JPH0512590B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a poppet valve device, and more particularly to a poppet valve drive device that allows the poppet valve to sit on a valve seat without impact, thereby improving the durability of the valve device.

[Prior Art] Poppet valve devices are widely used as valve devices for appropriately controlling the opening and closing of intake and exhaust passages formed in compressors, internal combustion engines, high-pressure gas furnaces, and the like.

This poppet valve device uses a cam mechanism or a hydraulic mechanism to open and close the poppet valve.

[Problems to be Solved by the Invention] However, when the poppet valve is seated on the valve seat, a large impact force is generated between them, resulting in scratches on the valve seat surface and frequent damage to the poppet valve device. It has been known. When opening and closing the poppet valve using a cam mechanism to buffer this impact force, it is important to form the cam in a shape that decelerates the poppet valve when it attempts to sit. This has not been realized as it would lead to larger size.

Further, in the hydraulic valve mechanism, the device is complicated and expensive, and the working fluid used in the hydraulic device is an incompressible fluid, so that a sufficient effect cannot be obtained against the above-mentioned impact force.

For this reason, ceramics with excellent properties cannot be used for the poppet valve, valve seat, etc., and it has become difficult to design their weight reduction and cooling shape.

[Summary of the Invention] In order to achieve the above object, the present invention includes a poppet valve that is seated on a valve seat to open and close the poppet valve, and a valve stem of the poppet valve that is slidably guided to the valve seat. a guide cylinder, a movable cylinder that is movably provided along the guide cylinder, forms a pressure chamber with the guide cylinder, and is connected to the valve stem; a valve opening device for moving the poppet valve connected to the valve in the valve opening direction; and a fluid supply means provided for supplying working fluid into the pressure chamber to move the poppet valve in the valve closing direction;
A pressure adjusting means is provided for adjusting the fluid pressure from the fluid supply means to the pressure chamber, and is provided so that the poppet valve is cushioned and seated on the valve seat. Specifically, a poppet valve is provided. In order to prevent the fluid from sitting on the valve seat with an impact force, the supply of working fluid from the fluid supply device to the pressure chamber is temporarily stopped, or the supply amount is released to, for example, a turbine. The movable cylinder and the poppet valve are seated on the valve seat without shock only by inertia force, and then the pressure regulating means is supplied or increased again to tightly engage the valve seat.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to the accompanying drawings showing an example of an internal combustion engine for a ship or the like.

In order to cushion and seat the valve on the valve seat provided in the intake and exhaust passages formed from the cylinder head to the combustion chamber, the cylinder head 1 has a valve seat provided in the direction of opening and closing the intake and exhaust passages 2, as shown in FIG. poppet valve 3
A guide tube 5 is provided to slidably guide the valve stem 4 of the valve. One end 6 of the valve rod 4 is accommodated in a cylindrical moving cylinder 7 that is fitted in a movable manner along the guide tube 5, and is integrally connected thereto. On the other hand, by fitting the guide cylinder 5 and the movable cylinder 7, a pressure chamber 8 is formed inside them, and by supplying air or compressible working fluid to the pressure chamber 8, the movable cylinder 7 and a poppet valve 3 connected thereto are configured to always urge the valve seat 9 in the valve closing direction. On the other hand, in order to separate the poppet valve 3 from the valve seat 9 and open the suction/exhaust passage 2, a valve opening device is provided on the bottom surface 10 of the movable cylinder 7, which is formed of a cylinder 12 having, for example, a piston 11 slidably installed therein. 1
3 is provided, which is configured to overcome the working fluid pressure in the pressure chamber 8 and bias the moving cylinder 7 and the poppet valve 3 to operate them. Further, the fluid supply means 17 and the pressure adjustment means 20 which allow the poppet valve 3 to sit on the valve seat 9 without any impact force and supply working fluid to the pressure chamber 8 will be specifically explained.

A fluid supply means 17 for supplying working fluid to the pressure chamber 8 is provided in the guide cylinder 5, and communicates fluid in a direction crossing the guide hole 14 that slidably guides the valve stem 4 of the poppet valve 3. It is composed of a passage 15 and a fluid introduction passage 16 that is branched from the passage 15 and communicates with the pressure chamber 8, and the pressure adjustment means 20 is composed of a groove 18 formed along the circumferential direction of the poppet valve 3. , and a discharge passage 19 that is connected to the fluid passage 15 through the groove 18 and supplies working fluid to the turbine 21 and the like.

That is, the groove 18 formed in the poppet valve 3
The shaft portion 4a of the valve stem 4 is configured to function as a pressure regulating valve for the supplied working fluid. Specifically, the poppet valve 3 is configured to function as a pressure regulating valve for the supplied working fluid.
When the valve is in the open state, the groove portion 18 of the valve stem 4 is connected to the fluid passage 15 and the discharge passage 19.
It is formed so as to be located below. When the valve opening device 13 releases the biasing force against the movable cylinder 7, the poppet valve 3 is moved in the valve closing direction by the working fluid pressure supplied from the fluid passage 15 and the fluid introduction passage 16 to the pressure chamber 8. When the groove portion 18, the fluid passage 15, and the discharge passage 19 are connected together, the working fluid is branched to the pressure chamber 8, the turbine 21, etc., and the poppet valve 3 is activated. The urging force in the valve closing direction is reduced, and the poppet valve 3 is operated only by inertia force. When the groove further passes through the fluid passage 15 due to its inertial force, the discharge passage 19 is again blocked by the shaft 4a of the valve stem 4, and the working fluid is again supplied only to the pressure chamber 8, and the poppet valve 3 Then, the urging force in the valve closing direction is supplied again. Therefore, the poppet valve 3
loses acceleration in the valve closing direction due to the groove 18 and sits on the valve seat 9 without shock only by inertia force,
The valve seat 9 is configured to be tightly engaged with the valve seat 9.

The effects of the embodiment will be explained below.

A guide tube 7 is provided on the cylinder head 1, and a fluid cylinder fitted movably along the guide tube is provided to form a pressure chamber 8, and one end of the valve stem 4 of the poppet valve 3 is attached to the movable cylinder 7. 6 are connected to each other, and the shaft portion 4a is slidably installed inside the guide tube 7, so that when the working fluid is supplied from the fluid supply means 17 to the pressure chamber 8, the movable cylinder 7 and poppet valve 3 are valve seat 9
A biasing force is applied to the valve in the valve closing direction, and the valve seat 9 is tightly engaged with the valve seat 9.

When the bottom part 10 of the moving cylinder 7 is pressed by the piston 11 of the valve opening device 13 in order to move the poppet valve 3 in the valve opening direction relative to the valve seat 9, the moving cylinder 7 and the poppet valve 3 are moved. It moves away from the seat 9 and opens the intake and exhaust passage 2.

Next, the fluid supply means 17 and pressure adjustment means 20 for seating the poppet valve 3 on the valve seat 9 while cushioning it will be explained.

The groove 18 of the poppet valve 3, which is slidably provided in the guide hole 14 of the guide cylinder 5, is provided as a pressure regulating valve, and is used as a pressure chamber such as the fluid passage 15, fluid introduction passage 16, etc. that constitute the fluid supply device 17. A supply system that supplies working fluid to the turbine 8 and a discharge system that supplies the turbine 21 and the like through the fluid passage 15 and the discharge passage 19 by the groove 18.

That is, when the poppet 3 is in the open state by the valve opening device 13, and the groove portion 18 is located below the fluid passage 15 and the discharge passage,
The flow of the working fluid to the discharge system is cut off by the shaft portion 4a of the valve stem 4, and the working fluid is supplied only to the supply system to the pressure chamber 8, and the poppet valve 3 is biased in the closing direction. become.

Here, when the urging force of the valve opening device 13 is released, the poppet valve 3 is moved in the valve closing direction by the urging force of the fluid supply means 17, but the groove portion 18
moves to a position where it communicates with the fluid passage 15 and the discharge passage 19, the working fluid in the fluid passage 15 is supplied to the discharge passage 19 via the groove 18, and the pressure chamber 8
The fluid supply pressure to the poppet valve 3 is significantly reduced, and the urging force to the poppet valve 3 in the closing direction is substantially lost. However, the poppet valve 3 still has inertia, which causes it to gradually sit on the valve seat 9.
Further, when the groove portion 18 moves through the passages 15 and 19, fluid is again supplied to the pressure chamber 8, so that the biasing force within the pressure chamber 8 is restored and the poppet valve 3 is tightly engaged with the valve seat 9. It is possible. Note that when the groove portion 18 moves relative to the passages 15 and 19, the discharge passage 19 is gradually closed and the supply pressure to the pressure chamber 8 increases.
Regarding this, if the position of the groove 18 is optimally set with respect to the opening/closing stroke of the poppet valve 3, the opening/closing speed of the poppet valve 3 can be set arbitrarily, and accordingly the poppet valve 3 and the valve seat 9 and each sliding surface can be formed and coated with ceramic to improve wear resistance, heat resistance, and corrosion resistance, and the poppet valve 3 can be formed into a shape with good cooling performance.

Further, although the pressure adjusting means 20 has been described using the groove portion 18 and the discharge passage 19, the present invention can also be achieved even if the groove portion 18 is a hole.

Next, other embodiments of the present invention will be specifically described.
Since the configuration is the same except for some other parts, the explanation about them will be omitted.

As shown in FIG. 2, the poppet valve 3, which is biased in the valve opening direction by the valve opening device 13, is formed by the movable cylinder 7 and the guide tube 5 when the biasing force of the valve opening device 13 is released. A working fluid is supplied to the pressure chamber 8 by a fluid supply means 17. Specifically, the fluid supply means is provided in the guide cylinder 8, intersects with the guide hole 14 of the poppet valve 3, passes through it, and is connected to the fluid introduction passage 16 to communicate with the pressure chamber 8, Further, the pressure regulating means 20 is arranged in first and second groove portions 18 and 18a provided at intervals along the circumferential direction of the valve stem 4 of the poppet valve, and in the first and second groove portions 18 and 18a. The first groove portion 18 and the shaft portion 4a have a diameter approximately equal to that of the fluid passage 15, and the second groove portion 18a has a diameter smaller than the total lift of the poppet valve 3. It is formed slightly smaller.

That is, when the poppet valve 3 is opened by the valve opening device 13, the fluid passage 15 and the fluid introduction passage 16 are in communication with each other through the second groove 18a, so that the working fluid is It is supplied to the pressure chamber 8 and is configured to apply an urging force to the poppet valve 3 in the valve closing direction. Further, when the urging force of the valve opening device 13 is released from this state, the poppet valve 3 is moved in the valve closing direction together with the moving cylinder 7 by the fluid pressure of the pressure chamber 8, but the poppet valve 3 is moved to the position of the fluid passage 15 as described above. When the shaft portion 4a of the valve stem 4 is moved, the passage 15 is temporarily closed, and the supply of working fluid to the pressure chamber 8 is stopped or reduced by the section of the shaft portion 4a. However, the poppet valve 3 still has an inertial force in that state, and continues to move in the valve closing direction and attempts to sit on the valve seat 9. In this state, the fluid passage 15 and the second groove 1 of the valve stem 4 are connected to each other just before the valve seat 9 is seated without impact.
8a, the fluid pressure to the pressure chamber 8 is restored again, but since the poppet valve 3 has no acceleration or acceleration stroke accompanied by an impact force, the poppet valve 3
is configured to be further tightly engaged with the valve seat 9 after seating on the valve seat 9 without impact force.

An auxiliary passage 15a is provided in the discharge passage 19 in FIG. 1 and in the pressure chamber 8 branched from the fluid passage 15 of the guide tube 5 in FIG. On-off valve 22,
23 etc. are provided, and when they are opened, the poppet valve 3 is moved in the closing direction by fluid pressure to absorb the slack between the poppet valve and the piston 11 of the valve opening device 13. Further, in FIG. 2, a buffer member 24 such as a torsion coil spring is provided between the piston 11 and the movable cylinder 7 to eliminate play between the piston 11 and the movable cylinder 7.

[Effects of the Invention] According to the present invention, the following excellent effects are achieved.

(1) A groove is provided on the valve stem of the poppet valve, and the structure is such that the groove and the stem of the valve stem function as an on-off valve for the fluid passage, and the poppet valve is seated in a cushioned manner on the valve seat, so the structure is simple. can reduce costs.

(2) Since a compressible fluid such as air is used as the working fluid, the poppet valve is not rapidly accelerated and no impact force is generated, and the poppet valve and valve seat are closely engaged to prevent leakage of gas, etc. can.

(3) Since the impact force can be reduced, poppet valves and valve seats can be designed to be lighter and have a cooling structure.For example, it is possible to use ceramic molding or ceramic coating, which has excellent wear resistance, heat resistance, and corrosion resistance. can.

(4) Noise is reduced because the impact force can be reduced.

(5) In order to supply the fluid supplied to the pressure chamber to the accumulator or turbine, the working fluid that controls the speed of the poppet valve can be used efficiently without waste.

(6) Since the pressure inside the pressure chamber can be detected by providing an on-off valve in the passage communicating with the pressure chamber, the poppet valve is not kept open.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a poppet valve device showing a preferred embodiment of the present invention, and FIG. 2 is a schematic sectional view showing another embodiment. In the figure, 3 is a poppet valve, 4 is a valve stem, 5 is a guide cylinder, 7 is a moving cylinder, 8 is a pressure chamber, 9 is a valve seat,
17 is a fluid supply means, and 20 is a pressure adjustment means.

Claims (1)

[Claims] 1. A poppet valve seated on a valve seat and provided to open and close the poppet valve, a guide tube that slidably guides a valve stem of the poppet valve to the valve seat, and a poppet valve provided so as to be movable along the guide tube. a movable cylinder which forms a pressure chamber with the guide cylinder and is connected to the valve stem, and a poppet valve which is connected to the movable cylinder and is connected to the movable cylinder in order to move the poppet valve in the valve opening direction. a valve opening device; a fluid supply means provided to supply working fluid into the pressure chamber to move the valve in the valve closing direction; and a fluid supply means for adjusting the fluid pressure from the fluid supply means to the pressure chamber; A poppet valve driving device comprising: pressure adjusting means provided so as to be cushioned and seated on the valve seat.