and demonstrated. 11 : is a figure which shows the relationship between the sliding distance of the 1st sealing member 10 of embodiment, and the 1st sealing member 10X of a related art, and leakage amount.

The first sealing member 10 and the first sealing member 10X are both synthetic resins such as urethane resin (hardness durometer A90, tensile strength Mpa 44.0, elongation 500%, compression set 40%, compression set test) Condition 8) (80°C-70 h): manufactured by Nippon Balka Kogyo Co., Ltd., product number R5590)) was used.

The 1st sealing member 10 is R=2mm, (theta)=60 degree, a=0.6mm. The first sealing member 10X has no curved surface, and the inclined surface 150 has R=0 mm, θ=45°, and a=0.5 mm (so-called C-plane=0.5 mm).

In the measurement, only the 1st sealing member was attached in all, and the external leakage amount of the oil from the cylinder 1 was measured. The result is shown in FIG. It has confirmed that the 1st sealing member 10 in this embodiment has favorable sealing performance compared with the 1st sealing member 10X in a related art.

(Example)

12 and 13, the structure of the modification of the 1st sealing member 10 in this embodiment is shown. 12 : shows the shape in the case of the 1st sealing member 10A in which "a" was formed relatively large, and FIG. 13 shows the case of the 1st sealing member 10B in which "theta" was formed relatively large.

14A to 16B, as specific Examples 1 to 3, the relationship between the contact width and the contact surface pressure at the time of pressure load is shown. The 1st sealing member 10 in Example 1 has a shape of R=15, (theta)=80 degree, a=0.3, The 1st sealing member 10 in Example 2 is R=2 , θ=30°, a=2, and the first sealing member 10 in Example 3 has a shape of R=0.5, θ=30°, and a=2. In each figure A, P1-P10 shows the distribution of internal pressure, and has shown that internal pressure becomes small toward P10 from P1.

In the case of Example 1 shown to FIG. 14A and FIG. 14B, the peak surface pressure did not generate|occur|produce in the whole area of the contact width, and since favorable surface pressure was shown, it was confirmed that it has excellent sealing performance.

In the case of Example 2 shown in FIGS. 15A and 15B, compared to Example 1, the peak surface pressure did not occur over the entire contact width, and better surface pressure was exhibited, so it had superior sealing performance. could confirm that

In the case of Example 3 shown in Figs. 16A and 16B, as compared to Example 1, a minute peak surface pressure was generated in a region having a contact width of about 1 mm, compared to Example 1 Although it was not favorable, it was a good point compared with the related art shown to FIG. 10A and FIG. 10B, and it has confirmed that it has favorable sealing performance overall.

According to the above embodiment, in the region where the first side surface 101 and the third side surface 103 of the heel portion 10h intersect, the curved surface 110 and the inclined surface 120 are formed, and the curved surface 110 ) is formed to be in contact with the first side surface and the inclined surface 120 , and the inclined surface 120 is formed to intersect the third side surface 103 . Thereby, the 1st sealing member in this embodiment has favorable sealing performance.

In addition, the projection length "a" of the curved surface 110 and the inclined surface 120 to the third side surface 103 is 0.3 mm or more and 2 mm or less, and the radius "R" of the curved surface 110 is 2 mm or more. By setting it to 15 mm or less and the inclination angle "θ" of the inclined surface 120 with respect to the third side surface 103 is 30° to 80°, it is possible to obtain more preferable sealing performance.

As mentioned above, although embodiment and an Example were described, embodiment disclosed this time is an illustration in all points, and it should be thought that it is not restrictive. The scope of the present invention is indicated by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

1: Cylinder
2: load
10, 10A, 10B: 1st seal member
10G: first seal groove
10h: heel
10r: lip
20: 2nd seal member
20G: 2nd seal groove
101: first aspect
102: second side
103: third aspect
10b: first lip part
10c: second lip portion
110: curved surface
120: slope

Claims (2)

In a sliding gap between a cylinder and a rod in a hydraulic/pneumatic device, a high-pressure side and a low-pressure side are partitioned and accommodated in a seal groove formed in an annular shape along the circumferential direction of the outer circumferential surface of the rod, the sliding gap between the cylinder and the rod As a sealing member to prevent
A heel part located on the low pressure side,
Including a lip located on the high-pressure side,
The heel part,
a first side surface located on the rod side, a second side surface located opposite to the first side surface, and a third side surface located on the low pressure side;
The lip part,
a first lip portion that opens toward the rod side, and a second lip portion that opens toward a side opposite to the rod side;
A curved surface and an inclined surface are formed in a region where the first side surface and the third side surface of the heel part intersect,
The curved surface is formed to be in contact with the first side surface and the inclined surface,
The inclined surface is formed to intersect the third side surface,
A projection length of the curved surface and the inclined surface to the third side surface is 0.3 mm or more and 2 mm or less,
The radius of the curved surface is 2 mm or more and 15 mm or less,
and an inclination angle of the inclined surface with respect to the third side surface is 30° to 80°. delete

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