JP2827442B2 - Workpiece hole closure detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to, for example, a water jacket or the like in a cylinder head or a cylinder block as an automobile part, or a work provided with a hole communicating with the inside in a part other than the automobile part. The present invention relates to a method for detecting hole blockage of a work, which measures the degree of communication between holes.

(Prior Art) There are various types of works having holes therein. The method of drilling holes also includes a method by casting, a method by machining, and the like. In any case, if the point communication degree of the hole is not as designed, the hole will not function properly. In other words, when a work is manufactured by casting, a burr-like object comes out inside the hole, so the opening area of the hole tends to be small, and when a hole is formed by machining, it is inevitable in a part where a tool is difficult to enter. The opening area of the hole becomes small. Therefore, processing is performed based on these conditions, but inspection must be performed one by one after completion.

If the work is a cylinder head or a cylinder block and the hole is a water jacket, the cooling performance of the engine will deteriorate unless the communication degree (closed state in the opposite term) of the water jacket is maintained at a predetermined value,
In some cases, seizure may occur. This can be said of the lubricating oil passage which plays an important role similarly to the cooling water. Therefore, the degree of communication between the water jacket and the lubricating oil passage must always be maintained at a predetermined value. The same is required for perforated members other than automobile parts.

Here, a cylinder head, which is a typical example of this type of work, will be described. A water jacket through which cooling water flows is provided on a cylinder head, which is a main component of the engine. This water jacket is generally formed at the time of cylinder head casting, and is finished to a predetermined shape by finishing after casting, but in the case of mass production of cylinder heads, each one is manufactured completely uniformly. It is difficult to perform the operation, and in some cases, in the open state or the closed state, there are cases where the shape or the degree of communication cannot be always satisfied.

When manufacturing in such a large quantity, if it is not possible to grasp the actual situation of the water jacket for all of them,
Since it is not possible to accurately grasp the positional relationship between the water jacket and the cylinder bore, the flow rate of the cooling water, in other words, the cooling capacity, etc., there is a need for engine performance such as stricter standards for the combustion chamber. A problem arises in which it is difficult to respond accordingly.

A patent invented to solve this problem has already been filed by the present applicant (Japanese Patent Laid-Open No. 3-102203).
No.). This is because air at a temperature different from that of the work is supplied to a hole provided in the work, so that the surface temperature after the temperature of the work becomes different, or air blown out from an opening of the work. The temperature of the workpiece is measured by a thermal image processing means, and the temperature of the measurement result is compared with a reference value to detect a closed state, thereby detecting a work blockage.

According to the method of the present invention, when the air supplied to the work is heated air, if the hole has a closed portion, the heated air stays in that portion, and the surface temperature rise is smaller than that of the unblocked work. Even if the blockage is not 100%, the resistance of the flow path is obtained. Therefore, the flow rate of the heated air changes according to the blocking state, and as a result, the surface temperature rises. By comparing this change with that of a normal product, it is possible to determine the closed state of the portion (in other words, the opening ratio). The same detection can be performed for cooling air as well as for heating air. Further, when such detection is performed, if there is a blockage in the hole, the blowout amount of the heated air (or cooling air) flowing through the portion changes, so that it is possible to estimate the blockage occurrence site.

(Problems to be Solved by the Invention) As described above, in the case of this application, extremely accurate and highly accurate measurement can be performed. However, when this method is actually performed, the above-mentioned advantages are obtained, but the difference image processing of the thermal images between the normal product and the test product, or the test product before and after heating (or cooling) and after heating is necessary, As a result, there are problems that a lot of time must be spent for the processing and that there is a problem in making the apparatus compact, and there is a problem associated with these in terms of cost.

An object of the present invention is to provide a method for detecting a blockage of a hole in a work, which solves such a problem that the above-mentioned technology is very excellent, but has improved reliability while being a simple method. With the goal.

(Means for Solving the Problems) According to the present invention, as a means for solving the above problems, air having a temperature different from the temperature of the work is supplied to the holes of the work having a hole communicating from one end to the other end. Then, the work temperature after the temperature change of the work having a different temperature,
At least one pair of temperature sensors attached before and after the location where the closed state of the communicating hole is detected is calculated, the temperature difference between the detected temperatures of the pair of temperature sensors is calculated, and each temperature difference is compared with a reference value. According to the present invention, there is provided a method for detecting a hole clogging of a work, wherein a state of blockage between the pair of temperature sensors is determined based on a result of the comparison.

(Operation) According to the work hole blocking detection method of the present invention having such a configuration, the output values of each pair of temperature sensors can be compared, so that the closing state of each part of the work can be quickly detected. Will be able to do that.

Next, an embodiment of the present invention will be described with reference to the drawings. First
The figure is a basic system diagram for realizing the method of the present invention, and a cylinder head portion as a work is a schematic representation of a cross section viewed from the side. In this figure, reference numeral 1 denotes an air supply source, which is connected to an air compressor and a reservoir tank (not shown) to supply air at a predetermined pressure.
An air supply valve 2 is connected to the air supply source 1 so that air supply to the pressure reducing valve 4 and the subsequent ones described below can be interrupted. The air supply valve 2 is an electromagnetic valve, and switches between a cutoff state and a communication state as shown by controlling the energization of the solenoid 3. The pressure reducing valve 4 has a pressure setting mechanism (not shown), and automatically sets the air received from the air supply valve 2 to the set pressure.

On the output side of the pressure reducing valve 4, a flow control valve 5 and a heating device 6 are connected in series. The heating device 6 heats air passing through the inside of the container 7 by a heater 8 provided inside the container 7. Although not shown, a temperature controller is provided inside the container 7 to change the heat generation amount or the heat generation time of the heater 8 according to the air temperature in the container 7 so that the temperature of the air passing through the container 7 is kept at a constant value. To keep it. An air supply nozzle 9 is connected to an outlet side of the heating device 6 so as to be in close contact with an inlet portion 11 of a cylinder head 10 which is a work. Many openings (not shown) provided in the cylinder head 10 are all closed. A contact member 12 is attached to the air supply nozzle 9, and when the air supply nozzle 9 is pressed against the cylinder head 10, the leakage is prevented by the contact member 12, and the water jacket 13 of the cylinder head 10 (position in the drawing Divided into waterways 13a, 13
b). 14 is a cooling water outlet, and 15 is a pressure gauge.

The illustrated cylinder head 10 is for a four-cylinder engine. Two temperature sensors 16a to 16h are respectively set in two water holes 15a to 15h for each two cylinders, which are communicating portions of a water channel with a cylinder block (not shown) of the cylinder head 10, for heating or The temperature of the portion of the cooled air is measured. The temperature sensors 16a to 16h provided in this manner are gripped by a sealing plate 17, which is a sealing means for sealing the water holes 15a to 15h, and when the sealing plate 17 is brought into close contact with the cylinder head 10, the temperature is reduced. The sensors 16a to 16h are adjusted so as to be set at positions suitable for detecting the temperatures of the respective water holes 15a to 15h.

FIG. 2 shows a plane view of a portion of the cylinder head 10 in FIG. Water holes 15a to 15h as shown in this figure
Are provided with water holes 15'a to 15'h, respectively. These water holes 15'a to 15'h also have water holes 15a.
A temperature sensor (not shown) is set in exactly the same way as in 15h. All of the temperature sensors 16a-16h (and not shown) are connected to the input side of an interface 18 shown in FIG. And this interface 18
The input side of the CPU 19 is connected to the output side of the CPU, and calculates the temperature difference between the pair of water holes, for example, the water hole 15a and the water hole 15'a, or the water hole 15b and the water hole 15'b. Then, the reference values are compared with each other to judge the quality, and a conclusion is made as to which part has an abnormality and how much the abnormality has been. Reference numerals 11b to 11d indicate junctions of cooling water. The display device 20 is connected to the output side of the CPU 19, and displays the output signal of the CPU 19.

Next, the principle of measurement in the method of the present invention will be described. The case where the work is heated will be described for convenience. The heated air 21 supplied from the air supply nozzle 9 is supplied to the cylinder head
From the inlet part 11 of 10, the water hole 15 a and the water hole 15 ′ a are almost equally divided, and the water hole 15 b and the water hole 15 ′ b are merged at the junction 11 b. If there is no abnormality in the water passages 13a and 13'a of the cylinder head 10, the cooling water flows smoothly and is discharged from the outlet 14 to the outside. In this case, the temperature sensors 16a to 16h
Outputs a normal temperature to the interface 18 corresponding to a case in which is not blocked.

Now, assuming that a closed portion 22a is formed in the middle of the water channel 13'a, the heated air 21 cannot flow from the junction 11b toward the water hole 15'd. The flow of the heated air 21 is blocked even when the closed state is not perfect. When the flow of the heated air 21 is blocked in this way, a large temperature difference occurs in the closed portion 22a. When the blockage 22b occurs in the water channel 13a, the flow 21b of the heated air from the junction 11c can hardly be expected, and as a result, the water hole 1b
The temperature difference between 5f and water hole 15'f becomes large.

In the case of the closed portion 22a, since there is the surrounding 21a of the heated air, the temperature difference becomes smaller than that in the case of the closed portion 22b. Therefore, by identifying these, the closed portion 22a and the closed portion 2
2b can be distinguished. When the blocking part 22c occurs,
Since the heated air 21 does not flow from the junction 11d to the water hole 15'g, the temperature difference between the water holes 15g and 15'g increases.
In this case, it can be distinguished from the above-described closed portions 22a and 22b by determining the number of the water hole having the increased temperature difference.

FIG. 3 shows an operation flow 30 of the measuring apparatus and a processing flow 40 of the CPU 19. This will be described. First, in step 31, the measuring device is activated, and in step 32, the air supply nozzle 9 is in close contact with the cylinder head 10. In step 33, the heater 8 of the heating device 6 is turned on, and in step 34, the solenoid 3 of the air supply valve 2 is excited to start air supply. The measurement of the heating time is started in step 35, and when a predetermined heating time has elapsed, a processing start signal is output to the CPU 19, and the processing is started in step 41.

The CPU 19 determines in step 42 that the water holes 15a to 15h and the water holes 15 '
The output signal temperature data T _{1 to} T ₈ and T ′ _{1 to} T ′ _{8 of} the temperature sensors 16 a to 16 h set to a to 15 h and the corresponding temperature sensors (not shown) , Which are denoted by the reference numerals for convenience) via the interface 18. Here, the temperature data of the temperature sensor 16a is T ₁ , and the temperature data of the temperature sensor 16b is T _2. Hereinafter, the temperature sensor 16h and the temperature data T ′ ₈ of the corresponding temperature sensor (not shown) will be described.
Up to the same.

In step 43, a difference ΔT _i = T _i −T ′ _i between the temperature data of the pair of water holes is calculated, and ΔT _i is stored. Steps
And "1" the i in 44, is compared with a reference value K _1, which is set in advance by experiment or the like in step 45. As a result, | ΔT _i
| <If K _1, water holes 15a, 15'a unit proceeds to step 46 it is determined to be normal. In step 46, if i = 8, then
Proceeding to step 47, add "1" to i and return to step 45. When i = 8 in step 46, it is determined that all of i = 1 to 8 are normal.
The CPU 19 outputs a "good" signal to the display device 20,
In step 51, the process ends.

[Delta] T _i | | in step 45 if the ≧ K _1, CPU 19 proceeds to step 49 it is determined that there is a closed unit, wherein storing the [Delta] T _i and i, together with the "defective signal" in Step 50 ΔT _i and i are output to the display device 20, and the process ends in step 51.
In this case, the worker changes the state of the closed part by i to the closed part 23a.
Or know a closed portion 23c type or a 23b-type, the sign of [Delta] T _i (+ or -), the presence position of the closure portion, know waterway 13a side or 13'a side. The degree of occlusion can be known from the absolute value of ΔT _i .

When the process ends in step 51, the CPU 19 outputs an end signal to the measuring device, and in step 36, the heater 8 of the heating device 6
Is turned off, the supply is stopped by deenergizing the solenoid 3 of the supply valve 2 in step 37, the supply nozzle 9 is retracted in step 38, and one cycle ends in step 39.

The above description has been made of the case where the heating air 21 is used as the air having a temperature different from the temperature of the work.However, the method of the present invention is not limited to the heating air. It can be realized by thinking.

FIG. 4 shows another example of the processing of the CPU 20. In this example, when the error of the reference value obtained experimentally, the variation of the temperature data due to the change of the external environment, and the like are taken into consideration, there is a possibility that the judgment is made by using only one reference value as in the example of FIG. Use when there is. The feature of this example is that a gray zone is set by having two reference values, and the level K1 that can always be judged as “good” even if the variation is considered
and _i, and sets the level K2i always even in consideration of variations can be determined that "defective" is obtained by the issue a re-check signal to an intermediate i.e. gray workpiece K1 _i and K2 _i.

Since the processing order is the same as that of FIG. 3 up to step 44, the description is omitted, but in step 45a, the absolute value of ΔT _i is always compared with the normal reference value K1 _i and | ΔT _i | <
If K1 _i, that is, normal, the process proceeds to step 46, and the same is repeated until i = 8. When i = 8, the process proceeds to step 48 to output a "good" signal. In step 45a, | ΔT
_i | ≧ K1 _i, that is, when it is not normal, the routine proceeds to step 49, where ΔTi and i are stored. Compared to a reference level K2 _i is always abnormal in step 45b, | ΔTi | <K2 _i ie not necessarily normal, but the process proceeds to step 50b when neither necessarily abnormal, and outputs a re-check signal. When the re-check signal is output, the worker inserts a wire or the like to check, or raises the hot air temperature for re-check,
A processing flow can be configured to re-compare with the reference value corresponding to the temperature.

When | ΔT _i | ≧ K2 _i in step 45b, it is always abnormal, so the process proceeds to step 50, where a “defective” signal is output. The processing after step 51 is the same as in the example of FIG.

In FIG. 5, the relationship between the temperature difference ΔT _i and the aperture ratio Ai experimentally determined in advance is set in the CPU 19, and the aperture ratio Ai is determined using the relationship, and compared with the reference aperture ratio AK. Here is an example in which the determination is made. According to this example, there is a feature that the closing state can be determined based on the opening ratio. FIG. 6 shows an example of a relationship diagram between the temperature difference and the aperture ratio. When the aperture ratio is 100%, the temperature difference is 0, and when the aperture ratio is 0%, the temperature difference becomes the maximum value in each part.

In FIG. 5, at step 45c, ΔT is calculated from the relationship of FIG.
Ai is obtained from _i , and the process proceeds to step 45d. In step 45d, the aperture ratio Ai is compared with the reference aperture ratio AK. If Ai ≧ AK, that is, if it is normal, the process proceeds to step 46. Similarly, the process is repeated until i = 8, and a non-defective signal is output until step 48. Step 45d
In Ai <When AK i.e. not normal, storing iA _i, and outputs together with the "defective" signal at step 50. Step 51
Subsequent steps are the same as those described above. As in the example of FIG. 4 in the case of this method, it sets the reference value AK ₁ and AK _2, it is also possible to gray zone process.

FIG. 7 shows an embodiment in which the thermal imaging device 23 is used for temperature measurement. In this case, the temperature change is detected by the infrared camera 23a due to the blockage, and the image processing means 23b performs electrical signal processing and inputs the processed signal to the interface 18. In this case, the sealing means 17 for sealing the water holes 15a to 15h
a to 17h and 17'a to 17'h are made of a material with relatively good thermal conductivity, and measure the temperature at the center of the pair of sealing means and judge the quality based on the temperature difference It is.

In all of the examples described above, the case where only one of the water passages 13a and 13'a is closed is described. However, when both of the water passages 13a and 13'a are closed, the detection becomes impossible because the temperature difference disappears. This problem can be solved by reading the supply air pressure data from the pressure gauge 15 at the same time as reading the temperature data, and determining whether the pressure value is equal to or lower than the set pressure. That is, in a state where both the water passages 13a and 13'a are closed, the air supply resistance becomes large, and the determination is made by using this.

(Effect of the Invention) As described above, the present invention supplies air having a temperature different from the temperature of the work to the hole of the work having the hole communicating from one end to the other end, thereby providing a different temperature. The temperature of the workpiece after the temperature change of the workpiece is detected by at least one pair of temperature sensors attached before and after the location where the communicating hole is detected, and a temperature difference between the detected temperatures of the pair of temperature sensors is calculated. Since each temperature difference is compared with a reference value, and a closed state between the pair of temperature sensors is determined based on a result of the comparison, a method for detecting a hole closing of a work is performed. Since the output values can be compared, it is possible to quickly and reliably detect the state of blockage at each part of the work. Further, the cost is lower than that of the above-mentioned prior art.

[Brief description of the drawings]

1 is a system diagram of an apparatus for realizing the method of the present invention, FIG. 2 is a plan view of a cylinder head portion which is a work in FIG. 1,
3 to 5 are flow charts showing the flow of processing, FIG. 6 is a graph showing the relationship between the aperture ratio and the temperature difference, and FIG. 7 is a system diagram of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Air supply source 2 ... Air supply valve 6 ... Heating device 9 ... Air supply nozzle 10 ... Cylinder head 13 ... Water jacket 13a, 13b ... Water channel 14 ... Outlets 15a to 15h, 15 ' a to 15'h ... water holes 16a to 16h ... temperature sensor 19 ... CPU 20 ... display device

Claims (1)

(57) [Claims] An air having a temperature different from the temperature of the work is supplied to the hole of the work having a hole communicating from one end to the other end. , Detecting at least a pair of temperature sensors attached before and after the portion where the closed state of the communicating hole is detected, calculating a temperature difference between the detected temperatures of the pair of temperature sensors, and comparing each temperature difference with a reference value. Then, a closed state between the pair of temperature sensors is determined based on the comparison result.