JPH062667A - Unload device for air compressor - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the wear of the tip of the unload piston of the air compressor. [Configuration] Valve body 11 of suction valve 7 (reed valve) of air compressor
The cylinder portion 12 is provided on the cylinder head 4 so as to face the above. An unload piston 20 is slidably and rotatably fitted in the cylinder portion 12. The unload piston 20 is provided with an air passage 24 having a spiral groove 26 on the side wall. Pipe fitting
Compressed air is introduced into the cylinder portion 12 from 15 to slide the unload piston 20 and the rod portion 23 pushes open the valve element 11 to bring it into an unloading state. At this time, the compressed air hits the spiral groove 26, and as the unload piston 20 slides, the air flows in the air passage 24 and the unload piston
Rotational force occurs at 20. By this rotational force, the unload piston 20 slides while rotating, so that the contact portion 22 and the stopper portion 14 do not hit the rod portion 23 and the valve body 11 one-sided, and the Uneven wear is prevented and wear is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an air compressor unloading device.

[0002]

2. Description of the Related Art An example of a conventional unloader for an air compressor will be described with reference to FIGS.

FIG. 5 shows a cylinder head portion 1 of a reciprocating air compressor. As shown in FIG. 5, in the cylinder head portion 1, a cylinder head 4 is attached to an upper portion of a cylinder 2 that forms a compression chamber via a valve seat member 3, and inside the cylinder head 4, there is an atmosphere side. A suction chamber 5 communicating with the discharge chamber 6 and a discharge chamber 6 communicating with the tank are provided. The valve seat member 3 allows air to flow from the suction chamber 5 into the cylinder 2 and prevents air from flowing in the opposite direction, and allows air to flow from the inside of the cylinder chamber 2 to the discharge chamber 6. However, a discharge valve 8 (see FIG. 6) that prevents the flow in the opposite direction is provided.

The suction valve 7 has a valve hole 9 for communicating the suction chamber 5 with the inside of the cylinder 2, one end of which is attached to the cylinder 2 side end surface of the valve seat portion seat 3 by a bolt 10 and the other end is a free end. A reed valve including a flexible valve body 11 that opens and closes the valve hole 9. When the air flows from the suction chamber 5 into the cylinder 2, the valve body 11 bends to open the valve hole 11. For flow in the opposite direction, the valve body 11 is pressed against the valve seat member 3 and
It is supposed to close 11.

Next, the unloading device will be described.
A cylinder portion 12 is formed on the cylinder head 4 so as to face the valve hole 9 of the valve seat member 3.
The unload piston 13 is slidably fitted. The unload piston 13 projects from one end side of the cylinder portion 12 into the suction chamber 5 and extends to the vicinity of the valve seat member 3,
A rod portion 13a, which is inserted into the valve hole 9 and comes into contact with the valve body 11, is provided at the tip portion thereof so as to project therefrom. The valve hole 9 of the valve seat member 3 is provided with a stopper portion 14 that abuts against the abutment portion 13b of the unload piston 13 on the tip end side to restrict the movement thereof toward the valve body 11 side. On the other end side of the cylinder portion 12, a plug 16 to which a pipe joint 15 is attached is attached. A spring 17 for urging the unload piston 13 toward the plug 16 is provided in the cylinder portion 12.

The pipe joint 15 is connected to an air tank (not shown) via an unload governor (not shown) or a solenoid valve (hereinafter referred to as a solenoid valve) so that the pressure in the air tank reaches a predetermined pressure. Then, the solenoid valve or the like operates to introduce the compressed air in the air tank into the cylinder portion 12. In the figure, 18a and 18b are seal members and 19 is a piston.

With this structure, the unload piston 13 is normally provided with the spring 17 on the plug 16 side (upper side in FIG. 5).
Since the rod portion 13a does not press the valve body 11, the suction valve 7 can be freely opened and closed. Therefore, due to the reciprocating movement of the piston 19, the air sucked into the cylinder 2 from the suction valve 7 is compressed, sent to the discharge chamber 6 side, and stored in the air tank.

When the pressure in the air tank reaches a predetermined pressure, a solenoid valve or the like operates to introduce the compressed air in the air tank into the cylinder portion 12. The pressure of the compressed air causes the unload piston 13 to slide toward the valve seat member 3 side (downward in FIG. 5), the contact portion 13b abuts the stopper portion 14 of the valve seat member 3, and the rod portion 13a. Forcibly pushes the valve element 11 open, so that the suction valve 7 is constantly opened and brought into an unloading state.

[0009]

However, in the above-mentioned conventional unloading device, when switching to the unloading state, when the rod portion 13a of the unloading piston 13 abuts on the valve body 11 and pushes it open, The same portion of the rod portion 13a of the unload piston 13 is always in contact with the body 11. Therefore, uneven wear due to one-sided contact occurs, and the valve opening amount of the valve element 11 decreases, resulting in a problem of impairing the unloading function. In the case where the valve hole 9 also serves as the stopper portion 14 of the unload piston 13 as in the conventional structure, the contact portion 13b of the unload piston 13 has the stopper portion 14 of the valve seat member 3. Wears due to abutting against. At this time, since the contact portion 13b of the unload piston 13 contacts the stopper portion 14 in a fixed direction, uneven wear due to one-sided contact occurs in a hatched portion in FIG. If the wear of the contact portion 13b of the unload piston 13 increases,
Since the sliding amount of the unload piston 13 becomes large, the load applied to the valve body 11 by the rod portion 13a when the valve body 11 is pushed open becomes large and the valve body 11 is easily damaged.

The present invention has been made in view of the above points, and it is an object of the present invention to reduce the wear of the tip portion of the unload piston.

[0011]

In order to solve the above-mentioned problems, the present invention comprises an unload piston that comes into contact with the valve body of the suction valve, and a cylinder into which the unload piston is slidably fitted. An unloading device for an air compressor that introduces compressed air into the cylinder to slide the unload piston to press the valve body and forcibly open the suction valve to bring it into an unload state. In the above, the unload piston is provided with a rotational force generating means for receiving a compressed air introduced into the cylinder to generate a rotational force.

[0012]

With this structure, when compressed air is introduced into the cylinder, the unloading piston slides and rotates by the rotational force of the rotational force generating means, so uneven wear does not occur without uneven contact. There is nothing to do.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. Since the unloading device of the present embodiment differs from the conventional example shown in FIG. 5 only in the unloading piston, the same members as those shown in FIG. The details will be described.

As shown in FIGS. 1 and 2, the cylinder portion
The unloading piston 20, which is slidably and rotatably fitted in the 12, has a pressure receiving surface 21 formed on one end side and an abutting portion on the other end side.
A rod portion 23 (tip portion) is provided so as to protrude from 22. And
Similar to the conventional example shown in FIG. 5, the contact portion 22 abuts on the stopper portion 14 of the valve seat member 3 to restrict the movement toward the valve body 11, and the rod portion 23 pushes the valve body 11. It is supposed to open.

The unload piston 20 is provided with an air passage 24 extending from the pressure receiving surface 21 to the vicinity of the contact portion 22 along the axis thereof as a rotational force generating means. An end portion of the air passage 24 on the contact portion 22 side is opened to a side surface portion of the unload piston 20 via a small passage 25. A spiral groove 26 is formed on the side wall of the air passage 24 along the axis thereof.

The operation of the present embodiment configured as described above will be described below.

Similarly to the conventional example shown in FIG. 5, the unload piston 20 is normally moved to the plug 16 side (upward in FIG. 1) by the spring 17, and the rod portion 23 does not press the valve body 11. The suction valve 7 can be freely opened and closed. Therefore, the reciprocating motion of the piston 19 causes the suction valve 7
The air sucked into the cylinder 2 from is compressed, is sent to the discharge chamber 6 side, and is stored in the air tank.

When the pressure in the air tank reaches a predetermined pressure, a solenoid valve or the like operates to introduce the compressed air in the air tank into the cylinder portion 12. The pressure of the compressed air causes the unload piston 20 to slide toward the valve seat member 3 side (downward in FIG. 5), the abutting portion 22 abuts on the stopper portion 14 of the valve seat member 3, and the rod portion 23. Forcibly pushes the valve element 11 open, so that the suction valve 7 is constantly opened and brought into an unloading state.

At this time, the compressed air introduced into the cylinder portion 12 hits the spiral groove 26 of the air passage 24, and the rotational force is generated by the air flow in the air passage 24 caused by the sliding of the unload piston 20. And the unload piston 20
Slides while rotating in the cylinder portion 12. For this reason,
The contact portion 22 and the rod portion 23 of the unload piston 20 are
While changing its direction, the stopper portion 14 and the valve body 11 of the valve seat member 3 are brought into contact with each other and do not come into one-side contact, so that the contact portion 22 and the rod portion 23 are not unevenly worn, and the wear thereof is prevented. Decrease.

The unload piston 20 according to this embodiment is
For example, as shown in FIG. 3 and FIG. 4, as a rotational force generating means, one end side is opened to the pressure receiving surface 21, and the other end side is opened to the side surface portion through a passage 27a extending substantially along the circumferential direction of the unload piston 20. It is also possible to provide an air passage 27 for controlling. In the figure, 28 and 29 are plugs.

In this case, the compressed air is introduced into the cylinder portion 12 or the compressed air flows in the air passage 27 as the unloading piston 20 slides.
Since a rotational force is generated by the air flowing in the circumferential direction of the unload piston 20 from the opening, the unload piston 20 slides in the cylinder portion 12 while rotating. Therefore, similarly to the above, it is possible to prevent uneven contact of the unload piston 20 and reduce wear.

In addition to the above-mentioned means, the rotational force generating means of the unload piston 20 may be a blade or an unevenness provided on the pressure receiving surface 21 and receiving compressed air to generate a rotational force.

[0023]

As described above in detail, the unloading device of the air compressor of the present invention, when compressed air is introduced into the cylinder, the unloading piston slides and the rotation force generating means rotates. Since it rotates by force, it does not hit one side and uneven wear does not occur. As a result, there is an excellent effect that the wear of the unload piston can be reduced and the durability can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a cylinder head portion of an air compressor to which an embodiment of the present invention is applied.

2 is an enlarged side view of the unload piston of the device of FIG.

FIG. 3 is a vertical cross-sectional view of a side surface of an unload piston according to another embodiment of the present invention.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a vertical cross-sectional view of a cylinder head portion of an air compressor including a conventional unloading device.

6 is a plan view of the valve seat member of the apparatus of FIG.

FIG. 7 is an enlarged view of a contact portion between the stopper portion and the unload piston of the valve seat member of the apparatus shown in FIG.

[Explanation of symbols]

 7 Suction valve 9 Valve hole 11 Valve body 14 Stopper part 12 Cylinder part (cylinder) 20 Unload piston 23 Rod part (tip part) 24,27 Air passage (rotational force generating means)

Claims (2)

[Claims] 1. An unload piston that comes into contact with a valve body of a suction valve, and a cylinder that slidably fits the unload piston, and introduces compressed air into the cylinder to provide the unload. In an unloading device of an air compressor that slides a piston to press the valve element to forcibly open the suction valve to bring it into an unloading state, compressed air introduced into the cylinder in the unloading piston. An unloading device for an air compressor, which is provided with a rotational force generating means for receiving a rotational force to receive the rotational force. 2. An unload piston whose tip portion is inserted into a valve hole of the suction valve and abuts on a valve body of the suction valve, a cylinder into which the unload piston is slidably fitted, and the valve hole. And a stopper portion that abuts on the unload piston and regulates the sliding amount thereof, and introduces compressed air into the cylinder to slide the unload piston to press the valve body. In an unloading device of an air compressor for forcibly opening a suction valve to bring it into an unloading state, the unloading piston is provided with a rotational force generating means for receiving a compressed air introduced into the cylinder and generating a rotational force. An unloader for an air compressor, which is characterized in that