JP2019070379A - Accelerator for exhaust gas flow - Google Patents

Abstract

To provide an accelerator for exhaust gas flow capable of being appropriately mounted to various kinds of equipment including an internal combustion engine, and having flexibility or elasticity.SOLUTION: An accelerator 10 is installed at a terminal of an exhaust system in an internal combustion engine, and is configured to accelerate exhaust gas flow to release it to the atmosphere. The accelerator comprises: a cylindrical device body 20 of which one end is an exhaust gas inflow side where exhaust gas flow discharged from the terminal of the exhaust system is caught, and the other end is an exhaust gas outflow side where exhaust gas flow is released to the atmosphere; and a silencer 60 provided on the exhaust gas inflow side of the device body 20, for reducing noise caused by releasing exhaust gas flow to the atmosphere.SELECTED DRAWING: Figure 11

Description

  The present invention relates to an apparatus installed at the end of an exhaust system of an internal combustion engine to accelerate an exhaust gas flow and release it to the atmosphere.

  2. Description of the Related Art In an internal combustion engine represented by an automobile engine, an exhaust system plays an important role in not only releasing exhaust gas generated by combustion to the atmosphere but also adjusting exhaust gas components and reducing exhaust noise. In particular, with the progress of the legal maintenance for exhaust gas purification in recent years, the exhaust system becomes complicated and the tendency of back pressure increasing continues. The inventor of the present invention has been working on a technology for speeding up the exhaust gas and releasing it to the atmosphere in order to improve the above-mentioned tendency, and has made patent applications each time for a part of the results and made efforts to disclose the technology.

  Among them, JP-A-6-173634 is an invention for promoting scavenging by providing a bypass in the exhaust system and increasing exhaust gas flow velocity to reduce back pressure, and JP-A-7-233722 is an exhaust pipe for exhaust In order to solve the problem of heat damage, a pipe flow pipe is provided for taking out the gas and carrying out a pipe flow, Japanese Patent Application Laid-Open No. 8-326547 proposes an acceleration unit for accelerating the exhaust gas flow to generate negative pressure in upper and lower two stages. It is an invention for providing a high degree of negative pressure suction energy. Further, JP-A-9-170432 is an invention in which a throttling portion is provided to narrow the flux of the exhaust gas flow when the exhaust gas is released into the atmosphere at a high speed, thereby ensuring high-speed discharge, JP-A-10-331631 is an engine Japanese Patent Laid-Open Publication No. 2001-98924 is an invention aimed at miniaturizing a muffler having an early promoting effect, in which the invention is made flexible to cope with a certain change in displacement of the engine.

  In the process of continuing development, the outcome may not coincide with the purpose, and the result may not always be as intended, but the issues to be solved have become clearer and clearer. The representative one is, for example, the flexibility corresponding to the change of the engine displacement etc. If this is not enough, it is necessary to prepare various kinds of products depending on the magnitude of the displacement. Another problem is the miniaturization of the apparatus, and the larger the equipment, the harder it is to mount it on a car and the greater the load on the exhaust pipe. Through such a history, the inventor of the present invention knows the method for solving the above-mentioned problems, and incorporates this method into an actual device, and as a result, it is the invention of Japanese Patent Application Laid-Open No. 2011-153574. is there.

  A system consisting of such a series of inventions has been called a JVCS (registered trademark), has received a certain evaluation until now, and has been successful as a product. However, there are aspects that this system does not necessarily advance the technical elucidation even though the remarkable effect can be obtained in practice. Therefore, in order to actually apply the apparatus to each engine and obtain optimum results, it is necessary to rely on skilled technicians having appropriate experience and techniques, and therefore it is not that they can be worn by anyone. Therefore, the present inventor has continued development for an exhaust gas flow acceleration device which is easier to install and has flexibility or flexibility when applied to a vehicle or the like, and has reached the present invention.

JP-A-6-173634 JP-A-7-233722 JP-A-8-326547 JP-A-9-170432 JP 10-331631 JP 2001-98924 A JP 2011-153574 A

  The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a flexible or flexible exhaust gas flow acceleration device which can be suitably mounted on various devices provided with an internal combustion engine. .

  In order to solve the above-mentioned problems, the present invention is an accelerator installed at the end of an exhaust system of an internal combustion engine to accelerate the exhaust gas flow and release it to the atmosphere, one end of which is discharged from the end of the exhaust system. An exhaust gas inflow side that receives the exhaust gas flow, and the other end is an exhaust gas outflow side that discharges the exhaust gas flow to the atmosphere For this purpose, a means is provided which comprises a silencer provided on the exhaust gas inflow side of the apparatus body.

  Further, in order to solve the above problems, the present invention is an accelerator installed at the end of the exhaust system of an internal combustion engine to accelerate the exhaust gas flow and release it to the atmosphere, and one end is discharged from the end of the exhaust system. The exhaust gas inflow side that receives the exhaust gas flow, and the other end is the exhaust gas outflow side that discharges the exhaust gas flow to the atmosphere; A tail pipe provided on the exhaust gas outflow side of the apparatus body, and an annular impact sound absorbing device provided on the outer periphery of the tail pipe in order to reduce noise associated with the atmospheric discharge of the exhaust gas flow; The sound absorbing device has a plurality of sound absorbing tubes arranged in an annular shape, and each of the plurality of sound absorbing tubes is configured to open to an exhaust gas injection region from which the accelerated exhaust gas flow flows out. It has taken measures.

  Since the present invention is configured and operates as described above, it is possible to provide a flexible or flexible exhaust gas flow acceleration device that can be suitably mounted on various devices equipped with an internal combustion engine. Can.

It is an explanatory view showing the state where it installed in the terminal of the exhaust system of an internal-combustion engine as an example of the accelerator of the exhaust gas flow concerning a 1st embodiment of the present invention. It is a longitudinal cross-section explanatory drawing which shows the internal structure of Example 1 of an apparatus same as the above. 7 shows a cross section of the above-mentioned apparatus, in which A is a cross-sectional view taken along line IIIA-IIIA in FIG. 2 and B is a cross-sectional view taken along line IIIB-IIIB in FIG. It is a longitudinal cross-sectional view explaining the effect | action in the acceleration device of the exhaust gas flow of the said Example 1 which concerns on this invention. It is explanatory drawing which shows a mode that a negative pressure propagates in this invention. It is explanatory drawing which shows the Otto cycle in the conventional engine and the engine of this invention. FIG. 7 shows Example 2 of the apparatus applied to FIG. 1, wherein A is a longitudinal sectional view and FIG. 7 B is a sectional view taken along the line VB-VB in FIG. 7A. FIG. 8 shows Example 3 of the apparatus applied to FIG. 1, in which A is a longitudinal sectional view, and B is a sectional view taken along the line VIB-VIB in FIG. 8A. It is a longitudinal cross-section explanatory drawing which shows Example 4 of the apparatus applied to FIG. It is explanatory drawing which shows Example 5 of an apparatus same as the above. It is an explanatory view showing an example of an accelerator of exhaust gas flow concerning a 2nd embodiment of the present invention. 11 shows a cross section of the above-mentioned apparatus, in which A is a cross-sectional view taken along the line VIIA-VIIA in FIG. 11 and B is a cross-sectional view taken along the line VIIB-VIIB in FIG. It is an explanatory view showing a situation of sound absorption of an impact sound absorption device concerning a 2nd embodiment of the present invention.

  First, an outline of the present invention will be described. Conventional internal combustion engines (e.g., automobile engines) convert power into power using combustion power of fuel (gasoline, light oil, hydrogen, etc.). On the other hand, the apparatus for accelerating the flow of exhaust gas according to the present invention reinforces the conventional combustion power and drives the engine using negative pressure power and atmospheric pressure power. Therefore, the apparatus for accelerating the flow of exhaust gas according to the present invention can function as an engine (second reinforcement engine) that reinforces the conventional internal combustion engine (first basic engine) by being installed in the conventional internal combustion engine. It is possible. As described above, according to the present invention, by adding the second reinforcement engine to the conventional first basic engine, it is possible to construct an engine of maximum capacity which is completed as one. In the present invention, “negative pressure” means, for example, a pressure below the reference pressure, for example, the pressure of the exhaust gas flow flowing in the exhaust system is one reference pressure.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described with reference to the illustrated embodiment. In the first embodiment, the configuration of the exhaust gas flow acceleration device according to the present invention will be described, and in the second embodiment described later, the configuration of the exhaust gas flow acceleration device according to the first embodiment will be described. The configuration in which the cap and the silencer are added will be described.

  FIG. 1 relates to an example 1 of an accelerator 10 of an exhaust gas flow according to a first embodiment of the present invention, wherein 11 is an internal combustion engine, 12 is a combustion chamber, 13 is an exhaust pipe for discharging the generated exhaust gas, Reference numeral 14 denotes a catalyst device for exhaust gas purification, which is provided in the exhaust pipe 13. The exhaust pipe 13 is equipped with a muffler 15, and the catalyst device 14 and the exhaust pipe 13 including the muffler 15 constitute an exhaust system.

  In the present embodiment, a four-cycle gasoline engine is assumed as the internal combustion engine 11, and the accelerator 10 for the exhaust gas flow is installed at the exhaust pipe 13, that is, at the end of the exhaust system. The exhaust gas flow acceleration device 10 according to the present invention, as shown in detail in FIG. 2, comprises a device main body 20 having a hollow cylindrical structure, and the device main body 20 is located upstream of the exhaust gas flow. It is airtightly connected to the end of the exhaust pipe 13 at a connection end 16 provided at one end located in the.

  The device body 20 included in the acceleration device 10 according to the present invention has the connecting end 16 at one end on the exhaust gas inflow side for receiving the exhaust gas flow discharged from the end of the exhaust system, and the other end releases the exhaust gas to the atmosphere Exhaust gas outflow side. The apparatus main body 20 has a cylindrical structure as a whole, and is formed in a cylindrical shape including a front surface portion 17 on the exhaust gas inflow side, an intermediate cylindrical portion 18 and a rear surface portion 19 on the exhaust gas outflow side. There is.

  The connection end portion 16 is inserted into a connection hole 17 a formed in the front surface portion 17 of the apparatus main body 20 and joined by welding. The connection hole 17a is provided substantially concentrically with the device body 20 (see FIG. 3A). The joining means may be welding alone, or screw connection or their combination is also possible. Such an apparatus main body 20 is manufactured using a heat resistant metal by an arbitrary processing method such as a sheet metal processing method, a deep drawing method, a die casting method or the like.

  An exhaust gas flow acceleration cylinder 21 is provided inside such a device main body 20. An exhaust gas flow accelerating cylinder 21 is provided to accelerate mainly the flow of the central portion of the exhaust gas flow that flows in from the exhaust gas inflow side, and is connected to the connection end 16. Therefore, it is provided substantially concentric with the device body 20. The exhaust gas flow acceleration cylinder 21 in the present invention is formed to have a relatively large volume in comparison with a conventional exhaust gas flow acceleration device, and receives a larger amount of exhaust gas discharged from the exhaust system. It is configured to be able to.

  The exhaust gas flow acceleration cylinder 21 has a tapered cylindrical acceleration portion 22 and an opening portion 24 provided in the cylindrical portion 23 to flow the flow of the exhaust gas flow other than the central portion to the outside of the acceleration portion. have. The cylindrical portion 23 shown as Example 1 is substantially cylindrical. The above-mentioned relatively large volume refers to the volume related to the tapered cylindrical acceleration portion 22. For example, the volume can be increased by making the inclination angle with respect to the central axis of the tapered portion more obtuse. It can be increased. In the case of the embodiment, the volume of the exhaust gas flow accelerating cylinder 21 is set to, for example, about twice that of the second accelerating portion in the invention of the above-mentioned JP-A-2011-153574. According to the experiment, the degree of volume increase was optimal at about 100% increase over the conventional level, but the effect began to appear at 20% increase and the effect plateaued even if it exceeded 150%. It is considered that good results can be obtained.

  In the invention of the present inventor listed as the prior art, the tapered shape of the acceleration cylinder is set to a sharper inclination angle with respect to the central axis. On the other hand, although the resistance tends to increase by setting the inclination angle more as in the present invention, the exhaust gas flow that is compressible increases in speed to the critical angle, and accordingly, to the opening 24 The bypass flow rate increases. Therefore, by appropriately setting the critical angle, the acceleration in the accelerating portion 22 reaches its maximum without adversely affecting the acceleration of the exhaust gas flow, and the pressure drop generated downstream of the accelerating portion 22 is also maximized. Conventionally, the critical angle C is an angle less than 30 degrees with respect to the central axis, but in the case of the present invention, it is confirmed by experiments that it is preferably in the range of 30 to 45 degrees.

  The cylindrical portion 23 is also provided with an opening 24. The opening 24 is elongated in the central axis direction, and several of the openings 24 are equally spaced in the circumferential direction of the cylindrical portion 23. The area of the openings 24 is also an important factor, and the area of the openings 24 is preferably several times the opening area of the nozzles 25 in comparison with the opening area of the nozzles 25 of the exhaust gas flow accelerating cylinder 21. In the embodiment, the area of the opening 24 is set to four times the opening area of the nozzle 25 and good results are obtained. In the illustrated embodiment, in comparison with the cross-sectional area S0 of the end of the exhaust system: S0> Cross-sectional area S1 of the opening + cross-sectional area S2 of the rear end nozzle, ie the gas flow at the end of the exhaust system by the accelerator 10 of the present invention It is in the relationship of the cross-sectional area that can be narrowed.

  The exhaust gas flow accelerating cylinder 21 is fixed to the cylindrical portion 18 at several places in the cylindrical portion 23 using the support 26 by means such as welding. The support 26 is illustrated in a substantially cross shape in FIG. 3 (FIG. 3A) and has sufficient strength to fix the exhaust gas flow accelerating cylinder 21 against external forces such as exhaust gas flow and traveling vibration. Act as a support. A space between the supports 26 is an exhaust gas suction port 27 through which an external exhaust gas flow passes, and it passes around the acceleration portion 22 and communicates with a negative pressure space formed behind it.

  A tail pipe 28 is provided on the exhaust gas outflow side in order to release the exhaust gas flow accelerated by the exhaust gas acceleration cylinder 21 to the atmosphere. The tail pipe 28 is slidably provided in the pipe holding cylinder 29 in the front-rear direction. For this purpose, mounting holes 19a are provided substantially concentrically in the rear face portion 19, and the pipe holding cylinder 29 is inserted therein and joined by means such as welding. The pipe connection cylinder 29 is disposed in such a positional relationship that the front end overlaps or does not overlap the rear end of the exhaust gas flow acceleration cylinder 21.

  An adjustment mechanism 30 is provided to make the tail pipe 28 movable in the front-rear direction with respect to the apparatus main body 20, thereby making it possible to adjust the distance between the exhaust gas flow accelerating cylinder 21 and the tail pipe 28. . The adjustment mechanism 30 shown in FIG. 2 is an adjustment hole provided at a plurality of positions as positioning portions for the longitudinal direction of the external thread 32 and the tail pipe 28 screwed with the internal thread portion 31 formed in the pipe holding cylinder 29 and the internal thread portion 31. It consists of 33. Therefore, the position of the tail pipe 28 in the front-rear direction can be fixed by screwing the male screw body 32 to the female screw portion 32 and inserting the tip into the adjustment hole 33.

  In the exhaust gas flow accelerator 10 of Example 1 having such a configuration, the exhaust gas flow E discharged from the end of the exhaust system flows into the exhaust gas flow acceleration cylinder 21 and mainly the central portion of the exhaust gas flow. Flow E1 passes through the tapered cylindrical acceleration portion 22 and is accelerated to form a high-speed flow. With acceleration, a strong negative pressure region V is formed in the region shown by the gray line in FIG. 4 between the nozzle portion 25 and the tail pipe 28 in the periphery thereof. In the exhaust gas flow accelerating cylinder 21, the flow E2 mainly except for the central portion flows out of the acceleration portion 22, but this flow is sucked into the strong negative pressure region V to become a suction flow E3, and the central portion is high speed Flow to the air as E4.

  The area around the nozzle 25 is shown as a negative pressure area V, but the strongest negative pressure is generated in the high-speed flow E1 passing through the nozzle 25 and the negative pressure area V indicates the outer edge of the negative pressure. is there. In particular, the apparatus 10 for accelerating an exhaust gas flow according to the present invention has a configuration in which the adjustment mechanism 30 is operated to move the tail pipe 28 in the front-rear direction with respect to the apparatus main body 20. Accordingly, by adjusting the distance between the exhaust gas flow accelerating cylinder 21 and the tail pipe 28, the range of the negative pressure region V can be changed, and this change greatly affects the acceleration of the exhaust gas flow. . The position of the two-dot chain line shown in FIG. 4 shows a state where the tail pipe 28 is retracted the most, in which state the negative pressure region V is expanded to the maximum, generating a stronger negative pressure and causing exhaust gas flow The acceleration is set to the maximum limit.

  Here, the principle of acceleration of the exhaust gas flow in the exhaust gas flow acceleration device 10 of Example 1 will be described. After introducing the exhaust gas into the acceleration device 10, the acceleration device 10 of the present invention is branched into a first path (mainly the flow E1 in the central part) and a second path (flow E2 mainly the other than the central part). Do.

  In the first path, the unit volumetric flow rate of the exhaust gas is increased by forming a shape (for example, a tapered cylindrical shape) having a discharge port having a small cross-sectional area downstream, and a negative pressure ( A negative pressure region V) occurs because of the following reasons. That is, as is well known, the flow cross-sectional area of the fluid is inversely proportional to the velocity of the fluid. For example, halving the diameter of the flow section of the fluid reduces the cross-sectional area by a factor of four, the velocity of the fluid is quadrupled, and the energy of the fluid is proportional to the square of the velocity of the fluid. become. According to Bernoulli's theorem corresponding to the energy conservation law in fluid, the sum of fluid energy and pressure is equal before and after the change. For this reason, when the energy of the fluid increases, negative pressure is generated in the direction perpendicular to the flow velocity direction. That is, when the exhaust gas (mainly the flow E1 in the central part) flowing through the first path among the exhaust gas passes through the tapered cylindrical acceleration part 22, the cross-sectional area decreases and the flow velocity increases, and the energy of the fluid increases. As a result, negative pressure (negative pressure region V) is generated.

  The second path is a path branched from the first path, but the exhaust gas (mainly the flow E2 other than the central portion) flowing in the second path is drawn to the negative pressure (negative pressure region V) described above As a result, a high-speed suction flow (suction flow E3) is obtained, and the first path is joined (becoming E4). As a result, the exhaust gas introduced into the acceleration device 10 (the exhaust gas flow branched into the first path and the second path) is promoted in its entirety as a whole (the exhaust gas flow is accelerated). .

  The exhaust gas flow acceleration device 10 of the present invention can function as an engine (second reinforcement engine) that reinforces a conventional internal combustion engine (first basic engine). This will be specifically described below with reference to FIGS. 5 and 6.

  FIG. 5 is a view for explaining how negative pressure propagates when the exhaust gas flow acceleration device 10 of the present invention is installed in a conventional internal combustion engine 11 (first basic engine). In addition, in FIG. 5, the acceleration device 10 is simplified and illustrated, and the illustration of the configuration of the other exhaust system is omitted.

  As well known, according to Bernoulli's theorem, since the sum of energy of fluid and pressure is equal before and after change, the kinetic energy of the flow velocity of the fluid (exhaust gas flow) and the negative generated in the direction perpendicular to the flow velocity direction The sum of the pressure (negative pressure from the wall indicated by the solid arrow in FIG. 5) does not change (it is zero). For this reason, kinetic energy of the flow velocity of the exhaust gas flow and negative pressure from the wall surface are generated as a set. Also, the flow velocity once generated on the wall tends to continue to exist by the law of inertia. Therefore, the set of the flow velocity and the negative pressure propagates along the wall without delay to the exhaust bubble of the internal combustion engine 11 (the first basic engine), and as shown in FIG. Negative pressure will propagate to the inside.

  FIG. 6 is referred to as an Otto cycle PV diagram and is a diagram representing the performance of a 4-cycle engine. FIG. 6 (A) shows a PV diagram of a conventional engine (i.e., an internal combustion engine without the accelerator 10 of the present invention), and FIG. 6 (B) shows an engine of the present invention (i.e., the acceleration of the present invention). Fig. 1 shows a PV diagram of an internal combustion engine comprising an arrangement 10;

  In the conventional engine, as shown in FIG. 6A, the strokes of intake and exhaust do not contribute to the motive power of the engine but are rather called losses because they are losses. Specifically, as shown in FIG. 6 (A), (1) intake air and (4) exhaust gas become resistance, and take power (power) of the engine.

  On the other hand, in the engine of the present invention, as shown in FIG. 5, the negative pressure in the cylinder (solid arrow in FIG. 5) and the atmospheric pressure outside the cylinder (FIG. 5) in the exhaust stroke (the exhaust valve is open). By the action of both of the dotted arrows in Fig. 1, a force is applied in a direction to push up the piston together. For this reason, as shown in FIG. 6B, (1) intake and (4) exhaust can greatly contribute to the power (power) of the engine.

  Further, in the conventional engine, about 10% of residual gas often remains in the cylinder in the exhaust stroke. Then, the specific heat ratio decreases due to the residual gas, and the temperature rise at the time of combustion is suppressed, whereby the combustion power decreases (see FIG. 6A). On the other hand, in the engine of the present invention, it is possible to scavenge all residual gas in the piston by negative pressure and to force fresh air (oxygen) from the overlapped open intake valve so that oxygen in the cylinder The amount can be increased to increase the combustion power (see FIG. 6 (B)). The magnitude of the negative pressure depends on the flow velocity of the exhaust gas, and the flow velocity of the exhaust gas is proportional to the number of revolutions of the engine. Therefore, the engine of the present invention can obtain torque according to the rotational speed.

  From the above, the exhaust gas flow acceleration device 10 of the present invention can function as an engine (second reinforcement engine) that reinforces the conventional internal combustion engine (first basic engine), and is integrated with the conventional internal combustion engine Can become the engine of maximum ability.

  Next, with reference to FIG. 7, an example 2 of the exhaust gas flow acceleration device 10 according to the present invention will be described. The acceleration device 10 of Example 2 is also substantially the same as the device of Example 1 in terms of the basic configuration, so the reference numerals are used and the detailed description is omitted. The acceleration device 10 of Example 2 differs from the case of Example 1 in which the cross-sectional area changes continuously, in which the cross-sectional area changes stepwise (discontinuously), and specifically, the cylindrical portion 23 having the largest cross-sectional area It consists of the two-step cross-sectional area change of the nozzle part 25 of the smallest area. Further, the opening 24 is provided between the connection end 16 and the cylindrical portion 23 having the largest area in order to flow mainly the flow of the exhaust gas flow other than the central portion to the outside of the acceleration portion.

  In the case of the apparatus 10 of Example 2, when the exhaust gas flow discharged from the connection end portion 16 flows into the cylindrical portion 23 having the largest cross-sectional area, the flow mainly in the central portion of the exhaust gas flow accelerates at once in the nozzle portion 25 The flow other than the central part is released from the opening 24 on the front side of the cylinder part 23 of the largest area, and is sucked into the strong negative pressure area V, and is accelerated and becomes a high speed flow and the central part downstream of the nozzle 25 It joins with the part flow. Also in Example 2, the distance from the tail pipe 28 is adjustable, and the range of the negative pressure region V can be changed. That is, the adjustment of the position of the tail pipe adjusts the degree of acceleration of the exhaust gas flow, and hence the magnitude of the negative pressure generated, as in Example 1 above.

  FIG. 8 shows an example 3 of the apparatus 10 for accelerating an exhaust gas flow according to the present invention, which also has the same basic configuration as the apparatus of Example 1. That is, the apparatus main body 20 having the connection end portion 16, the front surface portion 17, the cylindrical portion 18 and the rear surface portion 19, the exhaust gas flow acceleration cylinder 21 having the acceleration portion 22, the cylindrical portion 23, the opening 24 and the nozzle portion 25. And further has a configuration in which the tail pipe 28 is provided slidably on the pipe holding cylinder 29 in the front-rear direction. Therefore, the adjustment mechanism 40 will be described with reference to the description of Example 1 and the detailed description thereof will not be repeated.

  In the case of Example 3, the cylindrical portion 23 provided with the accelerating portion 22 is formed by cutting using an NC lathe or the like. The cylindrical portion 23 is attached to the support 26 using a bolt 23b, and therefore can be detached. Therefore, the acceleration unit 22 can be replaced according to the conditions such as the flow rate of the exhaust gas, whereby more appropriate acceleration of the exhaust gas flow is realized. Further, when the cylindrical portion 23 is cut out of the raw material, it is easy to select the length in the front-rear direction, and a more appropriate response can be made even in the manufacturing stage.

  In the acceleration device of Example 3, a hood 16a is provided so as to surround the connection end portion 16 so as to prevent the flow other than the central portion of the inflowing exhaust gas flow from being diffused to the outer periphery too much. Accordingly, the flow other than the central portion quickly becomes a suction flow to the negative pressure region V, and merges with the flow of the central portion downstream of the nozzle portion 25. Further, the adjustment of the position of the tail pipe can adjust the degree of acceleration of the exhaust gas flow, and hence the intensity of the negative pressure generated, as in the first embodiment.

  Further, with reference to FIG. 9, an example 4 of the exhaust gas flow acceleration device 10 according to the present invention will be described. The apparatus 10 of Example 4 is substantially the same as the apparatus of Example 1 in terms of the basic configuration. Therefore, the apparatus main body 20 having the connection end 16, the front surface 17, the cylindrical portion 18 and the rear surface 19, and the exhaust gas flow acceleration cylinder 21 having the acceleration portion 22, the cylindrical portion 23, the opening 24 and the nozzle portion 25. And further has a configuration in which the tail pipe 28 is provided slidably on the pipe holding cylinder 29 in the front-rear direction. Therefore, the description of Example 1 is used for these, and the detailed description will not be repeated, and the description will be made centering on the adjusting mechanism 40.

  In the adjusting mechanism 40 of Example 4, the tail pipe 28 is slidably attached to the apparatus main body 20 and is automatically provided movably, and the negative pressure generated by the exhaust gas flow accelerating cylinder 21 is strong. It has a negative pressure sensitive portion 34 configured to be movable according to the distance. The negative pressure sensing unit 34 is attracted to the negative pressure generated downstream of the exhaust gas flow accelerating cylinder 21, and the exhaust gas flow flowing outside the exhaust gas flow accelerating cylinder 21 collides with the negative pressure sensitive unit 34. A ring-shaped pressure receiving portion is provided at the front end portion of the tail pipe 28.

  The negative pressure sensitive portion 34 formed of a ring-shaped pressure receiving portion is in contact with the acceleration portion 22 of the exhaust gas flow acceleration cylinder 21 when the internal combustion engine 11 is not operated. For this purpose, an extension 35 is provided in front of the tail pipe 28, and a plurality of openings 36 for negative pressure suction are formed there. Reference numeral 37 denotes biasing means, which biases the tail pipe 28 to the initial position, one end of which is connected to the apparatus body 20 side, and the other end of which is connected to the tail pipe 28 side. For example, the cases 37a and 37b are combined in a so-called telescopic (slidable back and forth), and are formed by incorporating a compression spring therein. Reference numerals 38 and 39 denote mounting portions of the biasing means 37. The pressure receiving portion 34 has a gap that allows it to slide with the inner circumferential surface of the cylindrical portion 18 (see FIG. 3B).

  In the exhaust gas flow acceleration device 10 according to the present invention provided with the adjustment mechanism 40 of Example 4, the flow E1 mainly in the central part of the exhaust gas flow passes through the tapered cylindrical acceleration portion 22 and is accelerated at high speed. It becomes a flow. Then, along with acceleration, a strong negative pressure region V is formed in the region shown by the oblique lines in FIG. 4 between the nozzle portion 25 and the tail pipe 28 in the periphery thereof. There is no change in that the flow E2 other than the central part flows out of the acceleration part 22 mainly.

  However, a strong negative pressure due to the flow in the central portion acts on the rear surface of the ring-shaped negative pressure sensitive portion 34 and pulls the tail pipe 28 backward, and at the same time, the exhaust gas flow flowing around the exhaust gas flow acceleration cylinder 21 is the front Collide with and push backward. In response to the pressure change generated in this manner, the tail pipe 28 moves rearward, so that the space between the exhaust gas flow accelerating cylinder 21 and the tail pipe 28 opens to produce a flow from the outer periphery toward the center. This flow is drawn into the above-mentioned strong negative pressure region V to become a suction flow, and joins the central flow at high speed as in the case of Example 1 and is released to the atmosphere. Since the back and forth movement of the tail pipe 28 automatically changes in accordance with the pressure change, the speed change, etc. occurring in the exhaust gas flow, the optimum exhaust gas flow acceleration can be obtained according to the operating state of the internal combustion engine.

  Further, with reference to FIG. 10, an example 5 of the exhaust gas flow acceleration device 10 according to the present invention will be described. The apparatus 10 of Example 5 is not substantially the same as the apparatuses of Examples 1 to 4 in terms of the basic configuration. However, in order to detect the state of the exhaust gas flow, the device 10 of Example 5 is provided with the sensor 41 installed at an arbitrary position of the exhaust pipe from the combustion chamber exhaust port, and the control unit 42 which outputs the movement amount according to the sensor signal. And an electronic control unit configured to include a motor 43 that operates according to the output and a moving mechanism 44 that moves the tail pipe 28 by the motor 43. As the state of the exhaust gas flow, the speed, pressure, flow rate, temperature and the like are to be detected.

  In the apparatus 10 of Example 5, the flow rate and flow rate of the exhaust gas flow, which change with the load and rotational speed during operation of the internal combustion engine, are detected by the sensor 41, and the control unit 42 performs calculation using the sensor signal as one parameter. The calculation result is output to a motor 43 composed of a servomotor or the like, and the tail pipe 28 is moved back and forth by the moving mechanism 44 to adjust the degree of acceleration of the exhaust gas flow. According to the configuration of Example 5, since the mechanical configuration of Example 4 can be replaced with the electronic configuration, either mechanical or electronic can be selected according to the application target.

  As described above, according to the exhaust gas flow acceleration device 10 of the first embodiment, the degree of acceleration of the exhaust gas flow can be appropriately adjusted in accordance with the operating environment, the displacement, etc. of the internal combustion engine. In the practice of the present invention, since it is important to apply the acceleration device 10 corresponding to the conditions such as the displacement, devices of different sizes are prepared. The apparatus for accelerating an exhaust gas flow according to the present invention can be applied to an internal combustion engine for a vehicle represented by the above-described gasoline engine or diesel engine, but the object is not limited to these, and the inside of the engine The present invention can be applied to any internal combustion engine in which the exhaust gas produced by the combustion of fuel at this stage acts as a thermodynamic fluid, and is also applicable to, for example, a gas turbine engine or the like.

Second Embodiment
Hereinafter, a second embodiment of the present invention will be described with reference to the illustrated embodiment. In the second embodiment, a cap and a silencer are added to the configuration of the exhaust gas flow acceleration device 10 according to the first embodiment. The basic configuration of the acceleration device 10 excluding the cap and the muffling device is the same as that of the first embodiment, so the configuration of the acceleration device 10 excluding the cap and the muffling device is the same as the device of Example 1 The code | symbol is used and detailed description is abbreviate | omitted. Further, in the second embodiment, although a configuration in which a cap and a silencer are added to the configuration of the acceleration device 10 of Example 1 is described, a cap and a silencer are added to the configuration of the acceleration device 10 in Examples 2 to 5 It may be a configuration.

  The exhaust gas flow acceleration device 10 according to the second embodiment, as shown in FIG. 11, is provided at a device body 20 having a hollow cylindrical structure, and at one end located upstream of the exhaust gas flow. A silencer 60, which is one of the silencers, is provided between the connecting end 16 and the other end. Further, on the outer periphery of the tail pipe 28, an annular impact sound absorbing device 70, which is one of the muffling devices, is provided. Further, on the outlet side (exhaust gas outflow side) of the tail pipe 28, a cap 50 for changing the outflow direction of the exhaust gas flow is attached.

  The cap 50 is formed in a hollow cylindrical structure, and the bent portion 51 is formed on the tip end side (exhaust gas outflow side) of the cap 50, thereby changing the outflow direction of the exhaust gas flow inflowing through the tail pipe 28 Let Specifically, the exhaust gas flow passes through the cap 50, and the outflow direction is displaced by the displacement angle D from the axial direction of the tail pipe 28 (the direction shown by the dotted line in FIG. 11) (FIG. 11) In the direction indicated by the arrow A). The displacement angle D can be arbitrarily set by changing the bending rate of the bending portion 51 to be formed. Further, since the cap 50 can be mounted by being rotated about the axial direction of the tail pipe 28, the outflow direction of the exhaust gas can be freely controlled. For example, when the cap 50 is attached by rotating it 180 degrees from the attachment position shown in FIG. 11, the outflow direction of the exhaust gas can be changed from the lower left direction to the upper left direction.

  By the way, since the acceleration device 10 of the present invention can be attached to various devices provided with an internal combustion engine, it is assumed that it can be attached in various postures, and it is necessary to control the exhaust gas discharge direction according to the posture. is there. On the other hand, in the acceleration device 10 according to the second embodiment, since the cap 50 which can be attached by being rotated about the axial direction of the tail pipe 28 is provided, the exhaust gas according to the mounting posture of the acceleration device 10 Can control the discharge direction of the Therefore, the acceleration device 10 according to the second embodiment can be suitably mounted on various devices provided with an internal combustion engine, and has flexibility or flexibility.

  Any method may be used to attach the cap 50 rotatably to the tail pipe 28. However, once the attachment angle is determined and attached, the cap 50 is fixed so as not to be pivoted by the exhaust gas flow. Is preferred. For example, at the connection position of the cap 50 to the tail pipe 28, a plurality of screw holes are formed annularly at predetermined angles (for example, 15 degrees), and the position of the screw holes as a whole is By not changing, the cap 50 may be fixed to the tail pipe 28 via a screw even when the cap 50 is rotated.

  The silencer 60 has a hollow cylindrical structure, and a plurality of muffling structures 61 are provided in its inner space as a barrier. The plurality of muffling structures 61 are each formed of a sound absorbing material (for example, glass wool, steel wool, steel mesh, etc.), and the internal space of the silencer 60 is divided into a plurality of spaces. As described above, by providing the muffling structure 61 in the inner space of the muffler 60, the exhaust gas flow passes through a complicated path when passing through the inner space of the muffler 60, and Repeating pressure interference will reduce the volume.

  The silencer 60 is replaceably attached to the apparatus main body 20 by the cartridge attachment part 62 (see FIG. 12A). Thus, for example, when replacing the silencer 60 according to the change of the displacement, it is possible to flexibly cope with replacing only the silencer 60 instead of the entire acceleration device 10. Therefore, it is possible to configure the acceleration device 10 that can flexibly cope with internal combustion engines such as diesel, gasoline light oil, heavy oil engines and the like.

  In addition, since the silencer 60 is provided on the upstream side of the exhaust gas flow of the apparatus main body 20 and integrally configured as the acceleration device 10, there is no need to provide a silencer separately from the acceleration device 10, and the entire device becomes compact. . Therefore, even if the accelerator device 10 according to the second embodiment is attached to various devices provided with an internal combustion engine in various postures, compact attachment is possible. Therefore, the acceleration device 10 according to the second embodiment can be suitably mounted on various devices provided with an internal combustion engine, and has flexibility or flexibility.

  The impact sound absorbing device 70 is annularly formed on the outer periphery of the tail pipe 28, and a plurality of sound absorbing tubes 71 are annularly arranged in the annular portion (see FIG. 12B). The plurality of sound absorption pipes 71 are respectively opened to an exhaust gas ejection area RA from which the exhaust gas flow accelerated by the exhaust gas flow acceleration cylinder 21 flows out. As described above, by forming the plurality of sound absorbing pipes 71 in the impact sound absorbing device 70, the impact sound generated as the exhaust gas flow is accelerated is reduced. Hereinafter, this principle will be described with reference to FIG.

  As shown in FIG. 13, when a sound wave from the exhaust gas injection area RA is incident on the sound absorption pipe 71 whose one end is open to the exhaust gas injection area RA and the other end is closed, a reflected wave is reflected at the closed end. It occurs. For example, when the length of the sound absorbing tube 71 is 1⁄4 of the wavelength, a resonance phenomenon occurs, and the incident wave (solid line in the figure) and the reflected wave (dotted line in the figure) near the opened end are in antiphase and cancel each other. By matching, the reduction effect can be obtained. Although only a specific frequency can be reduced in the single sound absorption tube 71, sound waves with a relatively wide range of frequencies can be reduced by combining the sound absorption tubes 71 of various lengths. Therefore, for example, the impact sound reduction effect of the impact sound absorbing device 70 can be enhanced by changing the lengths of the plurality of sound absorbing pipes 71, respectively.

  In addition, although the above-mentioned impact sound absorption apparatus 70 utilizes the resonance phenomenon by the sound absorption pipe 71, it is not restricted to this. For example, by expanding or contracting a part of the flow path from which the accelerated exhaust gas flow flows out to change the impedance of the sound wave to generate a reflected wave, and by interfering with the reflected wave, the energy of the sound is reduced. It may be.

  As described above, according to the acceleration device 10 of the second embodiment, since the shock noise absorbing device 70 is provided, the shock noise generated as the exhaust gas flow is accelerated is reduced. Therefore, the acceleration device 10 according to the second embodiment can be suitably mounted on various devices provided with an internal combustion engine, and has flexibility or flexibility.

DESCRIPTION OF SYMBOLS 10 Accelerator of exhaust gas flow 11 Internal combustion engine 13 Exhaust pipe 16 Connection end part 17 Front part 18 Tubular part 19 Back surface part 20 Device main body 21 Exhaust gas flow acceleration cylinder 22 Acceleration part 23 Tubular part 24 and 36 Opening part 25 Nozzle part Reference Signs List 26 support 27 exhaust gas suction port 28 tail pipe 29 pipe holding cylinder 30, 40 adjustment mechanism 33 adjustment hole 34 negative pressure sensing part 35 extension part 37 biasing means 38, 39 mounting part 41 sensor 42 control part 43 motor 44 moving mechanism DESCRIPTION OF SYMBOLS 50 Cap 51 bending part 60 silencer 61 muffling structure 62 cartridge type attachment part 70 impact sound absorption apparatus 71 sound absorption pipe

Claims (2)

An acceleration device installed at an end of an exhaust system of an internal combustion engine to accelerate an exhaust gas flow and release it to the atmosphere,
An apparatus main body having a cylindrical structure as a whole, wherein one end is an exhaust gas inflow side receiving the exhaust gas flow discharged from the end of the exhaust system and the other end is an exhaust gas outflow side discharging the exhaust gas flow to the atmosphere;
And a silencer provided on the exhaust gas inflow side of the apparatus main body to reduce noise associated with the atmospheric release of the exhaust gas flow.
An exhaust gas flow accelerator characterized in that. An acceleration device installed at an end of an exhaust system of an internal combustion engine to accelerate an exhaust gas flow and release it to the atmosphere,
An apparatus main body having a cylindrical structure as a whole, wherein one end is an exhaust gas inflow side receiving the exhaust gas flow discharged from the end of the exhaust system and the other end is an exhaust gas outflow side discharging the exhaust gas flow to the atmosphere;
A tail pipe provided on an exhaust gas outflow side of the apparatus main body to release the exhaust gas flow to the atmosphere;
And an annular impact sound absorbing device provided on an outer periphery of the tail pipe to reduce noise associated with the atmospheric discharge of the exhaust gas flow,
The impact sound absorbing device has a plurality of sound absorbing tubes arranged in an annular shape,
Each of the plurality of sound absorbing tubes is open to an exhaust gas discharge area from which the accelerated exhaust gas flow flows out.
An exhaust gas flow accelerator characterized in that.

Images