JP2001165802A - Leakage test apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leakage test apparatus 1 to reliably detect the leakage caused by, for example, defective welding without pressing a work 2 by the load applied during the leakage measurement. SOLUTION: A work support part 3c to support the work 2 is provided at the position closer to a fluid feed part 4 than a joined potion closest to the fluid feed part 4 so that the work 2 is held and secured by the work support part 3c and the fluid feed part 4. A work receiving part 3a slidable in the axial direction of the work 2 which is provided opposite to the fluid feed part 4 with reference to the work 2, and an elasticity maintaining member 3b to press the work receiving part 3c in the abutting direction of the work 2 on the fluid feed part 4 are provided. The work 2 is not pressed by the load applied during the leakage measurement, and a problem can be solved, in that a defective welding cannot be discovered even when abutting portions 20 of the parts are pressed against each other in the axial direction, and the leakage is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak measuring device. INDUSTRIAL APPLICABILITY The present invention is suitable for, for example, a leak inspection of a fuel injection nozzle of an internal combustion engine. In this case, the present invention is applied to a leak inspection device for detecting leakage of fluid from a body weld of the injection nozzle and determining the quality of the welded portion. It is possible.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus for inspecting a fuel injection nozzle used for an automobile, for example, for leakage.

FIG. 2 is a schematic configuration diagram of a conventional leak inspection device, and FIG. 3 is an explanatory diagram showing a schematic configuration of a fuel injection nozzle.

[0004] An example of inspection by this apparatus will be described. First, a nozzle (closed with a needle 13 in close contact with a sheet surface of a body 12) in a work holding section 3 of a leak inspection apparatus 1 is used. Work 2) is set. The fluid supply unit 4 is lowered by the air cylinder (main drive unit) 4a,
The nozzle 2 is brought into pressure contact with the end face on the fuel inlet 15 side. next,
A high-pressure air (inspection fluid) is supplied from the fluid supply unit 4 to the inside of the nozzle 2, and a change in the air pressure in the leak detection space 3 e due to air leaking through the welding portion 19 of the nozzle 2 after a predetermined time is calculated. It is detected and determined by a leak tester (measuring device) 5 communicating with the communication passage 3f.

[0005]

In order to seal high-pressure air supplied from the fluid supply unit 4 to the nozzle 2, a large pressing load is required. However, the conventional leak inspection device 1
Then, the fluid supply unit 4 and the work receiving unit 3 of the work holding unit 3
a is compressed by the pressure contact load, and the contact portion 20 in the axial direction of the parts is pressed against each other. For example, even if the welding portion 19 is defective, the leakage stops and the welding failure occurs. There was a problem that could not be found.

[0006] The present invention has been made based on the above circumstances, and an object of the present invention is to make it possible to reliably detect a leak due to, for example, poor welding without compressing the work with a press-contact load applied at the time of leak measurement. An object of the present invention is to provide an inspection device.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, the work (2) is formed by joining a plurality of members, and the fluid supply section (4).
A work supporting part (3c) for supporting the work (2) is provided at a position closer to the fluid supply part (4) than the joint part closest to the workpiece, and the work (2) is provided with the work support part (3c) and the fluid supply part ( 4) and held between them.

As a result, the pressing load applied by the fluid supply unit (4) to the work (2) is applied only to the contact portion between the work support unit (3c) and the work part below the work support unit (3c). Can be structured so as not to apply a load and to compress the work (2).

According to the second aspect of the present invention, a work receiving portion (2) slidable in the axial direction of the work (2) provided on the opposite side of the fluid supply portion (4) with respect to the work (2). 3a) and an elastic holding member (3b) for urging the work receiving portion (3a) in a direction in which the work (2) comes into contact with the fluid supply portion (4).

Accordingly, the work (2) is not compressed by the pressing load applied at the time of the leak measurement, and the abutting portion (20) in the axial direction of the parts comes into pressure contact with, for example, the welding portion (1).
Even if 9) is defective, it is possible to eliminate the problem that leakage stops and welding defects cannot be found.

Another effect of the invention according to claim 2 is that while the fluid supply part (4) is rising, the work receiving part (3a) is also raised by the spring, so that the work (2) is lifted. The attachment / detachment becomes easier compared to attachment / detachment to the bottom of the conventional deep hole.

According to the third aspect of the present invention, the leak detecting space (3e) and the measuring device (5) are communicated with each other by a driving force for bringing the fluid supply section (4) into contact with the work (2).

Thus, at the time of inspection, the fluid supply unit (4) is automatically connected to the measuring device (5) by bringing the fluid supply unit (4) into contact with the work (2), and is released when the fluid supply unit (4) is released. The structure (3) is separated from the measuring device (5). This is because, for example, the measurement device (5) may have a structure in which only the work holder (3) is replaced with a plurality of pieces and the work (2) is attached and detached and the inspection is performed in parallel to increase efficiency.
Need not be increased corresponding to the work holding part (3), and the cost of the leak inspection device can be reduced.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic overall configuration diagram of a leak inspection apparatus according to an embodiment of the present invention, and FIG. 3 is an explanatory diagram showing a schematic structure of a work and a welded portion of an inspection object (fuel injection nozzle). is there.

In the present embodiment, an example will be described in which a leak of the work 2 is inspected using the leak inspection apparatus 1 shown in FIG.

The work 2 to be measured is a fuel injection nozzle for supplying fuel to the combustion chamber of the engine. Since the configuration of the fuel injection nozzle (work 2) is very well known, only the main components will be briefly described here.

The fuel injection nozzle comprises a body 12 having an injection hole 11 at the tip, a needle 13 slidably housed inside the body 12, a solenoid 14 for driving the needle 13, and the like. Pressurized fuel is supplied from an inflow port 15 opening at the upper end of the fuel cell.

The operation of the fuel injection nozzle is such that when the seat portion of the needle 13 is separated from the seat surface of the body 12, the injection hole 11 communicates with the fuel passage 16 inside the fuel injection nozzle.
The high-pressure fuel supplied from the inflow port 15 to the fuel passage 16 is injected from the injection hole 11 into the combustion chamber of the engine. Further, when the seat portion of the needle 13 comes into close contact with the seat surface of the body 12, the space between the injection hole 11 and the fuel passage 16 is shut off, so that the fuel injection from the injection hole 11 is stopped.

This fuel injection nozzle has a body 1
2 and the pipe 17 and between the pipe 17 and the connector 18 are sealed and joined by laser welding, and the leakage inspection device of the present invention inspects the leakage from the welded portion 19 to determine the quality of the welding. .

Next, the configuration of the leak inspection apparatus 1 according to the present embodiment will be described with reference to FIG.

The leak inspection apparatus 1 includes a work holding section 3 for holding a work 2 and high-pressure air (inspection fluid) applied to the work 2.
And a measuring device 5 for detecting leakage from the work 2.

The work holding section 3 is held in a state of being floated by two axially symmetrical springs 6a provided on a turntable 6 provided on a base of the leak inspection apparatus 1. A work receiving portion 3a slidable up and down is provided inside, and is pushed up and held by a spring 3b.

A work supporting portion 3c for supporting the work 2 in the vicinity of a contact portion with the fluid supply portion 4 is provided on a side surface of the work holding portion 3, and an air cylinder (sub-drive portion) 3 is provided.
At d, the workpiece 2 is driven in a direction orthogonal to the axial direction of the workpiece 2 in accordance with the attachment and detachment of the workpiece 2.

Further, a communication passage 3f is provided on another side for communicating the leak detection space 3e formed when contacting the fluid supply unit 4 with the measuring device 5.

The fluid supply unit 4 and the measuring device 5 are installed at one of two positions where the work holding unit 3 stops on the turntable 6.

The fluid supply unit 4 is connected to pressurized air supply means (not shown) for supplying high-pressure air, and is driven up and down by an air cylinder (main drive unit) 4a. In addition, an upper die 4 slidable up and down around a contact portion with the work 2.
b is suspended by a spring 4c.

The measuring device 5 is specifically a leak tester, and a communication passage 5a that comes into contact with the work holding portion 3 and communicates with the communication passage 3f protrudes.

Next, the operation of this embodiment will be described.

First, a work (nozzle) 2 in a state where the injection hole 11 is closed (the needle 13 is brought into close contact with the sheet surface of the body 12) is set in the work holding portion 3 of the leak inspection device 1.

At this time, the work receiving portion 3a is pushed down by the flange portion of the body 12 so as to be brought into a pressure contact state by the load from the compressed spring 3b, and the forked work supporting portion 3c is formed.
Is inserted under the flange of the connector 18.

The work receiving portion 3a is sealed with an O-ring against the flange portion of the body 12 to form, for example, a section between the inflow port 15 having the weld 19 and the injection hole 11 side.
The leak from the weld 19 and the leak from the injection hole 11 are separated.

Since the work receiving portion 3a is slidable and is brought into contact with the spring 3b, the work 2 is not compressed between the fluid supply portion 4 and the work receiving portion 3a by the pressing load. The seal load required for the O-ring seal can be set to an appropriate load by the spring 3b.

When the setting is completed, the turntable 6 is rotated by 180 degrees, and the work holding section 3 is moved directly below the fluid supply section 4.

Next, the fluid supply unit 4 is lowered by the air cylinder (main drive unit) 4a, and the work 2 and the measuring device 5 are moved.
Connect with This is because first the upper mold part 4b is
, The spring 4c is compressed and brought into a press-contact state to form the leak detection space 3e.

Next, the fluid supply unit 4 and the work (nozzle) 2
The load applied from the contact portion is received by the work supporting portion 3c inserted immediately below the contact portion, and the work holding portion 3 is pushed down, and the spring 6a is compressed. You.

Then, the work holding unit 3 and the measuring device 5 come into contact with each other through the communication passage 3f and the communication passage 5a to be in communication with each other, and the load from the main driving unit 4a is applied to the fluid supply unit 4 and the work 2. And the contact portion between the work holding portion 3 and the measuring device 5 is applied and held as a pressure contact force, and becomes ready for inspection.

As a result, the pressing load applied to the work 2 by the fluid supply unit 4 is applied only to the contact portion between the work support unit 3c and the work 2 below the work support unit 3c without applying a load. Is not compressed.

At the time of inspection, the fluid supply unit 4 is pressed against the work 2 to be automatically connected to the measuring device 5, and when the fluid supply unit 4 is released, the work holding unit 3 and the measuring device 5 are separated. Structure. Accordingly, the measuring device 5 may be provided only on the stop position side where the inspection is performed, and the cost of the leak inspection device 1 can be reduced.

Next, high-pressure air (inspection fluid) is supplied from the fluid supply unit 4 to the inside of the nozzle 2, and after a predetermined time, the leak detection space 3 e due to the air leaking through the welding portion 19 of the nozzle 2. Is detected by a leak tester (measuring device) 5 communicating with the communication passages 3f and 5a to make a determination.

However, since the workpiece 2 is not compressed by the pressing load applied during the leak measurement, the axially abutting portions 20 of the components are pressed against each other and, for example, even if the welding portion 19 is defective, the leakage stops and the welding is stopped. The problem of not being able to find defects is eliminated.

Next, the supply of high-pressure air is stopped, the fluid supply unit 4 is raised, the connection between the work 2 and the measuring device 5 is cut off, and the turntable 6 is rotated by 180 degrees, so that the work support unit 3c
Is retracted, the work 2 is taken out, and one cycle is completed.

Since the work receiving portion 3a is pushed up by the spring 3b while the work 2 is separated from the fluid supply portion 4, the work 2 can be easily attached and detached as compared with the conventional attachment and detachment at the bottom of the deep hole.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of a leak inspection device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional leak inspection device.

FIG. 3 is an explanatory diagram showing a schematic structure of a work and a welded portion of an inspection target (fuel injection nozzle).

[Explanation of symbols]

 2 Work 3a Work receiving part 3b Spring (elasticity holding member) 3c Work support part 3e Leak detection space 4 Fluid supply part 5 Measuring device

Claims (3)

[Claims] 1. A fluid supply unit (4) for contacting a work (2) to supply a test fluid to the work (2), and a measuring device (4) for detecting leakage of fluid from the work (2). 5), wherein the work (2) is formed by joining a plurality of members, and the fluid supply unit (4) is more joined than the joint closest to the fluid supply unit (4). A work support portion (3c) for supporting the work (2) is provided at a position near the work (2), and the work (2) is sandwiched and held between the work support portion (3c) and the fluid supply portion (4). Leak inspection device characterized by being performed. 2. The work (2) provided on the opposite side of the fluid supply part (4) with respect to the work (2).
A work receiving part (3a) slidable in the axial direction of the fluid supply part (3), and an elastic holding member (3) for urging the work receiving part (3a) in a direction in which the work (2) comes into contact with the fluid supply part (4). 3
2. The leak inspection apparatus according to claim 1, wherein b) and b) are provided. 3. A leak detection space (3) by a driving force for bringing the fluid supply unit (4) into contact with the work (2).
3. Leak testing device according to claim 1, wherein e) and the measuring device (5) are in communication.