JP3947047B2 - Exhaust duct and exhaust pipe device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of an exhaust pipe for guiding exhaust gas discharged from an internal combustion engine to a muffler.
[0002]
[Prior art]
Conventionally, an exhaust pipe device that guides exhaust gas discharged from a supercharger of an internal combustion engine to a muffler is known. This exhaust pipe device has a substantially U-turn shape due to the positional relationship between the exhaust gas supercharger outlet and the muffler inlet. This exhaust pipe device is composed of an exhaust duct on the supercharger side, an exhaust duct on the muffler side, and a straight pipe connecting the two exhaust ducts. The exhaust duct on the supercharger side has a structure in which a plurality of ring-shaped members obtained by obliquely cutting conical pipes and straight pipes are welded together to form a substantially U-turn shaped exhaust pipe device.
[0003]
[Problems to be solved by the invention]
In such a conventional exhaust pipe device, it is necessary to connect an exhaust duct bent from the exhaust side of the engine to the muffler. However, since the exhaust duct is difficult to be integrally formed, many members are connected. It is necessary to form together. In other words, a large number of special ring-shaped members obtained by obliquely cutting conical pipes and straight pipes are necessary, and there are no existing pipes or straight pipes to be used. It must be designed and manufactured in consideration of the condition. Furthermore, in order to weld the special ring-shaped members designed and manufactured in this way, accurate positioning is required. For this reason, it takes a lot of time to manufacture and assemble the pipe member constituting the exhaust duct, resulting in a problem that the productivity is low and the cost is high.
[0004]
An object of the present invention is to provide an exhaust duct and an exhaust pipe device that have a simple structure, high productivity, and low cost.
[0005]
[Means for Solving the Problems]
(1) The exhaust duct according to the invention of claim 1 is a duct main body having a single box structure in which a substantially folded passage portion is formed to connect the supercharger outlet to the muffler inlet, and the exhaust duct is discharged from the supercharger outlet. An inlet adapter disposed in the duct body for guiding the exhaust gas discharged to the duct body; and an exhaust adapter disposed in the duct body for guiding the exhaust gas discharged from the duct body to downstream equipment. And an outlet adapter having an exhaust path cross-sectional area larger than the path cross-sectional area.
(2) The invention of claim 2 is the exhaust duct of claim 1, wherein the exhaust adapter cross-sectional area of the inlet adapter is unchanged from the upstream end to the downstream end, and the exhaust adapter cross-sectional area of the outlet adapter is downstream from the upstream end. The duct body is characterized in that the cross-sectional area of the exhaust path gradually increases from the portion where the inlet adapter is connected to the portion where the outlet adapter is connected.
(3) The invention of claim 3 is an exhaust duct through which exhaust gas discharged from the supercharger outlet is guided, a straight pipe through which exhaust gas discharged from the exhaust duct is guided, and a connection for connecting the straight pipe and the muffler. In the exhaust pipe device including the duct, the exhaust duct is discharged from the supercharger outlet, and a duct body having a single box structure in which a substantially folded passage portion is formed to connect the supercharger outlet to the muffler inlet. An inlet adapter disposed in the duct body for guiding the exhaust gas discharged to the duct body, and an exhaust path of the inlet adapter disposed in the duct body for guiding the exhaust gas discharged from the duct body to downstream equipment And an outlet adapter having an exhaust path cross-sectional area larger than the cross-sectional area.
(4) In the exhaust pipe device according to claim 3, the exhaust pipe cross-sectional area of the inlet adapter is unchanged from the upstream end to the downstream end, and the exhaust adapter cross-sectional area of the outlet adapter is from the upstream end. The duct body is characterized in that the cross-sectional area of the exhaust path gradually increases from the portion where the inlet adapter is connected to the portion where the outlet adapter is connected.
(5) According to the invention of claim 5, in the exhaust pipe device of claim 3 or 4, the distance between the centers of the inlet adapter and the outlet adapter of the exhaust duct is excessively increased so that the straight pipe is horizontally disposed. The distance between the centers of the feeder outlet and the muffler inlet is the same as that of the center.
(6) The invention of claim 6 has a duct body having a single box structure in which a substantially folded passage portion is formed, and a first exhaust duct to which exhaust gas discharged from the supercharger outlet is guided; An exhaust pipe device having a straight pipe through which exhaust gas discharged from the first exhaust duct is guided and a second exhaust duct through which exhaust gas discharged from the straight pipe is guided is an excess of the first exhaust duct. The center-to-center distance between the feeder inlet and the muffler-side outlet is equal to the center-to-center distance between the supercharger outlet and the muffler inlet, the joint surface between the straight pipe and the first exhaust duct, and the straight pipe and the first exhaust duct. The joint surface with the two exhaust ducts is characterized by being orthogonal to the horizontal axis of the straight pipe.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1-5, one Embodiment of the exhaust pipe apparatus of this invention is described. FIG. 1 shows a state in which an exhaust pipe device according to an embodiment is attached between a supercharger outlet and a muffler inlet of an engine with a supercharger mounted on a construction machine. The engine ENG includes an engine main body 1, a supercharger 2, a muffler 6, and an exhaust pipe device 7 that guides exhaust gas discharged from the supercharger 2 to the muffler 6. The exhaust gas discharged from the engine 1 pressurizes the intake air to the engine 1 by the supercharger 2, is discharged, passes through the exhaust pipe device 7, and flows to the muffler 6. The exhaust gas is silenced by the muffler 6 and released into the atmosphere.
[0007]
The exhaust pipe device 7 includes an exhaust duct 3, a straight pipe 4, and an elbow duct 5. As shown in FIGS. 2A to 2C, the exhaust duct 3 is connected to a duct body 31 obtained by bending a flat plate cut into a predetermined shape into a box shape by bending and welding, and to the outlet of the supercharger 2. It is formed by welding a tubular inlet adapter 32 to be connected and a tubular outlet adapter 33 to be connected to the straight pipe 4. As shown in FIG. 3, the straight pipe 4 is a pipe that connects the exhaust duct 3 and the elbow duct 5, an inlet portion 42 to which the outlet adapter 33 of the exhaust duct 3 is connected, and an inlet adapter 52 of the elbow duct 5 described later. And an outlet portion 43 into which is inserted. As shown in FIG. 4, the elbow duct 5 is a tubular inlet adapter that is inserted into the outlet portion 43 of the straight pipe 4 into an elbow duct body 51 obtained by bending a flat plate cut into a predetermined shape into a box shape by bending and welding. 52 and a flange portion 53 provided with a flange connected to the muffler 6 are welded. Hereinafter, each part which comprises the exhaust pipe apparatus of one Embodiment is explained in full detail.
[0008]
――― Exhaust duct 3 ―――
From the relationship between the direction and position of the outlet of the supercharger 2 and the direction and position of the inlet of the muffler 6, the inlet adapter 32 and the outlet adapter 33 of the exhaust duct 3 are as shown in FIGS. The upper and lower positions of the duct body 31 are arranged so as to be substantially folded paths in the same direction. In order to suppress the ventilation resistance of the exhaust gas, it is necessary to increase the cross-sectional area of the passage path from the supercharger 2 to reduce the exhaust gas flow velocity. Therefore, the diameter of the inlet adapter 32 is adjusted to the outlet diameter of the supercharger 2, but the flow passage cross-sectional area of the duct body 31 is gradually increased so that the exhaust gas smoothly flows to the outlet adapter 33 having a larger diameter than the inlet adapter 32. To flow into. The width of the duct body 31 is substantially equal to the outer diameter of the inlet adapter 32 at the lower part of the duct body 31, that is, upstream of the flow path, and is substantially equal to the outer diameter of the outlet adapter 33 at the upper part of the duct body 31, that is, lower part of the flow path. . When this is viewed from the back, as shown in FIG. 2C, the width of the duct body 31 gradually increases in a tapered shape from the lower part to the upper part. Further, although the exhaust gas flowing direction is changed in the exhaust duct 3, in order to suppress the exhaust gas ventilation resistance, when the exhaust duct 3 is viewed from the side, as shown by the arrow in FIG. The exhaust gas flow path formed by the duct body 31 is bent by approximately 45 degrees so that the gas flowing direction gradually changes.
[0009]
The duct main body 31 having such a shape is formed by joining three types of four plates, that is, a front plate 311, a back plate 312, and a side plate 313, by welding. The front plate 311 and the back plate 312 are each formed by bending a flat plate cut into a predetermined shape at a plurality of positions at an angle of approximately 45 degrees so that the exhaust gas flows smoothly as described above. The front plate 311 is provided with a hole in a portion to which the inlet adapter 32 and the outlet adapter 33 that are exhaust gas inlets and outlets are attached. The side plate 313 is a flat plate cut into two target shapes. A bracket 34 for fixing the exhaust duct 3 to the engine body 1 is attached to one of the two side plates 313 as shown in FIG.
[0010]
The inlet adapter 32 is a short pipe 321 having an outer diameter substantially equal to the inner diameter of the exhaust gas outlet of the supercharger 2, and the outer periphery of the supercharger 2 side tip portion 322 is fitted to the outlet of the supercharger 2. Has been machined. Further, as shown in FIG. 2B, a lip 323 is welded to the outer periphery of the inlet adapter 32 so that it can be fastened to the exhaust gas outlet of the supercharger 2 with a V-shaped band (not shown) for fastening the pipe. ing.
[0011]
As described above, the outlet adapter 33 is a short pipe 331 having a diameter larger than that of the inlet adapter 32 in order to reduce the ventilation resistance of the exhaust gas. A ring 332 having a concave groove 333 provided on the outer periphery is welded to the downstream end of the outer periphery of the outlet adapter 33. As shown in FIG. 5, a piston ring 350 is fitted in the groove portion 333 of this ring and is inserted so as to be slidable in the axial direction with respect to the inlet portion 42 of the straight pipe 4 as described later. Absorbs direction vibration and prevents exhaust gas leakage. Further, since the outer periphery of the ring 332 is processed into a spherical shape, it is possible to prevent the outer periphery of the ring 332 and the inner peripheral surface 421 of the inlet portion 42 from being gnawed by vibration orthogonal to the axial direction.
[0012]
The exhaust duct 3 has the above-described substantially U-turn structure, thereby smoothly changing the flow direction of the exhaust gas discharged from the supercharger 2 and reducing the exhaust gas flow rate to reduce the ventilation resistance. Can do. Further, by making the distance between the centers of the inlet adapter 32 and the outlet adapter 33 equal to the distance between the centers of the outlet of the supercharger 2 and the inlet of the muffler 6, the straight pipe 4 described later is held horizontally. The straight pipe 4 and the elbow duct 5 can be easily designed.
[0013]
――― Straight pipe 4 ―――
The straight pipe 4 is a tubular member having an inner peripheral surface processed as shown in FIG. Instead of processing and using a circular tube, a flat plate may be bent into a tubular shape. The straight pipe 4 has a straight pipe main body 41, an inlet portion 42 and an outlet portion 43. The inner peripheral surfaces 421 and 431 of the inlet portion 42 and the outlet portion 43 are machined. As described above, the outlet adapter 33 of the exhaust duct 3 is inserted into the inlet 42 via the piston ring 350. Similarly, an inlet adapter 52 of an elbow duct 5 to be described later is slidably inserted in the axial direction with respect to the outlet portion 43 via the piston ring 550 to absorb axial vibration and prevent exhaust gas leakage. . Thus, the straight pipe 4 is held by the outlet adapter 33 of the exhaust duct 3 inserted into the inlet portion 42 and the inlet adapter 52 of the elbow duct 5 inserted into the outlet portion 43.
[0014]
As shown in FIGS. 3A and 3B, the axial direction of the straight pipe 4 with respect to the exhaust duct 3 and the elbow duct 5 is at the boundary portion between the inlet portion 42 and the outlet portion 43 on the inner peripheral surface of the straight pipe main body 41. A stopper 44 for restricting the movement of is projected.
[0015]
Since the straight pipe 4 has the above-described structure, it can induce exhaust gas as an exhaust pipe and absorb vibration between the supercharger 2 and the muffler 6.
[0016]
――― Elbow duct 5 ―――
The elbow duct 5 is a member for bending the flow of exhaust gas from the straight pipe 4 in the horizontal direction by 90 degrees and flowing it to the muffler 6. As shown in FIG. 4, the elbow duct 5 has a structure in which an elbow duct main body 51 is welded with an inlet adapter 52 and a flange portion 53. The elbow duct main body 51 has a box structure in which a cover plate 512 having a substantially U-shaped cross-section is bent at four locations approximately 45 degrees inside a bending direction of a base plate 511 bent at a right angle. In the base plate 511, a hole is formed in a portion where the inlet adapter 52 and the flange portion 53 serving as the inlet and outlet of the exhaust gas are welded. Due to the structure of the elbow duct main body 51, the exhaust gas flowing in from the inlet adapter 52 changes the flow direction by about 45 degrees in the elbow duct main body 51 as indicated by the arrow shown in FIG. And leaked.
[0017]
The inlet adapter 52 has the same shape as the outlet adapter 33 of the exhaust duct 3. That is, a ring 522 provided with a concave groove 523 on the outer periphery is welded to the downstream end of the outer periphery of the inlet adapter 52. A piston ring (not shown) is fitted in the groove portion 523 and is inserted so as to be slidable in the axial direction with respect to the outlet portion 43 of the straight pipe 4 to absorb axial vibration and prevent exhaust gas leakage. To do. In addition, since the outer periphery of the ring 522 is processed into a spherical shape, it is possible to prevent the outer periphery of the ring 522 and the inner peripheral surface 431 of the outlet portion 43 from being gnawed by vibration orthogonal to the axial direction.
[0018]
The flange portion 53 includes a short pipe portion 531 welded to the elbow duct main body 51 and a flange 532 for connecting the elbow duct 5 to the flange at the inlet of the muffler 6 with bolts and nuts.
[0019]
Since the elbow duct 5 has the above-described structure, the exhaust gas from the straight pipe 4 can be smoothly guided to the muffler 6.
[0020]
The exhaust gas discharged from the supercharger 2 is guided to the exhaust duct 3 by the exhaust pipe device of the above-described embodiment. The flow direction of the exhaust gas guided to the exhaust duct 3 can be gradually changed depending on the shape of the duct body 31. Moreover, since the cross-sectional area of the duct body 31 is gradually increased, the flow rate of the exhaust gas is gradually decreased, and the ventilation resistance is decreased. The exhaust gas discharged from the exhaust duct 3 passes through the straight pipe 4 and is sent to the muffler 6 after changing its flow direction by 90 degrees with the elbow duct. Further, vibration between the supercharger 2 and the muffler 6 is absorbed between the outlet adapter 33 of the exhaust duct 3 and the straight pipe 4 and between the inlet adapter 52 of the elbow duct 5 and the straight pipe 4.
[0021]
According to the exhaust pipe device having the above configuration, the following operational effects can be achieved.
(1) The exhaust duct 3 has a structure in which an inlet adapter 32 and an outlet adapter 33 having an exhaust path cross-sectional area larger than the exhaust path cross-sectional area of the inlet adapter 32 are provided in a duct body 31 having a single box structure. . As a result, the exhaust duct 3 can be produced with a simple structure, high productivity, and low cost.
(2) The structure of the exhaust pipe is such that exhaust gas from the supercharger 2 is guided to the muffler by the exhaust duct 3, the straight pipe 4, and the elbow duct 5. Furthermore, the exhaust path cross-sectional area of the outlet adapter 33 is made larger than the inlet adapter 32 of the exhaust duct 3, and the width of the duct body 31 is extended from the lower part where the inlet adapter 32 is connected to the upper part where the outlet adapter 33 is connected. The taper was gradually increased. As a result, the exhaust pipe device has a low exhaust gas ventilation resistance.
(3) The distance between the centers of the inlet adapter 32 and the outlet adapter 33 of the exhaust duct 3 is made equal to the distance between the centers of the outlet of the supercharger 2 and the inlet of the muffler 6. The joint surface between the inlet adapter 32 and the straight pipe and the joint surface between the outlet adapter 33 and the straight pipe 4 can be made perpendicular to the axis of the straight pipe 4. Thereby, the design and manufacture of the straight pipe 4 and the elbow duct 5 are facilitated and can be produced at low cost.
[0022]
In the exhaust pipe device 7 of the above-described embodiment, the orientation of the inlet adapter 32 and the outlet adapter 33 of the exhaust duct 3 is the same, but the present invention is not limited to this. Depending on the positional relationship between the outlet of the exhaust gas supercharger 2 and the inlet of the muffler 6, the orientation of the outlet adapter 33 relative to the inlet adapter 32 is the horizontal plane on which the outlet adapter 33 is disposed, whichever direction it faces. Good.
[0023]
In the exhaust pipe device 7 according to the embodiment described above, the outlet adapter 33 of the exhaust duct 3 is inserted into the straight pipe 4, but is not limited thereto. The straight pipe 4 may be inserted into the outlet adapter 33 of the exhaust duct 3. The same applies to the straight adapter 4 and the inlet adapter 52 of the elbow duct 5.
[0024]
In the exhaust pipe device 7 according to the embodiment described above, the duct body 31 of the exhaust duct 3 is tapered, but the present invention is not limited thereto. As shown in FIG. 6, a tapered box 37a may be provided in a duct body 31a whose passage cross-sectional shape is not tapered, and an inlet adapter 32a may be provided in the box 37a. Furthermore, the present invention is not limited to the above-described embodiment as long as the characteristic functions of the present invention are not impaired.
[0025]
In the above embodiment and its modifications, the inlet adapter disposed in the duct body is the inlet adapter 32, the outlet adapter disposed in the duct body is the outlet adapter 33, and the first exhaust duct is the exhaust duct 3. The second exhaust duct corresponds to the elbow duct 5 respectively.
[0026]
【The invention's effect】
As described above, according to the present invention, conventionally, an exhaust duct having a substantially folded passage structure in which a plurality of ring-shaped members obtained by obliquely cutting a conical pipe or a straight pipe is welded is provided with an inlet adapter and an outlet adapter. In addition, since it is formed as a single box structure, the exhaust duct and the exhaust pipe device can be produced with a simple structure, high productivity, and low cost.
[Brief description of the drawings]
FIG. 1 is a view showing a state in which an exhaust pipe device according to an embodiment of the present invention is attached between a supercharger outlet and a muffler inlet of an engine with a supercharger mounted on a construction machine.
2 is a diagram showing an exhaust duct 3 of the exhaust pipe device shown in FIG. 1. FIG. 3 is a diagram showing a straight pipe 4 of the exhaust pipe device shown in FIG. 1. FIG. 4 is a diagram showing an exhaust pipe device shown in FIG. FIG. 5 is a cross-sectional view showing a state in which the exhaust duct 3 and the straight pipe 4 are fitted in the exhaust pipe device shown in FIG. 1. FIG. 6 is a modified example of the exhaust pipe device of the present invention. Figure showing symbols [Explanation of symbols]
1 Engine Body 2 Supercharger 3 Exhaust Duct 31 Duct Body 32 Inlet Adapter 33 Outlet Adapter 4 Straight Pipe 5 Elbow Duct 6 Muffler

Claims (6)

A duct body having a single box structure in which a substantially folded passage portion is formed to connect the supercharger outlet to the muffler inlet;
An inlet adapter disposed in the duct body for guiding the exhaust gas discharged from the supercharger outlet to the duct body;
An outlet adapter disposed in the duct body for guiding the exhaust gas discharged from the duct body to a downstream device and having an exhaust path cross-sectional area larger than an exhaust path cross-sectional area of the inlet adapter. And exhaust duct. The exhaust duct according to claim 1,
The cross-sectional area of the exhaust path of the inlet adapter is unchanged from the upstream end to the downstream end,
The outlet adapter cross-sectional area of the outlet adapter is unchanged from the upstream end to the downstream end,
The exhaust duct is characterized in that an exhaust path cross-sectional area of the duct body gradually increases from a portion where the inlet adapter is connected to a portion where the outlet adapter is connected. An exhaust duct through which exhaust gas discharged from the supercharger outlet is guided;
A straight pipe through which exhaust gas discharged from the exhaust duct is guided;
In the exhaust pipe device comprising the straight pipe and a connection duct for connecting the muffler,
The exhaust duct is
A duct body having a single box structure in which a substantially folded passage portion is formed to connect the supercharger outlet to the muffler inlet;
An inlet adapter disposed in the duct body for guiding the exhaust gas discharged from the supercharger outlet to the duct body;
An outlet adapter disposed in the duct body for guiding the exhaust gas discharged from the duct body to a downstream device and having an exhaust path cross-sectional area larger than an exhaust path cross-sectional area of the inlet adapter. Exhaust pipe device. The exhaust pipe device according to claim 3,
The cross-sectional area of the exhaust path of the inlet adapter is unchanged from the upstream end to the downstream end,
The outlet adapter cross-sectional area of the outlet adapter is unchanged from the upstream end to the downstream end,
The exhaust pipe device, wherein the duct main body has an exhaust path sectional area gradually increasing from a portion where the inlet adapter is connected to a portion where the outlet adapter is connected. The exhaust pipe device according to claim 3 or 4,
The center-to-center distance between the inlet adapter and the outlet adapter of the exhaust duct is made equal to the center-to-center distance between the supercharger outlet and the muffler inlet so that the straight pipe is horizontally disposed. An exhaust pipe device characterized by that. A first exhaust duct having a duct body that is a single box structure in which a substantially folded passage portion is formed, to which exhaust gas discharged from a supercharger outlet is guided;
A straight pipe through which exhaust gas discharged from the first exhaust duct is guided;
An exhaust pipe device having a second exhaust duct through which exhaust gas discharged from the straight pipe is guided;
The center-to-center distance dimension between the supercharger-side inlet and the muffler-side outlet of the first exhaust duct is equal to the center-to-center distance dimension between the supercharger outlet and the muffler inlet.
The joint surface between the straight pipe and the first exhaust duct and the joint surface between the straight pipe and the second exhaust duct are orthogonal to the horizontal axis of the straight pipe. Exhaust pipe device.

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