JPH05125964A - Throttle body - Google Patents

Abstract

(57) [Abstract] [Purpose] In the throttle body, by reducing the force applied to the throttle valve shaft and the bearing portion, the throttle valve shaft and the bearing portion can be converted to low-strength members, and simplification can be achieved. Make it easy and fully automate the assembly line. [Structure] A throttle body having a main body 1 and a butterfly type throttle valve 4 and having a throttle valve shaft 3 held by a bearing portion 1a provided in the main body 1 is connected to a substantially coaxial line of the throttle valve shaft 3. , The throttle lever 8 for driving the throttle valve shaft 3 and the torsion springs 9a, 9 for imparting rotational torque to the throttle valve shaft 3
b and the second shaft 7 supported by the bearing portion 6
Have. In addition, the bearing portion 6 of the second shaft 7 is formed as a separate member from the main body 1, and the second shaft 7 and the bearing portion 6 are a subassembly in which the lever 8 and the torsion springs 9a and 9b are arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle body installed in an intake passage of an internal combustion engine and controlling the flow rate of air supplied to the internal combustion engine.

[0002]

2. Description of the Related Art In a conventional throttle body for an internal combustion engine, as described in Japanese Utility Model Laid-Open No. 2-18630, one end portion of a throttle valve shaft projects from a main body, and the throttle valve shaft is attached to the protruding portion. It had a structure in which a driving lever and a spring that gives a rotational torque to the throttle shaft were arranged.

[0003]

In the above-mentioned conventional throttle body, since the lever and the spring are arranged at the portion where the throttle valve shaft projects from the main body, excessive rotational torque from the spring is directly applied to the throttle valve shaft. It costs
Since the protruding portion beyond the bearing of the throttle valve was long, it was easy to receive the vibration load due to the overhang, the bending moment, and the negative pressure force of the throttle portion. Therefore, it is necessary to improve the strength of the throttle valve shaft and the bearing portion and the dimensional accuracy.

Generally, it is difficult to automate the assembly of springs, but when these are installed directly on the throttle shaft, it is necessary to arrange the assembly process of this spring part in the throttle valve main assembly line, and therefore the throttle It was difficult to fully automate the body assembly line.

A first object of the present invention is to provide a throttle body which can reduce the force applied to the throttle valve shaft and the bearing portion so as to convert the throttle valve shaft and the bearing portion into low-strength members and simplify the structure. Is to provide.

A second object of the present invention is to provide a throttle body in which the assembly line can be easily fully automated by forming a sub-assembly in a portion that is difficult to automate.

[0007]

In order to solve the above-mentioned problems, the present invention comprises a main body forming a part of an intake passage of an internal combustion engine, and a butterfly type throttle valve, and a bearing portion provided in the main body. A throttle body having a throttle valve shaft rotatably held by a first shaft as the throttle valve shaft;
A first shaft which is coaxially connected to the first shaft, is provided with a lever for driving the first shaft and a spring for applying a rotational torque to the first shaft, and is separate from the first shaft supported by a bearing portion. It has two axes.

Preferably, the bearing portion of the second shaft is formed as a separate member from the main body, and the second shaft and the bearing portion constitute a sub-assembly including the lever and the spring.

Preferably, a throttle sensor for detecting the rotation angle of the first shaft is installed on the second shaft.

Further, preferably, a seal member for maintaining airtightness with the outside of the intake passage in the main body is arranged at a portion of the first shaft projecting outside the main body, and the first shaft and the second shaft are provided. And are connected outside the sealing member.

Further, preferably, a seal member for maintaining airtightness with the outside of the intake passage in the main body is arranged at a portion of the second shaft projecting into the main body, and the first shaft and the second shaft are provided. Are connected inside the sealing member.

[0012]

In the present invention, the second shaft is connected substantially coaxially with the first shaft as the throttle valve shaft, and the lever for driving the throttle valve shaft and the spring for giving the rotary torque to the throttle valve shaft are provided. By arranging it on the second shaft, it is possible to greatly reduce the rotational torque from the spring that the first shaft and the bearing portion thereof receive. Therefore, the throttle valve shaft and the bearing portion can be formed of a low strength material such as resin.

Further, since the second shaft is separate from the first shaft, it does not receive the negative pressure force generated in the throttle valve portion, and since the second shaft is supported by the bearing portion, there is no overhang as in the conventional case. ,
The second axis is no longer subjected to vibration loads and bending moments. Therefore, the second shaft can be formed of a simple material that does not require the strength of the conventional throttle valve shaft.

Further, by forming the bearing portion of the second shaft as a member separate from the main body, and by forming the second shaft and the bearing portion into a sub-assembly including a lever and a spring, a spring that is difficult to automate in assembly can be obtained. Can be formed as a separate process,
It is easy to fully automate the assembly line for the throttle body.

Further, a seal member for maintaining airtightness with the outside of the intake passage in the main body is arranged at a portion of the first shaft protruding outside the main body, and the first shaft and the second shaft are provided outside the seal member. By connecting them, it is possible to change from a structure in which the end portion of the throttle valve shaft projects long from the main body as in the conventional product to a structure in which the second shaft is connected to the first shaft as the throttle valve shaft as in the present invention. It can be done easily.

Further, a seal member for maintaining airtightness with the outside of the intake passage in the main body is arranged at a portion of the second shaft projecting into the main body, and the first shaft and the second shaft are connected inside the seal member. By doing so, the main body can be divided into a portion having the first shaft and a portion other than that and assembled in advance, and the two portions can be combined to easily assemble the main body. Can fully automate the assembly line for the throttle body.

[0017]

Embodiments of the throttle body according to the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a sectional view of a throttle body according to an embodiment of the present invention in a plane including a throttle valve shaft. For simplification, the throttle valve shaft (first shaft) 3 and the second shaft 7 are shown in a sectional view only at their connecting portions. In FIG. 1, a main body 1 of a throttle body forms an intake passage 2, and a throttle valve shaft 3 as a first shaft having a throttle valve 4 fixed by a screw 4a is provided below the intake passage 2 by a bearing portion 1a. It is rotatably held on the main body 1. In the main body 1, the intake passage 2
In order to maintain the airtightness between the main body and the outside of the main body, a seal member 5a is arranged on the main body outside projection of the throttle valve shaft 3. Body 1
A housing 6 that is a member separate from the main body 1 and that provides a bearing portion that rotatably supports the second shaft 7 over the entire length is fixed to the main body 1 by screws or the like not shown.
The second shaft 7 and the throttle valve shaft 3 have a protrusion 7 at the tip of the second shaft 7 in a key groove 3a provided on the throttle valve shaft 3 outside the seal member 5a.
They are connected by engaging a and are arranged so that their axes are substantially the same, and the rotational force of the second shaft 7 is transmitted to the throttle valve shaft 3. Some play may be provided between the key groove 3a and the projection 7a of the connecting portion between the throttle shaft 3 and the second shaft 7, and this play may be used to connect the second shaft 7 to the throttle shaft 3. The insertion is facilitated, and the gap between the throttle valve shaft 3 and the second shaft 7 after the assembly and insertion due to a machining error is absorbed by this play, so that no stress is applied to the connecting portion. FIG. 2 shows this connecting portion as II-II of FIG.
It is sectional drawing seen from the direction. As you can see from this figure,
The key groove 3a has an oval shape. The key groove 3a
The shape of is not limited to such an oval shape, but may be another shape such as a triangle or a star.

The second shaft 7 has a throttle lever 8 which is rotationally driven by an accelerator wire (not shown),
And the torsion springs 9a and 9b are arranged. The second shaft 7 is given a rotational torque by the torsion springs 9a and 9b, and the stopper 6 provided in the housing 6 is provided.
When the throttle lever 8 hits a, it is pressed in one direction. Further, a throttle sensor 10 for detecting the rotation angle of the throttle valve shaft 3 is attached to the housing 6, and the throttle sensor 10 is mounted on the second shaft 7 by a sensor drive lever 10a. The rotation is given.

According to this embodiment, the second shaft 7 is separated from the throttle valve shaft 3 and connected so that the rotational force can be transmitted on the same axis line, so that the torsion spring 9 which the throttle valve shaft 3 receives.
The rotational torque from a and 9b can be reduced significantly. Therefore, the throttle shaft 3 can be formed of a low strength material such as resin. Further, since the second shaft 7 is a separate body from the throttle shaft 3, it is not affected by the negative pressure of the throttle shaft 3, and the bearing portion 6 supporting the entire length of the second shaft 7 is arranged, so that the conventional shaft 6 is provided. No overhang, no vibration load or bending moment. Therefore, the second shaft 7 can be formed of a simple material that does not require the strength of the conventional throttle valve shaft. In addition, the bearing 6 of the second shaft 7 is formed as a separate member from the main body 1, and the second shaft 7 and the bearing 6 are a sub-assembly including a lever and a spring, so that the assembly can be automated. The difficult spring can be formed as a separate process, and the automation of the throttle body main assembly line can be facilitated easily.

FIG. 3 is a sectional view of a throttle body according to another embodiment of the present invention, taken along a plane including a throttle valve shaft. For simplification, the throttle valve shaft (first shaft) 3 and the second shaft 7 are shown in a sectional view only at their connecting portions. In the present embodiment, as shown in the drawing, the throttle sensor 10 is attached to the main body 1 via a seal member 5b, and a sensor drive lever 10a fixed to the throttle valve shaft 3 prevents the throttle valve shaft 3 from rotating. The throttle lever 8 is arranged at the end of the second shaft 7 opposite to the throttle valve shaft 3. The other configuration is the same as that of the embodiment shown in FIG. According to this embodiment, the same effect as that of the embodiment shown in FIG. 1 can be obtained. Further, in this embodiment, the throttle sensor 1
As shown in FIG.
Similarly to the embodiment described above, even if there is some play as described above in the connection between the throttle valve shaft 3 and the second shaft 7, the throttle valve shaft 3 can be pressed in one direction, and the second shaft The throttle shaft 3 can be rotated uniformly according to the rotational force of 7.

FIG. 4 is a sectional view of a throttle body in a plane including a throttle shaft according to another embodiment of the present invention.
For simplicity, only the connecting portion of the second shaft 7 and the second shaft 7 is shown in a sectional view. Further, the throttle valve 4 is shown in a state in which it is further rotated as compared with the embodiment shown in FIGS. In this embodiment, the method for connecting the throttle shaft 3 and the second shaft 7 is as shown in FIG.
However, as shown in the figure, this connecting portion is located inside the main body of the seal member 5a, and the seal member 5a is arranged at the portion where the second shaft 7 projects into the main body 1. Further, in the present embodiment, the throttle valve 4 is formed integrally with the throttle valve shaft 3, and the sub spring 11 is built in the end portion of the throttle valve shaft 3 opposite to the second shaft 7. With this sub-spring 11, the throttle valve shaft 3 can be pressed in one direction even if there is some play in the connection between the throttle shaft 3 and the second shaft 7 as described above. The throttle valve shaft 3 can be rotated uniformly in accordance with the rotational force of.

Further, the main body portion of the throttle body according to the present embodiment has a divided body 1b which is divided from the main body 1 below the plane including the substantial axis of the throttle valve shaft 3, as shown in FIG. FIG. 5 is a partial perspective view of the main body portion shown in FIG. 4 viewed from the V direction, in which the main body 1 is indicated by a dashed line and the other portions are indicated by solid lines. A snap 1c having an opening is provided at the upper end of the divided body 1b.
The opening D has a width D slightly smaller than the outer diameter d of the throttle valve shaft 3 and has a shape capable of holding the throttle valve shaft 3. The throttle valve shaft 3 has an elastic deformation range within the snap 1c. It is engaged and held rotatably. Also, the main body 1 and the divided body 1
In order to ensure airtightness with the b, a groove 1d as shown in the figure is provided on the surface of the divided body 1b, and the O-ring 12 is fitted therein. With the above configuration, the throttle valve shaft 3 and the throttle valve 4 are assembled in advance in the divided body 1b to form a sub-assembly, and the sub-assembly is inserted from below the main body 1 in FIG. The body of the throttle body can be easily assembled. In particular, this embodiment is advantageous when the throttle valve 4 and the throttle valve shaft 3 are integrally formed of resin or the like. still,
Since the seal member 5a is arranged on the second shaft 7, it is not necessary to incorporate the seal member 5a in the sub-assembly, and after the sub-assembly is incorporated in the main body 1, the second shaft 7 is inserted through the seal member 5a. You can connect to.

Further, in the present embodiment, even when the split body 1b is not provided with the snap 1c, the throttle valve shaft 3 and the like can be sequentially inserted into the main body 1 from below the main body 1 to assemble. .. Furthermore, in the present embodiment, the O-ring 12 is used to ensure the airtightness between the main body 1 and the divided body 1b.
However, when the divided body 1b is made of metal, it can be pressed into the main body 1, and when the divided body 1b is made of resin, it can be fixed by heat welding or the like. Does not need to use the O-ring 12.

According to the present embodiment, not only the same effect as that of the embodiment shown in FIG. 1 or 3 can be obtained, but also the divided body 1b is assembled beforehand with the throttle shaft 3 and the throttle valve 4 as a sub-assembly. Since it can be formed in a separate process and the body portion of the throttle body can be easily assembled, this also facilitates full automation of the throttle body body assembly line.

[0026]

According to the present invention, the first shaft and the second shaft as the throttle shaft are connected on a substantially coaxial line, and the lever and the spring are arranged on the second shaft. The rotational torque from the spring that the bearing and its bearing portion receive can be greatly reduced. Therefore, the throttle valve shaft and its bearing portion can be made of a low strength material such as resin.

Further, since the second shaft is a separate body from the first shaft, it does not receive the negative pressure force generated in the throttle valve portion, and the second shaft is supported by the bearing portion, so that the second shaft is free from vibration load and It becomes difficult to receive a bending moment, and can be formed of a simple material.

Further, by forming the bearing portion of the second shaft as a separate member from the main body, and by forming the second shaft and the bearing portion into a sub-assembly including a lever and a spring, a spring that is difficult to automate in assembly can be obtained. Can be formed as a separate process,
It is easy to fully automate the assembly line for the throttle body.

Further, by arranging the seal member at the portion of the first shaft projecting outside the main body and connecting the first shaft and the second shaft outside the seal member, the conversion from the conventional product to the present invention can be achieved. It can be done easily.

Further, by disposing the seal member in a portion of the second shaft projecting into the main body, and connecting the first shaft and the second shaft inside the seal member, the portion provided with the first shaft and the other parts. It is possible to easily assemble the main body by assembling these parts separately and then to assemble them, which also makes it possible to fully automate the throttle body main assembly line.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along a plane including a throttle valve shaft of a throttle body according to an embodiment of the present invention.

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

FIG. 3 is a cross-sectional view of a throttle body according to another embodiment of the present invention in a plane including a throttle shaft.

FIG. 4 is a cross-sectional view of a throttle body in a plane including a throttle shaft according to still another embodiment of the present invention.

FIG. 5 is a partial perspective view of the main body portion shown in FIG. 4 viewed from the V direction.

[Explanation of symbols]

 1 Main body 2 Intake passage 3 Throttle valve shaft (first shaft) 3a Key groove 4 Throttle valve 5a, 5b Seal member 6 Housing (bearing part of second shaft 7) 7 Second shaft 7a Projection part 8 Throttle lever 9a, 9b Torsion Spring 10 Throttle sensor

Claims (5)

[Claims] 1. A throttle body having a main body forming a part of an intake passage of an internal combustion engine, a butterfly type throttle valve, and a throttle valve shaft rotatably held by a bearing portion provided in the main body. In, the first shaft as the throttle valve shaft,
A first shaft which is coaxially connected to the first shaft, is provided with a lever for driving the first shaft and a spring for applying a rotational torque to the first shaft, and is separate from the first shaft supported by a bearing portion. A throttle body having two axes. 2. The bearing portion of the second shaft is formed as a separate member from the main body, and the second shaft and the bearing portion constitute a sub-assembly including the lever and the spring. The throttle body according to item 1. 3. The throttle body according to claim 1, wherein a throttle sensor for detecting a rotation angle of the first shaft is installed on the second shaft. 4. A seal member for maintaining airtightness with respect to the outside of an intake passage in the main body is arranged at a portion of the first shaft projecting outside the main body, and the first shaft and the second shaft are the same. The throttle body according to any one of claims 1 to 3, wherein the throttle body is connected to the outside of the seal member. 5. A seal member for maintaining airtightness to the outside of an intake passage in the main body is arranged at a portion of the second shaft protruding into the main body, and the first shaft and the second shaft are the seals. The connection is provided inside the members.
Throttle body according to any one of 1 to 3.