JP2000265861A - Air intake device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air intake device for an internal combustion engine, capable of mounting accessories firmly and accurately in position without play while preventing displacement due to heat onto a throttle body comprising a metallic core molded in a body main body made of resin by means of insert molding. SOLUTION: A throttle shaft 2 having a throttle valve 1 is supported so as to be turned by a throttle body 3 comprising a metallic core 33 molded in a body main body 30 made of resin by means of insert molding. Mounting parts (343, 346, 349 and 356) for mounting accessories (5, 12, 21, 23 and 25) onto a throttle body 3, is formed up out of metals integrally joined to the core 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake device for an internal combustion engine mainly including a throttle body provided in an intake passage of the engine (also referred to simply as an intake device).

[0002]

2. Description of the Related Art There is a conventional intake device in which a throttle body rotatably supporting a throttle shaft having a throttle valve is formed by insert-molding a metal core into a resin body body (for example, an actual device). Fairness 2-41
No. 328). Such an intake device for an internal combustion engine achieves weight reduction and cost reduction by using a resin body for the body, and at the same time, forms the wall surface of the intake passage near the throttle valve with a metal core to form the resin body. By suppressing the thermal contraction of the body, smooth operation of the throttle valve is ensured.

[0003]

In the conventional intake device described above, for example, when an accessory such as a positioning member for positioning the throttle valve in a fully closed position is attached to the throttle body, an attaching portion for attaching the accessory is provided. May be formed of a resin integral with the body body. However, it is difficult to firmly fix the accessory without rattling because the attachment strength is insufficient when the accessory is attached to the resin attachment portion.

[0004] Further, if the mounting portion is made of resin, the mounting position of the accessory is likely to be shifted due to a difference in thermal expansion between the core and the core due to the thermal effect. Therefore, for example, in the case of the positioning member, the fully closed position of the throttle valve cannot be accurately positioned due to a shift in the mounting position of the positioning member. Also, in an electronically controlled air intake system in which the throttle valve is operated by a motor, in order to accurately operate the throttle valve by the motor, attached parts such as a motor and a gear shaft of a gear transmission mechanism rattle on the throttle body. It is necessary to fix without causing displacement or misalignment.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a throttle body formed by insert-molding a metal core into a resin body body. SUMMARY OF THE INVENTION It is an object of the present invention to provide an intake device for an internal combustion engine in which an attached part can be attached firmly without rattling and with good positional accuracy by preventing displacement of the attachment position due to heat.

[0006]

According to a first aspect of the present invention, a throttle shaft having a throttle valve is rotated on a throttle body formed by insert molding a metal core into a resin body body. An intake device for an internal combustion engine that is supported so as to be able to attach an accessory to the throttle body, the attachment portion being formed of a metal integral with the core. With this configuration, the attachment strength of the attachment parts is increased by attaching the attachment parts to the metal attachment part formed integrally with the core of the throttle body as compared with the case where the attachment part is made of resin. The accessory can be firmly attached to the throttle body obtained by insert-molding a metal core into the body of the above-mentioned body without rattling of the accessory. In addition, since the mounting portion is made of metal, it is possible to prevent the mounting position from being displaced due to the thermal influence of the attached parts. Attachment parts can be attached with high positional accuracy.

According to a second aspect of the present invention, the accessory attached to the throttle body is an opening positioning member for positioning the throttle valve at a predetermined opening.
An intake device for an internal combustion engine according to claim 1. With this configuration, the opening positioning member does not rattle on the metal mounting portion of the throttle body, and the opening positioning member is firmly prevented from displacing the mounting position due to thermal influence. It can be mounted with high accuracy. Therefore, the throttle valve can be accurately positioned at the predetermined opening by the opening positioning member.

According to a third aspect of the present invention, an outer peripheral surface of a shaft bearing cylinder portion which is made of metal integral with a core and has a substantially cylindrical shape for supporting a throttle shaft and is covered with a resin portion integral with a body body. 3. A surface having a surface formed thereon.
An intake device for an internal combustion engine according to claim 1. With this configuration, axial contraction of the resin portion due to a difference in thermal expansion between the metal shaft bearing cylinder and the resin portion can be prevented by the uneven surface of the shaft bearing cylinder. This allows, for example,
Thermal expansion of the resin part, which is expected to occur when the substrate for the throttle opening sensor is disposed close to the axial outside of the shaft bearing cylinder, that is, outward in the axial direction of the shaft bearing cylinder Deformation of the substrate due to extension of the substrate can be prevented.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment will be described with reference to the drawings. 1 is a front view of the intake device, and FIG. 2 is a sectional view taken along line II-II of FIG. 1 and 2, a throttle shaft 2 having a throttle valve 1 is rotatably supported on a throttle body 3, and the throttle valve 1 is operated by a forward / reverse rotatable motor 5 such as a stepping motor. This is an electronically controlled intake device. The throttle valve 1 is a butterfly valve that opens and closes the intake passage 4 of the throttle body 3 and is fastened to the throttle shaft 2 by a screw 8.

As shown in FIG. 2, the throttle body 3 is formed by integrally molding a metal core 33 for forming the intake passage 4 with a resin body 30 by insert molding. The body body 30 is manufactured by an injection molding method using, for example, glass fiber reinforced polyamide resin (PA), glass fiber reinforced polybutylene terephthalate resin (PBT), or the like as a resin material. The core 33 is manufactured by die-casting using, for example, aluminum, magnesium or the like as a metal material.
The core 33 is shown in a perspective view in FIG.

The core 33 is formed mainly of a substantially ring-shaped main portion 331 forming the intake passage 4.
In FIG. 3 showing a cross-sectional view taken along the line III-III of FIG.
The cross section of the main part 331 of the core 33 has a substantially vertically long rectangular shape. As shown in an enlarged sectional view of FIG. 6, a seal convex portion 332 having a convex cross-sectional shape is protruded from each outer peripheral portion of the upper and lower end surfaces of the main portion 331. Further, seal concave portions 333 having a concave cross-sectional shape adjacent to the seal convex portions 332 are respectively formed in central portions of both end surfaces of the main portion 331. The upper and lower end surfaces and the outer peripheral surface of the main portion 331 including the seal convex portions 332 and the seal concave portions 333 are formed by resin molding of the body main body 30 (signs and symbols) by insert molding of the core 33 into the body main body 30.
(Attached 301).

The seal convex portion 332 and the seal concave portion 3
33 both exert a sealing action, but here, the sealing action by the sealing projection 332 will be described with reference to FIGS. 7 to 9. 7 shows a normal temperature state, FIG. 8 shows a high temperature state, and FIG. 9 shows a low temperature state. Normally, the linear expansion coefficient μ1 of the resin body 30 and the metal core 3
Comparing with the linear expansion coefficient μ2 of 3, μ1> μ2. For this reason, in the high temperature state (see FIG. 8), the gap C1 (in FIG. 8, exaggerated in FIG. 8) is provided between the outer peripheral surface of the main portion 331 of the core 33 including the sealing convex portion 332 and the resin portion 301 facing the outer peripheral surface. Have been.) However, the seal protrusion 3
Since the inner peripheral surface of 32 and the resin portion 301 facing it are in contact with no gap, air leakage through the gap C1 is prevented.

In a low temperature state (see FIG. 9), the core 3
3 suppresses thermal contraction of the resin portion 301, and a gap C2 between the inner peripheral surface of the seal projection 332 and the resin portion 301 facing the same (exaggerated in FIG. 9). Can be. However, the outer peripheral surface of the main portion 331 of the core 33 including the seal convex portion 332 of the core 33 and the resin portion 301 facing the outer peripheral surface of the main portion 331.
Are in contact with each other without a gap, thereby preventing air leakage through the gap C2.

In FIG. 2, a front shaft bearing cylinder 335 is formed integrally with the core 33 at the front side of the main portion 331 of the core 33. In FIG. 10 which shows a partial cross-sectional view of the front shaft bearing cylinder 335, a convex portion 336 is formed in an annular shape on the outer peripheral surface of the front shaft bearing cylinder 335. Are formed. The outer peripheral surface of the front shaft bearing cylinder 335, that is, the uneven surface 337 is
The body 33 is covered with a resin portion (reference numeral 302) by insert molding of the core 33 into the body 30.

In FIG. 2, a rear shaft bearing cylinder 339 is formed integrally with the core 33 on the rear side of the main portion 331 of the core 33. In FIG. 11 showing a partial cross-sectional view of the rear shaft bearing cylinder 339, a plurality of projections 340 are formed in an annular or arc shape on the outer peripheral surface of the rear shaft bearing cylinder 339.
The projections 340 form an uneven surface 341 on the outer peripheral surface of the rear shaft bearing cylinder 339. The outer peripheral surface of the rear shaft bearing cylindrical portion 339, that is, the uneven surface 341 is formed by inserting the core 33 into the body main body 30 by insert molding.
3).

As shown in FIG. 2, the throttle shaft 2 is rotatably supported by the front shaft bearing cylinder 335 and the rear shaft bearing cylinder 339 via bearings 6 and 7, respectively. For example, the front bearing 6 is a needle bearing (see FIG. 10), and the rear bearing 7 is a ball bearing (see FIG. 11).

As shown in FIG. 10, a substantially cylindrical turning lever 9 is rotatably fitted to the front end of the throttle shaft 2 projecting forward from the front shaft bearing cylinder 335. A substantially disk-shaped fixing lever 10 is fixed by caulking or the like. The rotation lever 9
As shown in FIG. 1, a stopper portion 9b and a stopper piece 9a projecting in the outer diameter direction through an opening groove 10a of the fixed lever 10 are formed. Stopper part 9 of rotating lever 9
b is in contact with the rim of the opening groove 10a in the state shown in FIG. 1 and is rotatable counterclockwise with the fixed lever 10 in this state.

As shown in FIG. 10, a back spring 11A made of a coil spring is fitted between the rotary lever 9 and the throttle body 3 on the front shaft bearing cylinder 335 and the rotary lever 9. Interposed in state. The back spring 11A always urges the rotating lever 9 in the closing direction.

An opener spring 11B composed of a coil spring is interposed between the rotating lever 9 and the fixed lever 10 in a state fitted in a groove 9c of the rotating lever 9. Opener spring 11B
Always urges the fixing lever 10 in the opening direction.

Further, as shown in FIGS. 1 and 2, a front screw mounting portion 343 adjacent to the right side of the front shaft bearing cylinder 335 is provided at the right rear portion of the main portion 331 of the core 33. 33 is made of a single piece of metal. As shown in FIG. 4 in a sectional view taken along the line IV-IV in FIG. 2, the front screw mounting portion 343 is formed of a resin portion (reference numeral 304) of the body main body 30 by insert molding of the core 33 into the body main body 30. Covered. In addition, a screw hole 344 is formed at the front end of the screw mounting portion 343 on the front side. The screw holes 344 are formed on the upper and lower sides of the resin portions 3.
04.

The opener position adjusting screw 12 is screwed into the screw hole 344 of the front screw mounting portion 343. A lock nut 13 is screwed to a lower end of the opener position adjusting screw 12. Lock nut 1
3 is directly in contact with the lower surface of the screw mounting portion 343 on the front side.

As shown in FIG. 1, a stopper piece 9a of the rotating lever 9 can abut on the upper end of the opener position adjusting screw 12. The throttle valve 1 is held at an opener opening position larger by a predetermined amount than a fully closed position (for example, an idle position) by the opener position adjusting screw 12, the rotating lever 9, the fixed lever 10, the back spring 11A and the opener spring 11B. A throttle opener is configured. Opener position adjustment screw 1
Reference numeral 2 corresponds to "an accessory attached to the throttle body 3" according to the present invention, and also corresponds to "an opening positioning member for positioning the throttle valve 1 at a predetermined opening" according to the present invention. The front screw mounting portion 343 corresponds to the “mounting portion for mounting an accessory” in the present invention.

Next, the operation of the throttle opener will be described. As shown in FIG. 1, when the stopper piece 9a of the rotating lever 9 abuts on the opener position adjusting screw 12, the rotating lever 9 is prevented from rotating in the closing direction. At the same time,
In a state where the edge of the opening groove 10a of the fixed lever 10 urged in the opening direction (the counterclockwise direction in FIG. 1; see the direction of the arrow O) by the opener spring 11B abuts on the stopper 9b of the rotating lever 9. , The throttle valve 1 is held at the opener opening position. Thus, by holding the throttle valve 1 at the opener opening position when the motor 5 is turned off, poor engine start due to icing of the throttle valve 1 in a cold region or the like can be prevented, and the engine 5 when the motor 5 fails can be prevented. Driving (evacuation driving in vehicles)
Is made possible.

When the fixed lever 10 is turned in the closing direction (clockwise direction in FIG. 1; see the direction of arrow S in FIG. 1) against the bias of the opener spring 11B at the above-mentioned opener opening position, Stopper 9b of moving lever 9
Then, the edge of the opening groove 10a of the fixed lever 10 moves away from the opening, the throttle valve 1 is closed more than the opener opening position, and finally the fully closed position (for example, the idle position).

When the fixing lever 10 is rotated in the opening direction (counterclockwise direction in FIG. 1; see the direction of arrow O in FIG. 1) against the bias of the back spring 11A in the above-described opener opening position, the fixing lever 10 is fixed. While the edge of the opening groove 10a of the lever 10 is kept in contact with the stopper 9b of the rotating lever 9, the stopper piece 9a of the rotating lever 9 moves away from the opener position adjusting screw 12 and the throttle valve 1 Are opened more than the opener opening position.

Further, as shown in FIG. 11, an oil seal 14 in which the throttle shaft 2 is fitted following the bearing 7 is incorporated in the rear shaft bearing cylinder 339. The oil seal 14 maintains airtightness between the throttle shaft 2 and the rear shaft bearing cylinder 339.

Further, the throttle shaft 2 has
A rotor 15 for a throttle opening sensor which is adjacent to the outside of the oil seal 14 and located in the rear shaft bearing cylinder 339 is attached. The rotor 15 is provided with a brush 16 that comes into contact with a conductive portion (not shown) of a throttle opening sensor substrate 17 disposed on the rear side (upper side in FIG. 11) of the throttle body 3. The rotor 15 having the brush 16 and the substrate 17 constitute a throttle opening sensor. The throttle opening sensor detects the rotation angle, that is, the opening of the throttle valve 1 from the position of the brush 16 with respect to the substrate 17, and outputs a detection signal to an engine control computer (not shown).

As shown in FIG. 2, a rear end of the throttle shaft 2 is provided with a substrate 1 for a throttle opening sensor.
7, a throttle gear 18 is fastened to the rear end of the throttle shaft 2 by a nut 18A. Further, a substrate housing portion 305 which is substantially flange-shaped and continuous is formed integrally with the resin portion 303 of the body main body 30 which covers the rear shaft bearing cylinder portion 339. The substrate 17 is accommodated in the substrate accommodation portion 305 in a fixed state. It should be noted that the throttle gear 18 provided in the substrate accommodating portion 305, a driving gear 20 and an intermediate gear 22 described later.
The board 17 is disposed at a position close to the opening end face of the resin portion 303 in order to prevent chips and dust from entering the detection portion of the throttle opening sensor.

In FIG. 2, the main part 331 of the core 33 is shown.
A substantially cylindrical motor mounting portion 346 that penetrates in the front-rear direction is formed of a metal integral with the core 33 at the right rear portion. The motor mounting portion 346 is attached to the body 30.
The core 33 is covered with a resin portion (reference numeral 306) of the body body 30 by insert molding. A bottomed screw hole 347 is provided on the rear end face of the motor mounting portion 346.
(See FIG. 13). In addition, the screw hole 347
Is covered by a resin portion 306 on the rear side of the motor mounting portion 346.

In the motor mounting portion 346, the motor 5 is inserted with the output shaft 5a facing rearward and the mounting screw 19 (two points in FIG. 2) inserted through a through hole (not shown) of the mounting flange 5b. It is attached by screwing the chain line 19) into the screw hole 347. A drive gear 20 is fixed to the output shaft 5a of the motor 5. In addition, the motor 5 is equivalent to the "attachment part attached to the throttle body 3" in the present invention, and the motor attachment part 346 is equivalent to the "attachment part for attaching the accessory part" in the present invention.

In FIG. 2, the main part 331 of the core 33 is shown.
In the right rear portion, a substantially bottomed cylindrical shaft mounting portion 349 located substantially at the middle between the rear shaft bearing cylinder portion 339 and the motor mounting portion 346 is formed of metal integral with the core 33. The outer peripheral surface of the shaft attachment portion 349 is covered with a resin portion (reference numeral 307) of the body main body 30 by insert molding of the core 33 into the body main body 30. The shaft mounting portion 349 has a bottomed press-fit hole 350 (see FIG. 13).
The gear shaft 21 is attached to the press-fitting hole 350 by press-fitting. Note that the gear shaft 21 corresponds to “an accessory attached to the throttle body 3” in the present invention, and the shaft attachment portion 349 corresponds to “an attachment portion for attaching an accessory” in the present invention.

The gear shaft 21 has an intermediate gear 22
Are rotatably supported. The intermediate gear 22 has a front small gear portion 22a and a rear large gear portion 22b. The small gear portion 22a is meshed with the throttle gear 18, and the large gear portion 22b is meshed with the drive gear 20. Thus, the drive of the motor 5 is transmitted to the throttle shaft 2 via the gear transmission mechanism including the drive gear 20, the intermediate gear 22, and the throttle gear 18, so that the throttle valve 1 is opened and closed.

In FIG. 2, a fully closed position adjusting screw 23 is disposed on the left side of the throttle gear 18. In FIG. 12, which shows a cross-sectional view around the mounting portion of the fully closed position adjusting screw 23, the shaft bearing cylinder 3 on the rear side of the core 33 is shown.
On the left side of 39, a rear screw mounting portion 352 is formed of metal integral with the core 33. The rear screw mounting portion 352 is formed by insert molding of the core 33 into the body main body 30 by a resin portion (reference numeral 308) of the body main body 30.
Is attached). Rear screw mount 352
Is formed with a screw hole 353 at the tip end.

The fully closed position adjusting screw 23 is screwed into a screw hole 353 of the rear screw mounting portion 352. A lock nut 2 is provided at the outer end of the fully closed position adjusting screw 23.
4 is screwed. The lock nut 24 is in direct contact with the outer side surface of the screw mounting portion 352 on the rear side.

At the inner end of the fully closed position adjusting screw 23,
An abutting portion (not shown) of the throttle gear 18 can abut. The fully closed position adjusting screw 23 is connected to the throttle gear 18.
In the state where the abutment portion abuts, the rotation of the throttle gear 18 in the closing direction is prevented, so that the throttle valve 1 is set to a fully closed position (for example, an idle position) in which the throttle valve 1 is closed from the opener opening position. You. The fully closed position adjustment screw 2
Reference numeral 3 corresponds to "an accessory attached to the throttle body 3" according to the present invention, and also corresponds to "an opening degree positioning member for positioning the throttle valve 1 at a predetermined opening degree" according to the present invention. The rear screw mounting portion 352 corresponds to the “mounting portion for mounting an accessory” in the present invention.

As shown in FIG. 2, a resin cover 32 for covering the throttle gear 18, the drive gear 20, the intermediate gear 22, the fully closed position adjusting screw 23, and the like is provided at the open end of the substrate accommodating portion 305. Are attached by welding. FIG. 14 is a partial cross-sectional view illustrating a welded portion between the substrate housing portion 305 and the cover 32.

As shown in FIGS. 2 and 3, on the left side of the main portion 331 of the core 33, a substantially cup-shaped wall portion 356 forming a hot water chamber 355 having an open left end surface is integrated with the core 33. It is made of metal. The outer peripheral surface of the wall portion 356 is formed of a resin portion (reference numeral 309) of the body body 30 by insert molding of the core 33 into the body body 30.
Covered with.

As shown in FIG. 2, a bottomed screw hole 357 is formed in the open end surface of the wall portion 356. The hot water pipe connection fitting 25 is attached to the wall portion 356 by screwing a set screw 26 passed through a through hole (not shown) of the attachment flange 25 a into the screw hole 357. The hot water pipe connection fitting 25 has an inlet pipe 2
5b and an outlet pipe 25c are provided. By connecting a hot water circulation pipe using engine cooling water (not shown) to the inlet pipe 25b and the outlet pipe 25c, hot water circulates in the hot water chamber 355 and the throttle body 3
Since the whole is heated, icing of the throttle valve 1 is prevented. The connection fitting 25 for hot water piping corresponds to the "attachment part attached to the throttle body 3" in the present invention, and the wall 356 corresponds to the "attachment part for attaching the accessory part" in the present invention.

As shown in FIGS. 1 and 2, at the lower end of the main portion 331 of the core 33, a mounting flange 359 projecting right forward, right rear and left rear is formed of metal integral with the core 33. ing. The mounting flange 359 is
The body 33 is covered with a resin portion (reference numeral 310) by insert molding the core 33 into the body 30. The mounting flange 359 is formed with a mounting hole 360 that penetrates the resin portions 310 on both the upper and lower sides.

As shown in FIG. 1, a power receiving connector 312 is formed at the upper right portion of the body 30 by a resin integral with the body 30. In FIG. 5 showing a cross-sectional view taken along line VV of FIG. 1, a power receiving connector 312 surrounds a terminal 27 electrically connected to the motor 5. A power supply connector of an engine control computer (not shown) is connected to the power reception connector 312. Thus, the rotation of the motor 5 is controlled by inputting a signal from the engine control computer to the motor 5 through the terminal 27.

According to the intake device of the internal combustion engine described above, the attached motor 5 is attached to the motor attachment portion 346 which is a metal attachment portion formed integrally with the core 33 of the throttle body 3. Also, throttle body 3
The gear shaft 2 attached to a shaft mounting portion 349 which is a metal mounting portion formed integrally with the core 33 of FIG.
1 is attached.

Therefore, as described above, each of the metal attachment portions (346, 349) formed integrally with the core 33 of the throttle body 3 has its own accessory (5, 2).
By mounting 1), the mounting strength of each accessory is increased as compared with the case where each of the mounting portions is made of resin, and a throttle body formed by insert-molding a metal core 33 into the resin body body 30. 3, the attached parts can be firmly attached without rattling. Further, since the mounting portions (346, 349) are made of metal, it is possible to prevent the mounting position from being displaced due to the thermal influence of the accessory parts (5, 21). Each of the accessory parts (5, 21) can be attached with high positional accuracy to the throttle body 3 formed by insert molding the core 33 made of steel.
Thus, the driving force of the motor 5 can be reliably transmitted to the throttle shaft 2, and the operation of the throttle valve 1 by the motor 5 can be performed accurately.

Further, an opener position adjusting screw 12 which is an accessory and an opening positioning member is attached to a front screw attaching portion 343 which is a metallic attaching portion formed integrally with the core 33 of the throttle body 3. I have. Further, a rear screw mounting portion 352 which is a metal mounting portion formed integrally with the core 33 of the throttle body 3.
A fully-closed position adjusting screw 23, which is an accessory part and an opening position determining member, is attached to the second position.

Therefore, the opening position determining members (12, 23) of the accessory parts are firmly attached to the metal attachment portions (343, 352) of the throttle body 3 without rattling and the attachment positions of the attachment positions due to the influence of heat are firmly determined. Positioning can be prevented and positional accuracy can be improved. For this reason,
The throttle valve 1 can be accurately positioned at each predetermined opening by the opening positioning members (12, 23).

Further, a fitting 25 for hot water piping, which is an accessory, is attached to a wall portion 356 which is a metal attachment portion formed integrally with the core 33 of the throttle body 3. Therefore, the attachment part (25) can be firmly attached to the metal attachment part (346) of the throttle body 3 without rattling, and can be attached with good positional accuracy by preventing displacement of the attachment position due to heat. . For this reason, it is possible to prevent liquid leakage that is expected to occur due to the displacement of the hot water pipe connection fitting 25.

In order to support the throttle shaft 2, the shaft bearing cylinder portions 335, 339 are formed of metal integral with the core 33 and have a substantially cylindrical shape and are covered with resin portions 302, 303 integral with the body body 30. Uneven surfaces 337 and 341 are formed on the outer peripheral surface. Therefore, the metal shaft bearing cylinder parts 335, 339 and the resin parts 302, 30
3, the shrinkage in the axial direction of the resin parts 302, 303 due to the difference in thermal expansion from the uneven surface 33 of the shaft bearing cylinder parts 335, 339.
7, 341 can be prevented.

Thus, for example, when the substrate 17 for the throttle opening sensor is disposed close to the rear side of the shaft bearing cylinder 339 in the axial direction, the resin portion 303 is expected to occur. This prevents the substrate 17 from being deformed due to thermal expansion of the shaft bearing cylinder 339 in the axially outward direction. In particular, by forming an uneven surface 341 (see FIG. 11) by a plurality of convex portions 340 on the outer peripheral surface of the rear shaft bearing cylinder portion 339, deformation of the substrate 17 due to thermal expansion of the resin portion 303 can be effectively performed. Can be prevented.

The present invention is not limited to the above embodiment, but can be modified without departing from the spirit of the present invention. For example, the present invention can be applied not only to an electronically controlled air intake device but also to a mechanically air intake device. In addition, each of the metal attachment portions formed integrally with the core 33 is formed simultaneously and integrally with the core 33 by cold forging, and then a necessary portion is cut or the core 33 is formed by cutting. Alternatively, it can be formed by a method in which the cores 33 are separately formed and then integrated by welding or the like. Further, the number, shape, and the like of the metal attachment portions are not limited to those in the above-described embodiment, and are appropriately selected. Also, the shaft bearing cylinder 3
The shapes of the concave and convex surfaces 337 and 341 on the outer peripheral surfaces of 35 and 339 are also appropriately selected.

[0049]

According to the intake device for an internal combustion engine of the present invention,
For the throttle body made by insert-molding a metal core to the resin body body, the attached parts are firmly attached without rattling and prevented from misalignment of the attachment position due to heat, with good positional accuracy be able to.

[Brief description of the drawings]

FIG. 1 is a front view of an intake device.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 1;

FIG. 6 is a partial sectional view of a seal portion.

FIG. 7 is an explanatory diagram showing a normal temperature state of a seal portion.

FIG. 8 is an explanatory view showing a high temperature state of a seal portion.

FIG. 9 is an explanatory diagram showing a low-temperature state of a seal portion.

FIG. 10 is a partial sectional view of a front shaft bearing cylinder.

FIG. 11 is a partial sectional view of a rear shaft bearing cylinder.

FIG. 12 is a cross-sectional view showing the vicinity of a mounting portion of a fully closed position adjusting screw 23;

FIG. 13 is an external perspective view of a core.

FIG. 14 is a partial sectional view of a joint portion of a cover.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Throttle valve 2 Throttle shaft 3 Throttle body 5 Motor (accessory) 12 Opener position adjustment screw (opening positioning member of accessory) 17 Substrate for throttle opening sensor 21 Gear shaft (accessory) 23 Fully closed position adjustment screw (Opening positioning member for accessory parts) 25 Fitting for hot water piping (accessory parts) 30 Body body 301-304, 306-310 Resin part 33 Core 335, 339 Shaft bearing cylinder part 337, 341 Uneven surface 343 Front side screw attachment Part (mounting part) 346 Motor mounting part (mounting part) 349 Shaft mounting part (mounting part) 352 Front screw mounting part (mounting part) 356 Wall part (mounting part)

Claims (3)

[Claims] 1. An intake device for an internal combustion engine, wherein a throttle shaft having a throttle valve is rotatably supported on a throttle body obtained by insert-molding a metal core into a resin body body. An intake device for an internal combustion engine, wherein a mounting portion for mounting an accessory is formed of a metal integral with the core. 2. The intake device for an internal combustion engine according to claim 1, wherein the accessory attached to the throttle body is an opening positioning member for positioning the throttle valve at a predetermined opening. 3. An outer peripheral surface of a shaft bearing cylinder portion formed of a metal integral with a core and formed in a substantially cylindrical shape for supporting a throttle shaft and covered with a resin portion integral with the body body. Item 3. An intake device for an internal combustion engine according to item 1 or 2.