JPH08232825A - Ignition device integral with combustion pressure sensor - Google Patents

Abstract

PURPOSE: To reduce voltage reduction by providing an ignition coil having a connecting member on the opening port part of a plug installing hole formed on a cylinder head through a circuit maintaining part, and shortening the transmission distance of high voltage, and also to detect combustion pressure with high accuracy by connecting a combustion pressure sensor and a signal treatment circuit to each other through a signal line directly. CONSTITUTION: An ignition coil 7 is arranged on the opening port part 3D of a plug installing hole 3 through a circuit maintaining part 21, and connected to an ignition plug 6 by a connecting member 16. A combustion pressure sensor 18 is connected to a signal treatment circuit 22 through a signal line 23, and a core member 8 is fixed on a support projection 4 by a bolt B. The ignition coil 7 is thus fixed on a cylinder head 1. As a result, the connecting member 16 is shortened so as to improve ignitability of the ignition plug 6, superposition of noise is eliminated in the combustion pressure sensor 18 so as to improve detecting accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition device of the type in which an ignition coil is provided for each cylinder of an internal combustion engine,
In particular, the invention relates to a combustion pressure sensor integrated ignition device including a combustion pressure sensor.

[0002]

2. Description of the Related Art Generally, in an ignition device for causing a spark discharge in an ignition plug mounted on a cylinder head of an internal combustion engine, a voltage of 12 V from a battery is increased to a high voltage by using an ignition coil. There is a distributor system in which the power distribution unit of the distributor supplies the spark plug for each cylinder.

However, the distributor-type ignition device requires a long high-voltage cable because a high voltage generated from the ignition coil is supplied by the distributor to the ignition plugs mounted in each mechanism by controlling the ignition timing. However, there is a problem that the high voltage is lowered due to the voltage drop due to this cable, and noise is generated due to the influence of the electromagnetic wave generated from the high voltage cable.
Further, since the distributor has a power distribution unit that distributes power to each spark plug, there is a problem that the power distribution unit is worn or electric noise is generated from the power distribution unit.

As described above, in order to solve the problems of the ignition device using the distributor, the ignition device without the distributor, so-called DLI (Distributorless).
Ignition) is known. Further, in this ignition device, an ignition coil that generates a high voltage is provided for each cylinder of the cylinder head. The ignition coil is generally called a direct ignition coil, and the direct ignition coil includes a core, a primary coil wound around the outer periphery of the core, and a primary coil wound around the outer periphery of the core. It is mainly composed of a primary coil and a secondary coil wound concentrically. Further, except that the control unit is used in place of the distributor, the principle of generating the high voltage is the same as that of the distributor type ignition coil, but since the ignition coil is provided in the cylinder head, the high tension generated by the conventional ignition device is used. The cable can be eliminated and the power distribution unit can be configured by electrical switching (contactless switch).

On the other hand, as a combustion pressure sensor for detecting the combustion pressure of an internal combustion engine, for example, the one described in Japanese Utility Model Laid-Open No. 61-63134 is known. This combustion pressure sensor is a washer type including an annular piezoelectric body mounted in a state in which a preload is applied to a cylinder head, and an electrode plate provided on the piezoelectric body and deriving a detection voltage from the piezoelectric body. Pressure sensors are known. This combustion pressure sensor receives the pressure due to the vibration of the cylinder head generated by the combustion pressure of the internal combustion engine by the piezoelectric body, detects the detection signal as a voltage at the electrode plate according to this pressure, and outputs it to the external control unit. It is designed to output.

[0006]

By the way, in the combustion pressure sensor according to the prior art, a voltage corresponding to the combustion pressure is detected from the piezoelectric body, and this detection signal is transmitted by a transmission cable (harness).
To the control unit provided in the driver's cab of the vehicle, and the signal processing circuit provided in the control unit removes noise and performs waveform shaping, etc., and inputs it to the control circuit at the next stage. It was

However, such a combustion pressure sensor according to the conventional technique has a problem that the output impedance is high and noise is likely to be superposed because the piezoelectric type piezoelectric body is used as the piezoelectric body. In order to solve this, it is possible to connect a low noise cable (Low Noise Cable) with noise countermeasures to the control unit in order to extract the detection voltage from each electrode plate, but in this case the cost is high. At the same time, there is a problem that the detection accuracy of the combustion pressure decreases due to the temperature characteristics of the low noise cable.

Therefore, after performing signal processing so that the detection voltage from the combustion pressure sensor can be transmitted, a signal processing including a filter circuit and a preamplifier circuit for outputting to the control unit via the harness is performed. It is conceivable that a circuit is provided in the vicinity of the combustion pressure sensor, the signal processing circuit removes the influence of noise in advance, and the impedance is reduced to reduce the influence of noise on the output after amplification.

Therefore, in the above-mentioned direct ignition coil, it is considered to provide the coil and the combustion pressure sensor together on the cylinder head side and also provide the signal processing circuit on the cylinder head side.

The present invention has been made in view of the above-mentioned problems of the prior art. When the present invention is combined with an ignition device such as an ignition coil and a combustion pressure sensor for detecting combustion pressure, the detection signal from the combustion pressure sensor is used. An object of the present invention is to provide a combustion pressure sensor integrated ignition device that also includes a signal processing circuit that performs signal processing.

[0011]

In order to solve the above-mentioned problems, the combustion pressure sensor integrated ignition device adopted by the invention of claim 1 is mounted in a plug mounting hole opened in a combustion chamber of an internal combustion engine. A spark plug, an ignition coil provided on the outer opening side of the plug mounting hole for supplying a high voltage to the spark plug, and a plug in the plug mounting hole for connecting the ignition coil and the spark plug. A combustion pressure sensor that is provided between the plug mounting hole and the spark plug and that detects the combustion pressure in the combustion chamber, and that is provided near the opening of the plug mounting hole. A circuit holding unit, a signal processing circuit provided in the circuit holding unit, which processes a detection signal from the combustion pressure sensor and then outputs the signal as an output signal to the outside, and the combustion pressure sensor. Electrically it lies in the structure of the signal line connecting between the No. processing circuit.

According to a second aspect of the present invention, a sensor holding portion is provided in the plug mounting hole, and the combustion pressure sensor and the circuit holding portion are integrated by the sensor holding portion.

According to a third aspect of the present invention, the connection member and the ignition coil are integrally formed.

According to a fourth aspect of the present invention, the circuit holder and the ignition coil are integrally formed.

According to a fifth aspect of the present invention, the ignition coil comprises a core member and a high voltage generating coil wound around the core member, and the core member is a mounting means for mounting the ignition coil to an internal combustion engine. Especially.

[0016]

According to the first aspect of the present invention, since the ignition plug is attached to the plug mounting hole and the ignition coil is provided at the opening of the plug mounting hole, the length of the connecting member for connecting the ignition coil and the ignition coil is increased. The length can be shortened, and the voltage drop of the voltage supplied from the ignition coil to the spark plug can be reduced. Further, by electrically connecting the combustion pressure sensor and the signal processing circuit via the signal line on the internal combustion engine side, a connecting member such as a connector can be eliminated between the combustion pressure sensor and the signal processing circuit, and the combustion pressure can be eliminated. It is possible to prevent noise from being superimposed on the detection signal from the sensor.

According to the second aspect of the present invention, since the combustion pressure sensor and the circuit holding portion are integrated via the sensor holding portion, the combustion pressure sensor and the circuit holding portion are made into one member by the sensor holding portion, and combustion is performed. The detection signal from the pressure sensor can be directly transmitted to the signal processing circuit via the signal line attached to the sensor holding unit.

According to the third aspect of the present invention, by integrally forming the connecting member and the ignition coil, the distance between the output side of the ignition coil and the input side of the ignition plug can be shortened, and the voltage supplied from the ignition coil to the ignition plug can be shortened. The voltage drop can be reduced and the number of parts can be reduced.

According to the fourth aspect of the invention, by integrally forming the circuit holding portion and the ignition coil, both can be handled as one component, and the number of components can be reduced.

According to the fifth aspect of the present invention, the ignition coil can be fixed to the internal combustion engine by using the core member by fixing the ignition coil to the internal combustion engine using the core member as a mounting means.

[0021]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 8, and FIGS. 1 to 5 show a first embodiment of the present invention.

In the figure, reference numeral 1 denotes a cylinder head of an internal combustion engine, and a combustion chamber 2 is formed for each of a plurality of cylinders (only one is shown) in the cylinder head 1.

Reference numeral 3 is a plug mounting hole provided in the cylinder head 1, and the plug mounting hole 3 is a combustion chamber 2 of the cylinder head 1.
A large-diameter plug insertion hole 3A that extends toward the bottom and a small-diameter screw hole 3C that is located at the hole bottom 3B of the insertion hole 3A and that opens into the combustion chamber 2 are formed. The opening 3D is formed, and one positioning hole 3E is formed in the vicinity of the opening 3D as shown in FIG. 2, and the positioning protrusion 2 formed in the circuit holding portion 21 described later in the positioning hole 3E.
The circuit holding portion 21 is positioned by engaging 1D.

4, 4 and 4 are openings 3D of the plug mounting holes 3
Orthogonal 3 located in the vicinity and different from the positioning hole 3E
The support protrusions are formed so as to project upward at certain positions. Each of the support protrusions 4 is formed in a prismatic shape, and a bolting hole 4A is formed in the center thereof. Each screw insertion of a core member 8 described later is performed. 3 bolts B through hole 8A (only 1 shown)
By screwing into the bolt hole 4A with
The core member 8 is attached to the support protrusion 4 and fixed to the cylinder head 1.

Reference numeral 5 denotes an ignition device integrated with a combustion pressure sensor according to the present embodiment which is attached to the cylinder head 1. The ignition device 5 is an ignition plug 6 which will be described later and is screwed into a screw hole 3C of a plug mounting hole 3. And an ignition coil 7 located at the opening 3D of the plug mounting hole 3 and provided via the circuit holding portion 21, and the ignition coil 7 and the ignition coil 7 in order to connect the ignition coil 7 and the ignition plug 6 together. The connecting member 16 formed, the combustion pressure sensor 18 provided between the hole bottom 3B of the plug mounting hole 3 and the ignition plug 6 for detecting the combustion pressure in the combustion chamber 2, and the plug mounting hole 3 Circuit holder 2 provided at the opening 3D
1 and the combustion pressure sensor 18 provided in the circuit holding portion 21.
Signal processing circuit 22 for processing the detection signal from the engine, a signal line 23 for electrically connecting the combustion pressure sensor 18 and the circuit holding portion 21, and a sensor for fixing the combustion pressure sensor 18 to the circuit holding portion 21. The holding unit 25 and the holding unit 25 are included.

Reference numeral 6 denotes an ignition plug which is screwed and attached to the screw hole 3C of the plug attachment hole 3, and the ignition plug 6 has an ignition electrode portion 6A, a screw portion 6B, a housing 6C, a nut portion 6D, in this order from the tip end side. Insulator part 6E and input terminal part 6F
Consists of

Reference numeral 7 is an ignition coil fixedly attached to the cylinder head 1 by a bolt B via the circuit holding portion 21. The ignition coil 7 is wound around the core member 8 and the outer periphery of one side of the core member 8. And a high voltage generating coil 9.

Here, as shown in FIG. 3, the core member 8 is formed in an annular shape having a quadrangular outer shape, and is positioned at a predetermined position of the core member 8 by collating with each supporting protrusion 4 of the cylinder head 1. There are three screw insertion holes 8A for carrying out. The ignition coil 7 is connected to the circuit holder 2
1, the screw insertion holes 8A of the core member 8 are aligned with the bolt fixing holes 4A of the support protrusions 4, and the bolts B are screwed into the bolt fixing holes 4A through the screw insertion holes 8A, whereby the ignition coil 7 can be fixed to the opening 3D side of the plug mounting hole 3 via the circuit holding portion 21.

Further, the high voltage generating coil 9 is located on one side of the core member 8 and is coaxially formed on the outer periphery of the core member 8 with a primary coil bobbin 10A and a secondary coil bobbin 10B.
A coil bobbin 10 composed of a primary coil 11, a primary coil 11 located on the outer circumference of the core member 8 and concentrically wound around a primary coil bobbin 10A, and a secondary coil bobbin 10B located on the outer circumference of the primary coil 11. And a secondary coil 12 wound in a concentric manner with the interposition of.

Reference numeral 13 is a coil bobbin 10 and a primary coil 11
And the secondary coil 12 to cover the ignition coil 7
The casing is formed of a resin material in the shape of a rectangular parallelepiped, and an input terminal 14 connected to the inside primary coil 11 is formed on the upper side of the casing 13 so as to project.

Reference numeral 15 represents a harness, which is composed of a male connector 15A and a lead wire 15B, and a control unit (not shown) provided in the vehicle compartment is connected to the lead wire 15B. And the harness 1
By connecting the male connector 15A of No. 5 to the input terminal 14 and the female connector 24 described later, the control unit and the signal processing circuit 22, the signal processing circuit 22 and the ignition coil 7, and the control unit and the ignition coil 7 are connected respectively. It has become.

Next, 16 is a connecting member which is integrally formed with the ignition coil 7 and which is disposed in the plug insertion hole 3A from the ignition coil 7. The tip of the connecting member 16 is the input terminal portion 6F of the ignition plug 6. It is a plug holding portion 17 connected to. Here, the plug holding portion 1
Reference numeral 7 denotes an insulator holding portion 17A which is located on the tip end side and holds the insulator portion 6E of the spark plug 6, a springy conductor 17B which is located in the insulator holding portion 17A and extends in the axial direction, and the springy conductor 17B. A connecting terminal 17C that is fixed to the tip of the spark plug 6 and contacts the input terminal portion 6F of the spark plug 6. Then, the connecting member 16 supplies the high voltage output from the ignition coil 7 to the spark plug 6.

Reference numeral 18 denotes a combustion pressure sensor according to this embodiment. The combustion pressure sensor 18 is located at the mounting portion 25A of the sensor holding portion 25 as shown in FIG. 4 and between the ignition plug 6 and the hole bottom 3B. And a pair of annular electrode plates 20 provided on both sides of the piezoelectric body 19 in the axial direction of the piezoelectric body 19, which are provided via a washer 25B and are preloaded by the tightening force of the ignition plug 6. , 20 and.

In the combustion pressure sensor 18, when the internal combustion engine is started and combustion pressure is generated in the combustion chamber 2, the spark plug 6 receives the combustion pressure and changes the preload applied to the piezoelectric body 19, Each annular electrode plate 20 outputs this change in preload as a detection signal corresponding to the combustion pressure.

Reference numeral 21 denotes a circuit holding portion fixedly provided on the opening 3D side of the plug mounting hole 3, and the circuit holding portion 21 is
As shown in FIG. 5, an annular portion 21A having a square outer shape and an inner peripheral surface that is a through hole 21A1 so as to cover the opening 3D of the plug mounting hole 3, and an axial direction from one outer peripheral surface of the annular portion 21A. The signal processing circuit 22 is embedded in the circuit accommodating portion 21B by a resin mold 21C, and the lower surface of the annular portion 21A has a positioning hole 3E for the cylinder head 1. A positioning protrusion 21D that engages with is formed to project.

Reference numeral 22 denotes a signal processing circuit provided in the circuit holding section 21. The signal processing circuit 22 is composed of a board 22A and electronic parts 22B which are mounted on the board 22A and constitute a filter circuit, a preamplifier circuit and the like. The signal processing circuit 22 is connected to the combustion pressure sensor 18 via the signal line 23. In addition, a power transistor used for ignition control is mounted in the electronic component 22B, and when an ignition signal is input from the control unit, this power transistor performs a switching operation and the connectors 15A, 24
An ignition signal is input to the ignition coil 7 via.

Reference numeral 23 denotes a signal line arranged along the sensor holding portion 25. The signal line 23 is located in the circuit holding portion 21 and the exposure signal line 23A extending in the plug insertion hole 3A. A buried signal line 23B connected to the signal processing circuit 22
The signal line 23 electrically connects the combustion pressure sensor 18 and the signal processing circuit 22.

Reference numeral 24 denotes a circuit accommodating portion 21B of the circuit holding portion 21.
Shows the female connector formed in FIG. 1, and by connecting the female connector 24 to the male connector 15A, an output signal corresponding to the combustion pressure from the signal processing circuit 22 is led to the control unit via the harness 15. ing.

Reference numeral 25 denotes the combustion pressure sensor 18 and the circuit holding portion 21.
2 shows a sensor holding portion disposed in the plug mounting hole 3 for fixing to the sensor holding portion 25. The sensor holding portion 25 is formed of a resin material or a metal material in a cylindrical shape, and the base end side of the sensor holding portion 25 is a circuit. The mounting portion 25A is embedded in the holding portion 21 and has a tip end side that is bent inward in the radial direction. Further, the exposed signal line 23 of the signal line 23 is provided on the outer peripheral surface of the sensor holding portion 25.
A is attached.

Next, the mounting operation for mounting the ignition device 5 on the cylinder head 1 will be described.

First, the plug mounting hole 3 of the cylinder head 1
The circuit holding portion 21 is attached to the opening portion 3D. At this time, the sensor holding portion 25 is inserted into the plug insertion hole 3A, the combustion pressure sensor 18 is brought into contact with the hole bottom 3B, and the positioning protrusion 21D of the circuit holding portion 21 is engaged with the positioning hole 3E of the cylinder head 1. Let

Next, with the circuit holder 21 positioned in the opening 3D, the circuit holder 21 is inserted into the insertion hole 21A1 of the annular portion 21A of the circuit holder 21 and the ignition plug 6 is fixed to a jig (for example, a plug wrench or a driver). Etc.) into the plug mounting hole 3 and screw the screw portion 6B of the ignition plug 6 into the screw hole 3C. At this time, the attachment portion 25A of the sensor holding portion 25 and the combustion pressure sensor 18 are sandwiched between the housing 6C and the hole bottom 3B.

As a result, the combustion pressure sensor 18 is mounted in the plug mounting hole 3 together with the spark plug 6. In addition, the combustion pressure sensor 18 and the circuit holding unit 2 are provided by the sensor holding unit 25.
1 and the cylinder head 1 are integrally formed.
The circuit holder 21 can also be fixed.

Further, in order to attach the ignition coil 7 having the connecting member 16 to the ignition plug 6, the plug holding portion 17 of the connecting member 16 is inserted into the insertion hole 21 of the circuit holding portion 21.
Insert into the insulator portion 6E of the spark plug 6 via A1. At this time, the screw insertion holes 8A formed in the core member 8 of the ignition coil 7 are aligned with the support protrusions 4 formed in the cylinder head 1. After this, the core member 8
The ignition coil 7 can be fixed to the cylinder head 1 via the circuit holding portion 21 by fixing the screw insertion hole 8A and the bolt fixing hole 4A of each support protrusion 4 with the bolt B.

Finally, by connecting the male connector 15A of the harness 15 to the input terminal 14 of the ignition coil 7 and the female connector 24 of the circuit holder 21, the combustion pressure integrated ignition device 5 is connected to the control unit. can do.

The combustion pressure sensor integrated type ignition device 5 according to the present embodiment is constructed as described above. Next, the operation of the ignition device will be described.

First, the ignition signal output from the control unit is passed through the harness 15 to the signal processing circuit 22.
Is input to the power transistor, and based on this ignition signal, a control signal is applied from the power transistor to the primary coil 11 as a low voltage DC current via the male connector 15A. Furthermore, the current applied to the primary coil 11 is suddenly cut off by the power transistor, so that an electromagnetic induction action occurs, and a high voltage is generated in the secondary coil 12 via the core member 8. Then, this high voltage is supplied to the ignition plug 6 through a connecting member 16 integrally formed with the ignition coil 7, and in the ignition plug 6, a spark discharge is generated at the ignition electrode portion 6A, and the air-fuel mixture in the combustion chamber 2 is discharged. The internal combustion engine can be operated by ignition and explosion.

However, in the present embodiment, by integrally forming the ignition coil 7 and the connecting member 16, the distance through which the high voltage flows between the ignition coil 7 and the ignition plug 6 can be made extremely short, and the high voltage can be reduced. The voltage drop is reduced and the plug miss (ignition failure) due to the spark plug 6 is prevented. As a result, the ignitability of the air-fuel mixture in each combustion chamber 2 can be significantly enhanced, and the operating performance of the internal combustion engine can be improved.

Further, since the ignition coil 7 is integrated with the connecting member 16, the mounting to the plug mounting hole 3 is also carried out through the circuit holding portion 21, and the core member 8 is bolted to the support projection 4. The ignition coil 7 can be easily fixed to the cylinder head 1. At this time, the plug holding portion 17 of the connecting member 16 can be attached to the input terminal portion 6F of the ignition plug 6, and the ignition plug 6 and the ignition coil 7 can be connected.

Next, the operation of detecting the combustion pressure will be described.

First, when the internal combustion engine is started and combustion pressure is generated in the combustion chamber 2, this combustion pressure is received via the spark plug 6, and the preload applied to the piezoelectric body 19 of the combustion pressure sensor 18 changes. This change is detected as a detection signal corresponding to the combustion pressure, and this detection signal is sent to the signal processing circuit 22 through the signal line 23.
Is output via. In the signal processing circuit 22, the detection signal is subjected to signal processing by a filter circuit, a preamplifier circuit, etc., and is output as a high voltage value to the connector 15A
It outputs to the control unit via 24 and the harness 15.

Therefore, in this embodiment, the cylinder head 1
On the side, the combustion pressure sensor 18 and the signal processing circuit 22 are integrally formed via the sensor holding portion 25, and both are directly connected by the signal line 23. Therefore, between the combustion pressure sensor 18 and the signal processing circuit 22. Since it is not necessary to provide a connecting member such as a connector in, the contact resistance can be eliminated. This allows
The S / N ratio of the detection signal output from the combustion pressure sensor 18 to the signal processing circuit 22 can be increased.

Further, since the signal line 23 can directly connect the combustion pressure sensor 18 and the signal processing circuit 22 at a position of the cylinder head 1, the detection signal from the combustion pressure sensor 18 reaches the signal processing circuit 22. It is possible to prevent the noise from being superimposed until the above, and to improve the detection accuracy of the combustion pressure.

Moreover, since the voltage value of the output signal is increased by the signal processing circuit 22, the connectors 15A, 2
4 and the output signal output to the control unit via the harness 15, even if noise is superimposed on the S /
Since the N ratio is high, the combustion pressure can be accurately detected. As a result, it is possible to accurately control the fuel injection amount, the ignition timing, etc., and improve the operation of the internal combustion engine.

Next, FIG. 6 to FIG. 8 show a second embodiment. The feature of this embodiment is that the circuit holding portion for holding the signal processing circuit is formed integrally with the ignition coil and the core member is formed. The high voltage generating coil to be wound is disposed on three sides of the four sides of the core member. The same components as those in the first embodiment described above are designated by the same reference numerals,
The description will be omitted.

In the figure, reference numeral 31 denotes a cylinder head of an internal combustion machine, and a combustion chamber 32 is formed for each of a plurality (only one is shown) of the cylinder head 31.

Reference numeral 33 denotes a plug mounting hole provided in the cylinder head 31, and the plug mounting hole 33 has a large diameter plug insertion hole 33A extending toward the combustion chamber 32 of the cylinder head 31.
And a small-diameter screw hole 33C that is located at the hole bottom 33B of the insertion hole 33A and opens into the combustion chamber 32, and the outside of the plug mounting hole 33 becomes an opening 33D.
In the vicinity of 3D, as shown in FIG. 7, positioning holes 33E, 3
Two 3E are formed in the radial direction, and positioning of the ignition coil 36 is performed by engaging a positioning protrusion 39A formed on an ignition coil 36, which will be described later, with each of the positioning holes 33E.

Reference numerals 34, 34, ... Denote support projections formed to project upward at four positions orthogonal to each other in the vicinity of the opening 33D of the plug mounting hole 33. Each of the support projections 34 has a bolt at the center thereof. Formed into a prismatic shape having a stop hole 34A,
The core member 37 is fixed to the support projection 34 and fixed to the cylinder head 31 by being screwed to the bolting hole 34A with a bolt (not shown) through each screw insertion hole 37B of the core member 37 described later.

Reference numeral 35 indicates an ignition device integrated with a combustion pressure sensor of this embodiment which is attached to the cylinder head 31, and the ignition device 35 includes an ignition plug 6 screwed into a screw hole 33C of a plug attachment hole 33, and a plug. Opening 33D of mounting hole 33
Is provided between the ignition coil 36 provided at the position, the connection member 41 connecting the ignition coil 36 and the ignition plug 6, and the hole bottom 33B of the plug mounting hole 33 and the ignition plug 6. A combustion pressure sensor 44 that detects the combustion pressure in the chamber 32, a circuit holding portion 45 that is provided integrally with the ignition coil 36, and a detection signal from the combustion pressure sensor 44 that is provided in the circuit holding portion 45. A signal processing circuit 46 for processing, and a signal line 4 for electrically connecting the combustion pressure sensor 44 and the circuit holder 45.
7 and the combustion pressure sensor 44 to the ignition coil 3
Sensor holding part 48 fixed to the circuit holding part 45 via 6
It is composed of and.

Reference numeral 36 denotes an ignition coil fixed to the opening 33D of the plug mounting hole 33 by a bolt and having an insertion hole 36A.
6 is integrally formed with a circuit holding portion 45 described later, and the ignition coil 36 includes a core member 37 and a core member 37.
The high voltage generating coil 38 is wound around the outer circumference of three of the four sides.

Here, as shown in FIG. 8, the core member 37 is formed in an annular shape having a rectangular outer shape.
Four support portions 37A extending in the radial direction are formed from the respective apexes of the screw insertion holes 37 in the central portions of the respective support portions 37A.
B is formed respectively.

Further, the high voltage generating coil 38 is located on three sides of the core member 37 and wound around the primary coil 38.
A and secondary coils 38B and 38C.

Reference numeral 39 denotes a casing which is formed in a rectangular parallelepiped shape so as to cover the core member 37 and the high-voltage generating coil 38 with an insulating resin material so that the inner peripheral surface serves as an insertion hole.
On the lower surface of the casing 39, positioning protrusions 39A, 39A that engage with the positioning holes 33E, 33E formed in the cylinder head 31 are formed to project, and the high voltage generating coil 38 among the four sides of the core member 37 is formed. A circuit holding portion 45 is formed on one side where is not wound.

Reference numeral 40 denotes a female connector formed on the side surface of the ignition coil 36. The connector 40 connects the signal processing circuit 46 and an external control unit via a harness (neither is shown), On the upper side of the connector 40, a high voltage terminal 40A for outputting a high voltage boosted by the ignition coil 36 is formed.

Reference numeral 41 denotes a connecting member for connecting the ignition coil 36 and the ignition plug 6, and the connecting member 41
Is connected to the high-voltage terminal 40A and a plug holding portion 41A having a large-diameter cylindrical body that is inserted into the plug mounting hole 33 and having an insulator holding portion 41B that holds the insulator portion 6E of the ignition plug 6 at its tip. It is composed of a small diameter coil connecting portion 41C and a connecting portion 41D connecting the coil connecting portion 41C and the plug holding portion 41A.

Reference numeral 42 is a coil connecting portion 41C of the connecting member 41.
And a core wire embedded in a part of the connecting member 41 and the plug holding portion 41A, and the tip of the core wire 42 has a high voltage generating coil 3
8 high-voltage terminals 40A. Reference numeral 43 denotes a spring-like conductor provided in the plug holding portion 41A, the base end of the spring-like conductor 43 is connected to the core wire 42, and the tip end thereof is provided with a connection terminal 43A that abuts the input terminal portion 6F of the ignition plug 6. Has been. Then, the connecting member 41 supplies the high voltage output from the ignition coil 36 to the spark plug 6.

Reference numeral 44 denotes a combustion pressure sensor, which is constructed similarly to the combustion pressure sensor 18 according to the first embodiment and is located at the mounting portion 48A of the sensor holding portion 48,
In addition, a preload is maintained between the ignition plug 6 and the hole bottom 33B.

Reference numeral 45 denotes a circuit holding portion integrally formed with the ignition coil 36, and the circuit holding portion 45 is located above one side of the four sides of the core member 37 on which the high voltage generating coil 38 is not wound. However, the signal processing circuit 46 is held.

Reference numeral 46 denotes a signal processing circuit provided in the circuit holding section 45. The signal processing circuit 46 includes a board 46A and electronic parts 46B which are mounted on the board 46A and constitute a filter circuit, a preamplifier circuit and the like. The signal processing circuit 46 is connected to the combustion pressure sensor 44 via a signal line 47. In addition, a power transistor used for ignition control is mounted in the electronic component 46B, and when an ignition signal is input from the control unit, this power transistor performs a switch operation to input the ignition signal to the ignition coil 36. It has become.

Reference numeral 47 denotes a signal line arranged along the sensor holding portion 48. The signal line 47 is located in the ignition coil 36 and the exposure signal line 47A extending in the plug insertion hole 3A. The signal line 47 includes a buried signal line 47B connected to the processing circuit 46.
4 and the signal processing circuit 46 are connected.

Reference numeral 48 denotes a sensor holding portion arranged in the plug mounting hole 33 for fixing the combustion pressure sensor 44 to the ignition coil 36, and the sensor holding portion 48 is formed of a resin material or a metal material in a cylindrical shape. Has been done. Further, the base end side of the sensor holding portion 48 is embedded in the ignition coil 36, and the tip end side is a mounting portion 48A bent inward in the radial direction. In addition, the sensor holding portion 48 connects the combustion pressure sensor 44 and the circuit holding portion 45 via the ignition coil 36. Further, the sensor holding portion 48 is additionally provided with an exposure signal line 47A of the signal line 47.

Next, the ignition device 35 is attached to the cylinder head 31.
The mounting operation for mounting on the will be described.

First, the ignition coil 36 is attached to the opening 33D of the plug mounting hole 33 of the cylinder head 31. At this time, the sensor holding portion 48 is connected to the plug insertion hole 33A.
The combustion pressure sensor 44 is brought into contact with the hole bottom 33B, and the positioning protrusions 39 of the ignition coil 36 are inserted.
A is engaged with each positioning hole 33E of the cylinder head 31. As a result, each screw insertion hole 37B of the core member 37
Correspond to each support protrusion 34. Then, the core member 37 is fixed to the support protrusion 34 and the ignition coil 36 is fixed to the cylinder head 31 by screwing the bolt into the bolt fastening hole 34A through the screw insertion hole 37B.

Next, in this state, the ignition plug 6 is inserted into the ignition coil 36 by using a jig (plug wrench) into the plug mounting hole 33 through the insertion hole 36A of the ignition coil 36, and the screw hole 33C is formed. The threaded portion 6B of the spark plug 6 is screwed into. At this time, the housing 6
The mounting portion 48 of the sensor holding portion 48 is provided between C and the hole bottom 33B.
The combustion pressure sensor 44 can be sandwiched between A and the combustion pressure sensor 44 to be preloaded.

As a result, the combustion pressure sensor 44 is attached to the plug attachment hole 33 together with the spark plug 6. Further, since the combustion pressure sensor 44 and the circuit holding portion 45 (ignition coil 36) are integrally formed by the sensor holding portion 48, the circuit holding portion 45 can also be fixed to the cylinder head 31.

Furthermore, in order to attach the connecting member 41 to the ignition coil 36 and the ignition plug 6, the connecting member 41
The plug holding part 41A is inserted into the ignition plug 6 through the insertion hole 36A of the ignition coil 36, and the insulator holding part 41B holds the insulator part 6E, so that the plug holding part 41A is attached to the ignition plug 6. . At this time, the coil connecting portion 41C is mounted so as to be connected to the high voltage terminal 40A of the ignition coil 36.

The combustion pressure sensor integrated type ignition device 35 according to the present embodiment is constructed as described above, and the operation and effect of the ignition device are similar to those of the first embodiment described above. By connecting the portion through which the high voltage flows up to the plug 6 with the short connecting member 41, the voltage drop in the connecting member 41 can be reduced and the ignitability of the ignition plug 6 can be improved. Further, in this embodiment, since the primary coil 38A and the secondary coils 38B and 38C of the high voltage generating coil 38 are arranged on the core member 37, the high voltage generating efficiency can be improved.

On the other hand, also in the detection of the combustion pressure, the combustion pressure sensor 44 and the ignition coil 36 (circuit holding unit 4
Since the signal processing circuit 46 provided in 5) is connected via the signal line 47, contact resistance due to a connecting member such as a connector is eliminated, the S / N ratio of the detection signal is increased, and the combustion pressure is detected with high accuracy. be able to.

In each of the above embodiments, the combustion pressure sensor 1
However, the present invention is not limited to this, and may have a shape in which two or three layers are laminated and an electrode plate is disposed between each layer.

Further, the sensor holder 2 according to each of the above embodiments
Although the shapes of the cylinders 5 and 48 are cylindrical, the present invention is not limited to this, and may be in the shape of a bar and a rod.
4 may be fixed to the circuit holder 21 and the ignition coil 36.

[0081]

As described above in detail, according to the present invention of claim 1, since the ignition plug is attached to the plug mounting hole and the ignition coil is provided at the opening of the plug mounting hole, the ignition coil is provided. The length of the connecting member that connects the ignition coil with the ignition coil can be shortened, the voltage drop of the voltage supplied from the ignition coil to the ignition plug can be reduced, and the ignition performance of the ignition plug can be significantly improved, improving the operating performance of the internal combustion engine. Can be made. Further, by electrically connecting the combustion pressure sensor and the signal processing circuit via the signal line on the internal combustion engine side, a connecting member such as a connector can be eliminated between the combustion pressure sensor and the signal processing circuit, and the combustion pressure can be eliminated. It is possible to prevent noise from being superposed on the detection signal from the sensor, detect the combustion pressure with high accuracy, and accurately control the fuel injection amount, ignition timing, and the like.

According to the second aspect of the present invention, since the combustion pressure sensor and the circuit holding portion are integrated via the sensor holding portion, the combustion pressure sensor and the circuit holding portion are integrated into one member by the sensor holding portion, and the combustion is performed. The detection signal from the pressure sensor can be directly transmitted to the signal processing circuit via the signal line attached to the sensor holding portion, noise can be prevented from being superimposed on the detection signal, and detection accuracy can be improved. .

According to the third aspect of the present invention, by integrally forming the connecting member and the ignition coil, the distance between the output side of the ignition coil and the input side of the ignition plug can be made extremely short, and the ignition coil supplies the ignition plug. It is possible to reduce the voltage drop of the voltage, improve the ignition performance of the spark plug, and reduce the number of parts.

According to the fourth aspect of the present invention, by integrally forming the circuit holding portion and the ignition coil, both can be handled as one component, and the number of components can be reduced.

According to the fifth aspect of the present invention, the ignition coil can be fixed to the internal combustion engine by using the core member by fixing the ignition coil to the internal combustion engine using the core member as a mounting means.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state in which an ignition device according to a first embodiment is attached to a cylinder head.

FIG. 2 is a plan view of the cylinder head in FIG. 1 seen from above.

FIG. 3 is a plan view of the ignition coil in FIG. 1 seen from above.

FIG. 4 is an enlarged vertical sectional view showing an enlarged combustion pressure sensor in FIG.

FIG. 5 is a plan view of the circuit holding unit in FIG. 1 seen from above.

FIG. 6 is a vertical cross-sectional view showing a state in which an ignition device according to a second embodiment is attached to a cylinder head.

FIG. 7 is a plan view of the cylinder head in FIG. 6 viewed from above.

8 is a cross-sectional view as seen from the direction of arrows VIII-VIII in FIG.

[Explanation of symbols]

 1,31 Cylinder head 2,32 Combustion chamber 3,33 Plug mounting hole 5,35 Ignition device 6 Ignition plug 7,36 Ignition coil 8,37 Core member 9,38 High voltage generating coil 16,41 Connection member 18,44 Combustion Pressure sensor 21,45 Circuit holding unit 22,46 Signal processing circuit 23,47 Signal line 25,48 Sensor holding unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01L 23/22 G01L 23/22

Claims (5)

[Claims] 1. A spark plug mounted in a plug mounting hole that opens into a combustion chamber of an internal combustion engine, and a spark plug that is provided on the outer opening side of the plug mounting hole for supplying a high voltage to the spark plug. An ignition coil, a connecting member extending through the plug mounting hole for connecting the ignition coil and the ignition plug, and provided between the plug mounting hole and the ignition plug to detect the combustion pressure in the combustion chamber. A combustion pressure sensor, a circuit holding portion provided near the opening of the plug mounting hole, and a circuit holding portion which is provided in the circuit holding portion and which processes a detection signal from the combustion pressure sensor to the outside. A signal processing circuit for outputting as an output signal,
A combustion pressure sensor integrated ignition device comprising a signal line electrically connecting the combustion pressure sensor and a signal processing circuit. 2. A sensor holder is provided in the plug mounting hole, the combustion pressure sensor and the circuit holder are integrated by the sensor holder, and the signal line is attached to the sensor holder. The combustion pressure sensor integrated ignition device according to claim 1. 3. The combustion pressure sensor integrated ignition device according to claim 1, wherein the connection member and the ignition coil are integrally formed. 4. The combustion pressure sensor integrated ignition device according to claim 1, wherein the circuit holder and the ignition coil are integrally formed. 5. The ignition coil comprises a core member and a high voltage generating coil wound around the core member, and the core member serves as a mounting means for mounting the ignition coil to an internal combustion engine. , 3 or 4
A combustion pressure sensor integrated ignition device as described.