JPS5815706A - Exhaust valve device - Google Patents

Abstract

PURPOSE:To prevent working gas from leaking during the closure of the exhaust valve of an exhaust valve device and facilitate checking and maintenance, by using the pressure of the working gas and the force of a spring to keep the exhaust valve closed and by integrating all the parts of the device except its exchaust port, at the side of a piston. CONSTITUTION:When an intake valve 28 is open, high-pressure working gas is introduced into an expanding chamber 17 through a gap 19 and an intake/ exhaust hole 25. In the process of expansion, the closure of an exhasut valve 2b is maintained by the pressure of the working gas and the force of a backup spring 18 until just before the end of the process. When a piston 15 has started going up toward the top dead center, the exhaust valve 2b is pushed on the inside surface of a cylinder 14 by the force of the backup spring 18 so that the exhaust valve is kept open. According to this constitution, the prevention of leakage of the gas and checking and maintenance are facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust valve device for a reciprocating low-temperature expansion engine that has a reciprocating mechanism such as a piston and generates extremely low temperatures.
In particular, it relates to an exhaust valve device suitable for automatically opening and closing an exhaust valve at a predetermined position by utilizing the reciprocating motion of a piston.

Conventionally, in the exhaust valve device of a reciprocating type low-temperature expansion engine, the exhaust valve in the low-temperature section is directly connected to the relief mechanism consisting of the crankshaft, cam, valve pull rod device, etc. in the room-temperature section. It is necessary to prevent the leakage of working gas such as helium gas (hereinafter referred to as "working gas") and to prevent the intrusion of heat from the normal temperature part to the low temperature part, which has the disadvantage of complicating the structure. Therefore, recently, the installation of the valve mechanism consisting of the crankshaft, cam, valve pull rod device, etc. in a room temperature area has been eliminated, and an exhaust valve system that uses the reciprocating motion of the piston to open and close the exhaust valve has been introduced. has been devised.

An example of a conventionally known exhaust valve device that uses reciprocating motion of a piston to open and close an exhaust valve will be described with reference to FIG.

゛Figure 1 is a sectional view of the exhaust valve device described in Japanese Utility Model Publication No. 52-1683+ (L64). A hole 3 with a diameter and length is bored, a valve rod 5 with a spring 4 and 4 is inserted into the hole 3, and a hole 10 is provided through which a stopper 6 is screwed and penetrated in the axial direction.11 14 is a cylinder, and 14 is a cylinder; The valve seat body 7 is airtightly screwed into the piston, and its top surface and the lower end surface of the exhaust valve body are sufficiently thin and flexible, and the piston b is Wire 1 of such length that it can extend straight to 1 and open the exhaust valve body when the exhaust valve body is moved to the opening position of the exhaust valve body facing 2α toward the point side.
They are connected by 6. Note that 17 is an expansion chamber.

2. In the exhaust valve device having such a structure, while the exhaust valve is seated on the valve seat 8 and in the closed state, the pressure of the working gas inhaled through the intake valve (not shown) is used to increase the pressure inside the expansion chamber 17. Since the pressure inside the exhaust hole is always higher than the pressure inside the exhaust hole, an upward force is applied to the exhaust valve. In this case, the spring force of the spring lever is set to be smaller than the force when pushing up, and no force is applied to the exhaust valve body during other depressions. Hold. Due to the expansion of the working gas sucked into the expansion chamber 17, the piston stop Q moves downward toward the bottom dead center, and when it reaches the opening position of the exhaust valve command, the wire 16 is fully extended straight and the The push-down force caused by the lowering of the piston 1 is released to the push-up force 2 that had been applied to the exhaust valve element 11 and the exhaust valve element 1 until then, and the exhaust valve t is immediately moved by the spring force of the spring ν. It will be fully opened. This state continues until the piston passes through the bottom dead center, rises again towards the top dead center, and the top surface of the piston comes into contact with the tip surface of the flanged valve rod 5. During this period, the inside of the expansion chamber 17 Working gas is exhausted from the exhaust hole. After contacting the tip of the flanged valve stem 5, it further rises to the piston and pushes up the flanged valve stem 5, but
In this case, since the spring force of the spring 4 and the force applied to the spring 1 of the spring set are set to be large, the flanged valve stem 5 rises together with the exhaust valve body Φ2, and the exhaust valve is 2Q.

It seats on the valve seat 8 and closes the valve. The spring 4 becomes a cylinder until the exhaust valve closes and the piston reaches top dead center. After that, the piston moves downward toward the bottom dead center again, but at this point, the working gas starts to be sucked into the expansion chamber 17.
Even if the top surface of the piston is separated from the tip surface of the flanged valve stem,
Due to the pressure of the working gas sucked into the expansion chamber 17, the exhaust valve is kept closed. Thereafter, the above operation is repeated.

q In such an exhaust valve device, the top surface of the piston and the lower end surface of the exhaust valve body are connected by a wire 16, and the reciprocating motion of the piston diameter is used to open and close the exhaust valve Φ. , it has the advantage of eliminating the need to install the valve mechanism consisting of a cam, a valve pull rod device, etc. in a room temperature section, but on the other hand, when the operating bus expands, the 2nd east exhaust valve φ is closed. Because the exhaust valve φ is pressed against the valve seat 8 with insufficient force, leakage of the working gas is likely to occur. Another drawback was that it was not easy to assemble as it needed to be connected to the top surface of the exhaust valve, and furthermore, most of the components of the exhaust valve device were concentrated on the cylinder side, making maintenance and inspection difficult. .

The present invention is aimed at eliminating the above-mentioned drawbacks, and is provided with an exhaust hole penetrating through the side wall of the upper end of the cylinder, at a position corresponding to the exhaust hole, and so as to slide on the inner surface of the cylinder. A ring-shaped exhaust valve is installed.The rS mosquito exhaust valve is automatically opened and closed at a predetermined position using the reciprocating motion of the piston via a valve pull rod provided on the exhaust valve body, and furthermore, the exhaust hole is removed. To provide an exhaust valve device in which all the constituent parts of the exhaust valve device are concentrated on the piston side, and assembly and maintenance and inspection of the exhaust valve device can be easily performed by taking the piston and the device out of the cylinder.

An embodiment of the present invention will be explained with reference to FIGS. 2 to 5.

Note that in FIGS. 2 to 5, parts and the like that are the same as those in FIG. 1 are designated by the same reference numerals, and explanations thereof will be omitted. First, in Figures 2 and 3,
Reference numeral 9b indicates an exhaust hole provided through the upper end side wall of the cylinder 14, and reference numeral 2b indicates a ring-shaped exhaust valve provided at a position corresponding to the exhaust hole 9b so as to slide on the inner surface of the cylinder 14. A ring is attached to the valve body tb via a backup spring tin.

Retained. In this case, the exhaust valve 2b is installed so that a predetermined gap W is created between the upper end surface of the exhaust valve body 1b and the inner surface of the head of the cylinder 14 when the exhaust valve 2b is closed, and the other end of a is connected to the lower end of the exhaust valve body ib. It is fixedly installed around the axis of the valve body 1b or is formed integrally with the exhaust valve body 1b.

4 is a guide hole which has a diameter larger than the outer diameter of the valve pull rod 20g and is drilled from the top side of the piston shaft centering on the axis of the exhaust valve body 1b and the piston body. ) Temporarily store a and move it back and forth smoothly. 23m
has a tail 24m at one end with a diameter that is approximately the same as the inner diameter of the valve pull rod 2Da, and the diameter of the part excluding the boxwood 24m is that of the valve pull rod 2.
The guide rod has approximately the same diameter as the inner diameter of the 0m retaining member 211, and one end of the guide rod 23m protrudes beyond the guide hole n, and the other end is centered on the axis of the guide hole 4 at the bottom of the guide hole 4. It is planted as a. Reference numeral 3 denotes a working gas intake/exhaust hole, which is provided at least one through the exhaust valve body 2b. Song is expansion @ 1
7. The inner space of the valve pull rod 20a communicates with the gap 4, and the exhaust valve body 2b is provided with at least one exhaust groove 4 on the circumference. The exhaust hole provided therein is an intake valve provided in the head of the cylinder 14.

Figure 2 shows the state when the piston b is located at the top dead center. In this state, the intake valve is open and high pressure working gas flows into the gap 19. Although it is sucked into the expansion 1117 through the rl & exhaust hole 5, the working gas pressure inside the expansion 117 is maintained at a constant pressure because the exhaust valve 2b is closed. When the piston begins to move downward toward the bottom dead center from the state shown in Fig. 2, the intake valve 2b closes, the intake stroke ends, and then the expansion stroke begins, but during this time, the exhaust valve 2b is closed. The valve state is maintained until just before the end of the expansion stroke due to the operating gas pressure and the spring force of the backup spring. If the piston moves further down, the 23m guide rod Tamimaro Tsuba becomes the holding member for the 20m valve pull rod. Z1m, the exhaust valve body 1b is pulled down, the exhaust valve 2b slides and becomes open], and expands m1.
7 and the exhaust hole 9b communicate with each other, and exhaust begins. After that, the piston tube further descends and reaches the bottom dead center shown in Fig. 3, and then reversely starts to rise toward the top dead center, but during this time, the exhaust valve 2b is moved by the spring force of the backup spring. cylinder 1
The valve is held open by being pressed against the inner surface of 4, and the expansion valve 1
The working gas in 7 has an intake/exhaust hole and a valve puller 11112D.
Inner space a, exhaust hole 9b via exhaust hole and gap 4
[Yo] is exhausted. When the piston b approaches the top dead center, the guide hole 4
The lower end surface of the retaining member 4 of the valve pull rod 2Dm comes into contact with the bottom surface of the valve pull rod 2Dm, or the top surface of the piston center comes into contact with the lower end surface of the exhaust valve body 1b. The exhaust hole 9b is closed by the exhaust valve 2b, and the valve is closed. Thereafter, the piston moves upward and returns to top dead center as shown in FIG. Similarly, intake,
In this case, the opening/closing timing of the exhaust valve 2b is determined by the guide rod 23 when the piston stop is at the top dead center (the state shown in FIG. 2).
Engagement member Z1m between the lower end surface of the collar 24m and the valve pull rod 201
The relationship between the distance from the upper end surface, the length of the valve pull rod 2Dm, and the depth of the guide hole ρ, or the relationship between the top surface of the piston intestine and the exhaust valve body when the piston b is at the bottom dead center (the state shown in Figure 3) By appropriately selecting the distance from the lower end surface of lb,
And it can be set automatically.

Figures 4 and 5 show that the valve pull rod is fixed to the outer part of the exhaust valve body so as to reciprocate along the inner surface of the cylinder, and that a groove for the reciprocating movement of the valve pull rod is provided on the outer surface of the piston. In this example, Fig. 4 shows the state when the piston is located at the top dead center, and Fig. 5 shows the state when the piston is located at the bottom dead center. . Figure 4, Figure 5, Figure 2, summary 3
Components that are the same as those in the drawings are designated by the same reference numerals and their explanations will be omitted. Lc is the exhaust valve 2b through the backup spring.

has been done. 2ob is a valve pull rod with a retaining member 21b provided at one end, and the other end is fixed to the lower end of the exhaust valve body 1c, and at least two pieces are fixed on the circumference or the exhaust valve body 1
It is formed integrally with c. 4 is a guide groove for temporarily storing the valve pull rod 20b and making it reciprocate smoothly, and there are 9 pieces in the shape of the valve pull rod 2ob on the outer peripheral surface of the piston b and from the top surface side of the piston gut. It is set up correspondingly. 24b is a collar provided at the upper end of the guide groove 4, and its outer diameter is equal to that of the retaining member nb of the exhaust valve body IC and the valve pull rod 20b.
It is larger than the inner diameter of the valve pull rod 20b and smaller than the inner diameter of the valve pull rod 20b. In addition, the exhaust valve body 1 is removed from the top surface of the piston.
The diameter of the longitudinal portion corresponding to the width c is also smaller than the inner diameter of the exhaust valve body 1c to prevent the piston from contacting the inner surface of the exhaust valve body 1c during reciprocation.

Even in the exhaust valve device having such a structure, the exhaust valve 2b operates in the same way as the nine functions described with reference to FIGS. 2 and 3, and the exhaust valve 2b automatically opens and closes using the reciprocating motion of the piston. That is, when the piston intestine moves downward from the top dead center position in FIG. 4 toward the bottom dead center, the boxwood 24b of the piston intestine
[The lower end surface and the upper end surface of the retaining member 21b of the valve pull rod zb come into contact and the valve pull rod zb is pulled down] The exhaust valve 2b opens and is located at the bottom dead center in FIG. When the piston intestine moves upward toward the top dead center from the current state, the upper end surface of the piston intestine's boxwood 24b and the lower end surface of the valve body 1c come into contact, and the exhaust valve body jc is pushed up, thereby causing the exhaust valve 2b to open. is closed. Also in this case, the opening/closing timing of the exhaust valve 2b,
The distance between the lower surface of the boxwood 24b and the upper end surface of the retaining member 21b when the piston lever is at the upper west point (state shown in FIG. 4);
When the piston 15 is at the bottom dead center (state shown in Fig. 5)
This can be set appropriately by appropriately selecting the distance between the upper end surface of the boxwood 24b and the lower end surface of the exhaust valve IC.

FIG. 6 shows another embodiment of the flange structure of the discrimination rod and guide rod shown in FIGS. 2 and 3, and the discrimination rod 20c includes:
The retaining member 21 shown in FIGS. 2 and 3 with a portion of its lower end remaining
At least two slits are provided in the mid-length direction at appropriate intervals on the circumference (comparable to m). In addition, at the upper end of the guide rod 23b, a collar 24c is provided at a position corresponding to the slit 30 and has a width narrower than the slit width and an outer diameter approximately equal to the outer diameter of the discrimination rod 20c. Also, the diameter of the guide rod 23b excluding the collar 24c is the discrimination rod 20C.
The diameter is almost the same as the inner diameter of the If the structure of the flanges of the discrimination rod and the guide rod is made in this way, the force of the discrimination rod C during reciprocation will be reduced.
Mechanical expansion of the lower end in the radial direction can be prevented.
The opening/closing operation of the exhaust valve 2b can be made smooth and the opening/closing timing can be maintained appropriately. Figures 7 and 8 show other embodiments in which the exhaust valve is mounted and held in the exhaust valve body. As shown, the exhaust valve body tb has a circular spring holder and an exhaust valve 2 at a predetermined depth from its outer peripheral surface.
b is ring-mounted and held. If a spring is used in addition to the backup spring to encircle and hold the exhaust valve around the exhaust valve body in this way, the pressure of the backup spring against the inner surface of the cylinder 14 of the exhaust valve 2b is insufficient. Even if this happens, this shortage is compensated for by the spring force of the spring, so that leakage of working gas when the exhaust valve 2b is closed due to insufficient pressing force can be prevented.

Fig. 9 shows another embodiment in which the exhaust hole is provided in the cylinder side wall, in which the sliding amount of the exhaust valve determined by the stroke of the piston is also small in diameter, and a plurality of exhaust holes 9C are provided. are provided adjacent to or apart from each other on the circumference of the upper end side wall of the cylinder 14 and penetrating therethrough. When the exhaust hole 9C is provided in the upper end side wall of the cylinder 14 in this manner, the shortage of the actual flow path area of the exhaust hole is suppressed, so that the working gas can be exhausted satisfactorily.

FIG. 10 shows another embodiment of the exhaust hole shape, in which the exhaust hole 9d has an elliptical or slender shape with a width narrower than the sliding amount of the exhaust valve determined by the stroke of the piston, and the exhaust hole 9d has a circular shape on the upper end side wall of the cylinder 14. It is provided to penetrate around the circumference. Even when the exhaust hole is shaped in this way, the shortage of the actual flow path area of the exhaust hole is suppressed, so that the working gas can be exhausted satisfactorily.

As explained above, the present invention satisfactorily maintains the closed state of the exhaust valve of an exhaust valve device used in a reciprocating type low-temperature expansion engine using working gas pressure and spring force, and exhausts the exhaust gas excluding the exhaust hole. Since all the components of the valve device are integrated on the piston side, leakage of working gas when the exhaust valve is closed can be prevented, and assembly and maintenance inspection of the exhaust valve device can be easily performed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional exhaust valve device that uses the reciprocating motion of a piston to open and close an exhaust valve, and FIGS. 2 to 5 illustrate an embodiment of the present invention. , second
Figure 3 is a sectional view of an exhaust valve device in which a discrimination rod is provided in the center of the exhaust valve body, and Figures 4 and 5 are exhaust valve devices in which a discrimination rod is provided in the outer periphery of the exhaust valve body. Figure 6 is a cross-sectional view of the device, and Figure 8 is a cross-sectional view showing an embodiment of discrimination.
9 is a partial internal plan view showing another embodiment in which the exhaust hole is provided in the upper end side wall of the cylinder, and FIG.
FIG. 7 is a partial internal plan view showing another example of the shape of the exhaust hole. lb, lc...exhaust valve body, 2b...exhaust valve, 9b, 9c, 9d...exhaust hole, 14...
...Cylinder, 15...Piston, 17.
...Expansion chamber, audience...No (tuck-up spring, 19...gap, 20m, 2) b, 20c.
... Discrimination rod, 211.21b ... Retaining member, η ... Guide hole, 23a, 23b ...
Guide rod, 24 m, 24 b, 24 c-=brim, δ...Intake and exhaust hole, Uta...Exhaust hole, γ...Exhaust groove, grave ...Intake valve,
4... Guide groove, garden... slit, aim.
...Spring storage hole, depth...Spring'1'1
Figure 'F;8;! J ↓ Age 3 figure Age 4 figure 7 Age 5 figure O 6 figure off u Age 8u ″Jr9 figure

Claims (1)

[Claims] 1. In an exhaust valve device used in a reciprocating low-temperature expansion engine composed of a piston, a cylinder, etc., and composed of an exhaust valve, an exhaust hole, etc., an exhaust valve device that penetrates the upper end side wall of the cylinder. the exhaust hole provided in the mosquito exhaust hole; the ring-shaped exhaust valve installed inside the cylinder at a position corresponding to the mosquito exhaust hole and sliding on the inner surface of the cylinder side wall; and the exhaust valve mounted on the outer peripheral surface; An exhaust valve device comprising: an exhaust valve body to be held; a collar formed integrally with the piston; and a valve pull rod integrally formed with the exhaust valve body and engaged with the boxwood. 2. The exhaust hole has a diameter smaller than the sliding amount of the ring-shaped exhaust valve determined by the stroke of the piston, and a plurality of the exhaust holes are provided adjacent to or apart from each other on the circumference of the upper end side wall of the cylinder. An exhaust valve device according to claim 1. 3. The exhaust valve device according to claim 1, wherein the shape of the exhaust hole is an ellipse or an elongate shape with a narrower width than the sliding amount of the ring-shaped exhaust valve determined by the stroke of the piston. . 4. The exhaust valve device according to claim 1, wherein a retaining member that engages with the ridge is formed at one end of the valve pull rod. 5. The exhaust valve device according to claim 1, wherein the ring-shaped exhaust valve is surrounded and held on the outer peripheral surface of the exhaust valve body via a backup spring. 6. The exhaust valve device according to claim 5, wherein the backup spring has a compressed spring provided therein. Range 1, 5 or 8, the valve pull rod is formed integrally with the disk-shaped exhaust valve body at an angle of Δ with the axis of the disk-shaped exhaust valve body, and the valve pull rod is housed. A guide hole to be obtained is bored from the top surface side of the piston, and the diameter is at least approximately the same as the inner diameter of the engaging member of the valve pull rod,
and a patent claim in which the guide rod has one end protruding from the guide hole and the other end is embedded in the bottom of the guide hole centered on the axis of the guide hole, and the above-mentioned guide rod is movably installed in the valve pull rod. Range 1! #
! The exhaust valve device according to item 7. 9. The disc-shaped exhaust valve body is installed so that a predetermined gap is created between the upper end surface of the disc-shaped exhaust valve body and the inner surface of the head of the cylinder when the piston is located at the top dead center. Claim 8: The exhaust valve device according to claim 8, wherein the exhaust valve device is provided so as to pass through at least the first part of the lower part. 11. An exhaust hole having at least one exhaust groove provided on the circumference, centered on the axis of the disc-shaped exhaust valve body;
9. The exhaust valve device according to claim 8, wherein the brim is provided so as to penetrate through a disc-shaped exhaust valve body so as to be able to accommodate the brim. 12. Providing at least two slits in the longitudinal direction at appropriate intervals on the circumference so as to leave a portion of the lower end portion of the valve pull rod and form the engaging member, and make the shape of the brim into the slit. An exhaust valve device according to claim 8, which has a corresponding shape. 13. At least two of the valve pull rods are formed integrally with the ring-shaped exhaust valve body at an outer part of the ring-shaped exhaust valve body, and a guide groove capable of accommodating the valve pull rods is formed on the outer peripheral surface of the piston. 8. The exhaust valve device according to claim 7, wherein the piston is provided from the top side of the piston, and the rib is formed at the upper end of the guide groove. 14. The exhaust according to claim 13, wherein the diameter of the top surface side of the piston having a length corresponding to the width of the ring-shaped exhaust valve body is also smaller than the inner diameter of the ring-shaped exhaust valve body. Valve device.