JPS6316587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-pressure pump, and particularly to a high-pressure pump that can increase discharge pressure by having a fixed piston and moving a cylinder to perform a pumping action.

Conventionally, in order to pump cryogenic fluid such as liquid hydrogen from its storage tank, a piston rod using a hollow tube with a small cross-sectional area is used in a high-pressure pump designed to prevent heat transfer from the outside world as much as possible. So,
A disadvantage is that the stress required to push the piston down causes the piston rod to buckle. Furthermore,
The suction valve cannot respond to the high-speed reciprocating motion of the piston, resulting in the inconvenience that fluid cannot be fed at a desired high pressure.

Note that the need to pump a cryogenic fluid such as liquid hydrogen arises, for example, when this liquid hydrogen is used as a fuel for an internally twisted engine. And preferably,
It is desirable to feed liquid hydrogen at a high pressure of about 100 kg/ ^cm2 , and high-pressure feeding improves the dispersion of the injected fuel and can greatly improve the combustibility of the engine, so it is desirable to realize this. It was rare.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks, provide a movable cylinder, provide a suction valve that responds to the movement of the cylinder, and provide a system capable of pumping fluid at a high discharge pressure, while also providing a method for delivering cryogenic fluids. The object of the present invention is to realize a high-pressure pump that prevents as much as possible the inflow of heat from the outside world into a storage tank.

In order to achieve this object, the present invention provides a fixed piston at the lower end of the first rod made of a hollow tube, and a discharge valve is provided at the upper end of the press-fit passage provided through the center of the fixed piston. 1st
A second rod, which is made of a hollow tube with a smaller diameter than the first rod and moves back and forth at high speed, is disposed within the rod, concentrically with the first rod and with a gap between both rods, and at the lower end of the second rod. The upper end of a connecting pipe extending from inside the first rod to the outside of the lower end of the first rod is fixedly provided, and a movable cylinder that engages with the fixed piston is connected to the lower end of the connecting pipe, and the movable cylinder and the fixed piston are connected to the lower end of the connecting pipe. A pump chamber is formed in the movable cylinder by a piston, and a suction valve is interposed between the pump chamber and a suction port formed at a lower part of the movable cylinder, and the suction valve provided in the movable cylinder is movable. When the cylinder moves downward for suction, the suction valve remains due to inertia and opens at a minute distance from the valve seat of the movable cylinder moving downward, and when the movable cylinder moves upward for pressure feeding, the suction valve opens at a minute distance from the valve seat. The movable cylinder is characterized in that it is configured to move downward due to inertia during downward suction movement and collide with the valve seat of the movable cylinder that moves upward, thereby closing the valve.

Embodiments of the present invention will be described in detail and specifically below based on the drawings. 1 and 2 show an embodiment of the invention. The high pressure pump 2 is generally composed of a piston section 4, a cylinder section 6, and a crank section 8 that reciprocates the cylinder section 6.

The piston part 4 has a fixed piston 10,
This fixed piston 10 is formed at the lower end of a first rod 12 made of a large diameter hollow tube. and,
A press-fit passage 14 through which fluid passes passes through the center of the fixed piston 10.

Further, the cylinder portion 6 is configured as follows. As shown in FIG. 1, a second rod 16 made of a hollow tube with a smaller diameter than the first rod 12 is placed within the first rod 12 concentrically with the first rod 12 and with a gap between the two rods. A connecting pipe 18 is fixed to the lower end of the second rod 16. Vertically cut out both sides of this connecting pipe 18,
A vertically elongated hole that bypasses the lower end member of the first rod 12 is formed. As a result, the connecting pipe 18 reaches from inside the first rod to outside the lower end of the first rod, as shown in FIG. And this connecting pipe 1
A movable cylinder 20 is provided connected to the lower end of 8,
This movable cylinder 20 is fitted onto the fixed piston 10.

In the figure, a slider 22 is attached to the upper end of the second rod 16, and a connecting rod 24 of the crank portion 8 is pivotally attached to this slider 22.
is pivotally mounted on the crank 26. That is, this crank portion 8 converts the rotational movement of the crank 26 into direct movement via the connecting rod 24, and further causes the movable cylinder 20 to reciprocate via the second rod 16 and the connecting pipe 18.

This movable cylinder 20 and the fixed piston 10
A pump chamber 28 is formed within the movable cylinder 20, and a suction port 30 is provided at the bottom of the movable cylinder 20.
form. In addition, the pump chamber 28 and the suction port 30
A suction valve 32 is interposed between the two. As shown in the first figure, when the movable cylinder 20 moves downward as a suction operation, the suction valve 32 remains in that position due to inertia, and a small amount is removed from the valve seat 34 of the movable cylinder 20 moving downward. spaced apart by an interval,
The valve is configured to open by opening the suction port 30. Furthermore, when the movable cylinder 20 moves upward as part of the pressure-feeding operation, the suction valve 32, which is spaced apart from the valve seat 34 by a minute distance, moves downward due to inertia during the downward movement, and impinges on the valve seat 34 of the movable cylinder 20 that moves upward. The structure is such that the suction port 30 is closed and opened when the suction port 30 is in contact with the valve.

A discharge valve 36 is interposed at the upper end of the press-fit passage 14 provided in the fixed piston 10 of the first rod 12, and the tip of this discharge valve 36 is inserted into the press-fit passage 14.
The discharge pipe 3 is brought into contact with the upper end opening, and the discharge pipe 3 is connected to the upper end of the press-fit passage 14 via the discharge valve 36.
8 will be provided. That is, this discharge valve 36 is pushed up by the fluid pressure from below the press-in passage 14,
This allows the press-fit passage 14 and the discharge pipe 38 to communicate with each other. Further, a spring 40 is installed above the discharge valve 36 to bias the discharge valve 36 and press-fit passage 14 in the closing direction. An adjustment screw 42 for adjusting the biasing force of the spring 40 is provided on the upper part of the spring 40 and is screwed into the protrusion 44 .

Furthermore, a mounting flange 48 for mounting the pump body to the tank outer wall 46 is fixed to the upper end of the first rod 12.
A guide frame 50 for supporting the slider 22 is fixedly installed on the upper part of the slider 8. In addition, reference numeral 52 indicates a mounting bolt hole;
4 is a storage tank.

Since the present invention is constructed as described above, it operates as follows.

When the crank 26 rotates and the linking rod 24 is pushed down, the slider 22 moves downward within the guide frame 50, and the second rod 16 and the movable cylinder 20 move downward together with the slider 22. Since this downward movement of the movable cylinder 20 is very fast, the suction valve 32 remains at approximately the original position due to inertia. That is, due to the sudden downward movement of the movable cylinder 20, the suction valve 32 stays in its original position due to the influence of the pressure difference between the outside and the pump chamber 28 as well as the inertia force, and as a result, the suction valve 32 becomes the valve of the movable cylinder 20 that moves downward. It is spaced apart from the seat 34 by a minute distance, and the suction port 30 is opened to open the valve. Then, due to the downward movement of the movable cylinder 20 with the suction port 30 opened, the pressure inside the storage tank 54 becomes relatively higher than that inside the pump chamber 28, and fluid such as liquid hydrogen flows from the storage tank 54 to the suction port 30.
and is sucked into the pump chamber 28.

Furthermore, when the crank 26 rotates and the connecting rod 24 is pulled up, the slider 22 moves upward within the guide frame 50. At this time, the second rod 16 receives a tensile force rather than a compressive force unlike the conventional one, and the second rod 16 and the movable cylinder 20 are moved upward together with the slider 22. The upward movement of the movable cylinder 20 is very fast, and as mentioned above, the suction valve 32, which is spaced apart from the valve seat 34 by a minute distance, moves downward due to the inertia force during the downward movement, and the movable cylinder 20 moves upward. The suction port 30 is operated to block the suction port 30 by colliding with the valve seat 34 of the valve seat 34 .
This prevents backflow of liquid hydrogen from the suction port 30. Further, due to the upward movement of the movable cylinder 20, pressure is applied to the liquid sucked into the pump chamber 30. However, since the upper end of the press-fit passage 14 is kept in a normally closed state by the discharge valve 36, the fluid pressure within this press-fit passage 14 is increased. When the fluid pressure exceeds a predetermined pressure, the discharge valve 36 is pushed upward in the figure, and the discharge valve 36 is opened by overcoming the biasing force of the spring 40 biasing the discharge valve 36. As a result, the press-in passage 14 and the discharge pipe 38 are communicated with each other, and high-pressure fluid is discharged from the discharge pipe 38.

The reciprocating motion of the movable cylinder 20 is about 1000 to 1500 times per minute, thereby making it possible to achieve a discharge pressure of about 60 to 100 kg/cm ² . Despite such high-speed reciprocating motion of the pump, the pump function does not deteriorate due to the suction valve 32.
The law of inertia is used to open the suction valve 32 when the movable cylinder 20 moves downward for suction, and the law of inertia is used to close the suction valve 32 when the movable cylinder 20 moves up for pumping. The point lies in the clever use of In addition, a second rod 16 made of a hollow tube with a smaller diameter than the first rod 12 is placed inside the first rod 12 made of a hollow tube of a larger diameter so as to be coaxial with the first rod 12 and with a gap between both rods. In addition, the second rod, which occupies a large part of the heat inflow path from the outside world, is made thin, that is, has a small cross-sectional area, by having a configuration that receives only tension rather than compression. This effectively prevents heat from flowing into the storage tank 54 from the outside by conduction.

As is clear from the above description, the present invention provides the following effects.

(1) The piston is fixed and a movable cylinder equipped with a suction valve is moved, and a suction valve is installed at the bottom of the movable cylinder that utilizes the law of inertia and can respond to the high-speed reciprocating motion of this movable cylinder. This suction valve reliably performs the valve function, improves pump efficiency, and is capable of pumping fluid at a high discharge pressure of, for example, 60 to 100 kg/cm ² despite its simple configuration.

(2) A second rod made of a hollow tube of a smaller diameter than the first rod is arranged concentrically within the first rod made of a hollow tube of a larger diameter, with a gap formed between the two rods. Since the piston shaft and the cylinder shaft are respectively formed as the piston shaft and the cylinder shaft, it is possible to prevent the conduction and flow of heat from the outside into the storage tank.

(3) In addition, since the second rod is configured to receive only tensile force rather than compressive force as in the past, there is no risk of bending, and the second rod can be made thin, with a small cross-sectional area. , thereby,
Heat entering the storage tank from the outside world can be effectively blocked.

[Brief explanation of the drawing]

1 and 2 show embodiments of the present invention, FIG. 1 being a sectional view of a high pressure pump, and FIG. 2 being a partially enlarged sectional view of FIG. 1. In the figure, 2 is a high pressure pump, 4 is a piston part, 6 is a cylinder part, 8 is a crank part, 10 is a fixed piston, 12 is a first rod, 14 is a press-fit passage, 16 is a second rod, and 20 is a movable part. cylinder, 2
2 is a slide, 24 is a connecting rod, 26 is a crank, 28 is a pump chamber, 30 is a suction port, 32 is a suction valve, 34 is a valve seat, 36 is a discharge valve, 38 is a discharge pipe, 48 is a mounting flange, 54 is a storage tank.

Claims (1)

[Claims] 1. A fixed piston is provided at the lower end of the first rod made of a hollow tube, and a discharge valve is provided at the upper end of the press-fit passage provided through the center of the fixed piston, and a discharge valve is provided from the first rod into the first rod. A second rod made of a hollow tube with a small diameter and capable of reciprocating at high speed is arranged concentrically with the first rod with a gap between the two rods, and a second rod is provided at the lower end of the second rod from inside the first rod. 1. The upper end of a connecting pipe reaching outside the lower end of the rod is fixedly installed, and a movable cylinder is connected to the lower end of the connecting pipe to fit into the fixed piston, and the movable cylinder and the fixed piston are used to connect the movable cylinder to the lower end of the connecting pipe. A pump chamber is formed, and a suction valve is interposed between the pump chamber and a suction port formed at the lower part of the movable cylinder, and the suction valve provided in the movable cylinder is operated by inertia when the movable cylinder moves downward for suction. The remaining movable cylinder opens with a minute gap from the valve seat of the movable cylinder that moves downward, and when the movable cylinder moves upward for pressure feeding, the suction valve that is spaced a minute gap from the valve seat opens due to inertia during the downward suction movement. A high-pressure pump characterized in that it is configured to move downward and close the valve by colliding with a valve seat of the movable cylinder that moves upward.