JP6399471B2 - SEALING DEVICE AND MANUFACTURING METHOD THEREOF - Google Patents

Description

  The present invention relates to a sealing device and a manufacturing method thereof.

  Conventionally, a sealing device has been used to seal a gap between two members that rotate relative to each other in transportation equipment, industrial equipment, household equipment, and the like. FIG. 6 is a cross-sectional view showing the structure of this type of conventional sealing device.

  As shown in FIG. 6, the conventional sealing device 100 is, for example, a casing 101 that is a mounted portion of the sealing device 100 that is one of two members that rotate relative to each other, and is the other of the two members. The space between the shafts 102 is sealed. Specifically, the sealing device 100 is disposed in an annular gap 104 between the shaft hole 103 of the casing 101 and the shaft 102 inserted through the shaft hole 103, and seals the gap 104. . The sealing device 100 has an annular shape centering on an axis, and includes an annular reinforcing ring 105 and a main body 106 made of a rubber material integrally formed so as to cover the reinforcing ring 105. The main body 106 has a mounting portion 107 on the outer peripheral side and a seal portion 108 on the inner peripheral side. The sealing device 100 is attached to the casing 101 with an attachment portion 107 fitted in the shaft hole 102. The outer peripheral surface 107 a of the attachment portion 107 is in close contact with the peripheral surface of the shaft hole 102. Further, the seal portion 108 includes a seal lip portion 109 extending in the inner peripheral direction, and the seal lip portion 109 includes a lip tip portion 110 having a wedge-shaped cross section that protrudes in the axial direction at the inner peripheral side end portion. The lip tip 110 is defined by an inner inner surface 110 a and an outer outer surface 110 b, and is in liquid-tight contact with the peripheral surface of the shaft 102.

  The seal lip 109 has an annular recess 111 on the outer surface facing the lip tip 110, and an annular spring 112 is accommodated in the recess 111. Further, as shown in FIG. 6, the inner end face 115 of the seal lip 109 is provided with a turn-up preventing protrusion 113 which is an annular protrusion protruding in the inner direction. The turn-up preventing protrusion 113 prevents the seal lip 109 from being deformed inward and turned inward when the shaft 102 is inserted into the sealing device 100 during assembly (see, for example, Patent Document 1). ).

  That is, when the shaft 102 and the sealing device 100 are misaligned when the shaft 102 is inserted into the sealing device 100, the lip tip 110 is caught on the surface of the shaft 102, and the shaft 102 is further inserted. The seal lip portion 109 tries to turn over in the inner circumferential direction. At this time, the turn-up preventing projection 113 is brought into contact with the surface of the shaft 102 to prevent the seal lip portion 109 from turning up further in the inner peripheral side direction.

  Further, in a conventional sealing device, after molding using a molding die, a lip end portion is formed by cutting a waste portion with a knife, thereby forming a main body (see, for example, Patent Document 2). By forming the lip tip portion with a knife cut, the lip tip portion can be formed smoothly, and the sealing performance of the sealing device can be improved as compared with the case of molding.

Japanese Utility Model Publication No. 04-11968 JP 2006-292160 A

  However, as will be described later, in the conventional sealing device having the anti-flipping projection, when the lip tip portion is formed with a knife cut, a sufficient anti-flipping effect by the anti-flipping projection cannot be obtained.

  FIG. 7 is a view for explaining a knife cutting process when the lip tip 110 is formed by knife cutting in the sealing device 100. As shown in FIG. 7, after molding, the main body 106 is formed in a state in which the fillet portion 114 is provided inside the lip tip portion 110. Next, the cut portion 114 is cut by a knife cut, and the inner side surface 110a of the lip tip portion 110 is formed. The anti-flipping projection 113 is formed by molding. When the knife is cut, the anti-flipping projection 113 is arranged so that the anti-flipping projection 113 is removed from the knife cutting track so that the anti-flipping projection 113 is not cut off or damaged. Must. For this reason, on the inner end surface 115 of the seal lip portion 109, the turn-up preventing projection 113 is positioned in the vicinity of the connection portion 116 between the inner side surface 110a of the lip tip portion 110 and the inner end surface 115 and above.

  When the sealing device 100 is assembled, the lip tip 110 may be caught on the surface of the shaft 102 when the shaft 102 is inserted into the sealing device 100. When the lip tip 110 is caught on the surface of the shaft 102, the seal lip 109 is deformed in the direction of the shaft 102. Then, the connecting portion 116 is caught on the shaft 102, and the turn-up preventing protrusion 113 contacts the shaft 102. When the turn-up preventing projection 113 comes into contact with the shaft 102, a force for preventing the seal lip 109 from turning up (hereinafter also referred to as a turn-up preventing force) is generated.

  However, in the conventional sealing device 100 in which the lip tip portion 110 is formed by the knife cut, as shown in FIG. 7, the portion of the seal lip portion 109 that is hooked with the shaft 102 (connection portion 116) and the turn-up preventing protrusion 113. The spacing between the two is narrow and the anti-turning force exerted by the anti-turning protrusion 113 is weak, so that sufficient anti-turning action cannot be obtained. Further, when the anti-flipping projection 113 is disposed away from the connection portion 116, the anti-flipping projection 113 may not contact the shaft 102 even if the seal lip 109 is deformed, or the anti-flipping projection 113 is Even if it abuts on the shaft 102, the spring 112 may be detached from the recess 111 due to a large deformation of the seal lip 109. For this reason, in the conventional sealing device 100, the turn-up preventing protrusion 113 cannot be disposed away from the connection portion 116.

  Thus, in the conventional sealing device 100, the space between the connecting portion 116 as a fulcrum for the anti-turning force and the anti-turning protrusion 113 is narrow, and the anti-turning force exerted by the anti-turning protrusion 113 is weak and sufficient. The curling prevention action could not be obtained. For this reason, the seal lip 109 may be turned over, and even if the seal lip 109 is not finally turned over, the spring 112 is detached from the recess 111 due to a large deformation of the seal lip 109. There was a case.

  In order to solve the above-described problems, an object of the present invention is to provide a sealing device capable of improving the force to prevent the seal lip portion from turning over when the other of the two members that rotate relative to each other is inserted. And a manufacturing method thereof.

  In order to achieve the above object, according to the sealing device of the present invention, a sealing device for sealing a gap between two members that can rotate relative to each other with respect to an axis, the main body made of an elastic body, and the axis An annular spring having a center, and the main body is fitted to a mounted portion which is one of the two members, and is slid on the other of the two members. A seal portion that is intimately contactable, and the seal portion includes an annular seal lip portion centered on the axis, and the seal lip portion is an annular ridge projecting toward the axis. And an annular recess centered on the axis provided opposite to the tip of the lip, the spring being accommodated in the recess, and the end of the seal lip portion on the sealed object side An annular ridge that protrudes toward the sealed object side at the part In the sealing device provided with the anti-flipping projection, the lip tip portion includes, in order from the sealing object side, a first surface, a second surface, and a third surface. The surface is a tapered surface whose diameter decreases from the sealed object side toward the side opposite to the sealed object side, and the second surface extends from the sealed object side to the side opposite to the sealed object side. The third surface is a tapered surface that decreases in diameter toward the sealing object, and the third surface is a tapered surface that increases in diameter from the sealing object side toward the side opposite to the sealing object side.

  In the sealing device according to one aspect of the present invention, the connection portion between the first surface and the second surface is convex toward the axis.

  In the sealing device according to an aspect of the present invention, the first surface of the lip tip is connected to the turn-up preventing protrusion.

  In the sealing device according to one aspect of the present invention, the connection portion between the second surface and the third surface is slidably in close contact with the other of the two members.

  In the sealing device according to an aspect of the present invention, the seal portion includes a first spring drop-off preventing protrusion that is an annular protrusion projecting from an edge of the recess opposite to the object to be sealed. And a second spring drop-off preventing protrusion that is an annular protrusion protruding from the edge of the concave portion on the sealed object side.

  The sealing apparatus which concerns on 1 aspect of this invention WHEREIN: The said 1st spring drop-off prevention protrusion is diameter-expanded as it goes to the said sealing target object side.

  The sealing device according to an aspect of the present invention includes an annular reinforcing ring centering on the axis, and the reinforcing ring is covered at least partially by the main body.

  In order to achieve the above object, a method of manufacturing a sealing device according to the present invention is the method of manufacturing a sealing device according to any one of claims 1 to 7, wherein the first surface and the third surface. After forming the lip, the second surface is formed by a knife cut to form the lip tip.

  In the manufacturing method of the sealing device according to an aspect of the present invention, the first surface and the third surface have an excess sunk portion between the first surface and the third surface, It shape | molds and the said 2nd surface is shape | molded by carrying out the scalpel cutting of the said surplus part.

  According to the sealing device of the present invention, the lip tip portion includes the first surface and the second surface on the inner surface, and the first surface is directed from the sealed object side to the side opposite to the sealed object side. Therefore, even when the second surface of the lip tip portion is formed by a knife cut, the turn-up preventing protrusion is more than the conventional one from the connecting portion between the first surface and the second surface. Can also be located at remote locations. For this reason, when the other of the two members rotating relative to each other is inserted into the sealing device, the connection portion between the first surface and the second surface of the lip tip is caught on the other surface of the two members. Even so, the turn-up preventing projection can be located at a position farther away from the hooked portion of the lip tip. For this reason, the force which prevents the turning-off prevention protrusion from being turned over can be made stronger than before, and the force which prevents the seal lip portion from turning up can be improved. In addition, this can prevent the spring from falling off from the recess.

  According to the sealing device according to the present invention, the connection portion between the first surface and the second surface is convex toward the axial line side, so that the second surface can be easily manufactured by female cutting. Can do.

  According to the sealing device according to the present invention, since the first surface is connected to the anti-flipping projection, when the two members are inserted into the other sealing device, there is a possibility of being caught by the other of the two members. A portion of a certain seal lip portion does not come closer to the turn-up preventing projection than the connection portion between the first surface and the second surface. For this reason, it is possible to make the effect of improving the anti-turning force produced by the structure of the first surface more effective.

  According to the sealing device according to the present invention, the first spring drop-off preventing projection that is an annular ridge is provided on the edge of the concave portion in which the spring is accommodated on the side opposite to the object to be sealed, Since the second spring drop-off preventing protrusion, which is an annular ridge, protrudes from the edge of the concave portion on the sealing object side, even when the seal lip portion is deformed, the spring is prevented from dropping out of the concave portion. be able to.

  According to the sealing device of the present invention, since the first spring drop-off preventing projection is enlarged toward the object to be sealed, it is possible to more reliably prevent the spring from dropping from the concave portion.

  According to the manufacturing method of the sealing device according to the present invention, since the second surface is formed with a knife cut after the first surface and the third surface are formed, the second surface is formed with the knife cut. In addition, the second surface can be easily molded without the turning-up preventing projection being in the way. This can also prevent the turn-up preventing protrusion from being damaged during manufacture.

  According to the manufacturing method of the sealing device according to the present invention, the first surface and the third surface are molded with an excess surplus portion between the first surface and the third surface, and then, Since the second surface is formed by cutting the waste meat portion with a knife, manufacturing of the lip tip portion can be facilitated.

It is sectional drawing in the cross section along the axis line of the sealing device which shows schematic structure of the sealing device which concerns on embodiment of this invention. It is a fragmentary sectional view for showing the use condition of the sealing device concerning the above-mentioned embodiment of the present invention. It is a figure for showing the state which has inserted the shaft in the sealing device in order to make it the use condition of the above-mentioned FIG. It is the elements on larger scale of the sealing device shown in FIG. It is a figure for showing roughly a formation process of a lip tip part in a manufacturing method of a sealing device concerning an embodiment of the invention. It is sectional drawing for showing the structure of the conventional sealing device. It is a figure for demonstrating the knife cutting process at the time of shape | molding a lip front-end | tip part by knife cutting in the sealing device shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view taken along the axis of the sealing device, showing a schematic configuration of the sealing device according to the embodiment of the present invention.

  As shown in FIG. 1, a sealing device 1 according to an embodiment of the present invention includes a main body 2 made of an annular elastic body centered on an axis x and a reinforcing ring 3 made of an annular metal centered on the axis x. With. Examples of the elastic body of the main body 2 include various rubber materials such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM). is there. Examples of the metal of the reinforcing ring 3 include stainless steel and SPCC (cold rolled steel). The sealing device 1 seals a gap between two members that can rotate relative to each other about an axis.

  The main body 2 includes a mounting portion 4 fitted into an opening of a mounting portion such as a casing or a housing as one of the two members that can rotate relative to each other, and the other of the two members inserted through the main body 2, for example, And a seal portion 5 slidably in close contact with the outer peripheral surface of the shaft.

  The attachment portion 4 is a cylindrical annular portion centering on the axis line x on the outer peripheral side in the main body 2. An outer peripheral surface 41 which is a peripheral surface on the outer peripheral side of the attachment portion 4 is defined based on a fastening margin portion 42 having a thickness (a radial dimension) corresponding to the size of the opening of the attached portion (not shown). Here, for convenience of explanation, the outer side is the arrow a (see FIG. 1) direction in the axis x direction, and the inner side is the arrow b (see FIG. 1) direction in the axis x direction. That is, the inside is the direction (sealing object side) facing the region where the sealing object such as lubricating oil is present in use, and the outside is the absence of the sealing object or the presence of the sealing object. It is the direction (the side opposite to the object to be sealed) facing the region that is not allowed to be made. Further, in the direction perpendicular to the axis x, the direction away from the axis x (the direction of arrow c in FIG. 1) is the outer peripheral side, and the direction approaching the axis x (the direction of arrow d in FIG. 1) is the inner peripheral side.

  The seal portion 5 is a cylindrical annular portion centering on the axis line x on the inner peripheral side in the main body 2 and includes a seal lip portion 51 extending inward along the axis line x. Further, the seal portion 5 includes a dust lip portion 52 for preventing foreign matters such as dust from entering a contact portion between the seal lip portion 51 and a shaft (not shown) on the outside. As shown in FIG. 1, the dust lip 52 is an annular member centered on the axis x, and extends obliquely from the inner peripheral side end of the seal portion 5 outward in the inner peripheral direction.

  The seal lip portion 51 includes a lip tip portion 53 at an inner portion on the inner peripheral side thereof. As shown in FIG. 1, the lip tip 53 has a wedge shape that is convex in the inner circumferential direction in a cross section including the axis line x (hereinafter also referred to simply as a cross section), and has an annular protrusion centered on the axis line x. It is a striated body. Further, as shown in FIG. 1, the lip tip portion 53 has a first surface 54, a second surface 55, and a third surface 56 in order from the inside. A first surface 54, a second surface 55, and a third surface 56 are defined.

  As shown in FIG. 1, the first surface 54 is an annular surface centered on the axis line x, and is a conical surface (tapered surface) that tapers in the direction of the axis line x. The tapered surface of the first surface 54 is reduced in diameter from the inside toward the outside in the axis x direction.

  Similar to the first surface 54, the second surface 55 is an annular surface centered on the axis x as shown in FIG. 1, and is a conical surface (tapered surface) that tapers in the direction of the axis x. ). The tapered surface of the second surface 55 is reduced in diameter from the inside toward the outside in the direction of the axis x. As shown in FIG. 1, the inclination angle of the first surface 54 is larger than the inclination angle of the second surface 55. For this reason, the lip corner portion (connecting portion) 57, which is a portion where the first surface 54 and the second surface 55 are connected, is convex toward the axis x side (inner peripheral side).

  As shown in FIG. 1, the third surface 56 is an annular surface centering on the axis x, and is a conical surface (tapered surface) extending in a taper direction in the axis x direction. The tapered surface of the third surface 56 increases in diameter from the inner side toward the outer side in the axis x direction.

  As shown in FIG. 1, the contact portion 58, which is a connection portion between the second surface 55 and the third surface 56, is convex toward the inner peripheral side, and the lip tip portion 53 is the contact portion. At 58, the outer periphery of the shaft (not shown) is brought into liquid-tight contact with the sealing device 1 and the shaft is sealed.

  Further, the seal lip 51 includes an annular recess 59 on the outer peripheral surface facing the lip tip 53, and the recess 59 accommodates the annular spring 6 provided in the sealing device 1, and the lip tip The portion 53 is biased in the inner circumferential direction.

  As shown in FIG. 1, the main body 2 includes a hollow disk-shaped disk part 21 centering on the axis x, and the disk part 21 includes the attachment part 4 and the seal part 5. Each is connected at the outer end.

  The sealing device 1 is configured to prevent the seal lip 51 from turning over when a shaft (not shown) is inserted, and to prevent the spring 6 from falling off the recess 59. It has a configuration. Hereinafter, the turning-up preventing structure and the spring falling-off preventing structure will be described.

  The sealing device 1 includes a turn-up preventing protrusion 22 as a turn-up preventing structure of the seal lip portion 51. The turn-up prevention protrusion 22 is an annular ridge body centering on the axis line x that protrudes inward, and is provided at the inner end of the seal lip 51. As shown in FIG. 1, the outer end portion of the turn-up preventing projection 22 is connected to the first surface 54 of the lip tip portion 53 on the inner peripheral side and the second spring drop-off preventing projection 24 described later on the outer side. . As will be described later, when the seal lip 51 is deformed, the anti-flipping protrusion 22 abuts against the surface of a shaft (not shown) and exerts an anti-turning force to prevent the seal lip 51 from being turned up.

  Further, the sealing device 1 includes a first spring drop-off prevention protrusion 23 and a second spring drop-off prevention protrusion 24 as a structure for preventing the spring 6 from dropping from the recess. The first spring drop-off preventing projection 23 is an annular ridge that is centered on the axis line x that is convex in the outer circumferential direction, and is projected from the outer edge of the recess 59 as shown in FIG. Similarly, the second spring drop-off preventing projection 24 is an annular projecting body centering on the axis line x convex in the outer circumferential direction, and is projected on the inner edge of the recess 59 as shown in FIG. ing. In this way, the recess 59 is surrounded not only by the outer second spring dropout protrusion 24 but also by the inner first spring dropout protrusion 23.

  As shown in FIG. 1, the outer peripheral surface of the first spring drop-off prevention projection 23 increases in diameter from the outside toward the inside along the axis x. That is, as for the 1st spring drop-off prevention protrusion 23, the recessed part 59 side is higher toward the outer peripheral side. Further, the second spring drop-off prevention protrusion 24 is higher than the first spring drop-off prevention protrusion 23 toward the outer peripheral side. In this manner, the recess 59 is surrounded by the first spring drop-off prevention protrusion 23 and the second spring drop-off prevention protrusion 24 at both edges, thereby preventing the spring 6 from falling off the recess 59. Yes. In addition, the shape and size of the first spring drop-off prevention protrusion 23 and the second spring drop-off prevention protrusion 24 are not limited to those described above, and can be any one that can prevent the spring 6 from dropping from the recess 59. Other shapes and sizes may be used.

  The reinforcing ring 3 is an annular member centering on the axis line x having a substantially L-shaped cross section. As shown in FIG. 1, the reinforcing ring 3 is partially covered with the main body 2 and integrated with the main body 2. In the present embodiment, a part of the inner surface of the reinforcing ring 3 is exposed without being covered by the main body 2, but if the reinforcing ring 3 has a structure that can reinforce the main body 2, a part of the reinforcing ring 3 is the main body. Even if it is covered with 2, the whole body 2 may be covered.

  The reinforcing ring 3 is manufactured, for example, by pressing or forging, and as will be described later, most of the main body 2 is molded by vulcanization molding using a molding die. At the time of this vulcanization molding, the reinforcing ring 3 is disposed in the mold, and the reinforcing ring 3 and the main body 2 are integrally molded.

  Hereinafter, the use state of the sealing device 1 having the above-described configuration will be described. The sealing device 1 according to the present embodiment is arranged between a casing and a shaft, which are two members that rotate relative to each other. Specifically, the sealing device 1 is disposed in the gap between the shaft hole of the casing and the shaft inserted through the shaft hole in order to seal the gap.

  FIG. 2 is a partial cross-sectional view for illustrating a use state of the sealing device 1 according to the embodiment of the present invention.

  As shown in FIG. 2, the casing 71 includes a shaft hole 72 as a cylindrical opening, and a shaft 73 is inserted through the shaft hole 72. A sealing device 1 is attached to a gap 76 between an inner circumferential surface 74 that is an inner circumferential surface of the shaft hole 72 and an outer circumferential surface 75 that is a surface of the shaft 73 in order to seal the gap 76. .

  Specifically, the sealing device 1 is attached to the casing 71 with the attachment portion 4 fitted in the shaft hole 72 of the casing 71. More specifically, between the reinforcing ring 3 and the inner peripheral surface 74 of the shaft hole 72, the tightening allowance 42 of the mounting portion 4 is compressed, and the sealing device 1 is fitted into the casing 71 and firmly fixed. Has been. The outer peripheral surface 41 of the main body 2 is in liquid-tight contact with the inner peripheral surface 74 of the shaft hole 72. The shaft 73 is inserted into the seal portion 5, and the lip tip 53 (contact portion 58) of the seal lip portion 51 is in liquid-tight contact with the outer peripheral surface 75 of the shaft 73. The gap 76 is sealed by the fitting by the mounting portion 4 and the contact of the lip tip 53.

  Next, the operation of the turn-up prevention protrusion 22, the first spring drop-off prevention protrusion 23, and the second spring drop-off prevention protrusion 24 will be described.

  FIG. 3 is a view for showing a state in which a shaft is inserted into the sealing device 1 to obtain the use state of FIG.

  As shown in FIG. 3, when the shaft 73 is inserted into the sealing device 1, the lip tip 53 may be caught on the outer peripheral surface 75 of the shaft 73. In this case, as the shaft 73 is inserted, the seal lip portion 51 is bent and deformed in the direction of the shaft 73 with the outer base portion at the center. As the shaft 73 is further inserted, the seal lip portion 51 is further bent and deformed. However, as shown in FIG. A curling prevention force is generated by the protrusion 22, and further deformation of the seal lip portion 51 is stopped. This prevents the seal lip 51 from being turned up.

  As shown in FIGS. 3 and 4, when the curl prevention protrusion 22 contacts the outer peripheral surface 75 of the shaft 73, the lip corner portion 57 of the lip tip 53 contacts the outer peripheral surface 75 of the shaft 73. ) That is, the fulcrum of the anti-turning force generated by the contact of the anti-turning protrusion 22 is the lip corner portion 57 of the lip tip 53, and the magnitude of the anti-turning force is the lip corner portion 57 and the anti-turning protrusion 22 (anti-turning prevention). This is based on the distance (distance D) between the protrusion 22 and the contact portion with the shaft 73 (see FIG. 4). That is, as the distance D is larger, the turning prevention force generated by the contact of the turning prevention protrusions 22 is increased.

  In the sealing device 1, the lip tip portion 53 includes two surfaces, a first surface 54 and a second surface 55, on the inner surface, and the first surface 54 of the lip tip portion 53 is a tapered surface as described above. Therefore, the distance D can be increased, and the turning-up preventing power can be increased. For this reason, the seal lip 51 can be prevented from being turned over, and the spring 6 can be prevented from falling off the recess 59.

  Further, the closer to the outer peripheral surface 75 of the shaft 73, the more the anti-flipping protrusion 22 is in the state where the seal lip portion 51 is not deformed, the more the deformation of the seal lip portion 51 is brought into contact with the shaft 73. This is advantageous in preventing turning over. In the sealing device 1, since the first surface 54 of the lip tip 53 is a tapered surface as described above, it is prevented from turning over when the seal lip 51 is not deformed while increasing the distance D. The protrusion 22 can be brought close to the outer peripheral surface 75 of the shaft 73. For this reason, in the sealing device 1, the turning prevention force can be generated with a slight deformation of the seal lip 51.

  Further, as the angle of the tapered surface of the first surface 54 is smaller, the interval D can be increased and the turn-up preventing force can be increased. That is, as the angle (angle α) between the first surface 54 and the second surface 55 is larger (see FIG. 4), the interval D can be increased and the turn-up preventing force can be increased.

  In addition, since the first spring drop-off prevention protrusion 22 and the second spring drop-off prevention protrusion 23 are provided at both edges of the recess 59, the spring 6 remains in the recess even when the seal lip 51 is deformed. It is possible to prevent dropping from 59.

  Next, a manufacturing method of the sealing device according to the embodiment of the present invention will be described.

  As described above, in the sealing device 1 according to the embodiment of the present invention, in order to increase the turning-preventing force, the lip tip portion 53 includes the first surface 54, the second surface 55, and the third surface. Surface 56. Conventionally, a knife cut has been performed to form the lip tip 53, but there is a possibility that the turning prevention protrusion 22 may be cut or damaged by the knife cut. The manufacturing method of the sealing device according to the present invention prevents the turning prevention protrusion 22 from being damaged by cutting the turning prevention protrusion 22 with a knife cut.

  Hereinafter, in the description of the manufacturing method of the sealing device according to the embodiment of the present invention, the description of the same steps as the conventionally known method is omitted.

  FIG. 5 is a diagram for schematically showing a lip tip portion forming step in the method for manufacturing the sealing device 1 according to the embodiment of the present invention.

  As shown in FIG. 5, in the vulcanization molding step, the main body 2 is formed integrally with the reinforcing ring 3 by vulcanization molding using a molding die. However, the lip tip 53 is not yet completely formed by this vulcanization molding process. That is, between the first surface 54 and the third surface 56 of the lip distal end portion 53, as shown in FIG. 5, a surplus portion 61 made of excess material is formed.

  When this vulcanization molding step is finished, a lip tip portion forming step is then performed. In the step of forming the lip tip, as shown in FIG. 5, the second surface 55 is formed by scalpel cutting (dashed line in FIG. 5). By this knife cutting, the length (width) of the first surface 54 and the third surface 56 is also defined, and the lip tip 53 is formed. As described above, the first surface 54 and the third surface 56 of the lip tip 53 are molded, and the second surface 55 is molded by a knife cut.

  Thus, in the manufacturing method of the sealing device according to the embodiment of the present invention, after the first surface 54 and the third surface 56 of the lip tip 53 are molded, the second surface 55 is formed by a knife cut. Since the molding is performed, the turning prevention protrusion 22 does not interfere with the knife cut, and the turning prevention protrusion 22 is not damaged by the knife cutting. Moreover, manufacture of the lip | tip front-end | tip part 53 can be made easy.

  Further, in the sealing device 1, since the first surface 54 of the lip tip 53 is a tapered surface as described above, the turning prevention protrusion 22 is inserted into the shaft 73 when the seal lip 51 is not deformed. Even when the shape is close to the outer peripheral surface 75, the turning prevention protrusion 22 does not interfere with the knife cutting, and the turning prevention protrusion 22 is not damaged by the knife cutting.

  As described above, according to the sealing device 1 according to the embodiment of the present invention, the turning prevention force based on the turning prevention protrusion 22 can be improved, and the turning of the seal lip portion 51 can be prevented. Thereby, the deformation of the seal lip portion 51 can be suppressed, and the spring 6 can be prevented from falling off the recess 59.

  In addition, since the first spring drop-off prevention protrusion 23 and the second spring drop-off prevention protrusion 24 are provided on both edges of the recess 59, the spring 6 can be prevented from falling off the recess 59. .

  Further, as described above, according to the manufacturing method of the sealing device according to the embodiment of the present invention, the turning prevention protrusion 22 does not get in the way when the second surface 55 is formed by the knife cut. The molding of the second surface 55 can be facilitated. This also prevents the turn-up preventing projection 22 from being damaged during the manufacturing of the sealing device 1.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments of the present invention, and includes all aspects included in the concept and claims of the present invention. In addition, the configurations may be appropriately combined as appropriate so as to achieve at least part of the problems and effects described above. For example, the shape, material, arrangement, size, and the like of each component in the above embodiment can be appropriately changed according to the specific usage mode of the present invention. Specifically, the shapes of the attachment portion 4, the seal portion 5, and the reinforcing ring 3 are not limited to the shapes described above.

  In addition, the sealing device 1 according to the present embodiment is applied to the gap between the casing and the drive shaft inserted through the opening of the casing. The present invention is not limited, and the present invention is applicable to all configurations that can utilize the effects of the present invention.

DESCRIPTION OF SYMBOLS 1,100 Sealing device 2,106 Main body 3,105 Reinforcement ring 4,107 Mounting portion 5,108 Seal portion 6,112 Spring 21 Disk portion 22, 113 Turn-up prevention projection 23 First spring drop-off prevention projection 24 Second Spring drop-off prevention protrusions 41 and 107a Outer peripheral surface 42 Fastening margin portions 51 and 109 Seal lip portion 52 Dustrip portion 53 and 110 Lip tip portion 54 First surface 55 Second surface 56 Third surface 57 Lip corner portion 58 Contact portion 59, 111 Recess 61, 114 Saddle portion 71, 101 Casing 72, 103 Shaft hole 73, 102 Shaft 74 Inner peripheral surface 75 Outer peripheral surface 76, 104 Gap 110a Inner side surface 110b Outer side surface 115 Inner end surface 116 Connection portion D Interval x axis α angle

Claims (6)

A sealing device that seals a gap between two members that are rotatable relative to each other with respect to an axis, comprising: a main body made of an elastic body; and an annular spring centered on the axis, the main body comprising the two members An annular mounting portion centered on the axis, which is fitted to a mounted portion on one side, and a seal portion that is slidably in close contact with the other of the two members, the seal portion including the axis An annular seal lip portion is provided at the center, and the seal lip portion is centered on a lip tip portion which is an annular ridge projecting toward the axis, and the axis provided to face the lip tip portion. An annular recess, and the spring is accommodated in the recess, and the end of the seal lip portion on the object to be sealed side is a ring-shaped protrusion projecting toward the object to be sealed. In the sealing device provided with a certain turn prevention protrusion,
The lip tip includes a first surface, a second surface, and a third surface in order from the sealing object side, and the first surface extends from the sealing object side to the sealing object side. Is a tapered surface that decreases in diameter toward the opposite side, and the second surface is a tapered surface that decreases in diameter from the sealing object side toward the opposite side to the sealing object side, and the third surface face Ri tapered surface der whose diameter increases toward the opposite side of the said sealing object side from the sealed object side,
The connecting portion between the first surface and the second surface is convex toward the axis side,
In the lip tip, the first surface is connected to the anti-flipping projection,
A connecting portion between the second surface and the third surface is slidably in contact with the other of the two members;
When the turn-up preventing projection comes into contact with the other of the two members, the connecting portion between the first surface and the second surface of the lip tip can come into contact with the other of the two members. A sealing device characterized by that. The seal portion includes a first spring drop-off preventing protrusion that is an annular protrusion protruding from an edge of the recess opposite to the object to be sealed, and an edge of the recess on the object to be sealed side Department sealing device according to claim 1, further comprising a second spring disengagement prevention projection is projection of convexly been annular. The sealing device according to claim 2, wherein the first spring drop-off preventing protrusion has a diameter increased toward the sealing object. Comprising a reinforcing ring of annular shape centered on said axis, reinforcing ring, at least in part according to claim 1 to 3, characterized in that covered by the main body according to any one of the sealing device. A method for manufacturing a sealing device according to any one of claims 1 to 4 ,
A method of manufacturing a sealing device, wherein after forming the first surface and the third surface, the lip tip is formed by forming the second surface with a knife cut. The first surface and the third surface are molded with an excess surplus portion between the first surface and the third surface, and the second surface is the surplus portion. 6. The method for manufacturing a sealing device according to claim 5 , wherein the sealing device is molded by cutting a knife.

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