JPH07158524A - Fastening structure of surge tank and throttle body of intake system for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide a fastening structure of the surge tank and the throttle body of intake system for an internal combustion engine which can make the fastening work easy, as well as can make the fastening condition of the flange of the surge tank formed of a resin material, and the flange of the throttle body formed of an aluminum material or the like in a solid form. CONSTITUTION:This fastening structure consists of a bolt to penetrate a through hole provided to the abutting position of the flanges of a surge tank and a throttle body, and a nut 11 screwed to the bolt, and the flange 10a of the surge tank has a U-shaped cut fitting groove 10c opened to the outer side at the flange face direction of the flange at its one side, and a projection 10b to abut its tubular screw 11a to the outer periphery in the condition to insert and fit the tubular screw 11a so as to press it against the bottom of the cut fitting groove 10c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastening structure for separate parts, and more particularly to a fastening structure for a surge tank of an intake system for an internal combustion engine mounted on an automobile or the like and a throttle body.

[0002]

2. Description of the Related Art Conventionally, as such a fastening structure, a structure as shown in FIGS. 1 to 3 is known.
Here, FIG. 1 is a plan view of an intake device for an engine. This intake device has three regions, namely, a branch portion (I) forming only an intake passage, and a multiple butterfly for opening and closing the intake passage. An aluminum material is used separately for the valve body part (II) that internally houses the valve and forms the intake passage, and the cover part (III) that forms the surge tank and partially houses the port shell that forms part of the bypass intake passage. Then, the respective mounting flange surfaces are butted and joined together by fastening means (not shown) such as bolts.

Further, a flange portion 1a having an opening is formed on a part of the outer wall of the valve body portion (II) and the cover portion (III) forming the surge tank, and the engine output is output with respect to the flange portion 1a. A throttle body 2 in which a throttle valve for adjusting the throttle valve is installed is fastened and fixed by a bolt 3 by abutting a flange portion 2a thereof. The throttle body 2 is also made of an aluminum material and has a rotary shaft 2c for supporting a throttle valve (not shown) arranged in the intake passage.
A rotary drum 2d for locking a wire or the like is fixed to one end of the rotary drum 2 and the throttle valve can be opened and closed by rotating the rotary drum 2d.

Here, the flange portion 1a of the intake device body 1
The fastening structure of the throttle body 2 with respect to the above will be described in detail. As clearly shown in FIG. 2, which shows a cross section taken along the line AA in FIG. 1, screw holes 1s are formed in the flange portion 1a of the intake device body (four corners). On the other hand, a through hole 2h is formed in the flange portion 2a of the throttle body (similarly, a total of four). Then, with the end surfaces of both flange portions being in abutting engagement with each other via the seal member 4, a bolt 3 having a flat washer or a spring washer 5 incorporated therein.
However, it has a structure in which the through hole 2h is inserted and screwed into the screw hole 1s, so that the both are firmly fastened.

Another fastening structure is shown in FIG. In this, the flange portion 1a of the intake device body is also formed with a through hole 1h instead of a screw hole,
The bolt 3 and the nut 7 are used to fasten the flat washer 5 and the spring washer 6 in between. On the other hand, as one of the policies of today's automobile development, development of a fuel-efficient vehicle by reducing the weight of the vehicle, or development of a low-cost vehicle by changing the material and simplifying the manufacturing process is being considered.

Therefore, as for the above-mentioned air intake device which has been conventionally formed of a metal material such as an aluminum material, the use of resin as a product is being studied. However, all the parts that make up the conventional air intake system are made of resin,
Simply by adopting the conventional fastening structure and fixing the throttle body, the mechanical strength of the resin flange part is small, and the loosening of the fastening part due to the sag of the flange part due to thermal creep or the like, or New problems such as difficulty in forming screw holes and the like and difficulty in post-processing occur, and it is difficult to secure the same fastening strength and reliability as in the past.

[0007]

In view of the above problems of the prior art, the object of the present invention is to provide a fastening flange portion formed of a resin material having a low mechanical strength. An object of the present invention is to provide a fastening structure for a surge tank and a throttle body of an intake system for an internal combustion engine, which is capable of maintaining the initial fastening strength to strengthen the fastening state and facilitating the fastening work.

[0008]

According to the fastening structure of the present invention, the flange portion of the throttle body for adjusting the output of the engine is brought into contact with the surge tank flange portion forming a part of the intake system for the internal combustion engine to be fastened. A fastening structure for a surge tank of an intake system for an internal combustion engine and a throttle body for fastening both flange portions by means, wherein the flange portion of the surge tank is made of a resin material, and the fastening means is The surge tank includes a bolt penetrating a through hole provided in a contact portion between the flange portion of the surge tank and the flange portion of the throttle body, and a nut screwed with the bolt, and the nut has an internal thread groove on an inner wall. A flanged nut comprising a tubular screw portion and a rectangular flange portion having a radial expansion at the axial end portion of the tubular screw portion, The flange portion of the serial surge tank,
One has a U-shaped cutout fitting groove that opens toward the outside of the flange portion in the direction of the flange surface, and the tubular screw portion was fitted and fitted into the cutout fitting groove. It is characterized in that it has a projection that presses the bottom of the cutout fitting groove by abutting the outer circumference of the cylindrical threaded portion in this state.

In the fastening structure, an elastic member is disposed between the bolt or nut and the flange portion of the surge tank to urge the flange portion of the surge tank toward the flange portion of the throttle body. It is also characterized by having.

[0010]

According to the fastening structure of the present invention, the nut is a flanged nut composed of a tubular screw portion and a flange portion, and when the flanged nut is assembled to the flange portion, one of the fitting portions is a flange surface. Since a U-shaped notch fitting groove that opens outward in the direction is formed and a projection that partially narrows the groove width of this fitting groove is formed on the inner wall of the groove, When the cylindrical screw part is fitted and fitted into the fitting groove, the projection is deformed within the range of the elastic region to allow the fitting, and after the fitting, the outer periphery of the cylindrical screw part is held by elastic return. Acts to fix.

Further, since an elastic member for urging the flange portion toward the mating flange portion is arranged on the side of the flange portion formed of the resin material and the structure is to be fastened with the bolt and the nut, the resin material is used. Even if the flange portion made of is plastically deformed due to thermal creep or the like, the urging force of the elastic member is always acting directly, so that the reduction of the tightening axial force is suppressed.

[0012]

Embodiments of the fastening structure according to the present invention will be described below with reference to the drawings. FIG. 4 shows the intake device main body 10.
FIG. 3 is an external plan view showing a state in which the throttle body 2 is fixed by adopting the fastening structure according to the present invention. As shown, the intake device body 10 has three regions I, II, II.
It consists of a combination of resin injection molded parts forming I.
That is, a branch portion (I) connected to the head intake port of the engine, a valve body portion (II) that houses a multiple butterfly valve that opens and closes the intake passage, a cover portion (III that forms a surge tank and a bypass intake passage). ) Are respectively molded by an injection molding method or the like, and thereafter, they are integrally bonded by vibration welding or the like on the joining flange surface.

The flange portion 10a, to which the throttle body 2 made of aluminum or the like is attached, is made of a resin material like the intake device main body 10 and is made of a valve body (II).
And the cover portion (III) are integrally formed. In addition, in FIG. 4, the same reference numerals as those in FIG. 1 indicate the same parts as those in the related art.

Here, the flange portion 10a formed of a resin material will be described in detail. FIG. 5 is a side view (throttle body 2) of the intake device body 10 taken along the arrow R in FIG.
It shows the unmounted state), and as shown in this figure,
The flange portion 10a has a substantially rectangular outer shape, and an opening portion 10b for communicating the inside of the surge tank with the outside air is formed in the center portion thereof.

Further, U-shaped notch fitting grooves 10c are provided at four corners of the flange portion 10a so as to open outward in the diagonal direction of the flange surface. Then, the cylindrical threaded portion 11a of the flanged nut 11, which is a part of fastening means described later, is fitted into the cutout fitting groove 10c in a direction parallel to the flange surface.

Here, the fitting relationship between the notch fitting groove 10c and the nut 11 will be described in more detail. Figure 6
FIG. 6A is a view for explaining such a fitting relationship, and FIG.
Is an external perspective view showing the flange portion 10a region of the intake surge tank, and FIG. 6 (b) is a nut 1 in the notch fitting groove 10c.
FIG. 2 is a partially enlarged view showing a state in which 1 is fitted. As shown in this figure, a pair of U-shaped notch fitting grooves 10c provided at the four corners of the flange portion 10a are provided with a pair of protrusions 10d facing each other on their inner wall surfaces. It is narrower than other groove widths. On the other hand, the nut 11 forming a part of the fastening means includes a cylindrical threaded portion 11a having an internal thread groove 11c formed on the inner wall thereof, and a rectangular collar portion having a radial expansion at the axial end of the cylindrical threaded portion. 11b
It is composed of and. And this nut with a collar 1
1 is fitted into the cutout fitting groove 10c, the tubular screw portion 11a of the flanged nut 11 is cutout into the fitting groove 10c.
The cylindrical threaded portion 11a reaches the bottom portion 10e of the notch fitting groove 10c by pushing it with further force when it is inserted from the opening side of c and abuts against the pair of protrusions 10d, and the notch fitting is performed. It is fixed so as to be held by the inner wall of the groove 10c and the pair of protrusions 10d. At this time,
The pair of protrusions 10d are deformed within the elastic range when the tubular screw portion 11a is pushed in to allow fitting.
After the insertion, it acts to elastically return, that is, to clamp and fix the outer periphery of the cylindrical threaded portion by a spring action, and prevents the nut from falling off until the throttle body 2 is completely tightened and fixed.

Such a method of fitting the nut 11 into the U-shaped fitting groove 10c having one end opened from the direction parallel to the flange surface is particularly advantageous in the space perpendicular to the flange surface of the flange portion 10a. This is one of the preferable attachment methods when there is no such item. This is because the circular hole can be adopted if the movement stroke for fitting the tubular screw portion in the direction perpendicular to the flange surface can be secured.

Next, a fastening method for assembling the throttle body 2 to the intake device body 10 will be described. Figure 7
4 is a sectional view taken along the line BB in FIG. 4, and as shown in the drawing, the flange portion 10 of the intake device body is
In a, a hand washer 13 and a pair of disc springs 12 are provided between the flange portion 11b of the flanged nut 11 and the end surface of the flange portion 10a.
The flanged nut 11 is fitted in the state of interposing. Then, the flange portion 2a of the throttle body 2
However, the flange portion 1 of the intake device main body is inserted through the seal member 4.
0a, the flange surfaces are brought into close contact with each other, and the bolt 3 incorporating the flat washer 5 is inserted into the through hole 2
It is screwed into the thread groove 11c of the flanged nut 11 via h.

According to such a fastening structure, the flange portion 10a made of the resin material is always urged by the disc spring 13 so as to be in close contact with the flange portion 2a of the throttle body. Therefore, even if the resin flange portion 10a undergoes permanent strain (sag) such as compression deformation due to thermal creep or the like,
The spring force of the disc spring can prevent a reduction in the attachment force for bringing the throttle body into close contact with the main body, so that the fastened state of both can be reliably maintained even against external vibration and the like. In particular, when the amount of deformation of the resin flange portion 10a is large, it is preferable to dispose the disc spring 12 on the side of the flange portion 10a as shown in FIG. 7 because the spring force directly acts on it.

On the other hand, when the amount of deformation of the resin flange portion 10a is not so large, as shown in FIG. 8, the disk spring 12 is attached to the flange portion 2a side of the throttle body by using the conventional bolt 3 and nut 7. It may be arranged. Further, in the structure using the flanged nut 11 as shown in FIG. 7, for example, by forming the rotation prevention wall 10m or the slip-out prevention wall 10n on a part of the outer wall of the intake device body 10, for example, the collar. Even when the fitted nut 11 and the notch fitting groove 10c are loosely fitted to each other, the nut 11 can be prevented from coming off. Therefore, the disc spring 1 in advance
It is also possible to assemble only the flanged nut 11 incorporating the 2 and the plain washer 13 into the flange portion 10a of the intake device body, and assemble the throttle body 2 in a separate process. It also leads to greater flexibility in process design.

[0021]

As described above, according to the fastening structure of the present invention, as the nut, the cylindrical threaded portion having the internal thread groove on the inner wall, and the axially end portion of the cylindrical threaded portion are spread in the radial direction. A flanged nut consisting of a rectangular collar part is used, and the flange part made of resin material
One side forms a U-shaped cutout fitting groove that opens outward in the flange surface direction, and the tubular screw part of the flanged nut is fitted into this fitting groove. By providing a protrusion on the inner wall of the fitting groove that presses the part against the bottom of the fitting groove, it is easy to attach the flanged nut to the flange part, and it is possible to prevent the nut from falling off. In this case, it is not necessary to hold the nut and the tightening work can be done easily.

Further, an elastic member for urging the flange portion toward the mating flange portion is arranged on the flange portion side made of a resin material, and is fastened with a bolt and a nut. Therefore, even if the resin flange portion is plastically deformed due to thermal creep, etc., the urging force of the elastic member is always acting directly, so that it is possible to suppress a decrease in the axial force, and thus, the close contact of both flange portions. It is possible to maintain the state and firmly maintain the fastening of both.

[Brief description of drawings]

FIG. 1 is a plan view showing a conventional fastening state of a surge tank of an intake system and a throttle body.

FIG. 2 is a cross-sectional view taken along the line AA in FIG.

FIG. 3 is a cross-sectional view showing another conventional fastening structure.

FIG. 4 is a plan view of an intake device and a throttle body that employ the fastening structure according to the present invention.

5 is an outer side view of the intake device according to the arrow R in FIG.

6 shows an embodiment of a fastening structure according to the present invention, FIG. 6 (a) is an external perspective view of a resin flange portion and a flanged nut, and FIG. 6 (b) is a cutout of the flanged nut. It is a figure which shows the state fitted in the notch fitting groove.

FIG. 7 shows an embodiment of the fastening structure according to the present invention, and is a cross-sectional view taken along the line BB in FIG.

FIG. 8 is a cross-sectional view showing another fastening structure using a disc spring as an elastic member.

[Explanation of symbols for main parts]

 2a Throttle body flange 3 Bolts 4 Sealing means 5 Plain washer 10a Surge tank flange 10c Notch fitting groove 10d Protrusion 10e Bottom 11 Collar nut 11a Cylindrical screw 11b Collar 11c Screw groove 12 Disc spring (elastic) Material) 13 plain washers

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Akira Takahashi 5-3-8 Shiba, Minato-ku, Tokyo Within Mitsubishi Motors Corporation (72) Inventor Toru Hashimoto 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Mitsuhiro Miyake 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Shigekazu Yamauchi 5-33, Shiba, Minato-ku, Tokyo No. Mitsubishi Motors Corporation (72) Inventor Akiyuki Shinjo 2480 Kuno, Odawara-shi, Kanagawa Mikuni Odawara Factory (72) Inventor Shigeo Tsukagoshi 2-14-14 Shin-Yokohama, Kohoku-ku, Yokohama 10 Within Tokyo Filter Co., Ltd. (72) Inventor Hisawa Miya 2-14 Shin-Yokohama, Kohoku-ku, Yokohama-shi, Kanagawa 10 Inside Tokyo Filter Co., Ltd. (72) Naoto Nishimoto New in Kohoku-ku, Yokohama-shi, Kanagawa Hama 2-chome 14 address 10 Tokyo Roki within Co., Ltd.

Claims (2)

[Claims] 1. An internal combustion engine in which a flange portion of a throttle body for adjusting engine output is brought into contact with a surge tank flange portion forming a part of an intake system for an internal combustion engine, and the flange portions are fastened by fastening means. A structure for fastening a surge tank of an intake system for a vehicle to a throttle body, wherein a flange portion of the surge tank is formed of a resin material, and the fastening means is a flange portion of the surge tank and a flange of the throttle body. A bolt that penetrates a through hole provided in a portion that abuts with the portion, and a nut that is screwed into the bolt, wherein the nut has a cylindrical threaded portion having an internal thread groove on an inner wall, and the cylindrical threaded portion. Is a flanged nut consisting of a rectangular flange part that has a radial expansion at the axial end of the surge tank, and one of the flange part of the surge tank is A U-shaped cutout fitting groove that opens outward in the flange surface direction of the flange portion is provided, and the tubular screw portion is fitted and fitted into the cutout fitting groove. A fastening structure for a surge tank of an intake system for an internal combustion engine and a throttle body, comprising a protrusion for abutting the outer circumference of the tubular screw portion to press the tubular screw portion against a bottom portion of the cutout fitting groove. 2. The elastic member is disposed between the bolt or nut and the flange portion of the surge tank and biases the flange portion of the surge tank toward the flange portion of the throttle body. The fastening structure for a surge tank of an intake system for an internal combustion engine and a throttle body according to claim 1.