JP2016133067A - Fuel injection valve with in-cylinder pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a signal transmission member to be stored within a fuel injection valve with in-cylinder pressure sensor without increasing a size in its radial direction.SOLUTION: A bobbin 30 having a coil 28 installed therein is stored in a holder 32 of a housing 12 constituting a fuel injection valve 10 and a storing part 48 of which width is expanded in a radial outward direction against an inner peripheral surface of the holder 32 is formed in it. Since the second signal transmission member 70 for use in transmitting a detection signal outputted from a sensor 20 is stored in the storing part 48, it is avoided that a size of an outer diameter of the fuel injection valve 10 is increased even if a signal transmission part 24 including the second signal transmission member 70 is installed in it.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel injection valve with an in-cylinder pressure sensor that is used in a direct injection type internal combustion engine that directly injects into a combustion chamber of the internal combustion engine and has a sensor capable of detecting the in-cylinder pressure in the combustion chamber.

  2. Description of the Related Art Conventionally, an internal pressure sensor is known at the tip of a fuel injection valve for the purpose of detecting the in-cylinder pressure of a combustion chamber in an internal combustion engine. This internal pressure sensor is disposed between the tip of the fuel injection valve and the mounting hole of the cylinder head constituting the internal combustion engine. The internal pressure sensor has a lead wire for transmitting the detected in-cylinder pressure as an output signal to the outside. Is connected. The lead wire is connected to, for example, an electronic control unit, and the in-cylinder pressure is output to the electronic control unit as an output signal, whereby control based on the in-cylinder pressure is performed (see, for example, Patent Document 1). ).

JP-A-9-53483

  However, in the internal pressure sensor attached to the fuel injection valve described above, the lead wire connecting the internal pressure sensor and the electronic control unit is exposed to the outside of the fuel injection valve. Therefore, for example, when the internal pressure sensor is assembled to the cylinder head together with the fuel injection valve or in the assembled state, there is a risk of disconnection due to a load applied to the lead wire, and the in-cylinder pressure cannot be detected due to the disconnection. Concerned.

  Thus, for example, it is conceivable to store a lead wire for connecting the internal pressure sensor and the electronic control unit inside the fuel injection valve. However, the outer diameter of the fuel injection valve is increased by the amount that the lead wire is stored. There is a problem that it ends up.

  The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide a fuel injection valve with an in-cylinder pressure sensor that can accommodate a signal transmission member therein without increasing the size in the radial direction. .

In order to achieve the above-mentioned object, the present invention has a sensor that detects the in-cylinder pressure in a combustion chamber at the end of a fuel injection valve that directly injects fuel into the combustion chamber of an internal combustion engine, and includes a coil. In the fuel injection valve with an in-cylinder pressure sensor for driving the valve body under the energization action to the assembly,
The coil assembly is covered with a cylindrical housing constituting a magnetic path, and the housing is widened radially outward from the inner peripheral surface of the signal transmission member for transmitting the in-cylinder pressure detected by the sensor as a detection signal. It is characterized in that a storage section for storing is provided.

  According to the present invention, in the fuel injection valve with an in-cylinder pressure sensor having a sensor for detecting the in-cylinder pressure in the combustion chamber, the housing is provided with a storage portion that is widened radially outward with respect to the inner peripheral surface thereof. A signal transmission member that transmits the in-cylinder pressure detected by the sensor as a detection signal is stored in the storage unit.

  Therefore, since the signal transmission member can be suitably accommodated in the housing portion widened radially outward in the housing, the housing does not increase in size in the radial direction.

  As a result, the signal transmission member can be suitably housed inside the housing without enlarging the housing in the radial direction, and the detection signal from the sensor is output to the outside through the signal transmission member housed inside. It becomes possible. Moreover, although the housing functions as a magnetic circuit, since only a part of the housing is configured as a storage portion, the function of the magnetic circuit is reliably ensured and a reduction in attractive force is prevented.

  Further, the storage portion may be formed by partially expanding the inner peripheral surface of the housing.

  Further, the storage portion may be formed at a position on the signal terminal side where the detection signal from the signal transmission member is output in the housing.

  According to the present invention, the following effects can be obtained.

  That is, in a fuel injection valve with an in-cylinder pressure sensor having a sensor for detecting an in-cylinder pressure in a combustion chamber, a housing portion that is widened radially outward with respect to the inner peripheral surface is provided inside the housing. Since the signal transmission member that transmits the in-cylinder pressure detected by the sensor as a detection signal is housed in the housing, the signal transmission member can be suitably housed inside while preventing the housing from being enlarged in the radial direction. Become. Moreover, although the housing functions as a magnetic circuit, since only a part of the housing is configured as a storage portion, the function of the magnetic circuit is reliably ensured and a reduction in attractive force is prevented.

It is a partial cross section front view of the fuel injection valve with a cylinder pressure sensor which concerns on embodiment of this invention. It is an expanded sectional view which shows the bobbin and holder vicinity of the housing in the fuel injection valve with a cylinder pressure sensor of FIG. It is sectional drawing along the III-III line of FIG.

  The fuel injection valve with an in-cylinder pressure sensor according to the present invention will be described in detail below with reference to the accompanying drawings by giving preferred embodiments. In FIG. 1, reference numeral 10 indicates a fuel injection valve with an in-cylinder pressure sensor according to an embodiment of the present invention.

  As shown in FIG. 1, the fuel injection valve 10 with a cylinder pressure sensor (hereinafter simply referred to as a fuel injection valve 10) includes a housing 12, a resin mold portion 14 provided on the outer peripheral side of the housing 12, and the housing 12, a fuel supply unit 16 that is supplied with fuel, a fuel injection unit 18 that is provided at the front end of the housing 12, a sensor 20 that is attached to the front end of the fuel injection unit 18, and an electronic device (not shown). A signal transmission unit (signal transmission member) 24 for transmitting a detection signal by electrically connecting the signal terminal 22 connected to a control unit (ECU) and the sensor 20 is included.

  Hereinafter, as shown in FIG. 1, the fuel supply unit 16 side of the fuel injection valve 10 is described as a base end side (arrow A direction), and the fuel injection unit 18 side is described as a front end side (arrow B direction).

  The housing 12 is configured as a solenoid unit that drives the fuel injection valve 10, and includes a fixed core 26 provided at the center thereof, a bobbin 30 provided on the outer peripheral side of the fixed core 26 and holding a coil 28, Furthermore, it has a cylindrical holder (housing) 32 provided on the outer peripheral side of the tip, and a movable core (not shown) that is displaced under the exciting action of the coil 28.

  The fixed core 26 further extends toward the base end side (arrow A direction) of the housing 12 with respect to the base end of the holder 32, and is disposed at the center of the resin mold portion 14 to be described later. An annular first groove portion 34 to be engaged with a resin mold portion 14 to be described later is formed. A fuel supply unit 16 is provided on the base end side (arrow A direction) of the fixed core 26.

  As shown in FIGS. 1 to 3, the bobbin 30 is formed in a cylindrical shape, for example, and is provided between the fixed core 26 and the holder 32, and the base end side (in the direction of arrow A) of the amplification member 36 is An engagement pin 38 that is engaged with the other end is formed. Further, on the outer peripheral side of the bobbin 30, a coil 28 is wound in a concave portion recessed in the radial inward direction, and as shown in FIG. The 2nd signal transmission member 70 which comprises the signal transmission part 24 mentioned later is provided so that it may become the outer peripheral side.

  On the other hand, a cylindrical nonmagnetic member 40 is provided between the bobbin 30 and the fixed core 26 (see FIG. 3).

  The ends of the coils 28 extend toward the base end side (in the direction of arrow A) of the bobbin 30 and are connected to the ends of the pair of drive terminals 42, respectively. Is energized to generate magnetic force. As a result, the movable core is displaced inside the bobbin 30 under the exciting action of the coil 28 in the housing 12, and fuel injection is performed by displacing the needle 44 connected to the movable core toward the base end side (in the direction of arrow A). A valve body (not shown) provided in the portion 18 is opened to inject fuel.

  The holder 32 is formed, for example, in a hollow shape, and its outer peripheral surface is formed with a substantially constant diameter, and an annular second groove portion 46 that is recessed radially inward is formed on the outer peripheral surface on the base end side. The And the resin mold part 14 mentioned later is engaged with this 2nd groove part 46, and the holder 32 is fixed with respect to the resin mold part 14. FIG.

  As shown in FIGS. 2 and 3, the bobbin 30 is housed in the holder 32, and a housing portion 48 is formed that widens radially outward from the inner circumferential surface formed in a substantially circular cross section. The The storage portion 48 has, for example, a predetermined width and extends radially outward, and is formed at a position on the coupler portion 52 side of the resin mold portion 14 to be described later. The second signal transmission member 70 constituting the signal transmission unit 24 is accommodated inside the storage unit 48 via the bulging portion 30 a of the bobbin 30 corresponding to the storage unit 48. In other words, the holder 32 is formed such that the radial thickness D (see FIG. 3) is thin only in the portion having the storage portion 48.

  Further, the amount of widening outward of the storage portion 48 in the radial direction is set so that at least the second signal transmission member 70 stored inside does not come into contact with the coil 28.

  As shown in FIG. 1, the resin mold portion 14 is formed on the outer peripheral side of the housing 12 by molding from a resin material, for example, and is formed from a cylindrical main body 50 and a base end of the main body 50. A coupler portion 52 projecting sideways and a connecting portion 54 for connecting the main body portion 50 and the coupler portion 52 are provided. Then, by molding the resin mold portion 14 with a resin material, the first groove portion 34 of the fixed core 26 provided at the center of the main body portion 50 and the first of the holder 32 provided at the front end side of the main body portion 50. The melted resin material enters the two groove portions 46, and the housing 12 is fixed to the center and the tip of the resin mold portion 14.

  The coupler part 52 is formed in, for example, a rectangular cross section and protrudes obliquely upward so as to incline by a predetermined angle with respect to the axial direction (arrow A, B direction) of the main body part 50. The coupler portion 52 has an open end and a space inside. The power supply terminal 58 and the signal terminal 22 of the amplification member 36 described later, and a pair of drive terminals 42 for energizing the coil 28. Are provided so as to be exposed.

  For example, the amplifying member 36 is provided inside the resin mold portion 14 and covers the substrate 56, the power supply terminal 58 and the signal terminal 22 electrically connected to the substrate 56, and the entire substrate 56. And is provided for the purpose of amplifying the detection value (detection signal) detected by the sensor 20 and outputting it from the signal terminal 22 to the outside.

  The power terminal 58 and the signal terminal 22 are, for example, one end of the signal terminal 22 in a state where the signal terminal 22 is disposed substantially at the center along the width direction of the substrate 56 and the pair of power terminals 58 are disposed on both sides of the signal terminal 22. The part is electrically connected to the substrate 56 by solder or the like.

  The sealing portion 60 is formed of, for example, a resin material, and the tips of the substrate 56, the power supply terminal 58, and the signal terminal 22 are connected in a state where the tips of the power supply terminal 58 and the signal terminal 22 are connected to the substrate 56. It is formed to cover. Thereby, the connection of the power supply terminal 58 and the signal terminal 22 to the substrate 56 is firmly held by the sealing portion 60.

  And when the amplification member 36 molds the resin mold part 14, the engagement pin 38 of the bobbin 30 is inserted into the sealing part 60, so that the substrate 56 and the sealing part 60 correspond to the connection part 54, respectively. The second signal transmission member 70 of the signal transmission unit 24 with respect to the substrate 56 is simultaneously molded with the power supply terminal 58 and the signal terminal 22 in a position corresponding to the coupler unit 52. Are electrically connected.

  By connecting a connector (not shown) to the coupler portion 52, power is supplied to the coil 28 of the housing 12 through the drive terminal 42, and the amplifier member 36 and the sensor 20 are energized through the power terminal 58. At the same time, the detection value detected by the sensor 20 is output to the outside as an electric signal from the signal terminal 22 through the signal transmission unit 24.

  As shown in FIG. 1, the fuel supply unit 16 has, for example, a supply passage (not shown) through which fuel is supplied inside the fixed core 26, and the base end side (in the direction of arrow A) of the fuel injection valve 10. A fuel pipe (not shown) is connected to the end of the supply passage that is open at (). Then, the fuel supplied through the fuel pipe is supplied to the fuel injection unit 18 side (in the direction of arrow B) provided on the tip side through the supply passage.

  The fuel injection unit 18 includes a valve housing 62 connected to the front end of the housing 12 and a valve body (not shown) built in the front end of the valve housing 62. The fuel is supplied from the fuel supply unit 16 to the inside of the valve housing 62, and the valve body moves toward the base end side (in the direction of arrow A) under the excitation action of the coil 28. Is injected into the combustion chamber.

  As shown in FIGS. 1 and 2, the valve housing 62 is made of, for example, a metal material and has a flange portion 64 that closes the distal end of the housing 12, and a distal end side (in the direction of arrow B) from the flange portion 64. And a cylindrical portion 66 that extends in a straight line toward the end, and a cylindrical sensor 20 is press-fitted and fitted to the outer periphery of the distal end of the cylindrical portion 66.

  As shown in FIG. 1, the sensor 20 includes, for example, a piezoelectric element (not shown) therein, and a connection terminal connected to the piezoelectric element is exposed on the base end side (in the direction of arrow A). . Further, a holding portion 78 of a cover member 76 described later contacts the outer peripheral surface of the sensor 20. For example, the inner peripheral side of the tip of the sensor 20 is coupled to the valve housing 62 by welding all around.

  The signal transmission unit 24 is provided on the outer peripheral side of the valve housing 62 and is housed in the first signal transmission member 68 connected to the sensor 20 and the holder 32 of the housing 12, and the first signal transmission member 68 and the signal terminal. 2 and a second signal transmission member 70 for connecting to the second signal transmission member 70.

  The first signal transmission member 68 is formed, for example, in a cylindrical shape from a resin material, and an insulator 72 provided on the outer peripheral side of the tube portion 66 in the valve housing 62 and a first conductivity provided in the insulator 72. Layer 74. The first conductive layer 74 is electrically connected to the connection terminal of the sensor 20 by, for example, solder.

  The insulator 72 is made of, for example, a resin material such as a heat-resistant resin, and the base end side (in the direction of arrow A) is expanded so as to cover the cylindrical portion 66 and the flange portion 64 corresponding to the shape of the valve housing 62. It is formed with a diameter. In the center of the thickness of the insulator 72 along the radial direction, a first conductive layer 74 made of, for example, a plating layer is formed. The first conductive layer 74 is formed on the insulator 72 with a substantially constant thickness. A cylindrical shape is formed along. The tip of the insulator 72 is press-fitted into the sensor 20 together with the cylindrical portion 66 of the valve housing 62.

  On the other hand, on the outer peripheral side of the insulator 72, for example, a cover member 76 formed in a cylindrical shape from a metal material is mounted so as to cover the insulator 72, and the cover member 76 has the shape of the valve housing 62. Correspondingly, the base end side (in the direction of arrow A) is formed so as to expand in diameter so as to cover the cylindrical portion 66 and the flange portion 64. A holding portion 78 that holds the outer peripheral surface of the proximal end side of the sensor 20 is formed at the distal end of the cover member 76.

  The second signal transmission member 70 is made of, for example, a resin material, has a plate shape having a predetermined length along the axial direction (arrows A and B directions), and is stored in the storage portion 48 in the holder 32. A second conductive layer 80 is formed along the axial direction (the direction of arrows A and B), and is formed from a material that can be energized.

  The second conductive layer 80 is formed of, for example, a plating layer, and extends from the distal end to the proximal end along the axial direction (arrow A, B direction) of the second signal transmission member 70 with a substantially constant thickness. .

  As shown in FIGS. 1 and 2, a first connection portion 82 that protrudes in a direction orthogonal to the axis is formed at the tip of the second signal transmission member 70, and the first connection portion 82 is a first signal. The base end of the transmission member 68 is electrically connected by solder or the like.

  On the other hand, as shown in FIG. 1, the second signal transmission member 70 has a second connection portion 84 having a small diameter that is reduced in diameter with respect to the distal end side. A part of the second conductive layer 80 is annularly exposed along the outer peripheral surface. Then, the second connection portion 84 is inserted into a connection hole (not shown) formed in the substrate 56 of the amplification member 36 and is electrically connected by solder or the like, so that the second signal transmission member 70 is amplified. And electrically connected.

  Accordingly, the sensor 20 and the amplification member 36 (signal terminal 22) are electrically connected to each other via the first and second signal transmission members 68 and 70.

  The in-cylinder pressure sensor-equipped fuel injection valve 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described.

  During operation of the internal combustion engine (not shown), the coil 28 is energized from the drive terminal 42 of the fuel injection valve 10 by a control signal from the electronic control unit, and the needle 44 moves to the proximal end side when the coil 28 is excited. Along with this, the valve body of the fuel injection unit 18 is opened. As a result, the high-pressure fuel supplied to the supply passage of the fuel supply unit 16 is directly injected into the combustion chamber of the internal combustion engine via the fuel injection unit 18. At this time, the sensor 20 is applied with a pressure (in-cylinder pressure) in the combustion chamber, so that the piezoelectric element generates a voltage corresponding to the pressure and outputs it as a detection signal.

  This detection signal is output to the amplification member 36 through the sensor 20, the first signal transmission member 68, and the second signal transmission member 70. After the detection signal is amplified in the amplification member 36, the detection signal is passed through the signal terminal 22. Output to the electronic control unit. For example, in the electronic control unit, the pressure in the combustion chamber is calculated from the amplified detection signal, and is used for combustion control based on the pressure.

  As described above, in the present embodiment, in the housing 12 constituting the fuel injection valve 10, the holder 32 that houses the bobbin 30 is widened radially outward with respect to the inner peripheral surface thereof, and is molded with resin. A storage part 48 on the coupler part 52 side of the part 14 is provided, and the second signal transmission member 70 of the signal transmission part 24 is stored in the storage part 48. Therefore, since the signal transmission part 24 can be suitably accommodated inside the holder 32 without enlarging the outer diameter of the holder 32, the sensor 32 can be accommodated through the signal transmission part 24 accommodated inside while preventing an increase in size. The detection signal from 20 can be output to the outside.

  Moreover, although the holder 32 functions as a magnetic circuit, since only a part of the holder 32 is configured as the storage portion 48, the magnetic force by the magnetic circuit is ensured and the attraction force of the movable core is prevented from being lowered. .

  Furthermore, the storage portion 48 can be easily provided by partially increasing the inner peripheral diameter of the bobbin 30.

  In addition, the fuel injection valve with an in-cylinder pressure sensor according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Fuel injection valve with cylinder pressure sensor 12 ... Housing 14 ... Resin mold part 16 ... Fuel supply part 18 ... Fuel injection part 20 ... Sensor 24 ... Signal transmission part 30 ... Bobbin 32 ... Holder 36 ... Amplifying member 48 ... Storage part 52 ... coupler part 68 ... first signal transmission member 70 ... second signal transmission member 82 ... first connection part 84 ... second connection part

Claims (3)

A sensor for detecting the in-cylinder pressure in the combustion chamber is provided at the end of the fuel injection valve that directly injects fuel into the combustion chamber of the internal combustion engine, and the valve body is driven under the energization action of the coil assembly including the coil. In the fuel injection valve with in-cylinder pressure sensor,
The coil assembly is covered with a cylindrical housing that forms a magnetic path, and is expanded in the radial direction from the inner peripheral surface to the housing, and transmits the in-cylinder pressure detected by the sensor as a detection signal. A fuel injection valve with an in-cylinder pressure sensor, characterized in that a storage portion for storing a signal transmission member is provided. The fuel injection valve with an in-cylinder pressure sensor according to claim 1,
The fuel injection valve with an in-cylinder pressure sensor, wherein the storage portion is formed by partially expanding the inner peripheral surface of the housing. The fuel injection valve with an in-cylinder pressure sensor according to claim 1 or 2,
The fuel injection valve with an in-cylinder pressure sensor, wherein the housing portion is formed at a position on a signal terminal side where the detection signal from the signal transmission member is output in the housing.

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