The present invention relates to a structure of a high frequency discharge ignition apparatus that is mainly used in an internal combustion engine.
In recent years, issues such as environment preservation and fuel depletion have been raised, and measures for these issues should be urgently taken also in the automobile industry. As example of such measures, there is a method for improving fuel consumption through engine downsizing by use of a supercharger.
However, it is known that in a high-supercharge state, the pressure in an engine combustion chamber becomes very high even when no combustion occurs, which makes it difficult to produce a spark discharge for starting combustion. In order to solve this problem, it is necessary to narrow the gap interval in an ignition plug to increase the withstand voltage. However, if the gap of the ignition plug is narrowed, the influence of the extinguishing action by electrode portions becomes large in turn, which causes problems such as reduced startability and reduced combustion performance.
In order to solve this problem, means is conceivable in which energy exceeding the extinguishing action, i.e., exceeding thermal energy absorbed by the electrode portions, is provided through spark discharge. For example, a high frequency discharge ignition apparatus as disclosed in Patent Document 1 has been proposed.
The high frequency discharge ignition apparatus disclosed in Patent Document 1 causes a conventional ignition coil to produce a spark discharge in an ignition plug gap, and puts a stable and desired high frequency energy in the path of the spark discharge via a coupling circuit formed by a capacitor, thereby enabling a high-energy spark discharge and production of discharge plasma that spreads wider than an ordinary spark discharge.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2015-78666
The present invention has been made in order to solve the problem regarding the configuration of the above-described conventional apparatus. An object of the present invention is to provide, in a small space, a high frequency discharge ignition apparatus having a structure which suppresses noise occurring from the entirety of the loop in which high frequency energy is conducted, thereby suppressing influence to peripheral devices.
A high frequency discharge ignition apparatus according to the present invention is a high frequency discharge ignition apparatus for coupling high frequency energy supplied from a high frequency energy supply circuit, with a high voltage pulse supplied from an ignition coil, and supplying the coupled energy to an ignition plug, the high frequency discharge ignition apparatus including: a first housing having therein an output circuit for supplying the coupled energy to the ignition plug; a second housing having therein the high frequency energy supply circuit; and a connection member electrically connecting the output circuit and the high frequency energy supply circuit to each other, wherein the first housing and the second housing are fixed to each other with faces thereof opposed to each other, and the connection member is connected via pass-through portions provided at positions that are close to each other in the respective opposed faces.
According to the high frequency discharge ignition apparatus of the present invention, the length of the loop in which high frequency energy is conducted is reduced, whereby noise can be reduced.
Hereinafter, an embodiment of a high frequency discharge ignition apparatus in the present invention will be described with reference to the drawings. In the drawings, the same or equivalent portions are denoted by the same reference characters.
In the present embodiment, it is assumed that the voltage of “high voltage pulse” is 30 to 40 kV, the voltage of “high frequency energy” is 1 to 2 kV, and the frequency of “high frequency” is several hundred kHz to several MHz.
First, functions of elements of the high frequency discharge ignition apparatus in the present embodiment 1 shown in
The electronic circuit board 3 includes, on the printed circuit board thereof, electronic components 4 forming a high frequency energy circuit, such as an input/output circuit, a control circuit, a microcomputer, and a power supply circuit.
Each of the first housing 12 and the second housing is formed of aluminium, stainless steel, PBT resin, or the like, for example. However, the material of the first housing 12 and the second housing 15 is not limited thereto. One side 33 of the terminal 7 is inserted into the through hole 21 in the electronic circuit board 3, and is electrically connected and fixed to a circuit (not shown) such as an input/output portion of the electronic circuit board 3. The other side of the terminal 7 is electrically connected to the electronic component 8.
The terminal member 10 is used for providing connection between an ignition coil (not shown) and the terminal member 9, the terminal member 11 is used for providing connection between an ignition plug (not shown) and the terminal member 9, and the terminal member 9 is used for providing connection among the terminal members 10 and 11 and the electronic component 8.
Next, the procedure of assembling the high frequency discharge ignition apparatus in the present embodiment 1 will be described.
In the present embodiment, it is assumed that the base area of the base 5 of the second housing 15 is greater than or equivalent to the base area of the first housing 12.
In addition, in the present embodiment, a high frequency discharge ignition apparatus is assumed in which, for example, by the protector 14 being mounted to an ignition plug 40, a coupling circuit and the ignition plug 40 are directly connected to each other as shown in
First, the fit portions 25 of the electronic component 8 are mounted to the fit portions 23 of the terminal 7, thereby fixing the electronic component 8 and the terminal 7 together. Then, a metal terminal portion 29 of the electronic component 8 and the other side 30 of the terminal 7 are welded together to be electrically connected to each other (see
As a result, positioning of the electronic component 8 relative to the terminal 7 is realized.
It is noted that the connection between the metal terminal portion 29 of the electronic component 8 and the other side 30 of the terminal 7 may be provided by soldering.
Next, the crush ribs 16 inside the first housing 12 are fitted in the holding portions 22 of the terminal 7 (see
As a result, relative positioning of the terminal 7 relative to the through hole 21 of the electronic circuit board 3 is realized.
Next, the terminal member 11 is inserted into the fit portion 17 of the first housing 12 (see
In addition, the terminal member 9 and the terminal member 11 are fitted at the fit portion 27, and further, the terminal member 9 and the electronic component 8 are electrically connected to each other at the fit portion 26 (see
The terminal member 10 is inserted into the fit portion 18 of the first housing 12, and further, one side 31 of the terminal member 10 is fitted in the fit portion 28 of the terminal member 9, whereby the terminal member 9 and the terminal member 10 are electrically connected to each other (see
It is noted that the connection between the one side 31 of the terminal member 10 and the fit portion 28 of the terminal member 9 may be provided by press fit, welding, or soldering.
Then, in a state where the components are assembled together, a cast resin 32 is poured into the first housing 12 (see
Next, the packing 6 is inserted in the groove portion 24 of the terminal 7 (see
Then, the one side 33 of the terminal 7 is inserted in the opening 20 in the base 5 (see
At the same time when the one side 33 of the terminal 7 is inserted in the opening 20 in the base, a protruding portion 19 provided on a flange 34 of the first housing 12 and a groove portion 36 provided in a boss 35 on the base 5 are fitted together (see
As a result, positioning between the flange 34 of the first housing 12 and the boss 35 of the base 5 are realized.
Next, the flanges 34 of the first housing 12 and screw holes 37 provided in the bosses 35 of the base 5 are fastened together by means of screws or bolts 13 via the flanges 34. In addition, the protector 14 is fitted to a fit portion 38 of the first housing 12 (see
It is noted that either one of the first housing 12 and the second housing 15 may be provided with two or more flanges, and the other one of the first housing 12 and the second housing 15 may be provided with screw holes at positions corresponding to the flanges.
As a result, waterproofing between the first housing 12 and the second housing 15 is realized.
Further, the one side 33 of the terminal 7 protruding from the opening 20 in the base 5 is fitted into the through hole 21 in the electronic circuit board 3, thereby providing electrical connection therebetween (see
As a result, positioning of the terminal 7 is determined such that the first housing 12 is disposed so as not to protrude beyond the base area range of the metal base of the second housing 15, which has a larger base area. Here, in order to improve earthquake resistance, the electronic circuit board 3 and the base 5 may be screwed to be fixed to each other.
Lastly, the cover 1 is mounted to the base 5 (see
By performing the assembly as above, a structure is obtained in which: connection between a high frequency energy supply circuit 103 and a coupling circuit 104 is realized by means of a terminal; and the housing having therein the high frequency energy supply circuit 103 and the housing having therein the coupling circuit 104 are integrated. Accordingly, the entirety of the apparatus can be downsized. In addition, since the length of the loop 201 in which high frequency energy is conducted is reduced, noise occurring from the loop can be reduced (see
Furthermore, since the loop is shortened, the range to provide shielding in the entirety of the apparatus can be reduced, and thus, it becomes easy to take measures against noise.
When the second housing 15 requires waterproof property, the mating face between the cover 1 and the base 5 may be sealed with a sealant, a packing, or the like.
Hereinafter, described are the steps of assembling the high frequency discharge ignition apparatus of embodiment 1 to a fastening target body 39 which is made of metal and which is assumed as an engine block shown in
First, the ignition plug 40 is assembled to the fastening target body 39 (see
Then, the protector 14 is mounted to the ignition plug 40. As a result, the coupling circuit and the ignition plug 40 are directly connected to each other.
It is assumed that, a peripheral portion of the cover 1 is provided with at least three flange holes 41, and that the fastening target body 39 is provided with at least three fastening portions 42 corresponding to the flange holes 41 of the cover 1.
Then, the ignition apparatus of the present invention may be fastened with screws or bolts 43 via the flange holes 41 to the fastening portions 42 of the fastening target body 39 (see
In this manner, by the first housing 12 being disposed inside a space 44 formed by the flanges of the second housing 15 and the fastening portions 42 of the fastening target body 39, radiation noise occurring from the output circuit can be suppressed (see
As described above, embodiment 1 employs the configuration in which: as shown in
As a result, the length of the loop in which high frequency energy is conducted is reduced, whereby noise occurring from the loop can be reduced, and the entirety of the apparatus can be downsized. Further, since the range to provide shielding in the entirety of the apparatus can be reduced, it becomes easy to take measures against noise.
In embodiment 1 above, the packing 6 is inserted or an adhesive is used in the groove portion 24 in a resin material multiple molded portion of the terminal 7, whereby waterproofing with the base 5 is realized. However, instead of the resin material multiple molded portion of the terminal 7, a lid 45 may be used to ensure waterproofing with the base 5.
The lid 45 includes: on the outer face thereof, a groove portion 46 and a fit portion 47 for fitting the lid 45 the terminal 7 to each other; and on the rear face of the lid 45, a protrusion 48 having a height that allows the protrusion 48 to be immersed in the cast resin 32 (see
As in embodiment 1 above, the first housing 12 and the lid 45 may be fixed to each other by means of the cast resin 32, after the components up to the terminal member 10 have been assembled to the first housing 12 (see
For realizing waterproofing between the lid 45 and the base 5, the packing 6 may be inserted or an adhesive may be used in the groove portion 46 provided in the lid 45.
As described above, embodiment 2 has a structure that realizes a waterproofing mode different from that in embodiment 1, and the lid 45 for waterproofing is fixed together with the first housing 12 by means of the cast resin 32, whereby entry of water from outside can be prevented.
In embodiment 1 above, as shown in
For example, as shown in
Thus, the structure according to embodiment 3 makes it possible to provide electric connection even for a circuit that does not use a circuit board.
In embodiment 1 above, as shown in
For example, as shown in
Thus, in the structure according to embodiment 4, the terminal 52 is caused to protrude from the second housing 15, to be fitted into the first housing 12, thereby making it possible to provide electric connection.
In embodiment 1 above, as shown in
In embodiment 1 above, as shown in
In embodiment 1 above, as shown in
Accordingly, in embodiment 7, the entirety of the first housing 12 is covered by a metal body, and thus, noise reduction effect is higher than in embodiment 1.
Further, when it is difficult to provide the protrusion 62 to the fastening target body 60 of embodiment 7, a metal component 63 as shown in
Accordingly, the structure of embodiment 8 realizes higher noise reduction effect than embodiment 1.
It is noted that, within the scope of the present invention, the above embodiments may be freely combined with each other, or each of the above embodiments may be modified or simplified as appropriate.
Number | Date | Country | Kind |
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2016-076988 | Apr 2016 | JP | national |
Number | Name | Date | Kind |
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4483423 | Renzelmann | Nov 1984 | A |
20020017271 | Suckewer | Feb 2002 | A1 |
20140299085 | Ikeda | Oct 2014 | A1 |
20150108914 | Muramoto et al. | Apr 2015 | A1 |
20160341170 | Ota | Nov 2016 | A1 |
Number | Date | Country |
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2015-078666 | Apr 2015 | JP |
Entry |
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Communication dated Mar. 14, 2017, issued from the Japan Patent Office in counterpart Japanese Patent Application No. 2016-076988. |
Number | Date | Country | |
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20170294764 A1 | Oct 2017 | US |