JPH077582Y2 - Engine ignition - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention utilizes an ignition timing of an engine by using a voltage induced in a pulsar coil or an ignition coil interlinking with a magnetic flux of a magnet rotating integrally with a flywheel. The present invention relates to an engine ignition device having a structure determined by

(Prior Art) For example, in the case of a CDI type or a transistor ignition type magneto ignition device, the ignition timing of the engine is utilized by using the voltage induced in the pulsar coil interlinking with the magnetic flux of the magnet rotating integrally with the flywheel. In the engine ignition device of the structure determined by the above, when advancing in an analog manner, voltage waveforms with different levels are generated by the pulsar coil as shown in FIG. 10, and the trigger level is set as shown by the broken line. , The delay waveform B at low speed as shown in FIG. 10 (a)
Is detected and the ignition is performed at the P1 point, and at the time of high speed, as shown in FIG. 10 (b), the method of detecting the waveform A and igniting at the P2 point is adopted.

Then, in order to obtain the waveform for the advance angle as described above, the conventional ignition device adopting, for example, the CDI method, as shown in FIG. 11, has a plurality of magnets 32 attached to the inner circumference of the flywheel 31,
A core that closely faces the magnet 32 on the inner peripheral side of the flywheel 31.
Place the exciter coil 34 with 33 and magnet
The magnetic flux of 32 is led to the outer circumference of the flywheel 31 by the iron piece 35, the pulsar coil 37 having the E-shaped core 36 is arranged on the outer circumferential side of the flywheel 31, and the exciter coil 34 and the pulsar coil 37 are connected to the igniter 38. Connect to the input end of
The output end of the igniter 38 was connected to the ignition coil 39.

On the other hand, in the engine ignition device having a structure in which the ignition timing of the engine is determined by using the voltage induced in the ignition coil that interlinks with the magnetic flux of the magnet that rotates integrally with the flywheel, as shown in FIG. The notch 42 is formed on the outer periphery of the flywheel 41, the magnet 43 is arranged in the notch 42, and the core 45 of the ignition coil 44 is closely opposed to the outer periphery of the flywheel 41. The gap between one wall surface 42a and one end surface 43a of the magnet 43 and the gap between the other wall surface 42b of the cutout portion 42 and the other end surface 43b of the magnet 43 are set to have the same size.

(Problems to be Solved by the Invention) In the above-described conventional ignition device using the pulsar coil 37, the core 36 of the pulsar coil 37 is formed in an E shape, and windings are wound on both sides of the central protruding portion of the core 36. Turning, pulsar coil
The structure of 37 was complicated. Further, the structure of the flywheel 31 is complicated, such that the magnetic flux of the magnet 32 is guided to the outer peripheral side of the flywheel 31 by the iron piece 35. From the above, the manufacturing cost was high.

As a conventional ignition device, there is, for example, one described in Japanese Utility Model Laid-Open No. 60-188874 or Japanese Patent Laid-Open No. 61-112776.

On the other hand, in the above conventional ignition device using the ignition coil 44,
As shown in FIG. 13, the magnetic flux φ interlinking with the primary winding of the ignition coil 44, the voltage e and the current i induced in the primary winding of the ignition coil 44 are the first half and the second half of one cycle. And become the same size. Moreover, the latter half of the current i used to generate the high voltage has a substantially symmetrical waveform with respect to the center line. Therefore, when igniting by advancing the current i and advancing the angle,
The relationship between the rotation speed n of the flywheel 41 and the breaking current i is
As shown in Fig. 14, the flywheel 41 rotates at low speed (rotation speed n11) compared to the cutoff current i13 or i12 at high speed (rotation speed n13) or medium speed rotation (rotation speed n12).
The cutoff current i11 at is very small. That is, the larger the advance width w, the smaller the breaking current at low speed, and the lower the ignition performance.

In order to solve this problem, for example, as disclosed in Japanese Utility Model Laid-Open No. 63-40587, it has been proposed to make the yoke of the ignition coil asymmetrical, but in this case, the cost increases. There is.

(Means for Solving the Problems) In order to solve the above problems, the engine ignition device according to the first invention links the ignition timing of the engine with the magnetic flux of a magnet provided on a ferromagnetic flywheel. In an engine ignition device having a structure that is determined by using a voltage induced in a pulsar coil, a cutout 2 having a predetermined depth is formed on a circumference of a flywheel 1 over a predetermined length in a circumferential direction, and the cutout 2 is formed. The magnet 3 is fixedly attached to the pulsar coil 4, and the core 5 of the pulsar coil 4 is formed in a U-shape and is arranged so as to open toward the center side of the flywheel. The leading side distance L11 from the front edge 2a in the rotation direction of the core 5 is longer than the distance L12 between the two projecting portions of the core 5, and the total length of the core 5 in the circumferential direction (L12 + 2L1
It is set shorter than 3) and the delay side distance L1 between the rotation direction rear end 3b of the magnet 3 and the rotation direction rear end 2b of the notch 2
By setting 4 to be shorter than the distance L12 between both protrusions of the core 5, the gap length in the first half of the interlinking period between the magnetic flux of the magnet 3 and the pulsar coil 4 is made larger than the gap length in the latter half, The magnetic resistance of the magnetic circuit formed by the air gap between the core 5 and the flywheel 1 or the magnet 3,
The leading side of the flywheel is made larger than the lagging side.

In the engine ignition device according to the second invention of the present application, the ignition timing of the engine is determined by the voltage induced in the primary winding of the ignition coil that is linked to the magnetic flux of the magnet provided in the ferromagnetic flywheel. In an ignition device for an engine having a structure which is determined by utilizing the current of the primary winding to ignite, a cutout portion 22 having a predetermined depth is formed on the outer circumference of the flyhole 1 over a predetermined length in the circumferential direction. , The magnet 23 in the notch 22
The core 25 of the ignition coil 24 is formed so as to have a U-shape, and is arranged so as to open toward the center of the flywheel. The direction of rotation of the magnet 23 is the front side edge 23a and the direction of rotation of the notch 22. The leading side distance L21 from the front edge 22a is set to
25 is longer than the distance L22 between both protrusions and shorter than the total length of the core 25 in the circumferential direction (L22 + 2L23), and the rear end edge 23b of the magnet 23 in the rotational direction and the rear side of the cutout 22 in the rotational direction are set. By setting the delay side distance L24 with the side edge 22b to be shorter than the distance L22 between both protrusions of the core 25, the air gap in the first half of the interlinking period between the magnetic flux of the magnet 23 and the ignition coil 24. The length is made larger than the air gap length in the latter half, and the magnetic resistance of the magnetic circuit formed by the air gap between the core 25 and the ferromagnetic material or magnet is set so that the leading side of the flywheel is larger than the trailing side. It was done.

(Operation) In the first invention, the magnetic resistance of the magnetic circuit is set to be larger on the leading side than on the lagging side. Therefore, the magnetic flux passing through the core of the pulsar coil is larger on the lagging side, and accordingly, the winding of the pulsar coil is larger. The voltage induced in the line is also larger on the delay side.

In the second invention, since the magnetic resistance of the magnetic circuit is set to be larger on the leading side than on the lagging side, the magnetic flux passing through the core of the ignition coil is larger on the lagging side, and therefore the primary winding of the ignition coil is formed. The current of is also larger on the delay side. That is, the breaking current becomes large.

In any of the inventions, the core of the coil is U-shaped, and by changing and adjusting the arrangement of the magnets provided in the cutout portion of the flywheel, it is possible to easily advance or delay the ignition timing to a desired timing, Cost is reduced.

(First Embodiment) An embodiment of the first invention will be described with reference to FIGS.

FIG. 1 is a configuration diagram of a main part of an engine ignition device. The flywheel 1 is made of a ferromagnetic material such as iron and rotates in the direction of an arrow α when the engine rotates. The notch 2 having a predetermined depth is formed,
A magnet 3 is fixed to the cutout portion 2 at an appropriate position. The outer circumference of the magnet 3 is located on the same cylindrical surface as the outer circumference of the flywheel 1, and a pulsar coil 4 is arranged near the outer circumference of the flywheel 1. The core 5 of the pulsar coil 4 is U-shaped, and both protrusions are located at predetermined intervals in the circumferential direction of the flywheel 1, and the tip surfaces of both protrusions are on the magnet 3 or the outer periphery of the flywheel 1. Close proximity to each other. The winding 6 wound around the core 5 of the pulsar coil 4 is connected to an igniter (not shown).

The distance L11 between one wall surface 2a of the two wall surfaces 2a, 2b in the rotational direction of the flywheel 1 of the cutout portion 2 and one end surface 3a of both end surfaces 3a, 3b of the magnet 3 in the rotational direction of the flywheel 1.
Is longer than the distance L12 between both protrusions of the core 5 and is a distance L1 obtained by adding the thickness L13 of each protrusion to the distance L12 between both protrusions.
It is set shorter than 2 + 2L13. Also, the distance L14 between the other wall surface 2b of the cutout portion 2 and the other end surface 3b of the magnet 3
Is set to be shorter than the distance L12 between both protrusions of the core 5.

Next, the operation will be described. When the flywheel 1 rotates in the direction of the arrow α and the magnet 3 reaches the vicinity of the position shown in FIG. 1,
A magnetic circuit is formed by the magnet 3, the flywheel 1, the core 5, the air gap S11 between the flywheel 1 and the core 5, and the air gap S12 between the core 5 and the magnet 3, and the magnetic flux of the magnet 3 is generated. Crosses the winding 6 through the core 5, and a voltage is induced in the winding 6 of the pulsar coil 4. Here, since the distance L11 is larger than the distance L12, it is only a part of the thickness L13 that the tip surfaces of both projecting portions of the core 5 closely face the outer periphery of the magnet 3 or the flywheel 1, and the gap S11 The substantial air gap length of S12 is larger than the distance between the facing surfaces of the tip of the protruding portion of the core 5 and the outer circumference of the magnet 3 or the flywheel 1. Therefore, since the magnetic resistance of the magnetic circuit is large, the interlinkage magnetic flux is small and the induced voltage is also small. When the flywheel 1 further rotates and reaches the vicinity of the position shown in FIG. 2, the distance L14 is shorter than the distance L12, so that the entire tip surfaces of both projecting portions of the core 5 are located on the outer periphery of the magnet 3 or the flywheel 1. The air gap lengths of the air gaps S13 and S14 are close to each other and are shorter than the substantial air gap lengths of the air gaps S11 and S12, the magnetic resistance of the magnetic circuit is reduced, and the induced voltage is increased. That is, as the flywheel 1 rotates, the magnetic flux φ11 passing through the core 5 of the pulsar coil 4 changes as shown by the solid line in FIG.
As a result, the voltage induced in the winding 6 of the pulsar coil 4
e11 changes as shown by the broken line in FIG. Ie first
As in Fig. 0 (a), a small advance waveform A and a large delay waveform B are obtained at low speed, and by setting the trigger level to the level shown by the alternate long and short dash line, the P1 point can be detected and ignited by the igniter. it can. Of course, at high speed, the advance waveform A becomes large and exceeds the trigger level, so that the advance waveform A can be detected and ignited.

In this way, the relationship between the distances L11, L12, L14 is set as described above and the gaps S11, S12 are made larger than the gaps S13, S14. Since the voltage having the waveform as shown in FIG. 3 can be obtained, it is not necessary to form the pulsar coil 37 and the flywheel 31 in a complicated shape as in the conventional case, and the manufacturing cost can be favorably reduced.

(Another embodiment) FIG. 4 shows an embodiment to which the second invention is applied, which is made of a ferromagnetic material such as iron, and is indicated by an arrow γ by the rotation of the engine.
A notch 22 having a predetermined depth is formed on the outer peripheral portion of the flywheel 21 that rotates in a predetermined direction over a predetermined length in the circumferential direction. A magnet 23 is fixed to the cutout portion 22 at an appropriate position. The outer circumference of the magnet 23 is located on the same circumferential surface as the outer circumference of the flywheel 21, and an ignition coil 24 is arranged near the outer circumference of the flywheel 21. The core 25 of the ignition coil 24 is substantially U-shaped, and both projecting portions are located at predetermined intervals in the circumferential direction of the flywheel 21, and the tip surfaces of both projecting portions are the magnet 23 or the outer periphery of the flywheel 21. Close to each other.

Rotational direction both walls 22a, 22b of the flywheel 21 of the notch 22
One of the wall surfaces 22a, the distance L21 between the two end faces 23a, 23b of the magnet 23 in the rotation direction of the flywheel 21 is longer than the distance L22 between the protrusions of the core 25. Moreover, it is set to be shorter than the distance L22 + 2L23 obtained by adding the thickness L23 of each protrusion to the distance L22 between both protrusions. Notch 22
Between the other wall surface 22b of the magnet and the other end surface 23b of the magnet 23
L24 is set shorter than the distance L22 between both protrusions of the core 25.

In this embodiment, when the flywheel 21 rotates in the direction of the arrow γ and the magnet 23 reaches the vicinity of the position shown in FIG.
23, flywheel 21, core 25, flywheel
A magnetic circuit is formed by the air gap S21 between the core 21 and the core 25 and the air gap S22 between the core 25 and the magnet 23, and the magnetic flux of the magnet 23 passes through the core 25 and the primary winding of the ignition coil 24. A voltage is induced in the primary winding of the ignition coil 24 by interlinking. Here, since the distance L21 is larger than the distance L22, it is a part of the thickness L23 that the tip surfaces of both projecting portions of the core 25 closely face the outer periphery of the magnet 23 or the flywheel 21, and the gap S21 , S22
The substantial air gap length is larger than the distance between the facing surfaces of the projecting portion of the core 25 and the magnet 23 or the outer circumference of the flywheel 21. Therefore, since the magnetic resistance of the magnetic circuit is large, the interlinkage magnetic flux is small and the induced voltage is also small. When the flywheel 21 further rotates and reaches the vicinity of the position shown in FIG. 5, the distance L24 is shorter than the distance L22, so the core 25
The entire tip surfaces of both of the protruding portions of the two closely face the outer circumference of the magnet 23 or the flywheel 21, and the gap length of the gaps S23 and S24 is the gap S
It becomes shorter than the substantial air gap length of 21, S22, the magnetic resistance of the magnetic circuit decreases, and the induced voltage increases. As a result, the current of the primary winding of the ignition coil 24 has a waveform in which the latter half of one cycle is larger than the former half, and moreover has a steep rise at the end of the latter half. Ie flywheel
The magnetic flux φ passing through the core 25 of the ignition coil 24 with the rotation of 21
31 changes as shown by the solid line in FIG. 6, whereby the voltage e31 induced in the primary winding of the ignition coil 24 changes as shown by the broken line in FIG. The current i2 of the next winding changes as shown by the alternate long and short dash line in FIG.

Therefore, when the ignition coil 24 is ignited by cutting off the current i in the primary winding of the ignition coil 24 and is advanced, a flywheel is used.
The relation between the rotation speed of 21 and the breaking current is as shown in Fig. 7,
Breaking current i23 or i22 when flywheel 21 rotates at high speed (rotation speed n23) or medium speed (rotation speed n22)
Comparing with, breaking current i at low speed rotation (rotation speed n21)
21 does not become smaller than in the case of the conventional device shown in FIG.
That is, even if the advance angle width w1 is increased, the breaking current at low speed does not become so small, and the ignition performance does not deteriorate.

In this embodiment, when the breaking current at low speed is the same as that of the conventional device shown in FIG. 12, the advance width w2 is significantly larger than the advance width w1 of the conventional device as shown in FIG.

Further, in this embodiment, the three-needle spark gap showing the ignition performance is improved as shown in FIG. 9 (A), and the ignition timing showing the advance angle performance is also shown in FIG. 9 ( It improves like B). In FIG. 9, the case of this embodiment is shown by a solid line, and the case of the conventional device is shown by a broken line.

In this way, the relationship between the distances L21, L22, L24 is set as described above, and the gaps S21, S22 are made larger than the gaps S23, S24. Since the current i2 having the waveform as shown by the one-dot chain line can be obtained, the ignition performance at low speed can be secured without the asymmetric special shape of the yoke of the ignition coil unlike the conventional case, and therefore the manufacturing cost is good. Can be reduced to

Although the flywheels 1 and 21 made of a ferromagnetic material are used in each of the above-described embodiments, the present invention is not limited to such a configuration, and the ferromagnetic material forming the magnetic path is made to the flywheel 1 , 21 may be fixed.

(Effect of Device) As described above, the first device is the ignition device including the pulsar coil 4 having the U-shaped core 5, and the relationship between the distances and the dimensions (L11, L12, L13, L14) described above. Are set to a predetermined relationship, the voids S11, S12 in the first half of the interlinking period shown in FIG. 1 are changed to the voids S13, S in the latter half of the interlinking period shown in FIG.
It can be greater than 14, which makes it easier
At the time of low speed, the pulsar coil 4 has a third No. 3 similar to Fig.
The voltage having the waveform as shown in the figure can be obtained, and it is not necessary to form the pulser coil and the flywheel in a complicated shape as in the conventional case, and the manufacturing cost can be favorably reduced.

The second invention is a structure in which energy is stored and signals are performed by the same primary winding of the ignition coil 24, and the U-shaped core 25 is provided as the core 25 of the ignition coil 24. By setting the relationship between each dimension L22, L23 of the core 25 and the air gap distances L21, L24, etc. on both front and rear sides of the magnet 23 to a predetermined relationship, the air gap in the first half of the interlinking period shown in FIG.
It is possible to make S21 and S22 larger than the air gaps S23 and S24 in the latter half of the interlinking period shown in FIG. 5, so that the primary winding of the ignition coil 24 can easily be indicated by the one-dot chain line in FIG. 6 at low speed. It is possible to obtain the current i2 having a waveform as shown in (3), and it is possible to secure the ignition performance at low speeds without making the yoke of the ignition coil asymmetrical and have a special shape as in the conventional case. Therefore, the manufacturing cost can be favorably reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an engine ignition device according to an embodiment of the present invention, FIG. 2 is an operation explanatory diagram of the ignition device, and FIG. 3 is a magnetic flux passing through a core of a pulsar coil of the ignition device and FIG. 4 is a waveform diagram of the voltage induced in the winding, FIG. 4 is a configuration diagram of a main part of an engine ignition device in another embodiment, FIG. 5 is an operation explanatory diagram of the ignition device, and FIG. 6 is the ignition device. Of the voltage and current induced in the magnetic flux passing through the core of the ignition coil and in the primary winding of the ignition coil, FIG. 7 is an explanatory view of the relationship between the breaking current and the advance width of the ignition device, and FIG. FIG. 9 is an explanatory view of an advance angle width in comparison with the conventional device of the ignition device, FIG. 9 (A) is an explanatory view of a three-needle spark gap in comparison with the conventional device of the ignition device, and FIG. 9 (B). Is an explanatory diagram of the ignition timing in comparison with the conventional ignition device, and FIG. 10 is a pulser of the conventional ignition device. Waveform diagram of the voltage induced in yl, first
FIG. 11 is an overall configuration diagram of the ignition device, FIG. 12 is a configuration diagram of a main part of another conventional ignition device, and FIG. 13 is a magnetic flux passing through a core of the ignition coil of the ignition device and a primary winding of the ignition coil. FIG. 14 is a waveform diagram of the voltage and current induced in the line, and FIG. 14 is an explanatory diagram of the relationship between the breaking current and the advance width of the ignition device. 1,21 ...... flywheel (ferromagnetic material), 3,23 ... magnet,
4 ... Pulsar coil, 5,25 ... Core, 24 ... Ignition coil

Claims (2)

[Scope of utility model registration request] 1. An engine ignition device having a structure for determining an engine ignition timing by utilizing a voltage induced in a pulsar coil interlinking with a magnetic flux of a magnet provided on a ferromagnetic flywheel. On the outer circumference of the hole (1),
A notch (2) having a predetermined depth is formed over a predetermined length in the circumferential direction, a magnet (3) is fixed to the notch (2), and a core (5) of a pulsar coil (4) is formed into a U-shape. And is arranged so as to open toward the center side of the flywheel, and the front edge (3a) of the magnet (3) in the rotational direction and the front edge (2a) of the notch (2) in the rotational direction are formed. The leading side distance (L11) is longer than the distance (L12) between both protrusions of the core 5, and the total length of the core (5) in the circumferential direction (L12 + 2L1
Set shorter than 3), the delay side distance (L14) between the rotation direction rear side edge (3b) of the magnet (3) and the rotation direction rear side edge (2b) of the notch (2), By setting the gap shorter than the distance (L12) between both protrusions of the core (5), the gap length in the first half of the interlinking period of the magnet (3) with the magnetic flux pulsar coil (4) is set to be smaller than the gap length in the latter half. The magnetic resistance of the magnetic circuit formed by the air gap between the core (5) and the flywheel (1) or the magnet (3) is made larger on the leading side of the flywheel than on the lagging side. An engine ignition device characterized by the above. 2. An ignition timing of an engine is determined by using a voltage induced in a primary winding of an ignition coil interlinking with a magnetic flux of a magnet provided on a ferromagnetic flywheel, and the primary winding is determined. In an engine ignition device having a structure in which ignition is performed by interrupting a line current, a cutout portion (22) having a predetermined depth is formed on a periphery of a flywheel (1) over a predetermined length in a circumferential direction, and the cutout portion (22) is formed. The magnet (23) is fixed to the (22), the core (25) of the ignition coil (24) is formed in a U shape and is arranged so as to open toward the center side of the flywheel, and the magnet (23) rotates. Distance (L21) between the front edge (23a) in the front direction and the front edge (22a) in the rotational direction of the notch (22)
Is longer than the distance (L22) between both protrusions of the core (25), and is the total circumferential length of the core (25) (L22 + 2L2
Set it shorter than 3), and set the delay side distance (L24) between the rotation direction rear edge (23b) of the magnet (23) and the rotation direction rear edge (22b) of the notch (22), By setting the core (25) shorter than the distance (L22) between both protrusions, the magnet (2
The air gap length in the first half of the interlinking period between the magnetic flux of 3) and the ignition coil (24) is made larger than the air gap length in the second half,
Ignition of an engine characterized in that the magnetic resistance of a magnetic circuit formed by the air gap between the core (25) and the ferromagnetic material or magnet is set so that the leading side of the flywheel is larger than the trailing side. apparatus.