JP3158820B2 - Ignition coil device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition coil device for an internal combustion engine, and more particularly to an ignition coil device for an internal combustion engine having a terminal to which an end wire of a coil wound on a bobbin is connected.

[0002]

2. Description of the Related Art As an internal combustion engine, a spark ignition type engine is known. This spark ignition type engine is provided with an ignition coil device for an internal combustion engine (hereinafter, referred to as an ignition coil device) in order to discharge an electric spark to a spark plug.
This ignition coil device has a small number of coil turns (for example,
(200 to 500 times) A primary coil and a secondary coil having a large number of coil turns (for example, 15,000 to 25000 times) are provided, and each of the coils is mounted in a case. Then, a high-voltage current is generated in the secondary coil by appropriately controlling the passage point time of the primary coil current and the cutoff timing of the current.

The primary coil and the secondary coil have a structure in which a coil wire is wound around a coil bobbin, and the coil bobbin is formed with a pair of terminals to which the ends of the coil wire are connected. To wind a coil wire around the coil bobbin, first connect one end of the coil wire to one terminal and connect it. Then, wind the coil wire a predetermined number of times around the coil bobbin. Connect the other end of the cable to the other terminal.

[0004] This winding operation is performed by using a coil winding device. Since the coil winding device performs a winding process by applying a constant tension to a coil wire, the coil winding device is provided near a tangled portion with a terminal. The end line is in a state having tension, in other words, in a state without slack. If each of the coils is mounted in the case with the end line having no slack, disconnection may occur at the end line.

[0005] That is, the ignition coil device mounted on a vehicle is placed in a severe environment, and needs to be configured to withstand a temperature change from -20 ° C to + 200 ° C. On the other hand, the bobbin around which the coil is wound is made of resin and has a high coefficient of thermal expansion, and the terminal is made of metal and has a lower coefficient of thermal expansion than the bobbin. A difference in expansion occurs, which may cause disconnection at the end line portion.

As a prior art for preventing a disconnection at the end line portion, for example, Japanese Patent Laid-Open Publication No.
No. 0 discloses this. The means for preventing the disconnection of the end line portion disclosed in the publication discloses a method in which the end line 42 is entangled with the terminal 41 as shown in FIG. 4A, and then the terminal 41 is bent as shown in FIG. Thus, the end line 42 is configured to have slack.

[0007]

However, the prior art disclosed in the above publication has a problem in that the number of operations for bending the terminal 41 in the assembling operation of the ignition coil device is increased, and the assembling operation is troublesome.

When bending the terminal 41,
In the conventional configuration, since the terminal 41 is configured to bend substantially at a substantially right angle, the end line 42 may be disengaged from the terminal 41, thereby causing a problem that the reliability of the ignition coil device is reduced.

As described above, the terminal 41 is an external connection terminal (not shown in FIG. 4) formed in the case.
Terminal 4 that needs to be connected to
In order to connect 1 to an external connection terminal, it is necessary to accurately determine the bending angle of the terminal 41. That is, when the bending angle is folded more than a predetermined angle, the Terminal
There is a possibility that the null 41 and the external connection terminal are separated from each other so that conduction cannot be achieved. For this reason, there is a problem that the bending operation of the terminal 41 requires precision, and this also complicates the assembling operation.

Further, since the above-described bobbin is configured to be simply inserted and mounted in the case, there is a problem that the bobbin rattles in the case or the bobbin detaches from the case in some cases. Was.

The present invention has been made in view of the above points, and provides an ignition coil device for an internal combustion engine capable of securely connecting a terminal to an end line and preventing a bobbin from being detached from a case. With the goal.

[0012]

According to the present invention, a bobbin around which a coil for igniting an internal combustion engine is wound is connected to an end line of the coil provided on the bobbin. In the ignition coil device for an internal combustion engine constituted by a terminal having a terminal and a case to which the bobbin is mounted, the terminal is formed of an elastically deformable member.
With the end line of the bobbin being tensioned.
The bobbin's terminal
Dimensions that include the
The terminal is urged by the case and elastically deforms in a state where the bobbin is mounted on the case, thereby forming a slack in the end line.

[0013]

With the above configuration of the ignition coil device for an internal combustion engine, when the bobbin is mounted on the case, the terminal is urged by the case and deformed, so that the end line connected to the terminal has slack. Can be.

Further, since the amount of elastic deformation of the terminal is set to a value that can maintain the elastic restoring force, the amount of deformation is smaller than the amount of deformation that is conventionally bent at a substantially right angle. It is possible to reliably prevent the line from coming off the terminal.

Further, with the bobbin attached to the case,
Since the terminal presses the case with an elastic restoring force accompanying the elastic deformation, the pressing force functions as a holding force for holding the bobbin to the case, so that the bobbin can be prevented from falling off the case.

[0016]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is an exploded perspective view of an ignition coil device 1 (hereinafter, referred to as an ignition coil device) for an internal combustion engine according to one embodiment of the present invention. The ignition coil device 1 generally includes a bobbin for a primary coil 2, a bobbin for a secondary coil 3, a case 4
And the like.

The primary coil bobbin 2 is made of, for example, a thermoplastic resin, and a relatively thick coil wire (not shown) is wound, for example, 200 to 500 times to form a primary coil. . The end of the coil wire wound around the primary coil bobbin 2 is connected to a low voltage side external connection terminal (not shown).

The bobbin 3 for the secondary coil has a coil wire 5 (appearing in FIG. 1), such as an enamel wire, which is thinner than the coil wire wound around the bobbin 2 for the primary coil.
It has a configuration of 5,000 to 25,000 turns. The secondary coil bobbin 3 is also made of a thermoplastic resin like the primary coil bobbin 2, and has a structure in which a plurality of fins 6 are formed in order to improve heat radiation efficiency.

Further, the bobbin 3 for the secondary coil has an insertion hole 7
Is formed, and the primary coil bobbin 2 is mounted in the insertion hole 7 formed in the secondary coil bobbin 3.
As a result, the primary coil bobbin 2 and the secondary coil bobbin 3 are electromagnetically connected.

On the other hand, on both sides of the secondary coil bobbin 3, terminals 8a and 8b are implanted by insert molding or the like, respectively. Each of the terminals 8a and 8b is made of a metal material (for example, an aluminum alloy or the like) having conductivity and capable of elastic deformation. Each of the terminals 8a and 8b is bent and formed in a substantially rectangular shape.
The shape is such that elastic deformation is easily performed. Both end lines 5a and 5b of coil wire 5 wound around secondary coil bobbin 3
Are fixedly connected to the terminals 8a and 8b, whereby the coil wire 5 is electrically connected to the terminals 8a and 8b.

Here, a method of winding the coil wire 5 around the secondary coil bobbin 3 will be briefly described. In order to wind the coil wire 5 around the bobbin 3 for the secondary coil, first, one end line 5a of the coil wire 5 is connected and fixed to one terminal 8a, and then the coil wire 5 is wound around the bobbin 3 for the secondary coil. 5
Is wound a predetermined number of times. After winding a predetermined number of turns, the other end line 5b of the coil wire 5 is connected to the other terminal 8
b.

This winding operation is performed using a coil winding device. As described above, the coil winding device
In order to carry out the winding process with a constant tension, the end lines 5a and 5b are entangled with the terminals 8a and 8b, and the end lines 5a and 5b are in a tensioned state even in the vicinity of the cramped portion.
In other words, there is no slack.

Next, case 4 will be described. The case 4 is a bottomed container formed of a hard resin, and has two high-pressure external connection portions 9a and 9b formed on side portions thereof. As shown in FIG. 3, the high-voltage external connection portions 9a and 9b are connected to high-voltage external connection terminals 11a and 11b (in FIG. 3, one high-voltage external connection terminal). (Only the connection terminal 11a is shown). The above-mentioned terminals 8a, 8b are connected to the inner ends 11a- ₁ and 11b- ₁ of the high-voltage external connection terminals 11a and 11b.
And connection cables (not shown) to the distributor are connected to the outer terminal portions 11a- ₂ and 11b- ₂ .

In order to mount the primary coil bobbin 2 and the secondary coil bobbin 3 on the case 4, first, as described above, the primary coil bobbin 2 is inserted into the insertion hole 7 of the secondary coil bobbin 3.
After being mounted in the case, it is mounted in the bottomed case 4 as shown in FIG. At this time, the width of the secondary coil bobbin 3 including the terminals 8a and 8b (indicated by the arrow L1 in the figure)
Is set to be larger than the inner width of the case 4 (indicated by an arrow L2 in the figure) (L1 <L2). Therefore, by mounting the secondary coil bobbin 3 in the case 4, the terminals 8a and 8b are urged by the inner wall of the case 4 and elastically deform.

FIG. 1 is a view showing a state in which the terminals 8a and 8b are elastically deformed by mounting the secondary coil bobbin 3 in the case 4. As shown in FIG.

In FIG. 2, terminals 8a and 8b indicated by alternate long and short dash lines show a state before the secondary coil bobbin 3 is mounted in the case 4. In this state, the terminals 8a and 8b are not elastically deformed, and the end lines 5a and 5b are in a state without slack.

However, since the width L1 of the secondary coil bobbin 3 including the terminals 8a and 8b is larger than the inner width L2 of the case 4 as described above, the secondary coil bobbin 3 is mounted in the case 4. By doing Terminal 8
A and 8b are relatively urged by the inner wall of the case 4 and elastically deform. The terminals 8a and 8b indicated by solid lines in FIG. 1 are in an elastically deformed state.

As shown in FIG.
8b is configured to be deformed inward (in the direction indicated by arrow B in the figure) by being urged by the inner wall of the case 4, so that the end line connected to the terminals 8a and 8b by this deformation. 5a and 5b are loosened (in each figure, the loosened portions are indicated by broken lines and reference numerals 12a and 12b).
b)). Therefore, even if the secondary coil bobbin 3 thermally expands, disconnection at the end lines 5a and 5b can be reliably prevented.

Further, as is apparent from FIG. 1, the amount of elastic deformation of the terminals 8a and 8b due to the mounting of the secondary coil bobbin 3 in the case 4 is such that the conventional terminal 41 is bent at a substantially right angle. Since the amount of deformation is smaller than that of FIG. 4 (see FIG. 4), it is possible to prevent the end wires 5a, 5b from being accidentally detached from the terminals 8a, 8b during this bending work, and to improve the reliability of the ignition coil device 1. Can be.

FIG. 3 is an enlarged view of the vicinity of the terminal 8a when the secondary coil bobbin 3 is mounted in the case 4. As shown in the figure, the terminal 8a elastically deformed in the mounted state is the external connection terminal 1 for high voltage.
The inner end 11a-1a is pressed with elastic restoring force . Therefore, the electrical connection between the terminal 8a and the high-voltage external connection terminal 11a can be reliably performed. still,
FIG. 3 shows the vicinity of the terminal 8a in an enlarged manner.
The other terminal 8b and the high-voltage external connection terminal 11b have the same structure , so that the electrical connection between the terminal 8b and the high-voltage external connection terminal 11b can be reliably performed.

Also, as described above, the terminals 8a and 8b
Is a high-voltage external connection terminal 1 fixed to the case 4 when the bobbin 3 for the secondary coil is mounted in the case 4.
1a and 11b are pressed, and this pressing force functions as a holding force for holding the secondary coil bobbin 3 in the case 4, so that the secondary coil bobbin 3 can be prevented from falling off the case 4. At the same time, it is possible to prevent rattling in the case 4 of the bobbin 3 for the secondary coil. In this embodiment, the terminals 8a, 8b
The rubber stoppers 13a,
13b, the secondary coil bobbin 3 can be held in the case 4 more reliably.

Further, as described above, the ignition coil device 1 according to the present embodiment does not require the conventional bending process for the terminal, so that the assembly process can be simplified and the terminal can be bent. It is possible to prevent the process from being forgotten, that is, skipping the process, and improve the reliability of the ignition coil device 1.

[0034]

As described above, according to the present invention, by attaching the bobbin to the case, the terminal is urged by the case and deformed, so that the end line connected to the terminal can be slackened. In addition, since the amount of elastic deformation of the terminal is set to a value that can maintain the elastic restoring force,
Since the amount of deformation is smaller than the conventional amount of bending at a substantially right angle, it is possible to reliably prevent the end line from coming off from the terminal at the time of deformation, and further, with the bobbin attached to the case, elasticity due to the elastic deformation
Since the case is pressed by the restoring force , this pressing force functions as a holding force for holding the bobbin to the case, and has features such as preventing the bobbin from dropping out of the case and rattling of the bobbin in the case. .

[Brief description of the drawings]

FIG. 1 is a plan view of an ignition coil device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of an ignition coil device according to one embodiment of the present invention.

FIG. 3 is an enlarged view showing the vicinity of a terminal in a state where a bobbin for a secondary coil is mounted in a case.

FIG. 4 is a diagram showing a conventional configuration for connecting an end of a coil wire to a terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ignition coil device 2 Primary coil fusion bobbin 3 Secondary coil fusion bobbin 4 Case 5 Coil wire 5a, 5b End line 6 Fin 7 Insertion hole 8a, 8b Terminal 9a, 9b High voltage external connection part 11a, 11b High voltage external connection terminal 13a, 13b Stopper

Claims (1)

(57) [Claims] 1. A body on which an internal combustion engine ignition coil is wound.
The end of the coil is connected to the bin and the bobbin.
And a case to which the bobbin is attached
An ignition coil device for an internal combustion engine constituted byThe terminal is formed of an elastically deformable member,
Connect the bobbin end line to the terminal with tension.
Including the terminal of the bobbin while entangled and fixed
Make the dimensions longer than the corresponding case dimensions,  When the bobbin is attached to the case, the terminal
The case is biased by the case and elastically deformed to
An internal combustion engine characterized in that a slack is formed in a wire.
Seki ignition coil device.