GB2393218A

GB2393218A - Supporting the drive shaft of a variable flow control system, eg of a variable air intake system for an i.c. engine

Info

Publication number: GB2393218A
Application number: GB0316443A
Authority: GB
Inventors: Tetsuji Yamanaka; Takashi Chaya; Masao Ino; Toshio Hayashi; Taisuke Murata
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2002-07-29
Filing date: 2003-07-14
Publication date: 2004-03-24
Anticipated expiration: 2023-07-14
Also published as: GB0316443D0; JP2004124933A; JP3838217B2; GB2393218B

Abstract

Each intake air passage 13 is provided with a valve member 30, eg of polyamide resin, mounted on a rotatable shaft 40, eg of iron. The shaft 40 is supported in an end bushing 41 and intermediate bearing guides 42 in the manifold 10. At the opposite end from the bushing 41 the shaft is driven by actuator 50 via driving gear 60, eg of resin, mounted on the end of the shaft. A guide member 70 is provided between the actuator 50 and the driving gear 60 with an outer wall 73a of the guide member 70 contacting an inner wall 14a of a receiving hole 14 in the manifold 10. A support member 74 of the guide member 70 is in sliding contact with a the inner wall 64a of a bore 64 in the driving gear 60. An outer wall 71a of the guide member 70 contacts an inner wall 51a of the actuator housing 51. A seal 65 may be provided between beaten the manifold 10 and driving gear 60. In a modification, fig.4, the support member 74 of figs. 2,3 is replaced by a support member 55 integral with the actuator 50. A sliding collar (66, fig.5) may be mounted on the support member 55. A seal 65 may be provided between beaten the manifold 10 and driving gear 60.

Description

i 239321 8

VARIABLE FLOW CONTROL SYSTEM

The present invention relates to a variable flow control system, in particular, although not exclusively, a variable intake 5 system of an internal combustion engine.

Conventionally, a variable flow control system is used in various machines to variably control fluid flow in the machines. For instance, in an internal combustion engine, it is used as a variable intake system that variably sets the 10 length of an intake air passage in accordance with the engine speed to thereby improve an engine torque. The length of the intake air passage is increased when the engine speed is low, and is decreased when the engine speed is high, thus improving the torque regardless of the engine speed.

15 In the above variable flow control system, that is, variable intake system, the intake air passage is branched off into passages of different lengths, for instance, which are opened and closed by a valve member to change the entire length and sectional area of the intake air passage. As the valve 20 member for opening and closing the intake air passage of the variable intake system, a butterfly valve such as disclosed in DE29916333U1 is used.

As shown in Fig. 6, a variable intake system has an intake manifold 100 which forms an intake air passage. The intake 25 manifold 100 is branched to form intake air passages according to the number of engine cylinders. In the intake air passage a valve member is assembled. The valve member is driven by

an actuator 102 having a motor 101 for instance. The end portion of a shaft 103 supporting the valve member is inserted in a driving gear 104 which transmits the driving force from the actuator 102. The driving gear 104 in which the shaft 103 5 is inserted is rotatably supported on a bearing 105 in the intake manifold 100.

In recent years, to reduce weight and to improve heat insulating properties and freedom of design, most of such members constituting the variable intake system as the intake 10 manifold 100 end the driving gear 104 are formed of for instance a polyamide resin. The bearing 105 supporting the driving gear 104 is a metal bearing, which is adopted to decrease the sliding torque and to improve the bearing accuracy and positioning accuracy of the driving gear 104. Furthermore, 15 to prevent axial movement of the driving gear 104, the bearing 105 must be secured on the intake manifold 100. When the intake manifold is formed of a metal like the conventional type, the bearing for instance is pressed and secured in the intake manifold. 20 However, when the metal bearing 105 is pressed in the intake manifold 100 formed of resin as describe above, a tightening force will decrease with time due to the creep of the resin, making it hard to keep the bearing 105 in a pressed-in state. In such a case, the bearing 105 will become 25 loose in the intake manifold 100, coming off the intake manifold 100 when added with an axial force. Furthermore, if the bearing 105 becomes loose in the intake manifold 100,

accuracy of the bearing position of the driving gear 104 in relation to the shaft 103 will be lowered.

Accordingly, preferred embodiments of the present invention seek to provide a variable flow control system which is capable of 5 supporting a driving shaft member without using a bearing and has a high accuracy in the position of members to be mounted.

According to an emxxhent of a variable flow control system of the present invention, a support member which supports a driving shaft member through a driving gear slides on the inner wall 10 of a bore section of the driving gear. Thus the driving gear is rotatably supported by the support member on the inner peripheral side. Therefore, the driving gear is supported without using a bearing, thereby improving the positioning accuracy of the bearing section even when a surrounding member 15' formed of resin is used. Furthermore, the support member, sliding on the inner wall of the bore section, insures its being coaxial with the driving shaft. Therefore, movement of the driving gear is restrained by the support member, to thereby enable enhancing the positioning accuracy of the bearing 20 section. Preferably, a guide member is assembled between a driving gear and an actuator. The outer wall of the guide member contacts the inner wall of the actuator. Thus the contact between the outer wall of the guide member and the inner wall 25 of the actuator positions the guide member and the actuator, thereby improving the positioning accuracy of the actuator.

Preferably, a support member is projecting from the guide -3-

member toward the driving gear. Therefore, positioning the guide member positions the support member which supports the driving shaft member through the driving gear, thereby enabling enhancing the positioning accuracy of the bearing 5 section. Preferably, the variable flow control system is used as a variable intake system for an internal combustion engine.

A guide member has a fitting section for fitting to an intake manifold. The outer wall of the fitting section contacts the 10 inner wall of the intake manifold, to thereby position the guide member in relation to the intake manifold. With the guide member thus positioned in relation to the intake manifold, the actuator is positioned. That is, the intake manifold and the actuator are positioned through the guide member, thereby 15 enabling an improvement in the positioning accuracy of the actuator relative to the intake manifold. Furthermore, by forming the support member on the guide member for instance, the bearing section of the driving gear will also be positioned when the intake manifold and the guide member are positioned.

20 Preferably, a support member is formed on an actuator.

Therefore a driving gear is supported directly by the actuator, thereby enabling enhancing the positioning accuracy of the bearing section of the driving gear.

Preferably, a sliding member is provided between a 25 support member and a driving gear. The sliding member is secured on either one of the support member and the driving gear and rotatably slides on the other. Thus the support -4-

member for instance is formed of a strength-oriented material; the sliding member can be formed of a wear resistance-oriented material. Therefore, it is possible to insure both the strength and sliding capability of the bearing section.

Other objects, features and characteristics of the present invention will become more apparent from the following detailed description made, by way of example only, with reference

to the accompanying drawings, in which: 10 Fig. 1 is a schematic view showing an engine to which a variable flow control system according to a first embodiment of the present invention is applied as a variable intake system; Fig. 2 is a schematic sectional view of the variable flow 15 control system according to the first embodiment of the present invention, showing a valve member mounted in an intake air passage, and an actuator; Fig. 3 is a schematic sectional view of the variable flow control system according to the first embodiment of the present 20 invention, showing the surrounding of an actuator and a driving gear; Fig. 4 is a schematic view showing a variable flow control system according to a second embodiment of the present invention, or a sectional view showing the surrounding of an 25 actuator and a driving gear; Fig. 5 is a schematic sectional view of a variable flow control system according to a third embodiment of the present

invention, showing the surrounding of en actuator and a driving gear; and Fig. 6 is a schematic sectional view of a prior art conventional

variable flow control system, showing the surrounding of an 5 actuator. A plurality of embodiments embodying a variable flow control system of the present invention as a variable intake system will be described, by way of example only, with reference to 10 the accompanying drawings.

FIRST EMBODIMENT

Referring first to Fig. 1, a variable intake system 1 is mounted in the intake system of an engine. The variable intake system 1 is provided with an intake manifold 10. The intake 15 manifold 10 connects an air connector 11 with cylinders of an engine body 20.

Intake air drawn in through an intake duct (not shown) flows into the air connector 11 via an air cleaner and a throttle valve which are not shown, and then is distributed 20 into the intake manifold 10 through a surge tank lea. The intake manifold 10 is branched off in accordance with the number of cylinders of the engine body 20 from the surge tank lea on the outlet side of the air connector 11 which is connected to the outlet side of the unillustrated throttle 25 valve. The intake manifold 10 thus branched off according to the number of cylinders is further branched off into an intake air passage 12 for low-speed rotation and an intake air passage -6-

13 for high-speed rotation. The intake manifold 10 is unitarily formed of polyamide resin.

The overall length of the intake air passage 12 for low-speed rotation up to the engine body 20 is formed longer 5 than the intake air passage 13 for high-speed rotation. The intake air passage 12 for low-speed rotation and the intake air passage 13 for high-speed rotation thus branched off meet again on the downstream side of the intake air stream, that is, on the engine body 20 side. In the intake air passage 13 10 for high-speed rotation, a valve member 30 is provided to change the sectional area of the passage by closing and opening the intake air passage 13. When the valve member 30 closes the intake air passage 13, the intake air is supplied into the engine body 20 through the intake air passage 12 for low-speed 15 rotation. On the other hand, when the valve member 30 opens the intake air passage 13, the intake air is supplied into the engine body 20 through the intake air passage 13 for high-speed rotation which has a less flow resistance. That is, thus changing the sectional area of the intake air passage 13 20 changes the flow rate of the intake air flowing in the intake air passage 13, thereby changing the overall length of the intake air passage in which the intake air is flowing.

As shown in Fig. 2, the intake air passage 13 for high-speed rotation is branched off in accordance with the 25 number of cylinders of the engine body 20; in each of the intake air passages 13 the valve member 30 is provided. The valve member 30 is rotatable on the center of a shaft 40 as a driving -7-

shaft member. The shaft 40 is formed of a metal, such as iron, having a polygonal cross section perpendicular to the axis of the shaft. On the shaft 40, the valve member 30 having a blade section 31 and a cylinder section 32 is assembled. The shaft 5 40 is inserted through the cylinder section 32 of the valve member 30. In the valve member 30, the blade section 31 and the cylinder section 32 are formed unitarily of a polyamide resin for instance. The valve member 30 is provided with a shaft hole 33 through which the shaft 40 is inserted. The 10 cross- section of the shaft hole 33 is formed in about the same shape as the polygonal cross- section of the shaft 40.

Therefore, when the shaft 40 is inserted in the shaft hole 33, relative rotation between the shaft 40 and the valve member 30 is limited.

15 One end portion of the shaft 40 is rotatably supported by a bushing 41 in the intake manifold 10. The intermediate portion of the shaft 40 is rotatably supported through bearing guides 42 in the intake manifold 10 in which the intake air passages 13 are formed.

20 On the other end portion of the shaft 40 not supported on a bushing, an actuator 50 is mounted to drive the valve member 30. The actuator 50, as shown in Fig. 3, has a housing 51 formed of a polyamide resin, and a motor 52. The motor 52 is connected to an ECU not shown. Intermittently supplying 25 power to the motor 52 by the ECU controls the operation of the valve member 30. The driving force of the motor 52 is transmitted to the shaft 40 through a driving gear 60 mounted -8-

on the end portion of the shaft40 on which no bushing is mounted The actuator 50 is fastened by screws 53 on the intake manifold.

The driving gear 60 has a teeth section 61 and a cylinder section 62. The teeth section 61 and the cylinder section 62 5 are unitarily formed of, for instance, polyamide resin. The teeth section 61 can mesh with a pinion mounted (not shown) in the motor 52. The cylinder section 62 is formed to project from the teeth section 61 toward the intake manifold 10 side and has an insertion hole 63 into which the shaft 40 is inserted 10 to the inner peripheral side. The insertion hole 63, like the shaft hole 33, is formed in about the same shape as the polygonal cross section of the shaft 40. Therefore, inserting the shaft 40 into the insertion hole 63 restricts relative rotation between the driving gear 60 and the shaft 40. In the 15 end portion on the actuator 50 side of the driving gear 60, a bore section 64 is formed. The bore section 64 is recessed toward the intake manifold 10 side from the end face 60a on the actuator 50 side of the driving gear 60.

Between the driving gear 60 and the actuator 50, a guide 20 member 70 is located. The guide member 70 is formed of, for instance, polyamide resin. The guide member 70 is formed in a shape of a bottomed cylinder having a cylinder section 71 and a bottom section 72. At the open end of the cylinder section 71, a fitting section 73 is formed. The fitting 25 section 73 is formed to project radially outwardly from the cylinder section 71, so that it may be fitted in a fitting hole 14 formed in the intake manifold 10. An outer wall 73a formed _9_

on the radially outer side of the fitting section 73 is in contact with an inner wall 14a of the fitting hole 14.

Therefore, the guide member 70 is positioned in the intake manifold 10 by fitting the fitting section 73 in the fitting 5 hole 14. A seal member 54 is located between the fitting section 73 and the actuator 50. With the actuator 50 mounted on the intake manifold 10, the seal member 54 is sandwiched between the housing 51 of the actuator 50 and the intake manifold 10. The seal member 54 therefore can prevent entry 10 of foreign substances into the driving gear side from between the housing 51 and the intake manifold 10.

On the bottom section 72 of the guide member 70, a support member 74 is formed. The support member 74 is formed to project from the bottom section 72 of the guide member 70 toward 15 the driving gear 60. The outside diameter of support member 74 is about the same as the inside diameter of the bore section 64 formed in the driving gear 60. Therefore, the support member 74 inserted in the bore section 64 can slide on the inner wall 64a of the bore section 64. The axial length of the 20 support member 74 is set in accordance with, for instance, the inside diameter of the bore section 64 or a distance from the bottom section 72 to the driving gear 60. Since the support member 74 slides on the inner wall 64a of the bore section 64, the driving gear 60 is rotatably supported on the guide member 25 70.

The cylinder section 71, the bottom section 72 and the fitting section 73 which constitute the guide member 70, and -1 0-

the support member 74 are unitarily formed of resin by using one molding tool. Thus a dimensional error which is likely to occur in molding the guide member 70 decreases. The fitting section 73 of the guide member 70 and the support member 74 5 are coaxially formed. Therefore, positioning the guide member 70 in relation to the intake manifold 10 positions the support member 74. Furthermore the end portion of the shaft 40which is supported on the guide member70 through the driving gear 60 is positioned on the same axis as the support member 10 74.

The outside diameter of the cylinder section 71 of the guide member 70 is about the same as the inside diameter of the housing 51 of the actuator 50. Therefore the outer wall 71a of the cylinder section 71 of the guide member 70 contacts 15 the inner wall 51a of the housing 51 of the actuator 50, to thereby position actuator 50 by the guide member 70. Since the guide member 70 is positioned on the intake manifold 10, the actuator 50 is positioned on the intake manifold 10 through the guide member 70 by mounting the housing 51 of the actuator 20 50 on the outer peripheral side of the guide member 70.

Between the intake manifold 10 and the driving gear 60, a seal member 65 is assembled. The seal member 65 is formed of flexible rubber, which is in flexible contact with the outer periphery of the cylinder section 62 of the driving gear. The 25 seal member 65, therefore, prevents intake air leakage from the intake air passage 13 to the actuator 50 side. The seal member 65 further prevents the entry of water included in the -1 1-

intake air into the actuator 50 side.

Next, the assembling of the variable intake system 1 of the abovedescribed construction will be described.

The driving gear 60, the seal member 65, and the guide 5 member 70 are assembled. The seal member 65 is assembled on the outer peripheral side of the cylinder section 62 of the driving gear 60. The support member 74 formed unitarily with the guide member 70 is inserted in the bore section 64 of the driving gear 60. Thus the driving gear 60, the seal member 10 65, and the guide member 70 are assembled as one unit. The fitting section 73 of the guide member 70 is fitted in the fitting hole 14 of the intake manifold 10, thereby positioning the guide member 70 on the intake manifold 10. With the guide member 70 positioned on the intake manifold 10, the support 15 member 74 is positioned. At this time, the shaft 40 is inserted into the insertion hole 63 of the driving gear 60, and the seal member 65 is set between the cylinder section 62 of the driving gear 60 and the intake manifold 10.

Upon completing the assembling of the guide member 70 to 20 the intake manifold 10, the actuator 50 is assembled. The housing 51 of the actuator 50 is guided by the outer wall 71a of the cylinder section 71 of the guide member 70, thus being assembled to the intake manifold 10. The actuator 50 is positioned in relation to the intake manifold 10. At this time, 25 the seal member 54 is assembled between the guide member 70 and the intake manifold 10 and the actuator 50. The actuator 50 is secured by the screws 53 to the intake manifold 10.

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The assembling of the intake manifold 10 and the actuator 50 which constitute the variable intake system 1 is carried out by the following procedure.

In the first embodiment of the present invention 5 described above, the fitting section 73 of the guide member 70 is fitted in the fitting hole 14 of the intake manifold 10, thereby positioning the guide member 70 in relation to the intake manifold 10. With the guide member 70 thus positioned, the support member 74 which is formed unitarily with the guide 10 member 70 and supports the driving gear 60 is positioned.

Furthermore, with the actuator 50 assembled on the outer periphery side of the guide member 70, the guide member 70 and the actuator 50 are positioned. That is, the driving gear 60 and the actuator 50 are positioned on the intake manifold 10 15 through the guide member 70. Since the guide member 70 is unitarily formed of resin, the coaxial arrangement of the fitting section 73, the cylinder section 71 and the support member 74 of the guide member 70 can easily be achieved. It is, therefore, possible to improve the positioning accuracy 20 of the driving gear 60 and the actuator 50 in relation to the intake manifold 10. Therefore, the sliding resistance of the driving gear 60 decreases, so that there is no need to support the driving gear 60 by a bearing on the outer periphery side.

Furthermore, after the assembling of the guide member 70 on 25 the intake manifold 10, the actuator 50 can be assembled to the intake manifold 10 by using the guide member 70 as a guide.

Therefore it is also possible to easily position the actuator -13

50 in relation to the intake manifold 10.

In the embodiment, the support member 74 slides on the inner wall 64a of the bore section 64 of the driving gear 60.

Therefore, the axial and radial movement of the shaft 40 and 5 the driving gear 60 is restricted by the support member 74, thereby preventing the movement of the shaft 40 and the driving gear 60 and improving the positioning accuracy of the shaft 40 and the driving gear 60.

SECOND EMBODIMENT

10 A variable intake system according to a second embodiment of the present invention is shown in Fig. 4.

In the second embodiment, a support member 55 is formed on the actuator 50. The support member 55 is formed to project from the housing 51 of the actuator 50 toward the intake 15 manifold 10. The support member 55 is formed unitarily of for instance polyamide resin with the housing 51. Accordingly the guide member may be disused.

When the guide member is disused, the actuator 50 and the support member 55 formed on the actuator 50 cannot be 20 positioned by means of the guide member. However, since the intake manifold 10 is formed of resin, the shape of the intake manifold 10 can beset with ease. Besides, the intake manifold 10 has a high accuracy in shape. As shown in Fig. 4, a holding section 15 is formed for mounting the actuator 50 on the intake 25 manifold 10. The housing 51 of the intake manifold 10 has a flange section 56 which is formed to project radially outward.

The flange section 56 is assembled in the holding section 15.

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The outer wall 56a on the radially outside of the flange section 56 is in contact with the inner wall 15a of the holding section IS, thus positioning the actuator 50. With the actuator 50 positioned on the intake manifold 10, the support member 55 5 which is formed unitary with the housing 51 is also positioned, to thereby improve the positioning accuracy of the bearing section of the driving gear 60.

In the second embodiment, the guide member may be used for positioning the actuator, and furthermore may be so 10 constructed as to support the driving gear by a support member formed on the actuator. In this case also, the actuator is positioned by means of the guide member. With the actuator positioned, the support member formed unitarily with the actuator is also positioned. Consequently, it is possible to 15 enhance the positioning accuracy of the bearing section of the driving gear.

THIRD EMBODIMEnT In a third embodiment, as shown in Fig. 5, a sliding collar 66 is mounted as a sliding member on the support member 20 55. The sliding collar 66 is mounted by for instance pressing onto the support member 55. The outer peripheral wall of the sliding collar 66 slides on the inner wall 64a of the bore sectioned of the driving gear 60. That is, the sliding collar 65 is secured on the support member 55 to rotatably slide with 25 the driving gear 60.

In this embodiment, the sliding collar 66 is assembled between the support member 55 and the driving gear 60. It is, -15

therefore, possible to form the support member 55 of a high-strength material, end the sliding collar 66 ofa material having high wear resistance. Therefore, the strength of the support member can be enhanced and also a sliding quality in 5 the bearing section can be improved.

The sliding collar 66 may be secured to the bore section 64 of the driving gear 60. In this case, the support member 55 slides on the inner peripheral wall of the sliding collar 66. 10 Furthermore, the sliding collared described in the third embodiment may be applied to the variable intake system described in the first embodiment.

The present invention should not be limited to the disclosed embodiments, but may be implemented in many other 15 ways without departing from the spirit of the invention. For instance, the flow control valve may be used in various machines in which fluid flow is controlled.

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Claims

1. A variable flow control system, comprising: a valve member which rotates on a center of a driving 5 shaft member, changing a sectional area of a fluid passage; an actuator which actuates the valve member to adjust a flow of the fluid flowing in the fluid passage; a driving gear mounted on an end portion on an actuator side of the driving shaft member, and having a bore section 10 coaxially with the driving shaft member in the end portion on the actuator side, to thereby transmit a driving force from the actuator to the driving shaft member; and a support member which rotatably supports the end portion of the driving shaft member through the driving gear, sliding 15 on an inner wall of the bore section of the driving gear.

2. A variable flow control system according to claim 1, wherein a guide member is mounted between the driving gear and the actuator and has an outer wall which contacts the inner 20 wall of the actuator, thereby positioning the actuator by a contact of the inner and outer walls of the actuator.

3. A variable flow control system according to claim 2, wherein the support member is formed to project from the guide 25 member toward the driving gear.

4. A variable flow control system according to claim 2 or -17

3, wherein the guide member has a fitting section capable of fitting with an intake manifold which forms as the fluid passage an intake air passage of an internal combustion engine, and the outer wall of the fitting section contacts the inner

5 wall of the intake manifold, thereby positioning the guide member. 5. A variable flow control system according to claim 1 or 2, wherein the support member is formed to project from the 10 actuator toward the driving gear.

6. A variable flow control system substantially as described herein with reference to figures 1 to 3, figure 4 or figure 5 of the drawings hereof.

6. A variable flow control system according to any one of claims 1 to 5, wherein a sliding member, located between the support member and the driving gear, is locked on one of the 15 support member and the driving gear and is rotatably slidable on the other.

7. A variable flow control system substantially as described herein with reference to figures 1 to 3, figure 4 or figure 5 of the drawings hereof.

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À À À À À. À

À. À À À À.. À À Àe.

Amendments to the claims have been filed as follows CLAIMS

1. A variable flow control system, comprising: a valve member which rotates on a center of a driving 5 shaft member, changing a sectional area of a fluid passage; an actuator which actuates the valve member to adjust a flow of the fluid flowing in the fluid passage; a driving gear mounted on an end portion on an actuator side of the driving shaft member, and having a bore section coaxially with the driving shaft member in the end portion on the actuator side, to thereby transmit a driving force from the actuator to the driving shaft member; a support member which rotatably supports the end portion of the driving shaft member through the driving gear, sliding 15 on an inner wall of the bore section of the driving gear; and a guide member mounted between the driving gear and the actuator and having an outer wall which contacts the inner wall of the actuator, thereby positioning the actuator by a contact of the inner and outer walls of the actuator.

20 2. A variable flow control system according to claim 1, wherein the support member is formed to project from the guide member toward the driving gear.

3. A variable flow control system according to claim 1 or

e. e Be e r I e # cat Àe À 2, wherein the guide member has a fitting section capable of fitting with an intake manifold which forms as the fluid passage an intake air passage of en internal combustion engine, and the outer wall of the fitting section contacts the inner 5 wall of the intake manifold, thereby positioning the guide member. 4. A variable flow control system according to claim 1, wherein the support member is formed to project from the actuator toward the driving gear.

5. A variable flow control system according to any one of claims 1 to 4, wherein a sliding member, located between the support member and the driving gear, is locked on one of the 15 support member and the driving gear and is rotatably slidable on the other.