rotary piston engine

Abstract

To provide an exhaust structure which enables an exhaust passage to be disposed around an engine body compactly and stably in a rotary piston engine.SOLUTION: An exhaust passage is provided with: a first exhaust passage fixed to a first outer side surface of an engine body and extending forward from an exhaust port; a second exhaust passage extending from a front end of the first exhaust passage to the other side in an engine width direction along a front surface of the engine body; and a third exhaust passage extending rearward from the other side end as seen in the engine width direction of the second exhaust passage along a second outer side surface which is an outer side surface at the other side of the engine body in the engine width direction. A support part for supporting the third exhaust passage is provided on the second outer side surface of the engine body, and a purifier is disposed rearward of a connection position between the third exhaust passage and the support part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a rotary piston engine. [Background technology]

[0002] In vehicle engines, a purification device for purifying exhaust gas is installed in the exhaust passage, and a long exhaust passage is used to guide the exhaust gas outside the vehicle, etc., and the exhaust passage is heavy, so it is necessary to stably support the exhaust passage around the engine body.

[0003] Patent Document 1 discloses a structure in which an exhaust passage is arranged to extend in a predetermined direction from one side of the engine body along this side, with the aim of providing stable support for the exhaust passage, and the exhaust passage downstream of the purification device (catalytic converter in Patent Document 1) is fixed to a transmission connected to the engine body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-155440 Summary of the Invention [Problem to be solved by the invention]

[0005] In vehicle engines and the like, in addition to stably supporting the exhaust passage as described above, it is also required to arrange the exhaust passage compactly around the engine body. In particular, in hybrid vehicles, in addition to the engine, a motor and a generator must be mounted on the vehicle as a drive source, so there is a strong demand for a compact arrangement of the exhaust passage. In contrast, in the structure of Patent Document 1, the exhaust passage is arranged to extend in one direction from the engine body, and the area occupied by the exhaust passage in this extension direction becomes larger. As such, the structure of Patent Document 1 leaves room for improvement in terms of arranging the exhaust passage compactly around the engine body.

[0006] The present invention has been made in consideration of the above circumstances, and has as its object to provide an exhaust structure in a rotary piston engine that allows an exhaust passage to be arranged compactly and stably around the engine body. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a rotary piston engine including an engine body having a rotor that rotates around an eccentric shaft extending in a front-rear direction and a rotor housing chamber that houses the rotor, and an exhaust passage through which exhaust gas discharged from the engine body flows, wherein the engine body is provided with an exhaust port that opens on a first outer surface that is an outer surface on one side in a width direction of the engine that is perpendicular to the front-rear direction and that directs exhaust gas into the exhaust passage, and the exhaust passage includes a first exhaust passage that is fixed to the first outer surface and extends forward from the exhaust port, and a second exhaust passage that extends from a front end of the first exhaust passage a second exhaust passage extending from the end of the second exhaust passage on the other side in the engine width direction along the front surface of the engine body to the other side in the engine width direction; a third exhaust passage extending rearward from the end of the second exhaust passage on the other side in the engine width direction along a second outer surface that is the outer surface of the engine body on the other side; and a purification device connected to the rear end of the third exhaust passage and purifying the exhaust gas, wherein a support part is fixed to the second outer surface of the engine body to connect the second outer surface and the third exhaust passage and support the third exhaust passage, and the purification device is arranged rearward of the connection position of the third exhaust passage with the support part.

[0008] In this configuration, the portions of the exhaust passages that extend from the exhaust ports (the first exhaust passage, the second exhaust passage, and the third exhaust passage) extend along the first outer side surface, the front surface, and the second outer side surface of the engine body, and the exhaust passages are arranged along the outer side surface of the engine body so as to surround it, which allows the exhaust passages to be arranged compactly around the engine body.

[0009] Moreover, in this configuration, the exhaust passage is supported on the first and second outer surfaces of the engine body, which face each other. Therefore, the exhaust passage can be stably supported on the engine body. Also, the purification device is disposed rearward of the connection position between the support part that supports the exhaust passage (third exhaust passage) on the second outer surface and the third exhaust passage, and the exhaust passage upstream of the purification device and the purification device are disposed separately in front of and behind a line connecting the connection position between the support part and the third exhaust passage and the fixed position of the exhaust passage (first exhaust passage) and the first outer surface. Therefore, the weight balance of the exhaust passage on the engine body in the fore-and-aft direction is made nearly equal, and the exhaust passage including the purification device can be stably supported on the engine body.

[0010] In the above configuration, preferably, the engine body includes a front fixing portion that fixes the first exhaust passage to the first outer surface, and a rear fixing portion that fixes the first exhaust passage to a position rearward of the front fixing portion on the first outer surface, and the connection position between the third exhaust passage and the support portion in the fore-and-aft direction is set midway between the front fixing portion and the rear fixing portion (Claim 2).

[0011] This configuration makes it possible to more evenly balance the weight of the exhaust passage on the engine body in the front-rear direction.

[0012] In the above configuration, preferably, the purification device is formed so as to extend while curving from the rear end of the third exhaust passage to the other side in the engine width direction, and further includes a fixed member fixed to the rear surface of the engine body, and a second support part and a third support part connecting the fixed member to the purification device and supporting the purification device, respectively, wherein the connecting position between the second support part and the purification device is rearward of the connecting position between the third exhaust passage and the support part, and the connecting position between the third support part and the purification device is rearward of the connecting position between the second support part and the purification device and on the other side in the engine width direction (claim 3).

[0013] According to this configuration, the purification device is supported at three different positions, so that the purification device can be stably supported.

[0014] In the above configuration, the second exhaust passage is preferably supported only by the first exhaust passage and the third exhaust passage (claim 4).

[0015] According to this configuration, the second exhaust passage located between the first exhaust passage and the third exhaust passage is not fixed to the engine body, so that thermal expansion and contraction of the first, second and third exhaust passages can be tolerated, and the thermal stress applied to these passages can be reduced.

[0016] In the above configuration, the first exhaust passage, the second exhaust passage, and the third exhaust passage are preferably stainless steel sheet metal parts (claim 5).

[0017] According to this configuration, the weight of the exhaust passage can be reduced compared to when the exhaust passage is made of cast parts.

[0018] In the above configuration, the engine body may be a one-rotor rotary piston engine having only one rotor, and may include a rotor housing surrounding the rotor and a pair of side housings provided on both sides of the rotor housing in the front-to-rear direction, and one exhaust port provided in each of the pair of side housings (Claim 6). [Effects of the Invention]

[0019] As described above, according to the rotary piston engine of the present invention, the exhaust passage can be arranged compactly and stably around the engine body. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a system diagram showing a schematic configuration of an engine according to an embodiment of the present invention. [Figure 2] FIG. 1 is a schematic plan view of a powertrain system including an engine. [Figure 3] FIG. 1 is a schematic front view of a powertrain system. [Figure 4] FIG. 1 is a schematic side view of an engine. [Figure 5] FIG. 2 is a schematic side view of the rear of the engine. [Figure 6] 6 is a schematic diagram showing a part of a cross section taken along line VI-VI in FIG. 5. [Figure 7] FIG. 3 is a schematic perspective view showing a part of the powertrain system as seen in the direction of arrow Y1 in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0021] (Overall engine configuration) Fig. 1 is a system diagram showing the schematic configuration of a rotary piston engine 1 according to an embodiment of the present invention. Hereinafter, the rotary piston engine 1 will be simply referred to as the engine 1. Fig. 2 is a schematic plan view of a powertrain system 200 that includes the engine 1 and is mounted on a vehicle, Fig. 3 is a schematic front view of the powertrain system 200, and Fig. 4 is a schematic side view of the engine 1. Note that Fig. 2 does not show an intake passage 3, which will be described later.

[0022] The engine 1 according to this embodiment is mounted on a vehicle. For example, the engine 1 is mounted on a hybrid vehicle equipped with a motor as a drive source for wheels. In this embodiment, the engine 1 is incorporated into a powertrain system 200 mounted on the vehicle and including the motor and the like. Specifically, as shown in FIG. 2 , the powertrain system 200 has the engine 1, a generator 202, a reduction gear 203, and a motor 201. The generator 202 is driven by the engine 1 to generate electricity and charge a battery (not shown). The motor 201 rotates by power supplied from the battery. The reduction gear 203 reduces the rotation of the motor 201 and transmits it to the wheels. In this embodiment, the engine 1 is used as a device that drives the generator 202 as described above.

[0023] The engine 1 comprises an engine body 10, an intake passage 3 through which intake air introduced into the engine body 10 flows, an exhaust passage 5 through which exhaust gas discharged from the engine body 10 flows, and an EGR device 4 that recirculates a portion of the exhaust gas flowing through the exhaust passage 5 back into the intake passage 3.

[0024] (Engine body) The engine body 10 is a single-rotor type. The engine body 10 has an eccentric shaft 12 extending in a predetermined direction, a rotor 11 rotating around the eccentric shaft 12, and a rotor accommodating chamber R that accommodates the rotor 11. The engine body 10 has a rotor housing 13 that surrounds the outer periphery of the rotor 11, and a pair of side housings 14, 14 provided on both sides of the rotor housing 13 in the predetermined direction (i.e., on both sides in the direction along the rotation axis of the rotor 11). The rotor accommodating chamber R is defined by the rotor housing 13 and the two side housings 14, 14. The rotor housing 13 has an inner circumferential surface that follows a two-node peritrochoid curve. The rotor 11 rotates along the inner circumferential surface of the rotor housing 13 by planetary rotation relative to the eccentric shaft 12.

[0025] The engine body 10 has a rear cover 20 that is connected to one side housing 14 on the opposite side (in the above-mentioned predetermined direction) from the rotor housing 13 and that houses a flywheel. The engine body 10 has a front cover 22 that is connected to the other side housing 14 on the opposite side (in the above-mentioned predetermined direction) from the rotor housing 13.

[0026] The engine 1 is mounted on the vehicle in a position where the predetermined direction coincides with the substantially horizontal direction, i.e., the rotation axis of the rotor 11 and the eccentric shaft 12 extend substantially horizontally. In the following description, the predetermined direction (the direction along the longitudinal direction of the eccentric shaft 12 and the rotation axis of the rotor 11) is referred to as the front-rear direction. This predetermined direction (front-rear direction) corresponds to the "front-rear direction" in the claims. In the following description, the side where the rear cover 20 is provided is referred to as the rear, and the side where the front cover 22 is provided is referred to as the front. In the following description, the up-down direction when the engine 1 is mounted on the vehicle is simply referred to as the up-down direction, and the left-right direction when the engine body 10 is viewed from behind is simply referred to as the left-right direction. This left-right direction corresponds to the "engine width direction" in the claims.

[0027] The powertrain system 200 is configured so that the engine 1, the generator 202, the reduction gear 203, and the motor 201 are arranged in this order from the front. Specifically, the generator 202 is connected to the rear surface of the engine 1, that is, the rear surface of the rear cover 20, the reduction gear 203 is connected to the rear surface of the generator 202, and the motor 201 is connected to the rear surface of the reduction gear 203.

[0028] In this embodiment, the engine 1 is mounted on the vehicle in an orientation in which the aforementioned front-to-rear direction of the engine 1 (the longitudinal direction of the eccentric shaft 12 and the direction along the rotation axis of the rotor 11) coincides with the vehicle width direction, and the aforementioned left-to-right direction coincides with the vehicle front-to-rear direction. Note that the view of the engine body 10 in FIG. 1 is a schematic cross-sectional view as viewed from the front. Also, FIG. 2 is a view of the powertrain system 200 as viewed from above, FIG. 3 is a view of the powertrain system 200 as viewed from the front, and FIG. 4 is a view of the portion of the powertrain system 200 surrounding the engine 1 as viewed from the right.

[0029] The engine body 10 is formed with an intake port 16 connected to the intake passage 3 to introduce intake air from the intake passage 3 into the rotor housing chamber R, and an exhaust port 15 connected to the exhaust passage 5 to guide exhaust air from the rotor housing chamber R to the exhaust passage 5. The intake port 16 opens to the upper right side of the rotor housing chamber R, and the exhaust port 15 opens to the lower right side of the rotor housing chamber R. In other words, the engine body 10 is configured so that the rotor 11 rotates clockwise when viewed from the front, and the upper right, upper left, lower left, and lower right regions of the rotor housing chamber R roughly correspond to the areas where the intake stroke, compression stroke, expansion stroke, and exhaust stroke are performed, respectively. In other words, the engine 1 is mounted on a vehicle so that the areas where each stroke is performed are located as described above in the vertical direction.

[0030] Two intake ports 16 and two exhaust ports 15 are provided in the engine body 10. The engine body 10 is a side-port rotary piston engine, and the intake ports 16 and the exhaust ports 15 are formed in the side housings 14. Specifically, one intake port 16 is formed in the upper part of each of the two side housings 14, and each intake port 16 opens at the upper part of the right side surface (the outer right surface) of each side housing 14. One exhaust port 15 is formed in the lower part of each of the two side housings 14, and each exhaust port 15 opens at the lower part of the right side surface of each side housing 14. The two exhaust ports 15 are shaped approximately symmetrically in the front-rear direction and open at approximately the same height on the right side surfaces of the two side housings 14. Similarly, the two intake ports 16 are shaped approximately symmetrically in the front-rear direction and open at approximately the same height on the right side surfaces of the two side housings 14.

[0031] The engine body 10 is fitted with a fuel injector 17 that injects fuel into the rotor housing R, and an ignition plug 18 that adds fuel to the mixture of fuel and air formed in the rotor housing R. The fuel injector 17 is fitted so as to face the upper end of the rotor housing R (more specifically, at a position offset from the upper end towards the spark plug 18), and the spark plug 18 is fitted so as to face the lower left part of the rotor housing R.

[0032] (intake passage) The intake passage 3 is provided with, in this order from the upstream side, an air cleaner 31 that removes foreign matter contained in the intake air, and a throttle valve 32 that opens and closes the intake passage 3 to adjust the amount of intake air introduced into the engine body 10 (rotor accommodating chamber R). The throttle valve 32 is housed in a throttle valve case 33 and is driven by an actuator 34 fixed to the throttle valve case 33. The portion of the intake passage 3 downstream of the throttle valve case 33 constitutes an intake manifold 38 that communicates with the two intake ports 16, 16 and distributes the intake air to these two intake ports 16, 16. The intake manifold 38 is fixed to the right side surface of the engine body 10 in an orientation extending upward from near the openings of the intake ports 16 on the right side surface of each side housing 14.

[0033] An air flow meter sensor SN1 that detects the flow rate of intake air passing through the intake passage 3 is provided downstream of the air cleaner 31. The intake manifold 38 is also provided with an intake air temperature sensor SN2 that detects the intake air temperature, which is the temperature of the gas passing through it.

[0034] (exhaust passage) The exhaust passage 5 includes an exhaust manifold 52 that communicates with the two exhaust ports 15 and where the exhaust gases guided from these exhaust ports 15 join together, and a downstream exhaust passage 53 that extends downstream (in the direction of exhaust gas flow) from the downstream end of the exhaust manifold 52. The exhaust passage 5 also includes a purification device 51 for purifying the exhaust. The detailed structure of the exhaust passage 5 and the support structure for the exhaust passage 5 will be described later.

[0035] (EGR device) The EGR device 4 includes an EGR passage 40 that connects the exhaust passage 5 and the intake passage 3. In the EGR passage 40, an EGR cooler 41 that cools EGR gas, which is exhaust gas flowing through the EGR passage 40, and an EGR valve 42 that opens and closes the EGR passage 40 to adjust the amount of EGR gas introduced into the intake manifold 38 are provided in this order from the upstream side (in the flow direction of the EGR gas). The EGR valve 42 is housed in an EGR valve case 43 and is driven by an EGR valve actuator 44 fixed to the EGR valve case 43.

[0036] The EGR device 4 is disposed to the right of the engine body 10. Specifically, as shown in FIG. 3, an EGR valve case 43 incorporating an EGR valve 42 and an EGR valve actuator 44 are disposed to the right of the engine body 10 and behind the intake manifold 38. The EGR cooler 41 is disposed to the right of the engine body 10, vertically between the intake manifold 38 and the exhaust manifold 52, and extends in the front-to-rear direction. The EGR cooler 41 is a water-cooled cooler that cools the EGR gas by heat exchange between the coolant and the EGR gas. A coolant inlet pipe 41b for introducing the coolant into the EGR cooler 41 and a coolant outlet pipe 41a for discharging the coolant from the EGR cooler 41 are attached to the EGR cooler 41.

[0037] (Details of the exhaust passage and exhaust passage support structure) The detailed structure of the exhaust passage 5 and the support structure of the exhaust passage 5 will be described below. Fig. 5 is a schematic side view of the rear part of the engine 1 as seen from the left. Fig. 6 is a schematic view showing a part of the cross section taken along line VI-VI in Fig. 5. Fig. 7 is a schematic perspective view showing a part of the powertrain system 200 as seen from the direction of arrow Y1 in Fig. 2.

[0038] In the following description of the exhaust manifold 52, upstream and downstream in the exhaust gas flow direction are simply referred to as upstream and downstream. Furthermore, the open ends of the exhaust ports 15, 15 formed on the right side surface of the side housing 14 are simply referred to as the open ends. Furthermore, the side housing 14 located at the front of the two side housings 14 is referred to as the front side housing 14A, and the exhaust port formed in the front side housing 14A (i.e., the front exhaust port of the two exhaust ports 15, 15) is referred to as the front exhaust port 15A. Furthermore, the side housing 14 located at the rear of the two side housings 14 is referred to as the rear side housing 14B, and the exhaust port formed in the rear side housing 14B (i.e., the rear exhaust port of the two exhaust ports 15, 15) is referred to as the rear exhaust port 15B.

[0039] As described above, the exhaust passage 5 includes the exhaust manifold 52 that communicates with the exhaust ports 15, 15, and the downstream exhaust passage 53 that constitutes the portion downstream of the exhaust manifold 52.

[0040] The exhaust manifold 52 extends forward from the rear exhaust port 15B along the right side surface 10A, which is the outer surface on the right side of the engine body 10. The exhaust manifold 52 communicates with the rear exhaust port 15B at its rear end and communicates with the front exhaust port 15A at its intermediate portion in the front-to-rear direction. The front end portion of the exhaust manifold 52 has a shape that bulges out diagonally forward and to the right. In other words, the front end portion of the exhaust manifold 52 curves leftward, and the front end portion of the exhaust manifold 52 wraps around to the front of the engine body 10.

[0041] The downstream exhaust passage 53 includes a first passage portion 53A extending leftward from the front end (downstream end) of the exhaust manifold 52 along the front surface 10B of the engine body 10, a second passage portion 53B extending rearward from the left end of the first passage portion 53A along the left side surface 10C, which is the outer surface on the left side of the engine body 10, a purification device 51 connected to the rear end (downstream end) of the second passage portion 53B so as to curve leftward, and a third passage portion 53C extending leftward from the left end of the purification device 51. The first passage portion 53A extends leftward from the front end portion of the exhaust manifold 52 and then extends diagonally upward to the left. The second passage portion 53B extends along the upper portion of the left side surface 10C of the engine body 10.

[0042] The purification device 51 is composed of a catalytic device 51A that purifies exhaust gas through catalytic action, a filter device 51B that is disposed downstream of the catalytic device 51A and captures particulate matter in the exhaust gas, and a connecting passage 51C that connects the catalytic device 51A and the filter device 51B. Specifically, the catalytic device 51A has a catalyst body that supports a catalyst and a case member that houses the catalyst body. Similarly, the filter device 51B has a main body that functions as a filter and a case member that houses the main body. The catalytic device 51A may be, for example, one that supports a three-way catalyst.

[0043] The exhaust passage 5 is a stainless steel sheet metal part. Specifically, the exhaust manifold 52, the first passage portion 53A, the second passage portion 53B, the third passage portion 53C, the connecting passage 51C of the purification device 51, the case member of the catalytic device 51A, and the case member of the filter device 51B are all made of stainless steel and manufactured from sheet metal.

[0044] Here, the right side in the left-right direction corresponds to "one side" and the left side corresponds to "the other side" in the claims. The right side surface 10A of the engine body 10 corresponds to "first outer surface" in the claims, and the left side surface 10C corresponds to "second outer surface" in the claims. The exhaust manifold 52 corresponds to "first exhaust passage" in the claims, the first passage portion 53A corresponds to "second exhaust passage" in the claims, and the second passage portion 53B corresponds to "third exhaust passage" in the claims.

[0045] (Exhaust manifold fixing structure) The exhaust manifold 52 is fixed to the right side surface 10A of the engine body 10.

[0046] Specifically, the exhaust manifold 52 has a plate-shaped mounting portion 52G that extends along the right side surface 10A of the engine body 10. Four stud bolts 101 to which the mounting portion 52G is fixed are attached to the right side surface 10A of the engine body 10. The mounting portion 52G has through holes formed at positions corresponding to the stud bolts 101. The stud bolts 101 are inserted into the through holes of the mounting portion 52G, and nuts 91 are screwed onto the stud bolts 101, thereby fixing the exhaust manifold 52 to the right side surface 10A of the engine body 10.

[0047] Of the four stud bolts 101, two stud bolts 101 are disposed above and below the rear exhaust port 15B, and protrude rightward from the right side surface of the rear side housing 14B. Hereinafter, the two stud bolts 101 disposed above and below the rear exhaust port 15B will be referred to as rear stud bolts 101B, 101B, respectively, where appropriate. The two rear stud bolts 101B, 101B are disposed at the same position relative to each other in the front-to-rear direction.

[0048] The remaining two stud bolts 101, 101 are disposed forward of the rear stud bolts 101B, 101B. The two stud bolts 101, 101 disposed forward of the rear stud bolt 101B are disposed above and below the front exhaust port 15A, respectively, and protrude rightward from the right side surface of the front side housing 14A. Hereinafter, the two stud bolts 101 disposed above and below the front exhaust port 15A will be referred to as front stud bolts 101A, 101A, respectively, where appropriate. The two front stud bolts 101A, 101A are disposed at the same position relative to each other in the front-to-rear direction.

[0049] The rear stud bolt 101B located above the rear exhaust port 15B and the front stud bolt 101A located above the front exhaust port 15A are disposed at the same position in the vertical direction. The rear stud bolt 101B located below the rear exhaust port 15B and the front stud bolt 101A located below the front exhaust port 15A are disposed at the same position in the vertical direction.

[0050] The two rear stud bolts 101B correspond to the "rear fixing portion" in the claims, and the two front stud bolts 101A correspond to the "front fixing portion" in the claims.

[0051] (Downstream exhaust passage fixing structure) The exhaust manifold 52 and the downstream exhaust passage 53 are connected via flanges. Specifically, a flange 52F is provided at the front end (downstream end) of the exhaust manifold 52. A flange 53F is provided at the upstream end of the downstream exhaust passage 53, i.e., at the right end of the first passage portion 53A. The exhaust manifold 52 and the downstream exhaust passage 53 are connected by connecting these flanges 52F, 53F with bolts and nuts.

[0052] Furthermore, the downstream exhaust passage 53 is connected (supported) to the left side surface 10C of the engine body 10 by the front bracket 400, and is connected (supported) to the generator housing case 230 by the intermediate bracket 500 and the rear bracket 600. The generator housing case 230 is a case that houses the main body parts of the generator 202 and the reducer 203, and is fixed to the rear surface of the engine body 10 with bolts. The front bracket 400 corresponds to the "support part" in the claims, the intermediate bracket 500 corresponds to the "second support part" in the claims, and the rear bracket 600 corresponds to the "third support part" in the claims. Furthermore, the generator housing case 230 corresponds to the "fixed member" in the claims.

[0053] Specifically, the front bracket 400 has four brackets (a first bracket 401, a second bracket 402, a third bracket 403, and a fourth bracket 404).

[0054] The first bracket 401 has a plate-shaped mounting portion 401A extending in the fore-and-aft direction along the left side surface 10C of the engine body 10, an extension portion 401B curving diagonally forward and left from the front edge of the mounting portion 401A, and a vertical wall portion 401C extending forward from the front edge (left edge) of the extension portion 401B.

[0055] The mounting portion 401A of the first bracket 401 is fixed to the left side surface 10C of the engine body 10. Specifically, a front bracket fixed portion 111 to which the mounting portion 401A of the first bracket 401 and therefore the front bracket 400 are fixed is provided on the left side surface 10C of the engine body 10. The front bracket fixed portion 111 is provided in the vertical center of the left side surface of the rear cover 20 of the engine body 10. The mounting portion 401A of the first bracket 401 is fixed to this front bracket fixed portion 111 with a bolt 92.

[0056] The second bracket 402 has a plate-shaped vertical wall portion 402A extending along the left side surface of the vertical wall portion 401C of the first bracket 401, and a horizontal wall portion 402B extending leftward from the upper edge of the vertical wall portion 402A. The vertical wall portion 402A of the second bracket 402 is fixed to the vertical wall portion 401C of the first bracket 401 with a bolt 93.

[0057] The third bracket 403 has a vertical wall portion 403A extending downward from the left side surface of the second passage portion 53B and a horizontal wall portion 403B extending leftward from the lower edge of the vertical wall portion 403A. The fourth bracket 404 has a vertical wall portion 404A extending downward from the right side surface of the second passage portion 53B and a horizontal wall portion 404B extending leftward from the lower edge of the vertical wall portion 404A and contacting the horizontal wall portion 403B of the third bracket 403. The horizontal wall portion 404B of the fourth bracket 404 passes below the second passage portion 53B and extends to a position to the left of the second passage portion 53B. The horizontal wall portion 403B of the third bracket 403, the horizontal wall portion 404B of the fourth bracket 404, and the horizontal wall portion 402B of the second bracket 402 are overlapped in the vertical direction and fixed by a common bolt 94.

[0058] The upper part of the vertical wall portion 403A of the third bracket 403 is fixed by welding to the left side surface of the rear end portion of the second passage portion 53B, and the vertical wall portion 404A of the fourth bracket 404 is fixed by welding to the right side surface of the rear end portion of the second passage portion 53B.

[0059] In this manner, in this embodiment, the front bracket 400 includes the third bracket 403 and the fourth bracket 404 fixed by welding to the rear end of the second passage section 53B, the second bracket 402 fixed to the third bracket 403 and the fourth bracket 404 by bolts 94, and the first bracket 401 fixed to the second bracket 402 by bolts 92, and is fixed to the front bracket fixed portion 111, so that the rear end of the second passage section 53B is supported on the engine body 10 by the front bracket 400.

[0060] As described above, the extending portion 401B of the first bracket 401 curves diagonally forward and leftward from the front edge of the mounting portion 401A fixed to the front bracket fixed portion 111. Accordingly, the vertical wall portion 401C of the first bracket 401, the second bracket 402 fixed thereto, and the horizontal wall portion 403B of the third bracket 403 and the horizontal wall portion 404B of the fourth bracket 404 fixed to the second bracket 402 are located forward of the mounting portion 401A. As a result, the coupling position P1 between the second passage portion 53B and the front bracket 400 is located forward of the rear cover 20. Furthermore, the coupling position P1 between the second passage portion 53B and the first bracket 401 (front bracket 400) is located midway in the front-rear direction between the position X1 of the front stud bolts 101A, 101A and the position X2 of the rear stud bolts 101B, 101B.

[0061] The intermediate bracket 500 has two brackets (a fifth bracket 501 and a sixth bracket 502).

[0062] The fifth bracket 501 has a plate shape that extends in the left-right direction along the upper surface of the generator housing case 230.

[0063] A right end of the fifth bracket 501 is fixed to the generator housing case 230. Specifically, an outer surface 230A of the generator housing case 230 is provided with an intermediate bracket fixed portion 232 to which the right end of the fifth bracket 501, and therefore the intermediate bracket 500, is fixed. More specifically, the generator housing case 230 includes a differential case 231 that protrudes leftward from the lower part of the engine body 10 when viewed from the front. The inside of the differential case 231 houses mainly the differential gear of the main body of the speed reducer 203. The intermediate bracket fixed portion 232 is provided on an upper surface 231A of the differential case 231. The differential case 231 has a shape that bulges out to the left, and the upper surface 231A of the differential case 231 curves diagonally downward and leftward from the left side surface 10C of the engine body 10 when viewed from the front. The right end of the fifth bracket 501 is fixed to the intermediate bracket fixed portion 232 by a bolt 95, and the fifth bracket 501 extends leftward from the intermediate bracket fixed portion 232.

[0064] The sixth bracket 502 has a plate-shaped horizontal wall portion 502A extending diagonally forward and left along the upper surface of the fifth bracket 501, and a pair of vertical wall portions 502B rising upward from both widthwise edges of the horizontal wall portion 502A. Each vertical wall portion 502B extends upward from each edge of the horizontal wall portion 502A and then extends diagonally forward and left.

[0065] The horizontal wall portion 502A of the sixth bracket 502 is fixed to the left end portion of the fifth bracket 501 by a bolt 96, and the front edges of each vertical wall portion 502B of the sixth bracket 502 are fixed to the right side surface of the connecting passage 51C by welding.

[0066] In this manner, in this embodiment, the intermediate bracket 500, which includes the sixth bracket 502 fixed by welding to the right side of the connecting passage 51C and the fifth bracket 501 fixed to the sixth bracket 502 by bolts 96, is fixed to the intermediate bracket fixed portion 232, so that the connecting passage 51C is connected (supported) to the generator housing case 230 by the intermediate bracket 500.

[0067] The rear bracket 600 has two brackets (a seventh bracket 601 and an eighth bracket 602).

[0068] The seventh bracket 601 has a horizontal wall portion 601A extending in the left-right direction, and a vertical wall portion 601B extending downward from the front and left edges of the horizontal wall portion 601A.

[0069] A right end portion of seventh bracket 601 is fixed to generator housing case 230. Specifically, a rear bracket fixed portion 233 to which seventh bracket 601 and therefore rear bracket 600 are fixed is provided on top surface 231A of differential case 231 of generator housing case 230, at a position diagonally rearward and left of intermediate bracket fixed portion 232. A right end portion of seventh bracket 601 is fixed to rear bracket fixed portion 233 with bolt 95, and seventh bracket 601 extends leftward from rear bracket fixed portion 233.

[0070] The eighth bracket 602 has a plate-shaped horizontal wall portion 602A extending along the upper surface of the seventh bracket 601, and a vertical wall portion 602B rising upward from the front edge of the horizontal wall portion 602A.

[0071] A horizontal wall portion 602A of the eighth bracket 602 is fixed to a horizontal wall portion 601A of the seventh bracket 601 by welding, and a vertical wall portion 502B of the eighth bracket 602 is fixed to the right side surface of the filter device 51B by welding.

[0072] In this manner, in this embodiment, the rear bracket 600, which includes the eighth bracket 602 fixed by welding to the right side surface of the filter device 51B and the seventh bracket 601 fixed by welding to the eighth bracket 602, is fixed to the rear bracket fixed portion 233, and the connecting passage 51C is supported on the generator housing case 230 by the rear bracket 600.

[0073] Here, the connection positions between each of the brackets 400, 500, 600 and the downstream exhaust passage 53 are set so that the center of gravity P10 of the downstream exhaust passage 53 is located within the area surrounded by these three connection positions.

[0074] Specifically, a connection position P2 between the intermediate bracket 500 and the connecting passage 51C (specifically, a fixed position between each vertical wall portion 502B of the sixth bracket 502 and the connecting passage 51C) is located rearward of a connection position P1 between the front bracket 400 and the second passage portion 53B, and a connection position between the rear bracket 600 and the filter device 51B (specifically, a fixed position between the vertical wall portion 602B of the eighth bracket 602 and the filter device 51B) is located rearward and leftward of the connection position P2 between the intermediate bracket 500 and the connecting passage 51C. A center of gravity P10 of the downstream exhaust passage 53 is located within a triangular area X that connects these connection positions P1, P2, and P3. In this embodiment, the center of gravity P10 of the downstream exhaust passage 53 is located in the catalytic device 51A.

[0075] As described above, the downstream-side exhaust passage 53 is fixed at its upstream end to the exhaust manifold 52, and is fixed at the rear end of its second passage portion 53B to the engine body 10 via the front bracket 400. On the other hand, the first passage portion 53A of the downstream-side exhaust passage 53 is not directly fixed to the engine body 10, and is supported only by the exhaust manifold 52 and the second passage portion 53B.

[0076] (effect, etc.) As described above, in the above embodiment, the exhaust manifold 52 extends along the right side surface 10A of the engine body 10, the first passage portion 53A extends along the front surface 10B of the engine body 10, and the second passage portion 53B extends along the left side surface 10C of the engine body. The portions of the exhaust manifold 52 extending from the exhaust ports 15 are compactly arranged around the engine body 10 so as to extend along the outer surfaces of the engine body 10 in three directions. This improves the layout flexibility around the engine body 10. In particular, in the above embodiment, the engine body 10 is mounted on a vehicle so that the right side surface on which the exhaust ports 15 are open and on which the exhaust manifold 52 is provided faces forward in the longitudinal direction of the vehicle. This reduces the area occupied by the exhaust passage 5 in the forward direction of the engine body 10, thereby increasing the flexibility in the positioning of the engine body 10 in the vehicle.

[0077] Moreover, in the above embodiment, the exhaust manifold 52 is supported on the right side surface 10A of the engine body 10 by the stud bolts 101, and the second passage portion 53B is supported on the left side surface 10C of the engine body 10 by the front bracket 400. In other words, the exhaust passage 5 is supported on the opposing outer side surfaces 10A and 10C of the engine body 10. Therefore, the exhaust passage 5 can be stably supported on the engine body 10.

[0078] Furthermore, the purification device 51 is disposed rearward of a connection position P1 between the exhaust passage 5 and a front bracket 400 that supports the second passage portion 53B on the left side surface 10C of the engine body 10. As a result, the purification device 51 and the exhaust passage 5 upstream of the purification device 51 are disposed separately at the front and rear of the line X3 that connects the connection position P1 between the second passage portion 53B and the front bracket 400 and the connection position between the exhaust manifold 52 and the engine body 10 (the center position between the front and rear stud bolts 101A and 101B). Specifically, this makes it possible to even out the weight balance of the exhaust passage on the engine body in the front-to-rear direction, and the exhaust passage 5 including the purification device 51 can be stably supported on the engine body 10.

[0079] In particular, in the above embodiment, the connection position P1 between the second passage portion 53B and the front bracket 400 is located midway in the front-to-rear direction between the position X1 of the front stud bolts 101A, 101A and the position X2 of the rear stud bolts 101B, 101B. This makes it possible to more evenly balance the weight of the exhaust passage 5 on the engine body 10 in the front-to-rear direction.

[0080] In the above embodiment, the purification device 51, which curves leftward from the rear end (downstream end) of the second passage portion 53B, is supported by the intermediate bracket 500 and the rear bracket 600 on the generator housing case 230, which is fixed to the rear surface of the engine body 10, so that the heavy purification device 51 can be stably supported. Moreover, a connection position P2 between the purification device 51 and the intermediate bracket 500 is set rearward of a connection position P1 between the front bracket 400, which supports the second passage portion 53B, which is the exhaust passage 5 upstream of the purification device 51, and the second passage portion 53B, and a connection position P3 between the purification device 51 and the rear bracket 600 is set rearward and leftward of the connection position P2 between the purification device 51 and the intermediate bracket 500. Therefore, the purification device 51 can be supported at three different positions, so that the purification device 51 can be reliably and stably supported.

[0081] Furthermore, the first passage portion 53A is not directly fixed to the engine body 10, but is supported only by the exhaust manifold 52 and the second passage portion 53B. This allows the exhaust manifold 52, the first passage portion 53A, and the second passage portion 53B to thermally expand and contract. In other words, the displacement of the first passage portion 53A allows the exhaust manifold 52 or the second passage portion 53B to thermally expand and contract. This reduces the thermal stress in each of these portions.

[0082] In addition, in the above embodiment, the exhaust manifold 52, the first passage portion 53A, and the second passage portion 53B are all made of stainless steel sheet metal, which can reduce the weight compared to when they are made of cast iron or the like.

[0083] (Variation) In the above embodiment, the member fixed to the rear surface of the engine body 10 and to which the intermediate bracket 500 and the rear bracket 600 are fixed is the generator housing case 230, but this member is not limited to the generator housing case 230.

[0084] In the above embodiment, the rotary piston engine is a one-rotor type having only one rotor 11, but the above configuration may also be applied to a rotary piston engine having a plurality of rotors 11. [Explanation of symbols]

[0085] 3 Intake passage 5 Exhaust passage 10 Engine body 10A Right side of engine body (first outer surface) 10B Front of engine body 10C Left side of engine body (second outer surface) 11 rotor 13 Rotor housing 14 Side housing 15 Exhaust port 51 Purification equipment 52 Exhaust manifold (first exhaust passage) 53A First passage section (second exhaust passage) 53B Second passage section (third exhaust passage) 101A Front stud bolt (front fixing part) 101B Rear stud bolt (rear fixing part) 230 Generator housing case (fixed member) 400 Front bracket (support part) 500 Intermediate bracket (second support part) 600 Rear bracket (third support part) R Rotor Containment Room

Claims

1. A rotary piston engine including an engine body having a rotor that rotates around an eccentric shaft extending in a front-rear direction and a rotor housing chamber that houses the rotor, and an exhaust passage through which exhaust gas discharged from the engine body flows, the engine body includes an exhaust port that opens to a first outer surface that is an outer surface on one side in an engine width direction perpendicular to the front-rear direction and that guides exhaust gas to the exhaust passage, the exhaust passage includes a first exhaust passage fixed to the first outer surface and extending forward from the exhaust port; a second exhaust passage extending from a front end of the first exhaust passage along a front surface of the engine body to the other side in the engine width direction; a third exhaust passage extending rearward from an end of the second exhaust passage on the other side in the engine width direction along a second outer surface that is the outer surface on the other side of the engine body; and a purification device connected to a rear end of the third exhaust passage and purifying exhaust gas, a support portion is fixed to the second outer surface of the engine body, the support portion connecting the second outer surface and the third exhaust passage and supporting the third exhaust passage, 11. A rotary piston engine according to claim 10, wherein the purification device is disposed rearward of a position where the third exhaust passage is connected to the support portion.

2. 2. The rotary piston engine according to claim 1, the engine body includes a front fixing portion that fixes the first exhaust passage to the first outer surface, and a rear fixing portion that fixes the first exhaust passage to a position rearward of the front fixing portion on the first outer surface, a connecting position between the third exhaust passage and the support portion in the front-rear direction being set midway between the front fixing portion and the rear fixing portion;

3. 2. The rotary piston engine according to claim 1, the purification device is formed to extend while curving from a rear end of the third exhaust passage toward the other side in the engine width direction, a fixed member fixed to a rear surface of the engine body, and a second support portion and a third support portion connecting the fixed member and the purification device to support the purification device, a connecting position between the second support portion and the purification device is rearward of a connecting position between the third exhaust passage and the support portion, a connecting position between the third support portion and the purification device being rearward of a connecting position between the second support portion and the purification device and on the other side in the engine width direction;

4. 2. The rotary piston engine according to claim 1, 10. A rotary piston engine, comprising: a first exhaust passage and a third exhaust passage; a second exhaust passage supported only by the first exhaust passage and the third exhaust passage;

5. 2. The rotary piston engine according to claim 1, 10. A rotary piston engine, comprising: a first exhaust passage, a second exhaust passage, and a third exhaust passage, each of which is made of stainless steel sheet metal.

6. The rotary piston engine according to any one of claims 1 to 5, the engine body is a one-rotor rotary piston engine having only one rotor, and includes a rotor housing surrounding the rotor, and a pair of side housings provided on both sides of the rotor housing in the front-rear direction, 10. A rotary piston engine, comprising: a pair of side housings each having one exhaust port;

Images