JP2021050754A - gasket - Google Patents

Abstract

To provide a gasket that has sufficient pressure resistance and has low cost.SOLUTION: A gasket 1 that is mounted between two members in which a fluid flow path is formed to prevent pressure fluid from leaking from a gap between the two members, is composed of a rubber material with a rubber hardness of 70 degrees or more and 100 degrees or less; is provided with a chamfer 7 on an outer peripheral part 3 of both end surfaces 2 of the two members that come into contact with a surface (seal surface) orthogonal to the fluid flow path of a mating member; and take a substantially U-shaped cross-sectional shape with a recess part 5 provided at the center of an inner peripheral surface.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gasket used by being mounted between two members in which a flow path of a pressure fluid is formed in various devices using a pressure fluid. More specifically, the present invention relates to gaskets that are particularly useful for sealing hydraulic equipment.

For example, in a hydraulic device, as shown in FIG. 4, two members 101 and 102 are on the mating surface (inside of the seal housing 104) of the oil passages of one member 101 and the other member 102 each having an oil passage 105. The gasket 106 is attached so that the hydraulic oil does not leak from the gap 103 between them. In this kind of application, the gasket 106 is required not to cause deformation that affects the function even when a maximum hydraulic pressure of about 5 MPa is applied, and to prevent abnormal deformation of the lip due to the hydraulic pressure. For this reason, a rubber lip reinforced with a metal ring 107 as shown in FIG. 3 is used.

However, by providing the metal ring, the unit price of the metal ring, the unit price of the adhesive, the management cost of the metal ring and the adhesive, the complexity of the mold structure for gasket molding, and the increase in the molding manpower (adhesive application, incorporation of the metal ring). , There is a problem that the cost increases due to an increase in inspection points and an increase in the number of defects (adhesive defects). In addition, there is a problem that the weight is increased by the metal ring.

In order to solve such a problem, it is conceivable to use an O-ring, a D-ring, or a lip packing without a metal ring. However, in the case of O-rings and D-rings, since the volume of rubber is large, there is a risk of protrusion to the oil passage side when the rubber is mounted between the two members and crushed, and the gap between the two members varies. However, it is necessary to increase the crushing rate, but there is a risk that the reaction force will be excessive and the durability of the gasket and the assembling property of the hydraulic equipment will be affected. In particular, it becomes a big problem when the variation of the gap between the two members is large. Further, since it does not have a lip, the effect of improving the sealing property (self-sealing) by flood control cannot be obtained, and the crushing rate must be increased in order to improve the sealing property.

Further, in the case of lip packing such as V packing, it is generally for non-pressure to low pressure, and has a delicate structure as a whole with a thin lip thickness in consideration of assembling property, followability, self-sealing property, etc. , Rubber is also used with a hardness of about 60 degrees. Therefore, when it is used for a flood control device, there are problems of damage due to deformation of the entire lip packing and the lip, deterioration of durability, and deterioration of sealing property. Further, it is conceivable to stack a plurality of lip packings in order to have pressure resistance, or to attach a backup ring to the lip packings, but all of them are factors of cost increase.

An object of the present invention is to provide a gasket having sufficient pressure resistance and low cost.

A gasket for achieving such an object is a gasket that is mounted between two members in which a fluid flow path is formed inside and prevents pressure fluid from leaking from a gap between the two members, and has rubber hardness. Is made of a rubber material of 70 degrees or more and 100 degrees or less, and chamfers are provided at the corners of both end surfaces and the outer peripheral portion that come into contact with the sealing surfaces of the two members, and a recess is provided in the center of the inner peripheral surface. It is designed to be formed in a vertical cross-sectional shape.

Here, the vertical cross section of the gasket preferably has a ratio of the vertical width dimension to the horizontal thickness dimension in the range of 1.3 to 2: 1.

Further, in the vertical cross section of the gasket, the depth of the recess is preferably 25 to 45% of the horizontal thickness dimension.

Further, in the vertical cross section of the gasket, it is preferable that the concave portion is tapered and the opening width is 30 to 50% of the vertical width dimension.

Further, it is preferable that the vertical cross section of the gasket is provided with flat portions on both end surfaces that come into contact with the mating member when mounted on the mating member, so that the outer diameter of the flat portion is larger than the outer diameter of the recess.

Further, it is preferable that the dimension of the flat portion in the vertical cross-sectional shape is 35 to 50% of the lateral thickness dimension.

According to the gasket according to claim 1, since the gasket is made of a rubber material having a rubber hardness of 70 degrees or more and 100 degrees or less, even if the rigidity of the gasket is increased and pressure is applied, the gasket is deformed in the outer diameter direction, and between the two members. It is possible to suppress the protrusion of the rubber into the gap. In addition, deformation of the lip formed by the chamfer and the recess can be suppressed.

Therefore, it is possible to provide sufficient pressure resistance even though the metal ring is not used, and it is expected that the cost can be cut by not using the metal ring. That is, it is possible to realize a gasket having sufficient pressure resistance and suppressing the cost.

Further, by chamfering the corners between both end surfaces of the gasket and the outer peripheral portion, the contact area with the mating member does not become excessive and good contact pressure is maintained, and when pressure is applied, both end surfaces are provided. Can make strong contact with the mating member on the surface. Therefore, even if the end face of the gasket tries to be inverted, the resistance is increased and the inversion can be prevented. Further, since the volume of the rubber is reduced by the amount of chamfering of the gasket, even if pressure is applied and the gasket is deformed in the outer diameter direction, the deformation does not reach the gap between the two members.

In addition, a recess is provided in the center of the inner peripheral surface of the gasket so that the arm portion around the recess is bent in the direction of expanding the recess when pressure is applied, so that both end surfaces are strongly pressed against the mating member. The sealing property can be improved.

Furthermore, by forming the gasket in the shape of an abbreviation in cross section by chamfering and recessing, the gasket is easily crushed against the size of the gap due to variations during assembly of the two members, and fluctuations in contact pressure are suppressed. can do.

Further, according to the gasket according to claim 2, by setting the cross-sectional dimension aspect ratio of the gasket to 1.3 to 2: 1, the amount of crushing with respect to the crushing allowance when mounted between the mating members is made appropriate. It is possible to maintain the sealing performance, improve the durability of the gasket, and improve the assembling property of the hydraulic equipment. In addition, the length of the arm portions on both end surfaces of the gasket formed by the recesses becomes relatively long, and when pressure is applied, the arm portions are strongly pressed by the mating member to improve the sealing property (self). sticker).

Further, according to the gasket according to claim 3, by setting the depth of the recess to 25 to 45% of the cross-sectional thickness (horizontal) dimension of the gasket, the length of the arm portions on both end faces of the gasket is secured and the pressure is increased. When added, the arm portion is strongly pressed by the mating member to improve the sealing property (self-sealing). In addition, it has sufficient rigidity to maintain the shape of the gasket, and the amount of crushing required for the gasket can be surely secured.

Further, according to the gasket according to claim 4, by tapering the concave portion, the tip end side of the arm portion becomes thin and the contact pressure with the mating member increases when pressure is applied, so that the sealing property can be improved. Further, by setting the opening width to 30 to 50% of the cross-sectional width (vertical) dimension of the gasket, a sufficient wall thickness of the arm portion on both end surfaces of the gasket is secured, and the arm portion is deformed when pressure is applied. It is difficult to prevent inversion.

Further, according to the gasket according to claim 5, flat portions that come into contact with the mating member when mounted on the mating member are provided on both end faces of the gasket, and the outer diameter of the flat portion is made larger than the outer diameter of the recess. , The amount of crushing required for the gasket can be reliably secured.

Further, according to the gasket according to claim 6, by setting the plane portion dimension in the cross-sectional shape of the gasket to 35 to 50% of the cross-sectional thickness (horizontal) dimension of the gasket, the contact area with the mating member becomes excessive. Not too much, good contact pressure is maintained, and when pressure is applied, both end faces come into strong contact with the mating member, so even if the gasket end face tries to reverse, resistance increases and the effect of preventing reverse rotation is further enhanced.

It is a central vertical sectional view which shows one Embodiment of the gasket which concerns on this invention. It is explanatory drawing which shows the state in which the gasket is used. It is a central vertical sectional view showing an example of a conventional gasket, and only half is shown. It is explanatory drawing which shows the use example of the conventional gasket.

Hereinafter, the configuration of the present invention will be described in detail based on the embodiments shown in the drawings.

FIG. 1 shows an example of an embodiment of the gasket of the present invention. As shown in FIG. 2, the gasket 1 according to this embodiment is a two member (in the present specification) in which a flow path 16 of a pressure fluid is formed inside in various devices using a pressure fluid, particularly a hydraulic device. It is mounted between the mating members 10 and 11) to prevent the pressure fluid from leaking from the gap 12 between the two members (the mating members 10 and 11). The gasket 1 is housed in a seal housing 13 formed on at least one of the two members, for example, the mating member 11, and the outer peripheral portion 3 of the gasket 1 is radially received by the peripheral wall portion 17 of the seal housing 13. While being supported, both end faces 2 in the axial direction are sandwiched between the sealing surfaces 14 and 15 of the mating members 10 and 11, respectively, and are provided so as to seal between the two members (corresponding members 10 and 11).

Here, the gasket 1 according to the present embodiment is made of a rubber material, and has both end surfaces 2 in contact with the sealing surfaces 14 and 15 of the mating members 10 and 11 and an outer peripheral portion 3 in contact with the peripheral wall portion 17 of the seal housing 13. A chamfer 7 with an angle between the two is provided, and a recess 5 is provided in the center of the inner peripheral surface to form a substantially oval cross-sectional shape.

Specifically, the gasket 1 of the present embodiment has an annular shape as shown in FIG. 1, for example, and both end surfaces 2 in the axial direction come into contact with the sealing surfaces 14 and 15 of the mating members 10 and 11 to form a seal. Is what you do. Therefore, at least both end surfaces 2 are provided with flat surface portions 6 that come into contact with the sealing surfaces 14 and 15 of the mating members 10 and 11. Further, on the inner peripheral surface side of the gasket 1, a recess 5 is provided in the center of the inner peripheral surface, and a lip 9 is formed at an angle between the inner peripheral surface 4 and the end surface 2. On the other hand, on the outer peripheral surface side of the gasket 1, a outer peripheral portion 3 and a chamfer 7 having a corner between the end surface 2 and the outer peripheral portion 3 are formed. The gasket 1 formed by the chamfer 7 and the recess 5 in a substantially shape of a cross section is configured with an arm portion 8 that applies an elastic force that presses the end surface 2 against the sealing surfaces 14 and 15 of the mating members 10 and 11. The gasket 1 is easily crushed with respect to the size of the gap 12 due to variations in the assembly of the mating members 10 and 11, so that fluctuations in contact pressure can be suppressed. Further, when pressure is applied from the flow path 16 side, the lip 9 and the end surface 2 are bent by bending the arm portion 8 around the recess 5 in the direction of expanding the recess 5 provided in the center of the inner peripheral surface of the gasket 1. The sealing property can be improved by strongly pressing against the contact surfaces 14 and 15 of the mating members 10 and 11. Here, in the present embodiment, the gasket 1 is formed symmetrically in the axial direction (vertical direction in FIG. 1), but it is not necessary to consider the orientation when mounting the gasket 1, and workability can be improved. it can. In the case of the present embodiment, the arm portion 8 refers to a region on the end surface 2 side of the line segment A connecting the bottom portion of the recess and the edge of the chamfer 7 on the outer peripheral portion 3 side.

The rubber material used for the gasket 1 is not particularly limited, and any rubber generally used as a sealing material such as nitrile rubber, acrylic rubber, and silicone rubber can be selected according to the usage conditions.

Further, as the rubber material, a rubber material having a rubber hardness of 70 degrees or more and 100 degrees or less is used. If the gasket 1 is made of a rubber material within this rubber hardness range, the rigidity of the gasket 1 is increased, and even if pressure is applied, the gasket 1 is deformed in the outer diameter direction, and the gap 12 between the mating members 10 and 11 is reached. It is possible to suppress the protrusion of rubber. In addition, deformation of the lip 9 can be suppressed. On the other hand, if the hardness is less than 70 degrees, there is a difficulty in shape retention under conditions such as when a maximum hydraulic pressure of about 5 MPa is applied, and there is a risk that it becomes necessary to use an auxiliary member such as a reinforcing ring. It is more preferable that the rubber hardness is 90 degrees or more in order to more reliably suppress the deformation of the gasket 1. Further, if it exceeds 100 degrees, it is too hard to be sufficiently adhered to the mating sealing surfaces 14 and 15, and the sealing property is deteriorated, or the reaction force becomes too high when it is mounted between the mating members 10 and 11. There is a risk of affecting the durability of the gasket and the assembling property of the flood control equipment.

The size of the chamfer 7 is appropriately determined in consideration of, for example, the usage conditions and the balance with other parts of the gasket, but the contact area with the mating members 10 and 11 does not become excessive and a good contact pressure is maintained. At the same time, it is preferable that both end faces 2 come into strong contact with the mating members 10 and 11 when pressure is applied, so that even if the gasket end faces 2 try to reverse, the resistance increases and the inversion can be prevented. Since the volume of the rubber is reduced by the amount of the corners removed by the chamfer 7, even if pressure is applied and the gasket 1 is deformed in the outer diameter direction, the gap 12 between the mating members 10 and 11 is not deformed. .. Further, by removing the corners, the arm portion 8 can be easily deformed.

Here, the cross-sectional dimension aspect ratio of the gasket 1 (that is, the vertical cross-sectional dimension V: the cross-sectional dimension H) is preferably in the range of 1.3 to 2: 1. By setting the cross-sectional dimension aspect ratio V: H of the gasket 1 to be in the range of 1.3 to 2: 1, the amount of crushing with respect to the crushing allowance when mounted between the mating members 10 and 11 can be made appropriate. It is possible to maintain the sealing property, improve the durability of the gasket 1, and improve the assembling property of the flood control device. Further, the length of the arm portion 8 on both end faces 2 of the gasket formed by the recess 5 becomes relatively long, and the arm portion 8 is pressed more strongly against the mating members 10 and 11 when pressure is applied. The sealing property can be improved (self-sealing). On the other hand, if the vertical dimension V is less than 1.3 times the horizontal dimension H, the crushing amount (crushing rate) with respect to the crushing allowance becomes too large, and the gasket 1 is damaged due to abnormal deformation and protrusion, and the surface pressure due to sagging. There is a risk of deterioration (deterioration of sealing performance) and deterioration of assembly workability of hydraulic equipment. Further, when the vertical dimension V exceeds twice the horizontal dimension H, the gasket 1 tends to buckle, a sufficient surface pressure cannot be obtained, and the arm portions 8 of the gasket end surface 2 formed by the recesses 5 There is a risk that the length will be relatively short, the self-sealing effect will be small, and the sealing performance will deteriorate.

Further, the depth D of the recess 5 is preferably 25 to 45% of the cross-sectional thickness (horizontal) dimension H of the gasket 1. In this case, when the length of the arm portion 8 on both end surfaces 2 of the gasket is secured and pressure is applied, the arm portion 8 is strongly pressed by the sealing surfaces 14 and 15 of the mating members 10 and 11 to improve the sealing property. Can be (self-sealing). In addition, it has sufficient rigidity to maintain the shape of the gasket 1, and the amount of crushing required for the gasket 1 can be surely secured. On the other hand, if the depth D of the recess 5 is less than 25% of the cross-sectional thickness H, the length of the arm portion 8 on both end faces 2 of the gasket becomes too short, and there is a risk that the self-sealing effect is small and the sealing property is deteriorated. .. Further, the repulsive force when crushing the gasket 1 becomes too high, and there is a risk that the surface pressure is lowered due to sagging (deterioration of sealing property) and the workability of assembling the hydraulic device is deteriorated. Further, if the depth D of the recess exceeds 45% of the cross-sectional thickness (horizontal) dimension of the gasket, there is a risk that the arm portion 8 will be inverted when the arm portion 8 becomes too long and pressure is applied. In addition, the gasket 1 is easily crushed, and there is a risk that a sufficient crushing amount cannot be secured.

Here, it is preferable that the recess 5 has a tapered shape as shown in FIG. In this case, the tip end side of the arm portion 8 of the gasket end surface 2 formed by the recess 5 becomes thin, and when pressure is applied, the contact pressure with the mating members 10 and 11 becomes high, and the sealing property can be improved. However, the shape of the recess 5 does not necessarily have to be tapered, and in some cases, a groove having the same width in the depth direction where the bottom is flat, or a curved surface shape in which the width becomes wider toward the inside than the entrance portion, or a mere half. It may be circular or V-shaped with a sharp wedge shape. In any case, it is sufficient if the length of the arm portion 8 of the gasket end surface 2 formed by the recess 5 is sufficient.

Further, the opening width W of the recess 5 is preferably 30 to 50% of the cross-sectional width (vertical) dimension V of the gasket 1. In this case, it is possible to secure a sufficient wall thickness of the arm portion 8 on both end faces 2 of the gasket to make it difficult for the arm portion 8 to be deformed when pressure is applied and to prevent inversion. On the other hand, if the opening width W of the recess 5 is less than 30% of the cross-sectional width dimension V of the gasket 1, the volume of the gasket 1 becomes high and the amount of crushing becomes too large, resulting in abnormal deformation, damage to the gasket 1 due to protrusion, and sagging. There is a risk of reduced surface pressure (deterioration of sealing performance) and deterioration of assembly workability of hydraulic equipment. Further, there is a risk that the rigidity of the arm portion 8 becomes too high and the self-sealing effect can hardly be exhibited. Further, if the opening width W of the recess 5 exceeds 50% of the cross-sectional width dimension V of the gasket 1, the wall thickness of the arm portion 8 cannot be sufficiently secured, and the arm portion 8 is abnormally deformed when pressure is applied. There is a risk that the gasket 1 will be damaged due to the protrusion 12 into the gap 12 between the mating members 10 and 11, and that the arm portion 8 will be inverted and the seal will be defective.

Here, the end surface 2 of the gasket 1 is provided with a flat surface portion 6 that comes into contact with the sealing surfaces 14 and 15 of the mating members 10 and 11 when mounted. The outer diameter of the flat surface portion 6 is preferably larger than the outer diameter of the recess. In this case, a rubber portion continuous in the crushing direction of the gasket is formed, and the crushing amount required for the gasket can be surely secured.

Further, the radial length of the flat surface portion 6 (hereinafter referred to as the flat surface portion dimension L) is preferably 35 to 50% of the thickness (horizontal) dimension H of the gasket 1. In this case, the contact area with the mating member does not become excessive and a good contact pressure is maintained, and when the pressure is applied, both end faces 2 make strong contact with the mating members 10 and 11 so that the gasket end face is formed. Even if an attempt is made to invert, the resistance increases and the inversion can be prevented. Further, since the rigidity required for the arm portion 8 is obtained, abnormal deformation and protrusion into the gap 12 are prevented, and the risk of damage is reduced. On the other hand, if the flat surface dimension L is less than 35% of the thickness (horizontal) dimension H of the gasket 1, the volume of the arm portion 8 becomes small, and the arm portion 8 is abnormally deformed when pressure is applied. There is a risk that the gasket 1 will be damaged due to the protrusion into the gap 12 between the mating members 10 and 11, and that the arm portion 8 will be inverted and the seal will be defective. On the other hand, if it exceeds 50%, the volume of the arm portion 8 becomes too large, and there is a risk of damage to the gasket 1 due to abnormal deformation and protrusion.

According to the gasket 1 configured as described above, when the gasket 1 is housed in the seal housing 13 of one of the mating members and mounted between the two members 10 and 11, the outer peripheral portion 3 of the gasket 1 is the peripheral wall portion of the seal housing 13. 17 is supported in the radial direction, and both end surfaces 2 in the axial direction are sandwiched between the sealing surfaces 14 and 15 of the mating members 10 and 11, respectively, and the arm portion 8 is bent while being sandwiched between the two members (corresponding members 10 and 11). To seal. Moreover, since the gasket 1 is made of a rubber material having a rubber hardness of 70 degrees or more and 100 degrees or less, the rigidity of the gasket 1 is increased even if the metal ring is not embedded, and even if pressure is applied, the outside of the gasket 1 It is possible to suppress deformation in the radial direction and protrusion of the mating members 10 and 11 into the gap 12. Further, since the deformation of the lip 9 can be suppressed, the pressure fluid does not leak from the gap 12.

Further, by bending the arm portion 8 by expanding the recess 5 by the pressure of the fluid applied to the gasket 1, both end surfaces 2 can be strongly pressed against the mating members 10 and 11 to improve the sealing property.

The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be performed without departing from the gist of the present invention. For example, in the above-described embodiment, the cross-sectional shape of the gasket 1 is abbreviated by the chamfer 7 and the recess 5, but the shape is not particularly limited to this, and is not particularly limited to the bow shape, U shape, C shape,> shape, and the like. The shape is not limited to a specific shape as long as it has a similar shape, that is, a shape having an arm portion that deforms so that the end face 2 is pressed against the two members under pressure.

1 Gasket 2 End face 3 Outer circumference 4 Inner peripheral surface 5 Recess 6 Flat part 7 Chamfer 8 Arm part V Vertical width Dimension H Width thickness Dimension D Recess depth W Recess opening width L Flat part Dimension 10 One mating member 11 Opposite member 12 Gap between two members 13 Seal housing 14, 15 Seal surface 16 Flow path 17 Outer peripheral surface of seal housing

Claims (6)

A gasket that is mounted between two members in which a fluid flow path is formed to prevent pressure fluid from leaking from the gap between the two members.
It is made of a rubber material with a rubber hardness of 70 degrees or more and 100 degrees or less.
In addition, chamfers are provided at the corners of both end faces and the outer peripheral portion that come into contact with the sealing surfaces of the two members, and a recess is provided in the center of the inner peripheral surface to form an abbreviated vertical cross-sectional shape. Gasket to do. The gasket according to claim 1, wherein the ratio of the vertical width dimension to the horizontal thickness dimension is in the range of 1.3 to 2: 1 in the vertical cross section. The pressure-resistant gasket according to claim 1 or 2, wherein the depth of the recess in the vertical cross section is 25 to 45% of the lateral thickness dimension. The gasket according to any one of claims 1 to 3, wherein in the vertical cross section, the concave portion is tapered and the opening width W is 30 to 50% of the vertical width dimension. Any of claims 1 to 4, wherein a flat surface portion that comes into contact with the mating member when mounted on the mating member is provided on both end surfaces, and the outer diameter of the flat surface portion is made larger than the outer diameter of the recess. The gasket described in one. The gasket according to claim 5, wherein the dimension L of the flat surface portion in the vertical cross-sectional shape is 35 to 50% of the lateral thickness dimension.

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