Throttle body fastening structure

Abstract

 A throttle body fastening structure has an induction passage constituent member (11), a throttle body (12) connected to the induction passage constituent member (11), a flange (13) formed at an end portion of the induction passage constituent member (11), to which an end surface of the throttle body (12) is joined and a bolt passing through the throttle body (12) and screwing into the flange (13) so as to fasten the throttle body (12) to the induction passage constituent member (11). The throttle body fasting structure is characterized in that a bolt hole (14a) is provided in the flange (13) through which the bolt (16) pass, a recess portion (13d) is provided in a side surface (13c) of the flange (13) and a nut (15) into which the bolt (16) is screwed is disposed in the recess portion (13d).

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a throttle body fastening structure in which a throttle body is joined and fastened with bolts to a resin induction passage constituent member.

2. Description of the Background Art

[0002] In Japanese Patent Unexamined Publication No. JP-A-11-223163, there is known a throttle body fastening structure in which in order to fasten a flange of a resin throttle body and a flange of a resin intake manifold together with bolts, metallic collars are embedded in the flanges of both the members, and the bolts which are passed through the metallic collars in the flange of the throttle body are screwed into internal threads formed on inner circumferential surfaces of the metallic collars in the flange of the intake manifold.

[0003] Incidentally, since the metallic collar of the JP-A-11-223163 on which the internal thread is formed is made up of a so-called heat insert nut which is heated and is then inserted into a hole formed in the resin flange to thereby fixed in place therein, there are possibilities that the metallic collar happens to be inclined when inserted into the hole, whereby the bolt cannot smoothly be screwed into the metallic collar and that the metallic collar is dislodged together with the bolt from the flange due to the joining force which joins the collar to the resin flange being unstable.

SUMMARY OF THE INVENTION

[0004] The invention was made in view of the situations and an object thereof is to facilitate and ensure the fastening of a throttle body to an induction passage constituent member using bolts and nuts.

[0005] With a view to attaining the object, according to a first aspect of the invention, there is proposed a throttle body fastening structure comprising:

an induction passage constituent member (11) made of resin which makes up an induction passage of an engine;

a throttle body (12) connected to the induction passage constituent member (11);

a flange (13) formed at an end portion of the induction passage constituent member (11), to which an end surface of the throttle body (12) is joined; and

at least one of bolts passing through the throttle body (12) and screwing into the flange (13) so as to fasten the throttle body (12) to the induction passage constituent member (11),

characterized in that:

at least one of bolt holes (14a) are provided in the flange (13) through which the bolts (16) pass,

at least one of recess portions (13d) are provided in a side surface (13c) of the flange (13) which lie sideways relative to a throttle body joining surface (13b) in such a manner as to extend in a direction substantially normal to a direction in which the bolt (16) passes to thereby communicate with the bolt hole (14a), and

at least one of nuts (15) into which the bolt (16) is screwed are disposed in the recess portion (13d).

[0006] According to a second aspect of the invention, as set forth in the first aspect of the present invention, it is preferable that at least two of the nuts (15) are connected together by a connecting member (19).

[0007] According to a third aspect of the invention, as set forth in the second aspect of the present invention, it is more preferable that a positioning portion (13h) is provided on the flange (13) which is adapted to be brought into engagement with the connecting member (19) so as to position the nuts (15) properly.

[0008] According to a fourth aspect of the invention, as set forth in the second aspect of the present invention, it is further preferable that an accommodating portion (20) is provided in the flange (13) which is adapted to accommodate therein the connecting member (19).

[0009] According to a fifth aspect of the invention, as set forth in the fourth aspect of the present invention, it is furthermore preferable that the connecting member (19) and the nuts (15) have a load bearing surface (P) which is level therewith, whereby the load bearing surface (P) is caused to adhere to a wall surface of the recess portion (13d) in the flange (13) by virtue of a fastening force exerted by the bolt (16).

[0010] According to a sixth aspect of the invention, as set forth in the first aspect of the present invention, it is furthermore preferable that a guide surface (13f) is provided on a wall surface of the recess portion (13d) which is far from the throttle body (12) in such a manner as to project therefrom in an inclined fashion so that an entrance side of the guide surface (13f) which faces an entrance of the recess portions (13) is lowered.

[0011] According to a seventh aspect of the invention, as set forth in the sixth aspect of the present invention, it is furthermore preferable that a bolt relief groove (13g) is formed in the guide surface (13f) so as to accommodate a distal end of the bolt (16) therein.

[0012] Note that an intake manifold (11) in embodiments corresponds to the induction passage constituent member of the invention and a projection 13h in one of the embodiments corresponds to the positioning portion of the invention.

[0013] According to the first aspect of the invention, the bolt hole through which the bolt is passed is provided in the flange of the induction passage constituent member and the recess portion is provided in the side of the flange which lies sideways relative to the throttle body joining surface, so that the nut into which the bolt is screwed is disposed in the recess portion. Thus, the throttle body can be fastened to the induction passage constituent member by screwing the bolt, which is passed through the throttle body, into the nut through the bolt hole.

[0014] In addition, the recess portion where the nut is disposed is formed in such a manner as to extend in the direction which is substantially normal to the direction in which the bolt is passed through. Thus, the nut is not dislodged from the bolt hole even when the fastening force of the bolt is exerted on the nut, and moreover, the necessity of holding the nut with the hand when the bolt is screwed thereinto is obviated by allowing the nut to be held in the recess portion, the ease with which the throttle body is fastened to the induction passage constituent member being thereby increased.

[0015] According to the second aspect of the invention, since the plurality of nuts are connected together by the connecting member, a plurality of nuts can be mounted in the recess portions in the flange simultaneously, whereby not only the ease with which the fastening work is completed can be increased but also the positioning of the nuts relative to the recess portions can be facilitated while the positional relationship of each of the plurality of nuts is kept constant.

[0016] According to the third aspect of the invention, since the nuts are positioned by bringing the positioning portion provided on the flange into engagement with the connecting member, the displacement of the nuts can be prevented, whereby the work of screwing the bolts into the nuts can be facilitated.

[0017] According to the fourth aspect of the invention, since the connecting member which connects the plurality of nuts together is accommodated in the accommodating portion provided in the flange, the connecting member is prevented from projecting from the flange, whereby a fastening portion can be made compact in size.

[0018] According to the fifth aspect of the invention, since the load bearing surface provided on the connecting member and the nuts in such a manner as to be level therewith is caused to adhere to the recess portion in the flange by virtue of the fastening force applied by the bolts, the fastening load exerted by the bolts can be dispersed to thereby prevent a local deformation of the flange, whereby the sealing performance at the connecting portion between the induction passage constituent member and the throttle body can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 

Fig. 1 is an exploded perspective view which shows a fastening portion of a throttle body;

Fig. 2 is a perspective view which shows the fastening portion of the throttle body;

Fig. 3 is an enlarged sectional view taken along the line 3-3 in Fig. 2;

Fig. 4 is a sectional view taken along the line 4-4 in Fig. 3;

Fig. 5 is a sectional view taken along the line 5-5 in Fig. 4;

Fig. 6 is an exploded perspective view which shows a fastening portion of a throttle body;

Fig. 7 is a perspective view which shows the fastening portion of the throttle body;

Fig. 8 is an enlarged sectional view taken along the line 8-8 in Fig. 7;

Fig. 9 is a sectional view taken along the line 9-9 in Fig. 8;

Fig. 10 is an exploded perspective view which shows a fastening portion of a throttle body;

Fig. 11 is a perspective view which shows the fastening portion of the throttle body;

Fig. 12 is an enlarged sectional view taken along the line 12-12 in Fig. 11;

Fig. 13 is a sectional view taken along the line 13-13 in Fig. 12; and

Fig. 14 is a sectional view taken along the line 14-14 in Fig. 13.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, modes for carrying out the invention will be described based on embodiments of the invention which are illustrated in the accompanying drawings.

[0021] Figs. 1 to 5 shown a first embodiment of the invention, wherein Fig. 1 is an exploded perspective view which shows a fastening portion of a throttle body, Fig. 2 is a perspective view which shows the fastening portion of the throttle body, Fig. 3 is an enlarged sectional view taken along the line 3-3 in Fig. 2, Fig. 4 is a sectional view taken along the line 4-4 in Fig. 3, and Fig. 5 is a sectional view taken along the line 5-5 in Fig. 4.

[0022] As shown in Figs. 1 and 2, a quadrangular flange 13 to which a metallic throttle body 12 is fastened is integrally formed at one end portion of a resin intake manifold 11 that is connected to a cylinder head. Four bolt holes 12b ... (... means plurality) are formed in the throttle body 12 in such a manner as to surround an induction passage 12a of a circular cross section. The flange 13 has a flat throttle body joining surface 13b in which a circular induction passage 13a is opened, and when the throttle body 12 is fastened to the flange 13, the induction passage 13a in the flange 13 is made to communicate with the induction passage 12a in the throttle body 12. Four collars 14 ... are embedded in the flange 13 in such a manner as to correspond, respectively, to the four bolt holes 12b ... in the throttle body 12, and nuts 15 ... are fitted, respectively, in a total of four recess portions 13d ... opened in a pair of side surfaces 13c, 13c of the flange 13. Then, four bolts 16 ... which are inserted into the bolt holes 12b ... in the throttle body 12 and bolt holes 14a ... in the collars 14 ... which are embedded in the flange 13 are screwed, respectively, into the nuts 15 ..., whereby the throttle body 12 is fastened to the flange 13 of the intake manifold 11.

[0023] As is obvious when referring to Figs. 3 to 5 together with Figs. 1 and 2, an annular groove 12d which surrounds the induction passage 12a is formed on a flange joining surface 12c of the throttle body 12, and a seal member 17, which is adapted to be brought into abutment with the flange 13, is mounted therein. In addition, an annular groove 13e which surrounds the induction passage 13a is formed on the throttle body joining surface of the flange, and seal member 18, which is adapted to be brought into abutment with the throttle body 12, is mounted therein. One of end faces of each of the collars 14 ... is exposed from the throttle body joining surface 13b while being level therewith, whereas the other of the end faces is exposed from a wall surface of each of the recess portions 13d ... while being level therewith.

[0024] The recess portions 13d ... which are opened in the side surfaces 13c, 13c of the flange 13 each have a closed end and communicate, respectively, with the bolt holes 14a ... of the collars 14 ... before the closed ends are reached. Guide surfaces 13f ... are provided, respectively, on wall surfaces of the recess portions 13d ... which are far from the throttle body 12 in such a manner as to project therefrom in an inclined fashion so that entrance sides of the guide surfaces 13f ... which face entrances of the recess portions 13d ... are lowered. Consequently, a height a of an interior of the recess portions 13d (as shown in Fig.3) ... on the entrance sides thereof is made higher than a height b on far sides thereof, and the height b of the far sides of the interior of the recess portions 13d ... is made to coincide with the height of the nuts 15 .... On central portions of the guide surfaces 13f ..., bolt relief grooves 13g ... which can avoid the contact with distal ends of the bolts 16 . . ., are formed. That is, the bolt relief groove 13g is formed in the guide surface 13f so as to house a distal end of the bolt 16 therein. In addition, the diameter of seat portions of the nuts 15 ... is set larger than the diameter of the collars 14 ... with which the seat portions of the nuts 15 ... are brought into abutment. Note that the bolt relief grooves 13g are formed in a direction defined from the side surface 13c of the flange 13 to an interior of the flange 13, and the bolt relief groove opens at the side surface 13c of the flange 13.

[0025] A working procedure for fastening the throttle body 12 to the flange 13 of the intake manifold 11 with the bolts 16 ... is as follows. Firstly, the nuts 15 ... are mounted in the recess portions 13d ... of the flange 13. As this occurs, as shown in Fig. 3, since the height a of the recess portions 13d ... on the entrance sides thereof is taller than the height b of the nuts 15 ..., the nuts 15 ... can be pushed deep into the recess portions 13d .... Following this, when the nuts 15 ... are pushed deep into the recess portions 13d ..., the nuts 15 . . . which are guided by the guide surfaces 13f ... formed in the recess portions 13d ... are caused to move towards the throttle body 12 side. Since the height b of the recesse portions 13d ... on the far sides thereof coincides substantially with the height of the nuts 15 ..., the nuts 15 ... are held in such a state as to be held between the collars 14 ... and the guide surfaces 13f ..., whereby the nuts 15 ... fall in no case even with the hand removed therefrom.

[0026] Following this, the flange joining surface 12c of the throttle body 12 is brought into abutment with the throttle body joining surface 13b of the flange 13, and the bolts 16 ... which are passed through the bolt holes 12b ... in the throttle body 12 are further passed through the bolt holes 14a ... in the collars 14 ... on the flange 13, so as thereafter to be screwed into the nuts 15 ... held in the recess portions 13d .... As this occurs, the distal ends of the bolts 16 ... which project from the nuts 15 ... fit in the bolt relief grooves 13g ... formed in the guide surfaces 13f ... with gaps provided, whereby the interference of the bolts 16 ... with the guide surfaces 13f ... can be avoided.

[0027] Thus, since the fastening force exerted by the bolts 16 ... when the throttle body 12 is fastened to the flange 13 of the intake manifold 11 with the four bolts 16 ... is borne by the wall surfaces of the recess portions 13d ... of the flange 13, even in the event that a load which attempts to separate the throttle body 12 from the flange 13 is applied, the nuts 15 ... are prevented from being dislodged from the flange 13 together with the bolts 16 ..., whereby the rigid fastening of the throttle body 12 is enabled. In addition, since the collars 14 ... are interposed between the nuts 15 ... and the flange joining surface 12c of the throttle body 12, the creep buckling of the synthetic resin flange 13 due to the fastening load exerted by the bolts 16 ... can be prevented, whereby the reduction in thickness of the flange 13 can be prevented, thereby making it possible to prevent the occurrence of a loose fastening between the throttle body 12 and the flange 13.

[0028] Figs. 6 to 9 show a second embodiment of the invention, in which Fig. 6 is an exploded perspective view which shows a fastening portion of a throttle body, Fig. 7 is a perspective view which shows the fastening portion of the throttle body, Fig. 8 is an enlarged sectional view taken along the line 8-8 in Fig. 7, and Fig. 9 is a sectional view taken along the line 9-9 in Fig. 8.

[0029] While the four nuts 15 ..., which are independent from each other, are used for the four bolts 16 ... in the first embodiment, in the second embodiment, two nuts 15, 15 which are disposed adjacent to each other are connected integrally by a plate-shaped connecting member 19. In association with this configuration, recess portions 13d, 13d which are opened in side surfaces 13c, 13c of a flange 13 are connected by a groove-shaped accommodating portion 20. Surfaces of the nuts 15, 15 and a surface of the connecting member 19 which lies to face a throttle body 12 are made into a load bearing surface P which is level and flat, and the load bearing surface P so formed can be brought into abutment with level and flat wall surfaces of the recess portions 13d, 13d and the accommodating portion 20. The other configurations of the second embodiment are identical with those of the first embodiment.

[0030] According to the second embodiment, since the fasting load exerted by the bolts 16, 16 is allowed to act evenly on the flat wall surfaces of the recess portions 13d, 13d and the accommodating portion 20 via the load bearing surface P of the nuts 15, 15 and the connecting member 19, the fastening load by the bolts 16, 16 can further be dispersed compared with the case where only the two independent nuts 15, 15 are used, whereby the contact surface pressure between a flange joining surface 12c of the throttle body 12 and a throttle body joining surface 13b of the flange 13 can be made even, thereby making it possible to enhance the sealing properties at an interface between the joining surfaces.

[0031] In addition, since the two nuts 15, 15 which are connected together by the connecting member 19 can be inserted into the two recess portions 13d, 13d simultaneously, the ease with which the throttle body 12 is assembled to the flange 13 can be increased, and in addition, since the positional relationship of the two nuts 15, 15 is determined by the connecting member 19, the accuracy with which the nuts 15, 15 are positioned relative to the recess portions 13d, 13d can be increased. Moreover, since the connecting member 19 is accommodated in the accommodating portion 20 so as not to project from the side surface 13c of the flange 13, the fastening portion where the throttle body 12 is fastened to an intake manifold 11 can be made compact in size.

[0032] Figs. 10 to 14 show a third embodiment of the invention, in which Fig. 10 is an exploded perspective view which shows a fastening portion of a throttle body, Fig. 11 is a perspective view which shows the fastening portion of the throttle body, Fig. 12 is an enlarged sectional view taken along the line 12-12 in Fig. 11, Fig. 13 is a sectional view taken along the line 13-13 in Fig. 12, and Fig. 14 is a sectional view taken along the line 14-14 in Fig. 13.

[0033] The third embodiment differs from the second embodiment in that the construction of a connecting member 19 which connects together integrally two nuts 15, 15 differs from that of the second embodiment. Namely, the connecting member 19 of the third embodiment is such as to be produced by pressing a sheet metal, and nuts 15, 15 are welded, respectively, to nut support portions 19a, 19a lying at ends of the connecting member 19, and the pair of nut support portions 19a, 19a are integrally connected together by a connecting portion 19b. A U-shaped depression 19c is formed at the center of the connecting portion 19b, and a projection 13h with which the depression 19c is brought into engagement is provided on a side surface 13c of a flange 13 in such a manner as to project therefrom. Two recess portions 13d, 13d which are adapted to accommodate therein the two nuts 15, 15 are made independent from each other.

[0034] According to the third embodiment, since the two nuts 15, 15 which are connected by the connecting member 19 can be inserted into the two recess portions 13d, 13d simultaneously, the ease with which the throttle body 12 is assembled to the flange 13 can be increased, and in addition, since the positional relationship of the two nuts 15, 15 is determined by the connecting member 19, the accuracy with which the nuts 15, 15 are positioned relative to the recess portions 13d, 13d can be increased. Moreover, since the connecting member 19 is positioned by the depression 19c formed on the connecting member 19 and the projection 13h formed on the side surface 13c of the flange 13, the accuracy with which the nuts 15, 15 fixed to the connecting member 19 are positioned can further be increased.

[0035] Thus, while the embodiments of the invention have been described heretofore, various alterations and modifications can be made thereto without departing from the spirit and scope of the invention.

[0036] For example, the induction passage constituent member of the invention is not limited only to the intake manifold 11 but may be other members such as an induction duct.

[0037] In addition, while the throttle body 12 in the embodiments is made of metal, the throttle body 12 may be made of resin.

[0038] Additionally, when used in the invention, the nut 15 is such as to include members of arbitrary shapes on which internal threads are formed.

[0039] While there has been described in connection with the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modification may be made therein without departing from the present invention, and it is aimed, therefore, to cover in the appended claim all such changes and modifications as fall within the true spirit and scope of the present invention.

[0040] A throttle body fastening structure has an induction passage constituent member (11), a throttle body (12) connected to the induction passage constituent member (11), a flange (13) formed at an end portion of the induction passage constituent member (11), to which an end surface of the throttle body (12) is joined and a bolt passing through the throttle body (12) and screwing into the flange (13) so as to fasten the throttle body (12) to the induction passage constituent member (11). The throttle body fasting structure is characterized in that a bolt hole (14a) is provided in the flange (13) through which the bolt (16) pass, a recess portion (13d) is provided in a side surface (13c) of the flange (13) and a nut (15) into which the bolt (16) is screwed is disposed in the recess portion (13d).

Claims

1. A throttle body fastening structure comprising:

an induction passage constituent member (11) made of resin which makes up an induction passage of an engine;

a throttle body (12) connected to the induction passage constituent member (11);

a flange (13) formed at an end portion of the induction passage constituent member (11), to which an end surface of the throttle body (12) is joined; and

at least one of bolts (16) passing through the throttle body (12) and screwing into the flange (13) so as to fasten the throttle body (12) to the induction passage constituent member (11),

characterized in that

at least one of bolt holes (14a) are provided in the flange (13) through which the bolts (16) pass,

at least one of recess portions (13d) are provided in a side surface (13c) of the flange (13) which lie sideways relative to a throttle body joining surface (13b) in such a manner as to extend in a direction substantially normal to a direction in which the bolt (16) passes to thereby communicate with the bolt hole (14a), and

at least one of nuts (15) into which the bolt (16) is screwed are disposed in the recess portion (13d).

2. The throttle body fastening structure as set forth in Claim 1, wherein at least two of the nuts (15) are connected together by a connecting member (19).

3. The throttle body fastening structure as set forth in Claim 2, wherein a positioning portion (13h) is provided on the flange (13) which is adapted to be brought into engagement with the connecting member (19) so as to position the nuts (15) properly.

4. The throttle body fastening structure as set forth in Claim 2, wherein an accommodating portion (20) is provided in the flange (13) which is adapted to accommodate therein the connecting member (19).

5. The throttle body fastening structure as set forth in Claim 4, wherein the connecting member (19) and the nuts (15) have a load bearing surface (P) which is level therewith, whereby the load bearing surface (P) is caused to adhere to a wall surface of the recess portion (13d) in the flange (13) by virtue of a fastening force exerted by the bolt (16).

6. The throttle body fastening structure as set forth in Claim 1, wherein a guide surface (13f) is provided on a wall surface of the recess portion (13d) which is far from the throttle body (12) in such a manner as to project therefrom in an inclined fashion so that an entrance side of the guide surface (13f) which faces an entrance of the recess portions (13) is lowered.

7. The throttle body fastening structure as set forth in Claim 6, wherein a bolt relief groove (13g) is formed in the guide surface (13f) so as to house a distal end of the bolt (16) therein.

Drawing