Patent Publication Number: US-5024185-A

Title: Ignition distributor of internal combustion engine

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an ignition distributor for an internal combustion engine (hereinafter referred to simply as distributor) and more particularly to the electrically connecting structure, in relation to the outside, of an electrical device housed in the distributor. 
     2. Description of the Related Art 
     Distributors containing such units as an ignition coil and an igniter within their housings are well known. FIGS. 1 and 2 are a vertical sectional view and a horizontal sectional view, showing structures of a section extending a lead wire in such conventional distributors for internal combustion engines. An ignition coil 2 and an igniter 3 are housed in a housing 1. Although not shown, a shaft rotating synchronously with the crankshaft rotation of the internal combustion engine is inserted and supported rotatably by a bearing in the housing. Further, a sensor device for detecting the angle of a crank is included so that a detecting signal is obtained by the rotation of the shaft. 
     The ignition coil 2 comprises a coil winding 21 of the primary side, a terminal 22, a lead wire 23 connecting the end of the coil winding 21 to the terminal 22 and a molded material 24 for embracing the above components and maintaining electric insulation. A coil winding of the secondary side is not shown. Two lead wires 6 consisting of flexible wires 6a and 6b run through a rubber bushing 5 in close proximity to the fitting section of the housing 1 for a distributor cap 4. Connecting pieces 62a, 62b are electrically connected and fixed to the flexible wires 6a and 6b by crimp-style terminals 61a, 61b within the housing 1. One end of the connecting piece 62 mates the terminal 22 of the ignition coil 2, making electrical connection to the coil winding 21. Although not shown in Figs., an electrically connected lead wire 63 through a crimp style terminal 61c is connected to the igniter 3. The lead wire 6 is provided with a connector 7 on the end thereof and the connector is fixed on the periphery of the housing 1 (not shown). 
     In a structure of the conventional distributor as described above, when assembling, the ignition coil 2 is housed in the housing 1, whereas the lead wire 6 is run through the rubber bushing 5 and then the connector 7 is fixed on one end of the wire 6 and the connecting piece 62 is fixed through the crimp-style terminal 61 on the other end of the wire 6. A connection is made by connecting the connecting pieces 62a and 62b to the terminals 22 of the ignition coil 2 as well as fixing the rubber bushing 5 to the housing 1. 
     The conventional distributor as constructed above has the following problems, that is, since the winding and the like of the ignition coil 2 are extended with the aid of the flexible lead wire 6, three crimp-style terminals are required, resulting in not only complicated and time-consuming assembly but many parts and increase in cost. 
     SUMMARY OF THE INVENTION 
     This invention overcomes the above described problems. It is therefore an object of the present invention to provide a distributor with simple assembly and fewer parts and which is not expensive. 
     In light of the above object, this invention is an ignition distributor of the internal combustion engine comprising: 
     a housing surrounding a shaft rotated synchronously with the crankshaft rotation of said engine, said housing containing at least one electrical device including terminals for an ignition coil, an igniter, a detector for rotation angle and the like; 
     through hole means provided on said housing for electrically connecting said electrical device to the outside of said housing; and 
     leading means including at least one connecting section connected electrically to said electrical device, a connector section arranged in said through hole means defined on said housing, a lead wire section connecting electrically said connecting section and said connector section, and a mold section defined as an integral part rigidly by molding of said connecting section, said connector section and said lead wire section together with or without at least one of said electrical devices. 
     The distributor according to this invention includes the leading means where an electrical connection between the electrical device housed in the housing and an external device is made. That is, the connecting section arranged on the terminal of the electrical device is electrically interconnected in the leading means to the connector section arranged in the through hole means within the housing. The leading means is also rigidly defined by molding to embrace the above components as well as the electrical device itself as a whole. 
    
    
     These and other objects of the invention will become apparent by reference to the Description of the Preferred Embodiment, taken in connection with accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a vertical sectional view showing the main structure of the subject portion of the conventional distributor; 
     FIG. 2 is a horizontal sectional view illustrating the major components of the distributor of FIG. 1; 
     FIG. 3 is a vertical sectional view showing the subject structure of the distributor according to an embodiment of this invention; 
     FIG. 4 is a horizontal sectional view depicting the major components of the distributor shown in FIG. 3; 
     FIG. 5 is a plan view showing the inside of another conventional distributor; 
     FIG. 6 is a plan view illustrating the distributor with the distributor head thereof removed according to another embodiment; and 
     FIG. 7 is a sectional side view showing the major components of the embodiment shown in FIG. 6. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will be hereinafter described with reference to the drawings. As shown in FIGS. 3 and 4, the ignition coil 2 is arranged, as an integral part, so that the molded material 24 encircling the cold winding 21 includes a connector section 25. A contacting piece 26 is already embedded in the connector section 25. The end of the contacting piece 26 is connected to the coil winding 21 via the lead wire 23 before molding. The lead wire 23 is therefore embedded in the mold material 24 as a part thereof. The housing 1 is further provided with through hole means 11 to extend the coil winding of the ignition coil 2 and the like out of the housing 1 so that the connector section 25 runs through the through hole means 11 and one part thereof farther projects therefrom. The explanations of the other reference characters are omitted because they are the same as those shown in FIGS. 1 and 2. 
     An integral formation of the connector section 25 and the coil winding 21 according to this invention as constructed above decreases connecting points of a crimp-style terminal and extremely simplifies assembling and connecting operations. As a result of the above, only one crimp-style terminal demanding time and effort is enough as shown in FIG. 4. Further, since the connector section 25 is directly fixed to the housing 1, it is not necessary to extend the connector out of the housing 1 to fix it at an appointed location. The effect of the invention in practical use is extremely remarkable. An inexpensive and highly reliable distributor is consequently available. 
     Although the connector 25 is projected outside of the housing 1, it may be arranged to any locations as desired. For example, the connector may be disposed backward toward the housing 1 so that the end portion 25a of the connector section 25 substantially meets the periphery of the housing 1. It is also expected to achieve the same effect as the above embodiment in the case where a sensor for detecting rotation and an igniter are not contained in the housing 1. The crimp-style terminal 61 is not always required. Further, connecting methods and the number of contacting pieces are not limited to the above described embodiment. 
     As described above, according to the aforementioned embodiment, the housing is provided with the through hole means and defined as an integral part by the molding together with the connector section to electrically connect the ignition coil and an external circuit. Owing to the construction of the connector section arranged in the through hole section, the distributor with fewer parts, simpler assembly and inexpensive in production is available. 
     FIG. 5, for example, illustrates the inside of another conventional distributor shown in &#34;Structure of Automobile Electrical Equipment&#34;, by The Association of All Japan Automobile Maintenance and Repair Schools, Sankaido Company, the First Impression of the Revised edition, Mar. 30, 1988. An overall description for FIG. 5 is omitted. Within the housing 101, an electrical device 109 serving as a magnetic detector including a magnet 191, a pick-up coil 192, etc. for rotation angle are arranged in an opposite direction to a timing rotor 107 rotating with the same axis as a shaft 102. The output signal of the pick-up coil 192 is led out of the housing 101 through leading means 110. The leading means 110 include a protective tube 104 and a flexible conductor 111, and one end thereof is connected to a terminal 193 and the other to a connector section 112 to which the flexible conductor 111 is connected through the protective tube 104. Although not shown, other electrical devices such as an igniter, an ignition coil, etc. are arranged in the housing 101. 
     The conventional distributor as constructed above has, for example, the following problems: the use of the flexible conductor 111 as the extending means 110 may swing and is not rigid within the housing 101, resulting in a crack, disconnection and so on by interference with other parts. Because of many parts, it takes time to thrust lead wires to various electrical devices. 
     In the distributor of another embodiment according to the present invention, through hole means as well as leading means having the through hole means through which a connector section is defined is arranged in the housing. The section including from the connector section and the terminal of the electrical device is defined, as an integral part, by molding. Thus, the whole components are rigidly fixed, simplified in assembly and less interfered with other parts. 
     Another embodiment of this invention will be described in connection with drawings. As shown in the embodiment of FIGS. 6 and 7, the housing 101 contains a second electrical device 109B having an igniter and a third electrical device 109C (see FIG. 7) having an ignition coil, other than a first electrical device 109A having magnetic detector with a magnet (not shown), a pick-up coil 192A and the like for rotation angle. The output terminal 193A of the pick-up coil 192A is electrically connected to the input terminal 195B of an igniter 109B. The leading means 110 are so arranged that one end thereof is connected to a connecting section 113B for the output terminal 193B of the igniter 109B and a connecting section 113C for the terminal 193C of the ignition coil 109C is arranged at the center of the leading means 110 (see FIG. 7). A connecter 112 fixed to through hole means 101a of the housing 101 is disposed at the other end of the leading means. The space between the ends of the means is shaped as a whole by molded coating from molding. The through hole means 101a is an opening formed in an engagement portion where the housing 101 and the distributor cap mate. When assembling, only by fixing the leading section 110 downward as shown in FIG. 7, mating the connector section 112 with the through hole means 101a and the connecting section 113C for the terminal 193C on the ignition coil 109C is allowed, a location for the connection section 113B for the terminal 193B on the igniter 109B is determined. The connecting section 113B is then fixed by fixing means such as a screw to the terminal 193B. The terminal 193C on the ignition coil 109C is connected by spring force to the connecting section 113C (not shown). Further, it is needless to say that the conductor is appropriately connected or branched within the extending means. 
     As is clear from the description of the above structure, in this embodiment, when assembling, the leading means 110 is fitted to the through hole means 101a, while mating simultaneously the connecting section 113C with the terminal 193C so that the location for the terminal 193B automatically corresponds to that of the connecting section 113B. The connecting section 113B and the terminal 193B are then fixed by such means as a screw. This completes the connection. Therefore, easy assembling is made, giving an advantage of assembly automation. Since the conductor connecting the connector section 112 and the terminals 193B, 193C is rigidly constructed by the molded coating 114 of an insulating material, it resists vibration and interferes less with other parts, thereby preventing such problems as a crack and disconnection of the leading means. As a consequence, a highly reliable distributor is available. 
     The description is made in the above embodiment for housing 101 containing three electrical devices 109A, 109B and 109C having the detector for rotation, the igniter and the ignition coil. The embodiment, however, is not limited to the above scope. The same effect of the embodiment as described above will be achieved, provided that the housing contains suitable one or more electrical device. That is, the leading means 110 do not necessarily have two connecting sections 113B, 113C and accepts one or more than two. Although the through hole means 101a is arranged in the concave location of the housing 101, the location may be provided on booth the housing 101 and the distributor cap 120. 
     As described in the embodiments shown in FIGS. 6 and 7, the leading means are arranged where one end thereof is the connecting section electrically connected to the terminal of the electrical device and the other end thereof is the connector section arranged in the through hole means of the housing. The leading means are so constructed as to form these ends by molded shaping as an integral part, resulting in unnecessary extension of lead wire, less interference with other parts and elimination of such problems as a crack and disconnection. It is therefore possible to provide a highly reliable and easy-to-manufacture distributor.