JPS5838310A - Suction valve and exhaust valve of internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable to decrease temperature at a seat part of a valve and to enable to improve wear resistance, by a method wherein a sheet number, being harder than a valve parent material, is attached to the total peripheral surface of the seat part of the valve, and a gap is formed in an interface part between the sheet member and the valve parent material. CONSTITUTION:A sheet member 14 formed of a material such as stelite being harder than a valve parent material is attached to a total peripheral surface of a sheet part 13 of a conical part 12 of a valve. In front and rear adhesion parts A and B in a direction of width at the peripheral surface of the sheet part 13, a gap is formed between the adhestion parts A and B and in an interface part between the sheet member 14 and the valve parent material. A heat insulating action, caused by the gap 19 in the interface part between the sheet member 14 and the valve parent material, sharply reduces thermal conduction to the sheet member 14 from a conical part 12 and the sheet part 13 which are positioned at a valve side and influenced by high temperature of combustion gas. Additionally, the sheet member 14 is efficiently cooled through the medium of a sheet member 7 by cooling water in a cooling hole in an exhaust valve seat (b).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention maintains the temperature of the seat portion of an intake and exhaust valve of an internal combustion engine at a low temperature, and improves the wear resistance and corrosion resistance of the core portion.

A conventional example of an exhaust valve for an internal combustion engine will be explained.

As shown in Figure 1, the exhaust valve (a) is exposed to high temperature and high pressure combustion gas (exhaust gas) and is in a high temperature and highly corrosive environment, and its seat part (3) is the exhaust valve seat (b). The seat part (7) of
Therefore, the seat part (31) of the exhaust valve (a) is generally required to be made of a material with corrosion resistance and abrasion resistance, and the material is better than the material of the valve base material (stem part (1), umbrella part (2)). A sheet member (4) made of hard Stellite or the like is also overlaid.

By the way, in the exhaust valve of an internal combustion engine, the sheet member (4) becomes hotter than the combustion gas (exhaust gas) K during high-load operation of one engine, and its hardness decreases.

Wear resistance and corrosion resistance decrease, and the exhaust valve seat (b
) When sitting on the seat part (7)k, impurities (combustion residue) mixed in the fuel are likely to bite into the seat surface (4') and create an impression (dent). If the sheet member (4) continues in the width direction (arrow direction (force direction)), combustion gas will blow through the gap created by the impression when the valve is seated, and the airtightness of the valve will be impaired. In valve (a).

In addition to using hard Stellite etc. as the seat member (4), the exhaust valve seat (b) K is provided with a cooling hole (6).
) Pass the cooling water through the seat part (7) of the exhaust valve seat (b).
1, the temperature of the seat member (4) of the exhaust valve (a) is lowered to prevent a decrease in its hardness.
Due to the heat conduction from 2), the cooling effect of the sheet member (4) cannot be expected to be very great.

Furthermore, as internal combustion engines have recently become more powerful, the heat load on the combustion chamber has increased, and combustion residues have also tended to increase due to the deterioration of fuel oil.

Seat surface (4') of seat member (4) of exhaust valve (a)
The above-mentioned blow-throughs are becoming more likely to occur, and measures to prevent them are needed. Intake valves that are affected by combustion gas also have the same difficulties as the exhaust valves described above, and require similar countermeasures.

The present invention solves the above-mentioned difficulties in conventional intake/exhaust valves for internal combustion engines. At the boundary between the valve base material and the valve base material! 2
! It is characterized by the provision of a gap, and its purpose is to reduce the temperature at the valve seat and improve wear resistance.

An object of the present invention is to provide an intake/exhaust valve for an internal combustion engine with improved corrosion resistance.

The present invention has the above-described structure, and the high temperature of combustion gas (exhaust gas) is reduced by the heat insulating effect of the gap provided at the boundary between the seat member attached over the entire circumference of the seat portion of the valve and the valve base material. Heat conduction from the extension side umbrella section and seat section to the seat member, which is widely affected by 8# IC, is significantly reduced, so the seat member is kept at a low temperature by cooling from the valve seat, and The hardness is maintained and its wear resistance and corrosion resistance tl prevents blow-through when the valve is seated and significantly improves durability.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 2 shows the 111E1 embodiment of the present invention, and in Figure 1 (13
is the cap part of the exhaust valve, a: 4 is the seat part around the cap part a20, (141 is the seat part (made of a material such as stellite that is harder than the valve base material (seat part a3) installed over the entire circumference of 13) (14') is the seat surface of the seat member I, (b) is the exhaust valve seat, (6) is the cooling hole provided in the exhaust valve seat (b) through which cooling water passes, (7)
is the seat member of the exhaust valve seat (b) in this first embodiment.

The sheet member (14) is attached with adhesive at the front and rear (c) adhesive parts in the width direction (in the direction of the arrow in Fig. 1) on the circumferential surface of the sheet part a3, and the adhesive part (A) and (
6), a void II (19) is provided at the boundary between the seat member (14) and the valve base material, that is, the seat portion a3.

Although the above-mentioned cavity 11al is formed in a ring shape surrounding the entire circumferential surface of the seat portion (13) in the first drawing, it can also be formed by arranging a plurality of short grooves in one row.

Furthermore, in the case of the adhesive part (Al and (B) K) between the valve seat part 0 and the seat member a bottle, the (A) 41 adhesion part is closer to the combustion chamber side, that is, the contact surface, than the (B) adhesive part, and the temperature is high. To achieve this, (A) the adhesive area of the adhesive part is made smaller than the adhesive part, and (A) the thickness of the sheet member I on the adhesive part side is significantly increased to achieve a more effective temperature. I'm trying to lower it.

The first embodiment shown in FIG. 2 is configured as described above, and the boundary between the seat member I, which is attached over the entire circumferential surface of the exhaust valve seat portion (13), and the valve base member seat portion 0. Due to the heat insulating effect of the empty WaS provided in the
B. Since the heat conduction from the seat part a3 to the seat member I is limited to the bonded parts (A) and (B) and is greatly reduced, the cooling in the cooling hole (6) of the exhaust valve seat (b) is reduced. By cooling with water, the sheet member 4 is efficiently cooled via the sheet member (71).

The temperature of the seat member α4 of the exhaust valve is significantly reduced and kept at a low temperature, and the hardness and wear resistance of the seat member Q4 are improved.

Corrosion resistance is also maintained sufficiently, and the impression (dent) of the sheet member α fathom sea) 1i1F (14') as described above is maintained.
There is almost no leakage, and combustion gas can be prevented from blowing through when the valve is seated. Therefore, the durability of the sheet member is improved.

Further, FIG. 6 shows a second embodiment of the present invention, and in FIG. 1, a is the umbrella part of the exhaust valve, a3 is the seat part, α bump is the seat member, (b) is the exhaust valve seat, (6) (7) is the cooling hole, and (7) is the same sheet member, which has the same structure as the first embodiment, and there is a hole at the boundary between the sheet portion 0 and the sheet member a4 attached to its entire circumference. A plurality of voids l1(2),(2)0.
Although this configuration is different from that of the first embodiment, the effect due to the empty 5t(21, (to)...k can be expected to be almost the same as that of the first embodiment, and this In the case of the example, there are several adhesive parts (Q
(C)... is possible, so that the sheet member α fathom becomes the seat part f
+It is installed more strongly than Q311c.

In the above embodiment, the exhaust valve was explained, but the intake valve has a substantially similar structure and the same effect can be obtained.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design changes can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a conventional example of an internal combustion engine exhaust valve, and FIG. 2 is a partial vertical sectional view showing a first embodiment of the present invention.
FIG. 3 is a partial vertical sectional view showing the second embodiment. a: Exhaust valve b: Exhaust valve seat 12: Umbrella portion 13: Seat portion 14: Seat member 14': Seat surface 19.2
0: void A, B: W! Sub-agents: Patent attorneys and 2 non-Kaihon important authors

Claims (1)

[Claims] A seat member that is harder than the valve base material is installed over the entire circumference of the valve seat portion, and at the boundary between the seat member and the valve base material! 2! An intake-exhaust valve for an internal combustion engine characterized by having a gap.