Patent Application
20110030660
The present invention belongs to the field of the internal combustion engine and relates to the improvement of combustion in the combustion chamber of an internal combustion engine.
Patent Document 1 shows an internal combustion engine including a combustion/reaction chamber, auto-ignition means, microwave radiation means, and control means. The combustion/reaction chamber consists of a cylinder and piston. The combustion/reaction chamber is supplied with a mixture of reactive and oxidation gas. In the combustion/reaction chamber, a plasma reaction of the mixture is carried out. The auto-ignition means automatically ignites the mixture by injecting a mixture of reactive and oxidation gas under high pressure, compressing the mixture and increasing the temperature. The microwave radiation means radiates the combustion/reaction chamber with microwaves. The control means controls the auto-ignition means and microwave radiation means, and repeats a cycle that involves radiating the combustion/reaction chamber with microwaves so that large amounts of hydroxyl (OH) radicals and ozone (O3) are generated from the moisture in the combustion/reaction chamber mixture, which then oxidizes and reacts chemically, combustion of the mixture in the combustion/reaction chamber is promoted by the large amount of OH radicals and O3, when the auto-ignition, means ignites the mixture.
The internal-combustion engine with an electrical field formed in the combustion chamber is disclosed in Patent Documents 2 to 4. Patent Document 2 outlines an internal combustion engine, containing the following: a cylinder block with a cylinder wall; a cylinder head on the cylinder block; a piston in the cylinder block; a combustion chamber formed by the cylinder wall, cylinder head and piston; and an electrical field apply means for applying an electrical field in the combustion chamber during combustion of the engine. When an electrical field is applied to the flame in this internal combustion engine, ions move into the flame and collide. This increases the flame propagation speed, and the ions in the gas that has already burnt move to unburnt gas and alter the chemical reaction in the unburnt gas. This maintains a uniform flame temperature and controls engine knock.
The inventor of the present invention extrapolated the mechanism of combustion promotion in the internal combustion engine which is disclosed in Patent Document 1, and obtained a constant finding about the mechanism. In this mechanism, a small amount of plasma is discharged firstly. The plasma is irradiated with microwaves for a given period of time, so that the amount of plasma increases. Thus a large amount of OH radicals and ozone is generated from moisture in the air-fuel mixture within a short period of time, promoting an air-fuel mixture reaction. This mechanism of the combustion promotion, obtained by generating a large amount of OH radicals and ozone, promotes combustion with plasma, is entirely different from combustion-promoting mechanisms that use ions to increase flame propagation speed, disclosed in Patent Documents 2 through 4.
In the view of the foregoing, the present invention has been achieved. An object of the invention is to provide a multiple discharge plasma apparatus which promotes combustion by generating a large amount of OH radicals and ozone with plasma at multiple places to improve combustion in the combustion chamber.
The present invention is plasma apparatus using a valve, which is installed in an internal combustion engine in which a piston fits into a cylinder penetrating a cylinder block to reciprocate freely, a cylinder head is assembled to the anti-crankcase side of the cylinder block with a gasket between it and the cylinder block, an intake port opening on the cylinder head is opened and closed with an intake valve, an exhaust port opening on the cylinder head is opened and closed with an exhaust valve, these parts form the combustion chamber, the multiple discharge plasma apparatus comprises, a plurality of discharge devices, each with an electrode exposed to the combustion chamber and installed in at least one of members constituting the combustion chamber, an antenna installed in at least one of the members constituting the combustion chamber so as to radiate electromagnetic waves to the combustion chamber, an electromagnetic wave transmission line installed in at least one of the members constituting the combustion chamber, with one end connected to the antenna and the other end covered with an insulator or dielectric and extending to a portion, of at least one of the members constituting the combustion chamber, distant from the combustion chamber, and an electromagnetic wave generator for feeding electromagnetic waves into the electromagnetic wave transmission line, wherein the multiple discharge plasma apparatus is configured such that discharge is generated by the electrodes of a plurality of discharge devices and the electromagnetic waves fed from the electromagnetic wave generator through the electromagnetic wave transmission line are radiated from antenna, during the compression stroke when the intake valve closes the intake port and the exhaust valve closes the exhaust port.
At the compression stroke in the actuation of the internal combustion engine, discharges are generated by the electrodes of a plurality of discharge devices and the electromagnetic waves fed from the electromagnetic wave generator through the electromagnetic wave transmission line are radiated from the antenna. Therefore, the plasma is generated near the electrodes. This plasma receives energy of an electromagnetic waves (electromagnetic wave pulse) supplied from the antenna for a given period of time. As a result, the plasma generates a large amount of OH radicals and ozone to promote the combustion. In fact electrons near the electrodes are accelerated, fly out of the plasma area, and collide with gas such as air or the air-fuel mixture in surrounding area of said plasma. The gas in the surrounding area is ionized by these collisions and becomes plasma. Electrons also exist in the newly formed plasma. These also are accelerated by the electromagnetic wave pulse and collide with surrounding gas. The gas ionizes like an avalanche and floating electrons are produced in the surrounding area by chains of these electron acceleration and collision with electron and gas inside plasma. These phenomena spread to the area around discharge plasma in sequence, then the surrounding area get into plasma state. In the result of the phenomena as mentioned above it, the volume of plasma increases. Then the electrons recombine rather than dissociate at the time when the electromagnetic wave pulse radiation is stopped. As a result, the electron density decreases, and the volume of plasma decreases as well. The plasma disappears when the electron recombination is completed. A large amount of OH radicals and ozone is generated from moisture in the gas mixture as a result of a large amount of the generated plasma, promoting the combustion of the mixture.
In this case, a large amount of plasma beginning at each electrode is generated, because there are multiple electrodes of said discharge devices. A large amount of OH radicals and ozone are generated from moisture etc. in the gas mixture as a result of these multiple plasma, promoting the combustion of the mixture.
Moreover, ignition is caused in the vicinity of the cylinder wall when the electrodes are installed in the vicinity of the cylinder wall. This deduces or prevents the generation of knocking, which originates in an uncertain factor such as pressure waves that reach the cylinder wall from the vicinity of the center of the combustion chamber.
The multiple discharge plasma apparatus of the present invention may be applicable for which the multiple discharge plasma apparatus is configured such that discharge is generated by a plurality of the electrodes of the discharge devices in sequence following a predefined schedule.
This makes it possible that a large amount of plasma is generated near each electrode. A large amount of OH radical and ozone are generated as a result of plasma. As a result, combustion of mixture is promoted in each place. These phenomena near each electrode are initiated in sequence following a predefined schedule. Therefore, high-speed ignitions or combustions such as the volume ignition are initiated in sequence, and combustion reaction progresses according to this schedule.
The multiple discharge plasma apparatus of the present invention may be applicable for which the multiple discharge plasma apparatus is configured such that discharge is generated by a plurality of the electrodes of the discharge devices sequentially with the same timing.
This makes it possible that a large amount of plasma is generated near each electrode. A large amount of OH radical and ozone are generated as a result of plasma. As a result, combustion of mixture is promoted in each place with the same timing.
The multiple discharge plasma apparatus of the present invention may be applicable for which the multiple electrodes are located close to multiple portions that electric field intensity generated by the electromagnetic waves strengthens in the antenna when the electromagnetic waves are fed into the antenna.
This makes it possible that the electrical field intensity, due to the electromagnetic waves radiated from said each portion of the antenna, is stronger than the electrical field intensity of the surrounding electromagnetic waves. Therefore, the energy of the electromagnetic wave pulse from said each portion near the plasma is intensively supplied to the plasma generated by discharge at each electrode. As a result, a large amount of OH radicals and ozone is efficiently generated, further promoting combustion in the area centered at each electrode.
Hereinafter, embodiments of the present invention will be described.
The discharge device 810 with electrode 811 exposed to the combustion chamber 400 is installed in the cylinder block 100, as shown in
Antenna 820 is installed in cylinder block 100 to radiate the electromagnetic waves into combustion chamber 400, as shown in
Electromagnetic wave transmission line 830 is installed in cylinder block 100. One of the electromagnetic wave transmission lines 830 is connected with the antenna 820. The other end of electromagnetic wave transmission line 830 is covered with a dielectric, and extends to a portion of the cylinder block 100, distant from the combustion chamber 400. The wall of cylinder 110 in cylinder block 110 contains a hole that penetrates the wall from periphery side of second support 130 to the outside wall. The third support 140 with tube-shaped is installed in this hole. This third support 140 is made from ceramics. Like this, the third support 140 may be made from dielectric, but it may be made from insulator. One of the third support 140 ends is connected with a side which is farther from cylinder 110 on the second support 130. The other end of the third support 140 reaches the outside wall of cylinder block 100. And electromagnetic wave transmission line 830 is installed in the third support 140. The electromagnetic wave transmission line 830 is made from copper wire. The electromagnetic wave transmission line 830 may be made from conductor, dielectric, or insulator and so on. However, electromagnetic waves must be transmitted well to the antenna 820 upon supplying electromagnetic waves between the earthed member and the electromagnetic wave transmission line. A variation example of the electromagnetic waves transmission line is an electromagnetic waves transmission line which consists of a waveguide made from conductor or dielectric. Here, the electromagnetic wave transmission line 830 is buried in the third support 140, and pass through the third support 140. One end of the electromagnetic wave transmission line 830 is connected with the antenna 820. The other end of the electromagnetic wave transmission line 830 is extracted from the outside wall of cylinder block 100 to outside. Thus, when electromagnetic waves are supplied between electromagnetic wave transmission line 830 and cylinder block 100 that is the earth member, they are introduced into antenna 820.
Electromagnetic wave generator 840 supplies the electromagnetic waves to transmission line 830, and is installed in internal combustion engine E or its surroundings. Electromagnetic wave generator 840 in this embodiment is a magnetron that generates 2.4-GHz-bandwidth microwaves. However, this does not restrict the construction of the electromagnetic wave generator of the multiple discharge plasma apparatus in the present invention.
In this multiple discharge plasma apparatus, discharge is generated between the electrodes of a plurality of discharge devices, and electromagnetic waves fed from the electromagnetic wave generator through the electromagnetic wave transmission line are radiated from the antenna 820, at the compression stroke when the intake valves closes the intake ports and the exhaust valves closes the exhaust ports. In the multiple discharge plasma apparatus in this embodiment, discharge is generated by a plurality of the electrodes 811 of the discharge devices 810 in sequence following a predefined schedule (Refer to
As a modification, there is a multiple discharge plasma apparatus that is configured such that discharge is generated by a plurality of the electrodes 810 of the discharge devices 810 sequentially with the same timing.
At the compression stroke in the actuation of the internal combustion engine E, discharges are generated by the electrodes of a plurality of discharge devices 810 and the electromagnetic waves fed from the electromagnetic wave generator 840 through the electromagnetic wave transmission line 830 are radiated from the antenna 820. Therefore, the plasma is generated near electrodes 811. This plasma receives energy of an electromagnetic waves (electromagnetic wave pulse) supplied from the antenna 820 for a given period of time. As a result, the plasma generates a large amount of OH radicals and ozone to promote the combustion. In fact electrons near electrodes are accelerated, fly out of the plasma area, and collide with gas such as air or the air-fuel mixture in surrounding area of said plasma. The gas in the surrounding area is ionized by these collisions and becomes plasma. Electrons also exist in the newly formed plasma. These also are accelerated by the electromagnetic wave pulse and collide with surrounding gas. The gas ionizes like an avalanche and floating electrons are produced in the surrounding area by chains of these electron acceleration and collision with electron and gas inside plasma. These phenomena spread to the area around discharge plasma in sequence, then the surrounding area get into plasma state. In the result of the phenomena as mentioned above it, the volume of plasma increases. Then the electrons recombine rather than dissociate at the time when the electromagnetic wave pulse radiation is stopped. As a result, the electron density decreases, and the volume of plasma decreases as well. The plasma disappears when the electron recombination is completed. A large amount of OH radicals and ozone is generated from moisture in the gas mixture as a result of a large amount of the generated plasma, promoting the combustion of the mixture.
In this case, a large amount of plasma beginning at each electrode 811 is generated, because there are multiple electrodes 811 of said discharge devices 810. A large amount of OH radicals and ozone are generated from moisture etc. in the gas mixture as a result of these multiple plasma, promoting the combustion of the mixture.
Moreover, ignition is caused in the vicinity of the cylinder wall when the electrodes 811 are installed in the vicinity of the cylinder wall. This deduces or prevents the generation of knocking, which originates in an uncertain factor such as pressure waves that reach the cylinder wall from the vicinity of the center of the combustion chamber.
In the multiple discharge plasma apparatus of the present invention, the order of operating the electrical discharge device etc. is not restricted. In the multiple discharge plasma apparatus in first embodiment discharge is generated by a plurality of the electrodes of the discharge devices in sequence following a predefined schedule. This makes it possible that a large amount of plasma is generated near each electrode 811. A large amount of OH radical and ozone are generated as a result of plasma. As a result, combustion of mixture is promoted in each place. These phenomena near each electrode 811 are initiated in sequence following a predefined schedule. Therefore, high-speed ignitions or combustions such as the volume ignition are initiated in sequence, and combustion reaction progresses according to this schedule.
Moreover, when discharge is generated by a plurality of the electrodes 811 of the discharge devices 810 sequentially with the same timing, a large amount of plasma is generated near each electrode 811 with the same timing. A large amount of OH radical and ozone are generated as a result of plasma with the same timing. As a result, combustion of mixture is promoted in each place with the same timing.
The positional relationship between the antenna and the electrodes is not restricted in the multiple discharge plasma apparatus of the present invention. Multiple electrodes 811 are respectively located close to a portion of strong electrical field intensity in the antenna 820 due to the electromagnetic waves when the electromagnetic waves are fed to the antenna 820 in the first embodiment among such varied embodiments. This makes it possible that the electrical field intensity, due to the electromagnetic waves radiated from said each portion of the antenna 820, is stronger than the electrical field intensity of the surrounding electromagnetic waves. Therefore, the energy of the electromagnetic wave pulse is intensively supplied to the plasma generated by discharge at the electrodes 811. As a result, a large amount of OH radicals and ozone is efficiently generated, further promoting combustion in the area centered at the electrodes 811.
Next, other embodiments of the multiple discharge plasma apparatus of the present invention will be described. In the multiple discharge plasma apparatus in first embodiment, discharge devices 810, antenna 820, and electromagnetic wave transmission line 830 were installed in the cylinder block 100 of the members constituting the combustion chamber 400. In the multiple discharge plasma apparatus in second embodiment, discharge devices 760, antenna 770, and electromagnetic wave transmission line 780 were installed in the gasket 700 of the members constituting the combustion chamber 400.
Hereinafter, second embodiments, including modifications, of the multiple discharge plasma apparatus will be described.
Gasket 700, shown in
As shown in
As shown in
As shown in
Gasket 700 electrically insulates discharge line 760, antenna 770, electromagnetic wave transmission line 780, and both surfaces of the gasket in thickness direction. Cylinder block 100, cylinder head 300, or surface layer 740 is earthed. The anode of discharge voltage generator 950 is connected to first connector 761. The anode of electromagnetic wave generator 840 is connected to second connector 781. The earth terminals of discharge voltage generator 950 and electromagnetic wave generator 840 are earthed. Discharge voltage generator 950 and electromagnetic wave generator 840 are controlled by controller 880, which has a CPU, memory, and storage etc, and outputs control signals after computing input signals. A signal line from crank angle detector 890 for detecting crank angle of crankshaft 920 is connected to control unit 880. Crank angle detection signals are sent from crank angle detector 890 to controller 880. Therefore, controller 880 receives signals from crank angle detector 890 and controls the actuations of discharge device 760 and electromagnetic wave generator 840. Discharge voltage generator 950 in this embodiment is a 12-V DC power source, but this can also be a piezo element or other device. Electromagnetic wave generator 840 generates electromagnetic waves. Electromagnetic wave generator 840 in this embodiment is a magnetron that generates 2.4-GHz-bandwidth microwaves. However, this does not restrict the control method and the composition of the input-output signals as for gasket of the present invention.
Therefore, the gasket is installed between the cylinder block 100 and cylinder head 300 so that its opening 710 corresponds to the cylinder 110. A piston 200 fits into the cylinder 110 and reciprocates freely. The internal combustion engine E operating normally as a gasoline engine is assembled up. It makes possible to apply voltage between first connector 761 of the discharge line 760 and the earth member. It makes possible to feed electromagnetic waves between the second connector 781 and the earth member for a constant time. And voltage is applied to the first connector 761 of the discharge line 760 and the earthed member. The electromagnetic waves are fed to the second connector 781 of the electromagnetic wave transmission line and the earthed member at the compression stroke, when the intake valves 510 close the intake ports 310 and exhaust valves 520 closing the exhaust ports 320, in the actuation of the internal combustion engine E. Therefore, the plasma is generated near the electrode 762. This plasma receives energy of an electromagnetic waves (electromagnetic wave pulse) supplied from the antenna 770 for a given period of time. As a result, the plasma generates a large amount of OH radicals and ozone to promote the combustion. In fact electrons near the electrode 762 are accelerated, fly out of the plasma area, and collide with gas such as air or the air-fuel mixture in surrounding area of said plasma. The gas in the surrounding area is ionized by these collisions and becomes plasma. Electrons also exist in the newly formed plasma. These also are accelerated by the electromagnetic wave pulse and collide with surrounding gas. The gas ionizes like an avalanche and floating electrons are produced in the surrounding area by chains of these electron acceleration and collision with electron and gas inside plasma. These phenomena spread to the area around discharge plasma in sequence, then the surrounding area get into plasma state. In the result of the phenomena as mentioned above it, the volume of plasma increases. Then the electrons recombine rather than dissociate at the time when the electromagnetic wave pulse radiation is stopped. As a result, the electron density decreases, and the volume of plasma decreases as well. The plasma disappears when the electron recombination is completed. A large amount of OH radicals and ozone is generated from moisture in the gas mixture as a result of a large amount of the generated plasma, promoting the combustion of the mixture.
In this case, the cylinder block 100 and cylinder head 300 etc. which are the major structural materials can be used without modification compared with existing internal combustion engine. All that is required are the applying of voltage to the discharge line 760 and the supply of the electromagnetic waves. Thus, it is realized to minimize the time required to design an engine E and facilitate the sharing of many parts between existing internal combustion engines.
The material of surface layers on both sides of intermediate layer in thickness direction is not restricted in the gasket of the internal combustion engine of the present invention. The surface layers may also be a dielectric or insulator. In the gasket of the second embodiment, intermediate layer 730 is made from a dielectric, and surface layers 740 on both sides of intermediate layer 730 in thickness direction are made from a conductive material among such varied embodiments. Thus, surface layer 740 works as an earth electrode that pairs with electrode 762 of discharge line 760. The discharge is generated between electrode 762 and surface layer 740. Surface layer 740 also works as an earth conductive material that pairs with electromagnetic wave transmission line 780. The electromagnetic waves are transmitted between electromagnetic wave transmission line 780 and surface layer 740. If the intermediate layer is made from an insulator and the surface layers on both sides of the intermediate layer are made from a conductive material, the same function and effect are also gained. Moreover, if the intermediate layer is made from a dielectric or insulator and the surface layer on at least one side of the intermediate layer is made from a conductive material, the same function and effect are also gained. Additionally, the rigidity of gasket 700 improves because surface layer 740 is made from metal.
The structure and the shape of the antenna are not restricted in the gasket of the internal combustion engine of the present invention. The antenna 770 is rod-shaped as for the gasket 700 in the second embodiment among such varied embodiments. The base end of the antenna 770 is installed in the intermediate layer 730 in thickness direction. A portion, to the leading end except the base end, extends along the inner peripheral edge around the opening 710 in the circumferential direction of the opening 710 in the antenna 770. This makes it possible that the electrical field intensity near the outer edge of the combustion chamber 400, generated by the electromagnetic waves radiated from the antenna 770, is stronger than the electrical field intensity in other areas of the combustion chamber 400. Therefore, the amount of OH radicals and ozone in the vicinity of the outer edge of the combustion chamber 400 is more than the amount of other areas. Combustion in this area is promoted more than in other areas. Mixing of OH radicals or ozone and the air-fuel mixture is promoted by Squish Flow, Tumble or Swirl in the vicinity of the outside edge of the combustion chamber 400.
The positional relationship between the antenna and the electrode is not restricted in the gasket of the internal combustion engine of the present invention. Electrode 762 is located close to a portion of strong electrical field intensity in the antenna 770 due to the electromagnetic waves when the electromagnetic waves are fed to the antenna 770 in the second embodiment among such varied embodiments. This makes it possible that the electrical field intensity, due to the electromagnetic waves radiated from said portion of the antenna 770, is stronger than the electrical field intensity of the surrounding electromagnetic waves. Therefore, the energy of the electromagnetic wave pulse is intensively supplied to the plasma generated by discharge at the electrode 762. As a result, a large amount of OH radicals and ozone is efficiently generated, further promoting combustion in the area centered at the electrode 762. When there are multiple areas of the antenna 770 with strong electrical field intensity, combustion at multiple areas of the combustion chamber 400 is further promoted upon the portion approaching to the electrode 762.
Next, modifications of the gasket of the present invention will be described in the following paragraphs. In the description of the gasket of these modifications, members and portions, which fulfill the same function as the gasket 700 in the second embodiment, will be applied to the same reference characters used in the second embodiment. The description of these members and portions will be omitted. And, difference points of the composition from the gasket 700 in the second embodiment will be explained about the gaskets of these modifications. Therefore, the composition without the description is the same as the composition of the gasket 700 in the second embodiment.
In the case of third modification, a large amount of plasma beginning at each electrode 762 is generated, because there are multiple electrodes 762 of said discharge devices 760. A large amount of OH radicals and ozone are generated from moisture etc. in the gas mixture as a result of these multiple plasma, promoting the combustion of the mixture.
Moreover, ignition is caused in the vicinity of the cylinder wall when the electrodes 762 are installed in the vicinity of the cylinder wall. This deduces or prevents the generation of knocking, which originates in an uncertain factor such as pressure waves that reach the cylinder wall from the vicinity of the center of the combustion chamber.
In the multiple discharge plasma apparatus of the present invention, the order of operating the electrical discharge device etc. is not restricted. In the multiple discharge plasma apparatus in second embodiment discharge is generated by a plurality of the electrodes of the discharge devices in sequence following a predefined schedule. This makes it possible that a large amount of plasma is generated near each electrode 762. A large amount of OH radical and ozone are generated as a result of plasma. As a result, combustion of mixture is promoted in each place. These phenomena near each electrode 762 are initiated in sequence following a predefined schedule. Therefore, high-speed ignitions or combustions such as the volume ignition are initiated in sequence, and combustion reaction progresses according to this schedule.
Moreover, when discharge is generated by a plurality of the electrodes 762 sequentially with the same timing, a large amount of plasma is generated near each electrode 762 with the same timing. A large amount of OH radical and ozone are generated as a result of plasma with the same timing. As a result, combustion of mixture is promoted in each place with the same timing.
The positional relationship between the antenna and the electrodes is not restricted in the multiple discharge plasma apparatus of the present invention. Multiple electrodes 762 are respectively located close to a portion of strong electrical field intensity in the antenna 770 due to the electromagnetic waves when the electromagnetic waves are fed to the antenna 770 in the second embodiment among such varied embodiments. This makes it possible that the electrical field intensity, due to the electromagnetic waves radiated from said each portion of the antenna 770, is stronger than the electrical field intensity of the surrounding electromagnetic waves. Therefore, the energy of the electromagnetic wave pulse is intensively supplied to the plasma generated by discharge at each electrode 762. As a result, a large amount of OH radicals and ozone is efficiently generated, further promoting combustion in the area centered at each electrodes 762.
In the gasket of the present invention, a pair of the electrodes or the earth member pair with this may be covered with a dielectric. In this case, the dielectric-barrier discharge is generated by voltage applied between the electrodes or between the electrode and the earth member. The dielectric-barrier discharge is restricted because charges are accumulated in the surface of the dielectric covering the electrode or the earth member. Therefore, the discharge is generated on a very small scale over a very short period of time. Thermalization does not occur in the area surrounding the discharge because the discharge is terminated after a short period of time. Therefore, the gas temperature rise due to the discharge between the electrodes is reduced, which reduces the amount of NOx produced by the internal combustion engine.
The material that installs the electromagnetic wave transmission line changes according to the material that installs the antenna, and becomes the cylinder block or a cylinder head.
The present invention includes some embodiments that combine the characteristics of the embodiments described above. Moreover, the embodiments described above are only examples of multiple discharge plasma apparatus of the present invention. Thus, the description of these embodiments does not restrict interpretation of multiple discharge plasma apparatus of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-066889 | Mar 2008 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2009/054965 | Mar 2009 | US |
| Child | 12881917 | US |
