JP2679335B2 - Surface treatment method for aluminum cylinder block - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to the inner surface of each cylinder portion (portion forming individual cylinder bores) of a multi-cylinder cylinder block made of an aluminum alloy containing silicon (Si). In order to prevent the seizure of the piston to the cylinder, instead of providing a cylinder liner, aluminum that is suitable for use when performing a surface treatment to expose silicon crystals by corrosion of the aluminum base due to a chemical reaction on the inner surface of the cylinder The present invention relates to a surface treatment method for a cylinder block.

(Prior Art) An example of a conventional system for performing such surface treatment is shown in FIG.

This system comprises a pre-cleaning station 1, a surface treatment station 2 and a post-cleaning station 3, wherein the pre-cleaning and post-cleaning stations 1,3 are respectively provided with cleaning liquid tanks 4,6. Further, the surface treatment station 2 is provided with a treatment liquid tank 5, and these tanks 4 to 6 are provided with liquid temperature management systems 7 to 9 independent of each other.

In such a surface treatment system, the inner surface of the cylinder portion of the aluminum cylinder block, which is a workpiece machined in the pre-process 10 which is a machining process, is pre-cleaned with a cleaning liquid in the pre-cleaning station 1 and then processed in the surface treatment station 2. A step of performing a chemical corrosion treatment for exposing the silicon crystal with a liquid, and then performing a post-cleaning at the post-cleaning station 3 is performed. For the aluminum cylinder block after the surface treatment, the post-cleaning step 11 is an inspection step. Check the inner diameter of the cylinder.

In the above system, each liquid temperature management system 7
~ 9 are tanks 4 to 6 of the corresponding stations
The internal liquid temperature is maintained and managed regardless of the work temperature so that there is no problem in terms of cleaning and surface treatment efficiency.

(Problems to be Solved by the Invention) By the way, the surface treatment by a chemical reaction is greatly affected by the surface temperature of the object to be treated.

For example, FIG. 6 shows that a plurality of test pieces of the same quality as the aluminum cylinder block, which had been at room temperature, were immersed for 30 seconds in treatment liquids having different concentrations and liquid temperatures, and silicon crystals on the surface of each test piece were immersed. Shows the results of measuring the amount of protrusion (in this test, an aqueous NaOH solution was used as the treatment liquid, and α in the figure is 10
%, Β is 35%, γ is 60%), and as is clear from the figure, the amount of protrusion is large when the surface temperature of the test piece is changed by changing the liquid temperature at any concentration. Differences occur.

Therefore, at the time of the surface treatment, the surface temperature of the cylinder portion of the aluminum cylinder block needs to be made considerably higher than the outside air temperature in order to improve the treatment efficiency, so that the liquid temperature of the cleaning liquid in the pre-cleaning station 1 is also considerably high. Therefore, the cylinder portion is cooled in the atmosphere after the cleaning in the pre-cleaning station 1 and before the surface treatment with the treatment liquid in the surface treatment station 2.

In the case where the cylinder block has many cylinders, the heat capacities are usually different between the bore portions, and therefore, for example, in the case of four cylinders, the cylinder portions located at both ends are particularly likely to be cooled. different.

Therefore, even if the temperatures of the cylinders are equal at the end of the pre-cleaning, a temperature difference will occur between the cylinders when the surface treatment is started.

In addition, before entering the pre-cleaning station 1, the cylinder block has heat during the machining in the pre-process 10, and even if the cooling is performed between the pre-process and the pre-cleaning, the cylinder block is similar to the above. A temperature difference often occurs.

Therefore, it was extremely difficult to obtain a uniform amount of protrusion of silicon crystals between the cylinder parts during the surface treatment.

The present invention provides a surface treatment method that advantageously solves this problem.

(Means for Solving the Problems) A surface treatment method for an aluminum cylinder block according to the present invention comprises a pre-cleaning step of pre-cleaning the inner surface of each cylinder portion of a multi-cylinder aluminum cylinder block with a cleaning liquid, and In a surface treatment method of sequentially performing a chemical treatment step of chemically corroding the surface by filling with a treatment solution, a treatment solution after the pre-cleaning in the cleaning step and in the chemical treatment step Before filling, the temperature of each cylinder portion is measured, and based on the measured temperature of each cylinder portion, in the one according to claim 1, the liquid temperature of the treatment liquid in the chemical treatment step is calculated as follows. 3. Controlling for each cylinder part, and in claim 2, controlling the liquid temperature of the cleaning liquid in the pre-cleaning step for each of the cylinder parts and sequentially for the plurality of cylinder blocks. It is an feature.

(Operation) According to this method, based on the actual temperature difference obtained from the measurement result of the temperature of each cylinder portion after the pre-cleaning and before the filling of the processing liquid, the individual cylinder blocks are individually separated. In the case of control, control is performed to give a difference in the temperature of the processing liquid between the cylinder parts, and in the case of sequential control for multiple cylinder blocks, there is a difference in the temperature of the pre-cleaning liquid or the processing liquid between the cylinder parts. When controlling the liquid temperature of the cleaning liquid, the surface temperature between the cylinder parts before filling the processing liquid should be increased by increasing the liquid temperature of the cleaning liquid supplied to the cylinder part, which has a high cooling rate. The difference can be eliminated, and when controlling the liquid temperature of the processing liquid, while performing the surface treatment by increasing the liquid temperature of the processing liquid supplied to the cylinder part with a high cooling rate, Temperature between cylinders The degree difference can be appropriately reduced, and thus a uniform amount of silicon crystal protrusion can be obtained between the cylinder parts.

In the case of sequential control of a plurality of cylinder blocks, the temperature of both the cleaning liquid and the treatment liquid may be controlled, and if this is done, the takt time at each station of the surface treatment system can be shortened. Even if the temperature difference cannot be sufficiently eliminated with only one station, it is possible to obtain a uniform amount of protrusion of silicon crystals between the cylinder portions in the surface treatment station.

Further, according to this method, since the temperature difference between the cylinder parts is almost or completely eliminated during the surface treatment, a defect due to the temperature difference between the cylinder parts occurs in a post process after the post-cleaning. Even when the inspection is performed in the post-process after the post-cleaning, the measurement error due to the temperature difference hardly occurs or does not occur at all, and therefore the measurement work can be facilitated.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a configuration diagram illustrating a surface treatment system used in an embodiment of the surface treatment method for an aluminum cylinder block of the present invention. In the figure, the same parts as the conventional system are:
It is indicated by the same reference numeral.

That is, the surface treatment system here comprises a pre-cleaning station 1, a surface treatment station 12, and a post-cleaning station 13, wherein the pre-cleaning and post-cleaning stations 1 and 13 are each equipped with a cleaning liquid tank 4 , 15 are provided, the surface treatment station 12 is provided with a treatment liquid tank 14, and these tanks 4 to 6 are further provided.
Are provided with liquid temperature control systems 7, 16 and 17 which are independent of each other.

Further, here, the surface treatment station 12 is provided with a cylinder temperature measuring device 18.

FIG. 2 shows the structure of the surface treatment station 12, the treatment liquid tank 14, the liquid temperature management system 16 and the cylinder temperature measuring device 18 in more detail. In order to correspond to the aluminum cylinder block 25 of the cylinder, four processing liquid supply nozzles 12a, which are independent for each cylinder part, and those nozzles 1
It is equipped with four pumps (not shown) each connected to 2a via a conduit.

The cylinder temperature measuring device 18 provided in the surface treatment station 12 is equipped with two infrared radiation thermometers 18a. This infrared radiation thermometer was used because it has sufficient measurement accuracy, the measurement time is extremely short, and the temperature can be measured without extending the tact time of the surface treatment system. Other temperature measuring means may be used as long as there is no problem in terms of accuracy and measurement time.

On the other hand, the treatment liquid tank 14 also has four treatment liquid tanks 14a, each of which stores a treatment liquid 26 such as, for example, an aqueous NaOH solution, independently of each other in order to correspond to the in-line four-cylinder aluminum cylinder 25. It comprises four treatment liquid suction nozzles 14b respectively located in the treatment liquid tank 14a, these treatment liquid suction nozzles 14b, each of the four pumps of the surface treatment station 12 via a pipeline It is connected.

The surface treatment system here returns the liquid used in each station into each tank through a pipe line (not shown) after removing foreign substances by a filter (not shown),
Uses a liquid circulation system.

The liquid temperature conduit system 16 includes four heating devices 16a such as electric heaters provided for each processing liquid tank 14a in the processing liquid tank 14, and each processing liquid in the processing liquid tank 14 as well. Four liquid temperature sensors 16b such as thermocouples provided for each suction nozzle 14b, and the two infrared radiation thermometers 18a.
Infrared radiation thermometer 18a that controls the operation of
Output signal BT and the output signals LT of the four liquid temperature sensors 16b are input, and the operation of the four heating devices 16a is independently controlled based on those signals, for example, a control device 16c with a built-in microcomputer. I am.

Further, in FIG. 1, the post-cleaning station 13 is also
The surface treatment station 12 has an independent structure for each cylinder, and the cleaning liquid tank 15 and the liquid temperature management system 17 also have an independent structure for each cylinder similar to the processing liquid tank 14 and the liquid temperature management system 16. The liquid temperature control system 17 also receives the output signal BT of the two infrared radiation thermometers 18a.

In such a surface treatment system, pre-cleaning with a cleaning liquid is performed at the pre-cleaning station 1 on each of the four cylinder parts of the in-line four-cylinder aluminum cylinder block as the workpiece processed in the pre-process 10 which is a machining process. In the surface treatment station 12, a chemical corrosion treatment for exposing silicon crystals to the surface by the treatment liquid is performed, and then a post-cleaning is performed in the post-cleaning station 13, and the aluminum cylinder block after the surface treatment is processed. In the subsequent step 11 which is an inspection step, the inner diameter of each cylinder portion is inspected.

In the pre-cleaning at the pre-cleaning station 1, the liquid temperature control system 7 maintains the liquid temperature, which will be described later, higher than room temperature, and the cleaning liquid in one cleaning liquid tank 4 is supplied to all the cylinder parts. The cleaning liquid is supplied and the cleaning liquids having the same liquid temperature are used. As a result, as shown in FIG.
The aluminum cylinder block 25 that has been carried in has a temperature difference between the cylinder parts due to the cooling from the machining process to the pre-cleaning and the cooling from the pre-cleaning to the surface treatment.

In order to eliminate the influence of the temperature difference between the cylinder parts on the chemical treatment, at the surface treatment station 12, two control devices 16c are first activated by a start signal indicating the loading of the aluminum cylinder block 25 prior to the filling of the treatment liquid. Infrared radiation thermometer 1
The temperature of each cylinder portion of the cylinder block 25 is measured by 8a, and the output signal BT is input.

Here, each infrared radiation thermometer 18a is arranged so that two cylinder parts enter in the measurement screen, and the output signal BT of the infrared radiation thermometer 18a indicates the temperature distribution in the measurement screen. ing. For this reason, the control device 16c performs image processing in which a window is provided at a position corresponding to the cylinder section in the measurement screen, and particularly finds the temperature near the surface of each cylinder section.

Therefore, the number of infrared radiation thermometers 18a can be appropriately changed according to the type of aluminum cylinder block, the number of cylinders, the required temperature measurement accuracy, and the like.

Then, the control device 16c obtains a substantial surface temperature difference between the cylinder portions immediately before the surface treatment from the measured temperature in the vicinity of the surface of each cylinder portion, and based on the temperature difference, each treatment liquid tank 14a as follows. The heating device 16a corresponding to is activated.

That is, when a treatment liquid having a liquid temperature higher than the reference temperature is filled in the cylinder portion of the multi-cylinder cylinder block having a surface temperature lower than a predetermined reference temperature, the surface temperature of the cylinder portion becomes the reference immediately after the filling. After exceeding the temperature, the temperature of the processing liquid once rises close to the original temperature of the processing liquid, and then the temperature of the processing liquid in the cylinder decreases along with the temperature of the processing liquid due to heat conduction to the peripheral portion of the cylinder. On the other hand, even if the other surface of the cylinder whose initial surface temperature is equal to the reference temperature is filled with the treatment liquid having the liquid temperature equal to the reference temperature, the heat transfer to the peripheral portion of the cylinder hardly occurs, so Neither the surface temperature nor the temperature of the treatment liquid changes.

Therefore, for the cylinder portion whose initial surface temperature is lower than the reference temperature, the surface temperature of the cylinder portion is slightly lower than the reference temperature at the end of the treatment based on the relationship between the treatment liquid temperature and the silicon crystal protrusion amount described above. If the temperature of the initial processing liquid is set higher than the reference temperature so that it becomes lower, the surface temperature of the cylinder part changes from the start to the end of the process, so the chemical reaction rate changes, but the process ends. The amount of protrusion of silicon crystals on the surface of the cylinder portion at that time is substantially equal to the amount of protrusion of silicon crystals at the end of processing in the cylinder portion whose initial surface temperature is equal to the reference temperature.

FIG. 3 shows the result of measuring the distribution state of the cylinder surface temperature after performing pre-cleaning on an actual in-line four-cylinder aluminum cylinder block by the conventional surface treatment system in the same manner as this embodiment. As indicated by the solid line A,
The outer first and fourth cylinders are lower than the inner second and third cylinders. Among the cylinder parts having such a temperature difference, the liquid temperature of the processing liquid supplied to the cylinder parts of the second and third cylinders and the liquid temperature of the processing liquid supplied to the cylinder parts of the first and fourth cylinders are: As shown by the chain line B in the figure, a temperature difference that raises the liquid temperature of the latter is given, and as a result of performing the surface treatment by filling the treatment liquids in the respective cylinder portions, the actual amount of protrusion of silicon crystals between the cylinder portions is the same. was gotten.

Based on this theory, in this surface treatment system, the reference temperature is set to a liquid temperature that makes the efficiency of the surface treatment good, and the inside of the aluminum cylinder block 25 carried into the surface treatment station 12 after finishing the pre-cleaning, The liquid temperature control system 7 of the pre-cleaning station 1 adjusts the liquid temperature of the cleaning liquid so that the surface temperature of the cylinder parts of the second and third cylinders becomes the reference temperature as shown by the solid line in FIG. Therefore, the control device 16c corresponding to the surface treatment station 12 sets the temperature of the treatment liquid supplied to each of the second and third cylinders to the reference temperature as shown by a chain line B in FIG. 3, and In order to appropriately raise the liquid temperature of the processing liquid supplied to each of the first and fourth cylinders above the reference temperature based on the measured temperature difference,
The heating device 16a corresponding to each treatment liquid tank 14a is operated to adjust the treatment liquid temperature in each treatment liquid tank 14a.

The relationship between the temperature difference between the cylinders before the treatment starts and the temperature of the treatment liquid supplied to each cylinder that can equalize the protrusion amounts of the silicon crystals at the end of the treatment depends on the type of cylinder block and Since the heat capacity distribution will change if the type is different, it must be measured and obtained in advance for each type and type of cylinder block.This system also measures the four cylinders in advance and performs the above control. It is stored in the device 16c.

As described above, according to this surface treatment system, it is possible to obtain a uniform amount of protrusion of silicon crystals between the cylinder parts and also to substantially eliminate the temperature difference between the cylinder parts at the end of the surface treatment. You can

Then, in this surface treatment system, further, at the surface treatment station 12, after the completion of the surface treatment, the control device 16c causes the two infrared radiation thermometers 18a to measure the temperature of each cylinder portion of the cylinder block 25 again, Its output signal BT
Is input by the control device of the liquid temperature management system 17 corresponding to the post-cleaning station 13 having the same configuration as the control device 16c.

Then, the liquid temperature management system 17 considers the cooling from the end of the surface treatment to the post-cleaning and the cooling from the post-cleaning to the post-process, in the same manner as the liquid temperature management system 16 in the surface treatment station 12. , So that the temperature of the cleaning liquid supplied to the cylinder parts of the first and fourth cylinders, which temperature tends to decrease, is higher than the liquid temperature of the cleaning liquid supplied to the cylinder parts of the second and third cylinders. The temperature of the cleaning liquid in the cleaning liquid tank is adjusted.

Therefore, according to this surface treatment system, it is possible to eliminate the temperature difference between the cylinder parts even when performing the inspection in the post-process 11, and it is possible to avoid the occurrence of a measurement error between the cylinder parts due to the temperature difference, which in turn The measurement work can be made extremely easy.

In addition, in order to perform necessary liquid temperature adjustment within one tact time per work in each station in the surface treatment system, the liquid amount in the treatment liquid tank 14 and the cleaning liquid tank 15 and the heating capacity of the heating device are set. Since it is not practically effective to set it, here, the surface treatment system is started up with a certain amount of liquid in the treatment liquid tank 14 and the cleaning liquid tank 15 and the same heating capacity for heating and placing as before. Sometimes, based on the temperature difference between the cylinders measured in advance, the liquid temperature corresponding to each cylinder in the treatment liquid tank 14 and the cleaning liquid tank 15 is adjusted, and after the start of operation of the surface treatment system, the temperature is adjusted to that value. Based on the temperature difference measured in the flowing cylinder block, control is performed to stabilize the conditions over a certain period of time.

FIG. 4 is a configuration diagram illustrating a surface treatment system used in another embodiment of the present invention. In the figure, the same parts as those of the conventional example or the previous embodiment are designated by the same reference numerals.

That is, in this surface treatment system, the pre-cleaning station 19 and the post-cleaning station 20 each have an independent cleaning liquid supply / discharge path for each cylinder, similar to the surface processing station 12 in the previous embodiment. The cleaning solution tanks 21 and 22 corresponding to 20 and 20 are provided with independent cleaning solution tanks for each cylinder, similar to the processing solution tank 14 used in the surface processing station 12 in the previous embodiment. Liquid temperature control systems 23 and 24 respectively corresponding to the liquid temperature control systems 23 and 24 respectively adjust the liquid temperature of the cleaning liquid in each cleaning liquid tank, similar to the liquid temperature management system 16 used in the surface treatment station 12 in the previous embodiment. It is equipped with a heating device and a control device.

Further, here, the same surface treatment station 2 as the conventional example is provided with the same cylinder portion temperature measuring device 18 as that used in the surface treating station 12 in the previous embodiment, and the output of this cylinder portion temperature measuring device 18 is provided. Liquid temperature control system 23,24 corresponding to both cleaning stations 19,20 with signal BT
The control device having the same configuration as that of the control device 16c in the above embodiment inputs.

In this surface treatment system, as in the previous embodiment,
The surface of each cylinder of the aluminum cylinder block as a workpiece machined in the pre-process 10 which is a machining process is subjected to a pre-cleaning process, a chemical treatment for exposing silicon crystals, and a post-cleaning process. The subsequent aluminum cylinder block will be inspected in the subsequent step 11.

However, here, in the surface treatment station 2, the cylinder temperature measuring device 18 measures the temperature of each cylinder before filling the inside of each cylinder of the aluminum cylinder block with the treatment liquid, and outputs the measurement result output signal. Based on BT
Liquid temperature control system 23 corresponding to pre-cleaning station 19
In consideration of the cooling from the machining process to the pre-cleaning and the cooling from the pre-cleaning to the surface treatment, the above control device of the same as the liquid temperature management system 16 in the surface treatment station 12 of the previous embodiment. Pre-cleaning station 19
The temperature of the cleaning liquid to be supplied to each cylinder section in
The liquid temperature of the cleaning liquid in each cleaning liquid tank of the cleaning liquid tank 21 is adjusted so as to be higher than the cylinder portion of the second cylinder.

Therefore, according to this surface treatment system, the temperature difference between the cylinder portions before the start of the surface treatment in the surface treatment station 2 can be substantially eliminated, and a uniform amount of protrusion of silicon crystals can be obtained between the cylinder portions. In addition, the temperature difference between the cylinder parts at the end of the surface treatment can be substantially eliminated.

Further, in this surface treatment system, in the surface treatment station 2, the cylinder portion temperature measuring device 18 measures the temperature of each cylinder portion once again after the surface treatment is completed, and based on the output signal BT of the measurement result, the post-cleaning station. 20
In consideration of the cooling from the end of the surface treatment to the post-cleaning and the cooling from the post-cleaning to the post-process, the controller of the liquid temperature management system 24 corresponding to In the same manner as the system 23, the liquid temperature of the cleaning liquid supplied to each cylinder in the post-cleaning station 20 is set to be lower than that of the cylinders of the second and third cylinders for the cylinders of the first and fourth cylinders whose temperature tends to decrease. The liquid temperature of the cleaning liquid in each of the cleaning liquid tanks of the cleaning liquid tank 22 is adjusted so that

Therefore, according to this surface treatment system, it is possible to eliminate the temperature difference between the cylinder parts even when performing the inspection in the post-process 11, and it is possible to avoid the occurrence of a measurement error between the cylinder parts due to the temperature difference, which in turn The measurement work can be made extremely easy.

Although the present invention has been described above based on the illustrated example, the present invention is not limited to the above-described example. For example, the takt time per work piece at each station in the surface treatment system is short, and only one station has a cylinder. If the temperature difference between the parts cannot be sufficiently eliminated, the temperature of both the cleaning liquid in the pre-cleaning station and the processing liquid in the surface treatment station may be controlled. In this way, each cylinder in the surface treatment station can be controlled. It is possible to obtain a sufficiently uniform protrusion amount of silicon crystals between the parts, and it is possible to sufficiently eliminate the temperature difference between the cylinder parts at the end of the surface treatment.

Further, the above-mentioned bore temperature measuring device is provided in the pre-cleaning station to measure the temperature difference between the cylinder parts immediately after the pre-cleaning,
Based on the measurement results, in consideration of the cooling from the machining process to the pre-cleaning and the cooling from the pre-cleaning to the surface treatment, the temperature of at least one of the cleaning liquid and the processing liquid is controlled for each cylinder. It is also possible to do so, and such a method can also bring about the same effect as the above-mentioned embodiment.

(Effect of the invention) Thus, according to the surface treatment method of the present invention, it is possible to obtain a uniform amount of protrusion of silicon crystals between the cylinder parts, and also to cause a temperature difference between the cylinder parts in the post-process after the post-cleaning. It is possible to prevent the trouble that occurs.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a surface treatment system used in an embodiment of a surface treatment method for an aluminum cylinder block of the present invention, and FIG. 2 is a surface treatment station, a treatment liquid tank, and a liquid temperature control system in the surface treatment system. And FIG. 3 is a configuration diagram showing the cylinder temperature measuring device in more detail. FIG. 3 shows the measurement result of the distribution state of the cylinder surface temperature after the pre-cleaning and before the surface treatment of an actual four-cylinder aluminum cylinder block, and in that case. FIG. 4 is a characteristic diagram showing an example of controlling the treatment liquid temperature for each cylinder portion, FIG. 4 is a configuration diagram illustrating a surface treatment system used in another embodiment of the present invention, and FIG. 5 is used in a conventional surface treatment method. FIG. 6 is a configuration diagram showing the surface treatment system, and FIG. 6 is a relational diagram showing the results of measurement of the relation between the temperature and concentration of the treatment liquid and the amount of protrusion of silicon crystals by a test. 1,19 …… Pre-cleaning station 2,12 …… Surface treatment station 4,15,21,22 …… Cleaning liquid tank 5,14 …… Treatment liquid tank 7,8,16,17,23,24 …… Liquid temperature Management system 10 …… Preprocess, 11 …… Post process 13,20 …… Post cleaning station 18 …… Cylinder temperature measuring device 25 …… Aluminum cylinder

Claims (2)

(57) [Claims] 1. A pre-cleaning step of pre-cleaning an inner surface of each cylinder portion of a multi-cylinder aluminum cylinder block with a cleaning liquid, and a chemical treatment step of chemically corroding the inner surface of each cylinder portion by filling a processing liquid. In the surface treatment method of sequentially performing the following steps, the temperature of each cylinder part is measured after the pre-cleaning in the pre-cleaning step and before the filling of the treatment liquid in the chemical treatment step. A surface treatment method for an aluminum cylinder block, characterized in that the liquid temperature of the treatment liquid in the chemical treatment step is controlled for each of the cylinder parts based on the measured temperature of each of the cylinder parts. 2. A pre-cleaning step of pre-cleaning the inner surface of each cylinder portion of a multi-cylinder aluminum cylinder block with a cleaning liquid, and a chemical treatment step of chemically corroding the inner surface of each cylinder portion by filling with a processing liquid. In the surface treatment method of sequentially performing the following steps, the temperature of each cylinder part is measured after the pre-cleaning in the pre-cleaning step and before the filling of the treatment liquid in the chemical treatment step. The liquid temperature of the cleaning liquid in the pre-cleaning step is sequentially controlled for each of the cylinder parts and for a plurality of the cylinder blocks based on the temperature of each of the cylinder parts that has been determined. , Surface treatment method of aluminum cylinder block.