JP2013104390A - Throttle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve unfreezing performance between a throttle valve and a bore inner wall.SOLUTION: In this throttle device, a throttle shaft 4 is rotated by an electric motor or the like, thereby changing the opening of a bore 11 by the throttle valve 5 to adjust the intake air flow rate of the bore 11. The throttle shaft 4 is rotatively supported by a pair of sliding bearings 21A (21B) provided correspondingly at both the ends of the throttle shaft. Both the bearings 21A (21B) are arranged in a throttle body 2 (12) so that the throttle shaft 4 is located adjacently to the downstream end 11b of the bore 11. When the throttle valve 5 is made in a closed state where the bore 11 is substantially closed, the throttle valve 5 is arranged at a predetermined closing angle θ1 with respect to the radial direction of the bore 11, and one end 5a of the throttle valve 5 is arranged adjacently to the downstream end 11b of the bore 11. When the throttle valve 5 starts to open the bore 11, the one end 5a of the throttle valve 5 immediately protrudes from the bore 11.

Description

  The present invention relates to a throttle device that is provided in an intake passage of an engine and used for adjusting an intake air amount.

  Conventionally, as this type of technology, for example, engine throttle devices described in Patent Documents 1 and 2 below are known. Each of the devices described in Patent Documents 1 and 2 includes a throttle body and a throttle valve that is rotatably provided through a throttle shaft in a bore of the throttle body, and rotates the throttle valve by the throttle shaft. By adjusting the opening of the bore, the amount of air taken into the engine (intake amount) is adjusted.

  Here, when the engine is stopped when cold, the closed throttle valve may freeze with the inner wall of the bore. For this reason, it is necessary to prevent freezing during cold weather or to quickly release freezing when the engine is started. Therefore, in the apparatus described in Patent Document 1, the inner wall of the bore in which the throttle valve is disposed is a cylindrical core formed of a metal heat generating material that generates heat when electricity is applied. The cylindrical core is heated by passing an electric current through an electric circuit when it is cold. Due to the heat generated by the cylindrical core, moisture adhering to the inner wall of the bore and moisture in the bore are evaporated to prevent freezing. Further, when the engine is cold started, the freezing can be released by generating heat in the cylindrical core.

  On the other hand, in the apparatus described in Patent Document 2 below, both end portions of the throttle shaft are rotatably supported by ball bearings at the bearing holding portions of the throttle body. A throttle gear is provided at one end of the throttle shaft, and this throttle gear is drivingly connected to a motor gear provided on the output shaft of the motor via an intermediate gear. Then, by driving the electric motor by energization, the throttle shaft is rotated via the motor gear, the intermediate gear, and the throttle gear, and the throttle valve is opened and closed. Here, since the ball bearing has a required outer diameter centering on the throttle shaft, a certain amount of space is required for the bearing holding portion and the bore of the throttle body. For example, as shown in a schematic cross-sectional view in FIG. 17, the axial length of the bore 82 of the throttle pipe 81 formed in the throttle body should be long enough to include at least the outer diameter of the ball bearing 83. Must be secured. In FIG. 17, the left side of the throttle pipe 81 indicates the upstream side with respect to the air flow, and the right side indicates the downstream side. Then, a length R1 that is sufficient to secure at least the outer diameter of the ball bearing 83 around the throttle shaft 84 is required on the downstream side of the bore 82 around the throttle shaft 84. In FIG. 17, the throttle valve 85 provided on the throttle shaft 84 is held at a predetermined closing degree close to a fully closed state.

Japanese Patent Laid-Open No. 2003-13754 JP 2003-83095 A

  However, in the apparatus described in Patent Document 1, since the cylindrical core made of a heat generating material and an electric circuit are provided in order to release the freezing of the throttle valve, the number of parts is increased by that amount, and the number of steps for assembling the parts is increased. However, there is concern about an increase in manufacturing costs.

  On the other hand, in the apparatus described in Patent Document 2, when the engine is cold started, the throttle valve 85 and the inner wall of the bore 82 may freeze as shown in FIG. That is, there is a possibility that ice J1 is formed between the lower end portion of the throttle valve 85 and the inner wall of the bore 82. In order to release this icing, it can be considered that the electric motor is operated by energization to rotate the throttle valve 85 to release the icing. However, since the dimension of the length R1 is required on the downstream side of the bore 82 by the size of the ball bearing 83, the ice J1 formed between the throttle valve 85 and the bore 82 as shown in FIG. The contact area S1 with respect to the inner wall of the bore 82 tends to increase. For this reason, the throttle valve 85 must be rotated with a large torque by the electric motor in order to cancel the freezing as much as the contact area S1 is large, and the freezing property is not good. In this respect, in order to ensure a good deicing property, an electric motor having a large output torque is used, energization energy to the electric motor is increased, or a heating member is provided on the throttle body as in the device of Patent Document 1. Must be established.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a throttle device that can improve the release of icing between the throttle valve and the inner wall of the bore.

  In order to achieve the above object, an invention according to claim 1 includes a throttle body having a bore, a throttle shaft disposed so as to cross the bore and rotatably supported by a throttle body via a bearing, A throttle valve provided on the throttle shaft in the bore and opening and closing the bore by rotation of the throttle shaft, a gear mechanism including a throttle gear provided on the throttle shaft, and an electric motor drivingly connected to the gear mechanism A throttle device that adjusts the amount of air flowing through the bore by changing the opening of the bore by the throttle valve by rotating the throttle shaft via a gear mechanism by an electric motor, the throttle shaft having a first end portion And the second end, and the bearing is provided corresponding to the vicinity of the first end and the second end, The bearing is composed of a slide bearing formed of a plate material, the bore has an upstream end and a downstream end with respect to the air flow in the axial direction, and both bearings so that the throttle shaft is adjacent to the downstream end of the bore Is disposed on the throttle body, and when the throttle valve is in a closed state that substantially closes the bore, the throttle valve is disposed at a predetermined closing angle with respect to the radial direction of the bore, and one end of the throttle valve is located downstream of the bore. It is arranged adjacent to the side end, and it is intended that one end of the throttle valve protrudes from the bore when the throttle valve starts to open the bore.

  According to the configuration of the above invention, the pair of bearings that rotatably support the first end portion and the second end portion of the throttle shaft on the throttle body are constituted by the slide bearing formed of the plate material. The outer diameter is relatively small. And since both bearings which consist of a sliding bearing are arrange | positioned at a throttle body so that a throttle shaft may adjoin the downstream downstream end of a bore, the dimension from the center of a throttle shaft to the downstream downstream end of a bore becomes comparatively small. On the other hand, when the throttle valve is closed, the throttle valve is disposed at a predetermined closing angle, and one end of the throttle valve is disposed adjacent to the downstream end of the bore. The arrangement of the throttle valve is such that one end of the throttle valve protrudes from the bore when the throttle valve rotates and begins to open the bore. Accordingly, when the one end of the throttle valve and the inner wall of the bore are frozen, the contact area between the throttle valve and the inner wall of the bore and the ice is relatively small.

In order to achieve the above object, the invention according to claim 2 further comprises a throttle sensor for detecting the opening of the bore by the throttle valve in the invention according to claim 1,
A throttle gear is fixed to the second end of the throttle shaft, a throttle sensor is provided adjacent to the throttle gear, and the throttle sensor is disposed between the pair of permanent magnets and the pair of permanent magnets. It is intended to include an MRE element that detects the direction of the generated magnetic field.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 1, the throttle sensor detects the direction of the opening of the bore by the throttle valve (throttle throttle) when the MRE element detects the direction of the magnetic field of the pair of permanent magnets. Opening degree) is detected. Therefore, for example, even if the magnetic field strength of the permanent magnet slightly changes due to a positional shift of the permanent magnet or a temperature change caused by a positional shift of the throttle shaft, the direction of the magnetic field of the permanent magnet is not affected. That is, even if a change occurs in the magnetic field strength of the permanent magnet, the throttle opening is detected based on the direction of the magnetic field without being affected by the change. This is suitable for the throttle device of the present invention that rotatably supports the throttle shaft by using a relatively simple bearing.

  In order to achieve the above object, the invention according to claim 3 is the invention according to claim 1 or 2, wherein the throttle body includes a throttle pipe having a bore, and a motor housing that houses an electric motor, It is intended that the motor housing is disposed with a gap with respect to the throttle pipe, and a part of the outer peripheral surface of the motor housing is disposed further downstream than the downstream end of the bore.

  According to the configuration of the invention described above, in addition to the operation of the invention according to claim 1 or 2, the motor housing is disposed with a gap in the throttle pipe, and a part of the outer peripheral surface of the motor housing is arranged at the downstream end of the bore. Since it is disposed further downstream than the motor housing, the surface area of the motor housing itself increases.

  To achieve the above object, according to a fourth aspect of the present invention, in the first or second aspect of the present invention, the throttle body includes a throttle pipe having a bore and corresponds to a downstream end of the bore. One end of a manifold pipe constituting the intake manifold of the engine is connected to the downstream end of the engine, and the inside diameter of the intake passage in the manifold pipe is larger than the inside diameter of the bore.

  According to the configuration of the above invention, in addition to the operation of the invention described in claim 1 or 2, one end of the manifold pipe is connected to the downstream end of the throttle pipe, and the inner diameter of the intake passage in the manifold pipe is bored. Since it is larger than the inner diameter, moisture in the bore easily flows into the intake passage of the manifold pipe. Further, when the throttle valve starts to open the bore, one end of the throttle valve protrudes from the bore into the intake passage of the manifold pipe having a large inner diameter, so that the air flow rate of the bore increases nonlinearly at the start of opening of the throttle valve.

  In order to achieve the above object, according to a fifth aspect of the invention, in the invention of the fourth aspect, the intake passage in the manifold pipe is gradually reduced in diameter from one end of the manifold pipe to the downstream side. The purpose.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 4, since the diameter of the intake passage of the manifold pipe is gradually reduced from one end to the downstream side, the air in the bore is started after the throttle valve starts to open. The flow rate increases slowly.

  According to the first aspect of the present invention, the throttle body can be reduced in size, and the release of icing between the throttle valve and the inner wall of the bore can be improved.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, it is possible to ensure the detection accuracy of the throttle opening for the throttle device using both bearings made of the sliding bearing.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the heat dissipation of the electric motor by the motor housing can be improved.

  According to the invention described in claim 4, in addition to the effects of the invention described in claim 1 or 2, icing between the throttle valve and the inner wall of the bore can be reduced, and the intake flow rate characteristic by the throttle device can be easily achieved. It can be arbitrarily changed, and the generation of abnormal noise due to intake at the beginning of opening of the throttle valve can be suppressed.

  According to the fifth aspect of the present invention, like the effect of the fourth aspect of the present invention, it is possible to reduce icing between the throttle valve and the inner wall of the bore, and the intake flow rate characteristic by the throttle device can be easily and arbitrarily set. This can be changed, and the generation of abnormal noise due to intake at the beginning of opening of the throttle valve can be suppressed.

The front view which concerns on 1st Embodiment and shows a throttle device. The bottom view of FIG. 1 which concerns on the embodiment and shows a throttle device. The right view of FIG. 1 which shows the throttle apparatus concerning the embodiment. FIG. 3 is a cross-sectional view taken along line AA of FIG. 2 showing the throttle device according to the embodiment. FIG. 5 is an enlarged cross-sectional view of a part of FIG. 4 for the throttle device according to the same embodiment. The right view of FIG. 1 which shows the state which concerns on the embodiment and the gear cover was removed from the throttle device. The BB sectional drawing of FIG. 1 which shows the state which concerns on the embodiment and the gear cover was removed from the throttle device. The rear view which concerns on the embodiment and shows a throttle gear with a related component. The model figure which shows the relationship between a throttle gear, a throttle body, a return spring, and an opener spring concerning the embodiment. The model figure which shows the relationship between a throttle gear, a throttle body, a return spring, and an opener spring concerning the embodiment. FIG. 3 is a cross-sectional view schematically showing a relationship among a throttle pipe, a throttle shaft, a throttle valve, and both bearings according to the same embodiment. FIG. 12 is a cross-sectional view schematically showing a state in which the throttle valve is frozen on the inner wall of the bore during the cold state according to the embodiment in the state of FIG. 11. FIG. 4 is a cross-sectional view schematically showing a state in which a manifold pipe is connected to a throttle pipe according to the embodiment. The graph which shows the characteristic of the intake air flow volume with respect to the embodiment regarding throttle opening. Sectional drawing which concerns on 2nd Embodiment and shows the state which connected the manifold pipe to the throttle pipe. The graph which shows the characteristic of the intake air flow volume with respect to the embodiment regarding throttle opening. Sectional drawing which concerns on a prior art example and shows schematically the relationship between a throttle pipe, a throttle shaft, a throttle valve, and both bearings. FIG. 18 is a cross-sectional view schematically showing a state in which the throttle valve is frozen on the inner wall of the bore when it is cold according to the conventional example.

<First Embodiment>
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment that embodies the throttle device of the present invention will be described in detail below with reference to the drawings. The throttle device according to this embodiment is provided in an intake passage of an automobile engine and is used to adjust the intake air amount of the engine.

  FIG. 1 is a front view of a throttle device 1 according to this embodiment. FIG. 2 similarly shows the throttle device 1 from the bottom view of FIG. FIG. 3 also shows the throttle device 1 in the right side view of FIG. As shown in FIGS. 1 and 2, the throttle device 1 includes a metal throttle body 2 and a resin gear cover 3.

The throttle body 2 includes a cylindrical throttle pipe 12 having a bore 11 communicating with an intake passage of the engine, a gear housing 13 that houses a gear mechanism 9 (see FIG. 4) and the like, and an electric motor 8 (see FIG. 4). 4)). The gear housing 13 extends in the vertical direction in FIG. The motor housing 14 is arranged such that the central axis L1 intersects the gear housing 13 perpendicularly. The throttle pipe 12 is arranged away from both the gear housing 13 and the motor housing 14. A flange 15 is formed at one end of the throttle pipe 12 (end on the downstream side of the air flow). A total of three bolt insertion holes 15 a are formed in the flange 15. An intake manifold manifold pipe 51 (see FIG. 13), which will be described later, is connected to the flange 15. As shown in FIG. 1, a throttle shaft 4 is provided in the throttle pipe 12 so as to cross the bore 11 in the radial direction. The throttle body 2 is formed with a pair of first boss portions 16A and second boss portions 16B that accommodate both ends of the throttle shaft 4. A throttle valve 5 fixed to the throttle shaft 4 is disposed in the bore 11.

  Here, as shown in FIG. 1, the motor housing 14 is disposed with a gap from the throttle pipe 12. Further, the central axis L1 of the motor housing 14 and the throttle shaft 4 are arranged in parallel. In FIG. 2, the throttle pipe 12 has an upstream end 12a for the air flow on the upper side of the drawing, and a downstream end 12b for the air flow on the lower side of the drawing. In FIG. 2, the upstream end 12 a of the throttle pipe 12 is disposed at substantially the same position as the front end edge 13 a of the gear housing 13 in the front-rear direction (width direction). In FIG. 2, the downstream end 12 b of the throttle pipe 12 is disposed closer to the front end edge 13 a than the rear end edge 13 b in the front-rear direction (width direction) of the gear housing 13. As shown in FIG. 2, a part (rear side portion) 14 a of the outer peripheral surface of the motor housing 14 is disposed further downstream than the downstream end 12 b of the throttle pipe 12.

  As shown in FIGS. 1 to 3, the gear cover 3 is fastened and fixed to the gear housing 13 with screws 6 and nuts 7 so as to close the opening of the gear housing 13. The gear cover 3 includes a connector 3a for external wiring.

  FIG. 4 shows the throttle device 1 by a cross-sectional view taken along line AA of FIG. FIG. 5 is an enlarged cross-sectional view of a part of FIG. 4 for the throttle device 1. FIG. 6 is a right side view of FIG. 1 showing a state where the gear cover 3 is removed from the throttle device 1. FIG. 7 shows a state where the gear cover 3 is removed from the throttle device 1 by a cross-sectional view taken along line BB in FIG.

  In FIG. 4, a pair of boss portions 16A, 16B formed on the left and right side portions of the throttle pipe 12 are provided with a throttle shaft 4 crossing the bore 11a via a pair of first bearing 21A and second bearing 21B, respectively. It is rotatably supported. In this embodiment, both bearings 21A and 21B are constituted by sliding bearings formed of a relatively thin plate material. For this reason, the outer diameters of both the bearings 21A and 21B are relatively smaller than those of the bearing 83 (FIGS. 17 and 18) made of a conventional ball bearing. The throttle valve 5 fixed to the throttle shaft 4 has a disk shape corresponding to the shape of the bore 11 and rotates integrally with the throttle shaft 4. As a result, the amount of intake air flowing through the bore 11 is adjusted by opening and closing the bore 11.

  As shown in FIGS. 4 and 7, the throttle shaft 4 includes a first end 4a and a second end 4b. The first end 4a (the left end in FIGS. 4 and 7) of the throttle shaft 4 is rotatably supported by the first boss portion 16A via the first bearing 21A. A plug 22 that closes the opening 2 is attached to the first boss 16A. The vicinity of the second end 4b (the right end in FIGS. 4 and 7) of the throttle shaft 4 is rotatably supported by the second boss portion 16B via the second bearing 21B. Adjacent to the second bearing 21B, a seal member 23 is provided at the end of the second boss portion 16B to maintain airtightness with the throttle shaft 4. The second end 4 b protrudes into the gear housing 13. A throttle gear 31 having a sector gear is fixed to the second end 4b.

  As shown in FIG. 4, one end of the motor housing 14 opens into the gear housing 13. The motor housing 14 houses an electric motor 8 such as a DC motor, for example. A drive gear 32 is attached to the output shaft 8 a of the electric motor 8.

  As shown in FIG. 4, a countershaft 24 is provided between the throttle body 2 and the gear cover 3 between the throttle shaft 4 and the electric motor 8. A counter gear 33 is rotatably supported on the counter shaft 24. The counter gear 33 includes a large-diameter gear portion 33 a that meshes with the drive gear 32 and a small-diameter gear portion 33 b that meshes with the throttle gear 31. In this embodiment, the throttle gear 31, the drive gear 32, and the counter gear 33 constitute the gear mechanism 9 of the present invention that functions as a reduction gear mechanism.

  Here, the throttle gear 31 and its related configuration will be described in detail. FIG. 8 is a rear view of the throttle gear 31 together with related parts. Here, for convenience of explanation, in FIGS. 4 and 5, the side of the throttle gear 31 facing the throttle body 2 is the back side of the throttle gear 31, and the side of the throttle gear 31 facing the gear cover 3 is the throttle. The front side of the gear 31 is assumed. As shown in FIGS. 4 to 8, the throttle gear 31 is made of resin, and includes a disc-shaped gear body 31a and a fan-shaped gear portion 31b formed on the outer periphery of the gear body 31a. As shown in FIGS. 4 to 6, the gear portion 31 b meshes with the small diameter gear 32 b of the counter gear 33. The gear body 31a includes a cylindrical portion 31c that protrudes to the back side at a center portion thereof, and a peripheral wall portion 31d that similarly protrudes in the back-side axial direction around the cylindrical portion 31c. A deformed second end 4b of the throttle shaft 4 is fitted to the front side recess of the cylindrical portion 31c in a non-rotating state, and a metal caulking plate 25 joined by caulking the second end 4b is provided. It is provided concentrically.

  As shown in FIGS. 4 and 5, a pair of permanent magnets 41 and an arcuate yoke 42 interposed between the permanent magnets 41 in the circumferential direction are concentrically arranged in the front side recess of the cylindrical portion 31 c. Provided. As shown in FIGS. 4, 5 and 8, a return spring 43 is provided between the cylindrical portion 31c and the peripheral wall portion 31d. The return spring 43 is composed of a torsion coil spring and is arranged concentrically with the throttle shaft 4. As shown in FIG. 6, the first end 43 a of the return spring 43 is latched by a latching portion 2 a provided on the throttle body 2. Further, as shown in FIGS. 6 and 8, the second end 43 b of the return spring 43 is latched by a latching portion 31 e provided in the throttle gear 31. As a result, the return spring 43 constantly urges the throttle gear 31 in the closing direction in which the throttle valve 5 closes the bore 11.

  As shown in FIGS. 4 to 8, an opener spring 44 is provided on the outer periphery of the peripheral wall portion 31 d of the throttle gear 31. In this embodiment, the opener spring 44 is formed by bending a belt-like leaf spring into a C shape in plan view. As shown in FIGS. 6 and 8, the first end portion 44a and the second end portion 44b of the opener spring 44 are connected to the closing side latching portion 31f and the opening side locking portion 31g formed on the outer periphery of the gear body 31a. Each is latched. Both end portions 44 a and 44 b of the opener spring 44 protrude from the throttle gear 31 in the radial direction. The first end portion 44a serves as a closing position restricting portion for restricting the opener opening position and the fully closed position of the throttle valve 5. Further, the second end portion 44b is a fully open restricting portion for restricting the fully open position of the throttle valve 5.

  As shown in FIG. 6, when the throttle gear 31 is viewed from the front side, the first end portion 44a of the opener spring 44 is disposed at a predetermined angle away from one end of the gear portion 31b in the counterclockwise direction. . On the other hand, as shown in FIG. 6, the second end portion 44b of the opener spring 44 is disposed at a predetermined angle with respect to one end of the gear portion 31b in the counterclockwise direction.

  As shown in FIG. 6, a projecting opener stopper 13 c is provided in the gear housing 13. A first end 44a of an opener spring 44 provided on the throttle gear 31 can come into contact with the opener stopper 13c when the throttle valve 5 rotates in the closing direction. As shown in FIG. 6, the first end 44a of the opener spring 44 is hooked on the opener stopper 13c, so that the throttle valve 5 is held at an opener opening degree close to a fully closed state. Further, as shown in FIG. 6, a protrusion-like fully open stopper 13 d is provided in the gear housing 13. A second end 44b of an opener spring 44 provided on the throttle gear 31 can come into contact with the fully open stopper 13d when the throttle valve 5 rotates in the opening direction. Then, when the second end 44b of the opener spring 44 contacts the fully open stopper 13d, the maximum opening of the throttle valve 5, that is, the fully open position is restricted to a predetermined position.

  FIGS. 9 and 10 show the relationship among the throttle gear 31, the throttle body 2, the return spring 43, and the opener spring 44 by model views. FIG. 9 corresponds to a state in which the throttle valve 5 is held at the opener opening. In this state, the first end portion 44 a of the opener spring 44 is in contact with the opener stopper 13 c of the gear housing 13 while being latched by the closing side latch portion 31 f of the throttle gear 31, and the second end portion of the opener spring 44 is engaged. 44b is latched to the opening side latching portion 31g of the throttle gear 31. As a result, the throttle gear 31 is biased by the opener spring 44 in the direction of opening the throttle valve 5. Further, the throttle gear 31 is urged in a direction to close the throttle valve 5 by a return spring 43 provided between the throttle body 2 and the throttle gear 31. Then, due to the balance of the urging forces of the opener spring 44 and the return spring 43, the throttle valve 5 is held at the opener opening slightly opened from the fully closed state. In this embodiment, the opener opening state and the fully closed state described above correspond to the closed state of the present invention.

  From the state shown in FIG. 9, the electric motor 8 is operated to rotate the throttle shaft 4 via the gear mechanism 9 and the throttle valve 5 is rotated in the closing direction, whereby the throttle gear 31 shown in FIG. 9 is fully closed. The throttle gear 31 is rotated until the latching portion 31h contacts the first end portion 44a of the opener spring 44, and in this state, the throttle valve 5 is restricted to the fully closed position.

  On the other hand, FIG. 10 corresponds to a state in which the throttle valve 5 is held fully open. That is, this corresponds to a state in which the electric motor 8 is operated to rotate the throttle shaft 4 via the gear mechanism 9 and the throttle valve 5 is rotated to the fully open position. In this state, the first end portion 44a of the opener spring 44 is hooked on the closing side hook portion 31f of the throttle gear 31, and the second end portion 44b of the opener spring 44 is hooked on the open side hook portion 31g of the throttle gear 31. It abuts against the fully-open stopper 13d while being hooked on. As a result, the throttle gear 31 is rotated by the driving force of the electric motor 8 against the urging force of the return spring 43, a rotational torque is applied, and the throttle valve 5 is held fully open.

  As shown in FIGS. 4 and 5, adjacent to the throttle gear 31, between the throttle gear 31 and the gear housing 13, the opening of the bore 11 (throttle opening) by the throttle valve 5 is detected. A throttle sensor 10 is provided. The throttle sensor 10 includes an MRE (Magnet Resistive Element) element 45 provided on the gear cover 3 and a pair of permanent magnets 41 provided on the cylindrical portion 31 c of the throttle gear 31. The MRE element 45 is loosely fitted in the front side recess of the cylindrical portion 31c of the throttle gear 31. The MRE element 45 is configured as an element that detects the direction of the magnetic field generated between the pair of permanent magnets 41. As the MRE element 45, for example, a magnetic detection element such as a magnetoresistive element and a Hall element arranged so that the direction of the magnetic field can be detected, or a detection unit having the magnetic detection element is integrally provided with an arithmetic unit, An element or the like that outputs a corresponding signal can be used. The MRE element 45 detects the direction of the magnetic field generated between the pair of permanent magnets 41 as the rotation angle of the throttle gear 31, that is, the throttle opening of the throttle valve 5, and outputs a detection signal thereof. .

  In the above configuration, the driving force of the electric motor 8 by energization is transmitted to the throttle shaft 4 via the gear mechanism 9, that is, the driving gear 32, the counter gear 33 and the throttle gear 31. Thereby, the throttle valve 5 rotates and the bore 11 is opened and closed. At this time, the throttle gear 31 is rotated against the urging force of the return spring 43 in an opening range equal to or larger than the opener opening. Further, in the opening range below the opening of the opener, the throttle gear 31 is rotated against the urging force of the opener spring 44, and the first end 44 a of the opener spring 44 is connected to the fully closed latching portion 31 h of the throttle gear 31. By contacting, the rotation of the throttle gear 31 from the fully closed restriction position to the closing side is restricted. On the other hand, when the electric motor 8 is not energized, the throttle gear 31 is held at a predetermined opener opening by the balance between the urging force of the return spring 43 and the urging force of the opener spring 44.

  Next, the relationship among the throttle pipe 12, the throttle shaft 4, the throttle valve 5, and the two bearings 21A and 21B will be described. FIG. 11 schematically shows a cross-sectional view of the relationship between the throttle pipe 12, the throttle shaft 4, the throttle valve 5, and the two bearings 21A and 21B. FIG. 12 is a schematic sectional view showing a state where the throttle valve 5 and the inner wall of the bore 11 are frozen in the cold state in the state shown in FIG.

  As shown in FIG. 4, in the throttle body 2, both bearings 21 </ b> A and 21 </ b> B configured by sliding bearings are provided corresponding to the vicinity of the first end 4 a and the second end 4 b of the throttle shaft 4. As shown in FIG. 11, the bore 11 of the throttle pipe 12 has an upstream end 11a and a downstream end 11b with respect to the air flow in the axial direction thereof. The upstream end 11 a of the bore 11 corresponds to the upstream end 12 a of the throttle pipe 12, and the downstream end 11 b of the bore 11 corresponds to the downstream end 12 b of the throttle pipe 12. Both bearings 21A and 21B are disposed on the throttle body 2 so that the throttle shaft 4 is adjacent to the downstream end 11b of the bore 11 and the downstream end 12b of the throttle pipe 12. Here, the reason why the throttle shaft 4 can be arranged so as to be adjacent to the downstream end 12b of the throttle pipe 12 is that both the bearings 21A and 21B are constituted by sliding bearings made of thin plate materials.

As shown in FIG. 11, when the throttle valve 5 is in a closed state (FIG. 11 shows the opener opening state of the throttle valve 5) that substantially closes the bore 11, the throttle valve 5 has a diameter of the bore 11. The throttle valve 5 is disposed at a predetermined closing angle (opener opening) θ1 with respect to the direction, and the one end portion 5a of the throttle valve 5 is adjacent to the downstream end 11b of the bore 11 (the downstream end 12b of the throttle pipe 12). Be placed. Further, when the throttle valve 5 starts to open the bore 11, the one end portion 5a of the throttle valve 5 immediately protrudes from the bore 11 as shown by a two-dot chain line in FIG. When the one end portion 5a of the throttle valve 5 and the inner wall of the bore 11 freeze in the cold state in the closed state shown in FIG. 11, ice J1 is formed between the one end portion 5a and the inner wall of the bore 11 as shown in FIG. it can.

  FIG. 13 is a schematic sectional view showing a state in which a manifold pipe 51 of a resin intake manifold is connected to the throttle pipe 12 of this embodiment. As shown in FIG. 13, in this embodiment, one end 51a of a manifold pipe 51 constituting an intake manifold of the engine is connected to the downstream end 12b of the throttle pipe 12 corresponding to the downstream end 11b of the bore 11. . Here, the inner diameter D1 of the intake passage 52 in the manifold pipe 51 is larger than the inner diameter D2 of the bore 11 of the throttle pipe 12.

  As described above, according to the throttle device 1 of this embodiment, the first end portion 4a and the second end portion 4b of the throttle shaft 4 are formed by the first boss portion 16A and the second boss portion 16B of the throttle body 2. It is rotatably supported via the first bearing 21A and the second bearing 21B. The pair of bearings 21A and 21B is constituted by a sliding bearing formed of a plate material. Accordingly, the outer diameters of both the bearings 21A and 21B are smaller than those of the bearing 83 made of the conventional ball bearing. Then, both bearings 21A and 21B made of sliding bearings are arranged on the throttle body 2 so that the throttle shaft 4 is adjacent to the downstream end 11b of the bore 11. Therefore, as shown in FIGS. 11 and 12, the dimension of the length R1 from the center of the throttle shaft 4 to the downstream end 11b of the bore 11 is smaller than that of the bearing made of the ball bearing 83. For this reason, the length of the bore 11 in the axial direction can be shortened, the throttle pipe 12 can be downsized, and the throttle body 2 can be downsized.

  On the other hand, in this embodiment, as shown in FIGS. 11 and 12, when the throttle valve 5 is in the closed state, the throttle valve 5 is disposed at a predetermined closing angle, and the one end portion 5a of the throttle valve 5 is 11 is disposed adjacent to the downstream end 11b. The arrangement of the throttle valve 5 is such that one end portion 5a of the throttle valve 5 immediately protrudes from the bore 11 when the throttle valve 5 rotates and starts to open the bore 11. Therefore, as shown in FIG. 12, when the one end portion 5a of the throttle valve 5 and the inner wall of the bore 11 are frozen, the contact area S1 between the throttle valve 5 and the bore 11 and the ice J1 is smaller than that in the conventional example. For this reason, the ice J1 can be broken only by rotating the throttle valve 5 with a slight torque, and the freezing property of the throttle valve 5 and the inner wall of the bore 11 can be improved. Further, it is not necessary to provide a cylindrical core and an electric circuit made of a heat generating material as in the conventional example in order to release icing.

In this embodiment, the throttle sensor 10 includes a pair of permanent magnets 41 provided on the throttle gear 31 and an MRE element 45 that detects the direction of a magnetic field generated between the pair of permanent magnets 41. Then, when the MRE element 45 detects the direction of the magnetic field of the pair of permanent magnets 41, the opening degree of the bore 11 (throttle opening degree) by the throttle valve 5 is detected. Therefore, for example, even if the magnetic field strength of the permanent magnet 41 changes due to a positional shift of the permanent magnet 41 due to a positional shift of the throttle shaft 4 or a temperature change, the direction of the magnetic field of the permanent magnet 41 is not affected. That is, even if a change occurs in the magnetic field intensity of the permanent magnet 41, the throttle opening is detected by the MRE element 45 based on the direction of the magnetic field without being affected by the change. This is suitable for the throttle device 1 of the present embodiment that rotatably supports the throttle shaft 4 using both bearings 21A and 21B made of relatively simple sliding bearings. For this reason, the throttle device 1 using both bearings 21A and 21B made of a sliding bearing can be ensured without reducing the detection accuracy of the throttle opening.

  In this embodiment, the motor housing 14 is disposed with a gap with respect to the throttle pipe 12. Further, the motor housing 14 and the throttle shaft 4 are parallel to each other, and the rear side portion 14a which is a part of the outer peripheral surface of the motor housing 14 is disposed further downstream than the downstream end 11b of the bore 11 of the throttle pipe 12. The Accordingly, the surface area of the motor housing 14 itself increases. For this reason, the heat dissipation of the electric motor 8 by the motor housing 14 can be improved.

  In this embodiment, as shown in FIG. 13, one end 51 a of the manifold pipe 51 is connected to the downstream end 12 b of the throttle pipe 12, and the inner diameter D1 of the intake passage 52 in the manifold pipe 51 is It is larger than the inner diameter D2 of the bore 11. Therefore, the moisture in the bore 11 can easily flow into the intake passage 52 of the manifold pipe 51. In this sense, icing between the throttle valve 5 and the inner wall of the bore 11 can be reduced. When the throttle valve 5 starts to open the bore 11, the one end portion 5a of the throttle valve 5 immediately protrudes from the bore 11 to the intake passage 52 of the manifold pipe 51 having a large inner diameter. Accordingly, the intake flow rate of the bore 11 increases nonlinearly at the beginning of opening of the throttle valve 5. FIG. 14 is a graph showing the characteristics of the intake air flow rate with respect to the throttle opening degree in this embodiment. As shown in FIG. 14, the intake flow rate characteristic shows that the intake flow rate temporarily increases when the throttle valve 5 starts to open, and thereafter the intake flow rate increases linearly according to the throttle opening. For this reason, the intake flow rate characteristic by the throttle device 1 can be easily and arbitrarily changed. Further, it is possible to suppress the generation of abnormal noise due to the intake air at the beginning of opening of the throttle valve 5.

Second Embodiment
Next, a second embodiment in which the throttle device of the present invention is embodied will be described in detail with reference to the drawings.

  In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described.

  This embodiment is different from the first embodiment in the shape of the manifold pipe 51 connected to the throttle pipe 12. FIG. 15 is a schematic sectional view showing a state in which the manifold pipe 51 is connected to the throttle pipe 12. That is, in this embodiment. As shown in FIG. 15, the intake passage 52 in the manifold pipe 51 is formed so as to gradually decrease in diameter from one end 51 a of the manifold pipe 51 to the downstream side.

  Accordingly, since the intake passage 52 of the manifold pipe 51 gradually decreases in diameter from the one end 51a to the downstream side, the intake flow rate of the bore 11 increases nonlinearly at the beginning of opening of the throttle valve 5. Further, after the throttle valve 5 starts to open, the intake air flow rate of the bore 11 gradually increases according to the throttle opening. FIG. 16 is a graph showing the characteristics of the intake air flow rate with respect to the throttle opening degree in this embodiment. As shown in FIG. 16, the intake flow rate characteristic shows that the intake flow rate temporarily increases at the beginning of opening of the throttle valve 5, and thereafter the intake flow rate gradually increases according to the throttle opening. For this reason, the intake flow rate characteristic by the throttle device 1 can be easily and arbitrarily changed. Further, it is possible to suppress the generation of abnormal noise due to the intake air at the beginning of opening of the throttle valve 5.

  Note that the present invention is not limited to the above-described embodiments, and a part of the configuration can be changed as appropriate without departing from the spirit of the invention.

  For example, in each of the above embodiments, the opener spring 44 is configured by a leaf spring, but it can also be configured by a torsion coil spring in the same manner as the return spring.

  The present invention can be used for engines such as automobiles. Specifically, it can be used to adjust the intake air amount in the intake passage of the engine.

1 throttle device 2 throttle body 4 throttle shaft 4a first end 4b second end 5 throttle valve 5a one end 8 electric motor 9 gear mechanism 10 throttle sensor 11 bore 11a upstream end 11b downstream end 12 throttle pipe 12a upstream End 12b Downstream end 14 Motor housing 14a Rear side portion 16A First boss portion 16B Second boss portion 21A First bearing 21B Second bearing 31 Throttle gear 32 Drive gear 33 Counter gear 41 Permanent magnet 45 MRE element 51 Manifold pipe 51a One end 52 Intake passage L1 Center axis (of motor housing)
D1 Inner diameter (in the intake passage)
D2 Inner diameter (bore)

Claims (5)

A throttle body having a bore;
A throttle shaft that is disposed across the bore and is rotatably supported by the throttle body via a bearing;
A throttle valve provided on the throttle shaft in the bore and opening and closing the bore by rotation of the throttle shaft;
A gear mechanism including a throttle gear provided on the throttle shaft;
An electric motor drivingly connected to the gear mechanism, and rotating the throttle shaft via the gear mechanism by the electric motor, thereby changing the opening of the bore by the throttle valve and flowing through the bore A throttle device for adjusting the amount of air,
The throttle shaft includes a first end and a second end, and the bearing is provided corresponding to the vicinity of the first end and the second end,
The both bearings are constituted by sliding bearings formed of a plate material,
The bore has an upstream end and a downstream end in the axial direction with respect to the air flow, and the bearings are disposed on the throttle body such that the throttle shaft is adjacent to the downstream end of the bore;
When the throttle valve is in a closed state that substantially closes the bore, the throttle valve is disposed at a predetermined closing angle with respect to the radial direction of the bore, and one end of the throttle valve is located downstream of the bore. Placed adjacent to the edge,
When the throttle valve starts to open the bore, the one end of the throttle valve protrudes from the bore. A throttle sensor for detecting the opening of the bore by the throttle valve;
The throttle gear is fixed to the second end of the throttle shaft, and the throttle sensor is provided adjacent to the throttle gear;
2. The throttle sensor according to claim 1, wherein the throttle sensor includes a pair of permanent magnets provided in the throttle gear, and an MRE element that detects a direction of a magnetic field generated between the pair of permanent magnets. Throttle device. The throttle body includes a throttle pipe having the bore, and a motor housing that houses the electric motor,
The motor housing is disposed with a gap with respect to the throttle pipe, and a part of the outer peripheral surface of the motor housing is disposed further downstream than the downstream end of the bore. The throttle device according to claim 1 or 2. The throttle body includes a throttle pipe having the bore,
One end of a manifold pipe constituting an intake manifold of an engine is connected to the downstream end of the throttle pipe corresponding to the downstream end of the bore, and the inner diameter of the intake passage in the manifold pipe is the inner diameter of the bore The throttle device according to claim 1, wherein the throttle device is larger than the throttle device.   The throttle device according to claim 4, wherein the intake passage in the manifold pipe gradually decreases in diameter from one end of the manifold pipe to the downstream side.

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