JP2019128279A - Seal device for leak test - Google Patents

Abstract

To provide a seal device for a leak test having good sealing performance.SOLUTION: A seal device for a leak test 1 attached to a cylindrical part 20 having, on the outer peripheral surface, a taper surface 20b reduced in diameter toward an opening end face 20a comprises a seal member 9 pressed against the taper surface 20b to be annularly brought into contact therewith in the peripheral direction. Since the seal member 9 is brought into contact with the taper surface 20b of the cylindrical part 20, adhesion of the seal member 9 to the cylindrical part 20 (taper surface 20b) can be excellently secured.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a seal device for leak test.

  In a work such as an engine that requires air tightness, a fluid such as air is supplied to the internal space of the work, and a leak test is performed to check whether there is a leak by measuring the fluid pressure. (See Patent Document 1 below).

  In order to conduct such a leak test, it is necessary to seal all the openings leading to the internal space to be tested. For example, in the leak test of the cooling water flow path in the engine, the opening end face of the cylindrical portion for sealing all the openings of the cylindrical portion (port) for the cooling water inlet and the cooling water outlet provided in the engine A seal member is brought into contact with the (front end surface) to prevent air leakage from the open end surface.

JP-A-9-159566

  However, in the conventional seal structure, the cylindrical portion cannot be completely sealed, and air leakage may occur. And since such an air leak becomes a factor of the misjudgment in a leak test, the improvement was calculated | required.

  Then, when the cause of such a problem was investigated, it turned out that the surface roughness of the opening end face of a cylindrical part originates in the sealability between a cylindrical part and a seal member. . That is, since the opening end surface of the cylindrical portion is formed with a relatively rough surface, it is difficult to obtain sufficient adhesion with the seal member due to minute irregularities generated on the opening end surface, and air leaks from a slight gap. It turned out that there was a risk. In addition, the seal member may be damaged or deteriorated due to burrs or burrs generated on the open end face when the cylindrical portion is processed, which is also considered to be a cause of the decrease in the sealing property.

  An object of this invention is to provide the seal | sticker apparatus for leak tests in which favorable sealability is obtained in view of such a situation.

  In order to solve the above-mentioned subject, the present invention is a seal device for leak tests attached to a cylindrical part which has a taper surface which diameter reduces toward an opening end face in a peripheral face, and is pressed against a taper surface Provided is a seal device for leak testing, comprising a seal member that makes an annular contact in the circumferential direction.

  Thus, in the leak test seal device according to the present invention, the seal member is brought into contact with the tapered surface of the cylindrical portion, thereby ensuring good adhesion of the seal member to the cylindrical portion (tapered surface). can do.

  According to the present invention, it is possible to satisfactorily ensure the adhesion of the sealing member to the tubular portion, and thus the sealing performance is improved.

It is a sectional view of a seal device concerning an embodiment of the present invention. It is sectional drawing of the cylindrical part with which the sealing device which concerns on this embodiment is mounted | worn. It is sectional drawing which shows the state which slid the outer cylinder. It is sectional drawing which shows the state in the middle of mounting | wearing with a sealing apparatus with respect to a cylindrical part. It is sectional drawing which shows the state with which the sealing device was mounted | worn with respect to the cylindrical part. It is sectional drawing which expands and shows the state which the sealing member contacted with respect to the cylindrical part. It is sectional drawing which expands and shows a sealing member. It is sectional drawing of the example in which the through-hole is not provided in the valve body. It is sectional drawing for demonstrating the effect | action of the sealing apparatus which concerns on this embodiment. It is sectional drawing which shows the modification of a sealing member. It is sectional drawing which shows another modification of a sealing member.

  Hereinafter, an embodiment of a leak test seal device according to the present invention will be described.

  FIG. 1 is a cross-sectional view of a leak test sealing apparatus according to the present embodiment.

  As shown in FIG. 1, the seal device 1 for a leak test according to the present embodiment includes a cylindrical outer cylinder 2, a cylindrical inner cylinder 3 inserted in the outer cylinder 2, and an inner cylinder 3. A first spring as a biasing member for biasing the outer cylinder 2 toward the tip end of the inner cylinder 3 (in the direction of the arrow A in the figure) 6, a second spring 7 as a biasing member that biases the valve body 4 toward the tip end side (in the direction of arrow C in the figure) of the inner cylinder 3, and a plurality of lock balls 8 as lock members. And

  The outer cylinder 2 and the inner cylinder 3 are assembled so as to be relatively movable in the axial direction, and usually in a state where the outer cylinder 2 is moved to the tip end side of the inner cylinder 3 by the biasing force of the first spring 6 It is held. The first spring 6 is mounted in a compressed state between the step portions 2a and 3a provided on the inner peripheral surface of the outer cylinder 2 and the outer peripheral surface of the inner cylinder 3, respectively. A plurality of recesses 2 b into which the lock ball 8 can enter is provided on the inner peripheral surface of the outer cylinder 2. The lock ball 8 is provided so as to be movable outward and inward in the radial direction with respect to the inner cylinder 3. As indicated by a two-dot chain line in FIG. 1, the outer cylinder 2 is moved toward the rear end side (in the direction of arrow B in the figure) of the inner cylinder 3 against the urging force of the first spring 6, and the outer cylinder 2 When the concave portion 2b is disposed at a position corresponding to the lock ball 8, the lock ball 8 enters the concave portion 2b and is movable in the radial direction.

  The valve body 4 is accommodated in the inner cylinder 3 so as to be movable in the axial direction. Concave seat surfaces 4a and 5a for receiving the end portion of the second spring 7 are formed on the rear end surface of the valve body 4 and the front end surface of the valve seat 5, respectively. A second seat is formed between the seat surfaces 4a and 5a. The spring 7 is disposed in a compressed state. Although the valve body 4 is always urged toward the tip end portion side of the inner cylinder 3 by the second spring 7, the step portion 4 b provided on each of the outer peripheral surface of the valve body 4 and the inner peripheral surface of the inner cylinder 3 The valve body 4 is prevented from coming off from the inside of the inner cylinder 3 by the parts 3b engaging with each other and functioning as a stopper. The valve body 4 is provided with a through hole 4c formed so as to penetrate from the front end surface to the rear end surface.

  As shown in FIG. 1, a cylindrical seal member 9 made of an elastic material such as rubber is provided at the tip of the valve body 4. The seal member 9 has an inner peripheral surface formed in a stepped shape, and has a first seal portion 10 having a large inner diameter, and is positioned closer to the rear end portion of the valve body 4 than the first seal portion 10, and the first seal portion And a second seal portion 11 having an inner diameter smaller than 10. Further, an O-ring (rubber ring) 12 as another seal member is attached to the outer peripheral surface of the valve body 4, and the space between the valve body 4 and the inner cylinder 3 is sealed by the O-ring 12.

  The valve seat 5 is fitted and fixed to the rear end portion of the inner cylinder 3. An O-ring (rubber ring) 13 as a seal member is mounted on the outer peripheral surface of the valve seat 5, and the O-ring 13 seals the space between the valve seat 5 and the inner cylinder 3.

  Next, a method of using the sealing device according to the present embodiment will be described by taking a case where the sealing device is used for a leak test of a cooling water flow path of an automobile engine as an example. However, the leak test seal device according to the present invention is not limited to the leak test of the engine cooling water flow path, but the leak test of the oil flow path of the engine, the air flow path for supply and exhaust, and other than the engine It is applicable also to the leak test done to a work.

  FIG. 2 is a cross-sectional view of a cylindrical portion to which the sealing device according to the present embodiment is attached.

  The tubular portion 20 is a portion to which a pipe member such as a hose for circulating the cooling water between the engine and the radiator is attached, and as shown in FIG. It is provided to project outward from the engine 30 so as to A plurality of cylindrical portions 20 are provided for cooling water inlets and cooling water outlets, and an opening end surface 20a (tip surface) is provided on the outer peripheral surface of each cylindrical portion 20 so that a pipe member can be easily attached. The taper surface 20b is formed to reduce the diameter toward the surface.

  In order to conduct the leak test, it is necessary to mount the sealing device according to the present embodiment to the cylindrical portion to seal the opening of the cylindrical portion. Note that the sealing device is attached to all other cylindrical portions except for one of the plurality of cylindrical portions. An air supply device (not shown), which is a test fluid supply device, is connected to the remaining one cylindrical portion.

  In order to mount the seal device on the cylindrical portion, first, as shown in FIG. 3, the rear end side of the inner cylinder 3 against the biasing force of the first spring 6 against the outer cylinder 2 of the seal device 1 Slide to Next, as shown in FIG. 4, the sealing device 1 is inserted into the inner cylinder 3 with respect to the cylindrical portion 20 so that the cylindrical portion 20 is inserted into the inner cylinder 3 while holding the outer cylinder 2 in a sliding movement state. Plug in. At this time, the lock ball 8 is capable of entering into the recess 2 b of the outer cylinder 2, so that the lock ball 8 is pushed outward along the tapered surface 20 b of the cylindrical portion 20 in the radial direction. It is possible to get over the tapered surface 20b.

  Then, as shown in FIG. 5, the holding of the outer cylinder 2 is released in a state where the opening end surface 20 a and the tapered surface 20 b of the cylindrical portion 20 are pressed against the seal member 9 of the valve body 4. Thereby, the outer cylinder 2 is pushed to the tip end side of the inner cylinder 3 by the urging force of the first spring 6, and the lock ball 8 is the inner peripheral surface of the outer cylinder 2 (portion without the recess 2 b) and the cylindrical portion 20 And the outer peripheral surface of the As a result, the lock ball 8 is pressed against the outer peripheral surface of the cylindrical portion 20, and the sealing device 1 is fixed to the cylindrical portion 20. Thereby, the attachment of the seal device 1 to the cylindrical portion 20 is completed.

  In addition, the sealing device is attached to the other cylindrical portion in the same procedure. Then, air is supplied from the air supply device into the fluid path of the engine, and a leak test is performed to check for air leakage. In order to remove the seal device from the cylindrical portion after the leak test is completed, the removal operation may be performed in the reverse procedure of the above installation procedure. Specifically, the outer cylinder 2 is slidingly moved toward the rear end of the inner cylinder 3 against the biasing force of the first spring 6, and the fixation by the lock ball 8 is released. That is, by sliding the outer cylinder 2 to the rear end side of the inner cylinder 3, the lock ball 8 can enter the recess 2 b of the outer cylinder 2. The fixed state pressed against the outer peripheral surface is released. And the sealing apparatus 1 is pulled out from the cylindrical part 20, and is removed, hold | maintaining the outer cylinder 2 in the slid state.

  In a state where the seal device 1 is attached to the cylindrical portion 20, as shown in FIG. 6, the seal member 9 of the valve body 4 is pressed against the opening end face 20a and the tapered surface 20b of the cylindrical portion 20. Thereby, it seals in two places, the opening end surface 20a and the taper surface 20b. Specifically, the first seal portion 10 of the seal member 9 is pressed against the tapered surface 20 b of the cylindrical portion 20, and the second seal portion 11 of the seal member 9 is pushed against the open end face 20 a of the cylindrical portion 20. It is applied.

  As described above, in the seal device 1 according to the present embodiment, the first seal portion 10 contacts the tapered surface 20 b of the cylindrical portion 20 in the mounting state with respect to the cylindrical portion 20, and the second seal portion 11 By contacting the open end face 20 a of the cylindrical portion 20, the tapered face 20 b and the open end face 20 a can be sealed at two points. In particular, since the outer peripheral surface of the cylindrical portion 20 including the tapered surface 20b is a portion to which a pipe member such as a hose is attached, generally, the processing quality is better and the surface roughness is smaller than the open end surface 20a. Adhesiveness is excellently obtained between the tapered surface 20b having such a small surface roughness and the first seal portion 10. In the conventional configuration, since the sealing member is brought into contact only with the opening end surface having a relatively large surface roughness of the cylindrical portion, there is a possibility that air leaks from the sealing portion. However, in the sealing device 1 according to the present embodiment, Since the seal member 9 (first seal portion 10) is brought into contact with the tapered surface 20b having a small surface roughness, good adhesion can be obtained, and air leakage from the seal portion can be reliably prevented. Further, since the taper surface 20b is free from burrs and burrs, the deterioration of the seal member 9 (first seal portion 10) can be suppressed, and good sealing performance can be maintained over a long period of time.

  Further, the first seal portion 10 according to the present embodiment is formed in a rectangular shape in cross section having substantially square corner portions E (see FIG. 7), and the first seal portion 10 is pressed against the tapered surface 20b. At that time, the corner E is compressed (see FIG. 6). At this time, since the corner portion E of the first seal portion 10 is elastically deformed moderately, the first seal portion 10 contacts the taper surface 20b in an annular shape in the circumferential direction (entire circumference), and a good seal is obtained. It is possible to demonstrate the nature.

  Further, the outer peripheral surface of the first seal portion 10 is supported by the inner peripheral surface of the valve body 4 so as not to open too radially outward when pressed against the tapered surface 20b (see FIG. 6) . The valve body 4 is made of a rigid member such as metal, and by supporting the first seal portion 10 from the outer peripheral side, the adhesion of the first seal portion 10 to the tapered surface 20 b can be obtained. I am assisting.

  Further, in the sealing device 1 according to the present embodiment, the second seal portion 11 is in contact with the opening end surface 20a of the cylindrical portion 20 and sealed, so that the first seal portion 10 is not elastically deformed excessively. It also plays a role of regulating the insertion position of the cylindrical portion 20. Thereby, the excessive elastic deformation of the 1st seal part 10 by pushing in of the cylindrical part 20 can be suppressed, the moderate elastic deformation of the 1st seal part 10 is enabled, and favorable sealing performance comes to be obtained.

  Further, in the seal device 1 according to the present embodiment, the valve body 4 is provided with the through holes 4c (see FIG. 1), whereby the sealing performance is improved. On the contrary, in the case where there is no through hole 4c in this respect, as shown in FIG. 8, the valve body 4 is pushed by the air pressure P by receiving the air pressure P from the tip side thereof. As a result, the adhesion between the open end face 20a of the cylindrical portion 20 and the seal member 9 is reduced, and air may leak. On the other hand, when the through hole 4c is provided in the valve body 4 as in the seal device 1 according to the present embodiment, as shown in FIG. 9, a part of the air passes through the through hole 4c and the valve Since it moves to the rear end face side of the body 4, the valve body 4 comes to receive the air pressure P from the rear end face side, and the adhesion of the seal member 9 to the open end face 20a and the tapered face 20b of the cylindrical portion 20 is improved. At the same time, the attitude of the valve 4 is stabilized. Further, as described above, by allowing the valve body 4 to receive the air pressure P from the rear end face side, a measure is taken to increase the biasing force of the second spring 7 in order to stabilize the posture of the valve body 4. Since there is no need to take such a measure, it is possible to avoid a decrease in maintainability associated with strengthening the spring force. When the through hole 4 c is provided, air moving to the rear end face side of the valve body 4 intrudes also into the gap between the valve body 4 and the inner cylinder 3 and the gap between the valve seat 5 and the inner cylinder 3. Since these are sealed by O-rings 12 and 13, air leakage is prevented.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

  For example, as in the example shown in FIG. 10, the first seal portion 10 and the second seal portion 11 are constituted by separate seal members, and further, the first seal portion 10 is a seal having a rectangular cross section having corner portions. Instead of a member, it may be a sealing member without a corner formed in a circular cross section or the like. In this case, the first seal portion 10 and the second seal portion 11 can be made of materials different from each other, and materials suitable for the respective functions can be selected. For example, in consideration of the function of each sealing portion, rubber having a hardness of 50 ° can be selected as the material of the first sealing portion 10, and rubber having a hardness of 30 ° to 40 ° can be selected as the material of the second sealing portion 11.

  Moreover, in the above-mentioned embodiment, in order to suppress the excessive elastic deformation of the 1st seal | sticker part 10, the 2nd seal | sticker part 11 is provided and the insertion position of the cylindrical part 20 is controlled, but a seal member If excessive elastic deformation of the first seal portion 10 can be suppressed by changing the material and shape of the first seal portion 10, the second seal portion 11 is omitted as shown in the example shown in FIG. You may make it seal between 20 taper surfaces 20b. As described above, air leakage can be prevented without providing the second seal portion 11 as long as the tapered surface 20 b is reliably sealed.

  Further, the seal device for leak test according to the present invention is not limited to the seal device that seals the opening of the cylindrical portion as described above, but also to the seal device included in the fluid supply device that supplies the fluid for leak test. It is applicable. That is, also in the connection part of the fluid supply device connected to the cylindrical part of the workpiece, by providing a seal member (first seal part) in contact with the tapered surface of the cylindrical part, the tapered surface is the same as in the above embodiment. Good adhesion can be obtained between the seal member and the seal member, and air leakage from the seal portion can be reliably prevented.

DESCRIPTION OF SYMBOLS 1 Sealing device 2 Outer cylinder 3 Inner cylinder 4 Valve body 5 Valve seat 6 1st spring 7 2nd spring 8 Lock ball 9 Seal member 10 1st seal part 11 2nd seal part 20 Cylindrical part 20a Open end surface 20b Tapered surface

Claims (1)

A seal device for a leak test attached to a cylindrical portion having a tapered surface on the outer peripheral surface, the diameter of which decreases toward the opening end surface,
A leak test seal device comprising a seal member pressed against the taper surface and in an annular contact in the circumferential direction.

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