JP2010203551A - Plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To downsize a plug by forming a seal surface in the inner part of a port. <P>SOLUTION: The plug 100 is fitted in the port 50 formed on hydraulic equipment, and can block the port 50. The plug 100 includes a male screw portion 11 fastened with a female screw portion 60 formed in the port 50, and the seal surface 25 formed in the inner part of the port 50 than the male screw portion 11 and tightly contacting with a seal step portion 65 formed in the port 50 to seal hydraulic oil. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plug capable of closing a port formed in a fluid pressure device or the like.

  2. Description of the Related Art Conventionally, in order to close a port formed by opening to the outside in a fluid pressure device, a configuration in which a plug is screwed into the port and closed is widely used. In this configuration, the working fluid is sealed by bringing the sealing surface formed on the port surface into close contact with the sealing surface formed on the plug.

  Patent Document 1 discloses a plug structure that closes a port by compressing a seal member between a flange formed on the plug and a seal groove.

JP 2007-78094 A

  However, in the plug structure as disclosed in Patent Document 1, it is necessary to form a surface corresponding to the size of the flange portion of the plug on the opening surface of the port, which hinders miniaturization of the fluid pressure device.

  Accordingly, an object of the present invention is to provide a small plug.

  The present invention is a plug that is fitted into a port formed in a fluid pressure device and can close the port, and a fastening portion fastened to a fastened portion formed in the port, And a sealing surface formed in the back of the port and sealing the working fluid in close contact with a sealing step formed in the port.

  In the present invention, since the seal surface is formed at the back of the port, it is not necessary to form a flange on the outer periphery of the male screw portion in order to close the port. Therefore, the plug can be reduced in size.

It is the front view of the plug which concerns on embodiment of this invention, and is the figure which showed a part in cross section. It is a top view in FIG. It is a bottom view in FIG.

  Hereinafter, a plug 100 according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, hydraulic pressure is used as the fluid pressure.

  The plug 100 is inserted into a port 50 formed in a hydraulic device (fluid pressure device) to close the port 50. The plug 100 can be used not only as a hydraulic device but also as a pneumatic device, for example, as means for closing the port 50.

  First, the port 50 into which the plug 100 is inserted will be described with reference to FIG.

  The port 50 is a substantially cylindrical through-hole provided to communicate with the outside from a pipe 70 that is a hydraulic oil passage in the hydraulic device. The port 50 is formed with a larger diameter than the tube 70.

  The port 50 includes a female screw portion 60 as a fastened portion formed from the port surface 52 toward the back, and a non-screwing portion 62 formed deeper than the female screw portion 60. A further depth of the non-threaded portion 62 communicates with the tube 70. A seal step 65 is provided between the bottom surface of the port 50, that is, between the non-threaded portion 62 and the pipe 70.

  The port 50 is formed by first cutting from the port surface 52 to the seal step portion 65 with the diameter of the non-threaded portion 62, and then cutting the female screw of the female screw portion 60.

  The female thread portion 60 has a female thread formed on the inner periphery. The female thread is a normal metric thread, but may be another parallel female thread for pipes. The female thread portion 60 is formed from the port surface 52 to the back of the port 50 by a predetermined axial depth. Here, the predetermined axial depth is an axial depth at which the male screw portion 11 of the plug 100 described later can be screwed into the female screw portion 60 and the port 50 can be sealed.

  A non-screwing portion 62 is provided at the back of the female screw portion 60. A female screw is not formed in the non-threaded portion 62. The inner diameter of the non-threaded portion 62 is formed substantially the same as the inner diameter of the thread of the female screw portion 60. The sum of the axial depths of the female thread portion 60 and the non-threaded portion 62 is the depth of the port 50.

  The seal step portion 65 is a surface formed in a ring shape with a predetermined width on a surface substantially perpendicular to the axis of the port 50. The seal step portion 65 is precisely finished so as to be able to seal the hydraulic oil by being in close contact with a seal surface 25 of the plug 100 described later.

  Next, the plug 100 will be described with reference to FIGS.

  The plug 100 includes a substantially cylindrical large-diameter head 10 and a substantially cylindrical small-diameter seal portion 20 formed from the bottom surface of the head 10 toward the back of the port 50. The head portion 10 and the seal portion 20 are formed coaxially.

  On the outer periphery of the head 10, a male screw portion 11 is provided as a fastening portion that can be screwed with the female screw portion 60 formed in the port 50. A normal metric screw corresponding to the female screw portion 60 is formed in the male screw portion 11. When the female screw portion 60 is a pipe parallel female screw, the male screw portion 11 is formed with a pipe parallel male screw corresponding to the female screw portion 60. The male screw portion 11 is formed over the entire axial height of the head portion 10.

  The axial height of the male screw portion 11 is not limited to this embodiment. For example, the male screw portion 11 may be formed over the entire axial height of the plug 100. In this case, the female thread portion 60 of the port 50 is formed over the entire depth of the port 50. Thus, the internal thread portion 60 of the port 50 may be formed in correspondence with the axial position and the axial height of the external thread portion 11. However, the present invention is not limited to this, and the internal thread portion 60 may be formed so that a seal surface 25 described later can be in close contact with the seal step portion 65 in a state where the external thread portion 11 and the internal thread portion 60 are screwed together. Therefore, it is possible to form the female screw portion 60 deeper than the depth corresponding to the axial height of the male screw portion 11. For example, the male screw portion 11 may be formed to a height as shown in FIG. 1, the female screw portion 60 of the port 50 may be extended to the seal step portion 65, and the female screw portion 60 may be formed on the entire inner periphery of the port 50. In that case, the non-threaded portion 62 is not formed in the port 50.

  A hexagonal hole 15 is formed at the center of the top surface of the head 10. The hexagon hole 15 is a hexagonal deep hole that can be fastened from the outside of the port 50 with a hexagon wrench. In addition to the hexagonal hole 15, for example, a deep hole having a special shape that can be fastened using a dedicated tool may be formed.

  The seal portion 20 protrudes from the bottom surface of the head portion 10 and has a smaller diameter than the screw seat of the female screw portion 60 of the head portion 10. The outer diameter of the seal portion 20 is formed smaller than the inner diameter of the non-threaded portion 62 of the port 50. Therefore, when the plug 100 is inserted, the plug 100 is opposed to the non-threaded portion 62 with a gap. On the bottom surface of the seal portion 20, a seal surface 25 that is in close contact with the seal step portion 65 formed in the port 50 is formed. A recess 27 is formed on the inner periphery of the seal portion 25.

  The seal surface 25 is a surface formed in a ring shape with a predetermined width on the bottom surface of the seal portion 20. The seal surface 25 is formed substantially perpendicular to the axis of the plug 100. Here, it is also possible to form the sealing surface 25 in a tapered shape with respect to the axis of the plug 100 instead of being substantially perpendicular to the axis of the plug 100. In that case, the seal step portion 65 of the port 50 that is in close contact with the seal surface 25 also needs to be tapered at the same angle. This is for bringing the sealing surface 25 and the sealing step portion 65 into surface contact with each other.

  The seal surface 25 is precisely finished so as to be in close contact with the seal step 65 of the port 50 and seal the hydraulic oil or the like. Here, the predetermined width is a width that allows the hydraulic oil to be sealed in close contact with the seal step portion 65. Similarly, the predetermined width of the seal step portion 65 described above is a width that can contact the seal surface 25 and seal the hydraulic oil.

  Since the seal step portion 65 is formed on the bottom surface of the port 50, the seal step portion 65 can be formed at the same time when the non-threaded portion 62 of the port 50 is processed. For this reason, the perpendicularity and surface roughness of the surface with respect to the central axis of the port 50 can be easily obtained as compared with the case where the surface is formed on the surface of the hydraulic device. Therefore, processing is easier than the conventional configuration.

  In the plug 100, the seal surface 25 is directly brought into intimate contact with a precisely finished seal step 65, but in addition, an O-ring is provided between the seal surface 25 of the plug 100 and the seal step 65 of the port 50. The hydraulic oil may be sealed by compressing a sealing member such as.

  The concave portion 27 is formed at the center of the bottom surface of the seal portion 20 of the plug 100, and is formed so as to be recessed in the axial direction of the port 50 from the seal surface 25. The recess 27 is formed in a portion other than the seal surface 25 formed in an annular shape on the bottom surface of the seal portion 20. Thereby, the contact between the seal surface 25 and the seal step portion 65 is ensured, and the seal surface 25 can be reliably brought into close contact with the seal step portion 65. This is because the concave portion 27 is formed so that the portion protruding beyond the seal surface 25 to the back of the port 50 does not exist in the seal portion 20.

  In addition, the sealing surface 25 needs to be finished with a high degree of squareness and surface roughness with respect to the central axis of the plug 100, but the processing area of the sealing surface 25 is reduced by providing the recess 27. Therefore, the processing cost can be reduced.

  Further, since the concave portion 27 exists at the center of the bottom surface of the seal portion 20, for example, when the seal surface 25 is formed by milling, the milling blade surface and the seal when the milling cutter moves from the side surface of the seal surface 25. The rate of change of the contact area with the surface 25 is reduced. Therefore, the stable and accurate sealing surface 25 can be realized.

  By the way, conventionally, the working oil is sealed by bringing the flange formed on the plug into close contact with the port surface 52. In this configuration, the plug itself needs to be provided with a flange, and the surface of the port surface 52 needs to be formed on the surface of the port 52 so that the flange of the plug is brought into close contact with the hydraulic device.

  On the other hand, in the plug 100, since it is not necessary to provide a flange portion, the plug 100 can be downsized, and at the same time, the hydraulic equipment can be downsized. In addition, the degree of freedom of layout in the hydraulic equipment is increased.

  Further, in the conventional configuration in which the port surface 52 and the flange portion of the plug are sealed tightly, when the plug is strongly fastened, the flange portion that is in close contact with the port surface 52 is deformed by the force from the port surface 52 and the degree of adhesion is increased. There was a risk that it would become low.

  On the other hand, in the plug 100, it is not necessary to provide a flange portion, and the seal surface 25 formed on the bottom surface of the plug 100 and the seal step portion 65 formed on the port 50 are provided separately from the screw fastening portion. . In addition, there is no risk of deformation because the portions having high structural rigidity are in close contact with each other. Therefore, the sealing property can be kept good.

  Further, in the configuration in which the port surface 52 and the flange portion of the plug are sealed as in the conventional case, the screwed portion is located behind the port 50 rather than the seal surface, so the screwed portion is exposed to the hydraulic oil. It was. For this reason, there is a possibility that the screwing portion is likely to be loosened due to the lubricating effect of the hydraulic oil.

  On the other hand, in the plug 100, the sealing surface 25 is formed at the back of the port 50 rather than the male screw portion 11. By forming in this way, the hydraulic oil in the pipe 70 does not go out of the port 50 beyond the seal surface 25, and the female screw portion 60 and the male screw portion 11 that are screwed together are not exposed to the hydraulic oil. Therefore, it is possible to prevent the female screw portion 60 and the male screw portion 11 that are screwed together by the lubricating effect of the hydraulic oil from being loosened.

  Similarly, if the threaded portion is located behind the port 50 rather than the sealing surface, the facet generated from the threaded portion when the plug is fastened may enter the inside of the tube 70.

  On the other hand, in the plug 100, since the seal surface 25 is formed in the back of the port 50 rather than the male screw portion 11, foreign matters such as facets generated when the plug 100 is fastened enter the tube 70 in the back of the seal surface 25. It is possible to prevent entry.

  Further, in the conventional configuration in which the port surface 52 and the flange portion of the plug are sealed in close contact, the seal portion that contacts the flange portion is exposed to the outside of the hydraulic device. In this configuration, it is necessary to be careful not to deform the seal portion due to dents or scratches during transportation.

  On the other hand, in the plug 100, the seal step 65 is formed in the back of the port 50 and is not exposed on the surface of the hydraulic device. Therefore, there is little risk of dents and scratches during transportation and the like, and deformation of the seal portion can be prevented.

  According to the above embodiment, the following effects are obtained.

  In the plug 100, the sealing surface 25 is formed at the back of the port 50 rather than the male screw portion 11, so that it is not necessary to form a flange on the outer periphery of the male screw portion 11 in order to close the port 50. Therefore, the plug can be reduced in size.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The plug according to the present invention can be used to close a port provided in a hydraulic device or a pneumatic device.

DESCRIPTION OF SYMBOLS 100 Plug 10 Head 11 Male thread part 20 Seal part 25 Seal surface 50 Port 52 Port surface 60 Female thread part 62 Non-screw part 65 Seal step part

Claims (4)

A plug that is fitted into a port formed in the fluid pressure device and can close the port,
A fastening portion fastened to a fastened portion formed in the port;
A plug comprising: a seal surface formed in the back of the port rather than the fastening portion and sealing a working fluid in close contact with a seal step formed in the port. A head having the fastening portion;
A seal portion having the seal surface,
The plug according to claim 1, wherein the head is formed to have a larger diameter than the seal portion.   The plug according to claim 2, wherein the seal surface is formed on a bottom surface of the seal portion.   4. The plug according to claim 2, wherein a concave portion is formed on a bottom surface of the seal portion so as to ensure contact between the seal surface and the seal stepped portion.

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