JP6090303B2 - engine - Google Patents

Description

  The present invention relates to an engine in which friction is reduced by levitation of one member with respect to the other member in a sliding portion.

  Conventionally, it has been desired to further improve the fuel efficiency performance and output performance of the engine. For this purpose, for example, it is effective to reduce the frictional resistance of each sliding portion in the engine. As a method for reducing the frictional resistance of the sliding portion, Patent Document 1 discloses that the sliding portion includes a sliding member and a sliding member provided with a predetermined low friction layer on a sliding surface of the sliding member. When the relative speed between the two members is equal to or higher than a predetermined speed, the sliding member is brought into a non-contact state with respect to the sliding member and is brought into a floating state. A method for reducing resistance is disclosed.

  In this case, the surface of the coating layer coated with CVD diamond or DLC is partially mirror-polished so that the height of the minute island portions to be mirror-polished becomes the same height. It is formed by doing. When the relative speed between the two members reaches a predetermined speed, the sliding member is in a floating state with respect to the sliding member.

JP 2006-144799 A

  By the way, when the low friction layer of Patent Document 1 is applied to each sliding portion in the engine, various problems arise. That is, as the engine sliding portion, for example, the cylinder inner surface and piston ring, the main shaft portion of the crankshaft and the bearing portion of the cylinder block, the small end portion of the connecting rod and the piston pin, and the large end portion of the connecting rod and the pin portion of the crankshaft. is there. However, foreign matter such as blow-by gas and unburned gas blown out from the combustion chamber to the cylinder and crank chamber side may remain in the engine, and adhesion of the foreign matter to the sliding surface becomes a problem. .

  For example, when the low friction layer is provided on sliding members such as a crankshaft, a piston ring, and a piston pin disposed in a cylinder or a crank chamber, the foreign matter may adhere to the low friction layer. As a result, the surface property of the low friction layer changes and the sliding resistance of the low friction layer increases, so that the levitation effect may be reduced or lost.

  The present invention has been made to solve the above problems when a friction reducing method by levitation is used for a sliding portion, and removes foreign matter adhering to the sliding surface, so that one member is replaced with the other member. An object of the present invention is to provide an engine capable of sustaining the levitation effect of levitation.

  In order to solve the above problems, the present invention is configured as follows.

First, the invention according to claim 1 of the present application includes a first member and a second member that moves relative to the first member, and at least one member of the first member and the second member. of the sliding surface, the relative speed of the two members has a low friction layer friction reduction process is applied to levitate the one of the members when the above predetermined relative to the other member, an engine, said friction The reduction process is a process for levitation without requiring lubricating oil, and the low friction layer is a plurality of convex portions having a top surface roughness Ra of 0.1 μm or less, each having the same high A plurality of protrusions formed on the protrusion, and a plurality of recesses located around the protrusions and having a depth of 3 to 10 μm. Featuring a deposit removing means for removing the adhered foreign matter To do.

According to a second aspect of the present invention, in the engine according to the first aspect, the first member is a piston ring provided on a piston, and the second member is a cylinder, deposit removal means, said heat-insulating layer der provided around the low-friction layer is, the inner surface of the cylinder, in a state where the piston is located at the top dead center, the heat insulating combustion chamber side from the piston ring layer is formed, that has the low friction layer in the anti-combustion chamber side from the piston ring is formed, characterized in that.

According to a third aspect of the present invention, in the engine according to the first aspect, the first member is a piston ring provided on a piston, and the second member is a cylinder, The deposit removing means is a low friction layer that also acts as a heat insulating layer on the inner surface of the cylinder .

The invention according to claim 4 is the air supply means in the engine according to claim 1, wherein the deposit removing means jets air from the sliding surface to the outside of the sliding surface. The air supply means communicates the air pump, the air pump and the plurality of sliding surfaces of the engine, and supplies air from the air pump to the plurality of sliding surfaces. a supply path that has a, characterized in that.

According to a fifth aspect of the present invention, in the engine according to the fourth aspect , the plurality of sliding surfaces are first slides configured between a crank journal outer peripheral surface and a main bearing inner peripheral surface. , A second sliding portion configured between the outer peripheral surface of the crank pin and the inner peripheral surface of the connecting rod large end portion, and a third sliding configured between the inner peripheral surface of the connecting rod small end portion and the outer peripheral surface of the piston pin And a fourth sliding portion configured between the piston ring and the inner surface of the cylinder, and the air supply path communicates the air pump and the inner peripheral surface of the main bearing, A second air passage formed in the air passage, the crankshaft, and communicating with the outer peripheral surface of the crank journal and the outer peripheral surface of the crank pin; and formed in the connecting rod; Connected to the inner peripheral surface of the small end of the connecting rod A third air passage, and the air discharged from the air pump passes from the piston through the first air passage, the second air passage, and the third air passage. It is characterized by being ejected on the inner surface of the cylinder .

According to a sixth aspect of the present invention, in the engine according to the fourth or fifth aspect, a predetermined amount is applied to the sliding surface based on a difference integrated value obtained by integrating the difference between the target torque and the actual torque. When the extraneous foreign matter is detected or estimated, the extraneous matter removing means is activated.

  According to the invention of each claim of the present application, the following effects can be obtained by the above configuration.

First, according to the first aspect of the present invention, when the relative speed between the first member and the second member is equal to or higher than a predetermined speed, dynamic pressure is generated in the recess, and one member is generated by the dynamic pressure. The levitation effect that levitates with respect to the other member is obtained. As a result, the frictional resistance between the first member and the second member is greatly reduced, and lubrication with lubricating oil is unnecessary. Since the foreign matter adhering to the sliding surface is removed by the deposit removing means, the surface property of the sliding surface can be maintained and an increase in frictional resistance can be suppressed. Therefore, the levitation effect of levitation of one member relative to the other member can be maintained.

  Further, according to the invention described in claim 2, by providing the heat insulating layer, the cooling loss from the combustion chamber to the outside of the combustion chamber is reduced, and as a result, the temperature of the combustion chamber can be increased, thereby The foreign matter adhering to the wall surface of the combustion chamber is burned. Therefore, the foreign matter adhering to the piston ring or the cylinder inner surface facing the combustion chamber is removed. Therefore, the surface property of the sliding surface between the piston ring and the cylinder can be maintained and increase in frictional resistance can be suppressed.

Further, according to the invention described in claim 3, as in the invention described in claim 2, the foreign matter adhering to the wall surface of the combustion chamber is burned. Accordingly, foreign matters adhering to the piston ring or the inner surface of the cylinder facing the combustion chamber are removed, so that an increase in frictional resistance can be suppressed while maintaining the surface properties of the sliding surface.

According to the fourth aspect of the present invention, air is ejected from the sliding surface to the outside of the sliding surface at the plurality of sliding portions of the engine by the air supply means. Intrusion is prevented. Therefore, the foreign material adhering to the sliding surface is removed.

According to the invention described in claim 5, the first sliding portion formed between the outer peripheral surface of the crank journal and the inner peripheral surface of the main shaft, between the outer peripheral surface of the crank pin and the inner peripheral surface of the connecting rod large end portion. In the second sliding portion configured, the third sliding portion configured between the inner peripheral surface of the connecting rod small end portion and the piston pin, and the fourth sliding portion configured between the piston ring and the inner surface of the cylinder. Since air is ejected from the sliding surface to the outside of the sliding surface, entry of foreign matter into each sliding surface is prevented. Therefore, accumulation of foreign matter on the sliding surface can be suppressed.

According to the invention described in claim 6, when it is detected or estimated that a foreign matter exceeding a predetermined amount has adhered to the sliding surface, the foreign matter removing means is actuated so as to adhere to the sliding surface. Foreign matter can be removed more efficiently. In addition, the amount of foreign matter adhering to the combustion chamber can be accurately detected based on the difference between the target torque and the actual torque. Therefore, the accumulation of foreign matter on the sliding surface can be more efficiently suppressed.

  In other words, according to the engine of the present invention, when the friction reducing method by levitation is used for the engine, the levitation effect of removing the foreign matter adhering to the sliding surface and levitation of one member with respect to the other member. Can be sustained.

It is sectional drawing which shows schematic structure of the main motion system of the engine which concerns on 1st Embodiment of this invention. It is a figure which expands and shows the low sliding layer to which the friction reduction process was performed. It is an enlarged view of the combustion chamber which shows the modification of a heat insulation layer. It is an enlarged view of the combustion chamber which shows the modification of a heat insulation layer. It is sectional drawing which shows schematic structure of the main motion system of the engine which concerns on 2nd Embodiment. It is sectional drawing which shows schematic structure of the main motion system of the engine which concerns on 3rd Embodiment. It is sectional drawing in the VII-VII line of FIG. It is sectional drawing of the engine which shows an example of the air supply path | route in multiple cylinders. It is a block diagram which shows schematic structure of the control system which concerns on 4th Embodiment. It is a flowchart which shows the action | operation of the engine system which concerns on 4th Embodiment. It is a time chart which shows the action | operation of the engine system which concerns on 4th Embodiment.

[First Embodiment]
Hereinafter, an engine according to a first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a schematic configuration of the main motion system of the engine 1. The engine 1 is a multi-cylinder engine (only one cylinder is shown in FIG. 1) and is mounted on a vehicle (not shown). .

  In the engine 1, a crankshaft 10 is rotatably supported by a main bearing portion 3 of a cylinder block 2 in a crank journal portion 11. A large end portion 21 of a connecting rod 20 is rotatably supported on the crankpin portion 12 of the crankshaft 10. A piston pin 31 for connecting to the piston 30 is rotatably supported on the small end portion 22 of the connecting rod 20. The piston 30 includes a piston ring 32 at a peripheral portion, and is supported by the piston ring 32 on a cylinder inner surface 4a that is an inner surface of the cylinder 4 so as to be able to reciprocate.

  That is, in the main motion system of the engine 1, a first sliding portion 41 is configured by the crank journal portion 11 and the main bearing portion 3, and a second sliding portion 42 is configured by the crank pin portion 12 and the large end portion 21, A third sliding portion 43 is configured by the small end portion 22 and the piston pin 31, and a fourth sliding portion 44 is configured by the piston ring 32 and the cylinder 4.

  Specifically, the first sliding portion 41 is a crank journal outer peripheral surface 11 a that is an outer peripheral surface of the crank journal portion 11 and a inner peripheral surface of the main bearing portion 3, which rotate relatively opposite to each other. A sliding surface is constituted by the main bearing inner peripheral surface 3a.

  The second sliding portion 42 is opposed to each other and relatively rotationally moves. The crankpin outer peripheral surface 12a that is the outer peripheral surface of the crankpin portion 12 and the large end inner peripheral surface that is the inner peripheral surface of the large end portion 21. The sliding surface is constituted by 21a.

  The third sliding portion 43 is opposed to each other and relatively reciprocates and rotates by a small end portion inner peripheral surface 22a which is an inner peripheral surface of the small end portion 22 and a piston pin outer peripheral surface 31a of the piston pin 31. The sliding surface is configured. Note that the rotational reciprocating motion refers to a motion that repeats a motion that rotates relatively to one side and a motion that rotates relatively to the opposite side.

  The fourth sliding portion 44 has a sliding surface constituted by a piston ring outer peripheral surface 32a, which is an outer peripheral surface of the piston ring 32, and a cylinder inner surface 4a, which are opposed to each other and relatively linearly reciprocate. Yes. Note that the linear reciprocating motion refers to a motion that repeats a motion that relatively linearly moves to one side and a motion that relatively linearly moves to the opposite side.

  A low friction layer 40 subjected to a predetermined low friction treatment is formed on the sliding surface of at least one member constituting the first to fourth sliding portions 41 to 44. FIG. 2 shows an enlarged example of the low friction layer 40 formed on the sliding surface. The predetermined low-friction treatment is a surface having minute irregularities coated with a material such as vapor-phase synthesis (CVD) diamond, artificial sapphire, diamond-like carbon (DLC), silicon carbide, titanium carbide, alumina oxide, or alumina. The convex portion 40b is polished smoothly so that the concave portion 40a remains, whereby the low friction layer 40 is formed on the sliding surface.

  The recess 40a is preferably 3 to 10 μm deep, and the protrusion 40b is preferably polished so that the surface roughness Ra of the polished top surface is 0.1 μm or less. According to this low friction layer, when the relative speed U between the two members is equal to or higher than a predetermined speed U0, a dynamic pressure is generated in the recess 40a, and one member with respect to the other member is generated by the dynamic pressure. The levitation effect of levitation is obtained.

As shown in FIG. 1, in the present embodiment shows a low friction layer 40 by cross-hatching, the low friction layer 40 ₁ is formed in the main bearing inner circumferential surface 3a in the first sliding portion 41, the second in the sliding portion 42 is a low friction layer 40 ₂ is formed in the large end peripheral surface 21a, in the third sliding portion 43 a low friction layer 40 ₃ is formed on the piston pin outer peripheral surface 31a, fourth sliding portion It is low-friction layer 40 ₄ formed on the inner surface of the cylinder 4a in 44.

  That is, in the first sliding portion 41, when the relative speed between the crank journal outer peripheral surface 11a and the main bearing inner peripheral surface 3a is equal to or higher than a predetermined speed, the crank journal outer peripheral surface 11a becomes the main bearing inner peripheral surface 3a. On the other hand, it is in a levitation state that is non-contact. At this time, a first air layer 41a made of an air layer is formed between the outer peripheral surface 11a of the crank journal and the inner peripheral surface 3a of the main bearing.

  Similarly, in the second to fourth sliding portions 42 to 44, when the relative speed between both members constituting the sliding portion is equal to or higher than a predetermined speed, one member is not in contact with the other member. It becomes a floating state. That is, in the second sliding portion 42, a second air layer 42a composed of an air layer is formed between the crankpin outer peripheral surface 12a and the large end inner peripheral surface 21a. A third gas layer 43a made of a gas layer is formed between the peripheral surface 22a and the piston pin outer peripheral surface 31a. On the other hand, in the fourth sliding portion 44, the piston ring 32 is biased to the cylinder inner surface 4a by the ring tension, so that it does not float.

  As a result, the frictional resistance in the first to fourth sliding portions 41 to 44 is greatly reduced, and in this embodiment, lubrication with the lubricating oil is unnecessary. In addition, in this specification, in addition to the case where one member is in contact with the other member, the concept of sliding includes a floating state in which one member is not in contact with the other member. To do.

  In the present embodiment, the predetermined speed U0 is realized when the rotational speed NE of the engine 1 is equal to or higher than the first speed V1. For example, in the present embodiment, the first speed V1 of the engine 1 is 200 rpm, which is lower than the idle speed (for example, 600 rpm). That is, since the first speed V1 is lower than the normal rotation range of the engine, after the engine 1 is started, a levitation effect is always obtained in each of the sliding portions 41 to 44. On the other hand, when the engine speed NE is lower than the first speed V1 during the stop operation or engine start operation of the engine 1, the levitation effect is weakened.

A heat insulating layer 45 is formed on the surface of each member constituting the combustion chamber of the engine 1. Specifically, the top surface 30b of the piston 30 constituting the bottom surface of the combustion chamber, the lower surface 8a of the cylinder head 8 constituting the top surface of the combustion chamber, the valve head surface 9a of the intake / exhaust valve 9, and the cylinder inner surface 4a. And the heat insulation layer 45 is formed. In the cylinder inner surface 4a, which is a two-layer structure of a low friction layer 40 ₄ and the heat insulating layer 45, the low friction layer 40 ₄ is formed on the surface side of facing the piston 30, the radially outer (proximal) A heat insulating layer 45 is formed on the surface.

  Various heat-insulating layers are known as the heat-insulating layer 45. For example, it is preferable to include inorganic oxide particles such as zirconia, silica, or alumina, and to use hollow particles made of the inorganic oxide particles. Can do. Specifically, ceramic hollow particles such as alumina bubbles, fly ash balloons, shirasu balloons, silica balloons, airgel balloons, and other inorganic hollow particles can be used as the hollow particles. Each material and particle size are as shown in Table 1.

For example, the chemical composition of the fly _{ash, SiO 2; 40.1~74.4%, Al} 2 O 3; 15.7~35.2%, Fe 2 O 3; 1.4~17.5%, MgO ; 0.2-7.4%
, CaO; 0.3 to 10.1% (the above is mass%). The chemical composition of Shirasu Balloon is
_{SiO 2; 75~77%, Al 2} O 3; 12~14%, Fe 2 O 3; 1~2%, Na 2 O
3-4%, K ₂ O; 2-4%, IgLoss; 2-5% (the above is mass%).

  By providing the heat insulating layer 45 on the wall surface of the combustion chamber, the cooling loss from the combustion chamber to the outside of the combustion chamber is reduced. As a result, the temperature of the combustion chamber increases and the foreign matter adhering to the wall surface of the combustion chamber is combusted. . Therefore, the foreign matter adhering to the piston ring 32 or the cylinder inner surface 4a facing the combustion chamber is removed. Therefore, the surface properties of the piston ring outer peripheral surface 32a and the cylinder inner surface 4a can be maintained in a state where the low friction treatment is performed, and an increase in the frictional resistance in the fourth sliding portion 44 can be suppressed.

  Accordingly, the deposit removing means of the present invention is composed of the heat insulating layer 45, and foreign matter adhering to the sliding surface is removed by the deposit removing means, so that the surface property of the sliding surface is subjected to low friction treatment. Maintaining the state can suppress an increase in frictional resistance. Therefore, the levitation effect of levitation of one member relative to the other member can be maintained.

  Here, a modification of the present embodiment will be described with reference to FIGS. 3 and 4 show the combustion chamber of FIG. 1 in an enlarged manner.

As a modification of the present embodiment, as shown in FIG. 3, a heat insulating layer 45 is formed on the combustion chamber side from the piston ring 32 located at the top dead center on the cylinder inner surface 4a, and a low friction layer 40 is formed on the anti-combustion chamber side. ₄ may be formed.

Further, as another modification of the present embodiment, as shown in FIG. 4, the cylinder inner face 4a, it may be formed a low friction layer 40 ₄ which acts also as a heat insulating layer 45. The low friction layer 40 _4, for example, alumina, by spraying zirconia oxide on the inner surface of the cylinder 4a, is obtained by grinding as described above the solution morphism film.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The engine 200 according to the second embodiment includes a combustion chamber temperature raising unit 210 as a deposit removing unit. The combustion chamber temperature raising means 210 will be described with reference to FIG. FIG. 5 is a cross-sectional view similar to FIG.

  As shown in FIG. 5, the engine 200 is formed with a low friction layer 40 on each sliding surface of the main motion system, similarly to the engine 1 according to the first embodiment. The engine 200 includes combustion chamber temperature raising means 210. The combustion chamber temperature raising means 210 is a thermal reactor provided in the cylinder head 8 and generates heat when energized to raise the temperature of the combustion chamber via the cylinder head 8. Combustion chamber temperature raising means 210 is controlled by a control device (not shown) so as to operate every predetermined period.

  That is, according to this embodiment, the temperature of the combustion chamber is increased by the combustion chamber temperature raising means 210 that operates every predetermined period. As a result, the foreign matter adhering to the wall surface of the combustion chamber is burned and removed every predetermined period. Is done. Accordingly, foreign matter adhering to the piston ring 32 or the cylinder inner surface 4a facing the combustion chamber is removed, so that an increase in frictional resistance can be suppressed by maintaining the surface properties of the sliding surface in a state subjected to the low friction treatment. .

  In addition to raising the temperature of the combustion chamber via the cylinder head 8, as the combustion chamber temperature raising means 210, for example, a glow plug may be arranged so as to face the heater in the combustion chamber.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. The engine 300 according to the third embodiment includes an air supply unit 320 as an adhering matter suppressing unit. The air supply means 320 will be described with reference to FIG. FIG. 6 is a cross-sectional view similar to FIG. 1, showing a schematic configuration of the main motion system of engine 300. As shown in FIG. 6, in the engine 300, the low friction layer 40 is formed in each sliding portion, as in the first embodiment.

  The engine 300 includes an air pump 5, and air is supplied from the air pump 5 to the sliding surfaces of the sliding portions 41 to 44. The cylinder block 2 includes an annular main bearing inner circumferential groove 3b formed in the main bearing inner circumferential surface 3a, and a first air passage 13 communicating the main bearing inner circumferential groove 3b and the air supply pipe 5a from the air pump 5. And.

  The crankshaft 10 includes a second air passage 23. The second air passage 23 has an opening 23a on one end side opened to the crank journal outer peripheral surface 11a, and an opening 23b on the other end side opened to the crank pin outer peripheral surface 12a.

  The connecting rod 20 includes an annular large end inner circumferential groove 21 b formed in the large end inner circumferential surface 21 a and a third air passage 33. The third air passage 33 has an opening 33a opened in the large end inner circumferential groove 21b and an opening 33b opened in the small end inner circumferential surface 22a.

  With the above configuration, the air discharged from the air pump 5 is first supplied to the main bearing inner peripheral groove 3b through the air supply pipe 5a and the first air passage 13, and then from the main bearing inner peripheral groove 3b to the first slide. It is supplied to the sliding surfaces 11a and 3a of the moving part 41. FIG. 7 is a cross-sectional view of the first sliding portion 41 taken along the line VII-VII in FIG. 6. Since the main bearing inner circumferential groove 3b is formed in an annular shape, the opening 23a of the second air passage 23 is Regardless of the rotation of the crankshaft 10, the main bearing inner circumferential groove 3 b always faces the air, and air is always supplied efficiently from the first air passage 13 to the second air passage 23.

  As shown in FIG. 6, at this time, a part of the air supplied to the sliding surfaces 11a and 3a of the first sliding portion 41 is not supplied to the second air passage 23, and the main bearing inner peripheral surface 3a. And the outer peripheral surface 11a of the crank journal are ejected to the outside of the sliding surface through the first air layer 41a.

  The air supplied to the second air passage 23 is supplied to the sliding surfaces 12 a and 21 a of the second sliding portion 42. Since the large end inner circumferential groove 21b is formed in an annular shape, the opening 23a of the second air passage 23 always faces the large end inner circumferential groove 21b regardless of the rotation of the crankshaft 10, so that the second air Air is always efficiently supplied from the passage 23 to the third air passage 33 through the large end inner circumferential groove 21b.

  At this time, a part of the air supplied to the sliding surfaces 12a and 21a of the second sliding portion 42 is not supplied to the third air passage 33, and the large end inner peripheral surface 21a and the crankpin outer peripheral surface 12a Is ejected to the outside of the sliding surface through the gap (second gas layer 42a).

  The air supplied to the third air passage 33 is supplied to the sliding surfaces 22a, 31a of the third sliding portion 43, and a gap (third) between the small end inner peripheral surface 22a and the piston pin outer peripheral surface 31a. Through the air layer 43a), it is ejected to the outside of the sliding surface, and part of it passes between the piston pin hole 30a and the piston pin outer peripheral surface 31a and is ejected to the cylinder inner surface 4a. The air released to the cylinder inner surface 4a is supplied to the piston ring outer peripheral surface 32a along the cylinder inner surface 4a.

  That is, at least the air supply pipe 5a, the first air passage 13, the main bearing inner peripheral groove 3b, the first air layer 41a, the second air passage 23, the second air layer 42a, and the inner end of the large end portion. The groove 21b, the third air passage 33, and the third air layer 43a constitute an air supply path 310 from the air pump 5 to each sliding surface. The air supply path 310 is provided corresponding to each cylinder. For example, when the engine 1 is a four-cylinder engine as shown in FIG. 8, the air pump 5 corresponds to the first to fourth cylinders. Are provided with first to fourth air supply paths 311 to 314 respectively extending from the first to fourth sliding portions 41 to 44 of each cylinder. The air supply path 320 and the air pump 5 constitute the air supply means 320 of the present invention.

  That is, by operating the air supply means 320, air can be ejected from the sliding surfaces 11a and 3a to the outside in the first sliding portion 41, and the sliding surfaces 12a and 3a in the second sliding portion 42. Air can be ejected from 21a to the outside, and in the third sliding portion 43, air can be ejected from the sliding surfaces 22a and 31a to the outside or the cylinder inner surface 4a.

  Thus, by operating the air supply means 320 every predetermined period, foreign matter adhering to the sliding surface is removed, so that accumulation of foreign matter on the sliding surface is suppressed. Therefore, since the increase in the frictional resistance on the sliding surface is suppressed, the levitation effect of levitation of one member relative to the other member can be maintained.

  In addition, when the air supply means 320 is operated, the air bearings can be configured by forming the first to third air layers 41a to 43a in the sliding portions 41 to 43, so that the relative speed of the sliding surface is predetermined. Even when the speed is lower than the above, it is easy to keep the sliding portions 41 to 43 in a floating state, and the frictional resistance on the sliding surface can be greatly reduced, and the sliding surfaces come into contact with each other and slide. Is suppressed.

[Fourth Embodiment]
Next, an engine 400 according to a fourth embodiment of the present invention will be described. The engine 400 may be either the engine 200 described in the second embodiment or the engine 300 described in the third embodiment. However, each of the above points is provided with a control device 410 that activates the combustion chamber temperature raising means 210 or the air supply means 320 as the deposit removing means when detecting or estimating the accumulation of foreign matter exceeding a predetermined amount. This is different from the embodiment.

  FIG. 9 shows a schematic configuration of a control system of engine 400. As shown in FIG. 9, in the control system of engine 400, control device 410 receives input signals from various sensors 70, and combustion chamber temperature raising means 210 (or air supply means 320) serves as a deposit removal means. Is to control.

  Examples of the various sensors 70 include an engine rotation sensor 71, a torque sensor 72, an intake pressure sensor 75, and an airflow sensor 76. The engine rotation sensor 71 detects the rotation of the crankshaft 10. Torque sensor 72 detects the actual torque of engine 400. The intake pressure sensor 75 detects an intake pressure in an intake manifold (not shown). The airflow sensor 76 detects the amount of intake air in the intake pipe (not shown).

  Control device 410 receives a signal from engine rotation sensor 71 and determines the rotation speed of engine 400.

  Further, the control device 410 calculates the amount of air sucked into the cylinder based on the engine rotation speed and the signal from the intake pressure sensor 75 and / or the airflow sensor 76, and this air amount and the predetermined amount are calculated. The target torque realized by the fuel injection amount determined by the air-fuel ratio is calculated.

  Further, the control device 410 receives a signal from the torque sensor 72, calculates a difference Z between the actual torque and the target torque, and calculates a difference integrated value Z1 obtained by integrating the difference Z.

  Further, the control device 410 determines whether or not the difference integrated value Z1 exceeds a predetermined threshold value Z0, and if it is determined that the difference integrated value Z1 exceeds the predetermined threshold value Z0, the combustion chamber temperature increasing means 210 (or the deposit removal means) (or The air supply means 320) is controlled to operate for a predetermined time. Since the accumulated difference value Z1 and the accumulated amount of foreign matter in the combustion chamber have a correlation, a predetermined amount of accumulated difference value is determined based on the accumulated amount of foreign matter so as not to increase the sliding resistance on the sliding surface. A threshold value Z0 is set as Z1.

  Next, the operation of the engine system 400 when operating the deposit removing means will be described with reference to the flowchart of FIG. 10 and the time chart of FIG.

  As shown in FIG. 10, in step S <b> 401, the control device 410 reads signals from various sensors 70.

  In step S <b> 402, control device 410 calculates a target torque based on signals from engine rotation sensor 71, intake pressure sensor 75 and / or airflow sensor 76.

  In step S403, the control device 410 calculates a difference Z between the actual torque measured by the torque sensor 72 and the target torque calculated in step S402, and is burned in the combustion chamber based on the difference Z. The amount of foreign matter such as unburned gas that has not been generated is calculated, and the difference Z is integrated to calculate the difference integrated value Z1.

  In step S404, control device 410 determines whether or not difference integrated value Z1 has exceeded a predetermined threshold value Z0.

  When it is determined that the difference integrated value Z1 has exceeded the predetermined threshold value Z0, in step S405, the control device 410 operates the combustion chamber temperature raising means 210 (air supply means 320) as the deposit removal means.

  In step S406, control device 410 determines whether or not a predetermined time has elapsed.

  When it is determined that the predetermined time has elapsed, in step S407, the control device 410 stops the combustion chamber temperature raising means 210 (air supply means 320) as the deposit removal means.

  That is, as shown in FIG. 11, the operation is started at time t0, the foreign matter adhesion amount Z is integrated from the difference between the target torque and the actual torque during that time, and this difference integrated value Z1 becomes the threshold value Z0 at time t2. When exceeded, the combustion chamber temperature raising means 210 as the deposit removing means is operated for a predetermined time until time t3. Thereby, the foreign matter adhering to the combustion chamber is burned and removed. Then, the difference integrated value Z1 is reset to 0 again, and the difference is integrated again according to the engine operating condition thereafter.

  Therefore, according to the present embodiment, the fuel that has not been burned is calculated from the difference Z between the target torque and the actual torque, and this difference is integrated to calculate the difference integrated value, thereby correlating with this. The amount of foreign matter attached is detected. Then, when the integrated value Z1 exceeds a predetermined threshold value Z0, it is detected that a foreign matter exceeding a predetermined amount has adhered to the sliding surface. At this time, the foreign matter removing means is operated to remove the foreign matter attached to the sliding surface. It can be removed more effectively. Therefore, the accumulation of foreign matter on the sliding surface can be more efficiently suppressed.

  In addition, the amount of foreign matter adhering to the combustion chamber can be accurately detected based on the difference between the target torque and the actual torque.

  Further, the control device 410 may estimate the amount of adhering foreign matter from the transition of the engine speed and the transition of the fuel injection amount.

  In the above embodiment, the case where the friction reducing process is applied to the sliding portion of the main motion system of the engine has been described as an example. However, the present invention is applied to various sliding portions such as a valve train of the engine and a transmission. can do. In each of the above embodiments, the case where no lubrication is used has been described as an example, but lubrication may be used in combination.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made without departing from the spirit and scope of the present invention described in the claims.

  As described above, according to the present invention, when a friction reducing method by levitation is used for an engine, levitation is performed by removing foreign matter adhering to the sliding surface and levitation of one member relative to the other member. Since the effect can be sustained, it may be suitably used in this type of manufacturing technology field.

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder block 3 Main bearing part 4 Cylinder 5 Air pump 10 Crankshaft 20 Connecting rod 30 Piston 31 Piston pin 32 Piston ring 40 Low friction layer 41 1st sliding part 42 2nd sliding part 43 3rd sliding part 44 Fourth sliding portion 45 Heat insulation layer 70 Sensor 71 Engine rotation sensor 72 Torque sensor 75 Intake pressure sensor 76 Air flow sensor 200 Engine 210 Combustion chamber temperature raising means 300 Engine 320 Air supply means 400 Engine 410 Controller

Claims (6)

A first member and a second member that moves relative to the first member, and a relative speed of both members is predetermined on a sliding surface of at least one of the first member and the second member. An engine having a low friction layer that has been subjected to a friction reduction process that floats one of the members relative to the other member at the time described above,
The friction reduction process is a process for levitating without requiring lubricating oil,
The low friction layer is a plurality of protrusions having a top surface roughness Ra of 0.1 μm or less, and each of the plurality of protrusions formed at the same height is positioned around the protrusions. And a plurality of recesses having a depth of 3 to 10 μm, and a predetermined coating layer,
An engine comprising an adhering matter removing means for removing foreign matter adhering to the sliding surface. Wherein the first member is a piston ring provided on the piston, the second member is a cylinder, the deposit removal means, Ri insulation layer der provided around the low-friction layer ,
The heat insulation layer is formed on the combustion chamber side from the piston ring in a state where the piston is located at the top dead center on the inner surface of the cylinder, and the low friction layer is formed on the anti-combustion chamber side from the piston ring. that is,
The engine according to claim 1. The first member is a piston ring provided on a piston, the second member is a cylinder, and the deposit removing means acts as a heat insulating layer on the inner surface of the cylinder. Is,
The engine according to claim 1 . The deposit removal means jetting air to the outside of the sliding surface from the sliding surface, Ri air supply means der,
The air supply means includes
An air pump,
An air supply path for communicating the air pump and a plurality of sliding surfaces of the engine to supply air from the air pump to the plurality of sliding surfaces;
The that has,
The engine according to claim 1 . The plurality of sliding surfaces are
A first sliding portion configured between the outer peripheral surface of the crank journal and the inner peripheral surface of the main bearing;
A second sliding portion configured between the outer peripheral surface of the crankpin and the inner peripheral surface of the connecting rod large end portion;
A third sliding portion configured between the inner peripheral surface of the small end of the connecting rod and the outer peripheral surface of the piston pin;
A fourth sliding portion configured between the piston ring and the inner surface of the cylinder;
Provided in
The air supply path is
A first air passage communicating the air pump and the inner peripheral surface of the main bearing;
A second air passage formed in the crankshaft, which communicates the outer peripheral surface of the crank journal and the outer peripheral surface of the crank pin;
A third air passage that is formed in the connecting rod and communicates with the connecting rod large end inner peripheral surface and the connecting rod small end inner peripheral surface;
Have
The air discharged from the air pump is jetted from the piston to the inner surface of the cylinder via the first air passage, the second air passage, and the third air passage.
The engine according to claim 4 . Based on a difference integrated value obtained by integrating the difference between the target torque and the actual torque, when it is detected or estimated that a foreign substance exceeding a predetermined amount has adhered to the sliding surface, the attached matter removing means operates.
The engine according to claim 4 or 5 .

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