rotary engine

Abstract

To improve fuel combustion performance of a rotary engine.SOLUTION: A recess 7 of an outer peripheral surface 2a of a rotor 2 is equipped with an L side recessed portion 7a that extends forward in a rotor rotating direction from a center in a longitudinal direction of an outer peripheral surface 2a, and a T side recessed portion 7b that continues to the L side recessed portion 7a and extends from the center to a front side in the rotor rotating direction. A cross section of the recess 7 when traversing the recess 7 by a plane orthogonal to the longitudinal direction of the outer peripheral surface 2a of the rotor 2 and passing through a center of the rotor 2, becomes the largest at a center part 7c in the longitudinal direction of the outer peripheral surface 2a, and the length of the L side recessed portion 7a is longer than the length of the T side recessed portion 7b.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to rotary engines. [Background technology]

[0002] In a rotary engine, a combustion chamber is formed between a rotor and a rotor housing having a trochoidal inner peripheral surface. A recess (concave) that forms the combustion chamber is formed on the outer peripheral surface of the rotor. Regarding this rotor recess, Patent Document 1 describes that the volume of the leading-side recess, which extends from the longitudinal center of the outer peripheral surface to the front in the rotor rotation direction, is made larger than the volume of the trailing-side recess, which extends to the front in the rotor rotation direction. The purpose of increasing the volume of the leading-side recess is to promote flame growth, enable advance ignition and shorten the ignition delay period, and improve thermal efficiency by advancing the center of gravity of combustion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-12410 Summary of the Invention [Problem to be solved by the invention]

[0004] However, promoting flame growth results in rapid combustion of the air-fuel mixture and rapid heat generation, which can lead to concerns about combustion noise and gas leakage, as well as increased cooling loss, which is detrimental to improving fuel efficiency. [Means for solving the problem]

[0005] In order to solve the above problem, the present invention is designed to suppress the flow velocity of the unburned mixture flowing from the trailing side toward the flame on the leading side near the top dead center of the compression stroke.

[0006] The rotary engine disclosed herein comprises: a rotor housing having a substantially elliptical trochoidal inner peripheral surface; side housings arranged on either side of the rotor housing and forming a rotor accommodating chamber together with the rotor housing; a substantially triangular rotor accommodated in the rotor accommodating chamber, dividing the rotor accommodating chamber into three working chambers, and rotating to move each working chamber circumferentially and cause each working chamber to perform intake, compression, expansion and exhaust strokes in sequence; an ignition plug provided in the rotor housing; and a control unit for controlling the operation of the ignition plug, wherein recesses are formed in each outer peripheral surface of the rotor that divides the working chambers, The recess in the outer peripheral surface of the rotor includes a leading-side recess (hereinafter referred to as an "L-side recess") extending from a center in the longitudinal direction of the outer peripheral surface to a front side in the direction of rotation of the rotor, and a trailing-side recess (hereinafter referred to as a "T-side recess") continuing from the L-side recess and extending from the center to a front side in the direction of rotation of the rotor, a cross-sectional area of ​​the recess when crossed on a plane perpendicular to the longitudinal direction of the outer peripheral surface of the rotor and passing through the center of the rotor is largest at a central portion in the longitudinal direction of the outer peripheral surface, and the length of the L-side recess is longer than the length of the T-side recess, The control unit is characterized by controlling the operation of the spark plug so that the ignition timing is advanced from the top dead center of the compression stroke (hereinafter referred to as "TDC"), where the spark plug faces the L-side recess.

[0007] According to this, the air-fuel mixture is ignited by a spark plug facing the L-side recess before TDC, and the flame propagates mainly to the L-side. The air-fuel mixture is supplied to the flame from the front side in the rotor rotation direction (hereinafter referred to as the "T-side"), causing the flame to grow. Because the rotor is rotating, the gap between the center of the rotor's outer periphery and the rotor housing becomes narrower as the rotor approaches TDC.

[0008] In contrast, in the above-mentioned rotary engine, the cross-sectional area of ​​the recess on the outer peripheral surface of the rotor is largest at the center of the outer peripheral surface. Therefore, around TDC, the supply speed of the mixture from the T-side to the flame growing forward in the rotor rotation direction (hereinafter referred to as the "L-side") of the rotor housing's minor axis position is prevented from increasing. In other words, the flow of the mixture from the T-side to the L-side is prevented from becoming strong. This prevents the combustion speed of the main combustion after ignition from increasing. In other words, it prevents combustion from becoming slow and sudden heat generation. This prevents cooling loss from increasing, which is advantageous for improving fuel efficiency, reducing combustion noise, and preventing gas leakage.

[0009] Furthermore, the fact that the cross-sectional area of ​​the recess on the rotor's outer peripheral surface is largest at the center of the rotor's outer peripheral surface in the longitudinal direction means that the volume of the recess on the L-side is relatively smaller than that of the center. In other words, the cross-sectional area of ​​the rotor's outer peripheral surface is increased at the center, but the volume of the recess on the L-side is reduced. This allows for slower combustion while maintaining the engine's compression ratio and ensuring thermal efficiency. This also leads to a smaller volume on the L-side than the spark plug, which is advantageous in suppressing the rapid growth of the flame after ignition.

[0010] Furthermore, the fact that the length of the L-side recess from the longitudinal center of the rotor's outer periphery is longer than the length of the T-side recess means that the range of rotor rotation angles at which ignition can occur when the spark plug is facing the L-side recess is wide, making it easier to advance the ignition timing in conjunction with EGR (exhaust gas recirculation).

[0011] Furthermore, the present invention In the L-side recess, the cross-sectional area gradually decreases from the central portion to one-half to one-third of the cross-sectional area of ​​the central portion as it moves toward the front side in the rotor rotation direction (hereinafter referred to as the "L side"), and this size extends toward the L side for a length that is at least six-tenths of the total length of the L-side recess. Therefore, rapid growth of the flame after ignition can be suppressed.

[0012] Furthermore, the present inventionIn the T-side recess, the bottom surface is gently inclined so that the depth of the recess gradually becomes shallower from the central portion in the longitudinal direction of the outer peripheral surface to the T-side end, and the cross-sectional area gradually and continuously decreases from the central portion to the T-side end.

[0013] Therefore, after TDC, the flow of the air-fuel mixture from the T-side of the rotor housing's minor axis to the L-side where the flame is present proceeds smoothly through the inclined T-side recess. This allows for a smooth supply of unburned air-fuel mixture, which in turn helps to suppress the occurrence or scale of so-called two-stage combustion, which is advantageous in reducing exhaust loss and, ultimately, cooling loss.

[0014] In one embodiment, the length of the T-side recess is 2 / 10 or more and 5 / 10 or less of the length of the L-side recess, which makes it possible to greatly advance the ignition timing while suppressing two-stage combustion and combustion noise.

[0015] In one embodiment, the length of the L-side recess is between 7 / 10 and 9 / 10 of the length from the longitudinal center of the outer circumferential surface to the L-side end of the outer circumferential surface, which widens the range of rotor rotation angles at which ignition can be achieved with the spark plug facing the L-side recess, which is advantageous for advancing the ignition timing.

[0016] In one embodiment, the spark plug is provided so as to ignite the air-fuel mixture in the working chamber on the L side of the minor axis position of the rotor housing, The control unit controls the spark plug so that it ignites at a timing advanced within a range of 55° or less from TDC facing the L-side recess. [Effects of the Invention]

[0017] According to the present invention, the heat generation of the main combustion after ignition can be prevented from becoming too sudden, so that cooling loss is not large, which is advantageous for improving fuel efficiency, reducing combustion noise and preventing gas leakage, and is also advantageous for advancing the ignition timing. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing an overview of a rotary piston engine according to an embodiment of the present invention; [Figure 2] FIG. 2 is a front view showing the rotor and rotor housing of the engine. [Figure 3] FIG. [Figure 4] Cross-sectional view taken along line IV-IV in Figure 3. [Figure 5] Cross-sectional view showing the size of the gap between the rotor and rotor housing at TDC. [Figure 6] FIG. 4 is a graph showing how the recess cross-sectional area changes in the longitudinal direction of the outer circumferential surface of the rotor. [Figure 7] A cross-sectional view showing the relationship between the rotor and rotor housing before and after TDC. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the scope of the present invention, its applications, or uses.

[0020] <Overall structure of the rotary engine> The rotary engine 1 (hereinafter simply referred to as engine 1) shown in Fig. 1 is mounted on a vehicle and has two rotors 2. An intermediate housing 4 is provided between two rotor housings 3, each housing accommodating a rotor 2. Side housings 5 ​​are provided on both outer sides of the two rotor housings 3. Focusing on one rotor housing 3, the intermediate housing 4 is located on one side of the rotor housing 3 and can be considered as a side housing that forms a rotor accommodating chamber 31 together with the rotor housing 3 and the side housing 5.

[0021] In Figure 1, the front side (right side of Figure 1) of the engine 1 is partially cut away to show the inside of the engine, and the rear side (left side of Figure 1) of the side housing 5 is also shown separated to show the inside of the engine. The symbol X in the figure indicates the rotation axis of the eccentric shaft serving as the output shaft.

[0022] As shown in Fig. 2, the rotor housing 3 has a trochoidal inner peripheral surface 3a that is substantially elliptical (bale-shaped) when viewed from the direction of the rotation axis X, which is described by a parallel trochoid curve. As shown in Fig. 1, the inner peripheral surface of the rotor housing 3, the inner surfaces 4a on both sides of the intermediate housing 4, and the inner surface 5a of the side housing 5 form a rotor accommodating chamber 31, and the rotor 2 is accommodated in this rotor accommodating chamber 31. The rotor accommodating chambers 31 on both sides of the intermediate housing 4 have the same configuration except that the rotation phase of the rotor 2 is different.

[0023] The rotor 2 has a generally triangular shape when viewed from the direction of the rotation axis X, with the center of each side bulging outward, and a recess 7 is formed on the generally rectangular outer peripheral surface 2a between the apexes of the triangle. Apex seals provided at each apex of the triangle of the rotor 2 come into sliding contact with the trochoid inner peripheral surface 3a of the rotor housing 3 as the rotor 2 rotates. The rotor 2 divides the interior of the rotor accommodating chamber 31 into three working chambers 8, as shown in FIG. 2 .

[0024] The rotor 2 is supported by an eccentric ring 6a of the eccentric shaft 6, and while rotating, it revolves around the rotation axis X in the same direction as the rotation (this rotation and revolution are, in a broad sense, simply referred to as the rotation of the rotor 2). During one rotation of the rotor 2, the three working chambers 8 move circumferentially, and each chamber undergoes an intake, compression, expansion (combustion), and exhaust stroke. The rotational force generated by this movement is output from the eccentric shaft 6 via the rotor 2.

[0025] In FIG. 2, the rotor 2 rotates clockwise as indicated by the arrow, and the rotor accommodating chamber 31 is divided by the major axis Y of the rotor accommodating chamber 31, which passes through the rotation axis X. The left side of the rotor accommodating chamber 31 is generally the area for the intake stroke and exhaust stroke, and the right side is generally the area for the compression stroke and expansion stroke.

[0026] 1, intake ports 11-13 and an exhaust port 10 open at locations corresponding to the intake stroke and exhaust stroke regions on the inner surface 4a of the intermediate housing 4 and the inner surface 5a of the side housing 5. Although not shown, a fuel injection valve that injects fuel into the working chamber 8 during the intake stroke or compression stroke is provided at the top of the rotor housing 3.

[0027] 2, the spark plug 9 is attached to the side of the rotor housing 3 at a position on the L side in the rotation direction of the rotor 2 (hereinafter referred to as the "rotor rotation direction") relative to the position of the minor axis Z of the rotor accommodating chamber 31 that passes through the rotation axis X, with its electrode exposed toward the rotor accommodating chamber 31. The major axis Y and the minor axis Z are perpendicular to each other.

[0028] Although not shown, the rotary engine 1 is provided with an EGR device that recirculates part of the exhaust gas to the intake passage, and the recirculation of the exhaust gas is performed according to the engine operating state.

[0029] The rotary piston engine 1 also includes a control unit as a control section that controls the operation of the engine, including the operation of the intake throttle valve, fuel injection valve, spark plugs 91 and 92, and EGR device.

[0030] <About the control unit> The control unit is based on a microcomputer and includes a central processing unit (CPU) that executes programs, a memory configured with, for example, RAM or ROM that stores programs and data, and a signal input / output (I / O) bus. Various information signals are input to the control unit from the vehicle's accelerator position sensor, vehicle speed sensor, engine rotation angle sensor, air-fuel ratio sensor, engine water temperature sensor, air flow sensor, etc.

[0031] The control unit determines the operating state of the engine 1 based on the input signal, and controls the throttle valve opening, the EGR rate by the EGR device, the ignition timing by the spark plug 9 in each working chamber 8, and the fuel injection amount and timing by the fuel injection valve according to the operating state. The ignition timing by the spark plug 9 is set to a range of 55° before BTDC (top dead center of the compression stroke) or less, and controls the timing of energization of the ignition coil based on this setting.

[0032] The ignition timing is controlled according to the EGR rate so that the center of combustion is located at an appropriate position for high thermal efficiency, between 10° and 30° ATDC (after top dead center of the compression stroke). As shown by the dotted line in Figure 2, when one of the apexes of the rotor 2 is positioned on the minor axis Z on the opposite side of the spark plug 9, the working chamber located on the opposite side of that apex is at TDC.

[0033] As the EGR rate increases, the ignition delay period becomes longer and the center of combustion gravity is retarded. Therefore, the ignition delay period is set according to the EGR rate, and the target heat generation start timing (target time for the apparent start of heat generation) is also set according to the EGR rate. Then, the ignition timing of the spark plug 9 is set to a time advanced by the ignition delay period from the target heat generation start timing.

[0034] <About the rotor recess> As shown in Figure 3, the recess 7 formed in the outer peripheral surface 2a of the rotor 2 (hereinafter referred to as the "rotor outer peripheral surface") extends long in the rotor rotation direction. The recess 7 includes an L-side recess 7a (hereinafter referred to as the "L-side recess 7a") extending from the center C of the rotor outer peripheral surface 2a in the longitudinal direction toward the L side, and a T-side recess 7b continuing from the L-side recess 7a and extending from the center of the rotor outer peripheral surface 2a toward the T side. The volume of this recess 7 is set so that the geometric compression ratio of the working chamber 8 is 9.7 or more.

[0035] The length L1 of the L-side recess 7a is longer than the length L2 of the T-side recess 7b. It is preferable that the length L2 of the T-side recess 7b is 2 / 10 or more and 5 / 10 or less of the length L1 of the L-side recess 7a (the length of the L-side recess 7a is 2 times or more and 5 times or less the length of the T-side recess 7b).

[0036] Furthermore, the length of the L-side recess 7a (the starting position of the L-side recess 7a on the L side) is preferably in the range of 7 / 10 to 9 / 10 of the length measured from the center of the longitudinal direction of the rotor outer peripheral surface 2a to the L-side end of the rotor outer peripheral surface 2a. On the other hand, the length of the T-side recess 7b (the starting position of the T-side recess 7b on the T side) is preferably in the range of 18 / 100 to 36 / 100 of the length measured from the center of the longitudinal direction of the rotor outer peripheral surface 2a to the L-side end of the rotor outer peripheral surface 2a.

[0037] The opening width (size in the rotor width direction) of the recess 7 is approximately constant from the front end of the L-side recess 7a in the rotor rotation direction to the central portion 7c of the rotor outer peripheral surface 2a. In the central portion 7c, the opening width widens slightly on both sides in the rotor width direction. The opening width gradually narrows from this central portion 7c toward the T-side end of the T-side recess 7b, and at this front end, the opening width is approximately the same size as the front end of the L-side recess 7a. Here, the "central portion 7c" refers to a portion that widens by approximately 4 to 8 degrees in terms of the central angle of the rotor 2.

[0038] As shown in Fig. 4, the recess 7 is deepest in a central portion 7c in the longitudinal direction of the rotor outer peripheral surface 2a. The L-side recess 7a has a bottom surface that slopes from the central portion 7c toward the L side, and its depth decreases to between one-third and one-half of the depth of the central portion 7c, and extends to the L side to a depth between one-third and one-half of that depth, and has a sloped portion at its front end in the rotor rotation direction, where the depth becomes zero. The T-side recess 7b has a bottom surface that slopes gently from the central portion 7c in the longitudinal direction of the outer peripheral surface 2a to the T-side end, so that the depth of the recess gradually decreases.

[0039] As shown in Figure 5 ((a), (b), and (c) are cross sections aa, bb, and cc in Figure 4 at the TDC position), the bottom surface of the recess 7 extends flat in the rotor width direction, with both side portions rising in an arc shape. Therefore, the cross-sectional area of ​​the recess 7 (the cross-sectional area when the recess 7 is cut across a plane perpendicular to the longitudinal direction of the rotor outer peripheral surface 2a and passing through the center of the rotor 2; hereinafter, referred to as the "recess cross-sectional area") is a size that roughly corresponds to the depth of the recess 7.

[0040] Figure 6 shows how the recess cross-sectional area changes in the longitudinal direction of the rotor outer peripheral surface 2a. The horizontal axis of Figure 6 is the position coordinate (unit: mm) with the origin (0) at the center of the rotor outer peripheral surface 2a in the longitudinal direction, with the L side indicated as positive and the T side indicated as negative.

[0041] The recess cross-sectional area is largest in a central portion 7c of the rotor outer peripheral surface 2a (in this embodiment, within a range of 5 mm from the origin 0 to the L side). From this central portion 7c toward the L side, the recess cross-sectional area gradually decreases to between one-third and one-half of the recess cross-sectional area at the central portion 7c up to a length of approximately one-tenth of the total length of the L-side recess 7a. From there, the recess cross-sectional area remains approximately constant, between one-third and one-half of the recess cross-sectional area at the central portion 7c, up to a length of approximately seven-tenths of the total length of the L-side recess 7a toward the L side, and then becomes zero at a distance of approximately one-tenth of the total length of the L-side recess 7a.

[0042] On the T-side, the bottom surface of the T-side recess 7b is gently inclined so that the depth of the T-side recess 7b gradually becomes shallower, and accordingly, the cross-sectional area of ​​the recess gradually decreases continuously from the central portion 7c to the T-side end of the T-side recess 7b. In Figure 6, reference numeral 9a denotes a plug hole of the spark plug 9.

[0043] <Action and effect> According to the above embodiment, the T-side recess 7b is shortened. That is, the T-side starting position of the T-side recess 7b is located on the L side of the position 36 / 100 of the length measured from the center of the longitudinal direction of the rotor outer peripheral surface 2a to the L-side end of the rotor outer peripheral surface 2a. This prevents two-stage combustion from becoming stronger, which is advantageous for improving fuel efficiency. Furthermore, since the T-side starting position of the T-side recess 7b is located on the T side of the position 18 / 100 of the length measured from the center of the longitudinal direction of the rotor outer peripheral surface 2a to the L-side end of the rotor outer peripheral surface 2a, the combustion noise is suppressed from becoming louder.

[0044] Furthermore, the L-side recess 7a is elongated. That is, the starting position of the L-side recess 7a on the L side is set to a range of 7 / 10 to 9 / 10 of the length measured from the longitudinal center of the rotor outer peripheral surface 2a to the L-side end of the rotor outer peripheral surface 2a. Therefore, even when the ignition timing is significantly advanced to account for ignition delay during EGR, the air-fuel mixture can be supplied to the plug hole of the spark plug 9 through the L-side recess 7a. This eliminates concerns about misfire.

[0045] When the air-fuel mixture is ignited by the spark plug 9 facing the L-side recess 7a at a time advanced from TDC, as shown by the dashed-dotted line in Figure 7, the flame propagates mainly to the L side. The air-fuel mixture is supplied from the T side to the flame, causing it to grow. As the rotor 2 rotates and approaches TDC, the gap between the central portion 7c of the rotor outer circumferential surface 2a and the rotor housing 3 becomes narrower.

[0046] In contrast, in the above embodiment, the cross-sectional area of ​​the recess 7 is largest at the central portion 7c of the rotor outer peripheral surface 2a. Therefore, as shown by the solid line in FIG. 7, the gap between the rotor 2 and the rotor housing 3 at the minor axis position is not excessively small, even at TDC. This prevents the supply velocity of the mixture from the T-side to the flame growing on the L-side of the rotor housing 3 relative to the minor axis position from increasing, i.e., prevents the flow of the mixture from the T-side to the L-side from becoming strong. This prevents the combustion velocity of the main combustion after ignition from increasing, which means that the combustion becomes slow and the heat generation becomes sudden. This prevents cooling loss from increasing, which is advantageous for improving fuel efficiency, reducing combustion noise, and preventing gas leakage.

[0047] Furthermore, since the cross-sectional area of ​​the recess 7a on the L side of the longitudinal central portion 7c of the rotor outer peripheral surface 2a is between 1 / 3 and 1 / 2 of the cross-sectional area of ​​the central portion 7c, the engine compression ratio can be maintained while slowing combustion, ensuring thermal efficiency, which is also advantageous in suppressing the rapid growth of the flame after ignition.

[0048] Furthermore, the bottom surface of the T-side recess 7b is gently inclined from the central portion 7c of the rotor outer peripheral surface 2a in the longitudinal direction to the T-side end, so that the depth of the recess 7b gradually decreases, and the cross-sectional area gradually decreases continuously from the central portion 7c to the T-side end. Therefore, after TDC, as indicated by the two-dot chain line in Figure 7, the flow of the air-fuel mixture from the T-side to the L-side where the flame exists, from the minor axis position of the rotor housing 3, proceeds smoothly through the inclined T-side recess 7b. Therefore, smoothly supplying the unburned air-fuel mixture also leads to suppression of the occurrence or magnitude of so-called two-stage combustion, which is advantageous for reducing exhaust loss and, ultimately, cooling loss. [Explanation of symbols]

[0049] 1. Rotary engine 2 rotors 2a Rotor outer surface 3 Rotor housing 3a Trochoid inner surface 4,5 Side housing 7 Recess 7a L side recess 7b T side recess 7c central part 8 Working chamber 9 Spark plugs 31 Rotor Containment Room Z short axis

Claims

1. a rotor housing having a substantially elliptical trochoidal inner peripheral surface; side housings disposed on either side of the rotor housing and forming a rotor accommodating chamber together with the rotor housing; a substantially triangular rotor accommodated in the rotor accommodating chamber, dividing three working chambers within the rotor accommodating chamber, and rotating to move each working chamber circumferentially, causing each working chamber to perform intake, compression, expansion and exhaust strokes in sequence; an ignition plug provided in the rotor housing; and a control unit for controlling the operation of the ignition plug, wherein recesses are formed in each outer peripheral surface of the rotor which divides the working chambers, the recess in the outer peripheral surface of the rotor includes a leading-side recess extending from a center in the longitudinal direction of the outer peripheral surface toward the front in the direction of rotation of the rotor, and a trailing-side recess continuing from the leading-side recess and extending from the center toward the front in the direction of rotation of the rotor, a cross-sectional area of ​​the recess when crossed on a plane perpendicular to the longitudinal direction of the outer peripheral surface of the rotor and passing through the center of the rotor is largest at a central portion in the longitudinal direction of the outer peripheral surface, and the length of the leading-side recess is longer than the length of the trailing-side recess, the control unit controls the operation of the spark plug so that the ignition timing is advanced from the top dead center of the compression stroke when the spark plug faces the L-side recess, the cross-sectional area of ​​the leading-side recess gradually decreases from one-third to one-half of the cross-sectional area of ​​the central portion as it moves forward in the rotor rotation direction, and extends forward in the rotor rotation direction with this size for a length that is at least six-tenths of the total length of the leading-side recess; a bottom surface of the trailing-side recess gently slopes from the longitudinal center of the outer peripheral surface to the front end in the direction of rotor rotation so that the depth of the recess gradually decreases, and the cross-sectional area gradually and continuously decreases from the central portion to the front end in the direction of rotor rotation.

2. In claim 1, A rotary engine characterized in that the length of the trailing side recess is between 2 / 10 and 5 / 10 of the length of the leading side recess.

3. In claim 1 or 2, A rotary engine characterized in that the length of the leading side recess is between 7 / 10 and 9 / 10 of the length from the longitudinal center of the outer peripheral surface to the front end of the outer peripheral surface in the rotor rotation direction.

4. In any one of claims 1 to 3, the spark plug is provided to ignite the air-fuel mixture in the working chamber forward of the minor axis position of the rotor housing in the rotor rotation direction, The rotary engine is characterized in that the control unit controls the spark plug so that it ignites at a timing advanced within a range of 55° or less from top dead center of the compression stroke facing the leading side recess.

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