JP4774420B2 - Intake throttle control device for internal combustion engine - Google Patents

Description

  The present invention uses the fact that the inductance between the conductor attached to the rotating shaft of the rotating body and the coil conductor attached to the stator facing the rotating body changes according to the positional relationship between the two, The present invention relates to a rotation angle detection device that detects a rotation angle of a rotating body by detecting a rotation position of an attached conductor, and also relates to an intake throttle valve control device for an internal combustion engine equipped with such a rotation angle detection device.

  In addition, a motor-driven throttle valve controller that electrically controls the opening area of the air passage of the internal combustion engine with a throttle valve driven by a motor, and the rotation angle of the throttle valve (rotation angle of the throttle valve shaft) are detected. The present invention relates to a rotation angle detection device.

  As a so-called non-contact type rotation angle detection device that detects the position or rotation angle of a rotating body based on a change in inductance, a device described in Japanese Patent Application Laid-Open No. 2003-254882 is known.

  US Pat. No. 6,888,600 is known as an intake throttle valve control device for an internal combustion engine equipped with this type of non-contact type rotation angle detection device.

  This prior art includes an excitation conductor portion fixed to a throttle valve shaft, which is a rotation detection body, and an excitation conductor portion arranged to face the excitation conductor portion.

  The exciting conductor portion is provided on the surface of the substrate attached to a resin cover as a case member that covers one end of the throttle valve shaft.

  The excitation conductor portion includes a plurality of radially extending radial conductor portions and inner connection conductor portions that connect the inner diameter sides of adjacent conductor portions and outer connection conductor portions that connect the outer sides of adjacent conductor portions. It consists of a continuous conductor pattern.

  The exciting conductor portion facing this is not specifically described in US Pat. No. 6,688,600, but generally includes an exciting coil conductor and a detecting coil conductor.

  An excitation current is generated in the excitation conductor on the rotating body (throttle valve shaft) side by the current passed through the excitation coil conductor attached to the cover member, and this excitation current is received by the detection coil conductor attached to the cover member. The inductance between the excitation conductor and the excitation coil conductor changes depending on the rotational position of the rotating body, and the value of the excitation current changes accordingly. This change is caught by the detection coil conductor, and the rotation angle of the rotating body is determined.

JP 2003-189546 A US Pat. No. 6,886,800

  In this type of conventional non-contact rotation angle detection device, the excitation coil and detection coil conductor mounted on the case member (resin cover of the intake throttle valve control device of the internal combustion engine) are sulfur gas, sulfur-based compound gas, nitrogen There has been a problem of corrosion when exposed to oxide gas, COx gas, or chlorine gas.

  Cover the excitation coil and detection coil conductor on the surface of the substrate with a resin shielding material in order to protect the excitation conductor (excitation coil conductor) and detection coil conductor on the surface of the substrate from the space where such corrosive gas exists. Has been proposed. And this resin-made shielding material is fixed to the case member with a silicon adhesive.

  However, since the conventional silicon adhesive has a high gas permeability, it is insufficient to protect the exciting conductor (exciting coil conductor) and the detecting coil conductor on the substrate from corrosive gas.

  An object of the present invention includes an inductance type rotation angle detection device and an inductance type rotation angle detection device that protect the excitation conductor (excitation coil conductor) and the detection coil conductor on the substrate from corrosive gas and have sufficient reliability. Another object of the present invention is to obtain an intake throttle valve control device for an internal combustion engine.

  In order to achieve the above object, the present invention provides a shielding member for isolating the substrate-like excitation conductor (excitation coil conductor) and the detection coil conductor from surrounding corrosive gas.

  Specifically, the shielding member may be a resin coating.

  Further, the shielding member may be a resin-made shielding cover. When this cover is adhered, at least the corrosive gas can be trapped or adsorbed to the adhesion portion facing the space where the corrosive gas exists. It is configured to adhere with an adhesive.

  More specifically, the filler may be activated carbon. The right side of the adhesive seat may be a silicon adhesive.

  According to the present invention, an adhesive capable of coating an excitation conductor (excitation coil conductor) and a detection coil conductor on a substrate with resin coating, covering with a resin shielding cover, and trapping or adsorbing corrosive gas. (For example, a silicon adhesive containing a filler capable of trapping or adsorbing corrosive gas), the corrosive gas is not permeated to the excitation conductor (excitation coil conductor) and the detection coil conductor.

  In other words, the corrosive gas is shielded, or the corrosive gas is shielded with a resin coating, or chemically reacted in an adhesive that bonds the resin cover. The detection coil conductor can be protected.

  In the present invention configured as described above, the rotation angle detection device with improved reliability against the corrosive gas of the inductance type non-contact rotation angle detection device, or the motor-driven throttle valve control device (internal combustion engine) having the same Intake throttle valve control apparatus) is obtained.

  Embodiments of the present invention will be described below with reference to the drawings.

  An embodiment of the rotation angle detection apparatus according to the present invention will be described with reference to FIGS.

  As shown in FIGS. 1, 2, and 3, a low-cylindrical (cup-shaped) holder 1 </ b> B made of a resin or a molded body of resin and metal is attached to the tip of the rotating shaft 1 </ b> A. A disc 1C made of an insulating material is fixed to the front end surface of the holder 1B by adhesion. An annular recess 1D is formed on the front end surface of the holder 1B. An adhesive is poured into the recess 1D, and the disk 1C is placed thereon and bonded.

  Grooves extending in the axial direction and convex shapes extending in the axial direction are alternately formed around the cylindrical portion of the holder 1B, and the inner peripheral surface of the rotating body 1A is convex with the grooves surrounding the holder 1B. On the other hand, the concavo-convex part is formed so as to constitute the fitting part 1F. The fitting portion 1E serves as a stopper around the holder 1B and also functions as positioning.

  The sensor case 2 </ b> A is provided with a protrusion 2 </ b> C, and is positioned when the fixed substrate 3 is installed.

  The sensor case 2A is provided with a groove 2B for applying a silicon adhesive. The silicon adhesive is poured into the groove 2B (for silicon application), and the sensor case 2A and the fixed substrate 3 are fixed. Silicone adhesive is applied to the outer periphery of the fixed substrate 3, around the three positioning holes, and around the center hole of the excitation conductor of the fixed substrate 3, and corrosive gas flows between the fixed substrate 3 and the sensor case 2A. I am trying not to.

  The silicon adhesive is an adhesive in which a filler having an adsorption function with respect to corrosive gases such as sulfur gas or sulfur-based compound gas, nitrogen oxide gas, COx gas, and chlorine gas is blended.

The adsorbent blended in the silicon adhesive is activated carbon, sulfurous acid gas (SO ₂ ), hydrogen sulfide gas (H ₂ S), sulfur single gas (S ₂ , S ₃ , S ₄ , S ₆ , S ₈ , Sx ring state), and carbon disulfide gas (CS ₂ ) with high specificity of adsorption.

  The upper surface of the fixed substrate 3 is coated with a polyolefin resin material 2C, which is exposed to moisture, chemicals, resin powder or metal powder that is wear powder of gears and bearings, and prevents oxidation, corrosion, or electromagnetic deterioration. Can do.

  Next, an example in which the inductance-type non-contact rotation angle detection device is applied to a motor-driven intake throttle valve control device for a gasoline engine will be described with reference to FIG.

  An intake passage 1 (hereinafter referred to as a bore) and a motor housing 20A for housing the motor 20 are molded together in an aluminum die-cast throttle valve assembly (hereinafter referred to as a throttle body) 6.

  A metal rotating shaft (hereinafter referred to as a throttle valve shaft) is disposed on the throttle body 6 along one diameter line of the bore 1. Both ends of the throttle valve shaft 3A are supported by bearings 9 and 10. The bearing is press-fitted and fixed to bearing boss portions 7 and 8 provided on the throttle body 6.

  Thus, the throttle valve shaft 3A is rotatably supported with respect to the throttle body 6. On the throttle valve shaft 3A, a throttle valve 2 made of a metal disc is inserted into a slit provided on the throttle valve shaft 3A, and fixed to the throttle valve shaft with screws 4 and 5.

  Thus, when the throttle valve shaft 3A rotates, the throttle valve 2 rotates, and as a result, the area of the intake passage changes and the intake air flow rate to the engine is controlled.

  The motor housing 20 </ b> A is formed substantially in equilibrium with the throttle valve shaft 3 </ b> A, and the motor 20 constituted by a brush type DC motor is inserted into the motor housing 20 </ b> A and the bracket of the motor 20 is screwed to the side wall of the throttle body 6. It is fixed by that.

  The opening of the bearing boss 8 is sealed with a cap 11, and the bearing boss 7 has an airtight function on the bearing 9 itself, and is configured to keep airtight. The retainer 12 is used to fix the bearing 9.

  As a result, leakage of air from the bearing portion or entry of gas and foreign matter from the intake passage is prevented.

  A metal motor gear 22 having the smallest number of teeth is fixed to the rotating shaft end of the motor 20. A reduction gear mechanism and a spring mechanism for rotationally driving the throttle valve shaft 3A are collectively arranged on the side surface of the throttle body where the motor gear 22 is provided. These mechanisms are covered with a resin cover (hereinafter referred to as a gear cover) fixed to the side surface of the throttle body 6. The so-called gear housing chamber 30 covered with the gear cover is provided with the inductance-type non-contact rotation angle detection device (hereinafter referred to as a throttle sensor) described with reference to FIGS. 1 to 3, and rotates the throttle valve shaft 3A. The angle, and consequently the opening of the throttle valve 2, is detected.

  In the motor-driven throttle valve control device to which the rotation angle device described above is applied, the bearing 9 basically keeps the airtightness in the bore. However, in the unlikely event that gas enters from the bore, In particular, the signal sensor conductor and the excitation conductor of the throttle sensor can be protected from the adhesion of various chemical substances and grease and gear wear powder.

  A throttle gear 13 is fixed to the end of the throttle valve shaft 3A on the gear storage chamber 30 side. The throttle gear 13 includes a metal plate 14 and a resin material gear portion 15 formed by resin molding of the metal plate 14.

  The metal plate 14 has holes. A thread groove is formed around the tip of the throttle valve shaft 3A. The tip of the throttle valve shaft 3A is inserted into the hole of the metal plate 14, and the nut 21 is screwed into the threaded portion to fix the metal plate 14 to the throttle valve shaft 3A. Thus, the metal plate 14 and the resin gear portion 15 molded there rotate integrally with the throttle valve shaft 3A.

  When the motor is de-energized as viewed from the fully closed position of the return spring 16 and the throttle valve, which energizes the spring force in the closing direction to the throttle valve 2 formed by a string spring between the back surface of the throttle gear 13 and the side surface of the throttle body 6. A default spring 17 for biasing the spring force is sandwiched between a predetermined opening (hereinafter, this opening is defined as a default opening) larger than the fully closed position. When the motor is not energized, it is configured to maintain the default opening, and it is possible to secure an air flow rate that allows the vehicle to travel at a certain speed even during fail-safe.

  Between a gear 22 attached to the rotating shaft of the motor 20 and a gear 25 fixed to the throttle valve shaft 3A, a gear shaft 24 made of a metal material press fitted and fixed to the side surface of the throttle body 6 is rotatably supported. The intermediate gear 23 is engaged. The intermediate gear 23 includes a large-diameter gear 23A that meshes with the gear 22 and a small-diameter gear 23B that meshes with the throttle gear 13. Both gears are integrally formed by resin molding. These gears 22, 23A, 23B, and 15 constitute a two-stage reduction gear mechanism.

  Thus, the rotation of the motor 20 is transmitted to the throttle valve shaft 3A via this reduction gear mechanism.

  A fixed substrate 27 of a throttle sensor is fixed to the gear cover 25 with a silicon adhesive 33 at a position facing the conductive plate 18.

  When a substrate on which the electronic components of the sensor are mounted is disposed in the gear housing chamber 30, the gear housing chamber 30 is exposed to dew condensation caused by wear powder of mechanical parts such as gears and the expansion and compression of air in the gear housing chamber 30.

Furthermore, considering that a throttle body is mounted on the intake pipe of the internal combustion engine, chemical substances such as SO ₂ (sulfur dioxide), S ₈ (sulfur), and O ₃ (ozone) pass through the bearing 9 from the bore 1 and are stored in the gear. In some cases, it flows into the chamber 30.

  In order to solve the above problems, the present embodiment applies a resin coating material 35 to the surface of the fixed substrate 27 to protect the surface of the fixed substrate 27 as shown in FIG. Alternatively, by fixing with a silicon adhesive that can be adsorbed, corrosion from the back surface of the substrate can be prevented, and the above problem can be overcome. As a result, it is possible to provide a throttle body including a highly reliable inductance type non-contact sensor with a reduced number of parts.

  In the above embodiment, an opening is provided in the resin cover that covers the gear of the motor, a substrate is attached so as to close the opening, and an excitation conductor (excitation coil) is provided on the surface of the substrate on the gear side (excitation conductor side attached to the rotating body). Conductor) and detection coil conductor, and at this time, a resin shielding member is sandwiched between the substrate and the cover member, and the excitation conductor (excitation coil conductor) and detection coil conductor are inserted from the gear side space where corrosive gas exists. To seal.

  The substrate and the cover member, and the substrate and the resin shielding member are bonded by silicon resin as an elastic adhesive having viscoelasticity with activated carbon. This can reduce the possibility that the corrosive gas passes through the adhesive layer and reaches the exciting conductor (exciting coil conductor) and the detection coil conductor.

  The present invention can be widely applied to an inductance type rotation angle detector without being limited to this embodiment. In a general inductance-type rotation angle detection device, a resin-made shielding member that shields an excitation conductor (or detection conductor) on a substrate from outside air can be directly bonded on the substrate. At this time, the substrate and the shielding member made of a resin material are bonded by a silicon resin as an elastic adhesive having viscoelasticity with activated carbon. This can reduce the possibility that the corrosive gas passes through the adhesive layer and reaches the exciting conductor (or the detection conductor).

[Embodiment 1]
A case member to which a substrate is attached,
An exciting conductor portion that is disposed on the substrate and generates a magnetic field by applying a current,
An excitation conductor portion that is fixed to the rotation detection body and is arranged in a non-contact state with a space from the excitation coil portion, and generates an electric current according to the rotation position of the rotation detection body by electromagnetic action,
A rotation angle detecting device including a receiving conductor portion that is disposed on the substrate and generates a current corresponding to a current flowing through the excitation conductor,
The substrate is attached to the inner wall of the case member, and the case member and the substrate have different linear expansion coefficients, and are fixed with an elastic adhesive having viscoelasticity such as a silicon adhesive. An intake throttle valve control device for an internal combustion engine provided with a rotation angle detection device.

[Embodiment 2]
In what is described in embodiment 1,
The internal combustion engine provided with the rotation angle detecting device, wherein the silicon adhesive application portion is applied so that the back surface of the substrate is blocked from the internal space of the substrate mounting case when the through hole of the multilayer substrate is sealed Intake throttle valve control device.

[Embodiment 3]
In what is described in embodiment 1,
The substrate is attached to the inner wall of the case member, the excitation conductor portion and the reception conductor portion are positioned so as to face the excitation conductor portion, and a resin material coating is applied to the surface of the substrate. An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device.

[Embodiment 4]
In what is described in embodiment 3,
The resin coating is a polyolefin resin, acrylic resin, urethane resin, or fluororesin, and is exposed to moisture, chemicals, resin powder or metal powder that is wear powder of gears and bearings, An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device having a function of preventing corrosion or electromagnetic deterioration.

[Embodiment 5]
In what is described in embodiment 1,
A structure in which the case member and the substrate are joined using an adhesive having a function of adsorbing corrosive gas, or a sealant as an adhesive or sealant for bonding the gap or filling the gap. An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device.

[Embodiment 6]
In what is described in embodiment 1,
The substrate has a structure in which sulfur gas or a sulfur compound gas, nitrogen oxide gas, COx gas, chlorine gas, or the like is bonded using an adhesive containing a filler having an adsorption function with respect to corrosive gas. An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device.

  The effects of the embodiment are as follows.

  By coating the upper surface of the fixed substrate with a resin material, it can be exposed to moisture, chemicals, resin powder and metal powder that is wear powder of gears and bearings, and can prevent oxidation, corrosion or electromagnetic deterioration, Furthermore, by providing the fixing substrate and gear cover fixing adhesive with a function of trapping or adsorbing gas, the substrate can be protected from corrosive gas, and a highly reliable rotation angle detection device or the like. A motor-driven throttle valve control device having the above is obtained.

  The present invention can be widely applied to an inductance type rotation angle detection device. It can also be applied to this type of detection device that is mounted where it is necessary to protect the conductor from similar corrosive gases. Furthermore, the intake throttle valve device of the internal combustion engine can be applied not only to gasoline vehicles but also to diesel vehicles.

The principal part expanded sectional view of an inductance type non-contact-type rotation angle detection apparatus. The principal part expansion perspective view of an inductance type non-contact-type rotation angle detection apparatus. The principal part disassembled perspective view of an inductance type non-contact-type rotation angle detection device. Sectional drawing of the motor-driven throttle valve control apparatus used for a gasoline engine vehicle.

Explanation of symbols

1A Rotating body (also called rotating shaft)
1B, 19 Holder 1C Disc 1D Annular depression
1E Fitting part 2A Sensor case 2B (For silicon adhesive application) Groove 3, 27 Fixed substrate 1 Bore 2 Throttle valve 3A Throttle valve shaft 4, 5 Screw 6 Throttle body 7, 8 Bearing boss part 9, 10 Bearing 11 Cap 12 Retainer 13 Throttle gear 14 Metal plate 15 Resin gear 16 Return spring 17 Default spring 18 Conductive plate 20 Motor 21 Nut 22 Motor gear 23 Intermediate gear 24 Gear shaft 25 Gear cover 30 Gear housing chamber 32 Seal member 33 Silicon adhesive 35 Resin Coating material 36 Positioning pin

Claims (18)

A case member to which a substrate is attached,
An excitation conductor disposed on the substrate and generating a magnetic field by applying a current;
An excitation conductor that is fixed to the rotation detection body and is arranged in a non-contact state with a space from the excitation conductor, and generates a current corresponding to the rotation position of the rotation detection body by electromagnetic action;
A receiving conductor portion disposed on the substrate and sensitive to a current generated by the excitation conductor portion;
In what comprises
A rotation angle detecting device comprising a shielding member for isolating an exciting conductor portion and a receiving conductor portion on the substrate from a corrosive gas atmosphere. In claim 1,
The rotation angle detecting device, wherein the shielding member is a resin-made coating covering the exciting conductor portion and the receiving conductor portion on the substrate. In claim 2,
A rotation angle detection device comprising: a resin material shielding cover which is adhered to a substrate by an adhesive so as to surround an outer peripheral portion of the resin material coating. In what is described in claim 3,
The rotation angle detecting device, wherein the adhesive is a silicon adhesive. In claim 1,
An adhesive having a function of adsorbing corrosive gas between the resin material shielding plate and the substrate, wherein the shielding member is formed of a resin material shielding plate covering the exciting conductor portion and the receiving conductor portion on the substrate. Or the rotation angle detection apparatus characterized by sealing with the sealing material. In any one of claims 3 to 5,
The substrate is composed of a multilayer substrate;
The adhesive or the sealing material is applied so as to seal the through hole of the multilayer substrate,
The rotation angle detecting device, wherein the adhesive or the sealing material blocks the front and back of the substrate, and the accommodation space of the excitation conductor and the receiving conductor is blocked from the outside. In any of claims 2 or 3,
The rotation angle detector according to claim 1, wherein the resin coating is made of polyolefin resin, acrylic resin, urethane resin, or fluororesin. What is described in claim 5
The adhesive or sealing material having the function of adsorbing the corrosive gas has an adsorbing function for at least sulfur gas, sulfur-based compound gas, nitrogen oxide gas, COx gas, or chlorine gas having corrosive properties. A rotation angle detection device characterized by being an adhesive or a sealing material containing a filler having the same. An intake throttle valve control device for an internal combustion engine equipped with a rotation angle detection device,
Throttle body,
An intake passage formed in the throttle body;
A butterfly throttle valve that controls the cross-sectional area of the intake passage;
The throttle valve is attached, and includes a throttle valve shaft that is rotatably held by the throttle body,
A motor for applying a driving force to the throttle valve shaft;
A reduction gear that transmits the rotation of the motor to the throttle valve shaft;
The rotation angle detection device is constituted by the rotation angle detection device according to claim 1,
The case member is configured as a resin cover attached to the throttle body so as to cover one end of the throttle valve shaft and the reduction gear,
The rotation detection body is configured as the throttle valve shaft;
The substrate is attached to the inner wall of the resin cover;
A rotation angle detection device is provided, wherein the shield member is configured to isolate the excitation conductor portion and the reception conductor portion on the substrate from the space where the reduction gear is installed in the corrosive gas atmosphere. An intake throttle valve control device for an internal combustion engine. In claim 9,
An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device, wherein the shielding member is a resin material coating covering the exciting conductor portion and the receiving conductor portion on the substrate. The thing of Claim 10 WHEREIN:
An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device, comprising: a resin material shielding cover which is adhered to a substrate by an adhesive so as to surround an outer peripheral portion of the resin material coating. In claim 11,
An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device, wherein the adhesive is a silicon adhesive. In claim 9,
An adhesive having a function of adsorbing corrosive gas between the resin material shielding plate and the substrate, wherein the shielding member is formed of a resin material shielding plate covering the exciting conductor portion and the receiving conductor portion on the substrate. Alternatively, an intake throttle valve control device for an internal combustion engine provided with a rotation angle detection device that is sealed with a sealing material. In any one of claims 11 to 13,
The substrate is composed of a multilayer substrate;
The adhesive or the sealing material is applied so as to seal the through-hole of the multilayer substrate, and the adhesive or the sealing material blocks the front and back of the substrate to accommodate the excitation conductor and the receiving conductor portion. A rotation angle detection device characterized in that the space is blocked from the outside. In claim 10,
An intake throttle valve control device for an internal combustion engine having a rotation angle detection device, wherein the resin material coating is a polyolefin resin, an acrylic resin, a urethane resin, or a fluororesin. In claim 13,
The adhesive or sealing material having the function of adsorbing the corrosive gas is a silicon adhesive that is corrosive to at least sulfur gas, sulfur-based compound gas, nitrogen oxide gas, COx gas, or chlorine gas. An intake throttle valve control device for an internal combustion engine comprising a rotation angle detection device, characterized in that it is an adhesive containing a filler having an adsorption function. In any one of claims 8 and 16,
The adhesive is characterized by using an adhesive containing a filler having an adsorption function for at least sulfur gas, sulfur-based compound gas, nitrogen oxide gas, COx gas, or chlorine gas corrosive gas. And an intake throttle valve control device for an internal combustion engine provided with the rotation angle detection device. Claim 17
A rotation angle detection device or an intake throttle valve control device for an internal combustion engine provided with the rotation angle detection device, wherein the filler is activated carbon.

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