JPH02205739A - Apparatus and method for detecting leakage of fluid for cast product - Google Patents

Abstract

PURPOSE: To obtain an accurate detector for performing a test with high reproducibility by a structure wherein a probe gas is jetted into an annular chamber formed by hermetically sealed a cavity while surrounding a cast article. CONSTITUTION: In order to form an inner chamber 80 in the cavity of a cast article, the cavity is sealed hermetically by means of upper and lower platens 36, 40. In order to form an annular chamber (helium chamber) 84 around the inner chamber 80, the cast article is surrounded by a cup-type housing 90 having open bottom. In order to generate vacuum in the inner chamber 80, a vacuum line 30 is provided while communicating with the inner chamber 80. In order to jet a probe gas, i.e., helium, into the annular chamber 84, the housing 90 is provided with a helium supply port 52. Specified quantity of helium fed into the annular chamber 84 is then measured preliminarily by means of a mass spectrometer 60 and the vacuum in the inner chamber 80 is controlled by means of a lower vacuum valve 26 and a vacuum release valve 28. Leakage of the cast article is determined by detecting a sample mixed with leakage helium by means of the mass spectrometer 60.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION [Industrial Application] The present invention relates generally to leakage construction systems for cast metal articles against fluid leakage through a metal matrix, and more particularly to leakage construction systems for leakage construction of cast metal articles against fluid leakage through a metal matrix, and more particularly, to The present invention relates to a leak detection apparatus and method using a device that senses the presence of an inert probe gas passing into an interior chamber.

[Prior art]

In the field of vehicle manufacturing, most cars and trunks are equipped with drum wheels. Drum wheel suppliers are vehicle manufacturers or subcontractors who are required to provide wheels that meet certain industry specifications. One such specification is
Wheels installed on vehicles or supplied to wholesale subcontractors must not have any structural defects that would result in the leakage of pneumatic media. Even the slightest structural flaw can cause a very slow leak.
The symptoms appear only when the wheel is used. Standard warranties covering materials and workmanship oblige the manufacturer or subcontractor to repair or replace defective wheels, which may result in significant costs to the supplier in terms of shipping, labor, and materials, as well as to the customer. The trouble it causes is also obvious.

It is also necessary in other industries to test cast metal articles for fluid leakage. Conventional leak detection systems suffer from many problems.

[Summary of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved cast article leak detection device and leak detection method that has superior accuracy compared to comparable leak detection devices that have been used in the past.

Another object of the present invention is to provide an improved cast article leak detection system having a system of vacuum valves that are automatically activated in a timed sequence in response to multiple vacuum levels.

Yet another object of the present invention is to provide an improved drum wheel leak detection system that can reproducibly test a series of drum wheels of many sizes.

Another object of the present invention is to provide an improved cast article leak detection system that can simulate the forces that exist under normal operating conditions.

Another object of the present invention is to provide an improved cast article leak detection system that proactively measures the volume of probe gas for each article tested.

It is a further object of the present invention to provide an improved cast article leak detection system that is quick and reliable and avoids subjective analysis of test results.

[Detailed description of preferred embodiments]

A leak detection device, particularly for testing drum wheels for leaks, is shown in FIG. 1 and designated generally at 10. The leak detection system 10 includes a plurality of gauges: a vacuum rAJ gauge 12, a vacuum "B" gauge 14, a vacuum manifold 16, an upper vacuum valve 18, a sample isolation valve 20, a detection valve 22, a lower vacuum (main) valve 26, a vacuum Release valve 28, main vacuum line 30
and a vacuum suction line 32.

The detection device 10 further includes an outer chamber having an upper platen 36 with a plated upper sealing ring 38 (shown in FIG. 2) and a lower (table) platen 4o with a plated lower (table) sealing ring 42. 34,
A support platform 44, an upper support structure 45, a plurality of blow nozzles 46, a plurality of air cylinders 48 for elevating the outer chamber 34, an air cylinder 50 for raising and lowering the upper platen 36, a plurality of helium supply inlets 52, and gas Mass spectrometer 6 for testing air samples extracted from inside drum wheel 62, including vacuum line 54
0 is used with the detection device 10.

In FIGS. 2.3 and 4, a cross-section of the detection device 10 is shown, and also the outer chamber sealing ring TO.

The present invention embodies a leak detection device 10 that includes an outer chamber volume reduction disk 72 and a plurality of mechanical fasteners 74, which includes an upper platen 36 and a lower platen 40.
and engages an unmounted drum wheel (or tubular member) to form a hermetically sealed inner first chamber 80. The outer chamber 34 moves vertically along the air cylinder 48 and the volume reduction disk 72 is raised and lowered by the air cylinder 50. The volume reduction disk 72 is lowered to a rest position on the lower platen 36 at the appropriate time and then lowered until the outer chamber 34 is sealed onto the lower platen sealing ring 42. The outer chamber 34 surrounds the drum wheel 62 while the disk 72 reduces the volume of the outer chamber 34 to form an annular helium chamber 84 (see FIG. 4) surrounding the wheel 62 and the formed inner chamber 8o. do.

An annular helium chamber 84 is an upper portion of the outer chamber 34 that includes the volume bounded by the volume reduction disk 72, the lower platen 40, the outer chamber 34, and the portion of the wheel 62 located between the upper platen 36 and the lower platen 40. The volume of the space between the helium chamber 84 and the volume-reducing disk 72 (when the outer chamber 34 is in the lower position) is not included in the annular helium chamber 84; Multiple helium supply inlets 52 for delivery
Implemented by Inner chamber 80 is under vacuum and a sample of the atmosphere within wheel 62 is sampled by probe gas passing from helium chamber 84 through the structure of wheel 62 and into inner chamber 8 .
It will be analyzed to see if it has leaked to 0. Additionally, the detection apparatus 10 includes structure for storing, pre-measuring, delivering, displacing and evacuating the probe gas and cleaning the upper platen 36 from the probe gas via a plurality of blow nozzles 46.

In the following description, helium is used as a probe gas because the mass spectrometer, which is an analytical device, is sensitive to gas molecules. selected to act as a mixing element. Although helium is an inert gas, it can be ionized, while other more active gases (al! elements, nitrogen, hydrogen, carbon, etc.) exist naturally in mixtures.

In this preferred embodiment, support plant form 44 acts as a table that supports lower platen 40, wheel 62, and vacuum inlet line 32 extending from the wheel. The support plant form 44 is connected to the upper support structure 45
(shown in FIG. 1), which includes air cylinders 48, 50 used to guide the vertical movement of the outer chamber 34, the volume reduction disk 72, and the upper platen 36. It is intended to support the

However, the present invention is not limited to support platforms 44 and support structures 45 of the type used in this embodiment; it is important to note that support platforms 44 and support structures 45 may be used for leak detection. device 10
be able to keep enough space between them.

Air cylinder 50 includes a shaft 86 extending from upper support structure 45 toward support plant form 44 .

The shaft 86 is slidably attached to the support structure 45 by a pneumatic expansion device 88 (see FIG. 1) to permit selective vertical annular movement relative to the support plant form 44. , in this example a solenoid actuated pneumatic jack, but any conventional device may be used, such as an electric motor driven actuator. An upper platen 36 is mounted at the distal end of the shaft 86 (opposite the pneumatic expansion device 88) in threaded engagement with the shaft 86. For purposes of illustration and not necessarily limitation, upper platen 36 is a plate or disk approximately 2 feet (0.61 m) in diameter. In one embodiment, upper platen 36 is controlled by a solenoid actuated air cylinder 50 and seals the lumen of drum wheel 62. Air cylinder 50 has a standard four-way solenoid valve to introduce vertical movement within upper platen 36. Air cylinder 50 includes a single cylinder drive member that is electrically actuated and pneumatically driven.

A lower platen 40 is mounted on top of the support plant form 44 and is disposed opposite and generally parallel to the upper platen. Sealing rings 38 and 42 are attached to the inwardly facing surfaces of upper and lower platens 36 and 40. In this embodiment, sealing rings 38 and 42 preferably include an annular ring formed of an elastomeric material with a diameter sufficient to interface with wheel rim flange 82.
8 is attached coaxially to upper platen 3G by a plurality of fasteners 74.

In this embodiment, lower platen sealing ring 42 is not coupled to lower platen 40 using fasteners 74, although mechanical fastening means may also be used in other embodiments. When the upper platen 36 is moved by the shaft 86 into engagement with the wheel 62 mounted on the lower platen 40, an inner chamber 80 is created and bounded by the platens 36 and 40, the rim flange 82 of the wheel 62, and the bore. can be attached.

Also shown in FIGS. 2-4 is outer chamber 34, which is disposed generally coaxially with axis 86. FIG. The outer chamber 34 is slidably mounted on a pair of air cylinders 48 which receive control from a pneumatic jacking device 89 to control the outer chamber relative to the platen 36,40 and the support plant form 44. The outer chamber 34 includes a cup-shaped housing 90 having a cylindrical wall 92 forming an enclosing end 94 .

Axis 86 extends through housing 90 by a generally coaxial central hole 96 formed in encircling end 94 of cylindrical wall 92 . A pair of holes 97 are provided in the enclosing end 94 which permanently vent the housing 90 to the atmosphere and which allow the gas vacuum line 5
Provide passage for 4 people.

A pair of cylinders 48 are mounted on top of a cup-shaped housing 90, each cylinder 48 having one end thereof mounted to support structure 45 (see FIG. 1) and housing 90.
with an opposite second @ attached to the closed end 94 of 0;
Air cylinder 48 is an electrically actuated pneumatic device that moves housing 90 along axis 86 relative to upper platen 36 and support brat form 44 from the locked position shown in FIG. Selectively move to the rest position shown in the figure.

Downward movement of the housing 90 is facilitated by gravity. A cylindrical wall 92 extends downwardly from the periphery of the occlusion @ 94 of the housing 90 and generally vertically. Multiple gas inflow holes 10
0 is formed in the cylindrical wall 92 and the helium supply inlet 52
is communicated with an annular helium chamber 84.

Preferably, the holes 100 are arranged symmetrically towards the bottom portion of the cylindrical wall 92. The embodiment includes a group of eight holes 100 distributed circumferentially.

An annular flange 102 extends radially inwardly from the bottom edge of cylindrical wall 92 . an inwardly extending annular flange 10
2 has a bottom opening 104 forming the open end of the cup-shaped housing 90 to allow the wheel 62 and upper platen 36 to pass therethrough. A helium chamber seal ring 70 is attached to the annular flange 102 and extends radially inwardly therefrom to engage and provide a seal with the upper and lower platens 36, 40, respectively.

Additionally, FIGS. 2-4 each show a volume reduction disk 72 coaxially and slidably mounted for vertical circular motion on shaft 86 relative to cup-shaped housing 90 and upper platen 36. Disk 72 is disposed within housing 90 and is dimensioned to engage the top surface of annular flange 102 and rest when detector IO is in the rest position. The positioning of disk 72 limits the amount of probe gas escaping through bottom hole 104 with disk 72 dimensioned to ride closely to the inside surface of cylindrical wall 92 to reduce the volume of annular helium chamber 84. Decrease.

The detection device 10 is designed to be adapted to a range of wheel sizes consisting of a test wheel. 62 must be proportional to the volume around it.

In order to satisfy these conditions, an annular helium chamber 84
The amount of helium-air mixture in the disk 72 should be proportional to the volume inside the inner chamber 80 in the wheel 62 for wheels of various sizes. in combination with the outer chamber 34 to adjust the volume within the outer chamber 34 to achieve this requirement. As best shown in FIG. 4, the location of the outer chamber 34 and disk 72 is such that an annular helium chamber 84 has a size proportional to the wheel 62 under test, with the volume of the inner chamber 80 being controlled by the wheel cavity. form. The wall of the wheel 62 forms part of the boundary between the inner chamber 80 and the annular helium chamber.

A detection device 10 transfers the probe gas to an annular helium chamber 8.
Gas supplies, including those provided in FIG. 4, are generally mounted within a pressure fluid flow control system 200 (shown in FIG. 6). Flow control system 200
is connected to the annular helium chamber 8 via a gas connection line 110.
4 (see Figures 5 and 6),
The flow control system 200 includes a compressed helium gas source 202
and standard pressure regulator 204 and flow control device 206
, each of which communicates with a gas reading line 110 . Pressurized helium is inert and nonflammable;
A gas connection line 110 connects helium to the annular helium chamber 8.
a plurality of helium supply inlets 5 generally symmetrically distributed to 4;
It connects to 2.

A helium injector 112 is arranged in the gas connection line 110 , which is arranged between a compressed gas source 212 and a helium supply inlet 52 connected to a circular gas supply loop 130 . The helium injection valve 112 has an annular helium chamber 8
Allowing selective communication of helium to 4. In this embodiment, the helium injector 112 is actuated by an electrically controlled solenoid (shown in FIG. 7).

As shown in FIGS. 1-4, the invention further includes a vacuum generator to enable sampling of the atmosphere in the inner chamber 80 for probe gas.

Gas communication with the inner chamber 80 is provided by a vacuum pump 114 (Fig.
(with reference to FIG. 4). 10~1torr
Any readily available commercial vacuum pump that provides a pressure of r or 100 microns of mercury is also applicable.
As described in the text, vacuum pumps providing lower pressures are used with a corresponding reduction in cycle time, but the invention is practiced within the desired time constraints at pressures of 10 to 1 torr or 100 microns of mercury. That's enough. A vacuum suction line 32 connects the vacuum pump 114 to the inner chamber 80 via the main vacuum line 30. Bottom vacuum valve 26 is positioned between inner chamber 80 and vacuum pump 114 to selectively apply vacuum to inner chamber 80 and main vacuum line 30 . In this embodiment, a vacuum filter (not shown) is disposed between the vacuum pump 114 and the bottom vacuum valve 26 to prevent passage of oil gas into the inner chamber 80.
is actuated by an electric solenoid, while a vacuum release line 116 connects the main vacuum line 30 to the atmosphere. Vacuum release valve 28 selectively seals vacuum release line 116 from the atmosphere. In this embodiment, vacuum release valve 28 is electrically actuated.

As shown in FIGS. 1-4, the vacuum manifold 16
is in gas communication with main vacuum line 30 as well as with vacuum pump 114 and inner chamber 80 . The vacuum manifold 16 is
It includes a vacuum pipe bounded by an upper vacuum valve 18, a detection valve 22, a sample separation valve 20, and a vacuum line extending from instruments 12 and 14.

In embodiments, upper vacuum valve 18 is connected to vacuum manifold 16
and main vacuum line 30 with sample isolation valve 20 connected within gas vacuum line 54 . Vacuum manifold 16 helps generate and maintain the high vacuum necessary for proper operation of mass spectrometer 60.

Detection valve 22 is located between mass spectrometer 60 and sample separation valve 20, while vacuum gauges 12 and 14 are mounted to vacuum manifold 16 between upper vacuum valve 18 and detection valve 22. Each vacuum gauge 12.14, which may be any suitable commercially available instrument, includes a vacuum gauge switch 118 and 120, each of which is of the type that energizes an electrical circuit when the vacuum set level is achieved. . A sample connection line 122 connects the detection valve 22 to the inner chamber 80.
Gas is in communication with a mass spectrometer 60 which analyzes samples of the atmosphere from the air.

The mass spectrometer 60 is connected to the leak detection device 10 by the detection valve 22.
and is energized during the entire cycle of the leak detection device &10. Mass spectrometer 60 receives an atmospheric sample from inner chamber 80 via vacuum manifold 16 and sample connection line 122. Normally, connection line 122 is closed even when mass spectrometer 60 is energized. A small suction pump (not shown) disposed inside the mass spectrometer 60 is always energized. If detection valve 2
2 is closed, the mass spectrometer 60
When the detection valve 22 is opened, a small amount of sample air is drawn into the mass spectrometer 60 by vacuum. If the helium probe gas concentration is below a predetermined level, a small suction pump aspirates the essentially helium-free sample. Helium will be detected if the probe gas concentration exceeds a predetermined level.

Mass spectrometer 60 includes a detection switch (not shown) that includes a pair of leads that are opened or closed.

If the analyzer of mass spectrometer 60 indicates an insufficient helium concentration, the detection switch remains open, but if the helium concentration is above a predetermined level, the actuated detection switch is electrically A detection valve, which activates the system (see FIG. 7) to indicate a leaking wheel, also selectively communicates with the inner chamber 80t-amount spectrometer 60.

Although the various valves can be operated manually, FIG. 7 of this embodiment shows the operation of the solenoid operated valves and indicator lights described above. The lenoid is electrically actuated and sequentially operates multiple valves. As discussed below, the circuit described above provides an apparatus for monitoring process steps with the various indicators previously disclosed.

It should be appreciated that the disclosed electrical circuit is representative of only one of a variety of circuits capable of implementing a timed sequence of events.

Furthermore, the present invention includes the gas emitting device shown in FIGS.
Exhaust residual probe gas after removal from the probe. More particularly, in this embodiment, a pair of blower nozzles 46 are mounted on support plant form 44 adjacent lower platen 40 . These blow nozzles 46 are arranged upwardly with respect to the support platform 44 and effect a diversion with the air in communication with them. As will be discussed below, a blower 124 (see FIG. 7) is in gas communication with the pair of blow nozzles 46 by a blower connection line 126 to provide a flowing air mass or flow to remove residual air trapped within the inner chamber 80. The probe gas is swept to prevent erroneous analysis caused by mass spectrometer 60. Blower 124 is electrically operated and incorporated into the electrical circuit described with respect to FIG.

In another embodiment, the compressed air source is a pair of blower nozzles 4
6, and simultaneously opens and closes a compressed air source valve (see FIG. 6) equipped with an electrically actuated solenoid. a plurality of air cylinders (pneumatic jacks) 4 and pneumatically actuated jacking devices 89 (individually for the outer chamber 34);
Each pneumatically operated device, including air cylinder 50 (for upper platen 36) containing pneumatic expansion device 88, is operated from a local low pressure air supply (see FIG. 6).

FIG. 5 is a cross-sectional view of the bottom of the annular helium chamber 84, showing the gas connection lines 110 intersecting the helium injection valve 112, the gas contact lines 110 surrounding a portion of the housing 90 and distributed equidistantly around the circumference. Circular gas supply loop 1 with eight helium supply inlets 52
30 is the end. Each helium supply inflow section 52 is
T fitted into cylindrical wall 92 of cup-shaped housing 90
It is a form of finting. Viewed in cross-section through these telescoping fittings toward the bottom platen 40, the first interface line is a circular, annular flange 102 located at the bottom of the cylindrical wall 92.

The next interface line is the terminal edge of the helium chamber sealing ring 70,
The remainder of the annular helium chamber 84 is located at the wheel rim flange 8.
2 and a cross section through the side of the drum wheel 62. A marking between the annular ring 102 and the side edge of the wheel rim flange 82 allows helium probe gas to flow through the top view of the wheel 62, showing an opening 132 in the lower platen 40 for passing the vacuum suction line 32. shows.

t+ L 7'' 0- If gas leakage occurs from the boundary layer on the side of drum wheel 62, this indicates a defect in the structural integrity of wheel 62. 4) is the suction line 32.
A vacuum is drawn through the interior chamber 80 to evacuate the interior chamber 80 of the surrounding environment.

After the helium gas is injected into the annular helium chamber 84 from the eight helium supply inlets, the probe gas is forced into the sealed annular helium chamber 84 with the injection velocity applied to the helium. If the probe gas is present in the inner chamber 80, the existing environment will combine with the probe gas to form a mixture that is evacuated by the vacuum suction line 32 and It is delivered via main vacuum line 30 and vacuum manifold 16 to mass spectrometer 60 for analysis. The operation of the vacuum valve system will now be described with reference to FIGS. 6 and 7.

The operation of the vacuum valve system is controlled generally by an electrical circuit shown at 300 in FIG. Five vacuum valves are provided which operate according to the timing sequence described below. A bottom vacuum valve 26 is located in the main vacuum line 30 to switch the main vacuum supply on and off while simultaneously providing the required vacuum at the bottom of the detection device tIO to evacuate the inner chamber 80. Upper vacuum valve 18 is disposed within vacuum manifold 16 and is used to control the vacuum supply within vacuum manifold 16 and assists in drawing helium probe gas from helium supply inlet 52 into annular chamber 84 . Vacuum release valve 28 is located within main vacuum line 30 and vacuum release line 116 and is used to release vacuum from inner chamber 80 when testing on wheel 62 is complete. A sample isolation valve 20 is located within the vacuum manifold 16 and is used to introduce a fixed amount of a mixture of air and helium (or only air if there is no leak) from the inner chamber 80 . The mixture sample is temporarily held pending its injection into the mass spectrometer 60.
Finally, a detection valve 22 located at the inlet of the mass spectrometer 60 in the sample connection line receives the mixture sample from the sample separation valve 20 and delivers this sample to the mass spectrometer 60 in a timed sequence.

A pressurized fluid flow control system 200 is shown in FIG. 6 illustrating the components necessary to initiate delivery of probe gas into the annular helium chamber 84 and then deliver low pressure air to release residual probe gas. has been done. These components further include a helium measuring valve 208, a measuring cylinder valve 21
0, measurement cylinder 212 helium injection valve 112, outer chamber cleaning valve 214, upper platen solenoid valve 216, outer chamber solenoid valve 218, blower valve (platen cleaner) 1
24, blower connection line 126, blower nozzle 46,
6 includes a gas connection line 110, a circular gas supply loop 130, and a plurality of helium supply inlets 52, and in FIG. 26 and vacuum release valve 28 are shown. Finally, a low pressure air source 220 is shown and further includes an air manual valve 222 and an air cleaning, lubrication, and conditioning device 224 connected in series with an air line 226 .

One of the many novel aspects of the present invention is the preliminary determination of the exact amount of probe gas to be used for the particular wheel being tested. Preliminary measuring devices are integrated into the pressurized fluid flow control system 200 and include, among others, a helium measuring valve 208, a measuring cylinder valve 210, a measuring cylinder 2
12 and helium injection valve 112, once the preliminary measurement and injection of helium probe gas is completed;
Venting of residual probe gas is accomplished using an air line 226 in combination with the outer chamber cleaning valve 214 and blower valve 124 .

During the initial vacuum application stage, the vacuum A gauge 12 closes as the vacuum level increases. Under these conditions, helium measurement valve 20B is open (but helium injection valve 112 is closed).

The measuring cylinder 212 includes a pneumatically actuated and spring-returning piston, which piston is connected to the measuring cylinder 212.
Move inside and create a room within it. Measuring cylinder valve 21
2 opens, pressurized air from low pressure air source 220 is transferred through air line 226 and measurement cylinder valve 210. The low pressure passed through the measuring cylinder valve 210 enters the bottom of the measuring cylinder 212 and forces the piston to the top of the chamber transition therein. When the measuring cylinder valve 210 is closed, the piston is returned by the spring to the bottom of the measuring cylinder 212.

During the pre-measurement phase, the measuring cylinder valve 210 is closed and the helium pressure valve 208 is opened to allow helium to pass from the gas source 202 through the helium measuring valve 208 and to accumulate in the measuring cylinder 212 . The size of the wheel 62 being tested will affect the length of time required to develop the initial vacuum in the system. Once the initial volume reaches the working level, the vacuum B gauge 14 will B switch 120 is closed, thereby positioning the electric actuator within the vacuum valve to deliver helium probe gas to the annular helium chamber 84. However, helium measurement valve 20B remains open and directs the probe gas into the measurement cylinder. 212. Therefore, the amount of probe gas that accumulates in the measuring cylinder 212 is directly proportional to the time required to draw the required vacuum, and thus the volume of the inner chamber 80 of the wheel 62 under test. is proportional to.

When the vacuum B switch 120 closes, the helium measuring valve 20
8 is closed and the helium injection valve 112 is open, at which point the measurement cylinder valve 210 is opened to allow low pressure air from the air line 226 to flow through the measurement cylinder valve 210 and into the measurement cylinder 212. This low pressure air forces the piston in the measurement cylinder 212 to the top of the chamber, forcing helium probe gas out of the measurement cylinder 212 and through the helium injection valve 112, which is open. The probe gas passes through the gas connection line 110 to the circular gas supply loop 13
The probe gas flowing into the probe flows through a plurality of helium supply inlets 52 that deliver the probe gas to an annular helium chamber 84 .

When helium probe gas is forced out of the measurement cylinder 212, the measurement cylinder valve 210 closes the air line 22.
Air from cylinder 212 flows into cylinder 212.
12, thereby allowing the spring in the cylinder 212 to return the piston to its normal position. Thus, the amount of helium probe gas is measured by the time the helium probe gas flows during the pre-measurement phase. Ru.

The length of this time determines the amount of helium probe gas required to be stored within the chamber of measurement cylinder 212.

At the end of the test cycle, the helium injection valve 112 is closed and the outer chamber cleaning valve 214 is opened to open the gas connection line 1.
Air line 226 to 10 provides a passage for low pressure air. Low pressure air is passed through gas connection line 110 and gas supply loop 130 to displace residual probe gas. Low pressure air also flows through inlet 52 into annular helium chamber 84 to clean and vent helium probe gas from within the system for the next cycle. A vent hole 97 provided within the closed end 94 allows the released helium probe gas to vent through the top of the housing 90.

The blower valve 124 is activated during the period when the outer chamber cleaning valve 214 is open to allow release of helium within the annular helium chamber 84 . The low pressure air is therefore connected to the blower connection line 1
26 and blow nozzle 46 to clean the area around lower platen 40. Thus, during the pre-measurement phase, measuring the helium probe gas and delivering it into the annular helium chamber 84 and during the discharge phase, 90-100 hs i to clean the system.
This fluid piping system can be used to pass unmetered discharge air in the range of (Mkg/aJ).

Upper platen solenoid valve 216, outer chamber solenoid valve 218, and five vacuum operated valves (18, 20, 22,
26, 28) The valve pilots in each include standard solenoid four-way valves, each with a valve ball (not shown).
, which essentially provides a vacuum effect when the valve ball is in a first position and prevents a vacuum effect when the valve ball is in a second position.

This valve ball is pneumatically actuated by an air cylinder. However, the pneumatic cylinder is electrically actuated to provide or prevent pneumatic pressure from actuating the shaft for positioning the valve ball.

Regarding the operation of the sensing device 10, it is assumed that the device is in the reset position, in which the outer chamber 34 is connected to the upper platen 36 and associated seal ring 38, and the lower platen 40 and associated seal ring 38 are A distance is maintained from the seal ring 42. This spacing is sufficient to allow upper platen 36 to be above wheel rim flange 82 to allow removal of a tested wheel 62 and replacement of a new wheel to be tested between both platens. A volume reduction disk 72 is mounted on the top surface of the annular flange 102. The location of these components prevents residual probe gas from escaping from the bottom of the outer chamber 34 and further prevents contamination of the inner chamber 80 prior to applying a new wheel vacuum and beginning testing. Vent hole 97 provided in closed end 94 of cup-shaped housing 90
remains open for the exclusion of probe gas.

At this point, the next wheel 62 to be tested must be released by opening the vacuum release valve 28 and the flow of probe gas must be stopped by closing the helium injection valve 112, at the lower rim of the wheel. It rests coaxially on top of lower platen seal ring 42 which engages flange 82 . All vacuum valves are closed to the reset position during testing of each wheel 62 and then operated according to the sequence described below.

The electrical circuit 300 includes an upper vacuum valve 18, a lower vacuum valve 26,
further including solenoids and actuators for vacuum release valve 28, open sample separation valve 20 and detection valve 22;
Helium measurement valve 208, helium injection valve 112 measurement cylinder valve 210, air blower valve 124, outer chamber cleaning valve 214
and for the upper platen solenoid valve 216.

A detection switch disposed within mass spectrometer 60, including a solenoid and an actuator, is shown schematically in FIG. 7 and identified at 302. Furthermore, in FIG. 7, a lower vacuum indicator light 304, a detection indicator light 306, an upper vacuum indicator light 3
08, sample separation indicator light 310, helium injector indicator light 312, vacuum release indicator light 314 air blower indicator light 31
6, an outer room cleaner indicator light 318, a power "ON" switch 320, a power available indicator light 322, a reset switch 324, and a start switch 326 are shown.

Other indicator devices include a white light 328 to indicate that the wheel has passed the leak test, a red light 330 to indicate that the wheel has not passed the test, and a wheel that has been tested to indicate excessive leakage. A buzzer 332 is provided to indicate that the operation has been completed.

The remaining components on the electrical circuit diagram 300 of FIG.
shi-336, ri-shi-338
Lishi - 340, Lishi
-342, Relay 344 Relay 346, Relay 3
48 Relay 350 Relay 352, Relay 3
54, timer 356 timer 358, timer 360
Timer 362, timer 364, timer 366, timer 3
68, switch 370 switch 372, switch 374
and switch 376.

After the leak detection device 10 is energized or the leak test described above is completed, the upper platen 36 and outer chamber 34 are each in a raised (rest) position. Additionally, each vacuum operated valve is closed and the air blower valve 124 is closed. The next wheel test procedure is to first use the power rONJ.
It begins with closing switch 320, which connects input terminals 400, 401 to the electrical circuit and illuminates power available indicator light 322. The starting switch 326 has two poles,
A spring-loaded normally open pushbutton switch connects energized lead 401 from a powered "ON" switch to switch 374,376. Switch 374.3
76 is actuated by a potential impulse from start switch 326. The first impulse to lead 403 is:
A second operation of start switch 326 will pulse one of the switches ON, while the second of the two switches will pulse OFF via leads 403 and 422, reversing leads 403 and 422. switch 3
74 and 376 are reversed. Thereby, by actuating the start switch 326,
Electrical switches 374,376 are flipped. This causes lead 407 on switch 374 to be energized, thereby reducing the volume of measurement cylinder 212 to zero. The upper platen 36 connected to the lead 407 is lowered by gravity and forms an inner chamber 8o with the wheel 62 and the lower platen 40. At the same time, lower vacuum valve 2
6, upper vacuum valve 28 and sample separation valve 20 are each opened, while detection valve 32 and vacuum release valve 28, air blower valve 124 and vacuum release valve 28, respectively, remain closed.

Vacuum pump 114 begins to draw a vacuum within inner chamber 80, thereby increasing the overtime while timer 360
starts counting. Timer 360 is a 32 second timer that is used to limit the amount of time allowed for testing any particular wheel. Cup-shaped housing 90
supports a volume reduction disc 72 which acts as a dead weight bottom cap for the housing 90. Disk 72 is spaced several inches above upper platen 36 to isolate inner chamber 80 from helium contamination left in outer chamber 34 from the final test cycle.

The disk 72 is moved by a sufficient amount of vacuum to the upper platen 36.
unless the outer chamber 34 is sealed to the inner chamber 80.
remains in the raised position and supported by the

Vacuum A gauge 12 indicates that the initial level of vacuum is at manifold 1.
6, the vacuum switch 11B is activated. Vacuum A switch 12 is energized to activate relays 342 and 344.

Timer 366 energizes lead 410, which opens helium measuring valve 208, while relay 344's rising lead 424 causes measuring cylinder valve 210 to close, causing the spring to pull the piston downward, causing a larger Create a room for overtime. Lead 438 on relay 342 is actuated to cause the corresponding lead 4 on relay 352 to
20 is actuated to lower the cup-shaped housing 90 around the inner chamber 80 until it rests on the lower platen 4o. The volume reduction disk 72 of the housing 90 rests on the upper platen 36 and serves as a top cover for the annular helium chamber 84.

Inner chamber 80 is vacuum sealed before outer chamber 34 is lowered into lower platen 4o. However, if the upper and lower platen seals 38, 42 leak and the outer chamber 34 is lowered prematurely, residual probe gas will leak into the inner chamber 80.
Therefore, an acceptable level of vacuum must be established prior to lowering the outer chamber 34.
When the vacuum in manifold 16 that must reach gauge 12 is high enough to cause vacuum switch 118 to contact, lead 420 is energized and discharges from outer chamber 34.
0 Normally, the outer chamber solenoid 2
18 is energized by lead 420 which causes air cylinder 48 to maintain outer chamber 34 in the raised position.

However, when lead 420 is energized, outer lambda housing 34 is gradually gravity lowered onto lower platen 40. At this point, a preliminary measurement is taken as the helium probe gas enters the measurement cylinder 212.

When the vacuum reaches a preset level within manifold 16, vacuum B switch 14 is activated to close vacuum switch 120. Lower vacuum valve 26 is then closed by the action of relay 411 from relay 350. Measuring cylinder 212
The amount of helium probe gas in the chamber is proportional to the volume of the inner chamber 80 of the wheel 62 being tested. When vacuum B switch 14 is activated, lead 408 is connected to switch 372.
energizes the corresponding lead within to activate the lead 416 within the relay 346. Relay 346 energizes relay 448, which energizes the corresponding lead in timer 366. Lead 410 of timer 366 is actuated to close helium metering valve 208. Measuring cylinder 212
While the helium measuring valve 208 is open, its volume increases against the spring pressure. The helium probe gas passes through the helium injection valve 112 into the annular helium chamber 84.
was introduced gently into the measuring cylinder 212 in preparation for transmission to the measuring cylinder 212. After a delay of 1 to 5 seconds, relay 346 also energizes lead 435 to energize the corresponding lead in relay 344. Lead 424 of relay 344 then energizes helium injection valve coil 112, thereby Provides a passage for the probe gas from the measurement cylinder 212 to the gas connection line 110. Lead 424 on relay 344 energizes measurement cylinder valve 210 so that low pressure air from air line 226 causes the plunger of measurement cylinder 212 to rise against spring pressure, forcing helium probe gas through helium injection valve 112. and is directed through the gas connection line 110 to the circular gas supply loop 130 . Once the measuring cylinder valve 210 is closed, the piston of the measuring cylinder 212 is pulled by spring action.

After the vacuum B switch 14 is actuated, the vacuum is slowly drawn from the inner chamber 80 to the open sample isolation valve 20, the manifold 16, and the upper vacuum valve 18 as a sample of the mixture slowly circulates. continues to increase. The distribution of the air sample from the inner chamber 80 is 3
It lasts for several seconds as regulated by second timer 362 and causes the gas content of manifold 16 to be the same as the gas content of the air mixture in inner chamber 80 . After three seconds, timer 362 energizes lead 417 to close vacuum valve 18 while timer 362 lead 447 energizes relay 350 to cause lead 419 to close sample separation valve 20. At the same time, lead 415 of timer 358 energizes the corresponding lead to detect valve 22 which is regulated by 3 second timer 358.
open.

There are three conditions that can occur during testing of drum wheel 62. The first is that drum wheel 62 does not include any through holes and therefore does not allow probe gas to pass through. In this state, the drum wheel 62 is marked as a "good wheel." If the drum wheel 62 includes a small through hole, the probe gas will pass through the wheel 62 and the wheel will be labeled "E-defective wheel." In a worse case, there are large holes that allow an excessive amount of probe gas to pass through the drum wheel 62. In this case, this drum 62 is marked as a "critically bad wheel" and the test procedure is interrupted and terminated.

For each of the above three states, the leak detection device 10
are vacuum switch 118, vacuum switch 120 and 3
Different cycles are selected based on the combined management and reaction of the 2 second limit timer 360. The above description of pressurized flow control system 200 and electrical wiring diagram 300 is the same for all three conditions until detection valve 22 opens and passes a sample of atmospheric air from inner chamber 80 to mass spectrometer 60. be. The result of the analysis of the gas sample by mass spectrometer 60 determines whether detection switch 302 within mass spectrometer 60 closes energization lead 413 . The remainder of the description of the test procedure relates to the operation of the leak detection device 10 resulting from analysis of a gas sample.

If the helium concentration in the probe gas sample is extremely low, the helium concentration cannot be detected by the mass spectrometer 60;
Timer 358 will count to the end of its 3 second cycle, white light 32 indicating "good wheel"
8 will be illuminated and timer 360 will stop counting. Since the extremely low helium concentration will not be detected by the analyzer in mass spectrometer 60, detector switch 302 will not be actuated and circuit connected line 413 from it will not be detected by the analyzer in mass spectrometer 60. is not energized.

The operation of the electric circuit 300 is as follows. timer 35
At the end of the 8 3 second cycle, line 433 energizes the corresponding line in relay 342, which then energizes the corresponding line in relay 34.
2 lines 407 and 450 are energized.

Line 450 in relay 342 activates a corresponding line in timer 360, which causes timer 360 to activate line W prior to the 32 second time limit counted out.
energize. Line W of timer 360 energizes the white light to indicate that the tested wheel 62 does not leak probe gas; at the same time line 43 of relay 342
8 is deenergized and this simultaneously connects line 438 of relay 352.
Deenergizes the outer chamber solenoid valve 218 from the relay 352.
The line 420 to the coil is deenergized. This action actuates air cylinder 48 to raise cup-shaped housing 90 to its rest position.

3 after the cup-shaped housing 90 is driven to the rest position.
Within ~10 seconds, detection valve 22 is closed by deenergizing line 415 after timer 358 completes its 3 second cycle.

The remaining vacuum-operated valves are each in a closed position, including helium injection valve 112, which is connected to outer helium chamber 8.
4 and after delivery of helium probe gas to the outer chamber 34
is closed before being raised to the rest position. relay 336
stops counting and starts the basic 32 second cycle timer 3.
Reset 60. Line W is also connected from timer 360 to relay 336 which deenergizes line 451 in relay 336 as line W and relay 336 2 return to common line 400. This changes line 451 of relay 336 from the contact position to the open position. Line 415 also includes timer 356 and timer 3.
60, so line 45 of timer 356
1 is deenergized, line 444 of timer 356 also deenergizes the corresponding line to timer 360, terminating the cycle.

A discharge cycle is then triggered by lines 439 and 440 of 3 second timer 368. Line 422 of timer 368 energizes a corresponding line of switch 376 which powers line 425 of switch 376 and energizes the corresponding line of relay 352 . At this point, the cup-shaped housing 9o has reached its rest position and the lead 425
is energizing lead 434 of relay 352. Similarly, lead 434 of timer 364 is energized for 7 seconds.

Lead 434 of relay 352 also energizes lead 417 to open upper vacuum valve 18 for the ejection cycle. Lead 434 of relay 352 also actuates the corresponding lead of relay 348 energizing lead 419 to open sample separation valve 20.

Line 426 of relay 348 is also energized to open vacuum release valve 28 to release the vacuum in manifold 16, which in turn energizes air blow valve 124 and outer room cleaning valve 214.

Action of each of these valves by line 426 of relay 348 initiates a discharge cycle to clean the lower platen area, annular helium chamber 84 and manifold system 16.

The existing vacuum holds the wheel 62 tightened between the upper platen 36 and the lower platen 40 and receives a stamp indicating that the wheel is leak-free or a "good wheel." This stamping of the wheel is carried out manually or using a robot.

After stamping the wheel, reset switch 324 is actuated manually or robotically to raise upper platen 36 and place detection system 10 in the discharge condition. Reset switch 324 energizes leads 439 and 440 of timer 368 to sequentially reverse the order and close each vacuum operating valve and air blower valve 124, outer room cleaning valve 214, vacuum release valve 28 and through lead 407. Upper platen solenoid coil 216 is deenergized and air cylinder 50 is actuated to drive upper platen 36 upward. The leak detection device 10 is now in position to test the next wheel.

The mass spectrometer 60 detects the helium abundance within the manifold 16 by reading on a microvoltmeter installed therein, and this reading determines the relative proportion of helium in the gas sample distributed within the manifold 16. Additionally, the presence of helium in the gas sample analyzed by mass spectrometer 60 energizes detection switch 302 to power line 413 as described below. The detection switch 302 is an adjustment device such that the actuation point of this switch can be calibrated to be touched over a range of microvoltmeter readings. Thus, the boundary point between high helium concentrations indicating a bad wheel and low helium concentrations indicating a good wheel is adjusted to reflect the desired sensitivity.

The following description is based on the board 413 in the detector switch 302.
This relates to the operation of the electrical circuit 300 after it has been deenergized. However, it should be noted that the lead 413 can be used to operate robotic automated equipment to determine the leakage coefficient of each test wheel 62. After lead 413 is energized, the corresponding lead of switch 370 energizes lead R to energize red light 330 indicating that this wheel 62 has failed the leak test. Additionally, line 413 of mass spectrometer 60 also energizes a corresponding line in relay 354 to energize normally open leads 439 and 440. lead 43
9 and 440 energize the corresponding leads in 3 second timer 368 and short these leads together to start timer 3.
68 thereby initiating a discharge cycle and a reset of the leak detection device 10.

During the test procedure for a good wheel, receptacle 7) switch 324 connects leads 439 and 440 to timer 36.
8 must be activated manually or automatically. However, in the second condition during testing for a bad wheel, lead 413 of detector switch 302 shorts terminals 439 and 440 in relay 354, automatically activating timer 368;
Activate the emission cycle.

Once timer 368 is activated, lead 422 is energized to activate the corresponding leads in switches 372, 374, and 376. These three sui.

The switch is reset to return the leak detection device 10 to the first stage of the test procedure as follows. Switch 372 actuates line 416 to assist in opening the vacuum valve and actuating the discharge system. Switch 374 opens line 407 circuit and de-energizes the corresponding lead of relay 342. This causes lead 438 from relay 342 to energize the corresponding lead in relay 352, causing lead 438 to energize the corresponding lead in relay 352.
0 to operate the outer chamber solenoid 218 to the air cylinder 4.
8 to drive it upwards.

At the same time, deenergizing lead 407 deenergizes upper platen solenoid 216, causing air cylinder 50 to drive upper platen 36 upwardly to the rest position. The wheel 62 under test is connected to the upper platen 36 and the lower platen 4.
It is no longer tight between 0 and 0.

Thus, an attempt to stamp a "good wheel" on a wheel that has failed a leakage test will cause the wheel to flip.

Switch 376 energizes lead 425 and activates 7 second timer 364 to adjust the length of time for discharging probe gas detection device 1o. Line 434 of timer 364 energizes the corresponding lead in relay 348. Lead 426 of relay 348 is energized to actuate the electrical coils of vacuum release valve 28, air blow valve 124, and outer room cleaning valve 214 to perform a seven second discharge cycle.

Switches 374 and 376 are identical and each have a common wire 400 connected to the chassis return.
These switches have leads 403 and 422 respectively.
It should be noted that they are connected. It can also be seen that these two leads are connected in the reverse order within switches 374 and 376. switch 374
In , if electrical energy is supplied to lead 422, line 407 is disconnected from power lead 401. However, if electrical energy is delivered to lead 403, switch 374 changes position, lead 407 is energized, and the test cycle is resumed. lead 4
03 and 422 are in opposite order on switch 376 so that if electrical energy is supplied to lead 422, lead 425 will be energized by power lead 401.

However, if electrical energy is supplied to lead 403, lead 425 is disconnected from power lead 401.

It should be noted that the detection device 10 cycles through the entire procedure when the wheel passes the leak test and when the wheel fails the leak test. Thus, after vacuum B switch 14 is activated in the case of a good wheel test, timer 356 and timer 360 stop counting and the test cycle ends. Under conditions including testing for a bad wheel and after vacuum B switch 14 is activated, leads 439 and 440 of relay 354 are shorted to short timer 368.

As will be described later, mere operation of the vacuum B switch 14
It only indicates that the wheel is good and does not leak, or that the wheel leaks and fails the leak detection test. If the vacuum level within manifold 16 does not reach a sufficient level to activate vacuum B switch 14, a very poor leak within test wheel 62 is indicated. Under these conditions, the remainder of the test cycle lasts for less than 40 seconds.

When the test wheel 62 includes a large hole through which the probe gas passes through the structure of the wheel, the vacuum pump 11
4's ability reaches its limit. Under these conditions,
It increases very slowly over a much longer period of time than the 32 seconds allotted by limit timer 360. If the vacuum level necessary to operate mass spectrometer 60 is not achieved, vacuum switch 120 will not close and timer 360 will react to stop vacuum development. The absolute maximum length of one cycle of the detection device 10 is 55 seconds. Thus, if wheel 62 contains a hole large enough to prevent the required vacuum from developing within the stated time limits, timers 356 and 360 will interrupt and terminate the existing test cycle, causing the wheel to The delivery and removal conveyor system does not stop.

Timers 356 and 360 begin counting at the start of each test cycle. Timer 360 is a basic 32 second limit timer that will eliminate the wheel if the test is not completed within the allotted 32 seconds. Timer 356 overrides timer 360 to continue counting for an additional 8 seconds to provide the discharge function of this detection device 10.
It is a 2 second limit timer.

If vacuum switch 120 is not contacted within the 32 seconds allotted by timer 360, line 495 is energized for the additional 8 seconds required by the timer. Line 445 from timer 360 energizes a buzzer to provide an audible signal that the test wheel has been removed. During the 8 seconds that line 445 is energized, the vacuum application system is reset and the ejection cycle is completed. timer 3
After 56 completes the 42 second cycle, line 445 of timer 360 is deenergized and detector 10 is reset.

While resetting the detector, line 445 and lead 447
energizes and further actuates lead 419 to close sample separation valve 20. Furthermore, the lead 411 of the relay 350
is actuated to close the lower vacuum valve 26. Under these conditions, with the working vacuum reaching a magnitude that closes the vacuum switch 120, this sensing device 10 will complete a normal cycle within the allotted 32 seconds.
Lead 408 of switch 14 will energize the corresponding lead of switch 372, and detection device IO will continue the test cycle to determine whether the tested wheel passes or fails. However, lower vacuum valve 26 and sample separation valve 20 are closed before the end of the 40th count by timer 356 for the following reason.

The mass spectrometer 60 requires a high vacuum to function properly and the cycle is interrupted if the vacuum level does not reach the detection device 10 for the 0th order test cycle.
In order to properly reset the probe gas from this system, the vacuum within the manifold 16 must be released and the gas sample containing the high helium concentration must be released. The actuation valve must be opened in cycles to flow low pressure air through the outer room cleaning valve 214 and the air blower valve 124, if the detection valve 22 is opened for venting and at the same time the vacuum in the manifold 16 is removed. If the level is below the normal operating level, the mass spectrometer 60 will be damaged.

To avoid damage to the mass spectrometer 60, lower vacuum valve 2
6 and the sample separation valve 20 are connected to the relay 35 as described above.
It is closed by the operation of 0. In effect, this action separates the wheel 62 from the process of applying the vacuum. Separation of the wheel from manifold 16 is necessary to reset apparatus 10 because the large hole in wheel 62 allows probe gas to pass through and prevents vacuum development. vacuum pump 11
4 continues to draw vacuum in the manifold 16 from the upper vacuum valve 18. Sense valve 22 remains closed until the vacuum within manifold 16 reaches an operating level that closes vacuum switch 120. 3 second timer 358 leads 415
energizes the detection valve 22 to open and complete the analysis and release phase of the cycle. Once the required vacuum level is reached, the mass spectrometer 60 remains undamaged, and the sample atmosphere from the inner chamber 80 is introduced through the detection valve 22 and into the mass spectrometer 60 for analysis. Since the wheel being tested has a large hole, the sample has a high helium concentration.

Detector switch 302 is normally open, but energizes lead 413 in response to high helium concentrations in the gas sample. The corresponding lead activates switch 370 to energize lead R and illuminate red light 330 to indicate that the wheel has been removed. At this point, the value of the detection device 10 is assumed to be as if the test wheel had only a minor leak, but was rejected at the completion of the test cycle. Therefore, lead 41 of detector switch 302
Once 3 is energized, the electrical system 300 responds and performs a discharge and reset operation on its own in the same manner as previously described.

It is important to note that the electrical schematic shown in Figure 7 represents only one of several alternative electrical design wiring options that can be used to satisfy the vacuum working system test regime. It is. Therefore, the electrical wiring diagram 3 shown in FIG.
00 is merely an example and is not intended to limit the invention described herein.

From the above description, it can be seen that the leakage I* extraction device of the present invention is capable of testing each drum wheel for air leakage quickly and efficiently, and that the test is reliable and consistent with the principles of normal use of the wheel. It will be appreciated that this detection system is fully automated and is reset immediately after each test cycle is completed and stamps a "good wheel" test track indicia. This detection device can be equipped with robotic operating means that do not require a human operator.

The system of the present invention is used for fluid leakage testing of cast metal articles other than wheels, such as air conditioning pumps, water pumps, power steering pumps, compressor housings, engine cylinder blocks, cylinder heads, carburetor housings, and transmission housings. I know what I can do.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a leak detection device according to the invention, FIG. 2 is a partial sectional view of the leak detection device in a loaded position taken along vA2-2 in FIG. 1, and FIG. & in Figure 1
? 4 is a partial cross-sectional view of the leak detection device in a partially engaged position taken along line 4-4 of FIG.
FIG. 5 is a cross-sectional view of the annular chamber of the leak detection device in the locked position taken along line 5--5 of FIG. 1; FIG. is an electrical block diagram of the leak detection device shown in Fig. 2,
and FIG. 7 is a pressure gas flow diagram of the leak detection device of FIG. 1. Codes in the diagram: 10... Leak detection device, 12... Vacuum rAJ gauge, 14... Vacuum rBJ gauge, 16...
・Manifold, 18...Upper vacuum valve, 20...
- Sample separation valve, 22... Detection valve, 26... Lower vacuum valve, 28... Vacuum release valve, 30... Main vacuum line, 32... Vacuum suction line, 34...
・Outer chamber, 36...Upper platen, 38・
...Sealing ring, 40...Lower platen, 42
... sealing ring, 44 ... support plant form, 45 ... upper support structure, 46 ... blower nozzle, 4 ... air cylinder, 50 ... air cylinder, 52 ... helium Supply inflow section, 54... Gas vacuum line, 60... Mass spectrometer,
62...drum wheel, is shown. Engraving of drawings (no changes in content) l Meg A″C,, l Procedural amendment 4 (method) May 2nd, 1999

Claims (1)

[Claims] 1. A fluid leakage detection device in a cast article having a cavity, comprising: a sealing device for sealing the cavity of the cast article to form an inner chamber within the cavity; and an enclosure device having an open bottom for forming an annular chamber around the inner chamber; an evacuation device communicating with the inner chamber for generating a vacuum in the inner chamber; and an evacuation device for injecting a probe gas into the annular chamber. a supply device for entering said enclosure device; a measuring device in gas communication with said gas supply device for automatically pre-measuring a quantity of said probe gas delivered to said annular chamber; and said vacuum in said device. a valve arrangement disposed within the exhaust chamber for controlling and capturing a mixture sample from the inner chamber; and in gas communication with the inner chamber for analyzing the mixture sample and detecting the presence of the probe gas. an apparatus for detecting fluid leaks in a cast article, further comprising a detection apparatus in which the presence of the probe gas in the mixture sample indicates a leak through the cast article. 2. The casting of claim 1, wherein the measuring device includes a measuring cylinder for receiving the probe gas from a probe gas storage device and retaining the probe gas for the purpose of delivering the gas to the probe gas supply device. Device for detecting fluid leaks in articles. 3. The evacuation device includes a first vacuum switch actuated by a first vacuum level in the inner chamber, the actuated first vacuum switch activating a preliminary measurement of the probe gas in the flow control device. 2. The fluid leak detection device in a cast article according to 1. 4. further comprising an ejection device for entering the enclosure to inject a predetermined amount of air from a low pressure air source into the annular chamber to eliminate the probe gas and clean the annular chamber at the end of a leak detection test cycle. The apparatus for detecting fluid leakage in a cast article according to claim 1. 5. Claim 1 further comprising a helium injection valve for delivering the probe gas from the measurement device to the supply device.
A device for detecting fluid leaks in a cast article as described. 6. a lift device mechanically coupled to the enclosure device for providing vertical movement to the enclosure device during a leak detection phase; and a lift device vertically moves the enclosure device at the end of the leak detection phase; 2. The apparatus for detecting fluid leaks in a cast article as claimed in claim 1, further comprising a discharge device mounted below said enclosure for cleaning said probe gas from said apparatus after the probe gas has been removed. 7. further comprising a volume reduction disk having a central passage for receiving a central shaft secured to the central air cylinder;
a vertically movable upper platen of the sealing device, the volume reduction disk being mounted on the upper platen and annularly movable with the platen for adjusting the volume of the annular chamber in proportion to the volume of the drum wheel; 2. A fluid leak detection device in a cast article as claimed in claim 1, wherein the device is disposed between the moving volume reducing disk and a closed end of a vertically movable cup-shaped housing of an enclosure device. 8. The evacuation device includes a first vacuum switch actuated by a first vacuum level in the inner chamber, and the actuated first vacuum switch initiates a preliminary measurement of probe gas in the flow control device. , 4 and 5. 9. Claims 1 to 8, wherein the cast article is a drum wheel.
A device according to any one of the above. 10. A method for detecting fluid leakage in a cast article, the method comprising: sealing a cavity within the cast article to form an inner chamber within the cavity; and sealing the inner chamber to create a evacuated environment. evacuating and accommodating the sealed cast article in a housing to form an annular chamber surrounding the cast article, pre-measuring a portion of the probe gas proportional to the volume of the inner chamber; a plurality of vacuum line valves for supplying a pre-measured portion of the probe gas to the annular chamber for detecting leakage of the probe gas into the evacuated environment and for controlling the evacuated environment; sampling a portion of the evacuated environment within the inner chamber to perform a chemical analysis; analyzing the sampled portion of the evacuated environment to detect the probe gas; and A method for detecting fluid leaks in a cast article, including the step of indicating an analysis of the sampled portion, the presence of the probe gas in the evacuated environment indicating a leak in the cast article.