JPS59108810A - Exhaust valve device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To cool the radiating end of heat pipe smoothly without disturbing operation by coupling between supply and discharge devices of fluid for cooling an exhaust valve and a valve shaft through a telescopic tube. CONSTITUTION:An exhaust valve is provided with a heat receiving section on a bevel section 5 where the radiating section is cooled by a heat pipe 7 to be arranged on a shaft section 6. An opening 23 of the shaft section 6 is closed by a telescopic tube 25 provided rotatably and reciprocally against the shaft section 6 to form a heat exchange chamber 15 around the heat pipe 7. Coolant feed path 26 and discharge path 27 having check valves 34, 35 are coupled to the heat exchange chamber 15 to feed/discharge fluid through expansion/shrinkage of heat exchange chamber 15 based on reciprocation of valve. Because of said telescopic tube 25, reciprocation/rotation and feed/discharge of coolant can be performed smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust valve device for an internal combustion engine that is equipped with a heat pipe for cooling the valve head side exposed to a high-temperature atmosphere, and particularly relates to an exhaust valve device for an internal combustion engine that is equipped with a heat pipe to cool the valve head side exposed to a high temperature atmosphere. The present invention relates to an exhaust valve device for an internal combustion engine that can smoothly cool the heat radiation side of a heat pipe, fully utilize the function of the heat pipe, and improve the durability of the exhaust valve.

The exhaust valve of an internal combustion engine, especially the valve head and the valve stem connected to it, are exposed to high-temperature atmosphere (
Because it is exposed to combustion gas), it is susceptible to damage such as deterioration of material strength and vanadium corrosion (occurs at temperatures above 550'C). In order to solve this problem, it has been considered to cool the exhaust valve itself, and various cooling-type exhaust valve structures have been devised. However, if it is cooled too much, a problem arises in that sulfuric acid corrosion (occurs at approximately 220° C.) occurs. From the above, the exhaust valve should be operated at an angle of 80°C to 440°C, with the valve head side exposed to high temperature atmosphere omitted.
It is considered optimal to maintain cooling in a temperature range of about 100 ℃.

Taking into account the above-mentioned conditions, the inventor of the present application previously disclosed in Utility Application No. 48-96531 that a heat pipe containing a refrigerant is built into the exhaust valve, and a heat receiving end is formed on the side of the valve head that is heated. This system is designed to cool the exhaust valve by transporting heat from the exhaust valve to a heat dissipation end formed on the valve stem side, and supplying a coolant such as water to this heat dissipation end in accordance with the increase in the amount of heat transport. The above problem was solved by proposing an umbrella-shaped valve.

By the way, when the exhaust valve according to the above invention is applied to a specific internal combustion engine, the exhaust valve opens and closes the exhaust port by reciprocating a valve head seated on a valve seat formed along the exhaust port. In order to improve the airtightness of the exhaust port, the valve head is driven reciprocally in the axial direction and rotated around the axis to rotate the valve head over the valve seat to improve the airtightness of the exhaust port. There has been a demand for a structure that can supply coolant to the heat radiation side of the heat pipe without interfering with valve operation, and that can fully utilize the functions of the heat pipe.

The present invention was devised in view of the above-mentioned circumstances, and its purpose is to
To provide an exhaust valve device for an internal combustion engine that can smoothly cool the heat radiation side of a heat pipe, fully exhibit the function of the heat pipe, and improve the durability of the exhaust valve.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, an exhaust valve 1 is inserted through the cylinder head 2 so as to be able to reciprocate along the axial direction of the cylinder head 2 and to be rotatable around the axis. This exhaust valve 1 includes an umbrella-like valve umbrella part 5 with an enlarged diameter that sits on a valve seat part 4 formed along the circumferential direction of the exhaust port 3, and a shaft-like valve umbrella part 5 integrally connected to the valve umbrella part 5. When the valve stem 6 is reciprocated, the valve head 5 moves away from the exhaust port 3 to open and close it, and the valve stem 6 is rotationally driven. As a result, it is configured to rotate along the valve seat portion 4 to ensure a high sealing degree when the exhaust port 3 is closed.

The exhaust valve 1 configured in this way has a hollow interior that follows the outer shape, and a valve umbrella that is heated by being exposed to a high temperature atmosphere along the axial direction is provided inside the valve stem 6. A heat pipe 7 is provided which recovers heat from the valve stem portion 6 side and radiates the heat from the valve stem portion 6 side. The lower end of the heat pipe 7 is open facing the hollow chamber 8 formed by expanding the diameter inside the valve head portion 5, and the upper end extending toward the valve stem end 9 on the opposite side is capped. A series of closed hollow chambers are formed by the pipe material 11 closed at 10, and a refrigerant C such as water for heat transport is sealed inside the hollow chambers. The pipe material 11 has an annular upper mounting wall 12 and a lower mounting wall 13, which are formed at a predetermined interval along the axial direction and extend outward in the radial direction, and are welded to the valve stem inner wall 14. It is fixed by welding. In particular, the upper mounting wall 12 divides the inside of the valve stem 6 in the axial direction and connects the heat pipe 7 with a heat receiving end (valve head side portion) A exposed to a high temperature atmosphere (exhaust gas, etc.) and a cooling end (portion on the valve head side) which will be described later. A heat dissipating end (valve stem side portion) B cooled by the material F is formed, and the heat dissipating end B side forms the bottom wall of a heat exchange chamber 15, which will be described later, and a heat receiving end A
It has a function of forming a hollow heat insulating wall 16 with air or the like between it and the lower mounting wall 13 on the side. That is, the heat pipe 7 has a series of heat dissipating ends B engraved from the upper end toward the valve head portion 5 side, and is surrounded by the upper mounting wall 12 and held with high strength, and has an enlarged diameter portion 17 that is enlarged in diameter in different steps. A heat receiving end A is formed on the valve head portion 5 side below the heat receiving end A.

In the heat pipe 7, the refrigerant C remains in a liquefied state at the heat receiving end A, and when the heat receiving end A is exposed to a high temperature atmosphere and heated, it vaporizes and reaches the heat radiating end B.
It is configured to repeat a cooling cycle in which it is cooled down, turned into droplets, and collected again to the heat receiving end A.

In addition, in the hollow chamber 8 of the valve head part 5, a circulation groove 18 is formed radially in the radial direction thereof, and a circulation hole 19 is formed in an annular shape along the circumferential direction. It is configured to efficiently cool the entire umbrella portion 5, especially the seating portion 2o seated on the valve seat portion 4, and the umbrella surface portion 21 has a large number of holes in order to increase the cooling surface area while ensuring its strength. A recess 22 is formed.

By the way, a feature of the present invention (a) is that the coolant F is smoothly supplied to the heat dissipation end B of the heat pipe 7 to the exhaust valve 1 having the heat pipe 7 as described above without interfering with the reciprocating movement and rotation of the entire exhaust valve 1. This is because we have equipment that can do this.

As shown in the figure, within the valve shaft portion 6 of the exhaust valve 1, there is heat for cooling the vaporized refrigerant C that surrounds the heat dissipation end B of the heat pipe 7 along its axial direction and rises and stays inside. An exchange room 15 is formed.

The heat exchange chamber 15 is formed in a cylindrical shape between the valve stem inner wall 14 and the heat dissipation end B, and its bottom is partitioned by the upper mounting wall 12, and the top has a valve stem end 9. is opened to form an opening 23.

The heat exchange chamber 15 includes a hollow cylindrical nesting tube 25 whose upper end is closed with a lid 24 to close the opening 23.
is provided. The upper end of the nested tube 25 extending outward from the valve stem end 9 is supported by a fixed side 28 via a supply passage 26 and a discharge passage 27, which will be described later, to prevent rotation and keep it in a predetermined position. Fixed. On the other hand, the lower end of the nested tube 25 is inserted deeper into the heat exchange chamber 15 than the reciprocating stroke length of the exhaust valve 1 . The nested tube 25 has its outer peripheral wall in sliding contact with the inner wall 14 of the valve stem, and allows the valve stem 6 to reciprocate in the axial direction and rotate around the axis without moving itself. It is configured as follows. Further, on the outer peripheral wall of the nested tube 25, there is an O-IJ ring 29 having heat resistance, wear resistance, and corrosion resistance to prevent the coolant F from leaking from the sliding surface with the valve stem inner wall 14. It is installed as appropriate.

In order to partition the inside of the heat exchange chamber 15 and form a flow path for a coolant F such as water, steam, air, lubricating oil, etc., a heat dissipation end B is placed in the radial direction of the nested tube 25 in its axial direction. A tubular partition wall 30 is provided along and surrounding the wall. This partition wall 30 is
Its upper end is joined to the lid 24 and closed, and its lower end is opened to form a continuous flow path 31 from the inside to the outside. A supply passage 26 and a discharge passage 27 made of tubular bodies are connected to the flow passage 31 in order to supply and discharge the coolant F into the heat exchange chamber 15 . Specifically, the supply passage 26 and the discharge passage 27 are fixedly fitted into the supply port 32 and the discharge port 33 formed in the lid body 24 that closes the upper end of the nested tube 25. This arrangement allows the coolant F to be supplied and discharged regardless of the rotation and reciprocation of the valve stem 6.

A check valve 34, 35 is interposed in the supply passage 26 and the discharge passage 27. These check valves 34 and 35 prevent the coolant F from flowing backwards due to the pumping action that occurs when the inside of the heat exchange chamber 15 expands and contracts when the valve shaft portion 6 reciprocates, thereby supplying and discharging the coolant F. While maintaining the coolant F in one direction, the pump action actively flows the coolant F into the heat exchange chamber 15.
is configured to supply and discharge.

As shown in the figure, a holding fitting 37 is provided on the valve stem end 9 to cover the lid 24 and the like along the axial direction on an annular member 36 screwed thereto.

This presser metal fitting 37 has a ball bearing 38 interposed between it and the annular member 36 to cut off mutual rotation, and has a concave seat 39 at its upper end. In order to reciprocate the shaft portion 6, a hydraulic bushing rod 40 is inserted which is moved up and down by a known hydraulic device (not shown). Therefore, the operating force of the hydraulic bushing rod 40 (7), which is driven downward during the exhaust stroke in synchronization with the rotation of the internal combustion engine, is applied to the valve via the holding fitting 37, the ball bearing 38, and the annular member 36 along the axial direction. It will be transmitted to the shaft end 9. Further, although the valve shaft portion 6 is directly rotated by a known rotating device (not shown), the rotation is configured such that the rotation does not extend to the presser fitting 37 side by the ball bearing 38. As shown in FIGS. 1 and 2, this presser fitting 37 has a through hole 41 through which the supply passage 26 and discharge passage 27 are gently guided.
is formed in the shape of a long hole along the reciprocating direction.

A housing 42 that covers the entire valve stem end 9 side is provided radially outward of the presser fitting 3T that is reciprocated. The housing 42 has its base end fixed to the cylinder head 2, and its top tip surrounds the upper end of the presser metal fitting 37 in the radial direction. Groove 43 carved along the reciprocating direction
A ball bearing 44, which functions as a key member, is interposed between the presser fittings 37 to allow only the reciprocating movement of the presser metal fitting 37, and to restrict its rotation.

This housing 42 supports and penetrates the supply passage 26 and the discharge passage 2T, fixedly supports the feed passage 25 at a predetermined position from the cylinder head 2 side through these, and prevents its rotation. The fixed side 28 is configured.

Note that 45 is a vibration-proof rubber provided in a portion where the supply passage 26 and the discharge passage 27 pass through the housing 42, and is used to buffer vibrations caused by the operation of the valve stem portion 6. Also, 46
is provided in an annular shape extending from the valve stem end 9 to the annular member 36, and is heat-resistant, wear-resistant, and corrosion-resistant to prevent the coolant F from leaking from the sliding contact area between these and the annular member 36. It is a waterproof rubber with Further, 47 is an air vent hole, and 48 is a valve box. In addition, the supply passage 26 and the discharge passage 27
constitutes a circulation path via a heat exchanger, etc. (not shown). Furthermore, the valve shaft portion 6 is configured to be returned upward by a known air spring, hydraulic cylinder, etc. (not shown) to close the exhaust port 3.

The operation of the above configuration will be described.

When the internal combustion engine is operated, the exhaust valve 1 reciprocates while its valve stem 6 is rotated to open and close the exhaust port 3 to allow the high temperature atmosphere generated by combustion to flow out from the combustion chamber to the exhaust system. . On the side of the valve head part 5 that is exposed to this high-temperature atmosphere and heated, the refrigerant C retained at the heat receiving end A of the heat pipe 7 is heated, recovers the heat, vaporizes it, and rises to the heat radiation end B. As a result, it is cooled by the coolant F flowing inside the heat exchange chamber 15.

Coolant F is supplied to the heat exchange chamber 15 from a supply passage 26 . The coolant F flows down from the supply port 32 into the partition wall 30 and immediately cools the heat dissipation end B of the heat pipe 7. The coolant F flowing down between the heat dissipating end B and the partition wall 30 is reversed at the bottom of the heat exchange chamber 15, and is then transferred to the outside of the partition wall 30 and the inner wall 14 of the valve stem, and further flows to the outside of the partition wall 30 and the inner wall 14 of the valve shaft portion. It reaches the discharge port 33 via the discharge port 33 and flows out into the discharge passage 27.

By the way, at this time, the valve stem portion 6 is being rotated and reciprocated. In this device, the valve stem 6 is provided between the supply passage 26 and the discharge passage 27 for supplying and discharging the coolant F, and the valve stem 6 to be operated, allowing reciprocating and rotation of the valve stem 6. Exhaust valve 1 was removed due to the interposition of AM 25 to cut off the movement.
The supply passage 2 is fixedly provided without interfering with the operation of the
When the coolant F is smoothly supplied and discharged from 6 and the discharge passage 27, 7 is obtained. In addition, in this example, as a peripheral structure,
Since a ball bearing 38 is interposed between a presser fitting 37 that is driven to reciprocate the exhaust valve 1 and an annular member 36 that is integrally provided at the end 9 of the valve stem, the valve stem 6 is not transmitted to the presser fitting 37 that penetrates the supply passage 26 and the discharge passage 27. In addition, the presser metal fitting 37
Although its rotation is restrained by the nozzle housing 42 via a ball bearing 44 which is a key member, and the valve shaft portion 6 is driven to reciprocate, the supply passage 26 and the discharge passage 27 are not penetrated. Since the through hole 41 is formed in the shape of a long hole along the reciprocating direction, its operation is not hindered.

In this way, this device can smoothly supply the coolant F to the heat dissipation end B of the heat pipe 7 without interfering with the operation of the exhaust valve 1, so that the function of the heat pipe 7 can be fully demonstrated. By maintaining the exhaust valve 1 within a predetermined temperature range, strength deterioration, vanadium corrosion, sulfuric acid corrosion, etc. can be suppressed, and its durability can be improved.

In addition, in this device, by allowing the reciprocating movement of the valve stem 6 during the opening 25, the heat exchange chamber 15 can be expanded and contracted to exert a pumping action, and the coolant F can be efficiently pumped.
can be supplied and discharged.

In summary, the present invention exhibits the following excellent effects.

(1) A supply passage and an exhaust passage that are fixedly provided to supply and discharge coolant to a heat exchange chamber that is formed in the valve stem of the exhaust valve and that cools the heat radiation end of the heat pipe, and that rotate and reciprocate. Since the valve shaft portion to be moved is connected to the valve stem portion by a nested tube that cuts off the valve operation, the heat radiation end of the heat pipe can be smoothly cooled without interfering with the operation of the exhaust valve.

(2) Therefore, the heat pipe can fully demonstrate its function, and the durability of the exhaust valve can be improved as much as possible.

(3) Check valves installed in the supply passage and discharge passage allow
By actively utilizing the pumping action based on the expansion and contraction of the heat exchange chamber due to the relative movement between the nested tube and the valve stem, the coolant can be efficiently supplied and discharged.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a preferred embodiment of the present invention, and FIG. 2 is an enlarged front view of the main parts thereof. In the figure, 3 is an exhaust port, 4 is a valve seat part, 5 is a valve head part, 6 is a valve stem part, 9 is its end part, 7 is a heat pipe, 15 is a heat exchange chamber, 23 is its opening, 25 26 is a nested tube, 26 is a supply passage, 27 is a discharge passage, 28 is a fixed side, 34.35 is a check valve, A is a heat receiving end of the heat pipe, B is its heat radiation end, and F is a coolant. Patent Applicant: Nobuo Kinutani, Patent Attorney, Ishikawajima-Harima Heavy Industries Co., Ltd.

Claims (1)

[Claims] A valve head part that seats on a valve seat part formed in an exhaust port, and a valve shaft part that rotates the valve head part along the valve seat part and moves it away from the valve seat part to open and close the valve head part. In the exhaust valve for an internal combustion engine, the heat pipe is provided along the valve stem and forms a heat receiving end in the valve head and a heat dissipating end in the valve stem, and an end of the valve stem. a heat exchange chamber that surrounds and cools the heat dissipation end of the heat pipe along the valve stem; A nested tube supported from a fixed side to allow reciprocating movement in the axial direction and rotation in the circumferential direction, and a supply passage provided in the nested tube for supplying a coolant into the heat exchange chamber. The heat exchanger chamber includes a discharge passage for discharging the coolant, and a check valve for supplying and discharging the coolant from the heat exchange chamber, which is provided in each of these passages and expands and contracts when the valve stem moves back and forth. Features: Exhaust valve device for internal combustion engines.