Patent Application
20210102511
The present invention relates to a piston forming a combustion chamber of an internal-combustion engine, and more particularly to an internal-combustion engine piston including a heat insulating layer formed on a combustion chamber-side top face of a piston body and a method for controlling cooling of the piston.
In an internal-combustion engine such as a gasoline engine, a part of heat generated by combustion is discharged from the inside of a combustion chamber to the outside through a piston or a cylinder wall and the like to cause a cooling loss. In order to improve the thermal efficiency of the internal-combustion engine, it is necessary to reduce the cooling loss. Therefore, the following technique, a so-called temperature swing heat shield method has been known. A layer having a low thermal conductivity and a low heat capacity is formed on a combustion chamber-side top face of a piston body occupying a relatively large area in a wall surface of a combustion chamber, whereby the surface temperature of the top face of the piston body is caused to follow an in-cylinder combustion gas temperature with a small time delay to reduce a heat flux on the surface of the piston.
In the following description, the top face is mentioned, including a surface forming the combustion chamber, which is formed on the top face of the piston body. Therefore, the top face of the piston body means the combustion chamber-side surface of the piston body.
Meanwhile, when fuel droplets adhere to the top face of the piston body thus reduced in a heat capacity, the piston temperature of the adhering portion decreases, so that the vaporization performance of the fuel deteriorates, which causes a decreased thermal efficiency. Furthermore, this leads to an increase in harmful components in exhaust gas such as soot particles (PM) and unburned hydrocarbon (HC) particularly at the time of cold start.
Therefore, in order to achieve both an improvement in thermal efficiency and a reduction in exhaust gas harmful components, the following technique is disclosed in JP 2013-67823 A (Patent literature 1). An anodic oxide layer having a low thermal conductivity and a low heat capacity is formed on the top face of a piston body, and a metal skin layer having a relatively higher heat capacity than that of the anodic oxide layer is disposed on the surface of a fuel injection region in the anodic oxide layer.
PTL 1: JP 2013-67823 A
In the meantime, as described also in Patent Literature 1, the anodic oxide layer having a low thermal conductivity and a low heat capacity is formed on the top face of the piston body, and the metal skin layer having a relatively higher heat capacity than that of the anodic oxide layer is disposed on the surface of the fuel injection region in the anodic oxide layer. This may cause an excessive increase in the temperature of the metal skin layer having a high heat capacity during the combustion of an air-fuel mixture, which causes the occurrence of abnormal combustion such as knocking or pre-ignition.
Therefore, a piston suppressing the abnormal combustion such as knocking and pre-ignition, and a cooling control method cooling the piston are required to be developed.
An object of the present invention is to provide a novel internal-combustion engine piston which makes it possible to achieve both an improvement in thermal efficiency and a reduction in exhaust gas harmful components, and to suppress the occurrence of abnormal combustion such as knocking and pre-ignition, and a method for controlling cooling of the piston.
A first feature of the present invention lies in that a piston body includes a cooling passage formed therein; and a first heat shielding layer and a second heat shielding layer are formed on a top face of the piston body, wherein the first heat shielding layer is composed of a material having a lower thermal conductivity and volumetric specific heat than those of a piston base material, the second heat shielding layer is composed of a material having a lower thermal conductivity and volumetric specific heat than those of the first heat shielding layer, and a first separation distance between the first heat shielding layer and the cooling passage is set to be less than a second separation distance between the second heat shielding layer and the cooling passage.
According to a second aspect of the present invention lies in that cooling medium variable supply means for supplying a cooling medium into the cooling passage of the piston body, and changing a flow rate of the cooling medium is provided, wherein an amount of cooling medium supplied to the cooling passage is changed by the cooling medium variable supply means based on a cooling water temperature or a lubricating oil temperature of the internal-combustion engine.
According to the present invention, a cooling loss can be reduced by the second heat shielding layer, and the vaporization of fuel adhering to the top face of the piston body can be promoted by the first heat shielding layer to reduce exhaust gas harmful components. Since the first separation distance between the first heat shielding layer and the cooling passage is less than the second separation distance between the second heat shielding layer and the cooling passage, the first heat shielding layer is efficiently cooled by the cooling passage. Therefore, the temperature of the first heat shielding layer does not rise excessively, whereby the occurrence of abnormal combustion such as knocking and pre-ignition can be suppressed.
Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments, and various modification examples and application examples are included within the technical concept of the present invention.
Hereinafter, a form of a piston according to a first embodiment of the present invention and an internal-combustion engine including the piston will be described with reference to the drawings.
Also, a fuel injection valve 5 is provided in an intake port 1, and an injection nozzle thereof penetrates into the intake port. The fuel injection valve 5 constitutes a so-called port injection type internal-combustion engine. An exhaust port 2 for discharging combustion gas of the combustion chamber 9 is provided, and a spark plug 6 for igniting an air-fuel mixture is provided.
A first heat shielding layer 101 and a second heat shielding layer 102 are provided on a combustion chamber-side surface of a top face of the piston body 100 formed of a piston base material 100m. The first heat shielding layer 101 and the second heat shielding layer 102 form a part of the combustion chamber 9.
Here, in the comparison between the first heat shielding layer 101 and the second heat shielding layer 102, the first heat shielding layer 101 is composed of a thin plate material or a coating material and the like having “a low thermal conductivity and high volumetric specific heat”. The first heat shielding layer 101 desirably has a thermal conductivity of 1 to 10 W/mK, volumetric specific heat of 1000 kJ/m3K or more, and a thickness of 200 μm or more. The second heat shielding layer 102 is composed of a thin plate material or a coating material and the like having “a low thermal conductivity and low volumetric specific heat”. The second heat shielding layer 102 desirably has a heat conductivity of 0.5 W/mK or less, volumetric specific heat of 500 kJ/m3K or less, and a thickness of 50 to 200 μm.
Furthermore, the piston base material 100m is composed of an aluminum alloy, iron, or a titanium alloy and the like, and has a thermal conductivity of about 50 to 200 W/mK and volumetric specific heat of about 2000 to 3000 kJ/m3K. Therefore, the thermal conductivity has the relationship of piston base material>first heat shielding layer>second heat shielding layer, and the volumetric specific heat has the relationship of piston base material>first heat shielding layer>second heat shielding layer.
Here, the first heat shielding layer 101 having “a low thermal conductivity and high volumetric specific heat” has a function of hardly transmitting heat and easily retaining heat (greater heat capacity). The second heat shielding layer 102 having “a low thermal conductivity and low volumetric specific heat” has a function of hardly transmitting heat and having a quick heat response (small heat capacity). The reason why the thermal conductivity of the second heat shielding layer 102 is set to be less than the thermal conductivity of the first heat shielding layer 101 is that heat transfer from the second heat shielding layer 102 is reduced (heat shieldability is improved) to reduce a cooling loss. Specific materials and the like of the first heat shielding layer 101 and the first heat shielding layer 102 will be described later.
Returning to
The flow rate of the cooling oil supplied to the cooling oil jet nozzle 201 is adjusted by a valve opening degree command value 205 of a controller 204 on the cooling oil flow rate adjustment valve 202. The controller 204 receives information such as a lubricating oil temperature and cooling water temperature of the engine detected by a temperature sensor (not shown). As described above, in the internal-combustion engine of the present Examples, the piston body 100 is cooled by using a so-called cooling channel.
In the present embodiment, the first heat shielding layer 101 is disposed on the top face of the piston body 100 in the vicinity of the cooling passage 200, so that the relationship between the average separation distance Lm1 between the first heat shielding layer 101 and the cooling passage 200 and the average separation distance Lm2 between the second heat shielding layer 102 and the cooling passage 200 satisfies Lm1<Lm2. In order to cause the average separation distance to satisfy Lm1<Lm2, for example, as shown in
In order to cause the average separation distance to satisfy Lm1<Lm2, for example, when the moving direction of the piston body 100 to the bottom dead point side is a lower side, at least a part of a lower surface of the first heat shielding layer 101 is desirably located below a lower surface of the second heat shielding layer 102.
As shown in
Since the second heat shielding layer 102 is composed of a material having “a low thermal conductivity and low volumetric specific heat”, its surface temperature follows a change in a combustion gas temperature in the combustion chamber with a small time delay and a small temperature difference. That is, in the middle stage of the intake stroke to the middle stage of the compression stroke, an in-cylinder gas temperature decreases due to the introduction of new air into the combustion chamber, whereby the surface temperature of the second heat shielding layer 102 accordingly decreases. Furthermore, in the later stage of the compression stroke to the exhaust stroke, the in-cylinder gas temperature rises due to the compression and combustion of the in-cylinder gas, whereby the surface temperature of the second heat shielding layer 102 accordingly rises.
As described above, in the second heat shielding layer 102, the surface temperature changes following the in-cylinder gas temperature, whereby the amount of heat transfer between the in-cylinder gas and the wall surface of the top face of the piston body 100 is reduced, which makes it possible to reduce the cooling loss of the engine. This is a so-called heat loss reduction method referred to as a temperature swing heat shielding method.
Meanwhile, since the first heat shielding layer 101 is composed of a material having “a low thermal conductivity and high volumetric specific heat”, its surface temperature is usually higher than the surface temperature of the piston, but it hardly follows a change in the in-cylinder gas temperature in a combustion cycle in the combustion chamber. For this reason, the change width of the surface temperature in one combustion cycle of the first heat shielding layer 101 is less than the change width of the surface temperature of the second heat shielding layer 102.
For example, while the change width of the surface temperature in the combustion cycle of the second heat shielding layer 102 is about 500° C., the change width of the surface temperature in the combustion cycle of the first heat shielding layer 101 is about 50° C. As a result, the surface temperature of the first heat shielding layer 101 tends to be higher than the surface temperature of the second heat shielding layer 102 and the surface temperature of the normal piston in the middle stage of the intake stroke to the middle stage of the compression stroke.
When the engine temperature is low, such as immediately after the cold start of the engine, the temperature of the air-fuel mixture near the wall surface of the combustion chamber including the top face of the piston body 100 is low, whereby the thickness of extinction in the vicinity of the wall surface increases, so that more unburned hydrocarbon is discharged. In the case where the engine temperature is low even when fuel droplets adhere to the wall surface, the evaporation thereof is slow, so that the discharge amount of unburned hydrocarbon increases. In particular, when only the second heat shielding layer 102 composed of the material having “a low thermal conductivity and low volumetric specific heat” is provided on the top face of the piston body 100 in order to reduce the cooling loss, the surface temperature is lower than the normal surface temperature in the intake stroke to the compression stroke, so that the discharge amount of unburned hydrocarbon at the time of cold further increases.
Meanwhile, when the first heat shielding layer 101 composed of the material having “a low thermal conductivity and high volumetric specific heat” is additionally provided, the temperature of the surface of the first heat shielding layer 101 in the intake stroke to the compression stroke is high, so that the heat causes a high temperature of in-cylinder gas containing unburned components in the vicinity of the surface of the first heat shielding layer 101. In the high temperature in-cylinder gas, the thickness of the extinction becomes thinner, and the vaporization of the droplets adhering to the surface of the first heat shielding layer 101 is promoted. These effects reduce the discharge amount of unburned hydrocarbon. Thus, both the first heat shielding layer 101 and the second heat shielding layer 102 are provided on the top face of the piston body 100, which makes it possible to reduce the exhaust gas harmful components at the time of cold, and to reduce the cooling loss to improve the fuel consumption of the engine.
Meanwhile, the first heat shielding layer 101 is composed of the material having “a low thermal conductivity and high volumetric specific heat”, so that the temperature of the first heat shielding layer 101 rises as the number of combustions increases to cause the temperature of the engine to rise. This causes an excessively high temperature of unburned gas in the vicinity of the surface of the first heat shielding layer 101, which may accordingly cause abnormal combustion such as knocking or pre-ignition.
In the present embodiment, a state causing abnormal combustion such as knocking or pre-ignition is estimated from the fact that the cooling water temperature or the lubricating oil temperature has reached a predetermined temperature. When the cooling water temperature or the lubricating oil temperature is higher than the predetermined temperature, the piston body 100 is cooled by the cooling oil jet. In the present embodiment, the separation distance between the cooling passage 200 of the piston body 100 and the first heat shielding layer 101 is less than the separation distance between the cooling passage 200 of the piston body 100 and the second heat shielding layer 102.
Generally, thermal resistance between two points in a solid is inversely proportional to a distance between the two points, whereby the cooling effect of the cooling passage 200 on the heat shielding layer is stronger as the separation distance between the cooling passage 200 and the heat shielding layer is smaller. Therefore, while the first heat shielding layer 101 is strongly cooled by the cooling passage 200, the cooling effect of the cooling passage 200 on the second heat shielding layer 102 is small.
In the present embodiment, when the cooling water temperature or the lubricating oil temperature is lower than a predetermined temperature, the cooling of the cooling oil jet on the piston body 100 is stopped by the stop of the injection of the cooling oil or the decrease of the flow rate, or the cooling effect is weakly controlled, whereby the temperature of the first heat shielding layer 101 at the time of cold of the engine does not decrease, which can provide an improved reduction effect of the exhaust gas harmful components.
The temperature of the in-cylinder gas is generally highest at the center of the combustion chamber, and decreases toward the outer peripheral wall of the combustion chamber. Therefore, the second heat shielding layer 102 provided near the central part of the top face of the piston body provides a higher effect of reducing the cooling loss. Meanwhile, the temperature of the in-cylinder gas is low on the outer peripheral side of the combustion chamber, so that extinction or insufficient vaporization of the fuel is apt to occur. Therefore, the first heat shielding layer 101 is provided on the outer peripheral side of the combustion chamber, in other words, on the side of the region where the radius of the combustion chamber is large, and the temperature of the top face of the piston body on the outer peripheral side is risen, which provides a higher effect of reducing the exhaust gas harmful components.
The unburned gas on the outer peripheral side of the combustion chamber is compressed for self-ignition causes knocking, so that it is effective to cool the outer peripheral side of the combustion chamber in order to prevent the knocking. For this reason, the cooling passage 200 and the first heat shielding layer 101 are desirably disposed in a circular shape or an arc shape near the outer peripheral side of the piston body 100.
In the present embodiment, the relationship between the average separation distance Lm1 between the first heat shielding layer 101 and the cooling passage 200 and the average separation distance Lm2 between the second heat shielding layer 102 and the cooling passage 200 satisfies Lm1<Lm2. However, the overlapping ratio between the first heat shielding layer 101 and the cooling passage 200 may be greater than the overlapping ratio between the second heat shielding layer 102 and the cooling passage 200.
More specifically, as shown in
When the overlapping ratio between the first heat shielding layer 101 and the cooling passage 200 is taken as “S11/S10” and the overlapping ratio between the second heat shielding layer 102 and the cooling passage 200 is taken as “S21/S20”, it is effective to satisfy the following equation.
Therefore, it is necessary to define the arrangements and sizes of the first heat shielding layer 101, the second heat shielding layer 102, and the cooling passage 200 such that the overlapping ratio of the first heat shielding layer 101 is greater than the overlapping ratio of the second heat shielding layer 102. As described above, when the overlapping ratio between the heat shielding layer and the cooling passage is great, the cooling effect of the cooling passage is improved. Therefore, when the overlapping ratio of the first heat shielding layer 101 is greater than the overlapping ratio of the second heat shielding layer 102, the first heat shielding layer 101 is more strongly cooled by the cooling passage 200 than the second heat shielding layer 102 is.
As described above, according to the present embodiment, by the second heat shielding layer having “a low thermal conductivity and low volumetric specific heat”, the cooling loss is reduced, and by the first heat shielding layer having “a low thermal conductivity and high volumetric specific heat”, the vaporization of the fuel adhering to the piston body can be promoted to reduce the exhaust gas harmful components. The first separation distance between the first heat shielding layer and the cooling passage is less than the second separation distance between the second heat shielding layer and the cooling passage, whereby the first heat shielding layer is efficiently cooled by the cooling passage, to prevent the temperature of the first heat shielding layer from excessively rising, which makes it possible to suppress the occurrence of abnormal combustion such as knocking or pre-ignition. Furthermore, the cooling of the cooling passage on the second heat shielding layer can be suppressed to prevent the increase in the cooling loss.
Next, a second embodiment of the present invention will be described with reference to
Furthermore, in the top face of the piston body 100, a cavity 103 recessed toward a bottom dead point side is provided. A first heat shielding layer 101 is provided on the bottom part of the cavity 103, and a second heat shielding layer 102 is provided on the top face of the piston body 100 outside the cavity 103. When viewed from the combustion chamber side in the sliding direction of the piston body 100, the cavity 103 and a cooling passage 200 are disposed such that the cavity 103 and at least a part of the cooling passage 200 overlap.
When the temperature of an engine is low such as immediately after at the time of cold start of the engine, fuel is injected from the fuel injection valve 5 toward the cavity 103 in the late stage of a compression stroke, whereby an air-fuel mixture having a high fuel concentration is formed in the vicinity of an electrode part of a spark plug 6. This provides improved ignitability of the air-fuel mixture, whereby stable combustion is performed even when an ignition timing is retarded as compared with that during a normal operation, which provides efficient temperature rising of an exhaust gas purification catalyst (not shown) by high temperature exhaust gas associated with the ignition retardation. Furthermore, at the time of cold, the temperature of the first heat shielding layer 101 provided on the bottom face of the cavity 103 rises, whereby a fuel liquid layer formed on the bottom face of the cavity 103 is vaporized in a short time, which suppresses the discharge of unburned hydrocarbon and soot.
When viewed from the combustion chamber side in the sliding direction of the piston body 100, the cavity 103 and the cooling passage 200 are disposed such that the cavity 103 and at least a part of the cooling passage 200 overlap, whereby the first heat shielding layer 101 provided on the bottom face of the cavity 103 is efficiently cooled by the cooling passage 200 after the warm-up of the engine to suppress the occurrence of abnormal combustion such as knocking or pre-ignition.
In order to more efficiently cool the first heat shielding layer 101 provided on the bottom face of the cavity 103 and to reduce a cooling loss from the second heat shielding layer 102, it is effective to make the width of the cooling passage 200 on the side of the cavity 103 greater than the width of the cooling passage 200 in other portion to increase a heat transfer area between the cavity 103 and the cooling passage 200.
It is desirable to provide an opening part (inlet side) 200A for taking in a cooling oil for cooling the piston body on the side of the cavity 103, and to dispose an opening part (outlet side) 200B for discharging the cooling oil on the opposite side of the cavity 103. In this case, the side of the cavity 103 is the side of an inlet, which provides a low cooling oil temperature, and the opposite side of the cavity 103 is the side of an outlet, which provides a high cooling oil temperature. Therefore, the first heat shielding layer 101 provided on the bottom face of the cavity 103 is efficiently cooled, and the cooling of the second heat shielding layer 102 is suppressed.
In the piston applied to the in-cylinder direct injection internal-combustion engine, the first heat shielding layer 101 is locally provided on the top face of the piston body 100 on which the fuel liquid layer is formed, whereby the vaporization of the injected fuel can be efficiently promoted, and the area of the second heat shielding layer 102 can be maximized to reduce the cooling loss. For this purpose, as shown in
Furthermore, it is desirable to define the positions of the cooling passage 200 and first heat shielding layer 101, and the direction of the fuel spray 20 such that an average distance Lm1 between the first heat shielding layer 101 and the cooling passage 200 is less than an average distance Lm2 between the second heat shielding layer 102 and the cooling passage 200. By setting the overlapping ratio between the first heat shielding layer 101 and the cooling passage 200 to be greater than the overlapping ratio between the second heat shielding layer 102 and the cooling passage 200, the first heat shielding layer 101 after warm-up can be efficiently cooled.
When the fuel injection valve 5 is constituted by a porous nozzle, and a plurality of fuel sprays are formed, as shown in
As shown in
Furthermore, when the plurality of first heat shielding layers 101 are provided, as shown in
As described above, when at least one of the first heat shielding layers 101 is the first heat shielding layer 101 disposed on the exhaust side of the combustion chamber, the exhaust-side first heat shielding layer 101 having a higher temperature is close to the cooling passage 200, whereby the first heat shielding layer 101 is strongly cooled, which is more effective in suppressing abnormal combustion such as knocking and pre-ignition.
Furthermore, in order to reduce fuel consumption and CO2 in recent years, so-called idling stop control is widely adopted, in which the operation of the engine is stopped when the vehicle is temporarily stopped. During idling stop, the first heat shielding layer 101 having great volumetric specific heat is maintained at a high temperature. For this reason, air in the vicinity of the surface of the first heat shielding layer 101 is heated, which causes pre-ignition when the engine is restarted. In order to prevent the pre-ignition, it is effective to supply a cooling oil from a cooling oil jet nozzle into the cooling passage 200 of the piston body during idling stop to cool the first heat shielding layer 101. In this case, the cooling oil may be supplied by an electric pump.
Next, the configurations of the first and second heat shielding layers 101 and 102 described above will be described in detail with reference to
Hereinafter, both the first heat shielding layer 101 and the second heat shielding layer 102 will be described as a surface layer.
A ratio of a volume occupied by the void 137 contained in the matrix 130 and the hole 135 contained in the hollow particles 134 in the surface layer 100s is referred to as “a porosity”. By increasing the porosity, the thermal conductivity and volumetric specific heat of the surface layer 100s can be reduced. Therefore, the porosity of the first heat shielding layer 101 is set to be less than that of the second heat shielding layer 102 in order to increase the thermal conductivity and volumetric specific heat of the first heat shielding layer 101 as compared to those of the second heat shielding layer 102. When the surface layer 100s constitutes the first heat shielding layer 101, the porosity is set to, for example, about 20% in order to provide a low thermal conductivity and high volumetric specific heat. Meanwhile, when the surface layer 100s constitutes the second heat shielding layer 102, the porosity is set to, for example, about 50% in order to provide a low thermal conductivity and low volumetric specific heat.
In order that the surface layer 100s withstands a severe environment (high temperature, high pressure, strong vibration) in the internal-combustion engine, high adhesion to a base material 100m and high tensile strength are required for the surface layer 100s. By using the matrix 130 constituting the main portion of the porous surface layer 100s as the metal layer 136, high adhesion and high durability between the metal base material 100m and the surface layer 100s can be obtained.
The hollow particles 134 are contained in the void 137 of the matrix 130, and the void 137 in the matrix 130 is combined with the hole 135 of the hollow particles 134, whereby the volume amount of the void 137 in the matrix 130 is suppressed while the porosity required for lowering the thermal conductivity is secured, which allows the strength of the surface layer 100s to be highly kept.
The metal layer 136 is preferably composed of a sintered metal in which metal particles are bonded by sintering.
It is preferable that the metal layer 136 and the base material 100m contain the same metal as a main component thereof. Specifically, it is preferable that the base material 100m is composed of an aluminum (Al) alloy and the metal layer 136 is composed of aluminum (Al). As described above, the base material 100m and the metal layer 136 constituting the main portion of the surface layer 130 are composed of the same metal, whereby a robust solid phase bonding part is formed at the interface between the base material 100m and the surface layer 100s having a porous structure to secure high adhesion, which can achieve the surface layer 100s having excellent durability.
The material of the hollow particles 134 preferably has a small thermal conductivity and high strength even if it is hollow in order to secure the heat insulation performance of the surface layer 130. Examples of the material include silica, alumina, and zirconia. Examples of the hollow particles containing silica as a main component include ceramic beads, silica aerogel, and porous glass.
As described above, according to the present invention, the cooling passage is formed in the piston body; the first heat shielding layer composed of a material having a lower thermal conductivity and volumetric specific heat than those of the piston base material, and the second heat shielding layer composed of a material having a lower thermal conductivity and volumetric specific heat than those of the first heat shielding layer are provided on the top face of the piston body; and the first separation distance between the first heat shielding layer and the cooling passage is set to be less than the second separation distance between the second heat shielding layer 102 and the cooling passage 200. Variable cooling medium supply means for supplying a cooling medium into the cooling passage of the piston body and changing the flow rate of the cooling medium is provided, to cause the variable cooling medium supply means to change the supply amount of cooling medium to the cooling passage based on the cooling water temperature or lubricating oil temperature of the internal-combustion engine.
Therefore, the second heat shielding layer reduces the cooling loss, and the first heat shielding layer promotes the vaporization of the fuel adhering to the piston body, whereby the exhaust gas harmful components can be reduced. The first separation distance between the first heat shielding layer and the cooling passage is less than the second separation distance between the second heat shielding layer and the cooling passage, whereby the first heat shielding layer is efficiently cooled by the cooling passage, to prevent the temperature of the first heat shielding layer from rise excessively. This can suppress the occurrence of abnormal combustion such as knocking or pre-ignition.
The present invention is not limited to the above-described Examples, and various modifications are included therein. For example, the above-described Examples are described in detail for convenience of explanation and good understanding of the present invention, and thus the present invention is not limited to one having all the described configurations. Additionally, it is possible to replace a part of the configuration of certain Example with the configuration of another Example, and it is also possible to add the configuration of certain Example to the configuration of another Example. Further, regarding a part of the configuration of each Example, addition of another configuration, its deletion, and replacement with another configuration can be performed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-085920 | Apr 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/015347 | 4/12/2018 | WO | 00 |
