JP3498259B2 - Unload valve for air compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unload valve for an air compressor.

[0002]

2. Description of the Related Art Conventionally, in an air compressor, a plate-shaped intake valve for sucking air into a compression chamber is forcibly opened by an unload valve to reduce the load at startup. It is known that (for example, Japanese Utility Model Laid-Open No. 58-120887).

[0003]

However, the unload valve 101 used in the conventional air compressor.
As shown in FIG. 2E, the front end surface 103 has a flat shape. Therefore, as shown in FIG. 2 (F), the intake valve 105 that is slightly bulged outward by the internal pressure of the compression chamber.
However, there is a problem that the intake valve 105 is abutted in a point contact state, a large stress is generated in the intake valve 105 due to a concentrated load, and the durability of the intake valve 105 is reduced.

Therefore, an object of the present invention is to provide an unload valve for an air compressor which does not impair the durability of the intake valve.

[0005]

The unload valve for an air compressor of the present invention made to achieve the above object forcibly pushes open a plate-shaped intake valve for sucking air into a compression chamber. The unload valve for an air compressor provided for this purpose is characterized in that a recess is formed in the tip end surface that presses the intake valve.

According to this unload valve for an air compressor, since the concave portion is formed in the tip end surface, when the intake valve is pressed, the unload valve and the intake valve are in line contact with each other by the peripheral edge of the concave portion. Abut. Therefore, the load applied to the intake valve becomes a distributed load due to the peripheral edge of the recess, and the stress applied to the intake valve is reduced. As a result, the durability of the intake valve can be improved.

Here, in this unload valve for an air compressor, it is preferable that the recess be formed by a spherical recess. With such a configuration, the unload valve and the intake valve come into contact with each other by the entire spherical recess, further reducing the stress applied to the intake valve and further improving the durability of the intake valve. Because you can

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. As shown in FIG. 1, the cylinder head 1 of the air compressor according to the embodiment includes a compression chamber 9 surrounded by a cylinder 3, a piston 5, and a valve plate 7.
Is equipped with. The valve plate 7 is provided with an intake hole 11 for sucking atmospheric air into the compression chamber 9, and a discharge hole 13 for discharging the air compressed in the compression chamber 9 to an air tank (not shown). Here, the intake hole 11 is closed by a plate-shaped intake valve 15 which opens and closes by the vertical movement of the piston 5, and the discharge hole 13 is similarly closed by a plate-shaped discharge valve 17 which opens and closes by the vertical movement of the piston 5. It is blocked.

An unload valve 19 is arranged near the intake valve 15 so as to face the intake hole 11.
The unload valve 19 is provided to reduce the load at the time of starting by moving down when the air compressor is stopped and pushing the intake valve 15 open. In the present embodiment, as shown in FIG. 2 (A), the unload valve 19 has a front end surface 21 provided with a recess 23 formed of a circular hole. As a result, when the intake valve 15 is pushed open by the unload valve 19, the unload valve 19 and the intake valve 15 are in contact with each other at the peripheral edge of the recess 23, as shown in FIG. 2B. .

Next, the unload valve 1 of the present embodiment
The action and effect of using 9 will be described with reference to the graph of FIG. FIG. 3 shows the unload valve 19 of the embodiment.
The results of calculation of the stress value generated when the intake valve 15 is pressed are shown for the case of using the unloading valve of FIG. The dotted line in the figure shows the case of the conventional example, and the solid line shows the case of the embodiment. As is clear from this figure, according to the unload valve 19 of the embodiment, the maximum stress generated in the intake valve 15 is at the position of the peripheral edge of the recess 23, and the value thereof is half or less of that in the conventional example. As a result, according to the unload valve 19 of the embodiment, the durability of the intake valve 15 can be significantly improved.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various other embodiments can be adopted without departing from the scope of the invention. Of course.

For example, as shown in FIG. 2 (C), an unload valve 30 having a spherical recess 31 on the entire tip surface may be used. In this case, when the intake valve 15 is pressed, the entire front end surface of the unload valve 30 comes into surface contact with the intake valve 15 as shown in FIG. As a result, the stress value applied to the intake valve 15 becomes smaller and the durability can be further improved.

[0013]

As described above, according to the present invention, it is possible to provide an unload valve for an air compressor that does not impair the durability of the intake valve.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of an air compressor according to an embodiment.

FIG. 2 is a cross-sectional view showing a tip shape of an unload valve of an embodiment, a modified example and a conventional example and a contact state with an intake valve.

FIG. 3 is a graph comparing stress values generated in the intake valve between the case where the unload valve of the embodiment is used and the case where the conventional unload valve is used.

[Explanation of symbols]

1 ... Cylinder head, 9 ... Compression chamber, 11 ...
Intake hole, 13 ... Discharge hole, 15 ... Intake valve, 17 ...
..Discharge valves, 19 ... Unload valves, 21 ...
Tip surface, 23 ... Recess, 30 ... Unload valve, 31 ... Spherical recess.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference Japanese Patent Publication Sho 60-27833 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F04B 39/10

Claims (2)

(57) [Claims] 1. An unload valve for an air compressor, which is provided for forcibly opening a plate-shaped intake valve for sucking air into a compression chamber, wherein a recess is formed in a tip end surface for pressing the intake valve. An unload valve for an air compressor, which is characterized by being formed. 2. The unload valve for an air compressor according to claim 1, wherein the recess is formed by a spherical recess.