JPH056134U - Intake device for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an intake device for an internal combustion engine capable of maintaining a sealing property while avoiding interference between a valve shaft and a partition wall at a through hole. [Structure] The valve shaft 16 is provided with peripheral grooves 1 and 5 only on the downstream side 16a in the flow direction, which is the negative pressure side, so that the outer peripheral side surface of the partition wall 13 is aligned with the partition surface 13b of the partition wall 13. Then, when molybdenum 25 as a sealing material is applied, it is avoided that molybdenum 25 is stored in the peripheral grooves 1 and 5 and flows into the through hole 13a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an intake device for an internal combustion engine, and more particularly to a dual throttle chamber intake device having throttle valves provided in two intake passages and having coaxial valve shafts.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, there is an intake system for an internal combustion engine as shown in FIG. That is, two intake passages 11 and 12 are provided in parallel, a through hole 13a is formed in the partition wall 13 of these intake passages 11 and 12, and each intake passage 11 passes through this through hole 13a. , 12 valve shafts 16 of throttle valves 14, 15 are provided coaxially, and both ends of the valve shafts 16 are rotatably held by intake passage wall portions 11a, 12a via bearings 17, and intake passages 11, 12 are It is designed to open and close.

Reference numeral 18 is a lip seal, and 19 is a retainer thereof.

[0004]

[Problems to be solved by the device]

 By the way, when such an intake device is operated under negative pressure, at the beginning of opening of the throttle valves 14 and 15, the valve shaft 16 bends to the negative pressure side between the bearings 17 at both ends (arrow C), and the partition wall 13 of the through hole 13a is opened. It interferes with (D part). Therefore, the inner diameter of the through hole 13a is increased to such an extent that the valve shaft 16 and the partition wall 13 do not interfere with each other to secure a clearance (E) between the valve shaft 16 and the partition wall 13 in the through hole 13a, while at the same time providing a sealing property. In order to ensure this, molybdenum 20 is applied as a sealing material around both sides of the through hole 13a of the valve shaft 16.

However, as shown in FIG. 5, when molybdenum 20 is applied, the molybdenum 20 flows on the surface of the valve shaft 16 and covers the surface of the valve shaft in the through hole 13a before the molybdenum 20 dries (see X in the figure). However, there is a problem that this clearance is eventually damaged and the valve shaft 16 bends toward the negative pressure side at the start of operation under negative pressure, and the valve shaft 16 interferes with the negative pressure side.

In view of the above problems, the present invention provides an intake device for an internal combustion engine that can maintain the sealability while avoiding the interference between the valve shaft and the partition at the through hole. The purpose is to

[0007]

[Means for Solving the Problems]

 Therefore, according to the present invention, the valve shafts of the throttle valves for the respective intake passages are coaxially provided through the through holes formed in the partition wall between the two intake passages arranged in parallel, and both ends of the valve shafts are coaxially provided. In an intake device for an internal combustion engine, which is rotatably held in a wall portion of an intake passage via a bearing, a peripheral groove is formed around a valve shaft directly inside the partition wall and facing at least a negative pressure side. A seal material is applied around the valve shaft outside the circumferential groove along each circumferential groove.

[0008]

[Action]

 With the above configuration, even if the seal material applied along the circumferential groove around the valve shaft outside the circumferential groove flows on the valve shaft surface until it dries, at least the valve shaft facing the negative pressure side The sealing material is stored in the peripheral groove formed in the above, so that the sealing material can be prevented from flowing into the through hole.

Therefore, the sealability can be secured without impairing the clearance.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. The same elements as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted. The valve shaft 16 is made of bearing steel, and is provided with peripheral grooves 1 and 5 so that the outer peripheral side surfaces 2 and 6 of the partition wall 13 are aligned with the partition wall surface 13b of the partition wall 13.

It is to be noted that the intake air flows in the two intake passages 11 and 12 from the upper side to the lower side in the figure as indicated by an arrow F, and the circumferential grooves 1 and 5 are as shown in FIG. Only the downstream side 16a in the flow direction, which is the negative pressure side, is provided within the range of the maximum central angle of 160 ° with respect to the flow direction. Also, molybdenum 25 as a sealing material is applied in a liquid state around the valve shaft 16 on the outer side of the outer peripheral side surfaces 2 and 6 along the peripheral grooves 1 and 5 with a brush so as to be dried and solidified. There is.

Here, even if the molybdenum 25 applied along the circumferential grooves 1 and 5 flows on the surface of the valve shaft 16 until it dries, the valve shaft 16 is a side that is bent by the influence of negative pressure. Since the circumferential grooves 1 and 5 are provided on the downstream side 16a in the flow direction within the range of the maximum central angle of 160 °, molybdenum 25 is stored in the circumferential grooves 1 and 5 (reservoir portion is indicated by 26). It is possible to prevent the rib den 25 from flowing into the side 16a where the valve shaft 16 in the through hole 13a bends.

The distance A in the drawing is 200 to 250 μm, the distance B in the drawing is A / 3 to A / 2, and the deviation of the valve shaft 16 due to the bending is about 100 μm. Here, on the side opposite to the downstream side 16a in the flow direction of the valve shaft 16, even if molybdenum 25 flows in, it is not affected by the bending, so the valve shaft 16 does not interfere with the partition wall 13. .. Therefore, the circumferential grooves 1 and 5 do not have to be provided all around.

As described above, according to the present embodiment, the sealing property (molybdenum 25) can secure the sealing property, and the circumferential grooves 1 and 5 can prevent the sealing material from bending due to the influence of negative pressure. Since it is possible to avoid the inflow, the predetermined clearance is not impaired, and thus it is possible to prevent the valve shaft 16 from interfering with the partition wall 13.

[0015]

[Effect of the device]

 As described above, according to the present invention, it is possible to maintain the sealing property and prevent the seal material from flowing into the through hole on the side where the valve shaft bends due to the influence of the negative pressure due to the circumferential groove. Even if the valve shaft bends under pressure, a predetermined clearance is secured, and it is possible to avoid interference with the partition wall.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of part J in FIG.

FIG. 3 is a sectional view taken along line MM in FIG.

FIG. 4 is a sectional view showing a conventional example.

FIG. 5 is a sectional view showing a conventional problem.

[Explanation of symbols]

 1 circumferential groove 2 outer circumferential side surface 5 circumferential groove 6 outer circumferential side surface 11 intake passage 12 intake passage 13 partition wall 13a through port 13b partition wall surface 14 throttle valve 15 throttle valve 16 valve shaft 25 molybdenum

Claims (1)

[Claims for utility model registration] [Claim 1] A valve shaft of a throttle valve for each intake passage is provided coaxially through a through hole formed in a partition wall between two intake passages arranged in parallel. In the intake device of an internal combustion engine, both ends of which are rotatably held in the intake passage wall portion via bearings, a circumferential groove is formed around the valve shaft that is directly inside the partition wall and faces at least the negative pressure side. In addition, an intake device for an internal combustion engine, characterized in that a sealing material is applied around the valve shaft outside the peripheral groove along each peripheral groove.