JP2010184180A - Method of cleaning cylinder head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of cleaning a cylinder head which allows preventing effluence of foreign matter remaining in the water jacket of a cylinder head during operation of the engine. <P>SOLUTION: The cleaning method includes a cleaning process S1 of selecting one of holes communicating with the water jacket 1, i.e. an inlet 3, an outlet 4, communicating holes 5 injecting a cleaning solution into the water jacket 1 from the selected hole and discharging the cleaning solution from a hole other than the selected hole. The cleaning process S1 has, as the last process, the first cleaning process S10 of causing the cleaning solution to flow in the same direction as the flowing direction of a cooling liquid within the water jacket 1 during operation of the engine. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a cylinder head cleaning method, and more particularly to a cleaning technique for a water jacket formed on a cylinder head.

A water jacket is formed in a cylinder head of a water-cooled engine (hereinafter simply referred to as “engine”) in order to circulate the coolant. During engine operation, the engine is well cooled by circulating a coolant through the water jacket.
In addition, the water jacket is designed so that the flow rate of the coolant passing through a part that requires cooling in the engine, such as the vicinity of the valve, is increased based on the functional role of cooling the engine. It is known to be formed as a narrow portion.

The cylinder head is generally formed by casting, and a hollow water jacket is formed therein by using a core or the like during casting. After the casting process, machining such as drilling for forming a bolt hole in the cylinder head and cutting of the mounting surface of the cylinder head is performed.
A cleaning process for cleaning the outer surface of the cylinder head and the inside of the water jacket is performed before assembling the cylinder head through the casting process, the machining process, and the like. At this time, it is necessary to sufficiently remove foreign matters such as metal pieces and chips remaining inside, so that they do not flow into and enter other parts.

For example, in Patent Document 1, any one of a plurality of holes provided in the cylinder head and communicating between the inside and outside of the water jacket faces the cleaning liquid outlet, and the other hole faces the compressed gas outlet. A cleaning method is disclosed in which cleaning liquid and compressed gas are supplied into the water jacket from the cleaning liquid outlet and the compressed gas outlet, respectively, and foreign matters in the water jacket are led out from the remaining holes to the outside.
According to this, since the turbulent flow of the cleaning liquid and the compressed air is generated in the water jacket, the foreign matters remaining inside can be efficiently discharged to the outside.
However, the cleaning method disclosed in Patent Document 1 does not consider the flow direction in the water jacket when the engine is in operation, and therefore, foreign substances clogged in the narrow portion of the water jacket of the cylinder head having a complicated shape and flow path are removed. If it cannot be removed, the foreign matter may flow out along the flow of the coolant in the water jacket during actual operation of the engine, which may cause a problem on the downstream side.

JP 61-153187 A

  It is an object of the present invention to provide a cylinder head cleaning method capable of preventing outflow of foreign matters remaining in a water jacket of a cylinder head during engine operation.

  The cylinder head cleaning method according to claim 1 is a cylinder head cleaning method for cleaning a cylinder head provided in an engine and having a water jacket therein. The cylinder head cleaning method is provided in the cylinder head. By selecting one of a plurality of holes communicating with the water jacket, injecting a cleaning liquid into the water jacket from the selected hole, and discharging the cleaning liquid from a hole different from the selected hole. Among the washing steps for washing the first washing step, the first washing step in which the washing liquid is circulated in the same direction as the flow direction of the cooling liquid during engine operation in the water jacket is defined as the final step.

  According to a second aspect of the present invention, in the cylinder head cleaning method, it is preferable that the flow rate of the cleaning liquid is set larger than the flow rate of the cooling liquid when the engine is operating.

  The cylinder head cleaning method according to claim 3, further comprising a second cleaning step of circulating the cleaning liquid in the water jacket in a direction opposite to a flow direction of the cleaning liquid in the first cleaning step. It is preferable to repeat the first cleaning step and the second cleaning step a plurality of times in order before the final step.

  According to a fourth aspect of the present invention, in the cylinder head cleaning method, it is preferable to increase the flow rate of the cleaning liquid as the process proceeds to a subsequent process.

  6. The cylinder head cleaning method according to claim 5, wherein the hole is different from each hole selected in the cleaning step, and is in the vicinity of a water jacket portion corresponding to a cooling required portion of the cylinder head. It is preferable to select a hole to be arranged and additionally inject a cleaning liquid into the water jacket from the selected hole with respect to the cleaning liquid injected in the cleaning step.

  According to the present invention, it is possible to prevent the foreign matter remaining in the water jacket of the cylinder head from flowing out during engine operation.

It is a schematic diagram which shows a cylinder head. It is a schematic diagram which shows a water jacket. It is a schematic diagram which shows the aspect of the washing | cleaning liquid supply in the washing | cleaning process of a water jacket. It is a flow which shows the washing process of a water jacket. It is a schematic diagram which shows the washing | cleaning process of a water jacket.

  Below, with reference to FIGS. 1-2, the water jacket 1 which is one Embodiment of the water jacket which concerns on this invention is demonstrated. The water jacket 1 is a space formed in a cylinder head 2 provided in an in-line four-cylinder water-cooled engine (hereinafter simply referred to as an “engine”), and a coolant supplied from a water pump is circulated therein. This is a cooling structure for cooling the engine. In addition, devices such as intake and exhaust valves and spark plugs are disposed at predetermined positions of the cylinder head 2.

  As shown in FIG. 1, the water jacket 1 is provided with an inlet 3 serving as an inflow path for cooling liquid and an outlet 4 serving as an outflow path for cooling liquid at both end portions. A coolant flow is formed in one direction of the water pump → inlet 3 → outlet 4. In addition to the inflow port 3 and the outflow port 4, a plurality of communication holes 5 and the like are provided at appropriate locations as holes that communicate the inside and outside of the water jacket 1 in the cylinder head 2.

The flow path structure in the water jacket 1 (for example, a structure having flow path characteristics such as flow direction determined by the arrangement of the inflow port 3 and the outflow port 4) is provided for each device disposed in the cylinder head 2. Designed for optimal cooling.
For example, as shown in FIG. 2, in the water jacket 1, there is a narrow portion having a small channel cross-sectional area in the vicinity of a portion requiring cooling in the cylinder head 2 (for example, a portion that is likely to become high temperature during actual operation of the engine, such as an intake / exhaust valve). It is formed as 6.6. In FIG. 2, for convenience of explanation, the narrow portion 6 is displayed in two places, but in reality, almost all the portions in the vicinity of the required cooling portion in the cylinder head 2 in the water jacket 1 are included in the narrow portion 6. It is formed as.
In this way, by forming the portion of the water jacket 1 corresponding to the required cooling site where high cooling performance is required in the cylinder head 2 as the narrow portion 6, the coolant when passing through the narrow portion 6. It is designed to increase the flow rate of and improve the cooling performance.

By the way, the cylinder head 2 is a cast product formed by casting, and after the casting process, machining such as cutting and drilling is performed to obtain a product.
When assembling the cylinder head 2 to the engine, it is necessary to remove foreign matter adhering to the surface of the cylinder head 2 or remaining in the water jacket 1 during the cylinder head manufacturing process in order to guarantee the quality of the product. .
For this reason, a submerging process for submerging the cylinder head 2 to remove foreign substances, a cleaning process S1 for removing the foreign substances inside the water jacket 1 by passing a cleaning liquid through the water jacket 1 and the like are performed. In particular, the cleaning step S1 is a step of cleaning the water jacket 1 using a predetermined cleaning liquid in order to discharge foreign matters such as chips generated in the machining step and remaining in the water jacket 1 from the water jacket 1. is there.

As shown in FIG. 3, in the cleaning step S1 for cleaning the water jacket 1, a first nozzle 11 for injecting a cleaning liquid from the inlet 3 side and a second nozzle 12 for injecting a cleaning liquid from the outlet 4 side are used. Done. The first nozzle 11 and the second nozzle 12 can be independently operated such as supplying a cleaning liquid.
The first nozzle 11 and the second nozzle 12 can be sealingly connected to the inflow port 3 and the outflow port 4, respectively, and are configured to be able to adjust the flow rate of the cleaning liquid to be injected. For example, the discharge portions of the first nozzle 11 and the second nozzle 12 are formed in shapes corresponding to the diameters of the inflow port 3 and the outflow port 4, respectively, and around the discharge portions are sealed for preventing liquid leakage. A member is disposed. The first nozzle 11 and the second nozzle 12 are connected to supply means such as a pump and a valve (not shown), and the flow rate thereof can be freely adjusted by opening and closing the valve, adjusting the output of the pump, and the like.

As shown in FIG. 3, when cleaning using the first nozzle 11 or the second nozzle 12, holes such as the communication holes 5, 5... Other than the inlet 3 and the outlet 4 of the water jacket 1 are plugged. It is plugged and sealed separately by masking. However, the communication hole 5 to which an auxiliary nozzle 15 described later is connected is sealed by the auxiliary nozzle 15.
When cleaning is performed using the first nozzle 11, the cleaning liquid injected from the inlet 3 is discharged from the outlet 4, and a flow of cleaning liquid from the inlet 3 to the outlet 4 is formed. When cleaning is performed using the second nozzle 12, the cleaning liquid injected from the outlet 4 is discharged from the inlet 3, and a flow of cleaning liquid from the outlet 4 to the inlet 3 is formed.
Further, the flow rate of the cleaning liquid injected by the first nozzle 11 and the second nozzle 12 is set to be larger than the flow rate of the cooling liquid when the engine is actually operated. The "flow rate of coolant during actual operation of the engine" is a flow rate that guarantees the cooling performance required during actual operation of the engine, and depends on the discharge amount of a water pump (not shown) that supplies the coolant. .

Further, as shown in FIG. 3, an auxiliary nozzle 15 for injecting a cleaning liquid into the water jacket 1 from the communication hole 5 disposed in the vicinity of the narrow portions 6, 6... Of the water jacket 1 is provided.
The auxiliary nozzle 15 can be sealed and connected to the communication hole 5, and the flow rate of the cleaning liquid to be injected can be adjusted. The injection of the cleaning liquid from the auxiliary nozzle 15 is performed simultaneously with the injection of the cleaning liquid in the first cleaning step S10 and / or the second cleaning step S20.
As described above, the cleaning liquid injected from the auxiliary nozzle 15 partially adds a flow rate to the flow of the cleaning liquid injected from the first nozzle 11 or the second nozzle 12. By adding the flow rate from the auxiliary nozzle 15, a partial increase in flow rate (especially an increase in flow rate for the narrow portion 6) can be expected.

Below, with reference to FIGS. 4-5, washing | cleaning process S1 which wash | cleans the water jacket 1 is demonstrated.
As shown in FIG. 4, the cleaning step S <b> 1 includes a first cleaning step S <b> 10 in which the cleaning liquid is circulated from the inlet 3 of the water jacket 1 toward the outlet 4, and from the outlet 4 of the water jacket 1 toward the inlet 3. The first cleaning step S10 and the second cleaning step S20 constitute one cleaning cycle S30.
As shown in FIG. 4, in the cleaning step S1, this cleaning cycle S30 is repeated a plurality of times (three times in the present embodiment), and the first cleaning step S10 is the final step.
In this embodiment, the cleaning cycle S30 is repeated three times. However, the number of repetitions may be plural, and can be set as appropriate with reference to a desired cleaning effect, a cleaning result, and the like.

As shown in FIG. 5A, in the first cleaning step S <b> 10, the first nozzle 11 is sealed and connected to the inflow port 3 to inject the cleaning liquid, and the second nozzle 12 is separated from the outflow port 4. At this time, the flow rate of the cleaning liquid injected from the first nozzle 11 is set to be larger than the flow rate of the cooling liquid during engine operation. Further, as described above, the holes other than the outlet 4 (communication holes 5, 5...) In the water jacket 1 are appropriately closed, so that the cleaning liquid flows from the inlet 3 to the outlet 4. , Discharged from the outlet 4.
In other words, the flow direction of the cleaning liquid in the first cleaning step S10 is the same direction as the flow direction of the cooling liquid in the water jacket 1 during engine operation.

As shown in FIG. 5B, in the second cleaning step S <b> 20, the second nozzle 12 is sealed and connected to the outlet 4 to inject the cleaning liquid, and the first nozzle 11 is separated from the inlet 3. At this time, the flow rate of the cleaning liquid injected from the second nozzle 12 is set to be larger than the flow rate of the cooling liquid during engine operation. Further, as described above, in the water jacket 1, holes other than the inlet 3 (communication holes 5, 5...) Are appropriately closed, so that the cleaning liquid flows from the outlet 4 to the inlet 3. , And discharged from the inlet 3.
That is, the flow direction of the cleaning liquid in the second cleaning step S20 is opposite to the flow direction of the cooling liquid in the water jacket 1 during engine operation.

As described above, the cleaning step S1 is the same as the first cleaning step S10 in which the flow direction of the cleaning liquid is the same direction as the flow direction of the cooling liquid in the water jacket 1 when the engine is operating. This is a cleaning cycle in which the cleaning liquid is circulated from both directions including the second cleaning step S20 in the reverse direction.
According to this, since a bidirectional force can be applied to foreign matter such as chips and metal pieces clogged at an arbitrary location in the water jacket 1, the foreign matter can be effectively removed. In particular, since a large flow of cleaning liquid can be applied from both directions to the narrow portion 6 of the water jacket 1 where foreign substances are easily clogged, clogging is eliminated regardless of the clogging direction of the foreign substances and discharged outside the water jacket 1. it can.
Further, in the cleaning step S1, the cleaning liquid is circulated by using the channel structure of the water jacket 1 whose channel characteristics are optimally designed as it is. For this reason, the minimum flow rate necessary for cleaning in the water jacket 1 can be generated over the entire range, and no special flow rate control is required for a portion where the foreign matter such as the narrow portion 6 is likely to be clogged. Can be realized.
Further, in the cleaning step S <b> 1, holes other than the inlet 3 and the outlet 4 of the water jacket 1 are plugged and sealed, so that the cleaning liquid discharge port is limited to the inlet 3 and the outlet 4. Therefore, the cleaning liquid does not leak to the outside and is not wasted, and the cleaning liquid can be used efficiently.

Further, in the cleaning process S1, the first cleaning process S10 in which the cleaning liquid flows in the same direction as the flow direction of the cooling liquid in the water jacket 1 during engine operation is the final process.
According to this, even when the foreign matter clogged in the narrow portion 6 or the like cannot be removed, the foreign matter is cooled by applying a force by flowing the cleaning liquid from the same direction as the flow direction of the cooling liquid during actual operation of the engine. The narrow portion 6 can be tightly packed along the liquid flow direction. Therefore, the possibility that foreign matter is mixed into the coolant flowing in the water jacket 1 during engine operation is reduced, and outflow of foreign matter from the water jacket 1 can be suppressed. As a result, high quality assurance for the engine can be realized.

Further, the flow rate of the cleaning liquid in the first cleaning process S10 and the second cleaning process S20 is set to be larger than the flow rate of the cooling liquid when the engine is actually operated.
According to this, even when the foreign matter clogged in the narrow portion 6 or the like cannot be removed, the flow of the cooling liquid applied during engine operation is weaker than the flow of the cleaning liquid applied to the foreign matter during cleaning. For this reason, the possibility that the foreign matter moves due to the flow of the coolant during actual operation of the engine is reduced, and the outflow of the foreign matter can be suppressed. As a result, high quality assurance for the engine can be realized.
It should be noted that the flow rate of the cleaning liquid is preferably sufficiently larger than the flow rate of the cooling liquid from the viewpoint of removing foreign substances and preventing the movement of foreign substances, and in particular, considering the cleaning effect, energy efficiency, etc. It is preferable that the flow rate is about several times the flow rate.

In the cleaning step S <b> 1, in addition to the injection of the cleaning liquid by the first nozzle 11 and the second nozzle 12, the cleaning liquid is added from the auxiliary nozzle 15, thereby partially increasing the flow rate with respect to the narrow portion 6.
According to this, since the flow rate of the cleaning liquid with respect to the narrow portion 6 which is a site requiring cleaning in the cleaning step S1 can be easily controlled, the flow rate in the narrow portion 6 can be increased by a desired amount. Accordingly, energy efficiency related to the cleaning liquid injection can be improved, and foreign matters clogged in the narrow portion 6 can be reliably removed.

In the cleaning step S1, the cleaning cycle S30 including the first cleaning step S10 and the second cleaning step S20 is repeated a plurality of times. According to this, the foreign matter clogged in the narrow part 6 etc. can be removed and discharged more reliably.
At this time, when the first cleaning step S10 and the second cleaning step S20 (cleaning cycle S30) are repeated, the flow rate of the cleaning liquid may be gradually increased as it becomes a subsequent step.
That is, when the cleaning cycle S30 is repeated, the cleaning ability is gradually increased by increasing the flow rate, and the certainty of removing foreign matters can be improved.
In the first cleaning step S10, which is the final step, the flow rate is the maximum, so even when foreign matter clogged in the narrow portion 6 or the like cannot be removed, the same direction as the coolant flow direction during engine operation Since a larger force can be applied by flowing the cleaning liquid from the above, it is possible to pack more firmly along the flow direction of the cooling liquid.

The first nozzle 11 and the second nozzle 12 are configured to move in conjunction with each other. At the time of transition between the first cleaning step S10 and the second cleaning step S20, the first before the cleaning liquid in the water jacket 1 is completely discharged. Replacement of the nozzle 11 and the second nozzle 12 may be completed. For example, when the injection of a predetermined amount (or a predetermined time) of the cleaning liquid by the first nozzle 11 is completed, the first nozzle 11 is separated from the inlet 3. At this time, the second nozzle 12 is moved together with the separation of the first nozzle 11. It is good also as a structure connected to the outflow port 4 interlockingly. The same applies when the second nozzle 12 is separated from the outlet 4.
According to this, the cleaning liquid remaining in the replacement of the first nozzle 11 and the second nozzle 12 can be reused without discharging and replacing all the cleaning liquid in one process, and thus the usage efficiency of the cleaning liquid can be improved. .

Moreover, you may perform washing | cleaning process S1, with the 1st nozzle 11 and the 2nd nozzle 12 sealingly connected to the inflow port 3 and the outflow port 4, respectively.
That is, a state in which a pump for supplying the cleaning liquid to the first nozzle 11 and the second nozzle 12 is made common, a valve is provided in the supply path to each of the nozzles 11 and 12, and a predetermined amount of the cleaning liquid is stored in the water jacket 1. Then, by switching the valve, the cleaning liquid is circulated from the first nozzle 11 side in the first cleaning step S10 to form the flow of the inlet 3 → the outlet 4 or in the second cleaning step S20. It is good also as a structure which distribute | circulates a washing | cleaning liquid from the 2 nozzle 12 side and forms the flow of the outflow port 4-> inflow port 4. FIG.
According to this, since the cleaning liquid is not discharged to the outside, the usage efficiency of the cleaning liquid can be improved.

In general, it has been found that it is unlikely that a clogged item could be removed and clogged again elsewhere. This is because the uncontrollable factors such as the angle and speed with respect to the clogged portion are working, and clogging itself is a strong factor of chance.
That is, there is a low possibility that the foreign matter clogged in the narrow portion 6 etc. will be clogged with other parts again, so that it is not necessary to consider re-clogging of the foreign matter, and for the purpose of removing the foreign matter, The cleaning liquid can be used efficiently by retaining or circulating the liquid.

The object to be cleaned by the cleaning step S1 is not limited to the water jacket 1, but may be any that has directionality in the flow channel structure, in particular, one that is designed to be directed in a direction in which the flow channel cross-sectional area is small. This is particularly effective for a workpiece that is cleaned from a plurality of directions according to the directionality.
That is, the cleaning step S1 selects one of the plurality of holes provided in the workpiece and injects the cleaning liquid from the selected hole, and at least in the flow direction in which design consideration is made. It can be applied as long as it includes a step of flowing.

Further, in addition to the existing flow path structure existing in the work such as the water jacket 1, a cleaning communication hole may be newly provided and the cleaning hole may be used.
In other words, when cleaning is performed using the existing flow path structure of the workpiece, if cleaning efficiency, energy efficiency, etc. deteriorate, a new communication hole for cleaning will be provided in consideration of these efficiencies only during cleaning. It is good also as a structure which uses and closes at the time of actual work (after a workpiece | work assembly | attachment). For example, when applied to a water jacket in which the flow path structure is curved, a cleaning hole is formed at a location where the flow path is substantially linear to realize a linear flow path for the cleaning liquid. For example, a substantially uniform flow velocity distribution is realized in the cross section of the flow path.

1 Water jacket 2 Cylinder head 3 Inlet (hole)
4 Outlet (hole)
5. Communication hole (hole)
6 Narrow part (cooling part required)
11 First nozzle 12 Second nozzle 15 Auxiliary nozzle

Claims (5)

A cylinder head cleaning method for cleaning a cylinder head provided in an engine and having a water jacket therein,
Select one of a plurality of holes provided in the cylinder head and communicated with the water jacket, and inject the cleaning liquid into the water jacket from the selected hole, and from a hole different from the selected hole Of the washing process of washing the water jacket by discharging the washing liquid,
A cylinder head cleaning method, wherein a final cleaning step is a first cleaning step in which the cleaning liquid is circulated in the same direction as the flow direction of the cooling liquid during engine operation in the water jacket.   The cylinder head cleaning method according to claim 1, wherein a flow rate of the cleaning liquid is set to be larger than a flow rate of the cooling liquid during actual operation of the engine. A second cleaning step of circulating the cleaning liquid in the water jacket in a direction opposite to the flow direction of the cleaning liquid in the first cleaning step;
The cylinder head cleaning method according to claim 1 or 2, wherein the first cleaning step and the second cleaning step are sequentially repeated a plurality of times before the final step.   The cylinder head cleaning method according to any one of claims 1 to 3, wherein the flow rate of the cleaning liquid is increased as the process proceeds to a subsequent process. A hole that is different from each hole selected in the cleaning step, and is selected in the vicinity of the water jacket portion corresponding to the cooling required portion of the cylinder head,
The cylinder head cleaning method according to any one of claims 1 to 4, wherein a cleaning liquid is additionally injected into the water jacket from the selected hole with respect to the cleaning liquid injected in the cleaning step. .

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