JP4490402B2 - Throttle device for internal combustion engine - Google Patents

Description

  The present invention relates to a throttle device for an internal combustion engine, and more particularly to an electronically controlled throttle device that controls opening / closing of a throttle valve by driving an electric actuator based on a control signal.

  Conventionally, in an electronically controlled throttle device that drives and controls an engine throttle valve with an electric actuator (eg, DC motor, stepping motor), the initial opening of the throttle valve when the engine key is off (in other words, when the electric actuator is not energized) A technique for making (default opening) larger than the fully closed position is known.

  Here, the fully closed position of the throttle valve does not mean a position where the intake passage is completely closed, and in particular, a throttle that performs idle speed control only with the throttle valve without providing a bypass passage that bypasses the throttle valve. The device is defined by dividing into a mechanical fully closed position and an electrical fully closed position described below.

  The mechanically fully closed position is the minimum opening position of the throttle valve defined by the stopper. This minimum opening position is a position slightly opened from the position where the intake passage is completely blocked in order to prevent the throttle valve from getting stuck. Is set. The electrical fully closed position is the minimum opening of the opening range used for control, and the opening is slightly larger than that based on the mechanical fully closed position by the drive control of the electric actuator. The position is set to a position (for example, a position about 1 ° larger than the mechanically closed position).

  In the electronically controlled throttle, the electrical fully closed position (minimum opening degree for control) and the idle opening degree (the opening degree necessary for idling speed control) do not necessarily coincide. This is because the idling engine speed has a wide opening because the throttle valve opening is feedback controlled based on the idling engine speed detection signal in order to maintain the target engine speed.

  As for the fully open position, there are a mechanical fully open position defined by the stopper and an electrical fully open position which is the maximum opening degree for control. Here, the simple fully closed position includes an electrical fully closed position in addition to a mechanical fully closed position. In normal control, the throttle valve is controlled between an electrical fully closed position (minimum opening degree for control) and an electrical fully open position (maximum opening degree for control). In this way, part of the throttle valve shaft does not collide with the stopper that determines the mechanically fully closed and fully opened position during the minimum and maximum opening control of the throttle valve, and mechanical fatigue and wear of the stopper and throttle parts. , Damage can be prevented, and galling to the stopper can be prevented.

  The default opening (that is, the initial opening when the engine key is off) is a position where the throttle valve is further opened (for example, from the mechanical fully closed position) than the fully closed position (mechanical fully closed position and electrical fully closed position) described above. 4 to 13 ° larger position).

  One reason for setting the default opening is to secure the air flow required for combustion in the pre-warm-up operation (cold start) when starting the engine without providing an auxiliary air passage (air passage that bypasses the throttle valve). Is mentioned. During idling, the throttle valve is controlled to be throttled from the default opening to a direction in which the opening becomes smaller than the default opening (however, the electrical fully closed position is the lower limit position).

  In addition to the default opening, even if the throttle control system breaks down, it can ensure self-running (limp home) or intake air flow to prevent engine stall. It meets demands such as preventing sticking.

  Various conventional examples of the default opening degree setting mechanism have been proposed. As known examples, for example, Japanese Patent Application Laid-Open No. 63-150449, US Pat. Japanese Patent Laid-Open No. 62-82238 and corresponding US Pat. No. 4,735,179, Japanese Patent Laid-Open No. 10-89096, Japanese Patent Laid-Open No. 10-131771, and the like.

  There are various types of default opening setting mechanisms. The following are examples of typical ones.

  One is to engage a default opening setting engagement element (default lever) fitted to the throttle valve so that it can rotate on the throttle valve shaft with an element fixed to the throttle valve via a spring. The default lever is rotated together with the throttle shaft between the default opening position and the throttle valve fully open position, and when the engine key switch is off, the default lever is brought into contact with the default stopper to increase the opening of the throttle valve. When maintaining the default opening and keeping the throttle valve below the default opening, disengage the throttle valve shaft from the default lever and move the throttle valve shaft in the closing direction against the spring force alone. There is a method to rotate with.

  On the other hand, the default lever and throttle valve shaft are rotated together from the throttle valve fully closed position to the default opening position, and when the engine key is turned off, the default lever is brought into contact with the default stopper. When the valve opening is maintained at the default opening and the throttle valve is set to the default opening or higher, the engagement between the throttle valve shaft and the default lever is released and the throttle valve shaft is opened in the opening direction. There is a method of rotating alone against this.

  The electronically controlled throttle device can perform the air flow rate control suitable for the operation of the internal combustion engine more precisely than the mechanical throttle device that transmits the depression amount of the accelerator pedal to the throttle valve shaft via the accelerator wire. The number of parts increases because of the provision of the actuator, default opening setting mechanism, and throttle sensor. Accordingly, it is desired to reduce the size and weight of the throttle body, simplify it, streamline manufacturing and adjusting operations, and further improve operational stability and accuracy.

  The object of the present invention is to solve the above-mentioned problems, and to reduce the size and weight of a throttle device equipped with an electric actuator, a gear mechanism, a default opening setting mechanism, etc., to streamline manufacturing and adjustment work, to improve operational stability and accuracy. There is to increase.

  The present invention is basically configured as follows.

According to the present invention, in the throttle device for an internal combustion engine having the default opening setting mechanism, an engagement element (default lever) for setting the default opening is rotatable relative to the throttle valve shaft at one end of the throttle valve shaft. A return spring that urges the throttle valve in the closing direction so as to sandwich the engagement element, and a default that urges the spring force toward the default opening when viewed from the fully closed position of the throttle valve. Opening setting springs (default springs) are arranged in opposition to the throttle valve shaft direction, and these springs are constituted by coiled twisted springs, and both surfaces of the engaging element are used for the return spring and default opening setting The springs of these springs are used to lock one end of these springs, and both springs have different coil diameters and are compressed in the axial direction. Is mounted, characterized in that the compressive stress F of the spring having a larger coil diameter and greater than the compression stress f of the smaller spring having a coil diameter. The compressive stress is a repulsive force of the spring generated when the spring is compressed.

  When the throttle valve shaft rotates in a specific range within the throttle valve opening range (for example, the default opening of the throttle valve to the electrically fully closed position or the default opening to the electrically fully opened position) Since the engagement with the engagement element is required to be independently rotated, the engagement element for setting the default opening can be rotated relative to the restriction valve shaft. It is mounted with “clear fit” on top.

  Therefore, there is a clearance between the outer periphery of the throttle valve shaft and the engagement element for setting the default opening. Therefore, the engagement element for setting the default opening degree swings (displaces) due to vibration or the like when in an unstable state. Even if the engagement element for setting the default opening is held by the spring compression force of the coiled return spring and the default spring, the compression stress of both is equal or the balance of both springs is poor The engagement element for setting the default opening is in an unstable state in which it is likely to swing, so that the default opening is distorted and smooth operation of the engagement element cannot be expected.

  In the present invention, in order to cope with this problem, the compression stress F of the spring having the larger coil diameter of the return spring and the default spring is set larger than the compression stress f of the spring having the smaller coil diameter. In this way, the compressive stress F having the larger coil diameter overcomes f and presses the engagement element in a stable state in one direction at a position near the outer diameter. It is possible to prevent the above-mentioned displacement and maintain an appropriate state, and the above-described problems can be prevented.

Preferably, a reduction gear for transmitting the power of the electric actuator to the throttle valve shaft is provided, and the final gear of the reduction gear is fixed by press-fitting to one end side of the throttle valve shaft protruding from the side wall surface of the throttle body. The press-fit fixed last stage gear can be brought into contact with a stopper that defines the mechanically closed position of the throttle valve by driving an electric actuator.

  According to the above configuration, the final stage gear of the reduction gear also serves as a movable side defining element that defines the mechanical fully closed position, and this defining element (final stage gear) is fixed to the throttle valve shaft by press fitting. Therefore, even when the reduction gear comes into contact with the fully closed stopper and an impact is applied, the position of the reduction gear with respect to the throttle valve shaft can always maintain a fixed relationship. Therefore, there is no deviation in the opening of the throttle valve that is determined based on the mechanical fully closed position, which contributes to maintaining control accuracy.

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

  First, the principle of an electronically controlled throttle throttle device with a default mechanism (throttle device for an automobile internal combustion engine) according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a perspective view schematically showing power transmission and a default mechanism of a throttle valve in this embodiment, and FIG. 2 is a principle explanatory view equivalently showing its operation.

  In FIG. 1, the amount of air in the direction of the arrow flowing through the intake passage 1 is adjusted according to the opening of a disc-shaped throttle valve (throttle valve) 2. The throttle valve 2 is fixed to the throttle valve shaft 3 by screws. At one end of the throttle valve shaft 3, a final gear (hereinafter referred to as a throttle gear) 43 of the reduction gear mechanism 4 that transmits the power of the motor (electric actuator) 5 to the throttle valve shaft 3 is attached.

The gear mechanism 4 includes a pinion gear 41 and an intermediate gear 42 attached to the motor 5 in addition to the throttle gear 43. The intermediate gear 42 includes a large-diameter gear 42a that meshes with the pinion gear 41 and a small-diameter gear 42b that meshes with the throttle gear 43. It is disguised.
The motor 5 is driven in accordance with an accelerator signal or a traction control signal relating to the depression amount of the accelerator pedal, and the power of the motor 5 is transmitted to the throttle valve shaft 3 via gears 41, 42, and 43.

  The throttle gear 43 is a sector gear, is fixed to the throttle valve shaft 3, and has an engaging side 43a for engaging with a protrusion 62 of the default lever 6 described below.

  The default lever 6 is used for a default opening setting mechanism (becomes an engaging element for setting the default opening), and is fitted to the throttle valve shaft 3 so as to be rotatable relative to the throttle valve shaft. ing. The throttle gear 43 and the default lever 6 have a spring 8 (hereinafter also referred to as a default spring) having one end 8 a engaged with a spring engaging portion 6 d of the default lever 6 and the other end 8 b provided on the throttle gear 43. The projection 62 on the default lever 6 side and the engagement side 43a on the throttle gear 43 side are urged through the default spring 8 so as to be attracted (engaged) with each other in the rotation direction. ing. When viewed from the fully closed position of the throttle valve, the default spring 8 biases the throttle valve shaft 3 and thus the throttle valve 2 in the default opening direction.

  One end (fixed end) 7a of the return spring 7 that applies a return force in the closing direction to the throttle valve 3 is locked to a spring locking portion 100a fixed to the throttle body 100, and the other free end 7b side is the default lever 6. The default lever 6 and the throttle gear 43 and the throttle valve shaft 3 engaged therewith are urged in the closing direction of the throttle valve.

  In FIG. 1, the protrusions 61 and 62 of the default lever 6 and the degree of protrusion of the spring locking portion 43b provided on the throttle gear 43 are exaggerated for the convenience of drawing the drawing. , 8 are used by being compressed and the spring length in the axial direction is shortened, so that they are formed by short projections corresponding thereto (see exploded views of FIGS. 16 and 17). Further, in FIG. 1, the spring locking portion 43b is provided at one end opposite to the tooth side of the throttle gear 43 so that the spring locking portion 43b can be easily seen, but actually, as shown in FIG. It is provided so as to be hidden behind (the back side). Although the locking structure of the one end 7b of the return spring 7 and the locking structure of the one end 8a of the default spring 8 are also shown in a simplified manner in FIG. 1, they are actually as shown in FIGS. . Details of the mounting structure of these return spring 7 and default spring 8 will be described later.

  The fully closed stopper 12 is for defining the mechanical fully closed position of the throttle valve 2. When the throttle valve 2 is rotated in the closing direction until reaching the mechanical fully closed position, the stopper fixed to the throttle valve shaft 3 is provided. One end of the locking element (here also serving as the throttle gear 43) abuts against the stopper 12 to prevent the throttle valve 2 from closing further.

  A stopper for setting a default opening (sometimes referred to as a default stopper) 11 determines the opening of the throttle valve 2 when the engine key is turned off (when the electric actuator 5 is turned off). This is for maintaining a predetermined initial opening (default opening) larger than (minimum opening for control).

  The spring locking portion 61 provided on the default lever 6 contacts the default stopper 11 when the throttle valve 2 is at the default opening, and further rotates in the direction in which the opening of the default lever 6 becomes smaller (closed direction). It also functions as a stopper abutment element that prevents this. The fully-closed stopper 12 and the default stopper 11 are constituted by adjustable screws (adjusting screws) provided on the throttle body 100. Actually, as shown in FIGS. 8 and 12, they are parallel at close positions. Or they are arranged in parallel so as to be position-adjustable from the same direction.

  The throttle gear 43 and the default lever 6 can be engaged and rotated together against the return spring 7 in an opening range equal to or greater than the default opening by attracting each other in the rotational direction via the spring 8 [FIG. (See (c)) In addition, in the opening range below the default opening, the default lever 6 is prevented from moving by the default stopper 11, and only the throttle gear 43 together with the throttle valve shaft 3 resists the force of the default spring 8. It is set to be rotatable [see FIG. 2 (a)].

  In the off state of the engine key, the default lever 6 is pushed back to the position where it abuts against the default stopper 11 by the force of the return spring 7, and the throttle gear 43 is connected to the return spring 7 via the protrusion 62 of the default lever 6. The throttle valve 2 is in a position corresponding to the default opening degree (see FIG. 2 (b)). In this state, the throttle gear (stopper locking element) 43 and the fully closed stopper 12 keep a predetermined distance.

  From this state, when the throttle valve shaft 3 is rotationally driven in the opening direction via the motor 5 and the gear mechanism 4, the default lever 6 rotates together with the throttle gear 43 via the engagement side 43a and the protrusion 62, and the throttle valve 2 is rotated. Opens to a position where the rotational torque of the throttle gear 43 and the force of the return spring 7 are balanced.

  On the other hand, when the driving torque of the motor 5 is weakened and the throttle valve shaft 3 is rotated in the closing direction via the motor 5 and the gear mechanism 4, the default lever 6 (protrusion 61) is in the throttle gear until it contacts the default stopper 11. When the default lever 6 contacts the default stopper 11 following the rotation of the throttle valve shaft 43 and the throttle valve shaft 3, the default lever 6 is prevented from rotating in the closing direction below the default opening. Below the default opening (for example, from the default opening to the electrically closed position for control), when power is applied to the throttle valve shaft 3 by the motor 5, only the throttle gear 43 and the throttle valve shaft 3 are moved to the default lever 6. Is engaged against the force of the default spring 8. The full-close stopper 12 that defines the mechanical full-close position of the throttle valve is configured to drive the motor 5 and contact the throttle gear 43 only when the control reference point is known. In typical control, the throttle gear 43 does not contact the fully closed stopper 12.

  In this default system, the spring force of the return spring 7 is effective beyond the default opening due to the presence of the default stopper 11, and therefore the spring of the return spring 7 is not affected by the spring force of the return spring 7 below the default opening. Since the spring force can be set, there is an advantage that the load of the default spring can be reduced, and consequently the torque required for the electric actuator can be reduced, and the electrical load on the engine can be reduced.

  In this embodiment, the return spring 7 and the default spring 8 are coiled torsion springs, the diameter of the return spring 7 is made larger than the diameter of the default spring 8, and these springs 7, 8 are the shafts of the throttle valve shaft 3. It is held around and arranged between the throttle gear 43 and the wall of the throttle body 100.

  The return spring 7 and the default spring 8 are opposed to each other in the throttle valve axial direction so as to sandwich the default lever 6, and are actually mounted by being compressed in the axial direction as shown in FIGS. Both sides of the default spring 8 serve as spring receivers for the return spring 7 and the default spring 8, and the ends 7 b and 8 a of these springs are locked, and the compressive stress of the spring with the larger coil diameter (here, the return spring 7). F is set larger than the compressive stress f of the spring having the smaller coil diameter (here, the default spring 8). The compressive stress is set in this way as follows.

  Since the default lever 6 is in a free state, that is, “clearance fit” with the throttle valve shaft 3, the fitting portion (between the outer periphery of the throttle valve shaft 3 and the inner periphery of the default lever 6) There is a gap. Therefore, even if the default lever 6 is held by the return spring 7 or the default spring 8, the compressive stress of the both is the same, or the coil diameter of either spring is reduced and the vicinity of the center of the default lever 6 is pressed. Then, the default lever 6 lacks stability, and therefore the default lever 6 may be tilted and attached.

  If the default lever 6 is not mounted in the correct state as described above, the operation of the default lever 6 may be hindered, the contact point with respect to the default stopper 11 may be incorrect, and the default opening setting may be incorrect. In order to cope with such a problem, in this embodiment, the diameter of the return spring 7 is increased to such an extent as to be applied to the flange 6b that forms the outer diameter of the default lever 6, and the compression stress F is compressed by the compression of the default spring 8. This is sufficiently larger than the stress f. In this way, the compressive stress F of the return spring 7 acts near the outer periphery (closer to the outer diameter) of the default lever 6, and the default lever 6 moves in one direction (here, the throttle gear 43 side) due to the relationship of F> f. ) With a uniform force, the default lever 6 can be mounted in a stable state (without tilting), and the smooth operation of the default lever and the accuracy of the default opening setting are guaranteed.

  FIG. 3 is a cross-sectional view of the electronically controlled throttle device according to the present embodiment perpendicular to the axial direction of the intake passage 1. FIG. 4 is a perspective view of the electronically controlled throttle device of FIG. FIG. 5 is a cross-sectional view of the electronically controlled throttle device of FIG. 3 in the axial direction of the intake passage 1, FIG. 6 is a perspective view of the electronically controlled throttle device of the present embodiment, FIG. FIG. 7 is a perspective view showing the electronic control throttle device with the gear cover removed, FIGS. 8 and 9 are perspective views with different angles, FIG. 10 is a top view of the electronic control throttle device, and FIG. Fig. 12 is a view of the gear installation portion of the electronically controlled throttle device as seen from the outside with the gear cover removed, Fig. 12 is an explanatory view showing the state of attachment of the fully closed stopper and the default stopper, Partially shown Figure is a sectional view taken along line B-B of (b) is (a). FIG. 13 is a diagram showing the positional relationship between the intake passage 1 and the motor case 110 of the electronically controlled throttle device according to this embodiment, and is a cross-sectional view taken along the line CC in FIG. 6, and FIG. FIG. 15 is an exploded perspective view of the electronically controlled throttle device according to this embodiment, and FIGS. 16 and 17 are exploded perspective views showing a part of FIG. 15 in an enlarged manner.

  As shown in these drawings, a gear installation space 102 for accommodating the gear mechanism 4 is formed on one side wall of the throttle body 100, and a portion 106 of the gear installation space 102 is deeply recessed, and the throttle valve shaft is inserted into the recess 106. A bearing boss 101 that houses one of the three bearings 20 is provided. The bearing 20 is sealed by a seal member 18 supported by the seal retainer 19.

  The return spring 7 is a coil-shaped twisted screw, and most of the return spring 7 is disposed around the bearing boss (annular recess 106), and one end (fixed end) 7a is bent outward and provided in the recess 106 on the throttle body side wall. A protrusion 61 (see FIG. 17) provided on the default lever 6 with the other end 7b bent outwardly while being engaged with the spring locking portion 100a (see FIGS. 1, 3, 9, and 11). ) Is biased to the default lever 6 in the closing direction of the throttle valve. In this embodiment, one end 7b of the return spring 7 is provided with a locking hole 61a in the projection 61 of the default lever 6 as shown in FIG. 17, and the return spring one end 7b is locked in the locking hole 61a. It is hard to come off.

  As is apparent from FIGS. 3 to 5 and FIGS. 17 and 16, the throttle gear 43 has a throttle valve shaft insertion boss 43c formed only on one surface that receives one end of the default spring 8. The default lever 6 is also formed with a throttle valve shaft insertion boss 6f so as to face the boss 43c, and a default spring 8 is disposed around both the bosses 43c and 6f.

  The default spring 8 of this example is also a coil if it is twisted, and as shown in FIG. 16, one end 8a is bent to the inner diameter side and locked in a groove 6d provided in the boss 6f of the default lever 6, and the other end 8b. Is bent to the outer diameter side and locked to a locking projection 43b provided inside the throttle gear 43 as shown in FIG.

  The throttle valve shaft insertion hole 43d provided with the boss 43c of the throttle gear 43 has at least one plane, and here, it is a square hole having two parallel planes or a shape close to this, and one end 3a of the throttle valve shaft 3 is formed. The cross section has a shape similar to the throttle valve shaft insertion hole 43d, and the throttle gear 43 is fixed to one end of the throttle valve shaft 3 by press-fitting.

  The default lever 6 includes a dish-shaped resin portion 6a formed of reinforced plastic and a metal flange portion 6b provided on the periphery thereof (FIGS. 3 to 5, FIG. 16, FIG. 17). The resin portion 6a and the flange portion 6b are integrated by embedding the inner edge of the flange portion 6b in the outer periphery of the resin portion 6a by molding the resin portion 6a, and the protrusions 61 and 62 are formed by processing the flange portion 6b. Is provided. All of the default levers 6 may be formed of resin or metal plate.

  In this embodiment, the compressive stress F of the return spring 7 is received by the flange portion 6 b of the default lever 6. As shown in FIG. 16, the resin portion 6a has a boss 6f around the hole 6e through which the throttle valve shaft passes, and an annular groove 6C into which one end of the default spring 8 is fitted around the boss 6f. The bottom surface of the groove 6C receives the compressive stress f of the default spring 8 and has a relationship of F> f as described above.

  Through this default spring 8, the throttle gear 43 fixed to the throttle valve shaft 3 and the default lever (engagement element for setting the default opening) 6 are attracted in a direction in which they are engaged with each other in the rotational direction.

  A male screw is cut at one end of the throttle valve shaft 3 and the default lever 6, the default spring 8, and the throttle gear 43 are attached, and then the nut 17 is tightened via the spring washer 16. In this embodiment, the return spring 7 and the default spring 8 that are in a relationship of compressive stress F> f are compressed by the pressure input of the throttle gear 43. The throttle gear 43 may be fixed by tightening with the nut 17 instead of press fitting. In this case, the return spring 7 and the default spring 8 are compressed by the tightening force of the nut.

  The return spring 7 and the default spring 8 are coated with a coating that reduces the coefficient of friction to reduce friction, for example, a tetrafluoroethylene resin. The main purpose of this coating is to reduce the friction with the other party (the part that receives the springs 7 and 8 and the part where the spring is in contact during torsion, such as the boss), and the movement of the throttle valve by the motor is smooth. It is to reduce motor power consumption during operation.

The gear installation space 102 provided on the entire side wall of the throttle body 100 has an edge 104 formed integrally with the throttle body 100 around the gear installation space 102, and this edge 104 becomes a frame for attaching the gear cover. When the height H of the frame 104 is viewed from the bottom surface of the gear installation space 102 as shown in FIG. 4, the height is lowered to be lower than the mounting height h of the reduction gear mechanism 4. Yes. The height h ′ of the side wall 105 of the gear cover 103 is increased by the amount that the frame (the edge 104) is lowered in this way, so that the volume in the depth direction in the gear cover 103 is increased and the gear cover 103 reduces the reduction gear. The mechanism 4 is covered. This configuration eliminates the need to provide a gear case having an enclosure wall higher than the gear mechanism mounting height on the throttle body side wall as in the prior art. 103 is supplemented. As a result, the die-cast metal throttle body 100 can be reduced in size and weight can be reduced.

  In the present embodiment, the height of the pinion 41, the intermediate gear 42a, and the throttle gear 43 of the reduction gear 4 is set higher than that of the frame 104 by reducing the height of the gear cover mounting frame 104. Therefore, since the throttle gear 43 protrudes from the frame 104, the throttle gear 43 cannot be received even if the fully closed stopper 12 is provided on this frame. Therefore, a protrusion 102a for attaching the full-close stopper 12 at a position covered by the gear cover 103 is set integrally with the throttle body, and this protrusion 102a is provided beyond the height of the frame 104, and the full-close stopper 12 is provided on the protrusion 102a. Is arranged in accordance with the mounting height of the throttle gear 43.

Since the default lever 6 is at a lower position than the frame 4, the default stopper 11 has a hole 100c in the side wall of the throttle body 100 as shown in FIG. 12, and is parallel (substantially parallel) to the fully closed stopper 12 through this hole 100c. Are arranged in a row).
As shown in FIG. 13, the motor 5 used in the electric actuator is formed with two flat (planar) surfaces 51a and 51b facing the yoke 51 constituting the motor housing, and a motor case 110 for housing the motor is provided. It has flat inner surfaces 110a and 110b that match the shape of the motor housing, and is arranged on the side wall of the throttle body 100 so as to intersect a line perpendicular to the throttle valve shaft 3. The axial direction of the motor case 110 faces the same direction as the throttle valve shaft 3.

  By using the motor 5 having such a flat surface, the motor case 110 integrated with the throttle body 100 is also flattened and contributes to the miniaturization of the entire throttle body. Furthermore, in this embodiment, the motor case 110 Of the flat inner surfaces (planes) facing each other, all or most of one inner surface 110b constitutes the outer wall surface of the intake passage 1 on the downstream side from the idle opening position for control of the throttle valve 3. ing. Here, as an example, all or most of the flat inner surface 110b constitutes the outer wall surface of the intake passage on the downstream side of the electrical fully closed position for controlling the throttle valve. Further, the flat inner surface 110b is formed so as to be recessed from the outer wall surface of the surrounding intake passage, and as shown in FIG. 14, the wall of the 110b side wall adjacent to the intake passage 1 in the motor case 110 is formed. The motor case inner surface 110b is made closer to the intake passage side by reducing the thickness.

  The motor insertion port 110a of the motor case 110 opens so as to face the gear installation space 102, and as shown in FIG. 11, the motor bracket 5a is located at a position around the motor insertion port 110c using screws 5b arranged at three points. The motor 5 is fixed by being screwed. In the gear installation space 102, a motor positioning line that conforms to the contour of the motor bracket 5a is formed.

  A power supply terminal (motor terminal) 51 of the motor 5 is led to a space covered by the gear cover 103 through the motor bracket 5a (FIGS. 7 and 8), and a connection fitting 82 is provided on the terminals 80a and 80b provided on the gear cover 10. Connected through.

  In the present embodiment, the throttle sensor 30 is arranged together on one side of the side wall of the throttle body 100 together with the reduction gear mechanism 4, the default opening setting mechanism (default lever 6, default spring 8, stopper 11, etc.). .

  The throttle sensor 30 detects the throttle valve opening (throttle position). In this embodiment, as shown in FIGS. 3 to 5, all throttle sensor elements except the throttle sensor type, that is, the throttle valve shaft are used. Is housed inside the gear cover 103 so as to be covered by the sensor cover 31.

One end 3a of the throttle valve shaft 3 extends so as to reach the position of the rotor (rotor) 32 of the throttle sensor 30 when the gear cover 103 is attached. When the gear cover 103 is attached to the throttle body 100 , the one end 3a of the throttle valve shaft 3 The rotor shaft hole 37 exposed in the cover 31 is set so as to fit naturally.

  Here, the configuration of the throttle sensor 30 and the gear cover 103 will be described with reference to FIGS. 18 to 26 in addition to FIGS.

  18 is a perspective view of the inside of the gear cover 103, FIG. 19 is an exploded perspective view of the throttle sensor 30 built in the gear cover 103, FIG. 20 is an exploded perspective view showing the viewing direction changed, and FIG. FIG. 22 is a plan view of the gear cover 103 as viewed from the inside, FIG. 23 is a plan view of the terminal fixing plate 103-2 that is a part of the gear cover 103, and FIG. 24 is a terminal fixing plate. FIG. 25 is a perspective view of 103-2, FIG. 25 is a perspective view showing a different viewing direction, and FIG. 26 is a perspective view of a terminal (wiring).

  A gear cover 103 that covers the installation space 102 of the reduction gear mechanism 4 is molded from a synthetic resin, and is integrally formed with a connector case 103b for connection to an external power source and a signal line.

  The throttle sensor 30 employs a potentiometer system. As shown in the exploded perspective views of FIGS. 19 and 20, a substrate 35 having resistors 39 and 39 'formed on one surface and having terminals 61 and 61'. And the rotor 32 with the sliding brush 33 in contact with the resistance wire 39 and the sliding brush 33 ′ in contact with the resistance wire 39 ′, and a metal wave washer that repeats wavy irregularities in the circumferential direction (thereby And a sensor cover (plate) 31 made of synthetic resin. In this embodiment, the resistor 39 and the sliding brush 33 constitute one throttle sensor, and the resistor 39 'and the sliding brush 33' constitute another throttle sensor. Even if a failure occurs, the other throttle sensor can perform an alternative function. As shown in FIG. 20, the sliding brushes 33 and 33 'are fitted into the small protrusions 32b on the rotor 32 and attached to the rotor 32 by crushing the small protrusions 32b with heat.

  The substrate 35 is bonded to the inner bottom 103 a ′ of the throttle sensor housing space (circular recess) 103 a formed on the inner surface of the gear cover 103. A rotor shaft support hole 103c is formed in the center of the inner bottom 103a ′ of the throttle sensor housing space to be engaged with a protrusion (rotary shaft) 32a provided at the center of the rotor 32. The protrusion 32a of the rotor 32 is formed at the center of the substrate 35. And is fitted into the rotor shaft support hole 103c through the washer 200.

  The sensor cover 31 is provided with a plurality of mounting holes 31c on the periphery thereof. After the substrate 35, the rotor 32, and the wave washer (rotor pressing spring) 34 are accommodated in the sensor accommodating space 103a, the attachment hole 31c is provided on the gear cover 103 side. The small protrusion 103g (FIGS. 18 and 21) is fitted and the small protrusion 103g is attached by being crushed by heat.

  The wave washer 34 is sandwiched between the rotor 32 and the sensor cover 31 and is compressed and deformed by this squeezing force to support the rotor 32 without rattling and to improve vibration resistance. A shaft hole (boss hole) 37 for fitting one end 3a of the throttle valve shaft 3 is formed on the surface of the rotor 32 opposite to the protrusion 32a. The one end 3a of the throttle valve shaft 3 is formed so that two opposing surfaces are flat, while the rotor-side shaft hole 37 fitted into the throttle valve shaft one end 3a has a cross-sectional shape of the throttle valve shaft one end 3a. Approximately facing two surfaces have flat surfaces, and the rotor 32 can be rotated together with the throttle valve shaft 3.

On the inner wall of the shaft hole 37 of the rotor 32, two grooves 36 for mounting two bent springs (metal fittings) 38 are formed in a 90 ° arrangement (FIG. 21). The elastic piece of the leaf spring 38 faces the shaft hole 37 from the groove 36, and the shaft end portion 3a of the throttle valve shaft 3 elastically deforms the leaf spring 38 (hereinafter also referred to as a fitting spring) into the shaft hole 37. You can push it in. In this way, the rotor 32 can be mounted on the throttle valve shaft 3 without rattling.
As shown in FIG. 27, the spring force of the fitting spring 38 acting on the throttle valve shaft 3 is F1, the spring force of the rotor pressing spring (wave washer) 34 is F2, and the spring force F1 of the fitting spring 38 is the throttle valve. When the value obtained by multiplying the friction coefficient σ1 between the shaft 3 and the shaft hole 37 is F3 (F3 = F1 × σ1), the loads of F1 and F2 are set so as to satisfy the relationship of F2> F3. Further, as shown in FIG. 28, the rotational torque required for the rotor 32 is F4 (F4 = spring force F2 of the rotor pressing spring 34 × friction force σ2 during rotation of the rotor), and rotation that opposes the spring force F1 of the fitting spring 38. When the torque is F5, the loads of F1 and F2 are set so as to satisfy the relationship of F5> F4.

  Due to the relationship of F2> F3, the rotor 32 is always held at a constant position with respect to the vibration in the axial direction of the throttle valve shaft 3, and the fluctuation (chattering) of the throttle sensor output is reduced.

  Further, due to the relationship of F5> F4, the followability of the rotation angle of the rotor 32 with respect to the rotation angle of the throttle valve shaft 3 can be improved, and the response of the sensor output can be improved.

  One end 3b of the throttle valve shaft 3 opposite to the throttle sensor 30 side also protrudes from the side wall of the throttle body 100 as shown in FIGS. 3 to 5, and has a flat surface at the protruding portion. An inspection jig for applying a rotational torque from the outside can be engaged through the plane as required.

  Next, the electrical wiring structure applied to the gear cover 103 will be described with reference to FIGS.

  In the gear cover 103, a plurality of conductors 80 (for example, a total of six conductors 81) serving as sensor output lines and a power output conductor 80 are embedded in a resin mold. Here, the wiring structure of the conductors 80 and 81 will be described with reference to FIG. 26 except for the resin mold.

  The two conductors 80 for power supply have connector terminals 80a ′ and 80b ′ at one end for connecting to an external power supply, and connection terminals 80a and 80b connected to the motor terminal 51 of the electric actuator 5 at the other end. The resin molding is performed except for these terminals. There are a total of four conductors 81 serving as sensor output lines, of which two ends 81a and 81b are connected to the resistance terminal 61 shown in FIG. 19, and the remaining two ends 81c and 81d are resistance terminals. 61 'is connected. The other ends 81a ′, 81b ′, 81c ′, 81d ′ serve as sensor output connector terminals. Most of the conductors 80 and 81 excluding these terminals are embedded by a resin mold (gear cover) 103.

  As shown in FIGS. 18-22, the power terminals 80a, 80b and the sensor signal output terminals 81a, 81b, 81c, 81d protrude perpendicularly to the inner surface of the gear cover 103, and the power terminals 80a, 80b. Is provided opposite to the motor terminal 51 on the throttle body 100 side (see FIGS. 3 and 4), and the sensor signal output terminals 81a to 81d are disposed on the inner bottom 103a ′ of the throttle sensor housing 103a. 35 corresponding to the 35 resistance terminals 61 and 61 '(see FIG. 19).

The power terminals 80a and 80b are connected to the motor terminal 51 via a joint-type connection fitting 82. By fixing the substrate 35 at a predetermined position 103a ′ in the gear cover 103, the pair of resistance terminals 61 of the substrate 35 overlap the sensor signal output terminals 81a and 81b, and the other pair of resistance terminals 61 ′ is the sensor signal output terminals 81c and 81d. The overlapping terminals are welded together (for example, projection welding). Sensor signals from the sensor signal output terminals 81a and 81b and sensor signals from the sensor signal output terminals 81c and 81d are sent to the connector terminals 81a ', 81b' and 81c ', 81d' for external connection through the conductors 81. Led.
In the connector 103b, a total of six connector terminals 80a ', 80b' for power supply and connector terminals 81a ', 81b', 81c ', 81d' for sensor signal output are arranged in three rows vertically. Has been.

  As shown in FIG. 21, a part of the gear cover 103 has a two-layer structure of an inner layer 103-2 and an outer layer 103-1, and the inner layer 103-2 has a plate shape molded in advance by itself and is molded by molding. The conductors 80 and 81 are embedded except for the terminals, and the plate 103-2 constituting the inner layer is integrated with the gear cover main body 103-1 serving as the outer layer by molding the gear cover main body.

  That is, as shown in FIGS. 23 to 25, the plate 103-2 is molded in advance together with the conductors 80 and 81, and then the plate 103-2 is set in a gear cover molding die and the gear cover main body 103 is set. -1 is molded, and the plate 103-2 is thus positioned as an inner layer near the center of the gear cover 103.

  The reason why the conductors 80 and 81 with terminals are fixed by molding the plate 103-2 before the gear cover 103 is molded is that the conductors 80 and 81 are embedded in the gear cover 103 from the beginning when the gear cover 103 is molded. Then, since the structure of the gear cover is complicated, it is difficult to hold the conductors 80 and 81 in the mold frame from the beginning because there are obstacles, so the conductors 80 and 81 move during molding, This is because it is difficult to embed the conductors 80 and 81 in an appropriate state. That is, when the conductors 80 and 81 are embedded in advance when the terminal fixing plate 103-2 is molded, the conductor portion exposed from the plate 103-2 can be easily pressed down, so that the terminal is in an appropriate state. The attached conductors 80 and 81 can be embedded integrally with the terminal fixing plate 103-2, and if this plate 103-2 is set in a molding frame of the gear cover main body 103-1, the conductor with terminals is already provided. Since 80 and 81 are fixed, the layout of the conductors 80 and 81 can be prevented from being out of order.

The gear cover 103 is attached to the throttle body by tightening a screw 150 through a screw hole 152 provided in the cover 103 and a screw hole 151 provided in a corner of the frame 104. Further, the gear cover 103 needs to be attached to the throttle body 100 with the directionality specified. For this reason, the projections 170, 171, 172 provided on the inner surface of the gear cover 103 are positioned on the positioning surfaces 160, 161, 161 provided on the throttle body 100 side. The gear cover and the throttle body can be fitted only when conforming to 162, so that the direction of the gear cover can be installed without making a mistake.
The effects of the above embodiments are summarized as follows.

  (1) Conventionally, the installation space 102 of the reduction gear mechanism 4 is covered by a gear case provided on the side wall of the throttle body and a gear cover that covers the gear case, but in this example, a gear cover is used instead of the conventional gear case. 103 covers most of the installation space 102. Accordingly, the throttle body itself does not need to be integrally molded with a gear case having a relatively large volume as in the prior art, and the volume is increased on the side of the lightweight synthetic resin gear cover. The body shape can be reduced in size and weight.

  (2) Since the default stopper 11 and the fully closed stopper 12 are arranged in the throttle body 100 so that the positions can be adjusted from the same direction, the screw holes of these stoppers (screws) can be drilled from the same direction. In addition, it becomes possible to adjust the position of the stopper from the same direction at a close position, and the adjustment work can be simplified.

  (3) Even if the gear cover mounting frame 104 is reduced in height in order to reduce the shape of the throttle body 100 and reduce the weight, the protrusion 102a for mounting the fully closed stopper 12 is provided beyond the height of the frame 104. Since the full-close stopper 12 is arranged on the protrusion 102a in accordance with the mounting height of the throttle gear (final gear) 43, the throttle gear 43 can be received by the full-close stopper 12.

  (4) Since the return spring 7 and the default spring 8 can be arranged by utilizing the empty space that inevitably occurs around the bosses 101, 43c, 6f, the space can be rationalized, and the throttle gear 43 Since the bosses 43c provided on the boss 43c are formed so as to be concentrated on one side, the amount of bosses protruding from one side of the throttle gear 43 (boss shaft length) is the double-sided boss type (the bosses protrude on both sides of the final gear). ) Can be secured longer than the amount of protrusion on one side. Therefore, it is possible to secure the installation space for the default opening degree setting mechanism without waste while maintaining the downsizing of the apparatus.

  (5) Since the default lever 6 and the throttle gear 43 also serve as a spring receiver for the default spring 8, a collar member dedicated to the spring receiver can be omitted, and the parts can be simplified.

  Since the default lever 6 has at least a portion constituting the boss 6f and a portion receiving the default spring 8 formed of synthetic resin, the default spring 8 is twisted by the relative rotation of the default lever 6 and the throttle gear 43. In addition, the friction between the default spring 8 and the spring receiving portion, the boss portion, etc. of the default lever 6 in contact with the default spring 8 is reduced to reduce the load on the motor. Further, since the coating for reducing the friction coefficient is applied to the surfaces of the return spring and the default spring, the friction can be reduced even if the metallic throttle gear 43, the throttle body 100, etc. receive one end of these springs.

  (6) By making the compressive stress F of the spring having the larger coil diameter of the return spring 7 and the default spring 8 larger than the compressive stress f of the spring having the smaller coil diameter, the default lever 6 is moved closer to the outer diameter. Since the position is pressed in a stable state in one direction, the default lever fitted to the throttle valve shaft 3 can be maintained in a stable and appropriate state, and the accuracy of the default opening can be prevented from being distorted.

  (7) Since the throttle gear (final gear) 43 also serves as a movable side defining element that defines the mechanical fully closed position, and this defining element is fixed to the throttle valve shaft 3 by press fitting, so the throttle gear Even when 43 is in contact with the fully closed stopper 12 and an impact is applied, the positional relationship of the throttle gear 43 with respect to the throttle valve shaft 3 can always be kept constant. Therefore, there is no deviation in the opening degree of control of the throttle valve determined based on the mechanical fully closed position, which contributes to maintaining control accuracy.

  (8) By flattening the motor housing and thus the motor case 110, it is possible to contribute to the reduction in size and weight of the throttle body 100, and one of the flat inner surfaces 110b of the motor case 110 is an idle for controlling the throttle valve 2. Since the outer wall surface of the intake passage on the downstream side of the opening position is configured, even when the intake air flow rate is small as in idle rotation, it occurs downstream immediately after passing through the throttle valve 3 during idle rotation. The cooling effect by adiabatic expansion of the intake air flow rate is most efficiently received. Therefore, the cooling inside the motor case, and thus the heat dissipation of the motor housing, can be enhanced, contributing to the motor cooling effect.

  (9) Further, one inner surface 110b of the opposed flat inner surfaces of the motor case 110 is formed so as to be recessed from the surrounding intake passage outer wall surface, so that the intake air in the motor case 110 is shown in FIG. By reducing the wall thickness adjacent to the passage 1 and bringing the motor case inner surface 70b closer to the intake passage 1 side, the cooling action by the intake air passing through the intake passage is efficiently received.

  (10) The throttle sensor 30 can be assembled by assembling the set of parts only on the gear cover 103 side, and the assembling work becomes very simple. If this gear cover 103 is attached to the side wall of the throttle body 100, the tip of the throttle valve shaft 3 naturally engages with the shaft hole of the rotor 32 of the throttle sensor 30, so that the throttle valve shaft 3 and the throttle sensor 30 can be easily engaged. Can be done with one touch. Further, since the throttle sensor 30 is covered with the sensor cover 31 inside the gear cover, the throttle sensor 30 exhibits a dustproof function, and even if the gear cover 103 is removed or attached, dust or parts wear powder or the like can enter. Prevent and increase sensor reliability.

  (11) One end of the throttle valve shaft 3 is fitted into the shaft hole 37 of the rotor 32 with the elastic deformation of the spring 38 provided in the shaft hole, and the rotor 32 is interposed between the rotor and the sensor cover 31. By being pressed by the rotor pressing spring 34, the rotor is always held at a fixed position with respect to the vibration of the throttle valve shaft, and fluctuation in the throttle sensor output (chattering) is reduced. Further, the followability of the rotor rotation angle with respect to the rotation angle of the throttle valve shaft can be improved, and the response of the sensor output can be improved.

  (12) An inspection jig can be engaged with the end 3b of the throttle valve shaft 3 opposite to the throttle sensor, so that rotational torque can be applied from the outside, whereby the output characteristics of the throttle sensor can be examined. .

  (13) Connector terminals 80a 'and 80b' for connecting to an external power source on the gear cover 103, conductors 80 of the connecting terminals 80a and 80b for connecting to the motor terminal 51, sensor output terminals 81a to 81d, and connector terminals thereof Since the conductors 81a 'to 81d' are embedded, the labor for wiring these terminals can be saved. In addition, if the gear cover 103 is attached to the throttle body 100, the gear cover side connection terminals 80a and 80b that communicate with the external power supply through the joint type fitting 82 inside the gear and the motor terminal 51 on the throttle body 100 side can be easily connected. can do.

(14) The terminal fixing plate 103-2, which is a part of the gear cover 103, is formed in advance, and the conductors 80 and 81 are embedded when the plate 103-2 is resin-molded, so that the gear cover 103 is arranged in the conductors 80 and 81 arrangement. Resin molding can be performed without causing a deviation.
[Embodiment 1]
In a throttle device that opens and closes a throttle valve that controls an intake air flow rate of an internal combustion engine by an electric actuator,
The motor used for the electric actuator has two flat opposing surfaces formed on the yoke constituting the motor housing, and the motor case housing the motor has a flat opposing inner surface that matches the shape of the motor housing. And is arranged on the side wall of the throttle body so as to cross a line orthogonal to the throttle valve shaft, and all or most of one of the opposed flat inner surfaces of the motor case is idle for controlling the throttle valve. 2. A throttle device for an internal combustion engine, comprising an outer wall surface of an intake passage located downstream of an opening position.
Embodiment 2
All or most of one of the opposing flat inner surfaces of the motor case constitutes the outer wall surface of the intake passage on the downstream side of the electrical fully closed position in the control of the throttle valve. A throttle device for an internal combustion engine according to the first embodiment.
[Embodiment 3]
In a throttle device that opens and closes a throttle valve that controls an intake air flow rate of an internal combustion engine by an electric actuator,
The motor used for the electric actuator has two flat opposing surfaces formed on the yoke constituting the motor housing, and the motor case housing the motor has a flat opposing inner surface that matches the shape of the motor housing. And is arranged on the side wall of the throttle body so as to cross a line perpendicular to the throttle valve shaft, and one of the opposed flat inner surfaces of the motor case is formed so as to be recessed from the outer intake passage outer wall surface. A throttle device for an internal combustion engine.
Furthermore, specific features of this embodiment are listed below.

  A first feature is a throttle device that opens and closes a throttle valve that controls an intake air flow rate of an internal combustion engine by an electric actuator, and transmits the power of the electric actuator to a throttle valve shaft on one surface of a side wall of the throttle body. An installation space for the reduction gear mechanism and a frame for mounting the gear cover formed so as to border the installation space for the reduction gear mechanism are formed, and the height of the frame is attached to one end of the throttle valve shaft. It is characterized in that the height is lowered to be lower than the height, and a gear cover that covers the installation space of the reduction gear mechanism is attached to the frame.

  According to the above configuration, the gear cover covers most of the installation space in place of the gear case and gear cover provided on the side wall of the conventional throttle body. The gear cover serves as a gear case. Therefore, the throttle body itself does not need to be integrally molded with a gear case having a relatively large volume as in the prior art, and the volume is increased on the side of the gear cover made of synthetic resin. The shape can be reduced in size and weight.

  The second feature is a throttle device that opens and closes a throttle valve that controls the intake air flow rate of the internal combustion engine by an electric actuator, and the opening degree of the throttle valve is larger than the fully closed position when the electric actuator is not energized. In a throttle device for an internal combustion engine having a default opening degree setting mechanism that maintains the opening degree (default opening degree) of
A stopper for prescribing the default opening and a stopper for prescribing the mechanically closed position of the throttle valve are configured by adjusting screws, and these stoppers are arranged side by side so that the position can be adjusted from the same direction. It is characterized by being.

  According to the above configuration, the default opening and the mechanical fully closed position of the throttle valve can be arbitrarily adjusted. Moreover, the adjustment screw of the default opening stopper (default stopper) and the adjustment screw of the fully closed stopper are arranged side by side in the same direction on the throttle body so that the screw holes of those stoppers (screws) can be aligned from the same direction. It is possible to drill, and the position adjustment of the stopper can be performed from the same direction at a close position, and the adjustment work can be simplified.

  A third feature is an application of the first and second inventions, wherein the fully closed stopper receives a reduction gear (final gear) fixed to the throttle valve shaft, defines a mechanical fully closed position, and is a default stopper. Is an engagement element for setting a default opening (this engagement element is freely fitted to the throttle valve shaft so as to be able to rotate on the shaft, and is engaged with the final stage gear via a spring. In a throttle device for an internal combustion engine that accepts and defines a default opening,
On one side of the throttle body side wall, there is a reduction gear installation space for transmitting the power of the electric actuator to the throttle valve shaft, and a gear cover mounting frame formed so as to border the periphery of the reduction gear installation space. The height of the frame is lowered so as to be lower than the mounting height of the final gear, and the protrusion for mounting the fully closed stopper at the position covered by the gear cover has the above-mentioned height. The fully closed stopper is disposed on the protrusion according to the mounting height of the final gear of the reduction gear, while the default stopper is for setting a default opening at a position lower than the frame. It is characterized by being arranged side by side with the fully closed stopper in accordance with the position of the engaging element (default lever).

  According to the above configuration, the installation space for the reduction gear mechanism is covered by the gear cover as in the first aspect of the invention, and the metal throttle body can be made smaller and lighter accordingly. Become.

  Further, since the final gear of the reduction gear protrudes from the gear cover mounting frame on the side wall of the throttle body, the final gear cannot be received even if a fully closed stopper is provided on this frame. Therefore, in the present invention, a protrusion for attaching the fully closed stopper for receiving the final stage gear is set, and this protrusion is provided beyond the height of the frame, and the fully closed stopper is attached to the protrusion at the mounting height of the final stage gear. Arranged according to the size.

  In this way, the final gear can be received by the fully closed stopper even if the gear cover mounting frame is reduced in height.

  A fourth feature is that in the throttle device for an internal combustion engine having the default opening setting mechanism, one end of the throttle valve shaft protrudes from the bearing boss on the side wall of the throttle body, and the power of the electric actuator is transmitted to one end of the throttle valve shaft. The final stage gear of the reduction gear is fixed, and the engagement element (default lever) of the default opening setting mechanism that can be engaged with the final stage gear between the final stage gear and the bearing boss is a throttle valve shaft. To rotate relative to the
A return spring that urges the throttle valve in the closing direction is arranged around the bearing boss, and one end of the return spring is locked to the default lever, and between the default lever and the final gear. Is arranged with a spring (default spring) for pulling the default lever and the last gear in a direction to engage with each other.
The final stage gear is formed with a throttle valve shaft insertion boss only on the side (one side) receiving the default spring, while the default lever is also inserted into the final stage gear so as to face the final stage gear boss. A common boss is formed, and the default spring is mounted around both bosses.

  According to the above configuration, the return spring and the default spring can be arranged by utilizing the empty space that inevitably arises around each boss, so that the space can be rationalized and the final gear of the reduction gear can be reduced. Since all the bosses are concentrated and formed on one side, the projection of the boss protruding from one side of the final gear (boss shaft length) is one side of the double-sided boss (the type in which the boss projects on both sides of the final gear). It can be secured longer than the protruding amount of the boss on the side. Therefore, it is possible to ensure a space for attaching the spring of the default opening setting mechanism without waste while maintaining the downsizing of the apparatus.

  A fifth feature of the throttle device for an internal combustion engine having the default opening degree setting mechanism is that a final gear of a reduction gear that transmits power of the electric actuator is fixed to one end of a throttle valve shaft, An engagement element (default lever) of the default opening setting mechanism is fitted so as to be rotatable relative to the throttle valve shaft, and the default lever and the final gear are placed between the default lever and the final gear. A spring for setting a default opening degree (default spring) that is pulled in a direction to engage with each other is disposed, and the default spring has a spring receiving structure that directly receives the default lever and the final gear. To do.

  According to the above configuration, since the default lever and the final gear of the reduction gear also serve as the spring receiver for the default spring, the parts can be simplified.

  As an application example, a default lever is proposed in which at least a portion constituting the boss and a portion for receiving the default spring are formed of a synthetic resin.

  In this case, since the synthetic resin has a smaller coefficient of friction than the metal member, even if the default spring is twisted by the relative rotation of the default lever and the final gear, the member that contacts the default spring ( The friction between the default lever and the spring receiving part and boss part) is reduced to reduce the load on the motor. Therefore, the movement of the throttle valve by the motor can be made smooth, and the motor power consumption during operation can be reduced.

  Furthermore, if the surface of the return spring and the default spring is coated to reduce the coefficient of friction, the friction with the counterpart member that occurs during the twisting operation of these springs can be further reduced.

  A sixth feature is a throttle device that opens and closes a throttle valve that controls an intake air flow rate of an internal combustion engine by an electric actuator.
The motor used for the electric actuator has two flat opposing surfaces formed on the yoke constituting the motor housing, and the motor case housing the motor has a flat opposing inner surface that matches the shape of the motor housing. And is arranged on the side wall of the throttle body so as to cross a line orthogonal to the throttle valve shaft, and all or most of one of the opposed flat inner surfaces of the motor case is idle for controlling the throttle valve. It is characterized in that the outer wall surface of the intake passage on the downstream side of the opening position (for example, the downstream side of the electrical fully closed position in the control of the throttle valve) is configured.

  According to the above configuration, it is possible to contribute to the reduction in size and weight of the throttle body by flattening the motor housing and thus the motor case, and one of the flat inner surfaces of the motor case is an idle opening position for controlling the throttle valve. Since the outer wall surface of the intake passage on the downstream side is configured, even when the intake air flow rate is small, such as during idle rotation, the motor case is located downstream immediately after passing the throttle valve during idle rotation. The cooling effect by the adiabatic expansion of the generated intake air flow rate is most efficiently received. Therefore, the cooling inside the motor case, and thus the heat dissipation of the motor housing, can be enhanced, contributing to the motor cooling effect.

  A seventh feature is that, similarly to the above, the motor case that houses the motor has a flat opposing inner surface that matches the shape of the motor housing, and is arranged on the side wall of the throttle body so as to intersect a line perpendicular to the throttle valve shaft. In addition, one of the opposing flat inner surfaces of the motor case is formed so as to be recessed from the outer wall surface of the surrounding intake passage.

  According to the above configuration, the wall of the motor case adjacent to the intake passage is thinned so that the inner surface of the motor case is closer to the intake passage side, thereby efficiently receiving the cooling action by the intake air passing through the intake passage. It becomes possible.

  As described above, in the present invention, there are various effects in each invention. To summarize, in an electronically controlled throttle device including an electric actuator, a gear mechanism, a default opening setting mechanism, etc. It is possible to achieve effects such as weight reduction, rationalization of production and adjustment work, and operational stability and accuracy.

The perspective view which shows typically the power transmission and default mechanism of the throttle valve of the electronically controlled throttle apparatus in one Example of this invention. FIG. 2 is a principle explanatory view equivalently showing the operation of the electronically controlled throttle device of FIG. 1. FIG. 3 is a cross-sectional view of the electronically controlled throttle device according to the embodiment perpendicular to the axial direction of the intake passage. The figure which removes the gear cover with a throttle sensor and shows the said throttle apparatus in the same cross-sectional position as FIG. FIG. 4 is a cross-sectional view of the throttle device of FIG. 3 in the axial direction of the intake passage. The perspective view of the said throttle apparatus. The perspective view which removes a gear cover and shows the throttle device. The perspective view which changed the angle of the said throttle device. The perspective view which changed the angle of the said throttle device. The top view of the said throttle apparatus. The figure which removed the gear installation part of the said throttle apparatus, and looked from the outside. It is explanatory drawing which shows the attachment state of a fully closed stopper and a default stopper, The (a) is a figure which shows partially FIG. 11 seeing from A direction, (b) is the BB sectional drawing of (a). The figure which shows the positional relationship of the intake passage of the said throttle apparatus, and a motor case by BB line of FIG. Sectional drawing which removed the motor from the motor case of FIG. The disassembled perspective view of the throttle device which concerns on the said Example. The disassembled perspective view which expands and shows a part of FIG. FIG. 17 is an exploded perspective view showing the part of FIG. The perspective view which looked at the inner side of the gear cover used for the said Example. The disassembled perspective view of the throttle sensor built in the said gear cover. The disassembled perspective view which changes and shows the direction which looks at the throttle sensor of FIG. The longitudinal cross-sectional view of the said gear cover. The top view which looked at the said gear cover from the inner side. The top view of the plate for terminal fixation which is a part of said gear cover. The perspective view of the said plate for terminal fixation. The perspective view which changes and shows the direction which sees the said plate for terminal fixation. The perspective view of the terminal (wiring) fixed by the resin mold of the said fixing plate. Operation | movement explanatory drawing of the throttle sensor used for the said Example. It is operation | movement explanatory drawing of the throttle sensor used for the said Example.

2 ... throttle valve, 3 ... throttle valve shaft, 5 ... electric actuator (motor), 6 ... engagement element (default lever) for setting the default opening, 7 ... return spring, 8 ... default spring.

Claims (4)

A throttle device that opens and closes a throttle valve that controls the intake air flow rate of an internal combustion engine by an electric actuator, and that opens the throttle valve at a default opening larger than a fully closed position when the electric actuator is not energized. In a throttle device for an internal combustion engine having a degree setting mechanism,
An engagement element for setting a default opening is fitted to one end of the throttle valve shaft so as to be rotatable relative to the throttle valve shaft,
The axial end of the throttle valve, the final stage gear of the reduction gear for transmitting the power of the throttle valve shaft of the electric actuator is mounted, the return spring between the final-stage gear and the throttle body side wall one side, the An engagement element for setting the default opening and a spring for setting the default opening are interposed.
So as to sandwich the engagement element, the default opening setting for biasing said return spring for urging the spring force in the direction closing the throttle valve, the spring force of the default opening side as viewed from the fully closed position of the throttle valve These springs are formed of coiled twisted springs, and both surfaces of the engagement element serve as spring receivers for the return spring and the default opening setting spring. One end of these springs is locked, and both springs have different coil diameters and are compressed in the axial direction, and the compression stress F of the spring with the larger coil diameter is applied to the spring with the smaller coil diameter. A throttle device for an internal combustion engine, wherein the throttle device is larger than the compressive stress f.   The final stage gear is attached to one end of the throttle valve by tightening a nut or press-fitting, and the return spring, the engagement element for setting the default opening, The return spring and the default opening degree setting for the compression stress F> f by a tightening force of a nut for tightening the final stage gear or a pressure input for press-fitting the final stage gear through a spring. The throttle device for an internal combustion engine according to claim 1, wherein the spring is compressed in the axial direction. 3. The internal combustion engine according to claim 1, wherein the final stage gear is configured to be able to contact a stopper that defines a mechanical fully closed position of the throttle valve by driving the electric actuator. Throttle device. Throttle device for an internal combustion engine according to any one of claims 1乃optimum 3 wherein the engaging element is characterized in that are configured to abut the default stopper provided on said default position.

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