JPS635594B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reciprocating type air compressor, that is, a type in which a piston is moved by a crankshaft and is equipped with an intake valve and a discharge valve. This invention relates to an air compressor that has a simple structure and discharges compressed air between the air and air from an intake port.

Conventionally, in air compressors, when a piston enters a downward stroke from top dead center, the piston is pushed down by the residual pressure generated by the compressed air remaining in the space formed between the top surface of the piston and the cylinder head, the so-called dead volume. As a result, the rotational speed of the air compressor is accelerated and the tooth surface of the driven gear hits the opposite side of the normally engaged tooth surface of the drive gear, causing a knocking noise between the driven gear and the driving gear. In order to prevent this phenomenon, it was necessary to exhaust the compressed air remaining in the dead volume to the outside, but this was technically quite difficult.

Furthermore, in the suction valve device and discharge valve device of the conventional air compressor, the suction valve and the discharge valve operate reciprocally against their respective compression springs.
The disadvantages are that they generate operating noise each time, are easily worn out by operation, and have relatively low durability. In addition, the timing of inhalation and exhalation is mechanically limited and cannot be changed freely, which is inconvenient.

The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and its purpose is to provide a cylinder head with a suction slit and a discharge slit that function as a suction valve and a discharge valve, respectively. By installing the formed rotary valve, the compressed air between the top surface of the piston and the cylinder head near the top dead center of the piston is discharged to the outside through the suction slit, reducing the sound of the driven gear hitting the driving gear. The objective is to reduce the operating noise of the air compressor. Another purpose is to eliminate the operating noise of the valve during inhalation and exhalation and to improve the durability of the valve. Still another object is to enable the timing of inhalation and exhalation to be freely selected.

In short, the present invention provides a cylinder in which a cylindrical hollow part is formed, a crankshaft rotatably supported by the cylinder, a piston connected to the crankshaft and fitted into the hollow part of the cylinder, An air compressor comprising: a cylinder head mounted on the upper surface of the cylinder, having a suction hole and a discharge hole communicating with the hollow part of the cylinder, and having a suction port and a discharge port open to the outside; In the cylinder head, a cylindrical hollow part is formed in the cylinder head to communicate with the suction hole and the discharge hole, and the suction port and the discharge port, respectively, and the suction hole and the suction port can communicate with each other in the hollow part. A rotary valve having a discharge slit that allows communication between the discharge hole and the discharge port is inserted into the rotary valve, and the rotary valve rotates in conjunction with the crankshaft to prevent the piston from rising when the piston is raised. The compressed air between the top surface and the cylinder head is discharged toward the air tank through the discharge hole of the cylinder head, the discharge slit of the rotary valve, and the discharge port, and the compressed air near the top dead center of the piston is discharged. It is characterized in that it is configured to be discharged to the outside through the suction hole of the cylinder head, the suction slit of the rotary valve, and the suction port.

The present invention will be explained below based on embodiments shown in the drawings. The air compressor 1 according to the present invention includes a cylinder 2, a crankshaft 3, a piston 4,
The cylinder 2 includes a cylinder head 5, a rotary valve 6, and a pressure regulating device 7. The cylinder 2 is formed in a cylindrical shape, and has a cylindrical hollow portion 2a extending vertically in the figure.

The crankshaft 3 consists of a crank pin 3a, crank journals 3b and 3c formed on both left and right sides of the crank pin in the figure, and a crank arm 3d that connects the crank journal and the crank pin 3a.
b, 3c are rotatably supported by a pair of bearings 11, 11 mounted on the crankcase 10. At the end of the left crank journal 3b, there is a driven gear 1 that meshes with a drive gear (not shown).
2 is fixed to the crankshaft 3, and in conjunction with the rotation of the driving gear, the crankshaft 3 rotates clockwise as viewed from the right side in FIG. 1 via the driven gear 12. Also crank case 10
The right crank journal 3c protrudes outward from the
A sprocket 3f is formed at the end of the small diameter portion 3e. The piston 4 is formed into a cylindrical shape, and a piston ring 13 is fitted into the outer circumferential part of the piston, and the piston ring 13 is fitted into the inner circumferential surface 2b of the hollow part 2a of the cylinder 2. Piston pin 1 supported with limited directional movement
The connecting rod 17 is connected to the crankshaft 3 by a connecting rod 17 whose both ends are fitted into the crank pin 3a of the crankshaft 3 and the crankshaft 3, respectively. Therefore, the piston 4 is configured to be able to slide vertically on the inner peripheral surface 2b of the hollow portion 2a of the cylinder 2 as the crankshaft 3 rotates.

A cylinder head 5 is mounted on the upper surface of the cylinder 2, and a cylindrical hollow part 5a with one end open is formed in the cylinder head. The cylinder head 5 also has a suction port 5b with one end communicating with the hollow part 5a of the cylinder head and the other end opening outward, and one end communicating with the hollow part 5a and the other end with an air tank (not shown). The communicating discharge ports 5c are formed in opposite directions, and the hollow portion 2a of the cylinder 2 and the hollow portion 5 of the cylinder head 5 are formed in opposite directions.
A suction hole 5d is formed which communicates with the suction port 5b through the hollow portion 5a.
Similarly, a discharge hole 5e is formed which communicates with the hollow section 2a of the cylinder 2 and the hollow section 5a of the cylinder head 5, respectively, and communicates with the discharge port 5c via the hollow section 5a.

The rotary valve 6 is composed of a main body 6a and a shaft portion 6b.The main body 6a is formed in a cylindrical shape, and an O-ring 20 is fitted into the outer peripheral surface of the main body.
The bushing 21 is press-fitted into the inner circumferential surface of the hollow portion 5a of the cylinder head 5 through the bushing 21.
Holes 21a and 21b are formed in the bush and communicate with the suction hole 5d and discharge hole 5e of the cylinder head 5, respectively. Further, on the outer peripheral surface of the main body 6a, chamfered suction slits 6d and discharge slits 6e are formed at positions that can face the suction holes 5d and discharge holes 5e of the cylinder head 5 and are on opposite sides of each other. ing. A recess 6f is formed in the left end surface of the main body 6a in the figure, and a thrust bearing 22 is embedded in the recess, and a compression spring 2 is provided between the bearing and the hollow part 5a of the cylinder head 5.
3 is accommodated so as to press and bias the thrust bearing 22. The shaft portion 6b is formed to protrude rightward from the right end surface of the main body 6a in the figure, and is fitted into a lid member 25 that is press-fitted to close the right end of the hollow portion 5a. A bearing 26 and a washer 27 are inserted into the shaft portion 6b between the lid member and the main body 6a,
The main body 6a is always pressed rightward in the figure by the compression spring 23. The crankshaft 3 is attached to the end of the shaft portion 6b that protrudes outward from the cylinder head 5.
A sprocket 6g identical to the sprocket 3f is formed, and a toothed belt 30 is mounted between these sprockets.

When the crankshaft 3 rotates, the rotary valve 6 rotates via the sprockets 3f, 6g and the toothed belt 30, and the compressed air between the top surface of the piston 4 and the cylinder head 5 when the piston 4 is raised is transferred to the discharge hole of the cylinder head. 5e and the discharge slit 6e of the rotary valve 6 from the discharge port 5c to an air tank (not shown), and compressed air between the top surface of the piston 4 near the top dead center of the piston 4 and the cylinder head 5 is transferred to the suction hole of the cylinder head. 5d and a suction slit 6d of the rotary valve 6, and is configured to be discharged to the outside from the suction port 5b.

The pressure regulating device 7 includes a regulating valve 32,
The control valve is rotatably disposed between a hole 33 communicating with the suction hole 5d and a hole 34 communicating with the suction port 5b, and has a communication hole 32a bent at a right angle. It is configured so that the holes 33 and 34 are communicated or closed by rotation, and when the pressure of the compressed air in the air tank exceeds a certain value, an actuator (not shown) such as an air cylinder or an electromagnetic solenoid is activated. When activated, the control valve 32 is rotated to a position that allows the holes 33 and 34 to communicate with each other. Of course, the control valve 32 may be in the form of a relief valve having a valve spring or the like.

The present invention is configured as described above, and its operation will be explained below. When the driven gear 12 is rotated by the drive gear, the crankshaft 3 rotates, and the piston 4 slides vertically on the inner peripheral surface 2b into the hollow part 2a of the cylinder 2 via the connecting rod 17, and the rotary valve 6 is rotated. It rotates via sprockets 3f, 6g and toothed belt 30. At the beginning of the upward stroke of the piston 4, as shown in FIGS. 4 and 5, the suction hole 5d and the suction port 5b, and the discharge hole 5e and the discharge port 5c.
are in a state where they are not in communication with each other through the rotary valve 6. Therefore, the air stored in the space 2c of the cylinder 2 between the upper surface of the piston 4 and the cylinder head 5 is As it rises, it is compressed and the pressure gradually increases. When the piston 4 further rises, the discharge slit 6e rotates to a position where the discharge hole 5e and the discharge port 5c communicate with each other, as shown in FIG. Compressed air is sequentially discharged into the air tank from the discharge port 5c. In this state, the suction slit 6d is in the sixth position.
As shown in the figure, since the suction hole 5d and the suction port 5b are located at a position where they do not communicate with each other, compressed air does not escape from the suction port 5b.

When the piston 4 further rises, the rotary valve 6 rotates, and the piston 4 reaches about 20 degrees before the top dead center, the suction slit 6 opens as shown in FIG.
d rotates to a position where the suction hole 5d and the suction port 5d are communicated with each other, and the compressed air in the space 2c of the cylinder 2 is discharged from the suction port 5b. In this state, the discharge slit 6e is in a position where the discharge hole 5e and the discharge port 5c communicate with each other, as shown in FIG.
e and the discharge port 5c are rotated to a position where they do not communicate with each other.

Therefore, for each rotation of the crankshaft 3,
The compressed air in the space 2c of the cylinder 2 near the top dead center of the piston 4 is discharged from the suction port 5d via the suction hole 5d and the suction slit 6d, so the residual pressure in the space 2c of the cylinder 2 is The sound of the driven gear 12 hitting the drive gear is reduced considerably, and the operating noise of the air compressor 1 can be reduced.

Further, when the air tank is filled with compressed air and the pressure of the compressed air exceeds a certain value, the actuator is activated and the control valve 32 is rotated to a position where the holes 33 and 34 are communicated with each other, and the compressed air is transferred between the holes 33 and 34. hole 3
Since air is discharged to the suction port 5b through the air tank 2a and the hole 34, and is sucked in from the suction port 5b through the hole 33, the communication hole 32a, and the hole 34, the pressure inside the air tank does not exceed a certain value. When the pressure in the air tank falls below a certain value, the control valve 32 is rotated to a position where the holes 33 and 34 are not communicated with each other, so that the air compression action when the piston 4 is raised is not hindered in any way. Note that the control valve 32 may be electrically operated as a solenoid valve.

After the top dead center of the piston 4, as the piston moves downward in the direction of arrow B, the space 2 of the cylinder 2
c becomes a vacuum state, and air flows into the space 2c of the cylinder 2 through the suction port 5b, the suction slit 6d and the suction hole 5d, as shown in FIG. In this case, the discharge slit 6e has been rotated to a position where the discharge hole 5e and the discharge port 5c do not communicate with each other, as shown in FIG.

Since the present invention is constructed and operates as described above, a rotary valve having a suction slit and a discharge slit that functions as a suction valve and a discharge valve, respectively, is mounted on the cylinder head. The compressed air between the top surface of the piston and the cylinder head near the top dead center of the piston is discharged from the suction port through the suction slit, reducing the sound of the driven gear hitting the driving gear and reducing the operating noise of the air compressor. It has the effect of being able to Further, there is no valve operation noise during suction and discharge, resulting in improved durability. Further, since the positions of the suction slit and the discharge slit of the rotary valve can be changed freely, there is an effect that the timing of suction and discharge can be freely selected.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an air compressor according to the present invention, FIG. 2 is a perspective view of a rotary valve, and FIG.
The figure is a vertical cross-sectional view taken in the direction of the - arrow in Fig. 1, Figs. Vertical sectional views showing the mutual relationship of the rotary valve, suction hole, and suction port at the beginning of the upstroke, during the piston upstroke, about 20° before the piston top dead center, and at the piston downstroke, Figures 5 and 7
Figures 9 and 11 are shown at the beginning of the piston upward stroke, during the piston upward stroke, and approximately before the piston top dead center, respectively.
FIG. 3 is a vertical sectional view showing the mutual relationship of the rotary valve, the discharge hole, and the discharge port at 20 degrees and during the piston downward stroke. 1 is an air compressor, 2 is a cylinder, 3 is a crankshaft, 4 is a piston, 5 is a cylinder head, 5a, 5b, 5c, 5d, and 5e are hollow parts of the cylinder head, suction port, discharge port, and suction hole, respectively. , discharge hole, 6 is rotary valve, 6
d and 6e are a suction slit and a discharge slit of the rotary valve, respectively.

Claims (1)

[Claims] 1. A cylinder in which a cylindrical hollow part is formed, a crankshaft rotatably supported by the cylinder, a piston connected to the crankshaft and fitted into the hollow part of the cylinder, and an upper surface of the cylinder. In the air compressor, the air compressor is equipped with a cylinder head, which is attached to the cylinder head and has a suction hole and a discharge hole, respectively, which communicate with the hollow part of the cylinder, and has a suction port and a discharge port, which are open to the outside, respectively. A cylindrical hollow part is formed in the head and communicates with the suction hole and the discharge hole, and the suction port and the discharge port, respectively, and a suction slit that allows the suction hole and the suction port to communicate with each other; A rotary valve having a discharge slit that allows communication between a discharge hole and the discharge port is inserted into the rotary valve, and the rotary valve rotates in conjunction with the crankshaft, and the upper surface of the piston and the cylinder when the piston is raised are inserted into the rotary valve. The compressed air between the heads is discharged toward the air tank through the discharge hole of the cylinder head, the discharge slit of the rotary valve, and the discharge port, and the compressed air near the top dead center of the piston is discharged to the cylinder head. An air compressor characterized in that the air compressor is configured to discharge to the outside through the suction hole of the rotary valve, the suction slit of the rotary valve, and the suction port.