JPS6124651Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a cooling device for intake and exhaust valve seats of an internal combustion engine.

In recent years, the output per cylinder of internal combustion engines has increased, and at the same time the heat load on the combustion chamber within the engine cylinder has increased.In particular, the heat load on the intake and exhaust valve seats, which come into contact with high-temperature exhaust gas during operation, has increased. This causes problems such as leakage and burnout, resulting in reduced durability. Therefore, it is necessary to cool the intake and exhaust valve seats to lower their temperature and improve their durability.

Conventionally, intake and exhaust valve seat cooling devices that are directly inserted and fixed into the cylinder head have grooves on the outer periphery of the valve seat 2, which is fitted and fixed into the cylinder head 1, as shown in Fig. An annular passage 3 is formed between them, and the passage 3 communicates with the jacket part 4 of the cylinder head through a passage 5, so that the cooling water in the jacket part 4 flows into the annular passage 3 of the valve seat 2. ing. In such a system, the cooling water remains in the annular passage 3 of the valve seat 2 and rarely flows, making it impossible to uniformly and effectively cool the valve seat. In addition, since the outer circumferential surfaces 7 and 8 of the valve seat 2 fitted into the cylinder head 1 form a seal for cooling water, in the event that water leaks from the seal, the leak may enter the cylinder, creating a dangerous situation. state. Furthermore, when assembling or replacing the valve seat, there are manufacturing problems such as difficulty in controlling the dimensions of the interference of the fitting portion to ensure water sealing.

This idea was made in view of the above, and it not only uniformly cools the intake and exhaust valve seats, but also improves the cooling effect, is safe against leakage of the cooling water seal, and is easy to assemble or replace. The purpose of this invention is to provide a cooling device for an exhaust valve seat.

An embodiment of this invention will be described below with reference to FIGS. 2 and 3.

In the drawings, 10 is a cylinder head of an internal combustion engine, and 11 is an intake/exhaust valve seat that is pushed into and fixed to the cylinder head 10 and has an annular passage 12 for circulating cooling water formed therein. A cooling fluid inlet pipe 13 having a passing passage 13a therethrough and a cooling fluid outlet pipe 14 having a passing passage 14a are connected to the intake and exhaust valve seat 11 from the side wall of the cylinder head 10.
The cylinder head 10 is inserted into two parallel parallel through holes 15 and 16 that are opened approximately horizontally up to the outer periphery of the cylinder head 10, with gaps 15a and 16a provided between the through holes, respectively, and the inner end on the insertion side. Part 13b, 1
4b is screwed and fixed to the intake/exhaust valve seat 11,
The passages 13a and 14a communicate with the annular passage 12.

Pipe joints 17 and 18 are provided at the outer end openings of the cooling fluid inlet pipe 13 and the cooling fluid outlet pipe 14, respectively, and branch pipes 21 of the main cooling fluid inlet pipe 19 of the engine are provided.
is connected to the pipe joint 17, and the cooling fluid outlet main pipe 20
A branch pipe 22 is connected to the pipe joint 18.

The cooling fluid inlet pipe 13 and the cooling fluid outlet pipe 14
A partition pin (partition member) 1 is provided in the annular passage 12 of the intake/exhaust valve seat 11 at an intermediate position between the inner ends 13b and 14b so as to partition the annular passage 12.
2a is fitted (FIG. 3), and the cooling fluid inlet pipe 1 is inserted near one side of the partition pin 12a.
3, the cooling fluid flows into the inner end 1 of the passage 13a.
3'a flows in the direction of the arrow in Figure 3, and the annular passage 1
2 is circulated and flows into the inner end of the passage 14a of the cooling fluid outlet pipe 14 near the other side of the partition pin 12a. Note that 25 is a valve mounted on the cylinder head.

This device is constructed as described above, and during operation of the internal combustion engine, cooling fluid is taken in and exhausted from the main cooling fluid inlet pipe 19 via the branch pipe 21 and the cooling fluid inlet pipe 13 from the inner end 13'a of the passage 13a. It enters the annular passage 12 of the valve seat 11, circulates through the annular passage 12 to cool the intake/exhaust valve seat 11, passes through the passage 14a of the cooling fluid outlet pipe 14, and enters the cooling fluid outlet main pipe 20 via the branch pipe 22. Reflux.

That is, since the cooling fluid is cooled while circulating in one direction through the annular passage 12 provided inside the intake/exhaust valve seat 11, the valve seat 11 is cooled uniformly, and the amount and temperature of the cooling fluid to be supplied are controlled. By doing so,
The cooling effect of the valve seat 11 can be enhanced.

Also, an inner end portion 13b, which is a connection portion of the cooling fluid inlet pipe 13 and the cooling fluid outlet pipe 14 to the valve seat 11;
Even if water leaks from the cylinder head 14b, the water leaks through the through holes 15, 16 of the cylinder head 10 and the respective pipes 13, 1.
It is discharged to the outside through the gaps 15a, 16a with respect to the cylinder 4, and there is no risk of it entering the cylinder.

As explained above, in the intake/exhaust valve seat cooling device of this invention, the valve seat, which has an annular cooling fluid passage with a partition member inside, is pushed into the cylinder head and fixed, and an approximately horizontal hole is opened in the cylinder head. ,
inserting a cooling fluid inlet pipe and an outlet pipe into a pair of through holes to the valve seat with a gap provided therebetween;
One end of each of these is connected and communicated with the annular passage near both sides of the partition member, so that the cooling fluid is circulated in one direction through the annular passage.
By uniformly cooling the intake and exhaust valve seats, and by controlling the amount and temperature of the cooling fluid supplied, the cooling effect of the valve seats can be enhanced. Even if there is a leak, it can be easily drained to the outside through the through hole in the cylinder head.
It is safe as there is no danger of getting inside the cylinder. Also,
Since there is no need to consider the water seal at the fitting portion between the valve seat and the cylinder head, there are advantages such as ease of assembling or replacing the valve seat.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main part of a conventional intake/exhaust valve cooling device, Figs. 2 and 3 are drawings showing an embodiment of the present invention, Fig. 2 is a sectional view of the main part, and Fig. A- in Figure 2
It is an A sectional view. 10... Cylinder head, 11... Intake/exhaust valve seat, 12... Annular passage, 12a... Partition pin,
13...Cooling fluid inlet pipe, 14...Cooling fluid outlet pipe, 15, 16...Through hole, 15a, 16a...
gap.

Claims (1)

[Scope of utility model registration request] In an intake/exhaust valve seat of a type in which the valve seat is pushed and fixed into a cylinder head of an internal combustion engine, the valve seat is provided with an annular passage for cooling fluid having a partition member inside;
A pair of through holes are formed in the cylinder head so as to penetrate approximately horizontally from the side wall of the cylinder head to the fitting opening of the valve seat, and the valve is inserted into the pair of through holes with a gap provided therebetween, and a cooling fluid inlet pipe and a cooling fluid outlet pipe each having one end connected to the annular passage of the valve seat near both ends of the partition member and the other end respectively connected to a cooling fluid supply source; A cooling device for intake and exhaust valve seats characterized by the following.