Ignition timing structure of two-stroke multi-cylinder aero-engine

Abstract

According to the ignition timing structure of the two-stroke multi-cylinder aero-engine, the aero-engine is provided with a magnetor, the magnetor is composed of a magnetic steel rotor and a pair of magnetic electrodes, the magnetic steel rotor is installed on a crankshaft, and the pair of magnetic electrodes are symmetrically installed on the two sides of the magnetic steel rotor; the magnetic steel rotor is in a disc shape, a pair of permanent magnets is symmetrically embedded in the outer circle face of the magnetic steel rotor, and N poles and S poles of the permanent magnets are arranged in the clockwise direction. The magnetic electrode is composed of a silicon steel sheet and a coil, the silicon steel sheet is in an n shape and is provided with a short left supporting leg and a long right supporting leg, and the coil is fixed to the left supporting leg and points to the circle center of the magnetic steel rotor. When the ignition advance angle is adjusted, the left edge of the right supporting leg is aligned with the right edge of the N pole of the permanent magnet, and the right edge of the left supporting leg is close to the left edge of the N pole of the permanent magnet. According to the ignition timing structure, timing marks do not need to be carved on parts, the influence of part machining errors on ignition timing is eliminated, and the accuracy and stability of ignition timing are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of aviation engines, in particular to an ignition timing structure of a two-stroke multi-cylinder aviation engine. Background Art

[0002] A two-stroke aircraft engine has multiple cylinders arranged in opposite directions. When working, the piston in each cylinder requires a magnetic motor to provide ignition timing.

[0003] Refer to the attached Figure 1 . The existing magnetic motor 1 is mainly composed of a magnetic steel rotor 11 and a stator disk 9. The stator disk 9 is installed on the crankcase, and the magnetic steel rotor is installed on the crankshaft. Permanent magnets are installed in the magnetic motor rotor 11, and a protruding trigger block 115 is provided on the edge of the magnetic steel rotor 11. Two types of coils are installed on the stator disk 9, one is a generating coil 91 located in the inner cavity of the magnetic motor rotor, which is used to cut the magnetic lines of force to generate electricity; the other is an induction coil 92 located on the outside of the magnetic steel rotor. When the magnetic steel rotor 11 rotates with the crankshaft, the trigger block 115 approaches the induction coil 92, and an ignition signal is generated in the induction coil 92.

[0004] During operation, the spark plug ignites the fuel-air mixture in the cylinder before the piston reaches top dead center. To facilitate determining the ignition advance angle and ignition time, timing marks are provided on the edge of the magnetic steel rotor and timing lines are provided on the crankcase. When the piston is at top dead center, the timing marks are aligned with the timing lines. However, this ignition timing method is only applicable to single-cylinder engines and is not suitable for multi-cylinder two-stroke aircraft engines. Moreover, the accuracy of ignition timing is largely limited by the machining precision of components such as the magneto, crankshaft connecting rod, and piston. If a component is out of tolerance, even if the timing mark is aligned with the timing lines, the ignition timing will be inaccurate. It is well known that ignition timing has a significant impact on the combustion and work performance of the fuel-air mixture in the cylinder. Ignition too early or too late will affect the engine's output power. Utility Model Content

[0005] In order to overcome the deficiencies in the background art, the present invention discloses an ignition timing structure for a two-stroke multi-cylinder aircraft engine, the purpose of which is to:

[0006] 1. Suitable for adjusting the ignition timing of multi-cylinder aircraft engines;

[0007] 2. Eliminate the influence of component processing errors on ignition timing and improve the accuracy of ignition timing.

[0008] In order to achieve the above-mentioned purpose of the utility model, the utility model adopts the following technical solutions:

[0009] An ignition timing structure for a two-stroke multi-cylinder aircraft engine comprises a magneto comprising a magnetic steel rotor and a pair of magnetic electrodes, the magnetic steel rotor being mounted on a crankshaft, and the pair of magnetic electrodes being symmetrically mounted on either side of the magnetic steel rotor; the magnetic steel rotor being disc-shaped, with a pair of permanent magnets symmetrically embedded on the outer circumference of the magnetic steel rotor, with the north and south poles of the permanent magnets arranged in a clockwise direction; the magnetic electrodes comprising silicon steel sheets and coils, the silicon steel sheets being η-shaped, with a shorter left leg and a longer right leg, the coil being fixed to the left leg and pointing toward the center of the magnetic steel rotor; and when adjusting the ignition advance angle, the left edge of the right leg is aligned with the right edge of the permanent magnet's north pole, and the right edge of the left leg is close to the left edge of the permanent magnet's north pole.

[0010] To further improve the technical solution, a hub is installed on the crankshaft, a connecting disk is provided on the hub, and a plurality of rivet holes are evenly distributed along the circumference of the connecting disk; an arc-shaped connecting hole corresponding to the connecting hole is provided on the magnetic steel rotor, and the magnetic steel rotor is mounted on the connecting disk with an adjustable angle by rivets.

[0011] To further improve the technical solution, an external spline is provided on the output shaft of the crankshaft, an internal spline is provided in the propeller hub, and the propeller hub is mounted on the output shaft of the crankshaft through the spline structure.

[0012] To further improve the technical solution, a fixing plate is installed on the crankcase of the aircraft engine, and a plurality of threaded holes are provided on the fixing plate; a plurality of long holes are provided on the silicon steel sheet, and a pair of magnetic electrodes are adjustably mounted on the fixing plate by bolts.

[0013] After implementing the above technical solution, compared with the background technology, the beneficial effects produced by the present invention are:

[0014] 1. This ignition timing structure is applicable to two-cylinder, four-cylinder, eight-cylinder and other two-stroke aircraft engines. It only needs to adjust the timing of one cylinder to achieve the timing adjustment of all cylinders.

[0015] 2. This timing structure does not require the engraving of timing marks on parts, eliminating the influence of machining errors of parts such as magneto, crankshaft, connecting rod, piston, etc. on ignition timing, thus improving the accuracy and stability of ignition timing;

[0016] 3. The coil can generate electricity and provide ignition signals for the spark plug on any cylinder, without the need for pairing;

[0017] 4. This ignition timing structure reduces the magnetic gap, improves the power generation efficiency of the coil and the strength of the ignition signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attachment Figure 1 Shown is a structural schematic diagram of an existing magnetic motor.

[0019] Attachment Figure 2 Shown is a perspective view of a horizontally opposed two-stroke aircraft engine.

[0020] Attachment Figure 3 Shown is a front view of a horizontally opposed two-stroke aircraft engine.

[0021] Attachment Figure 4 Shown is a schematic diagram of the position of the piston before the crankshaft rotates.

[0022] Attachment Figure 5 Shown is a schematic diagram of the structure of a magnetic motor.

[0023] Attachment Figure 6 Shown is a schematic diagram of the installation structure of the magnetic motor on the fixed plate and the hub.

[0024] Attachment Figure 7 Shown is the attached Figure 2 Enlarged view of point P in the middle.

[0025] Attachment Figure 8 Shown is a schematic diagram of the magnetic steel rotor and magnetic electrode timing.

[0026] Attachment Figure 9 The diagram shows the position of the piston after the crankshaft rotates 180°.

[0027] In the accompanying drawings: 1. magnetic motor; 11. magnetic steel rotor; 111. disk body; 112. permanent magnet; 113. arc-shaped connecting hole; 114. weight-reducing structure; 115. trigger block; 12. magnetic electrode; 121. silicon steel sheet; 1211. left support leg; 1212. right support leg; 122. coil; 2. dial indicator; 3. hub; 31. connecting disk; 32. rivet hole; 33. internal spline; 4. bolt; 5. fixing plate; 6. crankshaft; 61. connecting rod; 62. piston; 7. cylinder; 8. crankcase; 9. stator disk; 91. generating coil; 92. induction coil. DETAILED DESCRIPTION

[0028] The following describes preferred embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely intended to illustrate the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that, in the description of the present invention, terms such as "front," "rear," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or component must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can mean fixed, detachable, or integral; mechanical or electrical; direct, indirect through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0029] Refer to the attached Figure 2 and attached Figure 3 . Figure 2 and attached Figure 3 It can be seen that a horizontally opposed two-stroke aircraft engine has four cylinders 7, which are horizontally opposed. The cylinder diameter is 66 mm and the piston stroke is 40 mm.

[0030] Refer to the attached Figure 4 . Accordingly, the crankshaft 6 located in the crankcase 8 has four connecting rods 61, and a piston 62 is installed at the small end of the connecting rod 61. When the two pistons 62 on the left are at the top dead center, the two pistons 62 on the right are at the bottom dead center. In order to detect whether the piston 62 has reached the ignition advance angle, an external thread is provided on the sleeve rod of the dial indicator 2. The dial indicator 2 is screwed into the spark plug hole of the 1# cylinder 7, and the probe of the dial indicator 2 is against the top of the piston 62. The crankshaft 6 also has two output shafts, one of which is provided with an external spline.

[0031] Refer to the attached Figure 2 , Attachment Figure 3 , Attachment Figure 5 The magnetic motor 1 is composed of a magnetic steel rotor 11 and a pair of magnetic poles 12 . The magnetic steel rotor 11 is mounted on the crankshaft 6 , and the pair of magnetic poles 12 are symmetrically mounted on both sides of the magnetic steel rotor 11 .

[0032] The magnetic steel rotor 11 comprises a disc-shaped body 111 made of aluminum alloy. A pair of permanent magnets 112 are symmetrically embedded on the outer surface of the body 111, centered about the axis of the body 111. The north and south poles of the permanent magnets 112 are arranged in a clockwise direction. Eight arc-shaped connection holes 113 are evenly distributed along the circumference of the magnetic steel rotor 11, centered about the axis of the body 111. Furthermore, weight-reducing structures 114 are symmetrically positioned on the magnetic steel rotor 111.

[0033] The magnetic electrode 12 consists of a silicon steel sheet 121 and a coil 122. The silicon steel sheet 121 is η-shaped, with a shorter left leg 1211 and a longer right leg 1212. The left leg 1211 is parallel to the right leg 1212. The coil 122 is fixed on the left leg 1211 and points to the center of the magnetic steel rotor 11.

[0034] Refer to the attached Figure 6 A fixing plate 5 is mounted on the crankcase 8. The fixing plate 5 has four threaded holes for mounting a pair of magnetic electrodes 12. Two elongated holes are provided in the silicon steel sheet 121 along the radial direction of the magnetic steel rotor 11. The pair of magnetic electrodes 12 are mounted on the fixing plate 5 via bolts 4. The elongated holes allow adjustment of the mounting distance of the magnetic electrodes 12 relative to the magnetic steel rotor 11.

[0035] The hub 3 is mounted on the crankshaft 6. An internal spline 33 is provided inside the hub 3. The hub 3 is mounted on the output shaft of the crankshaft 6 via the spline structure. A connecting disk 31 is provided on the hub 3. Eight rivet holes 32 are evenly distributed along the circumference of the connecting disk 31. The eight rivet holes 32 are arc-shaped holes with the axis of the hub 3 as the center. The magnetic steel rotor 11 is coaxially mounted on the connecting disk 31. Rivets are inserted into the arc-shaped connecting hole 113 of the magnetic steel rotor 11 and the arc-shaped hole of the connecting disk 31 to fix the magnetic steel rotor 11 on the hub 3. In this way, the installation angle of the magnetic steel rotor 11 on the hub 3 can be adjusted. Since the hub 3 is mounted on the crankshaft 6 via the spline structure, this installation angle is also the installation angle of the magnetic steel rotor 11 on the crankshaft 6.

[0036] Before adjusting the ignition timing, first determine the ignition advance angle of the crankshaft. Figure 4 Place dial gauge 2 in the spark plug hole of cylinder #1 (7) of the aircraft engine. Turn crankshaft 6 clockwise until piston 62 is at top dead center, and adjust the dial gauge 2's needle to zero. Then, turn crankshaft 6 counterclockwise until the needle of dial gauge 2 reaches a certain value. Note that this value is calculated by reverse engineering the aircraft engine's ignition advance angle. In this example, the needle of the dial gauge reaches 3.3 mm counterclockwise.

[0037] Refer to the attached Figure 7Then adjust the installation angle of the magnetic steel rotor 11 on the crankshaft 6 so that the left edge of the right leg 1212 is aligned with the right edge of the permanent magnet 112N pole, and the right edge of the left leg 1211 is close to the left edge of the permanent magnet 112N pole. Finally, use rivets to fix the magnetic steel rotor 11 to the hub 3 to complete the ignition timing of the piston 62 in the 1# cylinder 7.

[0038] Refer to the attached Figure 8 . When the piston 62 in the 1# cylinder 7 moves upward and is 3.3 mm away from the top dead center, the crankshaft 6 is in the position of the ignition advance angle. At this time, the magnetic steel rotor 11 is rotated to align the right edge of the permanent magnet's N pole with the left edge of the right leg 1212, and the left edge of the permanent magnet's N pole is close to the right edge of the left leg 1211. At this time, the magnetic field strength at the left leg 1211 suddenly increases, and a strong ignition signal is generated in the coil 122, and the spark plug on the 1# cylinder begins to ignite in advance. Since the piston movement in the 1# cylinder is symmetrical with the piston movement in the 2# cylinder, the coil can be connected to the spark plugs on the 1# cylinder and the 2# cylinder so that the spark plugs on the 1# cylinder and the 2# cylinder ignite at the same time.

[0039] Refer to the attached Figure 9 After the crankshaft 6 rotates 180° clockwise, the pistons 62 in the 3# and 4# cylinders move upward and are 3.3 mm away from the top dead center. At this time, the permanent magnet 112 on the magnetic steel rotor 11 turns to the other magnetic electrode 12 on the opposite side. The coil 122 of this magnetic electrode 12 is connected to the spark plugs on the 3# and 4# cylinders. When the left edge of the right leg 1212 is aligned with the right edge of the permanent magnet 112's North pole, and the left edge of the permanent magnet 112's North pole approaches the right edge of the left leg 1211, the spark plugs on the 3# and 4# cylinders ignite simultaneously.

[0040] In reality, the spark plugs on all four cylinders fire simultaneously for every 180° of crankshaft rotation, except for the two cylinders where the pistons are at bottom dead center. The advantage of this design is that the ignition signal generated by the coil, after being boosted by the high-voltage coil, can cause the spark plugs on any cylinder to fire, eliminating the need for pairing.

[0041] Refer again to the attached Figure 1. The existing magnetic steel rotor 11 is clamped with a magnet, and a protruding trigger block 115 is provided on the edge of the magnetic steel rotor 11. The ignition principle is: when the trigger block 115 is not close to the induction coil 92, the magnetic steel rotor 11 has a relatively weak magnetic field strength, and at this time the induction coil 92 induces a lower electrical signal. When the trigger block 115 approaches the induction coil 92, the gap between the induction coil 92 and the magnetic steel rotor 11 suddenly becomes smaller, and the magnetic field strength suddenly becomes larger, and the induction coil 92 can induce a higher electrical signal, thereby forming an ignition signal. Since the difference between the higher electrical signal and the lower electrical signal is small, the ignition signal is not obvious, and the engine may not ignite.

[0042] Compared with the attached Figure 1 In the magnetic motor, the magnetic steel rotor 11 of the present invention is not provided with a trigger block. The long strip hole and the bolt 4 can bring the magnetic electrode 12 closer to the magnetic steel rotor 11, reducing the magnetic gap and improving the power generation efficiency of the coil 122 and the strength of the ignition signal. More importantly, the coil of the present invention can both generate electricity and generate an ignition signal. Since the disk 111 does not have magnetic conductivity, when the permanent magnet 112 is not close to the coil 122, the coil 122 basically will not induce an electrical signal. When the permanent magnet 112 is close to the coil 122, the coil 122 can induce a very high electrical signal. Since the signal difference is obvious, a clear ignition signal can be formed to ensure smooth ignition of the engine.

[0043] This timing structure is applicable to two-, four-, and eight-cylinder two-stroke aircraft engines. Adjusting the timing of all cylinders requires adjusting the timing of only one cylinder. More importantly, this timing structure eliminates the need for engraving timing marks on components, eliminating the impact of machining errors on ignition timing from components such as the magneto 1, crankshaft 6, connecting rod 61, and piston 62, thereby improving the accuracy and stability of ignition timing.

[0044] Parts not described in detail are prior art. Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ignition timing structure for a two-stroke multi-cylinder aircraft engine having a magneto, characterized in that: The magnetic motor consists of a magnetic steel rotor and a pair of magnetic electrodes. The magnetic steel rotor is mounted on the crankshaft, and the pair of magnetic electrodes are symmetrically mounted on both sides of the magnetic steel rotor. The magnetic steel rotor is disc-shaped, and a pair of permanent magnets are symmetrically embedded on the outer surface of the magnetic steel rotor, with the N pole and S pole of the permanent magnet arranged in a clockwise direction. The magnetic electrodes are composed of silicon steel sheets and coils. The silicon steel sheets are η-shaped, with a shorter left leg and a longer right leg. The coil is fixed on the left leg and points to the center of the magnetic steel rotor. When adjusting the ignition advance angle, the left edge of the right leg is aligned with the right edge of the permanent magnet's N pole, and the right edge of the left leg is close to the left edge of the permanent magnet's N pole.

2. The ignition timing structure of a two-stroke multi-cylinder aircraft engine according to claim 1, characterized in that: A hub is installed on the crankshaft, and a connecting disk is provided on the hub. A plurality of rivet holes are evenly distributed along the circumference of the connecting disk; an arc-shaped connecting hole corresponding to the connecting hole is provided on the magnetic steel rotor, and the magnetic steel rotor is installed on the connecting disk with an adjustable angle through rivets.

3. The ignition timing structure of a two-stroke multi-cylinder aircraft engine according to claim 2, characterized in that: An external spline is provided on the output shaft of the crankshaft, and an internal spline is provided in the propeller hub. The propeller hub is installed on the output shaft of the crankshaft through the spline structure.

4. The ignition timing structure of a two-stroke multi-cylinder aircraft engine according to claim 1, characterized in that: A fixing plate is installed on the crankcase of the aircraft engine, and a plurality of threaded holes are arranged on the fixing plate; a plurality of long strip holes are provided on the silicon steel sheet, and a pair of magnetic electrodes are adjustably mounted on the fixing plate through bolts.

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