JP2004354152A - Leak tester holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leak tester holder which can reduce the time and the burden for forming a groove part in a work seal base. <P>SOLUTION: The leak tester holder 1 is provided with the work seal base 10 consisting of three members of a substrate 11, a first plate member 12 in which a hole part 12a having a shape along the outer edge of the work 2 is formed, and a second plate member 13 having a similar shape smaller than that of the hole part 12a. When the first plate member 12 and the second plate member 13 are mounted and fixed on the substrate 11, the groove part 10a is formed by the substrate 11, the inner circumferential surface 12A of the hole part 12a of the first plate member 12, and the outer circumferential surface 13B of the second plate member 13. The first plate member 12 and the second plate member 13 are manufactured by performing a wire cut electrical discharge machining for a stainless steel 2B finished plate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a jig for a leak tester, and more particularly to a jig for a leak tester for examining the presence or absence of a leak caused by the formation of a cavity in a work (cast product).
[0002]
[Prior art]
A work (cast product) may have a cavity. As a method of inspecting whether or not cavities are generated in the work, a closed space is defined by being surrounded by the work and the leak tester jig using a leak tester jig, and the closed space is defined as 2. Description of the Related Art A method of inspecting under pressure has been conventionally known.
[0003]
Japanese Patent Laid-Open Publication No. 2000-74777 discloses a leak tester jig and a leak inspection method having such a configuration. The leak tester jig includes a work seal base on which a work is placed and an upper mold. The upper die is placed opposite to the work seal base, and can be separated and approached relatively to the work seal base, and the work placed on the work seal base can be pressed against the work seal base. is there. A groove is formed along the outer edge of the work at a position on the work seal base opposite to the outer edge of the work placed on the work seal base. An O-ring as a seal member is fitted into the groove. When the work is placed on the work seal base, the outer edge of the work comes into contact with the O-ring.
[0004]
In general, such a groove has a substantially U-shaped cross section that opens toward the upper mold, and one of the side walls defining the groove is provided to prevent the O-ring from coming off. An inclined surface is formed in which the width of the groove gradually decreases from the bottom surface of the groove toward the opening.
[0005]
[Patent Document 1]
JP-A-2000-74777 (pages 2 to 4, FIG. 1)
[0006]
[Problems to be solved by the invention]
The groove portion of the work seal base constituting the jig for the leak tester is generally formed by end milling. However, as described above, one of the side walls defining the groove portion has the O-ring. In order to provide such an inclined surface, it is necessary to replace the blade in end milling.
[0007]
Further, in the end milling, the cut surface on which the groove is formed becomes rough. Therefore, it is necessary to manually polish the cut surface with an oil whetstone after the end milling. For these reasons, it takes time and effort to form the groove in the work seal base.
[0008]
Then, an object of the present invention is to provide a jig for a leak tester which can reduce time and labor for forming a groove in a work seal base.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a work seal base in which a groove 10a into which a seal member 14 is fitted is formed, and an outer edge of the work 2 abuts on the seal member 14 and the work 2 is placed. The work seal base 10 has an upper die 20 for pressing the work 2 placed on the work seal base 10 against the work seal base 10. The outer edge of the work 2 is sealed by the seal member 14 by pressing the work 2 on the base 10, and the pressure of the work internal space 2 a defined by the work 2 and the work seal base 10 is set to the outside of the work 2. As different values, in the leak tester jig 1 for detecting gas leakage between the work internal space 2a and the outside of the work 2, the work seal base 10 includes a substantially plate-shaped substrate 11, It is placed and fixed on the substrate 11 and The first plate member 12 having a hole 12a formed along the outer edge of the hole 2 has a similar shape smaller than the hole 12a, and the first plate member 12 is formed on the substrate 11 in a positional relationship corresponding to the hole 12a. A second plate member 13 mounted and fixed in the hole 12a; an inner peripheral surface 12A of the substrate 11 and the hole 12a of the first plate member 12; and an outer peripheral surface of the second plate member 13 13B defines the groove 10a in which the seal member 14 fits, and at least one of the inner peripheral surface 12A and the outer peripheral surface 13B faces the direction in which the width of the groove 10a is separated from the substrate 11. The jig 1 for a leak tester having an inclined surface which becomes smaller and has a function of preventing the sealing member 14 from coming off is provided.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
A jig for a leak tester according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the leak tester jig 1 includes a work seal base 10 and an upper die 20. The work 2 (cast product) is placed on the work seal base 10. The upper die 20 is disposed to face the work seal base 10 and can be separated and approached relatively with respect to the work seal base 10. The upper mold 20 is configured to transfer the work 2 placed on the work seal base 10 to the work seal base 10. The table 10 can be pressed.
[0011]
The work 2 on which the leak inspection method using the jig 1 for a leak tester is performed has a substantially square outer edge as shown in FIG. 2 and a hollow portion as shown in FIG. Domed. The outer edge portion forms a flange-like portion 2A as shown in FIG.
[0012]
The work seal base 10 includes a substantially plate-shaped substrate 11 made of an aluminum alloy, and a first plate member 12 and a second plate member 13 formed by processing a stainless 2B finished plate. The first plate member 12 is a through-hole 12a which is a through-hole shaped along the outer edge of the work 2, that is, a through-hole having a similar shape smaller than the outer periphery 2B of the flange-shaped portion 2A forming the outer edge of the work 2. A hole 12a (FIG. 2) is formed. The outer periphery 13 </ b> A (FIG. 2) of the second plate member 13 has a similar shape smaller than the hole 12 a formed in the first plate member 12. The formation of the hole 12a of the first plate member 12 and the processing of the outer periphery 13A of the second plate member 13 are performed by performing wire cut electric discharge machining on a stainless 2B finished plate, and the first plate member 12 and the second plate The member 13 is manufactured.
[0013]
The first plate member 12 and the second plate member 13 are respectively mounted and fixed on the substrate 11. As shown in FIG. 2, the second plate member 13 has a hole 12a of the first plate member 12 in a hole 12a of the first plate member 12 mounted and fixed on the substrate 11 (FIG. 1). The outer periphery 13 </ b> A of the second plate member 13 is arranged in a positional relationship that matches the shape, and is fixed to the substrate 11. The first plate member 12 and the second plate member 13 are fixed to the substrate 11 by screw members (not shown).
[0014]
Since the outer edge of the second plate member 13 has a similar shape smaller than the hole 12a formed in the first plate member 12 as described above, the first plate member 12 and the second plate member 13 have the same shape. Is formed between them. Therefore, when the first plate member 12 and the second plate member 13 are mounted and fixed on the substrate 11, as shown in FIG. A groove 10a is formed by the peripheral surface 12A and the outer peripheral surface 13B of the second plate member 13. As shown in FIGS. 1 and 3, the groove 10 a has a substantially “U” -shaped cross section that opens toward the upper mold 20, and an O-ring 14 serving as a seal member is fitted therein. The O-ring 14 fitted into the groove 10a abuts on the flange-shaped portion 2A that forms the outer edge of the work 2 placed on the work seal base 10. The O-ring 14 is made of resin or rubber, and prevents air from leaking from between the flange-shaped portion 2A and the work seal base 10.
[0015]
As shown in FIG. 3, the inner peripheral surface 12A of the hole 12a of the first plate member 12 that defines the groove 10a is perpendicular to the surface of the substrate 11, but the second surface that defines the groove 10a. The outer peripheral surface 13 </ b> B of the plate member 13 is not perpendicular to the surface of the substrate 11, but is an inclined surface in which the width of the groove 10 a gradually decreases in the direction away from the substrate 11. The outer peripheral surface 13B of the second plate member 13 forming an inclined surface serves as a stopper for preventing the O-ring 14 fitted in the groove 10a from falling out of the groove 10a.
[0016]
As shown in FIG. 2, through-holes 11a and 13a are formed in the central axis position of the substrate 11 and the central axis position of the second plate member 13 in a coaxial positional relationship with each other. As shown in FIG. 1, a joint 15 is provided at the open end of the through hole 11a that opens on the side opposite to the side where the second plate member 13 of the substrate 11 is mounted and fixed. One end of the hose 3 is connected to 15. The other end of the hose 3 is connected to a compressor 4 for supplying air to a work internal space 2 a described later via the hose 3. Accordingly, the compressor 4 communicates with the work internal space 2 a via the hose 3, a leak tester 5 described below, and the joint 15.
[0017]
A leak tester 5 is connected to a position halfway between one end and the other end of the hose 3. The leak tester 5 is provided with a valve (not shown) to supply air from the compressor 4 to the work internal space 2a by turning the valve on and to stop supplying air by turning the valve off. It is configured to be able to.
[0018]
The upper die 20 includes a substantially plate-shaped upper die main body 21 and four pins 22. The upper die body 21 is arranged in parallel with the substrate 11 of the work seal base 10, and four pins 22 are provided extending from the upper die body 21 in the direction of the work seal base 10.
The upper die 20 is provided with a hydraulic or pneumatic cylinder (not shown), and the upper die 20 approaches and separates from the work seal base 10 by driving the cylinder (not shown). In FIG. 1, only two of the four pins 22 appear.
[0019]
The four pins 22 are formed such that the free ends of the four pins 22 when the upper mold 20 is moved closer to the work seal base 10 have an outer edge of the work 2 having a substantially square shape as shown in FIG. The work 2 is disposed at a predetermined position on the upper die 20 so that the work 2 can be pressed against the work seal base 10 by contacting the four corners of the flange-shaped portion 2A. When the pin 22 presses the flange-shaped portion 2A of the work 2 against the O-ring 14 of the work seal base 10, the work 2 is fixed to the work seal base 10, and is defined by the work 2 and the work seal base 10. The work internal space 2a to be sealed is made a closed space to ensure sealing performance.
[0020]
Since the work seal base 10 is constituted by the three members of the substrate 11, the first plate member 12, and the second plate member 13, the first plate is formed by performing the wire cut electric discharge machining without performing the end milling. By manufacturing the member 12 and the second plate member 13 and mounting and fixing the first plate member 12 and the second plate member 13 on the substrate 11, it is possible to form the groove 10 a into which the O-ring 14 is fitted. it can. For this reason, the groove 10a can be easily formed without performing the replacement work of the blade in the conventional end mill processing, and time and labor for forming the groove 10a can be saved.
[0021]
Further, since the substrate 11 does not directly contact the work 2, the work seal base 10 is made such that the first plate member 12 and the second plate member 13 are made of stainless steel and the substrate 11 is made of an aluminum alloy. Of the work seal base 10 can be reduced in weight. For this reason, the moving operation when moving the work seal base 10 to another place can be facilitated.
[0022]
Next, an assembly process for assembling the work seal base 10 will be described. In the assembling step, first, the first plate member 12 and the second plate member 13 are mounted and fixed on the substrate 11 by screw members (not shown). Next, the O-ring 14 is fitted into the groove 10a.
[0023]
Next, a leak inspection method will be described. In the leak inspection method, first, a sealing step is performed. In the sealing step, first, the work 2 is placed on the work seal base 10 of the leak tester jig 1 such that the flange-shaped portion 2A forming the outer edge of the work 2 comes into contact with the O-ring 14. Next, the upper mold 20 is relatively approached to the work seal base 10, the pins 22 of the upper mold 20 are brought into contact with the flange-shaped portions 2 </ b> A of the work 2, and the work 2 is moved by the upper mold 20. The outer edge of the work 2 is sealed with the O-ring 14 by pressing against the seal base 10.
[0024]
Next, a pressing step is performed. In the pressurizing step, first, the valve of the leak tester 5 is turned on, and air is supplied from the compressor 4 to the work internal space 2a. Next, when it is confirmed by the leak tester 5 that the air pressure in the work internal space 2a has been increased to a desired value different from the air pressure outside the work 2, the compressor 4 valve is turned off, The supply of air to the internal space 2a is stopped.
[0025]
Next, an inspection process is performed. In the inspection process, the leak tester 5 measures a change in atmospheric pressure in the work internal space 2a. When the air pressure is decreasing at a predetermined reduction speed or more, it is determined that a cavity is formed in the work 2 and gas leaks between the work internal space 2a and the outside of the work 2. When the air pressure is decreasing at a speed lower than the predetermined decreasing speed, or when the atmospheric pressure is not decreasing, no porosity is formed in the work 2 and there is no gas leakage between the work internal space 2a and the outside of the work 2. Judge. The leak inspection method is performed through the above steps.
[0026]
The leak tester jig according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, in the present embodiment, the outer peripheral surface 13B of the second plate member 13 defining the groove 10a is an inclined surface in which the width of the groove 10a gradually decreases in the direction away from the substrate 11. Instead of the outer peripheral surface of the second plate member, the inner peripheral surface of the hole of the first plate member may be an inclined surface in which the width of the groove gradually decreases in the direction away from the substrate. Further, both the inner peripheral surface of the hole of the first plate member and the outer peripheral surface of the second plate member may be such inclined surfaces.
[0027]
Further, the substrate 11 of the work seal base 10 is made of an aluminum alloy, but may be made of a stainless steel 2B finished plate.
[0028]
Although the number of pins 22 is four, it is not limited to this number. In addition, the pin 22 comes into contact with the four corners of the flange-shaped portion 2A forming the outer edge of the substantially square work 2, and presses the work 2 against the work seal base 10. Parts other than the four corners may be pressed. For example, the top of the dome-shaped central portion may be pressed. Therefore, the outer edge portion of the work does not have to be a flange portion.
[0029]
When a cast hole is formed in the dome-shaped side surface of the work or the like, a seal member may be fitted into the cast hole to seal the work internal space.
[0030]
The work internal space 2a is supplied with air and pressurized, but is decompressed to a desired pressure, and then measures how the air pressure in the work internal space 2a changes to measure the work leak. May be performed.
[0031]
【The invention's effect】
According to the jig for a leak tester according to claim 1, the work seal base has a substantially plate-shaped substrate and a first plate formed and fixed on the substrate and having a hole formed along the outer edge of the work. The end milling process is made up of three members: a member and a second plate member that has a similar shape smaller than the hole and is placed and fixed in the hole on the substrate in a positional relationship corresponding to the hole. The first plate member and the second plate member are manufactured by performing wire cut electric discharge machining without performing the above, and the seal member is fitted by mounting and fixing the first plate member and the second plate member on the substrate. Grooves for mating can be formed. Therefore, the groove can be easily formed, and the time and labor required for manufacturing the leak tester jig used in the leak inspection method can be saved.
[0032]
Further, since the first plate member and the second plate member and the substrate can be made of different materials, for example, the substrate, which is a part of the work seal base, is made of a light material, and the entire work seal base is formed. Can be reduced in weight. For this reason, the moving operation when moving the work seal base to another place can be facilitated.
[0033]
Further, at least one of the inner peripheral surface of the hole of the first plate member defining the groove and the outer peripheral surface of the second plate member becomes smaller in the direction in which the groove is separated from the substrate, and the sealing member is removed. Since the sealing member has the inclined surface, the sealing member can be prevented from coming off the groove.
[Brief description of the drawings]
FIG. 1 is a partial sectional view showing an entire apparatus for performing a leak tester jig according to an embodiment of the present invention.
FIG. 2 is a plan view showing a jig for a leak tester according to the embodiment of the present invention.
FIG. 3 is a sectional view of a portion surrounded by a line III in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Leak tester jig 2 Work 2a Work internal space 10 Work seal base 10a Groove 11 Substrate 12 First plate member 12A Inner peripheral surface 12a Hole 13 Second plate member 13A Outer periphery 13B Outer peripheral surface 14 O-ring 20 Upper die

Claims (1)

A groove portion in which the seal member is fitted is formed, and a work seal base on which the work is placed with the outer edge of the work abutting the seal member,
An upper mold that presses the work placed on the work seal base against the work seal base,
The work is pressed against the work seal base by the upper mold to seal the outer edge of the work with the seal member, and the pressure of the work internal space defined by the work and the work seal base is changed to the work pressure. In a leak tester jig for detecting gas leakage between the inside of the work and the outside of the work as a value different from the outside of the work, the work seal base includes a substantially plate-shaped substrate, A first plate member mounted and fixed on the substrate and formed with a hole having a shape along the outer edge of the work, and a similar shape smaller than the hole and formed on the substrate in a positional relationship corresponding to the hole; A second plate member placed and fixed in the hole portion of
The substrate, the inner peripheral surface of the hole of the first plate member, and the outer peripheral surface of the second plate member define the groove in which the seal member is fitted, and the inner peripheral surface, the outer peripheral surface, At least one of the jigs for a leak tester, wherein the width of the groove decreases in a direction away from the substrate and has an inclined surface for preventing the sealing member from coming off.

Images