JPH0250383B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a reciprocating engine in which an intake valve and an exhaust valve are automatically opened and closed in conjunction with a piston.

First, Figure 1 shows the conventional Collins type reciprocating processor.
The configuration of the engine will be explained. An intake port 1 is provided on the bottom plate 103 of the cylinder 102 that houses the piston 101.
04 and an exhaust port 105 are formed, and the cylinder 10
The cylinder 10 is connected to the outside of the cylinder 10 through the intake port 104.
An intake chamber 106 that communicates with the cylinder 2 and an exhaust chamber 107 that communicates with the cylinder 102 through an exhaust port 105 are provided. An intake pipe 108 is installed on the peripheral wall of the intake chamber 106, and an exhaust pipe 1 is installed on the peripheral wall of the exhaust chamber 107.
09 are connected to each other, and each room 106,1
Intake valves 110 and 111 are housed inside the valves 07, respectively. Valve rods 110a, 111a are connected to each valve 110, 111, and a piston rod 101a is connected to the piston 101, respectively.
111a and 101a are arranged parallel to each other in the same direction. Each of the valves 110 and 111 corresponds to each chamber 10.
Spring 112,1 provided in 6,107
13, it is always biased in the closing direction. Each valve rod 110a, 111a is driven by a crankshaft (not shown) and moves forward and backward in opposite directions to alternately open and control the intake port 104 and the exhaust port 105.

In the reciprocating engine shown in FIG. 1, just before the piston 101 reaches top dead center, the intake valve 110
is opened, and after a certain amount of high-pressure gas supplied from the intake pipe 108 flows into the cylinder 102 through the intake port 104, it is closed. At this time cylinder 10
The exhaust valve 111 opens just before the piston 101 reaches the bottom dead center due to the adiabatic expansion of the high-pressure gas in the cylinder 102, and the gas in the cylinder 102 is exhausted to the outside from the exhaust pipe 109 through the exhaust port 105 and the exhaust chamber 107 as low-pressure gas. be done. The valve rods 110a, 111a are driven by a crankshaft (not shown).

However, this type of reciprocating engine had the following drawbacks. Since the pressure inside the cylinder 102 is high, it is necessary to keep the springs 112 and 113 strong in order to reliably close the intake port 104 and the exhaust port 105.
12, 113 are strong, a large amount of power is required to open and close the valves 110, 111, and the valve rods 110a, 113 are strong.
111a had to be made thicker, and had the drawback of low mechanical and thermal efficiency. In addition, since the end of the valve rod is connected to the crankshaft and the valves 110 and 111 are reciprocated by the rotation of the crankshaft, vibration and noise are generated due to the lateral movement of the valve rod, and the durability is also low. Ta. Furthermore, an intake valve 110 and an exhaust valve 11
Valve rods 110a, 11 to drive 1
1a and a rod cam (not shown) for connecting these valve rods and the crankshaft.
Since many parts are required, the structure is complicated, reliability is reduced, weight is increased, and the size is large.

Therefore, the present inventors proposed a reciprocating engine that can automatically open and close intake valves and exhaust valves in conjunction with pistons, as described in Japanese Patent Application No. 54-28203. Figures 2 and 3 are partially cutaway side views of the reciprocating engine. Figure 2 shows the state in which the piston 1 has moved to the bottom dead center, and Figure 3 shows the state in which the piston 1 has moved to the top dead center. It shows the state where it has moved. The piston 1 is housed in the cylinder 2 with the stepped portion 1a as a boundary, the portion below the stepped portion 1a having a small diameter, and the axis thereof oriented in the vertical direction. The cylinder 2 consists of a cylindrical portion 2a and a bottom plate portion 2b, and an intake port 3 is formed in the center of the bottom plate portion 2b, and an exhaust port 4 is formed in the bottom peripheral wall of the bottom plate portion 2b. Note that a cylindrical space 5 is provided inside the peripheral wall of the bottom plate 2b, and this cylindrical space 5
and the internal space of the cylinder 2 are communicated through the exhaust port 4. An exhaust pipe 6 communicating with the cylindrical space 5 is connected to the outer periphery of the bottom plate portion 2b. Further, an intake valve 7 is incorporated in the center of the bottom plate portion 2b. The intake valve 7 includes an outer cylindrical part 8 connected to the center of the lower surface of the bottom plate part 2b and having a small diameter at the lower end. Forced valve body 1
0, and a contacting body 12 which is housed in the valve body 10 so as to be able to rise and fall and is urged upward by a compression spring 11 stronger than the spring 9. Normally, the valve body 10 is closed to the intake air by the spring 9. Mouth 3
It comes into contact with the valve seat 13 on the periphery and closes the intake port 3. The valve body 10 has an inner cylindrical part 14 at its lower part that enters the small diameter part of the outer cylindrical part 8, and a passageway 15 communicating with the large diameter part of the outer periphery 8 is formed on the peripheral wall of the inner cylindrical part 14. is provided. Further, the upper end of the abutting body 12 protrudes into the cylinder 2, and in the second state where the piston 1 is located at the bottom dead center, the abutting body 12 is pushed down by the piston 1 and further resists the elasticity of the spring 11. Then, the valve body 10 is pushed down and separated from the valve seat 13, and the inner cylinder part 14→vent passage 15→
A high pressure gas flow path for the intake port 3 is formed.

A C-shaped spring ring 16 serving as an exhaust valve is housed inside the cylinder 2 . As shown in FIG. 4, this spring ring 16 has a pair of locking pieces 17, 7 extending upward from mutually symmetrical parts on the upper surface, and a tip of the inner surface of each locking piece 17, 17. are provided with locking claws 17a, 17a. The slit portion of the spring ring 16 is connected to a guide pin 2 attached to the inside of the cylindrical portion 2a of the cylinder 2.
1, thereby preventing the spring ring 16 from rotating. A pair of recesses 18, 18 are provided on the outer peripheral surface of the spring ring 16 at mutually symmetrical locations, and curved plates 19, 19 are engaged with each recess 18, 18. The curved plates 19, 19 are pressed against the inner surface of the cylinder 2 by the elastic force of the spring ring 16, and the discharge port 4 is closed as shown in FIG.

A pair of long grooves 20, 20 which are long in the axial direction are provided at mutually symmetrical parts on the outer periphery of the small diameter part of the front piston 1, and the locking pawl 17 is provided in each long groove 20, 20.
a, 17a are inserted. Therefore, the locking claw 1
7a, 17a can move vertically within the range of the long grooves 20, 20, and the locking claws 17a, 17a
The movement of the spring ring 16 relative to the piston 1 is restricted by the engagement of the long grooves 20 and 20.

Next, the operation of this reciprocating engine will be explained.

FIG. 2 shows a state in which the spring 16 serving as an exhaust valve is at the lowest position, the curved plates 19, 19 close the exhaust ports 4, 4, and the piston 1 is located at the bottom dead center. In this state, the contact body 12 is pushed down by the piston 1, and the intake valve 7 is open.
Therefore, when high-pressure gas flows into the cylinder 2 through the intake valve 7, the piston 1 rises, and along with this, the valve body 10 rises due to the spring 9 and comes into close contact with the valve seat 13, and the elasticity of the spring 9 and the gas The pressure ensures that the intake valve 7 is closed. Also piston 1
When the piston 1 rises, the spring ring 16 initially remains in the position shown in Fig. 2 due to the contact pressure between the curved plate 19 and the inner peripheral surface of the cylinder 2, but just before the piston 1 reaches the top dead center The lower edge of the long groove 20 is the locking claw 17
a, the spring ring 16 rises together with the piston 1, and the exhaust ports 4, 4 open, resulting in the state shown in FIG.

That is, Fig. 3 shows the spring ring 1 as an exhaust valve.
6 is at the highest position, the exhaust ports 4, 4 are open, the intake valve 7 is closed, and the piston 1 is located at the top dead center. In this state, cylinder 2
Since the internal space of the piston 1 is communicated with the outside through the exhaust pipe 6, the piston 1 moves downward. At this time, the spring ring 16 initially remains in the position shown in FIG. 3 due to the contact pressure between the curved plate 19 and the inner peripheral surface of the cylinder 2, but just before the piston 1 reaches the top dead center, The stepped portion 1a is brought into contact with the locking pawl 17a upwardly, and the spring ring is brought into contact with the piston 1.
and the curved plates 19, 19 close the exhaust ports 4, 4 again. Also, just before the piston 1 reaches the bottom dead center, it presses down the contact body 12 and returns to the intake valve 7.
is opened to reach the state shown in Fig. 2, and this operation is repeated from here on.

Therefore, according to this reciprocating engine, both the intake valve 7 and the exhaust valve (spring ring 16) are automatically opened and closed in conjunction with the piston 1, and there is no need for a conventional driving means for opening and closing the valves. Become. Therefore, mechanical and thermal efficiency is high, and there is no vibration or noise unlike when a valve is opened and closed by rotation of a crankshaft, and durability can be improved. In addition, parts such as valve rods and rod cams, which are required in conventional devices, are not required, making the structure simple, compact, and lightweight, and improving reliability. Further, the curved plates 19, 19 are pressed against the inner circumferential surface of the cylinder 2 by the elasticity of the spring ring 16 and the gas pressure inside the cylinder 2, so that the exhaust ports 4, 4 can be reliably closed, and the gas pressure can be effectively used. can be used.

However, such reciprocating engines have the following problems. That is, in order to prevent the rotation of the spring ring 16, the cylinder 2
Since the guide pin 21 is provided on the inner surface of the cylindrical portion 2a, there may be sliding movement without lubrication in a low-temperature area, which may cause galling and generation of shavings. Furthermore, the slit portion of the spring ring 16 and the guide pin 21 created a large gap that adversely affected the adiabatic expansion effect, resulting in a decrease in engine performance. Furthermore, since the rotation prevention mechanism consisting of the spring ring 16 and the guide pin 21 is located inside the cylinder 2, that is, in the low temperature part,
There were problems such as maintenance and inspection being troublesome.

The present invention was made in consideration of the above circumstances, and
The purpose is to provide a reciprocating engine that is not only smaller and lighter, but also easier to maintain and inspect, and has improved engine performance and reliability.

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

FIG. 5 is a partially cutaway side view showing the main structure of an embodiment of the present invention. In addition, Figures 2 to 4
The same parts as those in the figures are given the same reference numerals, and detailed explanation thereof will be omitted. This practical example is shown in Figures 2 to 4.
The only differences from the reciprocating engine shown in the figure are the means for connecting the upper part of the piston to the piston rod and the shape of the spring ring. That is, in the center of the upper end fitting 30 of the piston 1 located in the normal temperature region, there is a bottomed hole with a non-circular, for example, rectangular cross section, which is split as shown in FIG. 31
A portion of the end 32a of the piston rod 32, which has a slightly smaller diameter than the hole 31, is fitted into this hole 31. In addition, piston rod 32
is held in a non-rotating state. The piston rod 32 is fitted with nuts 33, 3 attached to a thread 32b formed on the outer periphery of the rod 32.
4 and a locking member 35 to the upper end member 30 of the piston 1 . That is, piston 1
The piston 1 is connected to the piston rod 32 and its rotation is prevented by an anti-rotation type connecting mechanism 36 consisting of a hole 31 of the piston rod 32, an end 32a of the piston rod 32, nuts 33, 34, a locking member 35, etc. It is becoming. In addition, in the long groove 20 in the lower part of the piston 1, there is a groove 5 shown in FIG.
A guide groove 22 is formed as shown in the cross section taken along line B-B in the figure.

On the other hand, as shown in FIG. 8, the spring ring 16 is formed in an annular shape without the slit portion. Furthermore, a pin 23 is attached to the tip of the locking piece 17 in place of the locking pawl. and,
This pin 23 is inserted into the guide groove 22 of the piston 1. This allows the spring ring 16 to slide only in the axial direction of the piston 1.

With this configuration, it is possible to prevent the galling phenomenon and generation of shavings caused by the slit portion of the spring ring 16 and the guide pin 21 as in the conventional case. Furthermore, since the guide pin 21 and the slit portion that is engaged with the guide pin 21 are no longer necessary, it is possible to reduce the gap portion that adversely affects the adiabatic expansion effect. For this reason,
This has the effect of improving engine performance. Furthermore, since the anti-rotation type coupling mechanism 36 is provided in the room temperature section, there are advantages such as ease of maintenance, inspection and assembly. In addition, since the anti-rotation type coupling mechanism 36 with the above configuration is used, the cylinder 2 can be assembled without damaging the anti-rotation function.
The axial position of the piston 1 relative to the cylinder 2 can be aligned with high precision, and the characteristics of the exhaust valve, that is, the spring ring 16 sliding on the inner periphery of the cylinder 2 can be maximized. That is, an in-cylinder exhaust valve type reciprocating device has an exhaust port provided on the bottom circumferential wall of the cylinder 2, an exhaust valve that slides along the inner circumference of the cylinder 2, and an intake port provided on the bottom of the cylinder 2. The engine has substantially less dead space within the cylinder 2 than other types of engines, making it more efficient. However, this is possible only when the axial positioning of the piston 1 with respect to the cylinder 2 is performed with high precision, and if the positioning cannot be performed with high precision, the characteristics of the in-cylinder exhaust valve type cannot be exhibited. In the engine of the present invention, since the anti-rotation type coupling mechanism 36 having the above-described structure is used, the nut 33 can be tightened while the nut 34 is loosened.
By turning the piston 1, the axial position of the piston 1 relative to the cylinder 2 can be aligned extremely easily and with high precision. The anti-rotation type coupling mechanism 36 consists of a bottomed hole 31 with a rectangular cross section provided in the piston 1 and an end 32a of a piston rod 32 that is formed to have a slightly smaller diameter than the hole 31 and fits into the hole 31. Anti-rotation mechanism and threaded thread 3 formed on the outer periphery of the piston rod 32
2b, a coupling mechanism consisting of nuts 33, 34 attached to the thread 32b, and a locking member 35 for locking the nut 33 to the piston 1.

Since the piston rod 32 is held non-rotatable, the piston 1 will not rotate as long as the end 32a is fitted into the hole 31. In other words, hole 31
The rotation prevention mechanism consisting of the terminal 32a and the end 32a prevents the piston 1 from rotating relative to the piston rod 32 while allowing the piston 1 to move in the axial direction relative to the piston rod 32. . Therefore, when the nut 33 of the coupling mechanism consisting of the thread 32b, the nuts 33, 34 attached to the thread 32b, and the locking member 35 that locks the nut 33 to the piston 1 is rotated, the piston rod 32 The circumferential position of the piston 1 relative to the cylinder 2 remains unchanged, and only the axial position of the piston 1 relative to the piston rod 32 changes. Since the axial position can be aligned with high precision, it is possible to maximize the characteristics of the cylinder internal exhaust valve type.

Note that the present invention is not limited to the above-mentioned embodiments, and can be modified in various ways. For example, the outer peripheral surface of the spring ring 16 may be brought into direct contact with the inner peripheral surface of the cylinder 2, excluding the curved plates 19, 19. Furthermore, if the exhaust ports 4, 4 are made into horizontally long holes, the spring ring 16
The amount of operation can be reduced, and mechanical and thermal efficiency can be further improved. In addition, the exhaust valve is not limited to the spring ring 16, and it slides elastically against the inner circumference of the cylinder and follows the piston 1 just before it reaches the top dead center, opening the exhaust port 4, and the piston reaches the bottom dead center. Any structure may be used as long as it follows the piston and closes the exhaust port 4 just before the piston reaches the piston. Further, the intake valve 7 may be of any type as long as it is configured to open the intake port 3 in conjunction with the operation of the piston just before it reaches the bottom dead center.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the schematic configuration of a conventional Collins type reciprocating engine, and FIGS. 2 to 4 each show a schematic configuration of the reciprocating engine previously proposed by the inventors. 3 is a partially cutaway side view, 4 is a perspective view, and 5 is a partially cutaway side view.
Each of the drawings to FIG. 8 shows an embodiment of the present invention. FIG. 5 is a partially cutaway side view of the main structure of the embodiment, and FIG. 6 is a view taken along the arrow A-- A sectional view, FIG. 7 is a sectional view taken along arrow B-B in FIG. 5, and FIG. 8 is a perspective view showing the spring ring used in the above embodiment. 1... Piston, 2... Cylinder, 3... Intake hole, 4... Exhaust hole, 7... Intake valve, 16... Spring ring (exhaust valve), 31... Hole, 32... Piston rod, 33, 34...nut, 36...rotation prevention type coupling mechanism.

Claims (1)

[Claims] 1 A reciprocating engine for a refrigerator, which includes a cylinder having an intake port on the bottom wall and an exhaust port on the bottom peripheral wall, a piston housed in the cylinder so as to be able to move forward and backward, and the above-mentioned piston on the normal temperature side of the piston. Pistons arranged coaxially and non-rotating.
a non-circular bottomed hole formed on the normal temperature side of the piston, a fitting portion similar to the bottomed hole formed at the tip of the piston rod and fitted into the bottomed hole, and the piston rod. an anti-rotation coupling mechanism comprising a thread formed on the outer periphery of the screw thread and a nut attached to the thread and rotatably supported by the piston; The exhaust port elastically slides on the inner periphery of the cylinder, follows the piston just before the piston reaches the top dead center to release the exhaust port, and follows the piston just before the piston reaches the bottom dead center. an exhaust valve that normally closes the exhaust port, and an exhaust valve that normally closes the intake port, and when the piston is near the bottom dead center and within a certain range from the bottom dead center, the piston is closed. A reciprocating engine comprising: an intake valve that opens the intake port in conjunction with the intake valve.