JPH0843061A - Apparatus for inspecting clogging of conduit - Google Patents

Abstract

PURPOSE:To prevent the generation of an incorrect inspection by detecting a pressure difference at a conduit in a work and a pressure difference at a reference diaphragm while the same flow rate is supplied to the conduit in the work and the reference diaphragm. CONSTITUTION:A differential pressure sensor 12 detects a difference of pressures at an opening WH1 and an opening WH2 of a work W, to detect a pressure difference at a conduit WH in the work. In the meantime, a differential pressure sensor 14 detects a pressure difference at a reference diaphragm 8a. Detecting values of both sensors 12 and 14 are input a controller 16. The controller 16 divides the pressure difference at the conduit WH in the work by the pressure difference at the reference diaphragm 8a, and compares the divided value with an upper limit is value and a lower limit value. If the divided value is between the upper and lower limit values, the work W : judged to be good. If the value is not between the limit values, tone work W is judged to be defective. Since influences by measuring conditions are cancelled, the result well conformed to a shape of the conduit WH in the work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an apparatus for inspecting a work, such as an intake manifold, in which a pipe should be formed in the work, whether or not the pipe in the work is properly formed. Regarding

[0002]

2. Description of the Related Art An example of a device for inspecting a conduit in a work is disclosed in Japanese Patent Laid-Open No. 3-105203. In this inspection device, while the high-pressure air is blown from one opening of the work internal conduit and discharged from the other opening, the difference between the pressure at one opening and the pressure at the other opening, that is, the work internal conduit Measure the pressure difference. If the internal work conduit is not formed as intended, for example, if the internal work conduit is clogged or the cross-sectional area is small, the pressure difference becomes significantly large. On the other hand, if the cross-sectional area of the conduit in the work is larger than intended, the pressure difference will be smaller. In this way, it can be inspected from the pressure difference whether or not the pipe line in the work is properly formed.

[0003]

However, this pressure difference is easily affected by factors other than the shape of the pipe line in the work. For example, when the temperature rises, the pressure difference tends to decrease. Alternatively, as humidity increases, the pressure difference tends to increase. For this reason, due to the influence of atmospheric temperature and humidity, the pressure difference becomes abnormal even if the work internal conduit is normal, or conversely, the pressure is increased even if the work internal conduit is not properly formed. The difference becomes normal.
The present invention realizes a technique for preventing the occurrence of such erroneous inspection.

[0004]

SUMMARY OF THE INVENTION The present invention is an apparatus for inspecting whether or not a pipeline is properly formed in a work, and a pipeline for inspection and one end of the pipeline for inspection are provided. A jig for communication that communicates with the pipeline in the work in a state of being cut off from the atmosphere, a high pressure or decompression generating means provided at the other end of the pipeline for inspection, and a middle of the pipeline for inspection. , A first differential pressure sensor provided on the communication jig and configured to detect a pressure difference in the work internal conduit, and a reference diaphragm provided on the inspection conduit. Ratio of the pressure difference in the work internal conduit by the second differential pressure sensor and the pressure difference in the reference throttle by the second differential pressure sensor. And a controller that determines whether or not the work internal duct is properly formed based on It is characterized by comprising. Here, the communication of the inspection pipeline and the workpiece internal pipeline in a state of being cut off from the atmosphere means that both pipelines communicate with each other and both pipelines are airtight to the atmosphere. Say.

[0005]

According to this inspecting apparatus, the gas to be inspected flows at the same flow rate in both the pipe line in the work and the reference throttle during the inspection. For this reason,
Even if the pressure difference in the work internal line fluctuates due to the temperature and humidity of the gas, the pressure difference in the reference throttle also follows the fluctuation, so that the pressure difference in the work internal pipe and the reference throttle eventually change. The ratio of the pressure difference is stable, and the correct inspection can be performed against the fluctuation of temperature and humidity.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below. In FIG. 2, the work W, in this case the intake manifold W, is provided with a conduit WH. This conduit W
H may be formed by casting, and it is necessary to inspect whether it is properly formed. The pipeline WH penetrates the work W and has at least two openings WH1 and WH2.

In the figure, reference numeral 20 is an inspection device, which has a pipe line 19 for inspection. One end of the inspection conduit 19 is communicated with the in-work conduit WH by the communication jig 2 while being blocked from the atmosphere. That is, the pipelines WH and 19 are communicated with each other, and both the pipelines WH and the pipelines 19 are hermetically sealed to the atmosphere at the connecting portion. That is, the communication jig 2
And the workpiece W are in contact with each other without any gap, and there is no leakage between them.

Reference numeral 4 in the drawing denotes a pipe airtightly attached to the communication jig 2, and forms a pipe line 19 by connecting with the communication jig 2, and a differential pressure sensor 12 is attached to the side wall thereof. Has been. The differential pressure sensor 12 has two ports 12a and 12b, one port 12a communicates with a conduit 19 inside the pipe 4, and the other port 12b communicates with the atmosphere. Reference numeral 6 in the figure denotes an on-off valve, which opens and closes the inspection pipeline 19. In addition, reference numeral 8 in the drawing denotes a tube in which a reference diaphragm 8a is formed. A second differential pressure sensor 14 is attached to the pipe 8. The differential pressure sensor 14 has two ports 14a and 14b. One port 14a communicates with one side of the reference diaphragm 8a and the other port 14b communicates with the other side of the reference diaphragm 8a. The pressure difference can be detected. 1 in the figure
Reference numeral 0 is a flow rate adjusting valve for adjusting the flow rate to a constant value, and P in the drawing is a pressure reducing means (vacuum pump in this case).

In the case of this apparatus, the communication jig 2 is used as the work W.
Atmosphere is sucked from the opening WH1 of the work W, flows through the internal work conduit WH from the opening WH1 to the side WH2, and vacuums the inspection conduit 19 from the side of the opening WH2. It flows to the pump P side. At this time, a pressure difference occurs in the openings WH1 and WH2 of the work W due to the pressure loss of the work internal pipe line WH. The differential pressure sensor 12 has the pressure (atmospheric pressure) at the opening WH1 and the opening WH2.
Is to detect the pressure difference at the
The pressure difference at is detected. On the other hand, the second differential pressure sensor 14 detects the pressure difference at the reference aperture 8a.

The detection values of both pressure sensors 12 and 14 are input to the controller 16. The controller 16 inputs the signals of the pressure sensors 12 and 14 and performs the processing described later,
The vacuum pump P, the on-off valve 6, and the flow rate adjusting valve 10 are controlled during the inspection so that a constant flow rate flows through the in-work workpiece pipeline WH and the inspection pipeline 19.

The flow rate is constant, and the pipe line WH in the work is
Even if the shape is constant, the pressure difference in the work internal conduit does not become constant due to atmospheric temperature and humidity. For example, when the temperature is high, the pressure difference becomes small, and when the humidity is high, the pressure difference tends to become large. Therefore, if the pressure difference itself is used as an index for inspection, the inspection result may be abnormal due to the influence of temperature and humidity even if the shape of the work internal conduit WH is normal, or the shape of the work internal conduit WH is abnormal. However, the inspection index may become normal.

However, in this apparatus, a flow rate equal to the flow rate in the pipe line WH in the work is made to flow through the reference throttle 8a,
The pressure difference at the reference throttle 8a is also obtained, and the ratio of the pressure difference at the internal conduit WH to the pressure difference at the reference throttle 8a is used as the inspection index. By obtaining this ratio, the effects of atmospheric temperature fluctuations and humidity fluctuations are canceled out, and the inspection results correspond well to the flow resistance of the pipeline inside the work.

The controller 16 is, as shown in FIG.
The pressure difference (PX) in the pipeline in the work is divided by the pressure difference (PM) in the reference throttle, and the divided value is compared with the upper limit value (UL) and the lower limit value (LL). Upper limit (UL) and lower limit (L
If it is between L), the work W is accepted, and if it is not, the work W is rejected. By doing so, the influence of the measurement conditions is canceled, and the inspection result that corresponds well to the shape of the conduit in the workpiece can be obtained.

In this embodiment, as the reference aperture 8a, a work W in which the work internal conduit WH is accurately formed, that is, a measuring master may be used. By doing so, the inspection result moves up and down around 1.0, and the inspection accuracy is improved. Further, in this embodiment, the pressure reducing means P may be replaced with a high pressure means. However, when the pressure reducing means is used, the differential pressure sensor 1 having better detection sensitivity.
2 and 14 can be used, and from the viewpoint of inspection accuracy, it is better to use the pressure reducing means. Further, in order to make the flow rate constant, it is possible to simplify the device configuration by using the pressure reducing means.
It is easier to maintain the airtightness of the communication jig 2 by further reducing the pressure and inspecting.

In this embodiment, the intake manifold shown in FIG. 1 can be inspected. This intake manifold W has one opening WH1 and six branch pipes W1 to W.
6 is provided so that each branch pipe can be inspected. Therefore, the jigs 21 and 2 for communication are connected to the branch pipes W1 to W6.
2, 23, 24, 25, 26 are attached, and the inlet WH1 and the outlet (communication jigs 21 to 26 and the branch pipes) for each branch pipe are respectively provided by the differential pressure sensors 121, 122, 123, 124, 125, 126. (W1 to W6 connection point)
The pressure difference between them can be detected.

However, this inspection device does not inspect the six branch pipes at a time, but inspects them one by one. For this purpose, on-off valves 61, 62, 63, 64, 65, 6 are provided at the downstream parts of the pipes 41, 42, 43, 44, 45, 46, respectively.
6 is provided, and the controller 16 uses the opening / closing valves 61, 62,
63, 64, 65, 66 are controlled. Controller 16
When the inspection of one branch pipe is completed, opens the on-off valve for the branch pipe adjacent to it and closes the on-off valve for the inspected branch pipe.

Reference numeral 70 in FIG. 1 denotes a collective member of inspection pipes, and 71 to 76 are inspection pipes branched corresponding to the respective branch pipes 41 to 46. In the case of this embodiment, each of the branch pipes W1 to W6 and the communication jigs 21 to 26 are communicated by one operation. Further, a pipe 8 having an aperture 8a formed therein is connected to the end of the collecting member 70, and a differential pressure sensor 14 is attached to the pipe 8. Tube 8
The pressure reducing means P is connected to the end of the. 6 like this
Even in the device for inspecting the branch pipe of the book, the number of the pipe 8, the differential pressure sensor 14 and the pressure reducing means P may be one. In the case of this embodiment, the inspection preparation process for the six branch pipes is executed at one time. Therefore, the preparation process is simplified. On the other hand, the actual inspection is performed one by one independently, and each branch pipe is accurately inspected one by one. In the case of the above-mentioned embodiment, in order to connect the inspection pipeline and the high-pressure or decompression means to one side of the workpiece, one communicating jig corresponding to one workpiece internal pipeline may be used. On the other hand, two communicating jigs may be used for one work internal conduit, the inspection conduit may be attached to one side of the work, and the high pressure or decompression means may be connected to the other side.

[0018]

According to the present invention, in the state where the same flow rate flows in the work internal pipe and the reference throttle, the pressure difference in the work internal pipe and the pressure difference in the reference throttle are detected, and the ratio of the two pressure differences is detected. Since it is used as an inspection index, it is possible to perform an inspection using an index in which changes in temperature and humidity are offset, and erroneous inspections are prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of an apparatus according to an embodiment.

FIG. 2 is a schematic diagram of an apparatus according to an embodiment.

FIG. 3 is a diagram showing an example of a measurement index.

[Explanation of Codes] 2 Communication jig 8a Reference diaphragm 12,14 Differential pressure sensor 19 Pipe for inspection P High pressure / decompression generating means W Work WH Work inner pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuya Sakai 1-1 Asahi-cho, Kariya city, Aichi Toyota Koki Co., Ltd. (72) Inventor Hironori Watanabe 1-cho, Toyota city, Aichi prefecture Toyota Incorporated (72) Inventor Yuuo Ogata 1 Toyota-cho, Toyota-shi, Aichi Toyota Automobile Co., Ltd.

Claims (1)

[Claims] 1. An apparatus for inspecting whether or not a pipeline is properly formed in a work, wherein an inspection pipeline and one end of the inspection pipeline are connected to the workpiece internal pipeline. A communication jig that communicates with the atmosphere in a state of being cut off, a high-pressure or reduced-pressure generating means provided at the other end of the inspection pipeline, and a reference diaphragm provided in the middle of the inspection pipeline, A first differential pressure sensor provided on the communication jig to detect a pressure difference in the work internal pipe; and a first differential pressure sensor provided to the inspection pipe to detect a pressure difference at the reference throttle. No. 2 differential pressure sensor, and the work internal duct based on the ratio of the pressure difference in the workpiece internal duct by the first differential pressure sensor and the pressure difference in the reference throttle by the second differential pressure sensor. And a controller that determines whether or not the Road-clogging inspection apparatus.