JP4715602B2 - Lubricating device for internal combustion engine - Google Patents

Description

  The present invention relates to a lubricating device for an internal combustion engine, and more particularly to a lubricating device for an internal combustion engine that circulates lubricating oil mixed with microbubbles.

  In general, an internal combustion engine includes stationary parts such as an oil pan, a cylinder block, and a cylinder head, and moving parts such as a piston, a connecting rod, a crankshaft, and intake and exhaust valves. When the internal combustion engine is driven, the stationary part and the moving part or the moving parts move such as rotating and sliding. Therefore, friction is generated in the lubrication part between the stationary part and the moving part of the internal combustion engine or between the moving part and the moving part, and the frictional resistance is lost to the driving force (output torque) output from the internal combustion engine. It becomes. Of all the losses to the driving force output from the internal combustion engine, the ratio of losses due to this friction is high. For example, the friction when the piston reciprocates with respect to the cylinder block, that is, the frictional resistance between the cylinder liner and the piston ring, is the largest loss due to this friction.

  In general, in a conventional internal combustion engine, liquid lubrication is performed by supplying lubricating oil to a lubricating portion of the internal combustion engine in order to reduce loss due to friction. Here, there is a demand for improvement in fuel consumption and higher output of the internal combustion engine, and further improvement in thermal efficiency of the internal combustion engine is desired. Therefore, even if liquid lubrication is performed, the friction of the lubrication part is still large, and further reduction of the loss due to friction is desired.

  By the way, conventionally, as shown in Patent Document 1, a technique for reducing the apparent viscosity of oil has been proposed. Patent Document 1 discloses an engine cooling device that cools an engine by circulating oil through an oil jacket formed in a cylinder block of an engine that is an internal combustion engine. A bubble generator is disposed at a predetermined position of the oil jacket, and fine bubbles are mixed into the oil from the bubble generator to reduce the apparent viscosity of the oil.

  Here, in this patent document 1, air is ejected from one side of a very small number of small holes formed on the surface of the bubble generator or a very fine mesh toward the other side. Generates fine bubbles. The extremely fine bubbles are assumed to have a diameter of 1 mm or less. However, the bubbles generated by the small holes or the nets are small and easily visible, for example, bubbles having a diameter of about 0.2 mm. If it is a bubble of said diameter, there exists a possibility that bubbles may merge and absorb and it may become a big bubble. Therefore, when oil is circulated, the large air bubbles are sucked into the pump that sucks and discharges the oil, which may reduce the discharge capacity of the pump.

Japanese Utility Model Publication No. 63-78122

  Accordingly, the present invention has been made in view of the above, and an object of the present invention is to provide a lubricating device for an internal combustion engine that can reduce loss due to friction with respect to the driving force output from the internal combustion engine. is there.

In order to solve the above-described problems and achieve the object, the present invention provides a microbubble generating means for generating microbubbles in a lubricating device for an internal combustion engine that circulates lubricating oil in the internal combustion engine and lubricates the internal combustion engine. And bubble generation control means for controlling the generation of microbubbles by the microbubble generation means, and an oil level sensor for detecting the oil level of a lubricating oil storage chamber for storing lubricating oil circulated through the internal combustion engine. The bubble generation control means includes any one of an engine speed, a load or an oil temperature of the lubricating oil of the internal combustion engine, and an oil level height of the lubricating oil storage chamber detected before and after mixing the microbubbles. based on the control the bubble mixing amount with respect to the lubricating oil by the microbubble generator, incorporating the generated microbubbles in the lubricating oil And wherein the door.

Further, according to the present invention, in a lubricating device for an internal combustion engine that circulates lubricating oil in the internal combustion engine and lubricates the internal combustion engine, microbubble generation means for generating microbubbles, and generation of microbubbles by the microbubble generation means A bubble generation control means for controlling light, a light source for irradiating light to the lubricating oil circulating in the internal combustion engine, and an optical sensor for detecting the intensity of transmitted light of the lubricating oil, the bubble generation control means comprising the internal combustion engine Based on any one of the engine speed, load, or oil temperature of the lubricating oil, and the detected intensity of transmitted light of the lubricating oil, the amount of bubbles mixed into the lubricating oil by the microbubble generating means is determined. Controlling and mixing the generated microbubbles into the lubricating oil.

According to these inventions, the microbubble generating means mixes microbubbles, which are extremely fine bubbles, into the lubricating oil such that it is difficult to visually recognize the lubricating oil circulating in the internal combustion engine. That is, the lubricating oil mixed with microbubbles is supplied to the lubrication part between the stationary part and the moving part of the internal combustion engine and between the moving part and the moving part. Therefore, it is considered that the disturbance of the boundary layer between the lubricating portion and the lubricating oil is suppressed by the microbubbles. Moreover, it is thought that the density of lubricating oil falls by mixing microbubbles, and the contact area of the liquid part except the microbubble of lubricating oil and a lubrication part falls. As a result, the frictional resistance can be reduced more than the frictional resistance of the lubrication portion when liquid lubrication is performed, and loss due to friction with respect to the driving force output from the internal combustion engine can be reduced.

  Further, the microbubbles mixed in the lubricating oil disappear while being dissolved in the lubricating oil, and the bubbles are difficult to coalesce and absorb, so that the microbubbles can be prevented from collecting and forming large bubbles. Therefore, even if an oil pump that sucks and discharges this oil is used to circulate the lubricating oil mixed with microbubbles to the internal combustion engine, it is possible to suppress a decrease in the discharge capacity of the oil pump.

In addition, the bubble generation control means is a lubricant oil generated by the microbubble generation means according to the operating state of the internal combustion engine, for example, a decrease in the oil temperature of the lubricating oil, a decrease in the load on the internal combustion engine, and an increase in the engine speed of the internal combustion engine. Increase the amount of bubbles mixed in against. In other words, the bubble generation control means responds to the operating state of the internal combustion engine that easily causes the oil film to be cut off in the lubricating portion, for example, an increase in the oil temperature of the lubricating oil, an increase in the load of the internal combustion engine, or a decrease in the engine speed of the internal combustion engine The amount of bubbles mixed in the lubricating oil by the microbubble generating means is reduced. Therefore, the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, loss due to friction with respect to the driving force output from the internal combustion engine can be reduced, and the lubrication part in which the mixed lubrication is performed can be reduced. Oil film breakage can be suppressed, and a decrease in seizure resistance between members constituting the lubrication portion can be suppressed.

Moreover, the bubble mixing amount with respect to the lubricating oil of microbubbles can be detected based on the detected oil surface height of the lubricating oil storage chamber or the detected transmitted light intensity of the lubricating oil. Therefore, for example, when the detected bubble mixing amount is equal to or larger than the target bubble mixing amount, the generation of microbubbles is stopped. Therefore, the bubble mixing amount can be maintained at an appropriate value, so that the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, and the loss due to friction with respect to the driving force output from the internal combustion engine is reduced. In addition, it is possible to suppress the oil film breakage of the lubricated portion where the mixed lubrication is performed, and it is possible to suppress a decrease in seizure resistance between members constituting the lubricated portion.

  According to the present invention, in the lubricating device for an internal combustion engine, the microbubble generating means includes a gas introducing device having an introducing portion for forming bubbles in the circulating lubricating oil, and bubbles formed in the introducing portion. And an ultrasonic generator that generates ultrasonic waves to be vibrated.

  According to this invention, the bubbles in the lubricating oil formed in the introduction part of the gas introduction device are vibrated by the ultrasonic waves generated by the ultrasonic generator. Therefore, a surface wave is generated on the surface of the bubble, and the microbubble is separated from the wave front and mixed into the lubricating oil. Thereby, microbubbles can be stably mixed into the lubricating oil.

  According to the present invention, in the lubricating device for an internal combustion engine, the gas introducing device introduces bubbles into the lubricating oil sucked by an oil pump that circulates the lubricating oil to the internal combustion engine.

  According to the present invention, in the lubricating device for an internal combustion engine, the microbubble generating means is a gas introducing device that introduces bubbles into the lubricating oil sucked by an oil pump that circulates the lubricating oil to the internal combustion engine. It is characterized by.

  According to the present invention, bubbles in the lubricating oil formed in the introduction portion of the gas introducing device or bubbles introduced into the lubricating oil by the microbubble generator are sucked into the oil pump. The bubbles sucked by the oil pump are sheared by members that move relative to suck and discharge the lubricating oil among the members constituting the oil pump. That is, microbubbles are generated by this shearing force, and the generated microbubbles are mixed in the lubricating oil discharged from the oil pump. Thereby, microbubbles can be stably mixed into the lubricating oil.

According to the present invention, in the lubricating device for an internal combustion engine, the generated microbubbles are mixed into the lubricating oil in a lubricating oil storage chamber for storing lubricating oil circulated through the internal combustion engine .

  According to the present invention, microbubbles are mixed in the lubricating oil stored in the lubricating oil storage chamber, but the microbubbles do not disappear and maintain the state of being mixed in the lubricating oil for a long time. Therefore, even if many microbubbles are mixed in the lubricating oil stored in the lubricating oil storage chamber in a short time, this lubricating oil maintains a state where the microbubbles are mixed, and between the stationary part and the moving part. Further, it is supplied to a lubrication part between the moving parts and the moving parts, and the loss due to friction with respect to the driving force output from the internal combustion engine is reduced. Thereby, by mixing microbubbles into the lubricating oil stored in the lubricating oil storage chamber, the lubricating oil is changed from a state where no microbubbles are mixed into a state where many microbubbles are mixed in a short time. Therefore, loss due to friction with respect to the driving force output from the internal combustion engine can be reduced in a short time.

  According to the present invention, in the lubricating device for an internal combustion engine, a mixing-side circulation path for circulating the lubricating oil mixed with the microbubbles and a non-mixing-side circulation path for supplying the lubricating oil not mixed with the microbubbles It is characterized by providing.

  According to the present invention, two types of lubricating oil, that is, lubricating oil mixed with microbubbles and lubricating oil not mixed with microbubbles can be circulated in the internal combustion engine. Accordingly, the lubricating oil mixed with microbubbles can reduce the frictional resistance more than the frictional resistance of the lubrication part when liquid lubrication is performed, and the loss due to friction with respect to the driving force output from the internal combustion engine can be reduced. . In addition, the lubricating oil in which microbubbles are not mixed can suppress oil film breakage in the lubricated portion where mixed lubrication consisting of fluid lubrication and boundary lubrication is performed, and seizure resistance between members constituting the lubricated portion Can be suppressed.

  According to the present invention, in the lubricating device for an internal combustion engine, the bubble generation control means is estimated from an oil temperature of the lubricating oil and at least one of the pressure of the lubricating oil and the engine speed of the internal combustion engine. Based on the viscosity of the lubricating oil, the amount of bubbles mixed into the lubricating oil by the microbubble generating means is controlled.

According to the present invention, the bubble generation controller means, For example the operating state of the internal combustion engine, in response to an increase in viscosity of Jun Namerayu, increasing the bubble mixing amount with respect to the lubricating oil by the microbubble generator. In other words, the bubble generation controller means, lubrication operation state of the prone engine oil film breakage, for example, with a decrease in the viscosity of Jun Namerayu, reducing the bubble mixing amount with respect to the lubricating oil by the microbubble generator. Therefore, the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, loss due to friction with respect to the driving force output from the internal combustion engine can be reduced, and the lubrication part in which the mixed lubrication is performed can be reduced. Oil film breakage can be suppressed, and a decrease in seizure resistance between members constituting the lubrication portion can be suppressed.

  The lubrication apparatus for an internal combustion engine according to the present invention has the effect of reducing loss due to friction with respect to the driving force of the internal combustion engine because microbubbles are mixed into the lubricating oil circulating through the internal combustion engine.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following Example. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or that are substantially the same. The internal combustion engine lubrication device described below is a device that circulates lubricating oil to an engine body such as a gasoline engine, a diesel engine, or an LPG engine mounted on a vehicle such as a passenger car or a truck.

FIG. 1 is a diagram illustrating a configuration example of a lubricating device for an internal combustion engine according to a first reference example . An internal combustion engine lubrication device 1-1 according to the present invention includes an oil pan 2, an oil supply path 3, a microbubble generator 4, and a control device 5.

  The oil pan 2 is a lubricating oil storage chamber that stores lubricating oil (hereinafter simply referred to as “oil”) for lubricating an internal combustion engine (not shown). The oil pan 2 is disposed, for example, at a lower portion of a crankcase of an internal combustion engine (not shown), and is supplied to a lubrication portion between a stationary part and a moving part of the internal combustion engine (not shown) and between the moving part and the moving part. This is where the oil returns and is stored.

  The oil supply path 3 supplies oil stored in the oil pan 2 to a lubrication part between a stationary part and a moving part (not shown) of the internal combustion engine and between the moving part and the moving part. The oil supply path 3 includes an oil pump 31 and an oil supply path 32. The oil pump 31 is for pumping oil stored in the oil pan 2 to the lubrication part. The oil pump 31 is operated, for example, by rotating a crankshaft to which a driving force of an internal combustion engine (not shown) is transmitted, that is, an operating force of the internal combustion engine. The oil supply passage 32 communicates the oil pan 2 and the lubrication part via the oil pump 31. Here, as each lubrication portion, between the cylinder block and the piston, between the cylinder head and the intake / exhaust valve, between the cylinder head and the camshaft, between the piston and the connecting rod, and between the connecting rod and the crankshaft. , Between the intake and exhaust valves and the cam.

  Reference numeral 33 denotes a bubble mixing amount sensor which is a bubble mixing amount detection unit that detects the bubble mixing amount of the microbubbles M mixed in the oil passing through the oil supply path 3 and outputs the detected amount to the control device 5. The bubble mixing amount sensor 33 mixes the bubble mixing amount into the oil based on, for example, the flow rate, flow rate, pressure difference, etc. of the oil when passing through the oil supply passage 32 or the change in the work amount of the oil pump 31. The amount of mixed bubbles of the microbubbles M detected is detected. This is because the oil flow in the oil supply passage 32 increases in the oil mixed with the microbubbles M when the operating conditions of the oil pump 31 are the same, compared with the oil in which the microbubbles M are not mixed. This is because the flow rate increases and the pressure difference decreases. Moreover, it is because the work volume of the oil pump 31 becomes small by these.

  The microbubble generator 4 is a microbubble generator that generates microbubbles M, and includes a mixing tank 41, a bubble pump 42, a gas suction passage 43, an oil suction passage 44, and a bubble discharge passage 45. ing.

  The mixing tank 41 is a tank that mixes a gas such as air introduced through the gas suction passage 43 and a liquid that is oil introduced through the oil suction passage 44. In the mixing tank 41, the oil in the oil pan 2 flows through the oil suction passage 44, and the oil flows out to the oil pan 2 through the bubble discharge passage 45. A bubble generating mechanism 41 a is provided between the mixing tank 41 and the bubble discharge passage 45. The bubble generating mechanism 41a generates microbubbles M from the gas in the mixing tank 41 by shearing force when oil is ejected from the bubble generating mechanism 41a into the bubble discharge passage 45. Here, the microbubble M is not a bubble having a size that is easy to visually recognize, but is an extremely fine bubble that is difficult to visually recognize, and has a diameter of 50 μm, preferably 20 to 30 μm. The microbubbles M are difficult to combine and absorb between bubbles, can float in the liquid for a long time, and disappear while being dissolved in the liquid oil. The size of the bubbles (gas) existing in the mixing tank 41 is larger than that of the microbubbles M, and the size of the bubbles may be combined or absorbed.

  The bubble pump 42 is operated by a drive source 42 a such as a motor, and sucks oil stored in the oil pan 2 through the oil suction passage 44 and discharges it to the mixing tank 41. The bubble pump 42 sucks and discharges oil, for example, when a fin in the casing is rotated by a drive source 42a. The bubble pump 42 is operated by a bubble pump drive signal output from the control device 5.

  The gas suction passage 43 sucks a gas such as air outside the microbubble generator 4 and mixes it with the oil in the oil suction passage 44. The gas suction passage 43 communicates with an oil suction passage 44 between the oil pan 2 and the mixing tank 41. When a negative pressure is generated in the oil suction passage 44, a negative pressure is also generated in the gas suction passage 43. Therefore, for example, gas is introduced from the outside, which is atmospheric pressure, into the oil suction passage 44 through the gas suction passage 43, The oil is mixed into the oil in the oil intake passage 44. Since the gas suction passage 43 is also in communication with the mixing tank 41, a part of the oil mixed with the gas in the mixing tank 41 is returned to the oil suction passage 44 through the gas suction path 43, Gas is mixed again.

  The oil suction passage 44 and the bubble discharge passage 45 are provided with a suction control valve 46 and a discharge control valve 47, respectively. The suction control valve 46 and the discharge control valve 47 are opened and closed based on a control valve opening / closing signal output from the control device 5.

  The control device 5 is bubble generation control means for controlling the generation of microbubbles. The control device 5 receives the bubble mixing amount detected by the bubble mixing amount sensor 33 and controls the microbubble generator 4 based on the bubble mixing amount.

  Specifically, the input / output unit (I / O) 51 that inputs and outputs the input signal and the output signal, the operation and stop of the bubble pump 42, and the determination of the opening and closing valves of the suction control valve 46 and the discharge control valve 47 The processing unit 52 to perform and the storage unit 53 are configured. The processing unit 52 includes a bubble mixing amount acquisition unit 54 and a bubble generation control unit 55. The processing unit 52 includes a memory and a CPU (Central Processing Unit), and loads a program based on the control method for the microbubble generator into the memory and executes the program, thereby controlling the microbubble generator control method. It may be realized. The storage unit 53 is a non-volatile memory such as a flash memory, a non-volatile memory such as a ROM (Read Only Memory), or a volatile memory that can be read and written such as a RAM (Random Access Memory). The memory can be configured by a combination of these. Note that the control device 5 does not need to be configured alone, and an ECU (Engine Control Unit) that controls the operation of the internal combustion engine may have the function of the control device 5.

Next, the operation of the lubrication apparatus 1-1 for the internal combustion engine according to Reference Example 1. In particular, a control method for the microbubble generator will be described. FIG. 2 is a diagram illustrating a control flow of the microbubble generator according to the first reference example . FIG. 3 is a diagram illustrating the relationship between the frictional force and the bubble mixing amount. First, as shown in FIG. 2, the bubble generation control unit 55 of the processing unit 52 of the control device 5 first operates the microbubble generation device 4 (step ST101). Specifically, for example, by outputting a bubble pump drive signal for driving the drive source 42a, the drive source 42a is activated, and the bubble pump 42 is activated. In addition, a control valve opening / closing signal for opening each of the suction control valve 46 and the discharge control valve 47 is output, and the suction control valve 46 and the discharge control valve 47 are opened.

  When the bubble pump 42 is operated with the suction control valve 46 and the discharge control valve 47 opened, the oil stored in the oil pan 2 is sucked into the bubble pump 42 via the oil suction passage 44. . At this time, due to the negative pressure generated in the oil suction passage 44, air as a gas is sucked into the gas suction passage 43, and this air is also sucked into the bubble pump 42 together with the oil. Oil and air sucked into the bubble pump 42 are pressurized by the bubble pump 42 and discharged to the mixing tank 41. The oil and air discharged to the mixing tank 41 are mixed in the mixing tank 41. By operating the bubble pump 42, the pressurized oil and air discharged to the mixing tank 41 flow out into the bubble discharge passage 45 through the bubble generating mechanism 41a in a mixed state. At this time, the bubble generating mechanism 41 a generates microbubbles M from the gas in the mixing tank 41 by shearing force when oil is ejected from the bubble generating mechanism 41 a to the bubble discharge passage 45. Accordingly, the oil and the microbubbles M flow out to the oil pan 2 through the bubble discharge passage 45. That is, the microbubble generator 4 can mix the microbubbles M in the oil stored in the oil pan 2.

  The microbubbles M mixed in the oil do not disappear and maintain the state mixed in the oil for a long time. Therefore, the oil stored in the oil pan 2 is maintained by the oil supply path 3 while maintaining the state in which many microbubbles M are mixed even if many microbubbles M are mixed by the microbubble generator 4. It is supplied to a lubricating part of an internal combustion engine (not shown) and reduces loss due to friction with respect to the driving force output from the internal combustion engine. Thus, by mixing the microbubbles M in the oil stored in the oil pan 2, the oil is changed from a state where the microbubbles M are not mixed to a state where many microbubbles M are mixed in a short time. Therefore, loss due to friction with respect to the driving force output from the internal combustion engine can be reduced in a short time.

  Here, when an internal combustion engine (not shown) is driven and the oil pump 31 is operated, the oil mixed with the microbubbles M is supplied from the oil pan 2 to the lubricating portion of the internal combustion engine via the oil supply passage 32. It is considered that the microbubbles M mixed in the oil supplied to the lubrication part of the internal combustion engine can suppress the disturbance of the boundary layer between the lubrication part and the oil generated in the lubrication part. Moreover, the density of oil falls because the microbubble M is mixed in the oil supplied to the lubrication part of the internal combustion engine. That is, it is considered that the contact area between the liquid portion excluding the oil microbubbles M and the lubricating portion is reduced. Therefore, as shown in FIG. 3, the frictional force of the lubrication part of the internal combustion engine changes according to the amount of oil bubble mixed, and the frictional force of the lubrication part of the internal combustion engine decreases as the oil contains more microbubbles M. . As a result, by performing liquid lubrication of the lubrication part of the internal combustion engine with oil mixed with microbubbles M, the frictional resistance can be reduced more than the frictional resistance of this lubrication part when performing liquid lubrication only with conventional oil. The loss due to friction with respect to the driving force output from the internal combustion engine can be reduced.

  Note that oil supplied to a lubricating portion of an internal combustion engine (not shown) is sucked into the oil pump 31, pressurized by the oil pump 31, and discharged to the oil supply passage 32. At this time, the microbubbles M are mixed in the oil pressurized by the oil pump 31, but the microbubbles M disappear while dissolving in the oil, and the bubbles are difficult to merge and absorb. It is difficult to gather and form large bubbles. Therefore, even if the oil mixed with the microbubbles M is circulated to the internal combustion engine by the oil pump 31, it is possible to suppress a decrease in the discharge capacity of the oil pump 31.

  Next, as shown in FIG. 2, the bubble mixing amount acquisition unit 54 of the processing unit 52 acquires a bubble mixing amount A of oil circulating through an internal combustion engine (not shown) (step ST102). Specifically, the bubble mixing amount A detected by the bubble mixing amount sensor 33 and output to the control device 5 is acquired.

  Next, the bubble generation control unit 55 of the processing unit 52 determines whether or not the bubble mixing amount A of oil circulating through the internal combustion engine (not shown) acquired by the bubble mixing amount acquiring unit 54 is equal to or greater than a predetermined value A1. (Step ST103). As shown in FIG. 3, when the relationship between the oil bubble mixing amount A and the frictional force of the lubrication part is greater than a certain level, the frictional force of the lubrication part is difficult to reduce. This is because the microbubbles M mixed in the oil are considered to be saturated. Here, the predetermined value A1 is an oil bubble mixing amount that makes it difficult to reduce the frictional force of the lubricating portion.

  Next, when the bubble generation control unit 55 of the processing unit 52 determines that the bubble mixing amount A of oil circulating through an internal combustion engine (not shown) is equal to or greater than the predetermined value A1, the microbubble generation device 4 is stopped (step ST104). Specifically, for example, the output of the bubble pump drive signal for driving the drive source 42a is stopped, or the drive source 42a is stopped by outputting the bubble pump drive stop signal for stopping the drive source 42a. The bubble pump 42 is stopped. Further, the suction control valve 46 and the discharge control valve 47 are each output with a control valve opening / closing signal for closing the valve, or by stopping the output of the control valve opening / closing signal for opening each valve. 46 and the discharge control valve 47 are closed. The bubble generation control unit 55 of the processing unit 52 determines that the bubble mixing amount A of the oil circulating through the internal combustion engine is greater than or equal to a predetermined value A1, and the bubble mixing amount acquisition unit 54 circulates through the internal combustion engine. The acquisition of the mixing amount A is repeated.

  Therefore, the bubble mixing amount A detected by the bubble mixing amount sensor 33 and acquired by the bubble mixing amount acquisition unit 54 is not less than the predetermined value A1, that is, the microbubbles M are sufficiently mixed in the lubricating oil circulating in the internal combustion engine. In this case, the microbubble generator 4 is stopped and the generation of the microbubble M is stopped. Therefore, compared with the case where the microbubble generator 4 always generates the microbubble M, the driving force for generating the microbubble M can be suppressed. Thereby, when the driving force output from the internal combustion engine which is not illustrated in order to generate the microbubble M is utilized, the loss with respect to the driving force of this internal combustion engine can be reduced.

In the reference example 1 , the microbubble generator 4 once mixes oil and gas in the mixing tank 41, but the microbubble generator in the present invention is not limited to this. For example, the oil suction passage 44 may be directly connected to the bubble generation mechanism 41 a without providing the mixing tank 41, and the oil stored in the oil pan 2 may be directly supplied to the bubble generation mechanism 41 a by the bubble pump 42. At this time, the gas suction passage 43 is directly connected to the bubble generation mechanism 41a so that the gas is sucked into the bubble generation mechanism 41a by the negative pressure generated when oil is ejected from the bubble generation mechanism 41a to the bubble discharge passage 45. Anyway.

It will now be described lubricating device 1-2 for an internal combustion engine according to Reference Example 2. FIG. 4 is a diagram illustrating a configuration example of a lubricating device for an internal combustion engine according to a second reference example . FIG. 5A is a diagram illustrating a configuration example of a microbubble generator. FIG. 5B is an explanatory diagram of the operation of the microbubble generator. The lubrication device 1-2 for the internal combustion engine according to the reference example 2 shown in FIG. 4 differs from the lubrication device 1-1 for the internal combustion engine according to the reference example 1 shown in FIG. The amount of bubble mixing is controlled by the operating state of the internal combustion engine. Here, the basic configuration of the internal combustion engine lubrication device 1-2 according to Reference Example 2 shown in FIG. 4 is the same as the basic configuration of the internal combustion engine lubrication device 1-1 according to Reference Example 1 shown in FIG. The description of the portion is omitted.

The microbubble generator 6 of the internal combustion engine lubrication device 1-2 according to the reference example 2 is in the middle of the oil supply path 3, in the reference example 2 , the oil supply passage 32 on the upstream side of the oil pump 31, that is, the oil pump 31. Is provided on the suction side. The microbubble generator 6 includes an air introduction passage 61 and an air valve 62 that constitute a gas introduction device, and an ultrasonic generator 63.

  The air introduction passage 61 constitutes a part of the gas introduction device. One end of the air introduction passage 61 is released to the outside of the lubricating device 1-2 of the internal combustion engine, and a plurality of thin tubes 61a are formed at the other end. The plurality of thin tubes 61a are introduction portions, and have a diameter of, for example, about several millimeters of commas. The tip of this narrow tube 61 a opens into the oil supply passage 32 on the upstream side of the oil pump 31. Accordingly, air bubbles are formed at the tip of the narrow tube 61a by the air outside the lubricating device 1-2 of the internal combustion engine that has passed through the air introduction passage 61. Here, when the oil pump 31 sucks oil in the oil supply passage 32 on the upstream side of the oil pump 31, a negative pressure is generated in the oil pump 31. Accordingly, the air outside the lubrication device 1-2 of the internal combustion engine is sucked into the air introduction passage 61 because the plurality of thin tubes 61a are open to the oil supply passage 32 on the upstream side of the oil pump 31, and the plurality of the thin tubes 61a are sucked. The sucked air bubbles are formed at the tip of the thin tube 61a.

  The air valve 62 constitutes a part of the gas introduction device, and is provided in the middle of the air introduction passage 61. The air valve 62 is opened / closed based on an air valve opening / closing signal output from the control device 5.

  The ultrasonic generator 63 is an ultrasonic generator, and generates ultrasonic waves that vibrate the bubbles formed in the plurality of thin tubes 61a that are the introduction portions. The ultrasonic generator 63 is composed of an oscillator and an oscillation circuit (not shown), for example. The oscillator (not shown) is provided such that the focal point of the oscillator (the focal point of the ultrasonic wave generated by the oscillator) is a bubble formed in the plurality of thin tubes 61a. This oscillator is connected to an oscillation circuit (not shown), and operates according to an oscillator activation signal output from the control device 5 to the oscillation circuit. Here, as shown in FIG. 5B, the ultrasonic wave is a frequency at which surface waves can be generated in the bubbles formed in the plurality of thin tubes 61a and the microbubbles M can be separated from the wave fronts. This frequency differs depending on the type of gas constituting the microbubble M. That is, the ultrasonic generator 63 can generate an ultrasonic wave having a frequency corresponding to the gas constituting the microbubble M.

  As shown in FIG. 4, the control device 5 can obtain the engine speed Ne of the internal combustion engine, the load L of the internal combustion engine, and the oil temperature To of the oil via the input / output unit 51. Here, the engine speed Ne and the load L of the internal combustion engine can be obtained from an ECU that controls the operation of the internal combustion engine. The engine speed Ne of the internal combustion engine can be calculated based on, for example, the crank angle of the crankshaft of the internal combustion engine detected by a crank angle sensor. The load L of the internal combustion engine can be calculated based on the engine speed Ne and the opening degree of the accelerator pedal detected by the accelerator sensor. Further, the oil temperature To of the oil can be obtained by detecting the oil temperature of the oil in a portion where the oil circulates, for example, in the middle of the oil pan 2 or the oil supply passage 32, using an oil temperature sensor.

Next, the operation of the lubricating device 1-2 for the internal combustion engine according to the reference example 2 will be described. In particular, a method for controlling the microbubble generator 6 will be described. FIG. 6 is a diagram illustrating a control flow of the microbubble generator according to the second reference example .

  First, as shown in the figure, the bubble generation control unit 55 of the processing unit 52 of the control device 5 acquires the engine speed Ne, the load L, and the oil temperature To (step ST201).

Next, the bubble generation control unit 55 of the processing unit 52 calculates a target bubble mixing amount S (step ST202). Here, the bubble generation control unit 55 calculates the target bubble mixing amount S with respect to the lubricating oil by the microbubble generator 6 based on the acquired engine speed Ne, load L, and oil temperature To of the oil. In this reference example 2 , the target bubble mixing amount S is calculated from the relational expression S = F (Ne, L, To) of the engine speed Ne, the load L, and the oil temperature To.

  Here, the relational expression S = F (Ne, L, To) is determined so that the higher the engine speed Ne of the internal combustion engine is, the more S, that is, the target bubble mixture amount is increased. Further, the relational expression S = F (Ne, L, To) is determined so that the target bubble mixture amount increases as the load L of the internal combustion engine decreases. Furthermore, the relational expression S = F (Ne, L, To) is determined so that the lower the oil temperature To of the oil, the more S, that is, the target bubble mixture amount increases. In other words, the more oil is supplied to the lubrication part, and the thicker the oil film in the lubrication part (the more difficult the oil film breakage of the lubrication part), the more S, that is, the target bubble mixing amount increases. It has been decided.

Next, the bubble generation control unit 55 of the processing unit 52 calculates the valve opening period ta of the air valve 62 from the calculated target bubble mixing amount S (step ST203). In this reference example 2 , the valve opening period ta is calculated from the relational expression ta = F (S) of the target bubble mixture amount S calculated from the relational expression S = F (Ne, L, To). Here, the relational expression ta = F (S) is determined so that as the target bubble mixture amount S increases, ta, that is, the valve opening period of the air valve 62 becomes longer. The valve opening period ta of the air valve 62 is a period with respect to the control cycle to of the microbubble generator 6 by the control device 5, and ta ≦ to.

  Next, the bubble generation control unit 55 of the processing unit 52 determines whether or not the calculated target bubble mixing amount S is larger than 0 (step ST204). That is, the bubble generation control unit 55 determines whether, for example, the microbubble generator 6 does not need to generate microbubbles M when the internal combustion engine is stopped. Here, when the internal combustion engine is in a stopped state, the engine speed Ne, the load L, and the like are 0, and the relational expression S = F (Ne, L, To) = 0.

  Next, when the bubble generation control unit 55 of the processing unit 52 determines that the calculated target bubble mixing amount S is greater than 0, the ultrasonic generation device 63 generates an ultrasonic wave (step ST205). Here, the bubble generation control unit 55 outputs an oscillator operation signal to an oscillation circuit (not shown), and this oscillation circuit causes an oscillator (not shown) to generate ultrasonic waves.

  Next, the bubble generation control unit 55 of the processing unit 52 opens the air valve 62 (step ST206). Here, the bubble generation control unit 55 outputs an air valve opening / closing signal to the air valve 62 to open the air valve 62. As shown in FIG. 5A, when the air valve 62 is opened in a state where the oil pump 31 is driven, that is, when the operation of the internal combustion engine is controlled, a negative pressure generated in the air introduction passage 61 is caused. The air outside the lubricating device 1-2 of the internal combustion engine is sucked into the air introduction passage 61. As shown in FIG. 5B, air bubbles are formed at the tips of the plurality of thin tubes 61a by the sucked air. At this time, since the ultrasonic wave is generated toward the bubble by the ultrasonic wave generator 63 as described above, a surface wave is generated in the bubble, and the microbubble M is separated from the wave front. appear. The generated microbubbles M are mixed in the lubricating oil, the lubricating oil mixed with the microbubbles M is sucked into the oil pump 31, the lubricating oil mixed with the microbubbles M is discharged from the oil pump 31, and the oil supply path 3 Is supplied to each lubricating part. Thereby, the microbubble M can be stably mixed in the lubricating oil.

  At this time, the air introduction passage 61 constituting a part of the gas introduction device forms bubbles on the suction side of the oil pump 31 for circulating the lubricating oil to the internal combustion engine. Therefore, the formed bubbles themselves are also introduced into the lubricating oil sucked by the oil pump 31. Here, the bubbles in the lubricating oil are sucked into the oil pump 31. By the way, the members constituting the oil pump 31 include members that relatively move to suck and discharge the lubricating oil, such as a casing, an external gear, and a rotor. Therefore, the bubbles in the lubricating oil are sheared by the relative moving member when passing between the relative moving members. Microbubbles are further generated by this shearing force, and the generated microbubbles are mixed in the lubricating oil discharged from the oil pump 31. Thereby, microbubbles can be further stably mixed into the lubricating oil.

  Next, the bubble generation control unit 55 of the processing unit 52 determines whether or not the calculated valve opening period ta has elapsed since the air valve 62 was opened (step ST207). Therefore, the bubble generation control unit 55 maintains the open state of the air valve 62 until the calculated valve opening period ta elapses after the air valve 62 is opened.

  Next, when the bubble generation control unit 55 of the processing unit 52 determines that the calculated valve opening period ta has elapsed since the air valve 62 was opened, the ultrasonic generation device 63 stops generating ultrasonic waves. (Step ST208). Even if the bubble generation control unit 55 of the processing unit 52 determines that the calculated target bubble mixing amount S is 0, the ultrasonic generation unit 63 stops generating ultrasonic waves.

  Next, the bubble generation control unit 55 of the processing unit 52 closes the air valve 62 (step ST209). As a result, the mixing of the microbubbles M in the control cycle to ends. The control device 5 repeats this operation every control cycle to.

  As described above, the control device 5 increases or decreases the bubble mixing amount S with respect to oil by the microbubble generator 6 according to the operating state of the internal combustion engine. Therefore, the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, loss due to friction with respect to the driving force output from the internal combustion engine can be reduced, and the lubrication part in which the mixed lubrication is performed can be reduced. Oil film breakage can be suppressed, and a decrease in seizure resistance between members constituting the lubrication portion can be suppressed.

It will now be described lubricating device 1-3 for an internal combustion engine according to the reference example 3. FIG. 7 is a diagram illustrating a configuration example of a lubricating device for an internal combustion engine according to Reference Example 3 . The lubrication device 1-3 for the internal combustion engine according to Reference Example 3 shown in the figure is different from the lubrication device 1-2 for the internal combustion engine according to Reference Example 2 shown in FIG. The bubble mixing amount is controlled not only according to the rotational speed Ne, the load L, and the oil temperature To but also the viscosity of the oil (oil viscosity index Ro). Here, the basic configuration of the lubricating device 1-3 for the internal combustion engine according to the reference example 3 shown in FIG. 7 is the same as the basic configuration of the lubricating device 1-2 for the internal combustion engine according to the reference example 2 shown in FIG. The description of the portion is omitted.

  The viscosity Ro of the oil affects the thickness of the oil film in the lubrication part. The thickness of the oil film in the lubrication part becomes thinner as the viscosity of the oil is lower. The viscosity of the oil varies depending on the brand of the oil used in the internal combustion engine, aging deterioration, the oil temperature used, that is, the oil temperature To of the oil. Therefore, it is preferable to control the bubble mixing amount also by the viscosity of the oil.

As shown in FIG. 7, the control device 5 of the internal combustion engine lubrication device 1-3 according to the reference example 3 has an engine speed Ne of the internal combustion engine, a load L of the internal combustion engine, and an oil supply via an input / output unit 51. Not only the oil temperature To but also the oil pressure Po can be acquired. Here, the oil pressure Po can be obtained by detecting, with a pressure sensor, the oil sucked and discharged by the oil pump 31, for example, the oil pressure in the oil supply passage 32 on the discharge side of the oil pump 31.

Next, the operation of the lubricating device 1-3 for an internal combustion engine according to Reference Example 3 will be described. In particular, a method for controlling the microbubble generator 6 will be described. FIG. 8 is a diagram illustrating a control flow of the microbubble generator according to Reference Example 3 . Among the basic operation of the lubricating device 13 for an internal combustion engine according to the reference example 3 shown in FIG. 8, the basic operation of the same portion of the lubricating apparatus 1-2 for the internal combustion engine according to the reference example 2 shown in FIG. 6 Will simplify the description.

  First, as shown in the figure, the bubble generation control unit 55 of the processing unit 52 of the control device 5 acquires the engine speed Ne, the load L, the oil temperature To of the oil, and the oil pressure Po of the oil (step ST301).

Next, the bubble generation control unit 55 of the processing unit 52 calculates the oil viscosity index Ro (step ST302). Here, the bubble generation control unit 55 is an oil viscosity index that is an index related to the viscosity of the oil circulating through the internal combustion engine, based on the oil pressure Po, the engine speed Ne, and the oil temperature To of the oil acquired. Calculate Ro. In the reference example 3, calculates oil pressure Po, the engine speed Ne, relationship Ro = F oil temperature To of the oil (Po, Ne, To) of the oil viscosity index Ro from. The oil viscosity index Ro may be estimated, that is, calculated from the oil temperature To of the oil and at least one of the oil pressure Po and the engine speed Ne of the internal combustion engine.

Next, the bubble generation control unit 55 of the processing unit 52 calculates a target bubble mixing amount S ′ (step ST303). Here, the bubble generation control unit 55 determines the target bubble mixing amount S with respect to the lubricating oil by the microbubble generator 6 based on the acquired engine speed Ne, load L, oil temperature To, and oil viscosity index Ro. 'Is calculated. In this reference example 3 , the target bubble mixture amount S ′ is calculated from the relational expression S ′ = F (Ne, L, To) × Ro of the engine speed Ne, the load L, the oil temperature To, and the oil viscosity index Ro. .

  Here, the relational expression S ′ = F (Ne, L, To) × Ro is that the load L of the internal combustion engine decreases as the engine speed Ne of the internal combustion engine increases as described above. It is determined that S ′, that is, the target bubble mixing amount increases as the oil temperature To of the oil decreases. Further, it is determined that S ′, that is, the target bubble mixing amount increases as the oil viscosity index Ro increases, that is, as the oil viscosity increases.

Next, the bubble generation control unit 55 of the processing unit 52 calculates the valve opening period ta of the air valve 62 from the calculated target bubble mixing amount S ′ (step ST304). In the reference example 3 , the valve opening period ta is calculated from the relational expression ta = F (S ′) of the target bubble mixing amount S ′ calculated from the relational expression S ′ = F (Ne, L, To) × Ro. . Here, the relational expression ta = F (S ′) is determined so that as the target bubble mixture amount S ′ increases, ta, that is, the valve opening period of the air valve 62 becomes longer.

  Next, the bubble generation control unit 55 of the processing unit 52 determines whether or not the calculated target bubble mixing amount S ′ is larger than 0 (step ST305).

  Next, when the bubble generation control unit 55 of the processing unit 52 determines that the calculated target bubble mixing amount S ′ is greater than 0, the ultrasonic generator 63 generates an ultrasonic wave (step ST306).

  Next, the bubble generation control unit 55 of the processing unit 52 opens the air valve 62 (step ST307). Thereby, the microbubble M generate | occur | produces and it mixes in lubricating oil.

  Next, the bubble generation control unit 55 of the processing unit 52 determines whether or not the calculated valve opening period ta has elapsed since the air valve 62 was opened (step ST308).

  Next, when the bubble generation control unit 55 of the processing unit 52 determines that the calculated valve opening period ta has elapsed since the air valve 62 was opened, the ultrasonic generation unit 63 stops generating ultrasonic waves. (Step ST309). Note that the bubble generation control unit 55 of the processing unit 52 stops the generation of ultrasonic waves by the ultrasonic generator 63 even if the calculated target bubble mixing amount S ′ is determined to be zero.

  Next, the bubble generation control unit 55 of the processing unit 52 closes the air valve 62 (step ST310). As a result, the mixing of the microbubbles M in the control cycle to ends. The control device 5 repeats this operation every control cycle to.

  As described above, the control device 5 increases or decreases the bubble mixing amount S ′ with respect to the oil by the microbubble generator 6 even based on the operating state of the internal combustion engine, particularly the viscosity of the oil. Therefore, the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, loss due to friction with respect to the driving force output from the internal combustion engine can be reduced, and the lubrication part in which the mixed lubrication is performed can be reduced. Oil film breakage can be suppressed, and a decrease in seizure resistance between members constituting the lubrication portion can be suppressed.

Next, an internal combustion engine lubrication device 1-4 according to an embodiment will be described. Figure 9 is a diagram illustrating a configuration example of a lubrication system for an internal combustion engine according to the embodiment. The lubrication device 1-4 for the internal combustion engine according to the embodiment shown in the figure is different from the lubrication device 1-2 for the internal combustion engine according to the reference example 2 shown in FIG. It is a point which controls the bubble mixing amount according to the bubble mixing amount. Here, in the basic configuration of the internal combustion engine lubrication device 1-4 according to the embodiment shown in FIG. 9, the same parts as the basic configuration of the internal combustion engine lubrication device 1-2 according to Reference Example 2 shown in FIG. The description is omitted.

  When the lifetime of the microbubbles M mixed in the oil is long, the microbubbles M may be mixed in the oil supplied to the lubrication unit and returning to the oil pan 2. Therefore, in this case, if the bubble mixing amount is controlled only by the operating state of the internal combustion engine, the actual bubble mixing amount may increase. Therefore, it is preferable to control the bubble mixing amount also by the current bubble mixing amount.

As shown in FIG. 7, the internal combustion engine lubrication device 1-4 according to the embodiment includes a bubble mixing amount acquisition unit 54 in the processing unit 52 of the control device 5, and includes the oil level sensor 7.

  The oil level sensor 7 is a sensor that detects the oil level height Ho of the oil pan 2. The oil level height Ho of the oil pan 2 detected by the oil level sensor 7 is output to the control device 5. Here, in the oil in which the same amount of microbubbles M is mixed with the oil in which the microbubbles M are not mixed, the volume of the oil in which the microbubbles M are mixed is large because the microbubbles M are mixed. Therefore, when the microbubbles M are mixed in the oil stored in the oil pan 2, the oil level height Ho is higher than when the microbubbles M are not mixed. Further, as the bubble mixing amount increases, the oil volume increases and the oil level height Ho increases. That is, the amount of bubble mixing is detected based on the oil level height Hoi of the oil pan 2 before mixing the microbubbles M and the oil level height Hor of the oil pan 2 after mixing the microbubbles M. Can do.

Next, the operation of the lubrication apparatus 1-4 for the internal combustion engine according to the embodiment. In particular, a method for controlling the microbubble generator 6 will be described. FIG. 10 is a diagram illustrating a control flow of the microbubble generator according to the embodiment . Among the basic operations of the internal combustion engine lubrication device 1-4 according to the embodiment shown in FIG. 10, the same parts as the basic operation of the internal combustion engine lubrication device 1-2 according to Reference Example 2 shown in FIG. The explanation will be simplified.

  First, in the processing unit 52 of the control device 5, as shown in the figure, the bubble mixing amount acquisition unit 54 acquires the oil level height Ho, and the bubble generation control unit 55 detects the engine speed Ne, the load L, and the oil level. Oil temperature To is acquired (step ST401).

  Next, the bubble mixing amount acquisition unit 54 of the processing unit 52 determines whether or not it is after microbubble mixing (step ST402). Here, it is determined whether the acquired oil level height Ho is one before the mixing of the microbubbles M or after the mixing of the microbubbles M.

  Next, when the bubble mixing amount acquisition unit 54 of the processing unit 52 determines that the microbubbles are not mixed, the acquired oil level height Ho is set as the oil level height Hoi before the mixing of the microbubbles M (step) ST403). That is, Hoi = Ho.

  If the bubble mixing amount acquisition unit 54 of the processing unit 52 determines that the microbubbles are mixed, the acquired oil level height Ho is set as the oil level height Hor after mixing the microbubbles M (step ST404). ). That is, it is assumed that Hor = Ho.

Next, the bubble mixing amount acquisition unit 54 of the processing unit 52 calculates the current bubble mixing amount Sr (step ST405). Here, the bubble mixing amount acquisition unit 54 calculates the current bubble mixing amount Sr based on the acquired oil level height Hoi before mixing the microbubbles M and the oil level height Hor after mixing the microbubbles M. calculate. In this embodiment , the current bubble mixture amount Sr from the relational expression Sr = F (Hor-Hoi) of the oil level height Hoi before mixing of the acquired microbubbles M and the oil level height Hor after mixing of the microbubbles M. Is calculated. In addition, when it is before mixing of the microbubble M, the oil level height after mixing of the microbubble M becomes Hor = 0, and the relational expression Sr = F (Hor−Hoi) = 0.

  Here, the relational expression Sr = F (Hor−Hoi) indicates that the oil level height Hor after mixing the microbubbles M is increased with respect to the oil level height Hoi before mixing the microbubbles M as described above. It is determined that Sr, that is, the bubble mixing amount increases as the number of times increases.

Next, the bubble generation control unit 55 of the processing unit 52 calculates a target bubble mixing amount S (step ST406). Here, the bubble generation control unit 55 calculates the target bubble mixing amount S with respect to the lubricating oil by the microbubble generator 6 based on the acquired engine speed Ne, load L, and oil temperature To of the oil. In this embodiment , the target bubble mixing amount S is calculated from the relational expression S = F (Ne, L, To) of the engine speed Ne, the load L, and the oil temperature To.

  Here, as described above, the relational expression S = F (Ne, L, To) indicates that as the engine speed Ne of the internal combustion engine increases or as the load L of the internal combustion engine decreases, the oil It is determined that S ′, that is, the target bubble mixing amount, increases as the oil temperature To decreases.

Next, the bubble generation control unit 55 of the processing unit 52 calculates the valve opening period ta ′ of the air valve 62 from the calculated current bubble mixing amount Sr and the target bubble mixing amount S (step ST407). In this embodiment , the relational expression ta ′ of the current bubble mixture amount Sr calculated from the relational expression Sr = F (Hor−Hoi) and the target bubble mixture amount S calculated from S = F (Ne, L, To). = Open valve period ta ′ is calculated from F (S−Sr). That is, the relational expression ta ′ = F (S−Sr) is such that as the target bubble mixing amount S increases with respect to the current bubble mixing amount Sr, ta ′, that is, the valve opening period of the air valve 62 becomes longer. It has been decided.

  Next, the bubble generation control unit 55 of the processing unit 52 determines whether or not the difference between the calculated target bubble mixing amount S and the current bubble mixing amount Sr is larger than 0 (step ST408).

  Next, when the bubble generation control unit 55 of the processing unit 52 determines that the difference between the calculated target bubble mixing amount S and the current bubble mixing amount Sr is larger than 0, the ultrasonic generator 63 generates ultrasonic waves. Occurs (step ST409).

  Next, the bubble generation control unit 55 of the processing unit 52 opens the air valve 62 (step ST410). Thereby, the microbubble M generate | occur | produces and it mixes in lubricating oil.

  Next, the bubble generation control unit 55 of the processing unit 52 determines whether or not the calculated valve opening period ta ′ has elapsed since the air valve 62 was opened (step ST411).

  Next, when the bubble generation control unit 55 of the processing unit 52 determines that the calculated valve opening period ta ′ has elapsed since the air valve 62 was opened, the ultrasonic generator 63 stops generating ultrasonic waves. (Step ST412). Even if the bubble generation control unit 55 of the processing unit 52 determines that the difference between the calculated target bubble mixing amount S and the current bubble mixing amount Sr is 0, the ultrasonic wave generation by the ultrasonic generator 63 is performed. Stop generating.

  Next, the bubble generation control unit 55 of the processing unit 52 closes the air valve 62 (step ST413). As a result, the mixing of the microbubbles M in the control cycle to ends. The control device 5 repeats this operation every control cycle to.

  As described above, the control device 5 increases or decreases the amount of bubbles mixed into the oil by the microbubble generator 6 based on the oil level height Ho of the oil pan 2 detected before and after the mixing of the microbubbles M, respectively. For example, when the detected current bubble mixing amount Sr is equal to or larger than the target bubble mixing amount S, the control device 5 stops the generation of the micro bubbles M by the micro bubble generating device 6. Therefore, since the amount of bubbles mixed in the actual oil can be maintained at an appropriate value, the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, and the friction against the driving force output from the internal combustion engine can be reduced. In addition, the loss of the oil film in the lubrication part where the mixed lubrication is performed can be suppressed, and the decrease in seizure resistance between the members constituting the lubrication part can be suppressed.

In the internal combustion engine lubrication apparatus 1-4 according to the above embodiment , the oil level height Hoi before mixing the microbubbles M detected by the oil level sensor 7 and the oil level height Hor after mixing the microbubbles M are detected. The present bubble mixing amount Sr is detected based on the above, but the present invention is not limited to this. For example, the current bubble mixing amount Sr may be detected based on the intensity of transmitted light of oil circulating through the internal combustion engine. When the oil is irradiated with light, if the microbubbles M are mixed in the oil, the transmitted light that passes through the oil is scattered by the microbubbles M. As the amount increases, it decreases. That is, it is possible to detect the amount of bubbles mixed into the oil by the change in the intensity of the transmitted light of the oil.

  In this case, a light source for irradiating light circulated through the internal combustion engine, for example, oil passing through the oil supply passage 32, and an optical sensor for detecting the intensity of transmitted light of the oil are further provided. The control device 5 increases or decreases the bubble mixing amount S with respect to the oil by the microbubble generator 6 based on the intensity of the transmitted light of the oil. For example, when the current bubble mixing amount Sr detected based on the intensity of transmitted light of oil is equal to or greater than the target bubble mixing amount S, the control device 5 stops the generation of the microbubbles M by the microbubble generating device 6. Therefore, since the amount of bubbles mixed in the actual oil can be maintained at an appropriate value, the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, and the friction against the driving force output from the internal combustion engine can be reduced. In addition, the loss of the oil film in the lubrication part where the mixed lubrication is performed can be suppressed, and the decrease in seizure resistance between the members constituting the lubrication part can be suppressed.

Also in the internal combustion engine lubrication device 1-4 according to the above embodiment , similarly to the internal combustion engine lubrication device 1-3 according to the reference example 3 , the control device 5 operates the internal combustion engine, that is, the engine. The bubble mixing amount may be controlled in accordance with not only the rotation speed Ne, the load L, and the oil temperature To of the oil but also the viscosity of the oil (oil viscosity index Ro).

Further, in the internal combustion engine lubrication devices 1-2 to 1-4 according to the above-described examples and reference examples 2 and 3 , the target bubble mixture amounts S and S ′, the valve opening periods ta and ta ′, and the oil viscosity index are obtained from the relational expressions. Ro and the current bubble mixing amount Sr are calculated, but the present invention is not limited to this. For example, in the storage unit 53 of the control device 5, the target bubble mixture amount map based on the engine speed Ne, the load L, and the oil temperature To of the oil in advance, the engine speed Ne, the load L, the oil temperature To of the oil, the oil viscosity index A target bubble mixing amount map based on Ro, a valve opening period map based on the target bubble mixing amount S or the target bubble mixing amount S ′, an engine speed Ne, an oil temperature To of oil, an oil viscosity index map based on the oil pressure Po of oil, A current bubble mixture amount map based on the oil level height Hoi before mixing of the microbubbles M, the oil level height Hor after mixing of the microbubbles M may be stored. The processing unit 52 of the control device 5 may calculate the target bubble mixing amount S, S ′, the valve opening period ta, ta ′, the oil viscosity index Ro, and the current bubble mixing amount Sr from these maps.

Next, an internal combustion engine lubrication device 1-5 according to Reference Example 4 will be described. Figure 11 is a diagram showing a configuration example of a lubrication system for an internal combustion engine according to Reference Example 4. 4 differs from the internal combustion engine lubrication device 1-2 according to the reference example 2 shown in FIG. 4 in that the microbubbles are provided in the lubrication part of the internal combustion engine. It is a point that can circulate two kinds of oil, oil mixed with oil and oil not mixed. Here, the basic configuration of the lubricating device 1-5 for the internal combustion engine according to the reference example 4 shown in FIG. 11 is the same as the basic configuration of the lubricating device 1-2 for the internal combustion engine according to the reference example 2 shown in FIG. The description of the portion is omitted.

As shown in FIG. 11, the lubricating device 1-5 for the internal combustion engine according to the reference example 4 includes the oil supply path 3 provided with the microbubble generator 6 and the oil supply path not provided with the microbubble generator 6. 8 is provided. That is, the internal combustion engine lubrication device 1-5 according to the reference example 4 is not mixed with the oil supply path 3 constituting the mixing side circulation path for circulating the oil mixed with the microbubble M and the microbubble M. And an oil supply path 8 constituting a non-mixing side circulation path for supplying lubricating oil.

  The oil supply path 8 supplies oil to the valve operating lubrication unit and circulates it. The oil supply path 8 includes an oil pump 81 and an oil supply path 82, as with the oil supply path 3. The oil pump 81 is for pressure-feeding the oil stored in the oil pan 2 to the valve train lubrication unit. The oil supply passage 82 communicates the oil pan 2 and the valve system lubrication unit via the oil pump 81. Here, the valve system lubrication part is a lubrication part located in the cylinder head, such as between the cylinder head and the intake / exhaust valve, between the cylinder head and the camshaft, and between the intake / exhaust valve and the cam. Lubrication part. The oil supply path 3 supplies oil to the crankshaft circulation section and circulates it. Here, the valve train lubrication part is a lubrication part such as between the cylinder block and the piston, between the piston and the connecting rod, or between the connecting rod and the crankshaft.

The lubrication part between the intake / exhaust valve and the cam, which is a valve-operated lubrication part, is a lubrication part in which mixed lubrication including fluid lubrication and boundary lubrication is performed in a state in which the term session Ne of the internal combustion engine is low. The lubrication portion where the mixed lubrication is performed is a lubrication portion in which oil film breakage is likely to occur. That is, the lubricating device 1-5 for an internal combustion engine according to the reference example 4 supplies and circulates oil, in which the microbubbles M are not mixed, through the oil supply path 8 to the lubricating portion where oil film breakage is likely to occur. Further, oil mixed with microbubbles M is supplied by the oil supply device 3 to the crankshaft lubrication portion where the oil film breakage hardly occurs and is circulated. Therefore, the frictional resistance can be reduced more than the frictional resistance of the lubrication part when liquid lubrication is performed, and the loss due to the friction with respect to the driving force output from the internal combustion engine can be reduced. In addition, the oil in which the microbubbles M are not mixed can suppress the oil film breakage of the oil in which the mixed lubrication including the fluid lubrication and the boundary lubrication is performed. The decrease can be suppressed.

In the reference example 4 , the oil stored in the oil pan 2 is supplied and circulated to the valve system lubrication unit and the crankshaft system lubrication unit in both the oil supply paths 3 and 8, but the oil pan is provided separately. May be. In the reference example 4 , the oil supply paths 3 and 8 supply the oil and circulate the lubrication part into the valve system lubrication part and the crankshaft system lubrication part. However, the present invention is not limited to this. Oil that does not contain the microbubbles M may be supplied from the oil supply path 8 to a lubrication portion where oil film breakage easily occurs, that is, a lubrication portion that performs mixed lubrication including fluid lubrication and boundary lubrication.

The above example, in Reference Examples 2 to 4, the microbubble generator 6, in order to forcibly formed air bubbles, may be provided with a pump. In this case, the microbubble generator 6 can be provided on the discharge side of the oil pump 31. In addition, the microbubble generator 6 may not include the ultrasonic generator 63 when the microbubble M can be sufficiently generated by the shearing force of the oil pump 31. That is, the microbubble generator 6 may be configured by the air introduction passage 61 and the air valve 62. Further, when the microbubbles M can be sufficiently generated by the shearing force of the oil pump 31, by forming a plurality of fine holes in a casing (not shown) of the oil pump 61, for example, May be formed.

  As described above, the lubrication device for an internal combustion engine according to the present invention is useful for a lubrication device for an internal combustion engine that reduces friction in a lubrication portion of the internal combustion engine, and in particular, loss due to friction with respect to the driving force output from the internal combustion engine. Suitable for reducing

It is a figure which shows the structural example of the lubricating device of the internal combustion engine concerning the reference example 1. FIG. It is a figure which shows the control flow of the microbubble generator concerning the reference example 1. FIG. It is a figure which shows the relationship between a frictional force and the bubble mixing amount. It is a figure which shows the structural example of the lubricating device of the internal combustion engine concerning the reference example 2. FIG. It is a figure which shows the structural example of a microbubble generator. It is operation | movement explanatory drawing of a microbubble generator. It is a figure which shows the control flow of the microbubble generator concerning the reference example 2. FIG. It is a figure which shows the structural example of the lubricating device of the internal combustion engine concerning the reference example 3. FIG. It is a figure which shows the control flow of the microbubble generator concerning the reference example 3. FIG. Is a diagram illustrating a configuration example of a lubrication system for an internal combustion engine according to the embodiment. It is a figure which shows the control flow of the microbubble generator concerning an Example . Is a diagram illustrating a configuration example of a lubrication system for an internal combustion engine according to the second embodiment.

1 Lubrication device 2 Oil pan (lubricating oil storage chamber)
3 Oil supply path (mixing side circulation path)
31 Oil pump 32 Oil supply passage 33 Bubble mixing amount sensor (Bubble mixing amount detecting means)
DESCRIPTION OF SYMBOLS 4 Microbubble generator 41 Mixing tank 42 Bubble pump 43 Gas suction passage 44 Oil suction passage 45 Bubble discharge passage 46 Suction control valve 47 Discharge control valve 5 Control device (bubble generation control means)
REFERENCE SIGNS LIST 51 Input / output unit 52 Processing unit 53 Storage unit 54 Bubble mixing amount acquisition unit 55 Bubble generation control unit 6 Microbubble generation device (microbubble generation means)
61 Air introduction passage 62 Air valve 63 Ultrasonic generator (Ultrasonic generator)
7 Oil level sensor 8 Oil supply path (non-mixing side circulation path)
81 Oil pump 82 Oil supply passage

Claims (8)

In a lubricating device for an internal combustion engine that circulates lubricating oil in the internal combustion engine and lubricates the internal combustion engine,
Microbubble generating means for generating microbubbles ;
Bubble generation control means for controlling the generation of microbubbles by the microbubble generation means;
An oil level sensor for detecting the oil level of a lubricating oil storage chamber for storing lubricating oil circulated through the internal combustion engine ;
The bubble generation control means is based on any one of the engine speed, load or oil temperature of the lubricating oil of the internal combustion engine and the oil level height of the lubricating oil storage chamber detected before and after mixing the microbubbles. Te, the microbubble generating means to control the bubble mixing amount due for the lubricating oil, the lubricating apparatus characterized by the microbubbles mixed into the lubricating oil above occurred. In a lubricating device for an internal combustion engine that circulates lubricating oil in the internal combustion engine and lubricates the internal combustion engine,
Microbubble generating means for generating microbubbles;
Bubble generation control means for controlling the generation of microbubbles by the microbubble generation means;
A light source for irradiating the lubricating oil circulating in the internal combustion engine with light, and an optical sensor for detecting the intensity of transmitted light of the lubricating oil;
With
The bubble generation control means is based on any one of an engine speed, a load or an oil temperature of the lubricating oil of the internal combustion engine, and the detected intensity of transmitted light of the lubricating oil. by controlling the bubble mixing amount with respect to the lubricating oil by, to that lubrication device, characterized in that the microbubbles mixed into the lubricating oil above occurred. The microbubble generating means is
A gas introduction device having an introduction part for forming bubbles in the circulating lubricating oil;
An ultrasonic generator that generates ultrasonic waves that vibrate bubbles formed in the introduction portion;
Lubrication system for an internal combustion engine according to claim 1 or 2, characterized in that it comprises a. The gas introduction device, the lubricating system of an internal combustion engine according to claim 3, wherein the benzalkonium to introduce bubbles into the lubricating oil to be sucked to the lubricating oil to the oil pump for circulating the internal combustion engine. 3. The internal combustion engine according to claim 1 , wherein the microbubble generating means is a gas introduction device that introduces bubbles into the lubricating oil sucked by an oil pump that circulates the lubricating oil to the internal combustion engine. Lubrication equipment. The lubrication of an internal combustion engine according to any one of claims 1 to 5, wherein the generated microbubbles are mixed in a lubricating oil in a lubricating oil storage chamber for storing lubricating oil circulated through the internal combustion engine. apparatus. A mixed side circulation path for circulating the lubricating oil in which the microbubbles are mixed, according to claim 6, characterized in that it comprises a non-contaminated side circulation path for supplying lubricating oil to the microbubbles is not mixed A lubricating device for an internal combustion engine according to any one of the above.   The bubble generation control means is based on the viscosity of the lubricating oil estimated from the oil temperature of the lubricating oil and at least one of the pressure of the lubricating oil or the engine speed of the internal combustion engine. The internal combustion engine lubrication device according to any one of claims 1 to 7, wherein an amount of bubbles mixed in the lubricating oil by the generating means is controlled.

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