JPH06281548A - Inspecting apparatus for flow passage in molded item - Google Patents

Abstract

PURPOSE:To inspect every part of a flow passage at one time without overlooking a partial abnormality, by comparing the pressure difference between an exit where a pressure generating device is set and the other exit opened to the air with a reference value. CONSTITUTION:A vacuum pump 12 is set at an exit 2l of a cylinder block 2 having 12 exits. Connecting pipes 14g, 14h, 14i, 14j, 14k are connected at the exits 2g, 2h, 2i, 25, 2k. Moreover, pressure difference sensors P1, P2, P3, P4 are disposed between the connecting pipes 14g and 14h, l4h and 14i, 14i and 14j, 14j and 14k. Pressure differences in processes I, II, III, TV are accordingly detected. At the inspecting time, while the flow rate is held constant by a flow rate regulating valve 10, the vacuum pump 12 is actuated. As the air is sucked in through the exit 2f and discharged out from the exit 2l, the balanced condition is attained. The pressure differences P1-P4 in the processes 1-TI are detected in this state. A controller 16 obtains the sum of the pressure differences P1-P4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention inspects whether or not a flow channel is properly secured or formed in a molded article molded to secure a flow channel therein, such as an engine cylinder block. Related to the device. The term "molded product" as used herein refers to a product in which the wall material and the flow path are molded in the same process, such as a casting or a resin molded product.

[0002]

2. Description of the Related Art In order to inspect whether or not a flow path is properly formed in a cylinder block cast to secure a cooling water passage inside, a method disclosed in Japanese Utility Model Laid-Open No. 63-7344 is disclosed. Inspection devices have been proposed. In this device, a compressed air supply source is connected to one outlet of the flow path, and all the other outlets are hermetically sealed with a cap. Then, one of the caps is removed, a pressure gauge is attached, and compressed air is supplied from the compressed air supply source into the flow path. Depending on whether the pressure detected by the pressure gauge is close to the pressure that should occur when the flow path is properly formed, the outlet connected to the compressed air supply source and the pressure gauge are attached. It is inspected whether the flow path is properly formed between the outlets. The term "outlet" as used herein is a general term for a portion where a flow path is opened outside the molded product, and the inlet and the outlet are not distinguished.

[0003]

When inspecting the entire flow path by this apparatus, a compressed air supply source and a pressure gauge are attached to each outlet on the most upstream side and the most downstream side. If the pressure detected in this state is an appropriate value, the entire flow path should be properly formed. However, as a result of various experiments conducted by the present inventor, it was found that even if there is an abnormality in the middle portion of the flow path, the abnormality is often overlooked in the inspection device. This is probably because a slight abnormality in the middle portion may not affect the pressure as a whole. If an attempt is made to inspect for such an abnormality in the middle portion of the flow path, according to the conventional inspection device, the connection port for the compressed air and the mounting port for the pressure gauge must be replaced each time, and the inspection work is extremely troublesome. It will be. The present invention proposes an inspection device that can perform inspections for each part of a flow path at a time and does not overlook partial abnormalities.

[0004]

Therefore, in the present invention, an inspection device for a flow path in a molded article having the following constitution is created. That is, the inspection apparatus according to the present invention is an apparatus for inspecting whether or not the flow path is properly formed in a molded product that is molded so that a flow path having a plurality of outlets communicating with the outside is secured inside. A pressure generator attached to one outlet of the flow passage, and pressures in a plurality of strokes of the flow passage attached to a plurality of outlets other than the outlet to which the pressure generator is attached and at least another outlet. It is provided with a means for detecting a difference and a means for comparing the pressure difference detected in a state where the pressure generating device is operated with a reference value to determine suitability. The pressure generator here means a vacuum pump that generates a pressure lower than atmospheric pressure,
A compression pump or the like that generates a pressure higher than atmospheric pressure. The means for detecting the pressure difference may be a means for directly detecting the pressure difference, or a means for detecting the pressure and detecting the pressure difference from the difference between the detected values.

[0005]

According to the inspection device having this structure, a pressure difference is applied between one outlet to which the pressure generating device is attached and the other outlet which is not hermetically sealed and is open to the atmosphere. Then, in this state, pressure differences in a plurality of strokes of the flow path are detected. Then, since the pressure difference detected in each stroke is compared with the reference value, it is inspected in each stroke whether or not the flow path is properly formed. This inspection can be performed at one time, and it is not necessary to replace the pressure gauge etc. one by one. In addition, since the flow path is inspected for each stroke, it is possible to accurately inspect even a partial abnormality that is overlooked in the overall inspection.

[0006]

EXAMPLES Examples of the present invention will be described below. Figure 1 is the first
1 shows an embodiment and was developed for inspecting whether or not a flow passage 4 is properly formed in a cylinder block 2 of an engine. Although only the flow path 4 is schematically shown in the drawing, in reality, it is extremely complicated. This cylinder block 2 is for five cylinders, and five sets of the same flow path pattern are formed.
The flow path 4 communicates with the outside of the cylinder block 2 at a total of 12 points as indicated by 2a to 2l (ell). That is, it has 12 outlets.

One of these exits, in this case exit 2 l
A vacuum pump 12 is attached to (L) via a valve 8 and a flow rate adjusting valve 10. Connection pipe 14g at outlet 2g
However, the connecting pipe 14h is attached to the outlet 2h, the connecting pipe 14i is attached to the outlet 2i, the connecting pipe 14j is attached to the outlet 2j, and the connecting pipe 14k is attached to the outlet 2k. A pressure difference sensor P1 for detecting a pressure difference is attached between the connecting pipes 14g and 14h. A pressure difference sensor P2 for detecting a pressure difference is attached between the connecting pipes 14h and 14i. Connection tube 14i and 1
A pressure difference sensor P3 for detecting a pressure difference is attached between 4j. A pressure difference sensor P4 for detecting a pressure difference is attached between the connecting pipes 14j and 14k. Therefore, the pressure difference sensor P1 detects the pressure difference in the stroke I in the flow path 4, the pressure difference sensor P2 detects the pressure difference in the stroke II in the flow path 4, and the pressure difference sensor P3 detects the pressure difference in the flow path 4. Step III of
The pressure difference sensor P4 detects the pressure difference in stroke IV of the flow path 4. The remaining exits 2a-2f are
Except for one outlet 2f, they are hermetically sealed by caps 6a to 6e, respectively.

At the time of inspection, the vacuum pump 12 is operated with the flow rate kept constant by the flow rate adjusting valve 10. Then, the atmosphere is inhaled through the outlet 2f and flows out through the outlet 2l (ell), and in this state, the equilibrium state is reached. In this state, the pressure difference P1, P2 in the steps I to IV,
P3 and P4 are detected. Detected pressure difference P1, P
2, P3 and P4 are input to the controller 16.

The controller 16 is composed of a computer, and first obtains the total sum of the pressure differences P1, P2, P3 and P4. Then, the pressure difference is standardized by dividing the detected pressure difference by this total. Hereinafter, the normalized pressure differences will be referred to as Pa1, Pa2, Pa3, and Pa4. This normalized pressure difference becomes a relative pressure difference. Therefore, even if the pump capacity changes or the flow rate changes due to changes in temperature, the effect of the change is converted into a value that has been eliminated.

As described above, the cylinder head 2 has five flow path patterns. Therefore, if the flow path is properly formed, the pressure difference in each of the strokes I to IV should be substantially equal. Therefore, the standardized pressure difference Pai (i = 1 to 4) should be 0.25 (25%). An indicator 18 is connected to the controller 16, and the normalized pressure difference is displayed on the indicator 18 as illustrated in (a) to (e).

(A) shows the case where the flow path is properly formed, and the Pai (i = 1 to 4) is all about 25%. (b) shows that the pressure difference in stroke I is very large. That is, in the process I, the flow path is largely blocked and the flow path resistance is very large. This corresponds to the defect in the flow path in the process I.
In this case, even if there are no abnormalities in the strokes II to IV, the pressure difference deviates from 25% because the abnormally large pressure difference in the stroke I is used in normalizing the pressure difference. (c) shows that there is an abnormality in process II. In addition, (d) corresponds to the abnormality in process III. (e) shows that the pressure difference in stroke IV is relatively high, but it is within the range of variations that occur even if the flow path is properly formed. (a) ~ (e)
The upper limit and the lower limit shown in (1) indicate the range of variation that occurs even if the flow path is properly formed.

In the controller 16, whether or not all of the standardized pressure differences are below the upper limit and above the lower limit, that is, in the cases illustrated in (a) and (e), or
A program for discriminating the cases illustrated in (b) to (d) is incorporated. That is, the upper limit and the lower limit are used as reference values for discrimination. Then, according to this result, the display 18
OK or NG is displayed on the screen. According to this inspection device, a partial abnormality that would be overlooked in the overall inspection is not overlooked, and a normal thing is OK even in details, and NG is displayed if there is any abnormality. Become.

It is preferable to add a program to the controller 16 for further exchanging the standardized pressure differences Pa1, Pa2, Pa3, Pa4 based on the following equation. That is, PAMP1 = Pa1- (Pa2 + Pa3 + Pa4) PAMP2 = Pa2- (Pa3 + Pa4 + Pa1) PAMP3 = Pa3- (Pa4 + Pa1 + Pa2) PAMP4 = Pa4- (Pa1 + Pa2 + Pa3) When PAMPi (i = 1-4) is calculated,
The value in which the abnormal pressure difference is amplified will be calculated.
Therefore, if this PAMPi is compared with the upper limit and the lower limit, more accurate discrimination becomes possible.

Next, a second embodiment will be described with reference to FIG. The second embodiment differs from the first embodiment in the following points. The same flow path pattern is used for the test flow paths of the first embodiment.
Although the sets are repeatedly arranged, the inspection apparatus of this embodiment is designed so as to be able to inspect the flow path where such regularity is not recognized. b. In this embodiment, pressure gauges are installed at all of the outlets so that inspection of all the strokes (the stroke here means a flow path stroke between one outlet and another one outlet) is possible. It can be installed. An airtight cap can be attached to the outlet that does not require inspection, instead of installing a pressure gauge. FIG. 2 shows the atmosphere opening port 22e and the pump mounting port 22k.
It shows a state in which pressure gauges P1 to P9 are attached to all the other outlets except for. c. In the first embodiment, the pressure difference sensor for detecting the pressure difference is used, but in this embodiment, the pressure is detected, and then the pressure difference is calculated and obtained.

In the case of this embodiment, as in the case of the first embodiment, the vacuum pump 32 is operated to detect the pressure at each outlet while the atmosphere is sucked from the atmosphere opening port 22e. The vacuum pump 32 has a built-in intake air amount adjustment mechanism,
There is no need to use a flow control valve.

The object to be inspected shown in this embodiment has a very complicated internal flow path, for example, the outlet 22a is 22
The outlet 22b communicates with 22a, 22c, 22g, and 22i. A pressure difference is obtained for each stroke in accordance with this communication state. That is, the stroke pressure difference ΔP1 between the outlets 22a and 22b is obtained by the difference between P1 and P2, the stroke pressure difference ΔP2 between the outlets 22a and 22f is obtained by the difference between P1 and P5, and the stroke between the outlets 22a and 22j. The pressure difference ΔP3 of P is obtained by the difference between P1 and P9, and the pressure difference ΔP4 of the stroke between the outlets 22b and 22c is P
2 and P3, and the stroke pressure difference ΔP5 between the outlets 22b and 22g is determined by the difference between P2 and P6.
The stroke pressure difference ΔP6 between b and 22i is determined by the difference between P2 and P8, and the pressure differences for all strokes are similarly determined. It should be noted that this calculation is executed by the controller 36, and the controller 36 includes the detected values P1 to P1 of all pressure gauges.
P9 is input. The pressure difference Δ calculated in this way
Each of Pi (i = 1 to 6) is divided by the sum of the pressure differences and standardized. Normalized pressure difference ΔPai (i = 1
~ 6) correspond to the relative pressure difference.

In the case of the first embodiment, the suitability of the flow path is determined by utilizing the regularity that the pressure difference becomes substantially equal because the same flow path pattern is repeated. However, the apparatus according to the second embodiment is also capable of inspecting a flow path having no such regularity. Therefore, an appropriate number of cylinder blocks 22 in which the flow path is known to be properly formed are inspected in advance, and standardized pressure difference data is collected. As a result, as shown in the lower half of FIG. 2, the range of the allowable variation of the standardized pressure difference with respect to the proper product is determined.
The upper line ΔPai (MAX) in the figure shows the upper limit of the allowable variation, and the lower line ΔPai (MIN) shows the lower limit. In this case, since the flow path pattern has no regularity, the upper and lower limit values are different for each process.

The controller 36 is provided with a program for determining whether or not ΔPai ≦ ΔPai (MAX) and ΔPai ≧ ΔPai (MIN) for all i = 1 to 6.
If this is yes, it can be seen that the flow path is proper in all strokes, and if it is no, it can be seen that the flow path is abnormal in at least one stroke. The result of this determination is displayed on the display 38. In the case of this embodiment, since the reference values Pai (MAX) and Pai (MIN) for determining the suitability are determined from the inspection result of the proper product, the suitability for the irregularly arranged flow paths is also determined. Is determined.

Next, a third embodiment will be described with reference to FIG. In the third embodiment, the mounting of the inspection device on the molded product 42 is automated. When the molded product 42 is placed at a predetermined position, the cylinder 66 advances the seal block 46 and the seal block 46 causes the outlet 42a, 42b is hermetically sealed. Further, the cylinder 70 advances the block 68 to communicate the flow path 68a formed in the block 68 with the outlet 42c. Similarly, the cylinder 74 advances the block 72 to communicate the flow path 72a formed in the block 72 with the outlet 42h. Also, the cylinder 78
Moves the block 76 forward so that each of the flow paths 76d, 76e, 72f, 72g formed in the block 76 communicates with each of the outlets 42d, 42e, 42f, 42g. The differential pressure between the flow paths 76d and 76e is the differential pressure sensor P1.
The differential pressure between the flow paths 76e and 72f is detected by the differential pressure sensor P2, and the differential pressure between the flow paths 72f and 72g is detected by the differential pressure sensor P3.

The flow path 68a is connected to a vacuum pump 84 via a valve 80, and the flow path 72a is connected to a vacuum pump 84 via a valve 82. The valves 80 and 82 are switched so as to realize any of the following states. The first state is a state in which the flow path 68a is opened to the atmosphere and the flow path 72a is communicated with the pump 84. In this state, the air flows from the outlets 42c to 42h. The second state is a state in which the flow passage 72a is opened to the atmosphere and the flow passage 68a is communicated with the pump 84,
In this state, the atmosphere flows from the outlet 42h to the outlet 42c.

This inspection apparatus executes the inspection in both of the above states. Then, as shown in the lower column of FIG. 3, for example, 42c
Although the abnormal differential pressure is not detected in the state where the atmosphere flows in → 42h, the abnormal differential pressure may be detected in the state where the atmosphere flows in 42h → 42c. Alternatively, the reverse case is also possible. This is similar to the flow path indicated by 44b in FIG.
Although it greatly contributes to the flow from 2c to 42h, 4
Some of the flow of 2h → 42c does not contribute so much, or conversely, as shown in the flow path 44e, 42c → 4c
It is considered that there is a small contribution to the flow on the side of 2h and a large contribution to the flow from 42h to 42c. As described above, depending on the shape of the flow path, an abnormality may be overlooked in the inspection in one direction, but in this embodiment, the inspection is performed in both flows, so that an erroneous inspection is further prevented.
It should be noted that in this embodiment, when at least one of the differential pressures detected when flowing in both directions does not fall within the upper limit and lower limit regions, the inspection result is "defective".

In the above embodiments, the vacuum pump is used as the pressure generator. However, the pressure generator may be a compression pump that generates high pressure, and even in this case, the suitability of the flow path can be inspected for each stroke based on whether the differential pressure is normal or abnormal.

[0023]

According to the inspection apparatus of the present invention, the differential pressure is detected for each stroke in a state where a pressure difference is applied to the flow path, and this is discriminated as the reference value, so that normality / abnormality for each stroke is discriminated. Then, partial abnormalities that are overlooked in the overall inspection are accurately inspected. Further, the inspection process can be easily unmanned, and the inspection standard can be maintained at a constant level. Further, according to the present device, it is possible to identify the abnormal portion, and it becomes extremely easy to take countermeasures.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first embodiment.

FIG. 2 is a diagram illustrating a second embodiment.

FIG. 3 is a diagram illustrating a third embodiment.

[Explanation of symbols]

 Molded product: 2,22,42 Flow path: 4,24,44 Outlet: 2a to 2l, 22a to 22k, 42a to 42h Differential pressure sensor: P1, P2, P3 Controller: 16,36 Sealing cap: 6 For sealing Block: 46

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuya Sakai 1-1 Asahi-cho, Kariya city, Aichi Toyota Koki Co., Ltd. (72) Inventor Yoshiro Hayashi 1-cho, Toyota city, Aichi Toyota Motor Corporation Stock Company (72) Inventor Toyoji Ota 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Masaki Hito 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Hiroyuki Hatakeyama 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A device for inspecting whether or not a flow path is properly formed in a molded article molded to secure a flow path having a plurality of outlets communicating with the outside, A pressure generating device attached to one outlet of the flow passage, and an outlet to which the pressure generating device is attached and a plurality of outlets other than at least another outlet of the passage,
A means for detecting a pressure difference in a plurality of strokes of the flow path, and a means for comparing the pressure difference detected in a state in which the pressure generator is operated with a reference value to determine suitability. The inspection device for the flow path inside the molded product.