JP2013253490A - Throttle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a throttle device causing air of an air chamber to smoothly flow out during assembly of a bearing and obtaining superior sealing function after the assembly.SOLUTION: A throttle device comprises: a ventilation passage 70 on an outer peripheral surface of a bearing 40, as a mechanism for opening/blocking an air chamber 60 formed between an oil seal 30 and the bearing 40 to/from the outside; and a sealing means 80 blocking the air chamber 60 and the ventilation passage 70 by press fitting the bearing 40 into a predetermined press fitting position. Accordingly, during the assembly of the bearing 40, the air in the air chamber 60 is caused to flow to the outside via the ventilation passage 70, and the assembly is thereby normally performed without requiring excessive assembly force. Furthermore, after the assembly of the bearing 40, because the air chamber 60 and the ventilation passage 70 are blocked by the sealing means 80, even when the sealing function of the oil seal 30 is deteriorated, good sealing function is secured by the sealing means 80.

Description

  The present invention relates to a throttle device for an internal combustion engine, for example, a throttle device for a supercharged internal combustion engine mounted on a vehicle such as an automobile.

[Conventional technology]
In this type of throttle device, in particular, in the throttle valve mounting structure (throttle shaft bearing structure) that is pivotally supported by the throttle body, the airtight structure of the shaft housing portion through which the throttle shaft is inserted and held in the throttle body, It is one of the important issues how to build under the constraints of miniaturization and price reduction, and various configurations have been proposed and put into practical use.

The typical throttle device is formed through the passage wall of the throttle body, and a shaft housing portion through which the throttle shaft is inserted and held has an intake passage side inner peripheral surface of the shaft housing portion and an outer peripheral surface of the throttle shaft. Between the oil seal that airtightly closes the intake passage side opening of the shaft housing portion and the inner surface of the shaft housing portion on the side opposite to the intake passage and the outer peripheral surface of the throttle shaft. A bearing that rotatably supports the throttle shaft and hermetically closes the opening on the side opposite to the intake passage of the shaft housing (for example, a ball bearing with a lip seal, hereinafter simply referred to as a bearing or a rolling bearing). It has.
That is, the airtightness of the shaft housing portion through which the throttle shaft is inserted and held is functionally divided into an oil seal arranged in series in the axial direction and a bearing with a sealing function to ensure a two-stage closed structure.

  However, in such a two-stage closed structure, when the oil seal and the bearing are sequentially assembled, the boundary space (air chamber) between the oil seal and the bearing is hermetically sealed due to hermeticity, and the air inside It may be compressed and generate repulsive force, and normal assembly may not be possible. Even if it can be assembled, an excessive force is exerted on each component to cause distortion, and the sealing function may be deteriorated.

  Therefore, when an air chamber is formed between the oil seal and the bearing, the air confined in the air chamber is compressed and no repulsive force is generated, so that an excessive assembling force or assembling man-hour is required at the time of assembling. Has been proposed, and a throttle device having a bearing structure that does not cause distortion even after assembly has been proposed (see, for example, Patent Document 1).

  The throttle device disclosed in Patent Document 1 has an air vent hole for communicating an air chamber formed between the oil seal and the bearing and the outside (functional component housing chamber) in the shaft housing portion or the throttle shaft. Is provided. As a result, even if the bearing is assembled after the oil seal is assembled to the shaft housing portion, the air between the oil seal and the bearing leaks out from the air vent hole, so that it is not compressed and generates a repulsive force. Thus, normal assembly can be performed without requiring an extra assembly force.

(Problems of conventional technology)
However, the throttle device provided with the air vent hole has the following problems in practical use.
(1) Even if it is outside, the functional part storage chamber contains functional parts such as a drive motor and a gear reduction device. Therefore, if the airtightness of the oil seal is impaired, moisture mixed in the intake air and corrosiveness The component may enter the functional component storage chamber through the air vent hole, and malfunction (such as rusting of the drive motor and water absorption of the resin gear) may occur in the functional component.
(2) As a solution, it is conceivable to use a special seal structure that exhibits high airtightness, for example, a large oil seal that is reinforced with a large seal area. However, the airtight function is differentiated to reduce the size and price. It would be hard to adopt because it would go against the intended goal of planning.
(3) Although it is conceivable to attach a seal member to the air release hole, it is difficult to adopt because the original function of the air release hole is lost.

  The present inventor has conducted various experiments and researches in order to find out such a problem. By skillfully utilizing the assembly process (press-fit process) of the bearing, the present inventor can respond to the press-fit amount of the bearing during assembly. Thus, the present inventors have found an effective technique that allows air in the air chamber to escape and allows the air chamber to be substantially sealed after assembly of the bearing.

JP 2009-162085 A

  The present invention has been made in view of the above circumstances. The purpose of the present invention is to reduce the repulsive force by compressing the air in the air chamber when assembling the bearing under the constraints of miniaturization and cost reduction. It is an object of the present invention to provide a throttle device that does not require any extra assembling force or man-hours and that can provide a good sealing function after assembling.

[Means of Claim 1]
According to the first aspect of the present invention, as a mechanism for opening or shutting off the air chamber formed between the oil seal and the bearing in the shaft housing portion, the anti-intake of the shaft housing portion is used. An air passage that is formed on a part of the inner peripheral surface of the passage side or the outer peripheral surface (press-fit surface) of the throttle shaft and communicates the air chamber and the anti-air chamber side of the bearing, and the bearing is the anti-intake passage of the shaft housing portion Sealing means for blocking communication between the air chamber and the air passage is provided by press-fitting from the side to a predetermined position.

  As a result, even if the bearing is assembled by press fitting after the oil seal is assembled to the shaft housing portion, the air between the oil seal and the bearing flows out to the outside via the air passage according to the press-fit amount of the bearing. Since it is compressed and does not generate a repulsive force, it can be normally assembled without requiring an extra assembling force. In addition, since the communication between the air chamber and the air passage is blocked by the sealing means after the bearing is assembled, a good sealing function can be obtained by the sealing means even if the airtightness of the oil seal is impaired. .

It is sectional drawing which showed the whole structure of the throttle device (Example 1). It is a typical enlarged view which shows the detailed structure of a shaft accommodating part, (a) is sectional drawing when not using an especially independent sealing member as a sealing means, (b) is a front view of a bearing single-piece | unit (implementation) Example 1). It is a typical enlarged view which shows the detailed structure of a shaft accommodating part, (a) is sectional drawing at the time of using a convex-shaped (single lip) seal member specially as a sealing means, (b) is a sealing means FIG. 5 is a cross-sectional view when a double lip-shaped seal member is specially used (Example 2). It is a typical enlarged view showing the detailed structure of the shaft housing part, (a) is a front view of the bearing alone, (b) is a sectional view showing the state at the start of the assembly of the bearing, (c) is the completion of the assembly of the bearing It is sectional drawing which shows the state of time (Example 3). It is an expanded sectional view which shows a reference example as a structure of a shaft accommodating part.

BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described based on examples shown in the drawings.
First, the overall structure of a throttle device to which the present invention is applied will be outlined with reference to FIG. 1, and then the main part of each embodiment of the present invention will be described in detail with reference to FIGS.

[Configuration of Example 1]
As shown in FIG. 1, the throttle device 1 adjusts the amount of intake air supplied to an internal combustion engine, for example, a supercharged internal combustion engine (hereinafter simply referred to as an engine, not shown) mounted on an automobile. The following various parts 2 to 10 are provided as main components.

  That is, a throttle body 2 having a passage through which intake air sucked into each cylinder of the engine flows in the direction of the central axis, that is, an intake passage 21 constituting an intake system of the engine is used as a machine base. A throttle valve 3 that opens and closes 21 and adjusts the amount of intake air to be sucked, a throttle shaft 4 that pivots on the throttle body 2 while rotating the throttle valve 3, and a throttle shaft 4 A drive motor (actuator) 5 that rotates, a return spring (valve urging means) 6 such as a coil spring that urges the throttle valve 3 and the throttle shaft 4 in the fully closed direction, and a rotation output of the drive motor 5 is a throttle valve. 3 and a gear reduction device (power transmission device) 7 for transmitting to the throttle shaft 4; A throttle position sensor 8 that converts the opening degree of the lottle valve 3 into an electric signal (throttle opening signal) and outputs how much the throttle valve 3 is open, the drive motor 5, the gear reduction device 7, and the throttle position. A cover 10 that constitutes a functional component housing chamber 9 for housing the sensor 8 and the like together with the throttle body 2 is assembled.

  The throttle device 1 is connected to an engine control device (engine control unit: hereinafter referred to as ECU, not shown) that controls energization of the drive motor 5, and the amount of depression of the accelerator pedal (not shown) of the automobile (accelerator) The engine output and the rotational speed are controlled by adjusting the amount of intake air flowing into the engine based on the operation amount. The ECU is connected to a throttle position sensor 8 for outputting the opening degree of the throttle valve 3 and converts the depression amount of the accelerator pedal into an electric signal (acceleration opening degree signal) and outputs the accelerator operation amount to the ECU. An accelerator opening sensor (not shown) is connected.

  The throttle body 2 is manufactured, for example, by die casting using a light metal material such as aluminum. The passage wall 22 that surrounds the intake passage 21 has one end side (the left end side in the drawing) and the other end side (the left end side in the figure). Shaft accommodating portions 23 and 24 are inserted through and held in the shape of holes.

  One end portion 4 a of the throttle shaft 4 is rotatably inserted into the shaft housing portion 23 through a bearing (for example, a sliding bearing) 11 and a plug (blind plug) 12 in an airtight manner. The shaft housing 24 has the other end 4b of the throttle shaft 4 from a bearing device A (oil seal 30, bearing (rolling bearing) 40, air chamber 60, air passage 70, seal means 80, etc., which will be described in detail later. Through the airtightly and rotatably.

  The throttle valve 3 is formed in a substantially disk shape with a metal material or a resin material, and is a butterfly valve for opening and closing the intake passage 21 and adjusting the amount of intake air taken into the engine. The throttle valve 3 is rotated. The throttle shaft 4 is fixed to the throttle shaft 4 with a fastener 4d such as a screw in a state where the throttle shaft 4 is fitted in a valve insertion hole 4c formed in the valve holding portion of the throttle shaft 4.

  The throttle shaft 4 is formed in a round bar shape from a metal material, and the tip of the other end 4 b protrudes from the shaft accommodating portion 24 of the throttle body 2 into the functional component accommodating chamber 9. A valve gear 71, which is one of the components of the gear reduction device 7, is attached to the tip of the other end 4 b of the throttle shaft 4.

  The gear reduction device 7 reduces the rotational speed of the drive motor 5 to the rotational speed of the throttle shaft 4, and rotates with the valve gear 71 fixed to the other end 4 b of the throttle shaft 4 engaging with the valve gear 71. Intermediate gear 72, and a pinion gear 73 fitted to the motor shaft 5a of the drive motor 5. The drive motor 5 is an electric actuator (drive source) in which the motor shaft 5 a can rotate forward and backward when energized, and is housed in a recess 25 formed in the throttle body 2.

  The valve gear 71 is integrally formed of a resin material into a predetermined substantially annular shape, and a gear portion 71a that meshes with the small-diameter gear 72a of the intermediate gear 72 is integrally formed on the outer peripheral surface of the valve gear 71 on the lower side in the figure, It is partially formed. Here, the gear portion 71 a partially formed on the outer peripheral surface of the valve gear 71 is formed in a range slightly exceeding approximately 90 degrees which is the maximum opening of the throttle valve 3. And the other outer peripheral part of the valve gear 71 comprises the boss | hub part in which the gear part 71a is not formed, and when the throttle valve 3 is fully closed by this boss | hub part, the to-be-latched part latched by the fully closed position stopper 13 A fully-closed stopper portion 71b is integrally formed.

  The intermediate gear 72 is integrally formed in a predetermined shape with a resin material, and is rotatably inserted into an intermediate shaft 74 that forms the center of rotation. The intermediate gear 72 is provided with a small diameter gear 72 a that meshes with the valve gear 71 and a large diameter gear 72 b that meshes with the pinion gear 73. Here, one end of the intermediate shaft 74 is press-fitted and fixed in a recess formed in the outer wall surface of the passage wall 22 of the throttle body 2, and the other end is in a recess formed in the inner wall surface of the cover 10. It is fitted and fixed.

  The pinion gear 73 is a drive gear that is integrally formed of a metal material into a predetermined shape, is fitted on the motor shaft 5a of the drive motor 5, and rotates integrally. Here, the intermediate gear 72 and the pinion gear 73 are torque transmission means for transmitting the rotational torque of the drive motor 5 to the valve gear 71.

  The return spring 6 includes a return spring portion 6a and a default spring portion 6b, and the return spring portion 6a and the default spring portion 6b are coil springs having different winding directions. A U-shaped hook portion 6c that is bent into a substantially inverted U shape and is held by the intermediate opening stopper 14 is formed at the coupling portion between the return spring portion 6a and the default spring portion 6b.

  The return spring portion 6a is a first spring having a return function for forming a spring steel material in a coil shape and biasing the throttle valve 3 back from the fully open position to the intermediate position. The default spring portion 6b is a second spring having an open function for forming a spring steel material in a coil shape and biasing the throttle valve 3 back from the fully closed position to the intermediate position.

  The cover 10 is made of a thermoplastic resin that electrically supports and supports the throttle position sensor 8, and is attached to the opening side of the other end of the throttle body 2. A functional component housing chamber 9 for housing the device 7, the throttle position sensor 8 and the like is formed.

  In the throttle device 1 configured as described above, the bearing device A that forms the center of the present invention is constructed by a peripheral structure portion of the shaft housing portion 24 through which the other end portion 4b of the throttle shaft 4 is inserted and held. In particular, the bearing device A employed in this embodiment has a detailed configuration as shown in FIG.

  That is, in FIG. 2A, the bearing device A is housed and held between the inner circumferential surface on one end side (the intake passage 21 side) of the shaft housing portion 24 and the outer circumferential surface of the throttle shaft 4. The oil seal 30 that closes the opening on one end side (the intake passage 21 side) of the cylinder and the inner peripheral surface on the other end side (the anti-intake passage side) of the shaft housing 24 and the outer peripheral surface of the throttle shaft 4 are press-fitted. A bearing 40 that is accommodated and held so as to rotatably support the throttle shaft 4 and closes the opening on the other end side (the anti-intake passage side) of the shaft accommodating portion 24 is provided as a basic component.

  In addition to the oil seal 30 and the bearing 40 arranged in series on the throttle shaft 4, the bearing device A includes a stepped hole portion 50 formed in the shaft housing portion 24, the oil seal 30 and the bearing 40. It is characterized in that it includes an air chamber 60 formed therebetween, an air passage 70 provided on the outer peripheral surface of the bearing 40, and a sealing means 80 described later.

  First, as shown in FIG. 2B, a semicircular groove 40 a is provided on the outer peripheral surface of the bearing 40. The groove 40 a extends over the entire length from one end to the other end of the bearing 40 in the axial direction, and has a ventilation path 70 that allows the air chamber 60 to communicate with the anti-air chamber side (functional component housing chamber 9) of the bearing 40. It is composed.

Further, the stepped hole portion 50 formed in the shaft housing portion 24 is located on the intake passage 21 side, is located on the opposite side of the intake passage 21 with the small-diameter hole portion 51 that houses the oil seal 30, and the bearing 40. A large-diameter hole portion 52 to be accommodated and a stepped surface 53 that defines both the hole portions 51 and 52 are provided. The stepped surface 53 functions as a positioning stepped surface that regulates a predetermined press-fitting position of the bearing 40 when the air chamber side end surface 40b of the bearing 40 comes into contact therewith.
Furthermore, since the stepped surface 53 and the air chamber side end surface 40b of the bearing 40 come into contact (contact by pressure contact), the air chamber 60 is substantially sealed, so the air chamber 60 and the air passage 70 ( A sealing means 80 for blocking communication with the concave groove 40a) is formed.

The bearing 40 forms a bearing with a sealing function. As shown in FIG. 2A, the bearing 40 is slidably accommodated between an inner ring 41 and an outer ring 42 that form raceways, and the inner ring 41 and the outer ring 42. A steel ball (rolling element) 43 that rolls between the raceway surface of the inner ring 41 and the raceway surface of the outer ring 42, and between the inner ring 41 and the outer ring 42, at both ends in the axial direction from the steel ball 43. The first and second lip seals 44 and 45 are respectively mounted, and are constituted by ball bearings with lip seals that rotatably support the other end portion 4b of the throttle shaft 4 by rolling friction of the steel balls 43. In addition, except for the additional structure of the outer ring 42 (concave groove 40a), it is basically a general-purpose type.
In the outer ring 42 of the bearing 40, a concave groove 40 a (as an additional structure is provided on a part of the outer peripheral surface (the outer peripheral surface of the bearing 40) that is press-fitted into the large-diameter hole portion 52 of the stepped hole portion 50 of the shaft accommodating portion 24. A ventilation path 70) is provided.
Further, one end surface of the outer ring 42 forms an air chamber side end surface 40b of the bearing 40, and the air chamber side end surface 40b abuts on the stepped surface 53 of the stepped hole 50, whereby the bearing 40 has a predetermined surface. The press-fitting position of the air chamber 60 is restricted, and a sealing means 80 that blocks communication between the air chamber 60 and the concave groove 40a (ventilation passage 70) is configured.

  The oil seal 30 is a general-purpose one used as a sealing device for the rotating shaft to prevent the inflow of foreign matter from the outside while preventing the outflow of fluid in the device. The specific configuration is the same as the oil seal disclosed as “oil seal 19” in Patent Document 1, and the description thereof is omitted.

[Operation and Effect of Example 1]
Next, the operation and effect of the throttle device 1 of the present embodiment will be described using the assembly process of the oil seal 30 and the bearing 40.
The oil seal 30 is first assembled to the small diameter hole 51 with respect to the stepped hole 50 of the shaft housing portion 24, and then the bearing 40 is press-fitted into the large diameter hole 52. At this time, press-fitting of the bearing 40 is started from the side opposite to the intake passage, but the air chamber 60 formed between the oil seal 30 and the bearing 40 has a concave groove 40a (ventilation path 70) of the bearing 40. ) To the functional component storage chamber 9. Therefore, although the volume of the air chamber 60 is reduced by the press-fitting of the bearing 40, the air in the air chamber 60 flows out into the functional component housing chamber 9 via the concave groove 40a.
As a result, even if the bearing 40 is assembled after the oil seal 30 is assembled, the air between the oil seal 30 and the bearing 40 is not compressed and a repulsive force is not generated, and the bearing 40 is satisfactorily press-fitted. Can be assembled to the position.

Thus, when the bearing 40 is press-fitted to a predetermined press-fitting position (a position where the air chamber side end surface 40b of the outer ring 42 of the bearing 40 contacts the stepped surface 53), the assembly of the bearing 40 is completed.
After the assembly of the bearing 40, the sealing means 80 is constituted by the contact (contact by pressure contact) between the air chamber side end surface 40b of the outer ring 42 of the bearing 40 and the stepped surface 53. Communication with the groove 40a (ventilation path 70) is blocked, and the air chamber 60 can be substantially sealed.
Therefore, even if the sealing function of the oil seal 30 is impaired, the air passage 70 is well sealed by the sealing means 80, so that moisture and corrosive components mixed in the intake air can be passed through the air passage 70 through the functional component storage chamber. 9, there is no risk of malfunction (such as rusting of the drive motor 5, water absorption of the resin valve gear 71 and the intermediate gear 72) in the functional parts.

[Configuration of Example 2]
Next, a second embodiment of the present invention will be described with reference to FIG.
In the first embodiment, the sealing means 80 is configured without using any separate sealing member, whereas in the second embodiment, the sealing means 81 and 82 having a simple structure are additionally used to form the sealing means. 80 is an example in which two embodiments are shown as specific structural examples.
In addition, the same code | symbol is attached | subjected to the same or equivalent part as Example 1, and detailed description is abbreviate | omitted.

In the first embodiment shown in FIG. 3A, the stepped surface 53 of the stepped hole 50 and the simple convex (single lip) seal member 81 are the essential components of the seal means 80. It is used.
The stepped surface 53 only faces the air chamber side end surface 40b of the bearing 40, and does not restrict the press-fitting position of the bearing 40. The seal member 81 is fixed between the stepped surface 53 and the air chamber side end surface 40b of the bearing 40 so as to be separable from the other surface. .

  In particular, the seal member 81 is formed of a rubber-based elastic material and has an annular body (cylindrical body) having a simple convex lip portion 81a on one end side, and the other end side is on the air chamber side of the bearing 40. When the bearing 40 is press-fitted to a predetermined press-fitting position by being attached and fixed to the end face 40b (in this case, particularly the end face of the first lip seal 44 made of the same material) by, for example, an adhesive means, the lip portion 81a is brought into the stepped surface 53. By pressing and sealing between both surfaces (between the stepped surface 53 and the air chamber side end surface 40b of the bearing 40), the communication between the air chamber 60 and the concave groove 40a forming the air passage 70 is blocked. ing.

On the other hand, in the second embodiment shown in FIG. 3 (b), the stepped surface 53 of the stepped hole 50 and the double lip-shaped seal member 82 are used as essential components of the sealing means 80. Yes.
And like said 1st Embodiment, the stepped surface 53 only faces the air chamber side end surface 40b of the bearing 40, and does not regulate the press-fitting position of the bearing 40. Between the stepped surface 53 and the air chamber side end surface 40b of the bearing 40, it is fixed to one surface of the bearing 40 and is arranged in a state where it can be separated from the other surface.

  In particular, the seal member 82 is formed of a rubber-based elastic material and has an annular body (cylindrical body) having double lip portions 82a and 82b on one end side, and the other end side is on the air chamber side of the bearing 40. The end face 40b (in this case, in particular, the end face of the first lip seal 44 made of the same material) is attached and fixed by, for example, adhesive means. When the bearing 40 is press-fitted to a predetermined press-fitting position, the lip portions 82a and 82b are stepped. The contact between the air chamber 60 and the concave groove 40b forming the ventilation path 70 is cut off by pressing against the surface 53 and sealing between the two surfaces (between the step surface 53 and the air chamber side end surface 40b of the bearing 40). It is configured to do.

[Operation and Effect of Example 2]
Also in the second embodiment configured as described above, in the assembly process (press-fitting process) of the bearing 40, the lip portions 81a, 82a, and 82b of the seal members 81 and 82 are separated from the stepped surface 53. Even if the volume of the air chamber 60 between the oil seal 30 and the bearing 40 is reduced by the press-fitting of the bearing 40, the air inside flows out to the functional component housing chamber 9 through the concave groove 40a (ventilation passage 70). Therefore, air is not compressed by the assembly of the bearing 40.
Further, after the assembly of the bearing 40 (after being press-fitted to a predetermined press-fitting position), the lip portions 81a, 82a, 82b of the seal members 81, 82 are brought into pressure contact with the stepped surface 53, and sealing means 80 by this pressure contact is provided. Thus, the communication between the air chamber 60 and the groove 40a (ventilation path 70) is blocked, and the air chamber 60 can be substantially sealed.
Therefore, even if the sealing function of the oil seal 30 is impaired, there is no possibility that moisture and corrosive components mixed in the intake air may enter the functional component housing chamber 9 through the air passage 70.

  In Example 2 described above, in any of the embodiments, the seal members 81 and 82 are attached and fixed to the bearing 40 side. However, the attaching direction of the seal members 81 and 82 is reversed, and the seal members 81 and 82 are attached. Even if one end side is attached and fixed to the stepped surface 53 and the lip portions 81a, 82a, and 82b on the other end side are arranged so as to be detachable from the air chamber side end surface 40b of the bearing 40, Of course, the same effect as that of the embodiment can be obtained.

[Modifications of Examples 1 and 2]
In the first and second embodiments, the bearing 40 constituting the press-fitting surface is formed when forming the air passage 70 that communicates the air chamber 60 and the anti-air chamber side of the bearing 40 in a part of the press-fitting surface of the bearing 40. Of the outer peripheral surface of the shaft and the inner peripheral surface of the shaft accommodating portion 24 (large diameter hole portion 52), only the outer peripheral surface of the bearing 40 (the outer peripheral surface of the outer ring 42) is used to form a semicircular recess that forms the air passage 70. Although the groove 40a is provided, a semicircular concave groove corresponding to the concave groove 40a may be provided only on the inner peripheral surface of the shaft accommodating portion 24 (large diameter hole portion 52).
In this way, the concave groove can be integrally formed when the die body of the throttle body 2 is manufactured, and a special additional structure is not required for the bearing 40, so that the general-purpose type can be used as it is. There is.

In addition, when it is desired to increase the flow area of the air passage 70, the semicircular concave grooves are provided on both the outer peripheral surface of the outer ring 42 and the inner peripheral surface of the large-diameter hole portion 52, respectively. You may form in the ventilation path 70 of a shape.
Further, the shape of the concave groove as the air passage 70 is not limited to a semicircular shape, and may be a rectangular shape. Instead of the groove, a part of the circumference of the press-fitting surface is omitted to form an arc shape. A so-called oval shape may be used.

[Configuration of Example 3]
Next, Embodiment 3 of the present invention will be described with reference to FIG.
In the third embodiment, as in the first embodiment, the sealing means 80 is constructed without using an independent seal member. However, a higher sealing performance can be obtained as compared with the first embodiment. .
In addition, the same code | symbol is attached | subjected to the same or equivalent part as Example 1, and detailed description is abbreviate | omitted.

  As shown in FIG. 4A, the bearing 40 is provided with one rectangular concave groove 40a and three rectangular concave grooves 40c on the outer peripheral surface of the outer ring 42 at intervals of 90 °. On the other hand, on the inner peripheral surface of the large-diameter hole portion 52 of the shaft accommodating portion 24, a single short rectangular shape is provided at a position corresponding to the concave grooves 40a and 40c, as shown in FIGS. A shaped projection 54 and three long rectangular projections 55 are provided.

Of the four concave grooves 40 a and 40 c, one concave groove 40 a forms the air passage 70. One short projection 54 corresponding to the concave groove 40a is formed in the vicinity of the joint portion with the stepped surface 53, and is fitted in only the air chamber 60 side of the concave groove 40a in a press-fit state. It has a sealing projection that closes.
Each of the three long protrusions 55 is fitted into the concave groove 40c and has an axial length longer than the axial length of the concave groove 40c, that is, an axial length longer than the axial length of the bearing 40. . The three concave grooves 40c and the protrusions 55 form guide grooves and guide protrusions that guide the press-fitting of the bearing 40.
And the sealing means 54 which interrupts | blocks communication with the air chamber 60 and the ventilation path 70 is comprised by the protrusion 54 for a seal | sticker being press-fit in the concave groove 40a which makes the ventilation path 70.

[Operation / Effect of Example 3]
According to the above configuration, at the initial assembly of the bearing 40, as shown in FIG. 4B, the bearing 40 is press-fitted while being guided by being fitted with the guide protrusion 55 in the guide groove 40c. . The insertion position of the bearing 40 in the circumferential direction can be reliably determined by the insertion of the concave groove 40 c and the protrusion 55. On the other hand, the concave groove 40a forming the air passage 70 is separated from the sealing projection 54 and is in an open state.
As a result, the air in the air chamber 60 whose volume is reduced as the press-fitting of the bearing 40 progresses smoothly through the concave groove 40a (ventilation passage 70) to the functional component housing chamber 9 and is compressed. The bearing 40 can be assembled well.
Thus, when the bearing 40 is press-fitted to a predetermined press-fitting position (assembly is completed), the sealing projection 54 is fitted in the concave groove 40a forming the ventilation path 70 in a press-fitted state, and the sealing means 80 is configured. The concave groove 40a is closed. That is, the air chamber 60 can be sealed, and a sealing effect can be ensured even if the oil seal 30 is damaged.

  In the present embodiment, the concave groove 40a forming the air passage 70 and the sealing projection 54 are fitted immediately before the completion of the assembly of the bearing 40, so that this fitting can be carried out accurately and quickly and smoothly. In addition, the guide groove 40c and the protrusion 55 that determine the circumferential insertion position of the bearing 40 are important means. The degree of fitting of the guide groove 40c and the protrusion 55 is determined by press-fitting ("tightening"). “Fitting”), it takes time, so it is desirable to make “Fitting” or “Clear fitting”. In this case, as in the first embodiment, a guide portion (concave groove 40c and protrusion) is formed by using the sealing means 80 by contact (contact by pressure contact) between the stepped surface 53 and the air chamber side end surface 40b of the bearing 40 together. 55) can be supplemented.

[Modification of Example 3]
In the third embodiment, the shape and the number of the guide groove 40c and the protrusion 55 can be arbitrarily selected. When the minimum pair is used, the guide groove 40c is 180 ° with respect to the groove 40a forming the air passage 70. It is good to arrange | position in the symmetrical position separated. If the circumferential positioning can be ensured by an automatic machine or the like when the bearing 40 is press-fitted, the guide groove 40c and the protrusion 55 may be omitted.

[Reference example]
Next, a reference example to which the present invention is not applied will be described with reference to FIG.
This reference example is an example in the case where an air passage 70 is provided on the outer peripheral surface of the throttle shaft 4 or the inner peripheral surface of the bearing 40, and the air passage 70 is provided on the outer peripheral surface of the throttle shaft 4 as shown in FIG. 5. A concave groove M is formed. After the assembly of the bearing 40 is completed, a seal member S for closing the concave groove M is provided on the air chamber side end surface of the bearing 40.
According to the above configuration, since the bearing 40 is preliminarily assembled to the throttle shaft 4 and then press-fitted into the shaft accommodating portion 24 (large diameter hole portion 52), the seal member S must also be preliminarily assembled. I must. That is, even when the bearing 40 is press-fitted, the seal member S closes the concave groove M, and the air in the air chamber 60 between the oil seal 30 and the bearing 40 flows out through the concave groove M satisfactorily. I can't.

As mentioned above, although the Example of this invention was explained in full detail, the throttle apparatus 1 of this invention can be useful also for the engine with a PCV (blow-by gas reduction apparatus), and also to the engine which is not equipped with a supercharger or PCV. Of course, it is applicable.
In the first to third embodiments, an example in which the present invention is applied to an electronic throttle device in which the throttle valve 3 is rotationally driven by the drive motor 5 has been described, but a normal throttle device, that is, one end of the throttle shaft 4 is described. Instead of the power transmission device and the drive motor 5 provided in the part, the present invention can also be applied to a throttle device in which a lever part mechanically connected to an accelerator pedal via a wire cable is provided.

  DESCRIPTION OF SYMBOLS 1 ... Throttle device, 2 ... Throttle body, 3 ... Throttle valve, 4 ... Throttle shaft, 21 ... Intake passage, 22 ... Passage wall, 24 ... Shaft accommodating part, 30 ... Oil seal, 40 ... Bearing, 40a ... Concave groove ( Air passage), 40b ... End face of bearing on air chamber side (part of sealing means), 53 ... Stepped surface (part of sealing means), 54 ... Projection (part of sealing means), 60 ... Air chamber, 70 ... Aeration path, 80 ... sealing means, 81, 82 ... sealing member (an example of sealing means).

Claims (7)

A throttle body (2) having an intake passage (21) constituting an intake system of the internal combustion engine;
A throttle valve (3) that is rotated by a throttle shaft (4) rotatably supported by the throttle body (2) to open and close the intake passage (21);
A shaft housing portion (24) that is provided in a hole shape through the passage wall (22) of the intake passage (21) with respect to the throttle body (2), and through which the throttle shaft (4) is inserted and held;
An oil seal that is housed and held between the inner peripheral surface of the shaft housing portion (24) on the intake passage side and the outer peripheral surface of the throttle shaft (4) and closes the intake passage side opening of the shaft housing portion (24). (30),
The shaft housing (24) is housed and held by press-fitting between the inner peripheral surface of the anti-intake passage side of the shaft housing (24) and the outer peripheral surface of the throttle shaft (4), and supports the throttle shaft (4) so as to be rotatable. A bearing (40) for closing the opening on the side opposite to the intake passage of the shaft housing (24);
A throttle device (1) comprising:
An air chamber (60) formed between the oil seal (30) and the bearing (40) in the shaft housing (24);
Formed in a part of a bearing press-fitting surface constituted by an inner peripheral surface on the side opposite to the intake passage of the shaft housing portion (24) and an outer peripheral surface of the bearing (40), the air chamber (60) and the bearing ( 40) air passages (70, 40a) communicating with the non-air chamber side;
The bearing (40), which is press-fitted into the shaft housing portion (24) from the side opposite to the intake passage, is press-fitted to a predetermined press-fitting position, whereby the air chamber (60) and the ventilation path (70, 40a). Sealing means (80, 40b · 53, 53 · 81, 53 · 82, 40a · 54) for blocking communication with
The throttle device (1) characterized by comprising. The throttle device (1) according to claim 1,
An air chamber side end surface (40b) of the bearing (40) contacts the shaft housing portion (24), and a positioning stepped surface (53) for regulating a predetermined press-fitting position of the bearing (40). Provided,
The throttle device (1), wherein the sealing means (80) is configured by the air chamber side end surface (40b) and the stepped surface (53) contacting each other. The throttle device (1) according to claim 1,
The shaft housing portion (24) is provided with a stepped surface (53) facing the air chamber side end surface (40b) of the bearing (40),
Between the stepped surface (53) and the air chamber side end surface (40b), seal members (81, 82) fixed to one surface and detachable from the other surface are disposed. Has been
The sealing means (80) is configured such that when the bearing (40) is press-fitted to a predetermined press-fitting position, the seal member (81, 82) seals between the both surfaces (40b, 53). Characteristic throttle device (1). In the throttle device (1) according to any one of claims 1 to 3,
The throttle device (1), wherein the air passage (70) is formed only on the outer peripheral surface of the bearing (40). In the throttle device (1) according to any one of claims 1 to 3,
The throttle device (1), wherein the air passage (70) is formed only on the inner peripheral surface of the shaft housing portion (24) on the side opposite to the intake passage. The throttle device (1) according to claim 1,
The air passage (70) is composed of a concave groove (40a) formed only on the outer peripheral surface of the bearing (40),
On the inner peripheral surface of the shaft housing portion (24) on the side opposite to the intake passage, a protrusion (54) that is inserted only into the air chamber side of the concave groove (40a) is provided.
The sealing means (80) is configured such that when the bearing (40) is press-fitted to a predetermined position, the protrusion (54) fits into the groove (40a) and closes the groove (40a). A throttle device (1) characterized by the above. The throttle device (1) according to claim 6,
A guide groove (40b) extending in the axial direction over the entire length of the bearing (40) is formed on the outer peripheral surface of the bearing (40) at a position different from the concave groove (40a).
A guide projection (55) having an axial length longer than the axial length of the guide groove (40b) and fitted into the guide groove (40b) is formed on the inner peripheral surface of the shaft housing portion (24). A throttle device (1) characterized in that

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