JP2019148283A - Seal material - Google Patents

Abstract

To provide a seal material having a configuration capable of further suppressing high-pressure hydraulic oil from being accumulated between a first seal material and a second seal material.SOLUTION: An annular sealing material 100 is provided in a sliding interval between a cylinder and a rod in a hydraulic/pneumatic device, and partitions a high-pressure side and a low-pressure side that are placed in a sealing groove provided in the cylinder. The annular sealing material comprises: an annular seal body 10; a pressure accumulation preventing groove 11 provided on the high-pressure side of the sealing material body 10, and extending in a radial direction; and a pressure accumulation opening groove 12 provided at a position corresponding to the pressure accumulation prevention groove 11 on the outer peripheral side surface of the seal body 10, and having a form extending along a sliding direction of the rod.SELECTED DRAWING: Figure 5

Description

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

  In the sliding gap between the cylinder and the rod (piston rod) in hydraulic equipment, 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 rod reciprocates. In order to realize smoothly, a seal structure in which a seal material is fitted into a seal groove provided in the cylinder is employed. Such a sealing structure is disclosed in Japanese Patent Application Laid-Open No. 2014-214768 (Patent Document 1).

JP 2014-214768 A

  In recent years, specifications that further improve the sealing performance of the sealing structure have been demanded. On the other hand, in the seal structure disclosed in Patent Document 1, high-pressure hydraulic oil may be accumulated between the first seal material and the second seal material located on the high-pressure side. In order to release this accumulated hydraulic fluid to the high pressure side, a structure has been developed in which a pressure accumulation preventing groove is provided on the high pressure side surface of each sealing material.

  However, even when the pressure accumulation prevention groove is provided in this way, the seal material is brought into close contact with the seal groove by pressing the outer peripheral surface side of each seal material to the bottom surface of the seal groove, and the operation to the high pressure side is performed. An oil escape route is not secured, and there is a concern that hydraulic oil leaks to the low pressure side.

  This invention is made in order to solve the said subject, and is equipped with the structure which can further suppress that a high pressure hydraulic fluid is accumulated between a 1st sealing material and a 2nd sealing material. It is to provide a sealing material.

  In the sealing material based on this invention, it is provided in the sliding gap between the cylinder and the rod in the hydraulic / pneumatic equipment, and is an annular partitioning the high pressure side and the low pressure side, which is placed in the seal groove provided in the cylinder. A sealing material body having an annular shape, a pressure accumulation preventing groove extending in a radial direction provided on the high pressure side of the sealing material body, and the pressure accumulation preventing groove on an outer peripheral side surface of the sealing material body And a pressure accumulating release groove having a form extending along the sliding direction of the rod.

  In another embodiment, the pressure accumulation prevention grooves are provided at four positions at a pitch of 90 degrees along the circumferential direction of the seal material body, and the pressure accumulation release grooves correspond to positions where the pressure accumulation prevention grooves are provided. And it is provided in four places with a 90-degree pitch along the outer peripheral surface direction of the said sealing material main body.

  In another embodiment, the low pressure side of the pressure accumulation opening groove is open on the lower surface of the seal material body.

  According to this sealing material, it is possible to provide a sealing material having a configuration capable of further suppressing the accumulation of high-pressure hydraulic oil between the first sealing material and the second sealing material. To do.

It is sectional drawing which shows the seal structure employ | adopted as the hydraulic equipment of embodiment. It is a perspective view of the sealing material of embodiment. It is a top view of the sealing material of embodiment. FIG. 4 is a partial enlarged view of a region surrounded by IV in FIG. 3. It is the elements on larger scale of the V direction arrow in FIG. It is a VI-VI direction arrow directional cross-sectional view in FIG. It is a figure which shows the groove shape of the pressure accumulation open | release groove | channel of embodiment. It is a figure which shows the groove shape of the pressure accumulation open | release groove | channel of another form. It is a figure which shows the groove shape of the pressure accumulation open | release groove | channel of another form.

  The sealing material in each embodiment based on the present invention will be described below with reference to the drawings. In each embodiment described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. The same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated. In the following, a hydraulic cylinder is cited as an example of a hydraulic / pneumatic device, but the present invention is not limited to a hydraulic cylinder, and can be widely applied to a hydraulic / pneumatic device.

(Seal structure)
With reference to FIG. 1, the seal structure in this Embodiment is demonstrated. FIG. 1 is a cross-sectional view showing a seal structure employed in the hydraulic cylinder in the embodiment. In FIG. 1, a cylinder 1 and a rod (piston rod) 2 are shown by broken lines for convenience of explanation. The seal structure shown in FIG. 1 is deformed with the pressure contact with the rod 2 and the reciprocating motion of the rod 2 (vertical direction in FIG. 1). However, in order to clearly understand the seal structure, pressure is applied to the seal structure. The state is not shown.

  An annular first seal groove 10 </ b> A is provided along the circumferential direction of the outer peripheral surface of the rod 2. The first seal material 100 that closes the sliding gap between the cylinder 1 and the rod 2 is accommodated in the first seal groove 10A. The first sealing material 100 constitutes a main sealing material.

  A second seal groove 20A is provided in an annular shape along the circumferential direction of the outer peripheral surface of the rod 2 and on the high-pressure side of the first seal groove 10A. In the figure, a high-pressure hydraulic chamber is provided on the upper side. The second seal groove 20 </ b> A accommodates a second seal material 200 that closes the sliding gap between the cylinder 1 and the rod 2. The second sealing material 200 constitutes an auxiliary sealing material.

  In the present embodiment, the same sealing material is used for the first sealing material 100 and the second sealing material 200. Hereinafter, the sealing material 100 is collectively referred to.

  In the present embodiment, a third seal groove 30A provided in an annular shape along the circumferential direction of the outer peripheral surface of the rod 2 is provided on the side opposite to the second seal groove 20A across the first seal groove 10A. ing. A third seal member 300 that closes the sliding gap between the cylinder 1 and the rod 2 is accommodated in the third seal groove 30A. The third sealing material 300 constitutes a dust sealing material for preventing dust from entering from the outside.

  In the figure, the side on which the upper hydraulic chamber is provided is the high pressure side, and the lower side is the low pressure side of the atmosphere. In this embodiment, a configuration in which a dust seal material is provided is employed.

(Sealant 100)
With reference to FIG. 2 to FIG. 7, the structure of the sealing material 100 of the present embodiment will be described. 2 is a perspective view of the sealing material 100, FIG. 3 is a plan view of the sealing material 100, FIG. 4 is a partially enlarged view of a region surrounded by IV in FIG. 3, and FIG. 6 is a partially enlarged view taken along the direction of the arrow, FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5, and FIG. 7 is a bottom view of the pressure accumulation opening groove 12.

  2 to 6, this sealing material 100 has an annular sealing material body 10 and has a substantially U-shaped cross-sectional shape having an open side on the high-pressure side. The sealing material main body 10 is integrally formed of synthetic resin such as urethane resin, natural rubber, or synthetic rubber.

  As clearly shown in the cross section of FIG. 6, the sealing material main body 10 includes an outer lip portion 10 a extending upward on the outer side and an inner lip portion 10 b extending upward on the inner side in a substantially U-shaped cross-sectional shape. The outer lip portion 10a is provided to be longer upward than the inner lip portion 10b.

  On the upper surface side (high pressure side) of the sealing material body 10, a pressure accumulation preventing groove 11 extending in the radial direction in plan view is provided. In the present embodiment, the pressure accumulation preventing grooves 11 are provided at four positions at a pitch of 90 degrees and at a pitch of 90 degrees along the circumferential direction.

  The pressure accumulation preventing groove 11 is provided so as to straddle the outer lip portion 10a and the inner lip portion 10b. The position and quantity of the pressure accumulation preventing groove 11 can be appropriately changed according to the required performance. The width L1 of the pressure accumulation preventing groove 11 is about 3 mm to 8 mm. The depth D1 of the pressure accumulation preventing groove 11 is about 0.3 mm to 0.8 mm.

  Referring to FIGS. 4 to 5, the outer circumferential side surface of the sealing material main body 10 has a pitch of 90 degrees along the outer circumferential surface direction of the sealing material main body 10 corresponding to the position where the pressure accumulation preventing groove 11 is provided. It is provided in the place. The position and quantity of the pressure accumulation opening groove 12 can be appropriately changed according to the required performance, but when provided, the pressure accumulation opening groove 12 is provided corresponding to the pressure accumulation preventing groove 11.

  The upper end of the pressure accumulating release groove 12 is provided such that a distance L4 from the lip tip R1 of the outer lip portion 10a extends along the sliding direction of the rod from a position of about 1 mm or more. It is provided so as to gradually become deeper downward from the tip. The distance L3 to the deepest position is about 1 mm to about 1.5 mm. Further, the width L2 is provided at about 1 mm to 2.5 mm.

  The lower end (low pressure side) of the pressure accumulation opening groove 12 is open on the lower surface of the seal material body 10. The depth L5 of the pressure accumulation opening groove 12 is about 0.5 mm to about 1.2 mm. A chamfered portion (C surface) of about 45 degrees is provided on the entire circumference of the corner portion of the lower surface of the sealing material body 10.

  As shown in FIG. 7, the shape of the pressure accumulation release groove 12 of the present embodiment has a semicircular shape.

  As described above, according to the sealing material body 10 in the present embodiment, the pressure accumulation release groove 12 is provided corresponding to the position where the pressure accumulation prevention groove 11 is provided. Thereby, for example, as shown in FIG. 1, in a situation where high-pressure hydraulic oil is accumulated between the first seal material and the second seal material, the outer peripheral surface side of each seal material is pressed against the bottom surface of the seal groove. Even in this situation, the pressure accumulation release groove 12 is provided in correspondence with the position where the pressure accumulation prevention groove 11 is provided, so that the hydraulic oil release route to the high pressure side becomes the pressure accumulation release groove 12 and the pressure accumulation. It is ensured by the prevention groove 11, and it is possible to further suppress the accumulation of high-pressure hydraulic oil between the first sealing material and the second sealing material.

  As a result, it is possible to prevent leakage of hydraulic oil to the low pressure side and realize a highly reliable seal structure.

  With reference to FIGS. 8 and 9, another shape of the pressure accumulation release groove 12 will be described. As shown in FIG. 7, the shape of the pressure accumulation release groove 12 of the present embodiment is a semicircular shape, but is not limited to this shape, and is trapezoidal as shown in FIG. The groove shape may be a rectangular groove shape as shown in FIG.

  Although the embodiments of the present invention have been described above, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 cylinder, 2 rod, 10 seal material, 10A first seal groove, 10a outer lip portion, 10b inner lip portion, 11 pressure accumulation prevention groove, 12 pressure accumulation release groove, 20A second seal groove, 300 dust seal material (third seal material ), 30A third seal groove, 100 main seal material (first seal material), 200 auxiliary seal material (second seal material).

Claims (3)

An annular sealing material that is provided in a sliding gap between a cylinder and a rod in a hydraulic / pneumatic device and is placed in a sealing groove provided in the cylinder, which partitions a high-pressure side and a low-pressure side,
An annular seal body,
A pressure accumulation preventing groove provided on the high pressure side of the sealing material body and extending in a radial direction;
On the outer peripheral side surface of the seal material main body, a pressure accumulation release groove is provided at a position corresponding to the pressure accumulation prevention groove, and has a form extending along the sliding direction of the rod;
A sealing material. The pressure accumulation prevention grooves are provided at four locations at a pitch of 90 degrees along the circumferential direction of the seal material body,
2. The seal according to claim 1, wherein the pressure accumulation release grooves are provided at four positions at a pitch of 90 degrees along the outer peripheral surface direction of the seal material main body corresponding to a position where the pressure accumulation prevention groove is provided. Wood.   The sealing material according to claim 1 or 2, wherein a low-pressure side of the pressure accumulation opening groove is open on a lower surface of the sealing material body.

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