JP2017227173A - Exhaust gas flow acceleration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly adjust an acceleration degree of an exhaust gas flow according to an operation environment, an exhaust amount and the like of an internal combustion engine.SOLUTION: An exhaust gas flow acceleration device is composed of a device body 20 having a cylindrical structure as a whole, in which one end is applied as an exhaust gas inflow side for receiving an exhaust gas flow discharged from a terminal end of an exhaust system, and the other end is an exhaust gas outflow side for releasing an exhaust gas to atmospheric air, an exhaust gas flow acceleration cylinder 21 having a cylindrical accelerating portion disposed to accelerate mainly the flow at a central portion of the exhaust gas flow, and an opening portion disposed for allowing mainly the flow excluding that at the central portion, of the exhaust gas flow to flow to the external of the accelerating portion, a tale pipe 28 discharged at the exhaust gas outflow side to release the exhaust gas flow accelerated in the exhaust gas flow acceleration cylinder to the atmospheric air, and an adjustment mechanism 30 capable of moving the tale pipe in a longitudinal direction with respect to the device body to adjust an interval between the exhaust gas flow acceleration cylinder and the tale pipe.SELECTED DRAWING: Figure 2

Description

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

  In an internal combustion engine represented by an automobile engine, an exhaust system not only releases exhaust gas generated by combustion to the atmosphere but also plays an important role in adjusting exhaust gas components and reducing exhaust noise. In particular, with the progress of legal development related to exhaust gas purification in recent years, the exhaust system has become more complicated and the back pressure tends to increase. In order to improve the above-mentioned tendency, the inventor of the present case has been working on a technique for speeding up exhaust gas and releasing it to the atmosphere, and has applied for a patent for a part of the results and tried to disclose the technique.

  Among them, Japanese Patent Laid-Open No. 6-173634 is an invention in which scavenging is promoted by providing a bypass path in the exhaust system to increase the exhaust gas flow rate and reducing the back pressure, and Japanese Patent Laid-Open No. 7-233722 is exhausted to the exhaust pipe. Japanese Patent Laid-Open No. 8-326547, which is provided with a pipe flow pipe for taking out gas and making it flow, solves the problem of heat damage, has two acceleration stages for accelerating the exhaust gas flow and generating negative pressure It is an invention that generates a high level of negative pressure suction energy. Japanese Patent Laid-Open No. 9-170432 is an invention in which a throttle portion for restricting the flow rate of the exhaust gas flow is provided when exhaust gas is discharged into the atmosphere at high speed, and Japanese Patent Laid-Open No. 10-331631 is an engine. Japanese Patent Laid-Open No. 2001-98924 is an invention that aims to reduce the size of a muffler having an early acceleration effect.

  In the process of continuing development, the results did not match the objectives, and the results were not always as intended, but the issues to be solved have become increasingly clear. A typical example is flexibility corresponding to changes in engine displacement, for example. If this is not sufficient, various types of products must be prepared depending on the amount of displacement. Another problem is the downsizing of the device. The larger the size, the harder it is to attach to the automobile, and the greater the load on the exhaust pipe. Through this process, the inventor of the present case has obtained a technique for solving the above-mentioned problems, incorporated this technique into an actual device, and as a result, the invention of Japanese Patent Application Laid-Open No. 2011-153574 has been reached. is there.

  A system composed of such a series of inventions is called JVCS (registered trademark), and has gained a certain level of evaluation up to now and has been a successful product. However, this system has a side where technical elucidation is not necessarily progressing though a remarkable effect is actually obtained. For this reason, in order to obtain the optimum result by actually applying the device to each engine, it is necessary to rely on a skilled engineer having appropriate experience and technology, and therefore it cannot be installed by anyone. Therefore, the present inventor has continued the development aiming at an exhaust gas flow accelerating device that 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 A JP 2001-98924 A JP 2011-153574 A

  The present invention has been made in view of the above points, and an object of the present invention is to appropriately adjust the acceleration degree of the exhaust gas flow in accordance with the operating environment of the internal combustion engine, the exhaust amount, and the like. Another object of the present invention is to provide an exhaust gas flow accelerating device that can be appropriately installed even if it is not necessarily a skilled engineer.

  In order to solve the above-described problems, the present invention provides an apparatus for accelerating an exhaust gas flow and releasing it to the atmosphere at one end of an exhaust system of an internal combustion engine. The exhaust gas inflow side for receiving the exhaust gas, and the other end is the exhaust gas outflow side from which the exhaust gas is released to the atmosphere. Exhaust gas having a cylindrical acceleration portion provided for accelerating the flow in the central portion and an opening portion provided for flowing a flow other than mainly the central portion of the exhaust gas flow outside the acceleration portion A flow accelerating cylinder, a tail pipe provided on the exhaust gas outflow side to release the exhaust gas flow accelerated by the exhaust gas accelerating cylinder, and the tail pipe moved in the front-rear direction with respect to the apparatus main body. Made it possible Thus it is obtained taking steps that constitute a regulatory mechanism allowing adjusting the spacing between the exhaust gas acceleration tube and the tail pipe.

  As described above, the system to which the present invention belongs can not be said to be technically elucidated despite the fact that a remarkable effect is actually obtained. However, the element that is accelerated by the passage of the acceleration cylinder provided inside the acceleration device, the element that passes outside the acceleration cylinder, and the element that the above two elements merge downstream of the acceleration section are released into the atmosphere. It is involved in the acceleration of gas flow, and it has been found that the acceleration result depends on the apportionment of these factors.

  Therefore, the present invention is configured so that the degree to which these elements contribute can be adjusted more easily, and is intended to contribute to solving the problems of the invention. In the present invention, the exhaust gas flow accelerating cylinder having the acceleration portion and the opening provided in the apparatus main body, the tail pipe and the adjusting mechanism are particularly important constituent elements. The exhaust gas flow expands once it flows into the device main body from the end of the exhaust system, and is divided into a central flow and other flows, and the accelerating portion mainly accelerates the central flow to generate negative pressure. The flow other than is sucked to the negative pressure at the opening and accelerated. In general, it can be said that the nozzle diameter of the accelerating portion has a cross-sectional area smaller than the cross-sectional area of the end of the exhaust system. In addition to the conventionally employed tapered shape in which the cross-sectional area changes continuously, a form in which the cross-sectional area changes stepwise (discontinuously) can also be selected.

  The adjusting mechanism enables the tail pipe to move in the front-rear direction with respect to the apparatus main body, thereby adjusting the distance between the exhaust gas accelerating cylinder and the tail pipe. With this configuration requirement, there is a change in the volume from the merging portion to the tail pipe end at the portion where the element accelerated by the passage of the accelerating cylinder and the element passing through the outside of the accelerating cylinder merge downstream of the accelerating section. It becomes easy.

  As an adjustment mechanism that makes it possible to adjust the distance between the exhaust gas flow accelerating cylinder and the tail pipe, the tail pipe is slidably mounted on the apparatus body and is movably provided by manual operation. It is provided so as to be fixed at the moving position. This is a preferable form as an example in which the adjustment mechanism is configured manually.

  The tail pipe is slidably attached to the main body of the device as an adjustment mechanism that allows the distance between the exhaust gas flow acceleration cylinder and the tail pipe to be adjusted. In response to this, it has a negative pressure sensitive part configured to be automatically movable. This is a preferable form as an example in which the adjusting mechanism is configured automatically.

  Also, the tail pipe has a negative pressure sensitive portion at the front end portion that is sucked by the negative pressure generated downstream of the exhaust gas flow acceleration cylinder and collides with the exhaust gas flow flowing outside the exhaust gas flow acceleration cylinder. Also good. By receiving the pressure of the exhaust gas flow, the pressure receiving portion moves backward in a direction that widens the interval between the acceleration cylinder and the tail pipe.

  As an adjustment mechanism that makes it possible to adjust the distance between the exhaust gas flow accelerating cylinder and the tail pipe, a sensor that detects the state of the exhaust gas flow, a control unit that outputs a movement amount according to the sensor signal, and a mechanism that operates according to the above output A configuration including a motor and a moving mechanism for moving the tail pipe by the motor is preferable in the present invention. In the present invention, “negative pressure” means a pressure lower than a reference pressure. For example, the pressure of an exhaust gas flow flowing through the exhaust system is a reference pressure.

  Since the present invention is configured and operates as described above, there is an effect that the acceleration degree of the exhaust gas flow can be appropriately adjusted according to the operating environment of the internal combustion engine, the exhaust amount, and the like. . Further, according to the present invention, the tail pipe can be moved in the front-rear direction with respect to the apparatus main body, and the distance from the exhaust gas flow accelerating cylinder can be adjusted, so that it is extremely easy to cope with conditions such as engine displacement. Thus, it is possible to provide an exhaust gas flow accelerating device that can be appropriately mounted even by a skilled engineer.

It is explanatory drawing which shows the state installed in the terminal of the exhaust system of an internal combustion engine as an example of the acceleration apparatus of the exhaust gas flow which concerns on this invention. It is longitudinal cross-sectional explanatory drawing which shows the internal structure of Example 1 of an apparatus same as the above. The cross section of the apparatus same as the above is shown, and A is a sectional view taken along the line IIIA-IIIA in FIG. 2, and B is a sectional view taken along the line IIIB-IIIB in FIG. It is a longitudinal cross-sectional view explaining the effect | action in the acceleration apparatus of the exhaust gas flow of the said Example 1 which concerns on this invention. FIG. 5 shows an example 2 of an apparatus applied to FIG. 1, in which A is a longitudinal sectional explanatory view, and B is a sectional view taken along the line VB-VB in FIG. 5A. FIG. 7 shows an example 3 of the apparatus applied to FIG. 1, wherein A is a longitudinal sectional explanatory view, and B is a VIB-VIB sectional view longitudinal sectional explanatory view in FIG. 6A. FIG. 6 is a longitudinal cross-sectional explanatory view showing Example 4 of the device applied to FIG. 1. It is explanatory drawing which shows Example 5 of an apparatus same as the above.

  Hereinafter, the present invention will be described in more detail with reference to illustrated embodiments. FIG. 1 relates to an example 1 of an exhaust gas flow acceleration device 10 according to the present invention. 11 is an internal combustion engine, 12 is a combustion chamber, 13 is an exhaust pipe for discharging generated exhaust gas, and 14 is exhaust gas purification. FIG. 1 shows a catalyst device for the exhaust pipe 13. The exhaust pipe 13 is equipped with a muffler 15, and the catalyst device 14, the exhaust pipe 13 including the muffler 15, and the like constitute an exhaust system.

  In the present embodiment, a 4-cycle gasoline engine is assumed as the internal combustion engine 11, and the exhaust gas flow acceleration device 10 is installed at the exhaust pipe 13, that is, at the end of the exhaust system. As shown in detail in FIG. 2, the exhaust gas flow acceleration device 10 according to the present invention includes a device main body 20 having a hollow cylindrical structure, and the device main body 20 is located upstream of the exhaust gas flow. Is connected to the end of the exhaust pipe 13 in an airtight manner at a connection end 16 provided at one end located at the end.

  The acceleration device 10 of the present invention includes an apparatus main body 20 having the connection end 16 at one end as an exhaust gas inflow side for receiving an exhaust gas flow discharged from the end of the exhaust system, and the other end releasing the exhaust gas to the atmosphere. This is the exhaust gas outflow side. What constitutes 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 tubular portion 18 and a rear surface portion 19 on the exhaust gas outflow side. Yes.

  The connection end portion 16 is inserted into a connection hole 17a formed in the front surface portion 17 of the apparatus main body 20, and is joined by welding. The connection hole 17a is provided substantially concentrically with the apparatus main body 20 (see FIG. 3A). The joining means may be performed only by welding, and screw connection or a combination thereof is also possible. Such an apparatus main body 20 is manufactured using an refractory 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 accelerating cylinder 21 is provided inside the apparatus main body 20. The exhaust gas flow accelerating cylinder 21 is provided to accelerate mainly the flow in 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 concentrically with the apparatus main body 20. The exhaust gas flow accelerating cylinder 21 in the present invention is formed so as to have a relatively large volume in comparison with the conventional exhaust gas flow accelerator, and receives a larger amount of exhaust gas discharged from the exhaust system. It is configured to be able to.

  The exhaust gas flow accelerating cylinder 21 includes a tapered cylindrical acceleration part 22 and an opening 24 provided in the cylinder part 23 in order to flow a flow other than mainly the central part of the exhaust gas flow outside the acceleration part. have. The cylinder part 23 shown as Example 1 is substantially cylindrical. The relatively large volume mentioned above is a volume related to the tapered cylindrical accelerating portion 22. For example, the volume of the tapered portion is increased by making the inclined angle with respect to the central axis more prominent. Can be increased. In the case of the embodiment, the volume of the exhaust gas flow accelerating cylinder 21 is set to about twice that of the second accelerating portion in the invention of Japanese Patent Application Laid-Open No. 2011-153574, for example. According to the experiment, the optimal volume increase was about 100% increase compared to the conventional volume, but the effect started to appear at 20% increase and reached 150% even when it exceeded 150%. It is considered that good results can be obtained.

  In the inventor's invention listed as the prior art, the tapered shape of the accelerating cylinder is set to a sharper angle with a sharp inclination angle with respect to the central axis. On the other hand, the resistance tends to increase by setting the inclination angle to be more standing as in the present invention, but the speed of the compressible exhaust gas flow increases to the critical angle, and accordingly, the flow to the opening 24 is increased. The detour flow increases. Therefore, by appropriately setting the critical angle, the acceleration in the acceleration unit 22 reaches the maximum without adversely affecting the acceleration of the exhaust gas flow, and the pressure drop generated downstream of the acceleration unit 22 is also maximized. The critical angle C has conventionally been less than 30 degrees with respect to the central axis, but in the case of the present invention, it has been confirmed by experiments that it is suitable in the range of 30 to 45 degrees.

  Although the opening part 24 is also provided in said cylinder part 23, the opening part 24 has an elongate form in the central-axis direction, and several pieces are opened in the circumferential direction of the cylinder part 23 at equal intervals. The area of the openings 24 is also an important factor. In comparison with the opening area of the nozzle part 25 of the exhaust gas flow accelerating cylinder 21, the area of the opening part 24 is preferably about several times the opening area of the nozzle part 25. In the embodiment, the area of the opening 24 is set to four times the opening area of the nozzle part 25, and good results are obtained. In the illustrated embodiment, the comparison with the cross-sectional area S0 at the end of the exhaust system is as follows: S0> cross-sectional area of the opening S1 + cross-sectional area S2 of the rear end nozzle, that is, the gas flow at the end of the exhaust system is caused by the accelerator 10 of the present invention. The cross-sectional area is narrowed down.

  The exhaust gas flow accelerating cylinder 21 is fixed to the cylindrical part 18 by means such as welding in a cylindrical part 23 at several places using a support 26. 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 running vibration. Functions as a support. The space between the supports 26 is an exhaust gas suction port 27 through which an external exhaust gas flow passes, and communicates with the negative pressure space formed behind the acceleration unit 22 through the periphery thereof.

  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 20 to the atmosphere. The tail pipe 28 is provided in the pipe holding cylinder 29 so as to be slidable in the front-rear direction. For this purpose, a mounting hole 19a is provided substantially concentrically in the rear surface portion 19, and a pipe holding cylinder 29 is inserted therein and joined by means such as welding. The pipe connection cylinder 29 is arranged in a positional relationship such that the front end portion overlaps or does not overlap the rear end portion of the exhaust gas flow acceleration cylinder 21.

  An adjusting mechanism 30 is provided to enable the tail pipe 28 to move in the front-rear direction with respect to the apparatus main body 20 and thereby to adjust the distance between the exhaust gas flow accelerating cylinder 21 and the tail pipe 28. . The adjusting mechanism 30 shown in FIG. 2 has an internal thread portion 31 formed in the pipe holding cylinder 29, an external thread body 32 screwed into the internal thread portion 31, and an adjustment hole provided at a plurality of positions as positioning portions in the front-rear direction of the tail pipe 28. 33. Accordingly, the position of the tail pipe 28 in the front-rear direction can be fixed by aligning the male screw body 32 with 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 accelerating cylinder 21 and is mainly in the central portion of the exhaust gas flow. The flow E1 passes through the tapered cylindrical acceleration portion 22 and is accelerated to become a high-speed flow. Along with the acceleration, a strong negative pressure region V is formed in the region indicated by the umbilical line in FIG. 4 between the downstream of the nozzle portion 25 and the surrounding tail pipe 28. In the exhaust gas flow accelerating cylinder 21, the flow E2 other than the central portion mainly flows out of the accelerating portion 22, but this flow is sucked into the strong negative pressure region V to become the suction flow E3, and at a high speed at the central portion. The flow E1 merges and is released into the atmosphere as E4.

  Although the periphery of the nozzle portion 25 is shown as the negative pressure region V, the strongest negative pressure is generated in the high-speed flow E1 passing through the nozzle portion 25, and the negative pressure region V indicates the outer edge of the negative pressure. is there. In particular, the exhaust gas flow acceleration device 10 according to the present invention has a configuration in which the adjustment mechanism 30 is operated so that the tail pipe 28 can be moved in the front-rear direction with respect to the device main body 20. Therefore, by adjusting the distance between the exhaust gas flow acceleration 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 chain double-dashed line shown in FIG. 4 indicates a state in which the tail pipe 28 is most retracted. In this state, the negative pressure region V is expanded to the maximum, generating a stronger negative pressure and The maximum acceleration is set.

  Furthermore, Example 2 of the exhaust gas flow accelerating device 10 according to the present invention will be described with reference to FIG. Since the basic configuration of the apparatus 10 of Example 2 is not substantially different from that of the apparatus of Example 1, reference numerals are used and detailed description thereof is omitted. Unlike the case of Example 1 in which the cross-sectional area continuously changes, the acceleration device 10 of Example 2 changes the cross-sectional area stepwise (discontinuously). It consists of a two-stage change in the cross-sectional area of the nozzle portion 25 with the smallest area. In addition, the opening 24 is provided between the connection end 16 and the cylindrical portion 23 having the maximum area in order to flow the exhaust gas flow mainly outside 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 at the center of the exhaust gas flow is accelerated at a stroke in the nozzle portion 25. Then, the flow other than the central portion escapes from the opening 24 on the front side of the cylindrical portion 23 having the largest area, and is sucked into the strong negative pressure region V and accelerated to become a high-speed flow at the center downstream of the nozzle portion 25. Merge with the flow of the part. Also in Example 2, the distance from the tail pipe 28 can be adjusted, and the range of the negative pressure region V can be changed. That is, the adjustment of the tail pipe position and the degree of acceleration of the exhaust gas flow, and hence the strength of the generated negative pressure, are the same as in Example 1.

  FIG. 6 shows Example 3 of the exhaust gas flow accelerating device 10 according to the present invention, and this is also the same as the device of Example 1 in terms of basic configuration. 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, and the exhaust gas flow acceleration cylinder 21 having the acceleration portion 22, the cylinder portion 23, the opening portion 24, and the nozzle portion 25. And a configuration in which the tail pipe 28 is provided on the pipe holding cylinder 29 so as to be slidable in the front-rear direction. Accordingly, the adjustment mechanism 40 will be described without reiterating the detailed description by using the description of Example 1 for these.

  In the case of Example 3, the cylinder part 23 provided with the acceleration part 22 is formed by cutting using NC lathe etc. The cylindrical portion 23 is attached to the support body 26 using the bolts 23b, and therefore can be attached and detached. For this reason, the acceleration part 22 can be replaced | exchanged according to conditions, such as the flow volume of exhaust gas, and the more suitable acceleration of exhaust gas flow is implement | achieved by this. Further, when the cylindrical portion 23 is cut out from the raw material, it is easy to select the length in the front-rear direction, and a more appropriate response can be made at the manufacturing stage.

  In the acceleration device of Example 3, a hood 16a is provided so as to surround the connection end portion 16, and a flow other than the central portion of the inflowing exhaust gas flow is configured not to diffuse excessively to the outer periphery. Therefore, the flow other than the central portion quickly becomes a suction flow into the negative pressure region V, and merges with the flow in the central portion downstream of the nozzle portion 25. Further, as in the case of Example 1, it is possible to adjust the degree of acceleration of the exhaust gas flow, and hence the strength of the generated negative pressure, by adjusting the tail pipe position.

  Furthermore, Example 4 of the exhaust gas flow accelerating device 10 according to the present invention will be described with reference to FIG. The apparatus 10 of Example 4 is not substantially different from the apparatus of Example 1 with respect to the basic configuration. Therefore, the apparatus main body 20 having the connecting cylinder 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 cylinder portion 23, the opening portion 24, and the nozzle portion 25. And a configuration in which the tail pipe 28 is provided on the pipe holding cylinder 29 so as to be slidable in the front-rear direction. Therefore, the description of Example 1 is used for these, and the detailed description is not repeated, and the adjustment mechanism 40 will be mainly described.

  In the adjusting mechanism 40 of Example 4, the tail pipe 28 is slidably attached to the apparatus main body 20 and is automatically movably provided, and the strong negative pressure generated in the exhaust gas flow accelerating cylinder 21 is provided. It has the negative pressure sensitive part 34 comprised so that it can move according to this. The negative pressure sensitive part 34 is sucked by 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 part 34. A ring-shaped pressure receiving portion is provided at the front end portion of the tail pipe 28.

  The negative pressure sensing part 34 formed of a ring-shaped pressure receiving part is in a position in contact with the acceleration part 22 of the exhaust gas flow accelerating cylinder 21 when the internal combustion engine 11 is not operated. Therefore, an extension 35 is provided in front of the tail pipe 28, and a plurality of openings 36 for suctioning negative pressure are formed there. Reference numeral 37 denotes urging means for urging the tail pipe 28 to the initial position, one end of which is connected to the apparatus main body 20 side and the other end is connected to the tail pipe 28 side. For example, the cases 37a and 37b are combined with a so-called telescopic (slidable back and forth), and have a built-in compression spring. Reference numerals 38 and 39 denote attachment portions of the urging means 37. In addition, the said pressure receiving part 34 has the clearance gap which is slidable between the internal peripheral surfaces of the cylindrical part 18 (refer FIG. 3B).

  In the exhaust gas flow accelerating device 10 according to the present invention including the adjusting mechanism 40 of Example 4, the flow E1 in the central portion of the exhaust gas flow passes through the tapered cylindrical acceleration portion 22 and is accelerated and accelerated. It becomes a flow. Along with the acceleration, a strong negative pressure region V is formed in the region shown by hatching in FIG. 4 between the downstream of the nozzle portion 25 and the surrounding tail pipe 28. In the exhaust gas flow accelerating cylinder 21, Mainly, the flow E2 other than the central part flows out of the acceleration part 22.

  However, the strong negative pressure generated by the flow at the center acts on the rear surface of the ring-shaped negative pressure sensing portion 34 to pull the tail pipe 28 rearward, and at the same time, the exhaust gas flow flowing around the outer periphery of the exhaust gas flow accelerating cylinder 21 Will hit and push backwards. In response to the pressure change thus generated, the tail pipe 28 moves rearward, the space between the exhaust gas flow accelerating cylinder 21 and the tail pipe 28 is opened, and a flow from the outer periphery toward the center is generated. This flow is sucked into the strong negative pressure region V to become a suction flow, and is merged with the flow in the central portion at a high speed and released into the atmosphere as in the case of Example 1. The back and forth movement of the tail pipe 28 is automatically changed in accordance with the pressure change, speed change, etc. generated in the exhaust gas flow, so that the optimum exhaust gas flow acceleration according to the operating state of the internal combustion engine can be obtained.

  Further, Example 5 of the exhaust gas flow accelerating device 10 according to the present invention will be described with reference to FIG. The basic configuration of the apparatus 10 of Example 5 is not substantially different from that of Examples 1 to 4. However, in order to detect the state of the exhaust gas flow, the apparatus 10 of Example 3 includes a sensor 41 installed at an arbitrary position of the exhaust pipe from the combustion chamber exhaust port, and a control unit 42 that outputs a movement amount according to the sensor signal. The electronic control device includes 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, 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 that varies depending on the load and the 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 such as a servo motor, and the tail pipe 28 is moved back and forth by the moving mechanism 44 to adjust the acceleration rate of the exhaust gas flow. According to the configuration of Example 5, since the mechanical configuration of Example 4 can be replaced with an electronic configuration, either mechanical or electronic can be selected according to the application target.

  As described above, according to the present invention, the acceleration degree of the exhaust gas flow can be appropriately adjusted according to the operating environment of the internal combustion engine, the exhaust amount, and the like. In implementing the present invention, it is important to apply the device 10 corresponding to the conditions such as the displacement, and therefore devices of different sizes are prepared. The exhaust gas flow accelerating device 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. The present invention can be applied to any internal combustion engine in which the exhaust gas generated by the combustion of the fuel works as a thermodynamic fluid. For example, it can also be applied to a gas turbine engine or the like.

DESCRIPTION OF SYMBOLS 10 Exhaust gas flow acceleration device 11 Internal combustion engine 13 Exhaust pipe 16 Connection end portion 17 Front surface portion 18 Tubular portion 19 Rear surface portion 20 Device body 21 Exhaust gas flow acceleration cylinder 22 Acceleration portion 23 Tube portion 24, 36 Opening portion 25 Nozzle portion 26 Support body 27 Exhaust gas suction port 28 Tail pipe 29 Pipe holding cylinder 30, 40 Adjustment mechanism 33 Adjustment hole 34 Negative pressure sensitive part 35 Extension part 37 Biasing means 38, 39 Mounting part 41 Sensor 42 Control part 43 Motor 44 Movement mechanism

Claims (6)

A device 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,
One end is an exhaust gas inflow side that receives an exhaust gas flow discharged from the end of the exhaust system, and the other end is an exhaust gas outflow side that releases the exhaust gas to the atmosphere, and the apparatus body having a generally cylindrical structure,
A cylindrical acceleration portion that is provided to accelerate mainly the flow in the central portion of the exhaust gas flow that flows in from the exhaust gas inflow side, and a flow other than the central portion of the exhaust gas flow that is mainly in the acceleration portion. An exhaust gas flow accelerating cylinder having an opening provided to flow outside;
A tail pipe provided on the exhaust gas outflow side in order to release the exhaust gas flow accelerated by the exhaust gas flow acceleration cylinder to the atmosphere;
Exhaust gas characterized in that the tail pipe can be moved in the front-rear direction with respect to the apparatus main body, and thereby has an adjustment mechanism that allows adjustment of the distance between the exhaust gas flow acceleration cylinder and the tail pipe. Gas flow accelerator. As an adjustment mechanism that makes it possible to adjust the distance between the exhaust gas flow accelerating cylinder and the tail pipe, the tail pipe is slidably mounted on the apparatus body and is movably provided by manual operation. 2. The exhaust gas flow acceleration device according to claim 1, wherein the exhaust gas flow acceleration device is fixed to the moving position. The tail pipe is slidably mounted on the main unit as an adjustment mechanism that allows the distance between the exhaust gas flow accelerating cylinder and the tail pipe to be adjusted, and also according to the negative pressure generated by the exhaust gas flow accelerating cylinder. The exhaust gas flow acceleration device according to claim 1, further comprising a negative pressure sensitive portion configured to be automatically movable. The tail pipe is sucked by a negative pressure generated downstream of the exhaust gas flow accelerating cylinder, and has a negative pressure sensitive portion at a front end portion where an exhaust gas flow flowing outside the exhaust gas flow accelerating cylinder collides. 3. The exhaust gas flow acceleration device according to 3. As an adjustment mechanism that makes it possible to adjust the distance between the exhaust gas flow accelerating cylinder and the tail pipe, a sensor that detects the state of the exhaust gas flow, a control unit that outputs a movement amount according to the sensor signal, and a mechanism that operates according to the above output The exhaust gas flow acceleration device according to claim 1 or 3, further comprising a motor and a moving mechanism for moving the tail pipe by the motor. The exhaust gas flow acceleration device according to any one of claims 1 to 5, wherein the acceleration section has a form in which a cross-sectional area changes stepwise (discontinuously).

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