JP3416005B2 - Leak test device, sealing method and sealing structure - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a leak test device, a sealing method, and a sealing structure.

[0002]

2. Description of the Related Art A sealing device is used to prevent leakage of gas or liquid or intrusion of foreign matter from the outside. Among these, as a device that performs sealing by using direct contact, there is one that uses a ring-shaped sealing member (O-ring or the like). For example, an O-ring is a ring-shaped member mainly made of synthetic rubber and having a circular cross section, and is easily widely attached and has excellent sealing properties, and is therefore widely used in general. The O-ring is compressed and attached to a groove having a rectangular cross section with an appropriate squeezing margin, and due to the repulsive force of the rubber itself, the O-ring is pressed against the wall surface to perform a sealing action.

Although a sealed structure is required when performing a leak test, an O-ring is often used here as well.
For example, when performing a leak test on a product having a cylindrical portion, the following leak test apparatus is used. The leak tester consists of a supply part that supplies helium, a connection part where one end is connected to the supply part and the other end is connected to the product in a sealed state, a storage case that stores the product, and the periphery of the product in the storage case. And a detector for detecting helium leaking from the inside of the product into the storage case. In such a leak test device, the O-ring is used between the product and the connection part.

When performing a leak test on a large number of products using the leak test apparatus as described above, when the test for one product is completed, the product is removed from the connection portion and the next product is connected. That is, connection and disconnection of the connection part and the products are repeated for the number of products.

[0005]

Conventionally, an O-ring mounting groove is formed in a connecting portion of a leak test device, and a cylindrical portion of a product is inserted with the O-ring set in the groove to mount an O-ring in the connecting portion. An O-ring is compression-fitted between the groove and the product for sealing. Here, the inner diameter of the O-ring is smaller than the outer diameter of the cylindrical portion of the product by the crushing margin of the O-ring. Therefore, when the product is inserted, the corner of the end surface of the cylindrical portion of the product may hit the inner peripheral portion of the O-ring, which may damage the O-ring. Normally, the end surface of the cylindrical portion of the product is chamfered to prevent damage, but the connection and disconnection are repeated for each product, so the sealing performance of the O-ring deteriorates. Therefore, in the leak test, the O-ring is replaced with a new one every tens of times. In addition, some products have notches on the end faces and few chamfers. In such a case, the O-ring must be replaced more frequently.

SUMMARY OF THE INVENTION An object of the present invention is to suppress damage to a sealing member such as an O-ring, extend the life of the sealing member, and reduce the number of man-hours for replacing the sealing member.

[0007]

A leak test apparatus according to a first aspect of the present invention is a leak test apparatus used for a leak test of a product, comprising a connecting member, a seal member, and a supply means. The connection member has an insertion portion, a seal mounting portion, and a relief portion. The insertion part is formed in a tubular shape, and a part of the product is inserted therein. The seal mounting portion is formed on one end side of the insertion portion and has a cylindrical seal surface. The escape portion has a tapered surface, and the tapered surface is formed so that the diameter gradually increases from the end of the seal mounting portion. The seal member is mounted on the seal mounting portion, and is pressure-contact mounted between the sealing surface of the seal mounting portion and the product mounted on the insertion portion. The supply means is connected to the insertion part and supplies gas or fluid to the product mounted in the insertion part.

When performing a leak test, first, a part of the product is inserted into the insertion portion of the connecting member. In this state, a part of the product and the connecting member are sealed by the sealing member. Then, in the state where the gas or the liquid is supplied to the product by the supply means, the gas or the liquid leaking from the inside of the product is detected or the change in the pressure inside the product is checked. Here, the gap between the seal surface of the seal mounting part and the product is set to the dimension obtained by subtracting the crushing margin from the cross-sectional size of the seal member, but the gap between the relief part and the product is larger than this size. Has become. Therefore, if the seal member is arranged in the escape portion when the product is inserted into the connecting member, the contact of the end surface of the product with the seal member at the time of inserting the product can be relaxed, or the end surface of the product can be reduced. It is possible to avoid contact with the seal member. Thereby, damage to the seal member can be suppressed and the life of the seal member can be extended.

A leak test apparatus according to a second aspect is the leak test apparatus according to the first aspect, further comprising a seal member moving means. The seal member moving means is
The seal member is moved from the escape portion to the seal mounting portion while a part of the product is inserted into the insertion portion. Here, after the product is inserted into the connecting member, the seal member can be reliably moved from the escape portion to the seal mounting portion and the seal member can be compressed and mounted, so that sealing can be reliably performed.

According to a third aspect of the present invention, there is provided the leak test apparatus according to the second aspect, wherein the seal member moving means has a seal member contact portion. The seal member contact portion can be inserted into the clearance portion and contacts the seal member. Further, the seal member contact portion is relatively movable with respect to the connection member and is detachable. Here, since the seal member contact portion is relatively movable with respect to the connection member and detachable, it is easy to replace the seal member when the seal member is consumed.

A leak test apparatus according to a fourth aspect is the leak test apparatus according to any one of the first to third aspects, further comprising a storage case, a vacuum evacuation means, and a detection means. The storage case stores the product and forms a sealed space with the product. The vacuum evacuation unit is a unit for exhausting the sealed space in the storage case to create a vacuum in the sealed space. The detection means is means for detecting gas or fluid leaking from the product into the sealed space inside the storage case.

When performing a leak test using this leak test apparatus, first, the product is set in the storage case and connected to the connecting member in a sealed state. Then, a suitable gas or fluid is supplied to the inside of the product by the supply means. And
The inside of the storage case is evacuated, and the gas or fluid leaking from the inside of the product is measured by the detection means. The quality of the product is judged based on the leak amount detected by measuring for a predetermined time.

According to a fifth aspect of the present invention, there is provided a sealing method, wherein the first member is formed in a tubular shape and has an insertion portion, a seal mounting portion and a clearance portion, and a second member inserted into the insertion portion of the first member. It is a sealing method for sealing and using a ring-shaped seal member, and includes a first step and a second step. The seal mounting portion of the first member is formed on one end side of the insertion portion,
It has a cylindrical sealing surface. The escape portion of the first member is
It has a tapered surface formed so that the diameter gradually increases from the end of the seal mounting portion. In the first step, the seal member is arranged in the relief portion of the first member. In the second step, while inserting a part of the second member into the insertion portion of the first member,
The seal member and the seal surface of the seal mounting portion of the first member and the second member
Pressure contact and close contact with the member.

The gap between the seal surface of the seal mounting portion and the product is set to a dimension obtained by subtracting the crushing margin from the cross sectional dimension of the seal member, but the gap between the escape portion and the product is larger than this dimension. . Here, when the second member is inserted into the first member, the seal member is arranged in the escape portion, and after the end surface of the second member has passed the inner peripheral portion of the seal member, the seal member is attached to the escape portion with the seal. It can be transferred to a part and sealed. By doing this, it is possible to reduce the contact of the end surface of the product with the seal member when inserting the product,
Alternatively, contact of the end surface of the product with the seal member can be avoided. Thereby, damage to the seal member can be suppressed and the life of the seal member can be extended.

The sealing method according to claim 6 is the sealing method according to claim 5, wherein the second step includes a step of moving the seal member from the escape portion to the seal mounting portion.
Here, the seal member is reliably moved from the escape portion to the seal mounting portion. The sealing structure according to claim 7 is 2
A sealing structure for sealing one member includes a first member, a second member, and a sealing member. The first member is formed in a tubular shape, and has an insertion portion, a seal mounting portion, and a relief portion. The seal mounting portion is formed on one end side of the insertion portion and has a cylindrical sealing surface. The relief portion has a tapered surface formed so that the diameter gradually increases from the end of the seal mounting portion. Second
At least a part of the member is inserted into the insertion portion of the first member. The seal member is mounted on the seal mounting portion, and is pressure-contact mounted between the sealing surface of the seal mounting portion and the second member mounted on the insertion portion.

The sealing structure according to claim 8 is the sealing structure according to claim 7, further comprising a seal member moving means. The seal member moving means moves the seal member from the escape portion to the seal mounting portion in a state where at least a part of the second member is inserted into the insertion portion of the first member.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a leak test apparatus 1 in which an embodiment of the present invention is adopted. The leak test apparatus 1 is used for a leak test of a mass-produced product (torque converter 50 shown in FIG. 1). The torque converter 50 has a tubular portion 50a, and the inside thereof is hermetically sealed when the end portion of the tubular portion 50a is closed. FIG. 2 is an enlarged view of the connection portion between the leak test apparatus 1 and the torque converter 50 that is the test object.
The state before sealing and the state after sealing of 50 are separately shown on the right side and the left side.

As shown in FIG. 1, the leak test apparatus 1 includes a main body 2, a helium supply apparatus A, and a vacuum exhaust apparatus B.
And a helium detector C and a purge dry air supply device D. The main body 2 has a connecting member 3, an O-ring moving mechanism 4, a storage case 5, and an O-ring 10, and creates a sealed space 90 that is hermetically sealed around the torque converter 50. The O-ring 10 has an inner diameter substantially equal to the outer diameter of the tubular portion 50a of the torque converter 50.

The connecting member 3 is a disc-shaped member through which the steel pipe 22 penetrates at the center, and is a cylindrical insertion portion 3 facing downward.
f (see FIG. 2) extends. The inner diameter of the insertion portion 3f is slightly larger than the outer diameter of the tubular portion 50a, and therefore O
It is slightly larger than the inner diameter of the ring 10. As shown in FIG. 2, the insertion portion 3f is provided below the insertion portion 3f of the connection member 3.
A seal mounting portion 3b, which is a cylindrical cavity having a sealing surface 3a having a diameter larger than the inner diameter of the seal mounting portion 3b, is formed. Further, at the lower portion thereof, a tapered surface 3c formed so that the diameter gradually increases from the lower end of the sealing surface 3a, and a peripheral surface 3 having the same diameter as the diameter from the lower end of the tapered surface 3c to the lower end of the tapered surface 3c.
An escape portion 3e which is a cavity having d and is formed.
The diameter of the seal surface 3a of the seal mounting portion 3b is set to a dimension obtained by adding the cross-sectional dimension obtained by subtracting the crushing margin of the O-ring 10 to the outer diameter of the tubular portion 50a of the torque converter 50. The diameter of the lower end of the tapered surface 3c, that is, the diameter of the peripheral surface 3d is set to be larger than the outer diameter of the O-ring 10.

The O-ring moving mechanism 4 is composed of an O-ring contact member 6 and a product contact member 7. The O-ring contact member 6 includes an inner cylindrical portion 6b on the inner peripheral side and an outer cylindrical portion 6c on the outer peripheral side.
It is a shape in which and are connected by an annular disc portion 6d at the lower end. The outer cylindrical portion 6c has an inner diameter substantially equal to the outer diameter of the insertion portion 3f of the connection member 3, and has a plurality of circumferentially long slots 6a in the axial direction.
Is provided. The O-ring moving mechanism 4 has the slot 6
A bolt 30 penetrating a and fixed to the insertion portion 3f is coupled to the connection member 3 so as to be relatively movable in the axial direction. The O-ring moving mechanism 4 can be removed from the connecting member 3 by removing the bolt 30.
The inner cylindrical portion 6b supports the lower portion of the O-ring 10 with the O-ring moving mechanism 4 attached to the connecting member 3. The inner diameter of the inner cylindrical portion 6b is equal to the inner diameter of the insertion portion 3f, and the outer diameter is smaller than the diameter of the sealing surface 3a.

The product contact member 7 is fixed to the lower surface of the annular disc portion 6d of the O-ring contact member 6 at several positions in the circumferential direction. The product contact member 7 is composed of a screw and a cylinder having a screw hole, and its height can be adjusted. The storage case 5 has a box-shaped cover portion 5 whose lower surface is open.
a and a product installation table 5b on which the product is placed. The steel pipe 21 penetrates the lower part of the cover portion 5a, and the steel pipe 23 penetrates the upper part on the opposite side. In addition, an opening 5c is provided in the upper portion of the cover portion 5a for inserting the insertion portion 3f of the connecting member 3 having the O-ring moving mechanism 4 attached thereto.

A helium supply device A, a vacuum exhaust device B, a helium detector C, and a dry air supply device D are connected to the main body 2 having the above-mentioned structure via a pipe. The helium supply device A is connected to the steel pipe 22 penetrating the connection member 3 with the valves 32 and 33 interposed therebetween. The vacuum evacuation device B is branched and connected from a pipe extending from the steel pipe 23 penetrating the storage case 5 to the diffusion valve 34.

The helium detector C, like the vacuum exhaust device B, is branched and connected from a pipe extending to the diffusion valve 34. The dry air supply device D is connected to the steel pipe 21 penetrating the storage case 5 with the valve 31 interposed therebetween. Next, the procedure of the leak test will be described.

First, the torque converter 50 to be tested is set on the product installation table 5b, and the cover 5a is placed thereon. A seal member such as packing is attached between the product installation table 5b and the cover 5a to seal the gap between them. Then, the O-ring moving mechanism 4 is inserted into the insertion portion 3f of the connecting member 3 from the opening 5c of the cover 5a. The O-ring 10 is previously provided in the connecting member 3 and the escape portion 3 is provided.
The O-ring moving mechanism 4 is attached by the bolt 30 in the state of being placed at e (see the right side of FIG. 2). Further, the height of the product contact member 7 of the O-ring moving mechanism 4 is as follows when the connecting member 3 is set in the storage case 5 as shown in FIG.
The O-ring 10 is adjusted so as to come to the position of the seal mounting portion 3b.

When the connecting member 3 is inserted into the housing case 5, as shown on the right side of FIG. 2, the tubular portion 50a of the torque converter 50 is relatively inserted into the connecting member 3, and first the product contact member 7 is inserted. The lower surface of the abuts on the torque converter 50.
Here, since the diameter of the peripheral surface 3d of the escape portion 3e is set to be larger than the outer diameter of the O-ring 10 and the O-ring 10 is in a free state, the corner of the end surface of the tubular portion 50a contacts the O-ring 10. It does not hit at an angle. Therefore, compared to the case where the O-ring is set in the O-ring mounting groove as in the related art, the O-angle at the corner of the end surface of the tubular portion 50a is increased.
The angle of contact with the ring 10 is relaxed and damage due to contact is suppressed.

When further inserted, the O-ring moving mechanism 4 moves relative to the connecting member 3, and the inner cylindrical portion 6b of the O-ring abutting member 6 moves the O-ring 10 from the escape portion 3e to the seal mounting portion. Move relatively to 3b. Here, the O-ring 10 is in a compressed state between the seal surface 3a of the seal mounting portion 3b and the tubular portion 50a of the torque converter 50, and seals the insertion portion 3f and the tubular portion 50a.

When the torque converter 50 and the connecting member 3 are sealed in this way, as shown in FIG. 1, a space surrounded by the housing case 5, the connecting member 3 and the torque converter 50 (sealed space 90). Is sealed. The space between the storage case 5 and the connection member 3 is sealed with a sealing member such as packing. Next, after the dry air supply device D is operated to purge the sealed space 90, the valve 31
Then, the diffusion valve 34 is closed and the vacuum exhaust device B is operated. When the sealed space 90 reaches a predetermined vacuum degree, the helium supply device A supplies helium to the inside of the torque converter 50, and the helium detector C detects helium leaking from the inside of the torque converter 50 to the sealed space 90. If the predetermined helium is not detected at the predetermined time, the torque converter 50 is considered to have passed the leak test.

When one test is completed, the connecting member 3 with the O-ring moving mechanism 4 and the cover 5a are removed, the next torque converter 50 is set, and the test is repeated in the same procedure. If the O-ring 10 is consumed during repeated tests, the O-ring moving mechanism 4 is removed from the connecting member 3 and the O-ring 10 is replaced. Here, as described above, the torque converter 50 is different from the conventional one.
Since the O-ring is prevented from being damaged during connection between the O-ring 10 and the connecting member 3, the life of the O-ring 10 is extended and the number of times the O-ring 10 is replaced is reduced. O-ring 1 like this
By reducing the number of man-hours for the replacement work of 0, the time efficiency of the leak test is improved. In particular, when the end surface shape of the tubular portion 50a of the torque converter 50 has a cutout portion or when the corner of the end surface of the tubular portion 50a is chamfered,
The structure of the present invention, which can avoid the angular contact between this portion and the O-ring 10, works effectively for extending the life of the O-ring.

[0029]

According to the present invention, damage to the seal member can be suppressed by setting the seal member before sealing in the clearance portion which is larger in size than the seal mounting portion which is displaced from the seal mounting portion. Its lifespan is extended.

[Brief description of drawings]

FIG. 1 is a leak test apparatus to which an embodiment of the present invention is applied.

FIG. 2 is an enlarged view of a connection portion between a leak test device and a device under test.

[Explanation of symbols]

1 Leak test equipment 3 connection members 3a Sealing surface 3b Seal mounting part 3c Tapered surface 3e escape part 3f insertion part 4 O-ring moving means 5 storage cases 6 O-ring contact member 7 Product contact member 10 O-ring 50 torque converter A Helium supply device B vacuum exhaust system C Helium detector D Dry air supply device

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Claims (8)

(57) [Claims] 1. A leak test apparatus used for a leak test of a product, comprising: an insertion part formed in a cylindrical shape, into which a part of the product is inserted; and a cylindrical shape formed at one end side of the insertion part . A connecting member having a seal mounting portion having a sealing surface, and a relief portion having a tapered surface formed so that the diameter gradually increases from the end of the seal mounting portion; A seal member press-fitted between the seal surface of the seal mounting portion and a product mounted in the insertion portion, and a supply connected to the insertion portion and supplying gas or fluid to the product mounted in the insertion portion Means and a leak test device comprising. 2. The seal member moving means for moving the seal member from the escape portion to the seal mounting portion in a state in which a part of the product is inserted into the insertion portion, further comprising: Leak test equipment. 3. The seal member moving means has a seal member contact portion that can be inserted into the escape portion and abuts against the seal member, and the seal member contact portion is opposed to the connection member. The movable and removable structure.
Leak test device described in. 4. A storage case for storing the product and forming a hermetically sealed space between the product and the product, a vacuum evacuation unit for evacuating the sealed space in the storage case, The leak test apparatus according to any one of claims 1 to 3, further comprising: a detection unit that detects a gas or a fluid leaking into a sealed space inside the storage case. 5. The first member is formed in a tubular shape, and includes an insertion portion, a seal mounting portion having a cylindrical sealing surface formed on one end side of the insertion portion, and an end portion of the seal mounting portion. A ring-shaped seal member is used for the first member and the second member that is inserted into the insertion portion of the first member. A sealing method for sealing by means of a first step of arranging a seal member in an escape portion of the first member, and inserting a part of the second member into an insertion portion of the first member, and A second step of bringing a sealing member into pressure contact with the sealing surface of the seal mounting portion and the second member, the sealing method comprising: 6. The sealing method according to claim 5, wherein the second step includes a step of moving the seal member from the escape portion to the seal mounting portion. 7. A sealing structure for sealing two members, which is formed in a tubular shape and has an insertion portion and a cylindrical sealing surface formed at one end side of the insertion portion. And a first member having a relief portion having a tapered surface formed so that the diameter gradually increases from the end portion of the seal mounting portion, and at least a part is inserted into the insertion portion of the first member. A sealing structure comprising: a second member; and a seal member that is mounted on the seal mounting portion and is pressure-contact mounted between a sealing surface of the seal mounting portion and the second member mounted on the insertion portion. 8. A seal member moving means for moving the seal member from the escape portion to the seal mounting portion in a state where at least a part of the second member is inserted into the insertion portion of the first member. The sealing structure according to claim 7, wherein