JP4389311B2 - Flow characteristic inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flow rate characteristic inspection apparatus. Specifically, for example, the present invention relates to an inspection apparatus for measuring the flow rate of fuel when a nozzle is opened in a fuel injection nozzle of an internal combustion engine to determine whether the flow rate characteristic is good or bad.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an apparatus for measuring an injection flow rate of a fuel injection nozzle used for an automobile is known. FIG. 2 is a schematic configuration diagram of a flow rate characteristic inspection apparatus according to a conventional embodiment.
[0003]
As an example of measurement by this apparatus, a nozzle (inspection object) 2 is set in a measurement apparatus (flow rate characteristic inspection apparatus) 1 and the inside of the nozzle 2 is connected through a connection joint 8 connected to a fuel inlet 15 of the nozzle 2. The fuel injection flow rate when the pressurized fuel is supplied to the nozzle and the nozzle 2 is opened is measured.
[0004]
[Problems to be solved by the invention]
However, in the conventional measuring apparatus, the external pressure applied to the nozzle (pressure contact load applied to the nozzle via the connection joint) is large, and the external pressure causes the entire nozzle to elastically deform and change the valve opening amount. Has the problem of different injection flow rates. Further, in the connection method using the O-ring shown in FIG. 3, the external pressure as described above is not applied, but the O-ring may be damaged due to misalignment or repetition during connection, and the O-ring becomes a defective part. In addition, there is a problem that the injection flow rate is erroneously determined due to the leakage amount due to the seal failure.
[0005]
The present invention has been made based on the above circumstances, and its purpose is to accurately measure the flow rate in actual use without deforming or scratching the object under test (for example, the fuel injection nozzle) during flow rate measurement. An object of the present invention is to provide a flow rate characteristic inspection device that can be determined as described above.
[0006]
To achieve the above object, in the first aspect of the present invention, the test fluid supply unit (4), the inspection object (2) and slidably retained movable body pressing direction (7), movable An O-ring (26) that seals between the body (7) and its holding part (22), and a spring (27) that acts to move the movable body (7) in the direction of the inspection object (2) And
When connecting the inspection object (2) to the movable body (7), a load obtained by compressing the spring (27) is applied to the movable body (7), so that the movable body (7) is attached to the inspection object (2). Pressure contact,
When inspecting the flow rate of the inspection object (2), in addition to the load of the spring (27), the movable body (7) is pressed against the inspection object (2) by the pressure of the inspection fluid,
The pressure receiving area in the sliding direction of the movable body (7) was made the same as the pressure receiving area in the actual use state of the inspection object (2).
[0007]
As a result, only a small load is applied when connecting the inspection fluid supply part (4) to the object to be inspected (2) , so that the entire nozzle is elastically deformed by the connection load, and the valve opening amount changes. There is no such thing as a different flow rate.
[0008]
In addition, since an elastic seal member such as an O-ring is not used for the connection part, the O-ring is scratched due to misalignment or repeated during connection, resulting in a defective part, and a leakage amount due to a seal failure is added to increase the flow rate. There is no longer a misjudgment.
[0009]
Further , the pressure receiving area in the sliding direction of the movable body (7) was made the same as the pressure receiving area in the actual use state of the inspection object (2) . Thereby, at the time of measurement, the seal is sealed by being brought into pressure contact with the pressure of the inspection fluid at a pressure corresponding to the actual use state, and the inspection is performed under conditions more suitable for the actual use state.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a schematic configuration diagram of a flow rate characteristic inspection apparatus according to an embodiment of the present invention.
[0012]
In the present embodiment, an example of measuring an injection flow rate of an inspection object (hereinafter referred to as a workpiece 2) using the flow rate characteristic inspection apparatus 1 shown in FIG. 1 will be described.
[0013]
The workpiece 2 to be measured is a fuel injection nozzle that supplies 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.
[0014]
The fuel injection nozzle includes a body 12 having an injection hole 11 at the tip, a needle 13 slidably housed inside the body 12, a solenoid 14 that drives the needle 13, and the like. Pressurized fuel is supplied from an inflow port 15 opening to the front.
[0015]
The operation of the fuel injection nozzle is such that the injection hole 11 communicates with the fuel passage 16 inside the fuel injection nozzle when the seat portion of the needle 13 is separated from the seat surface of the body 12, and is supplied to the fuel passage 16 from the inlet 15. High pressure fuel is injected from the injection hole 11 into the combustion chamber of the engine. When the seat portion of the needle 13 is in close contact with the seat surface of the body 12, the fuel injection from the injection hole 11 is stopped by blocking between the injection hole 11 and the fuel passage 16.
[0016]
Next, the configuration of the flow rate characteristic inspection apparatus 1 according to this embodiment will be described with reference to FIG.
[0017]
The flow rate characteristic inspection apparatus 1 includes a work holding unit 3 that holds a work 2, a test fluid supply unit 4 that supplies pressurized fuel to the work 2, a power supply unit 5 that supplies electricity for operating the work 2, and It comprises a measuring device 6 that measures the fuel injection amount (flow rate) from the work 2.
[0018]
Two workpiece holding units 3 are provided on the turntable (not shown) provided on the base of the flow rate characteristic inspection apparatus 1 so as to be axisymmetric.
[0019]
The inspection fluid supply unit 4 includes a main body block unit 21 connected to a pressurized fuel supply unit (not shown) that supplies pressurized fuel, and a movable body holding unit 22 provided below the main body block 21. It is fixed to the frame of the device on the work stop position on one side of the table.
[0020]
The main body block 21 includes a valve 23 that opens and closes pressurized fuel, and a valve drive unit 24 (hydraulic cylinder) that drives the valve 23.
[0021]
The movable body holding part 22 is connected to the lower part of the main body block 21 via an O-ring 25 for sealing, and is held between the movable body 7 and the holding part 22 so as to be slidable in the vertical direction. And an O-ring 26 for sealing, and a spring 27 for pressing the movable body 7 against the workpiece 2 when connected.
[0022]
The power feeding unit 5 is driven so as to come into contact with the connector unit 17 of the work 2 in a state of being connected to the fluid supply unit 4 and performs electrical connection.
[0023]
The measuring device 6 is specifically a flow meter, which is fixed to the main body block 21 and connected to a pressurized fuel supply means (not shown).
[0024]
Next, the operation in this embodiment will be described.
[0025]
First, the work 2 is set on the work holding unit 3 on a turntable (not shown). When the setting is completed, the turntable is rotated 180 degrees, and the work 2 is moved directly below the inspection fluid supply unit 4.
[0026]
Next, the work holding unit 3 is pushed up by an air cylinder (not shown), and the work 2 is connected to the inspection fluid supply unit 4. More specifically, the upper end surface of the fuel inlet 15 of the work 2 is brought into contact with the lower surface of the movable body 7 in the middle of pushing up, and the spring 27 is compressed so that the elastic force is applied as a contact pressure so as to maintain communication with the outside. To do.
[0027]
Next, the power feeding unit 5 is advanced and connected to the connector unit 17 of the work 2, and the valve driving unit 24 is operated to open the valve 23 to supply pressurized fuel as a test fluid to the work 2. At this time, since the movable body 7 is pressed against the workpiece 2 with the pressure of the pressurized fuel, the fuel does not leak to the outside.
[0028]
Next, the work 2 is energized by energizing from the power supply unit 5, the pressurized fuel is injected, the flow rate at that time is measured by the measuring device 6, and the quality of the flow rate characteristic is determined.
[0029]
Next, the power supply unit 5 is retracted to disconnect the electrical connection, and the valve drive unit 24 is operated to close the valve 23 and stop the supply of pressurized fuel. The work holding unit 3 is lowered to release the connection with the inspection fluid supply unit 4, and the turntable is rotated 180 degrees to complete one cycle.
[0030]
The flow rate characteristic inspection apparatus 1 of the present embodiment is provided with a movable body 7 that is slidably held in the pressure contact direction with the workpiece 2 in the inspection fluid supply section 4, and the workpiece 2 is inspected with the inspection fluid supply section 4 (movable body 7). Only the load which compressed the spring 27 is applied when connecting to, and at the time of inspection, the movable body 7 is brought into pressure contact with the workpiece 2 by the pressure of the inspection fluid.
[0031]
As a result, only a small load is applied when the inspection fluid supply unit 4 is connected to the workpiece 2, so that the entire workpiece 2 is elastically deformed by the connection load and the valve opening amount changes, and the injection flow rate is different from that during actual use. There is no such thing as becoming.
[0032]
In addition, since an elastic seal member such as an O-ring is not used in the connection part, the O-ring is scratched due to misalignment or repeated during connection, resulting in a defective part, and a leakage amount due to a seal failure is added, resulting in an injection flow rate. There is no longer a misjudgment.
[0033]
In addition, the pressure receiving area in the sliding direction of the movable body 7 is the same as the pressure receiving area in the actual use state of the workpiece 2. Thereby, at the time of inspection, the seal is sealed by being brought into pressure contact with the pressure of the inspection fluid according to the pressure in accordance with the actual use state, and the inspection is performed under a condition more suitable for the actual use state.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a flow rate characteristic inspection apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram of a conventional flow rate characteristic inspection apparatus.
FIG. 3 shows a connection method using a conventional O-ring. Moreover, it is a detailed view which shows the connection state at the time of actual use of a to-be-inspected object.
[Explanation of symbols]
1 Flow characteristics inspection device 2 Workpiece (inspection object)
3 Workpiece holding part 4 Inspection fluid supply part 5 Power supply part (flow path opening means)
6 Measuring instrument 7 Movable body 15 Fuel inlet

Claims (1)

A workpiece holding part (3) for holding the object to be inspected (2), and an inspection that abuts on the fluid inlet (15) side of the object to be inspected (2) and supplies the inspection fluid to the fluid inlet (15) A fluid supply section (4), a flow path opening means (5) for opening a flow path in the inspection object (2), and a measuring instrument for measuring the flow rate of the inspection fluid flowing in the inspection object (2) ( 6) with a flow rate characteristic inspection apparatus comprising:
The test fluid supply unit (4), wherein the inspection object (2) and slidably retained movable body pressing direction (7), said movable member (7) that the holding portion (22) An O-ring (26) that seals between and a spring (27) that acts to move the movable body (7) in the direction of the inspection object (2) ;
When the inspection object (2) is connected to the movable body (7), a load obtained by compressing the spring (27) is applied to the movable body (7), so that the movable body (7) is attached to the inspection object. Press contact with inspection object (2),
When inspecting the flow rate of the inspection object (2), the movable body (7) is pressed against the inspection object (2) by the pressure of the inspection fluid in addition to the load of the spring (27). And
The flow rate characteristic inspection device according to claim 1, wherein the pressure receiving area in the sliding direction of the movable body (7) is the same as the pressure receiving area in the actual use state of the inspection object (2).

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