JPS5912405Y2 - air engine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air engine for driving an oil pump or the like.

As a conventional air engine, there is one shown in FIG.

This communicates the compressed air supplied to the air supply port 2 of the switching valve 1 to the left side chamber 4 of the cylinder 3, pushes the piston 5 inside the cylinder 3 toward the cloth, and further opens by the movement of the piston 5 and opens the left side chamber 4 of the cylinder 3. The compressed air is supplied from the port 6 to the left recess 8 of the spool 7 of the switching valve 1 to move the spool 7 to the right, and by switching the spool 7, the compressed air from the air supply port 2 is transferred to the right chamber 9 of the cylinder 3 compressed air is supplied to the right recess 11 of the spool 7 from the right port opened by the leftward movement of the piston 5, and the spool 7 is moved leftward. Then, the spool 7 and the piston 5 are repeatedly caused to interfere with each other, and the rod 12 of the piston 5 is moved.
It is designed to obtain continuous reciprocating power.

Note that in this Figure 1, 13, 14. 15 is an exhaust port.

In the conventional air engine shown in FIG. 1, in order to prevent the piston 5 and the spool 7 from being in the neutral position and the spool 7 not moving at the time of starting, the left and right flanges of the spool 7 are connected to each other. The diameters of the portions 7a and 7b are made different so that the spool 7 moves preferentially in the direction of the 7 flange portion 7a having a larger diameter.

However, in practice, even if the spool 7 is in a completely neutral position, if the air supplied to the air supply port 2 is allowed to leak into the supply and discharge ports 18 and 19 of the switching valve 1, the flow of air can be reduced to As a result of this effect, the flow becomes bistable and flows reliably toward either the supply/discharge port 18 or 19, so even if the left and right flange portions 7a,
Even if the diameters of the spools 7b are the same, the compressed air in the air supply port 2 will be forced into either the left or right chambers 4, 9 of the cylinder 3, so the diameters of both flanges 7a, 7b of the spool 7 will be There is little need to make them different.

In addition, in this conventional structure in which the diameters of both the left and right flanges 7a and 7b are different, the force with which the compressed air presses the spool 7 to the left in FIG. Therefore, even when this spool 7 is located at the right end and the compressed air is forced to be sent from the supply/discharge port 19 to the right side chamber 9 of the cylinder 3 to move the piston 5 to the left, this piston 5 is not connected to the right side port 10. There is a risk that the spool 7 will be switched to the left by the different radial pressure and the compressed air will be sent to the left chamber 4, causing the spool 7 and the piston 5 to become stuck.

This possibility tends to occur when the pressure of compressed air is high.

Moreover, this conventional spool 7 has a structure in which it slides against the switching valve main body while maintaining airtightness not only on the outer peripheral surfaces of the flange portions 7a and 7b but also on the left and right recesses 8 and 11, so that the frictional resistance during sliding is reduced. There is a dog point that is large and there is a large possibility that it will not move.

Moreover, with this conventional air engine (h exhaust ports 1
3, 14, and 15, and due to manufacturing reasons, the diameters of the flange portions 7a and 7j of the spool 7 are different, and recesses 8 and 11 are provided on the left and right sides, and the spool mounting hole is stepped in the switching valve body. It is not preferable to form a convex portion that fits into the concave portions 8 and 11 airtightly and accurately.

Furthermore, conventionally, there is a cylinder operated by compressed air shown in Minoko Publication No. 42-14889, which has a switching valve with four land type spools and three exhaust ports. If four lands are provided on the spool, there will be restrictions in making the switching valve compact, and the spool shape cannot be made simple.
For these reasons, it is easy to limit the size of the air engine as a whole, and it is also disadvantageous in processing and manufacturing.

Furthermore, when there are three exhaust ports, it is a hassle to prepare and install three exhaust mufflers to reduce exhaust noise.

The present invention has been developed in view of these points, and aims to ensure that the air engine continues to operate smoothly, to combine the exhaust ports into one, and to make the switching valve structure compact and simple, making it easy to manufacture. The purpose is to

An embodiment of the present invention will be described based on FIGS. 2 to 6.

A piston 23 having a concave groove 22 on the outer circumferential surface is fitted into the cylinder 21 so as to be able to move forward and backward, and the rod 24 fixed to the piston 23 is pulled out through the center of one end of the cylinder 21, and oil is applied to the pulled-out part. Connect a load such as a pump.

The piston 23 defines a left chamber 25 and a right chamber 26 on the left and right sides of the cylinder 21.

Further, an exhaust port 27 is provided in the center of the cylinder 21, and spool switching pressure supply and discharge ports 28 and 29 are provided on the left and right sides, and piston drive pressure supply and discharge ports 31 and 32 are provided on the left and right end surfaces of the cylinder 21, respectively. Piston 23
are in contact with the left and right inner ends of the cylinder 21.
1, one of the spool switching pressure supply/discharge ports 28 or 29 is positioned so as to communicate with one of the piston drive pressure supply/discharge ports 31 or 32, and the other spool switching pressure supply/discharge port 29 or 28 is located in a concave groove of the piston 23. It is positioned so as to communicate with the exhaust port 27 via the exhaust port 22.

Further, the spool 43 is loosely fitted into the valve body 42 of the switching valve 41 so that it can move forward and backward with a slight play.

A concave groove is provided on the outer peripheral surface of this spool 43, and flange portions 45 of the same diameter are provided at the left and right ends. 46 is provided.

In addition, an air supply port 47 is provided in the center of the valve body 42, and piston drive pressure supply and discharge ports 49 are provided on the left and right sides,
In addition, the spool switching pressure supply/discharge port 5 is located on the left and right end surfaces of the valve body 42.
1 and 52 respectively, and with the spool 43 in contact with the left and right inner ends of the valve body 42, one piston drive pressure supply/discharge port 51 or 49 of the valve body 42 is connected to one spool switching pressure supply/discharge port 51 or 49. 52, and the other piston drive pressure supply/discharge port 49 or mallet is located so as to communicate with the air supply port 47 via the concave groove of the spool 43.

The left and right spool switching pressure supply and discharge ports 28 and 29 of the cylinder 21 and the left and right spool switching pressure supply and discharge ports 51 and 52 of the switching valve 41 are respectively connected to conduits 53. 54, and the left and right piston drive pressure supply and discharge ports 31 and 32 of the cylinder 21 and the left and right piston drive pressure supply and discharge ports 48 of the switching valve 41. 49 are connected through conduits 55 and 56, respectively.

Then, compressed air from the compressor is supplied to the air supply port 47 of the switching valve 41, and as shown in FIG. The switching valve 41 is opened from the left side supply/discharge date 28 of the cylinder 21, which is opened by the rightward movement of the piston 23.
The compressed air is supplied to the left end supply/discharge port 51 to move the spool 43 to the right as shown in FIG.
The compressed air is discharged from the exhaust port 27 of the cylinder 21 through the groove 22 of the cylinder 21, and the compressed air from the air supply port 47 is supplied to the right chamber 26 of the cylinder 21 by switching the spool 43 to the right, as shown in FIG. The piston 23 is pushed to the left, and at this time, the air in the left chamber 25 of the cylinder 21 passes through the pipe 55, the switching valve 41, the pipe 53, and the concave groove 22 of the piston 23 in sequence, and is discharged from the exhaust port 27. , and further the piston 23
5, the spool 43 is moved to the left by supplying compressed air from the right side lead outlet 29 of the cylinder 21, which is opened as shown in FIG. At this time, the air on the left side of the spool 43 flows through the pipe 53.
The compressed air is discharged from the exhaust port 27 of the cylinder 21 through the concave groove 22 of the piston 23, and the compressed air from the air supply port 47 is supplied to the left chamber 25 of the cylinder 21 by switching the spool 43 to the left. The piston 23 is moved to the right as shown in FIG. This operation in which the piston 23 and the spool 43 interfere with each other is repeated to obtain continuous reciprocating power from the rod 24 of the piston 23.

Note that even if the spool 43 is completely located at the neutral position at the time of startup, the air supplied to the air supply port 47 will flow through the flange portion 45 of the spool 43. The air leaks to the supply/discharge ports 48 and 49 of the switching valve 41 through the play of the switching valve 46, and the air flow becomes a bistable flow due to the Coanda effect and flows reliably toward either the supply/discharge port 48 or 49. Therefore, this spool 43 will surely start oscillating.

In addition, by taking into account the pressure reduction in the chamber 25 or 26 due to the adiabatic expansion work during the switching process of the piston 23 and the leakage, the switching valve 41 is set to a width increase factor of 1 or more, which allows low-speed operation similar to the multivibrator circuit. even at the time spool 43
The vibration can be sustained without stopping at a neutral position, that is, a dead point.

According to the present invention, since the flanges at both ends of the spool in the switching valve have the same diameter, the spool smoothly receives the pressure of only the compressed air supplied from the left and right spool switching pressure supply/discharge ports on its end face. The switching valve vibrates permanently, and with the spool in contact with the left and right inner ends of the valve body, the piston drive pressure supply/discharge date is aligned with the spool switching pressure supply/discharge date, and the piston and spool advance and retreat. Since the exhaust associated with this can be carried out through a single exhaust port provided in the cylinder, only one exhaust muffler is required to be attached to this exhaust port to reduce exhaust noise. The exhaust port structure is simple and easy to manufacture, and since the switching valve is provided so that the piston drive pressure supply/discharge port and the spool switching pressure supply/discharge port can communicate with each other, the above-mentioned supply/discharge port can be easily operated like a traditional air engine. It is easier to process or shape than a spool with a structure that maintains airtightness during discharge, and the spool has two flanges of the same diameter compared to a conventional switching valve that has a four-land spool. A structure that allows you to use Because of this, the spool and valve body can be made compact, and their shapes can be made simple, which allows the entire air engine to be made smaller, and is also advantageous in terms of manufacturing, making it suitable for mass production.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional air engine, FIG. 2 is a sectional view showing an embodiment of the air engine of the present invention, and FIGS. 3 to 6 are sectional views illustrating its operation. 21... Cylinder, 22... Concave groove, 23... Piston, 24... Rod, 27... Exhaust port J2B,
29... Spool switching pressure supply port, 31, 32...
・Piston drive pressure supply/discharge port, 41...Switching valve, 42・
...Valve body, 43...Spool, shaver...concave groove, 45
, 46-...Flange part, 47...Air supply port, Tsukuda, 4
9...Piston drive pressure supply/discharge port, 51, 52...
Supply port for spool switching pressure.

Claims (1)

[Scope of utility model registration request] A piston with a concave groove on the outer circumferential surface is fitted into the cylinder, a rod is fixed to this piston, a load is connected to this rod, an exhaust port is provided in the center of the cylinder, and the spool is switched between the left and right sides. A piston driving pressure supply and discharge date is provided at the left and right ends of the cylinder, and the spool switching pressure supply port on one side of the cylinder is opened with the piston in contact with the left and right inner ends of the cylinder. One of the piston drive pressure supply and discharge ports is positioned so as to communicate with the other, and the other spool switching pressure supply and discharge port is located so as to communicate with the exhaust port through the concave groove of the piston, and the switching valve A spool is fitted into the inside of the valve body so as to be freely advanced and retracted, a concave groove is provided on the outer peripheral surface of the spool, flange portions of the same diameter are provided on the left and right ends, and an air supply port is provided in the center of the valve body. Supply/discharge dates for piston driving pressure are provided on the left and right sides, and supply/discharge dates for spool switching pressure are provided on the left and right ends of the valve body, respectively. With the valve body in contact with the left and right inner ends of the valve body, the piston drive pressure supply and discharge ports on one side of the valve body are positioned so as to communicate with the spool switching pressure supply and discharge ports on the other side, and the piston drive pressure supply and discharge ports on the other side The opening is positioned so as to communicate with the air supply port through the concave groove of the spool, and the left and right spool switching pressure supply and discharge ports of the cylinder are respectively connected to the left and right spool switching pressure supply and discharge ports of the switching valve, An air engine characterized in that the left and right piston drive pressure supply and discharge ports of the cylinder are connected to the left and right piston drive pressure supply and discharge ports of the switching valve, respectively.