JPH0433427Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a large-sized air compressor with an improved suction valve.

``Prior Art'' In a conventional air compressor, as shown in FIG. A rectangular suction valve plate 5 is located on the diameter line of the cylinder 1 and is attached at one end in a cantilever shape (reed valve shape), and the suction hole 6 can be opened and closed by this suction valve plate 5. At the same time, a rectangular discharge valve plate 7 is attached to the upper surface of the valve seat plate 3 in a cantilever shape (reed valve shape) with one end fixed like the suction valve plate 5. It is known that the discharge hole 8 can be opened and closed by means 7. When the suction hole 6 is opened, the tip of the suction valve plate 5 is spaced apart from the suction hole 6 and is locked in a recess 9 formed on the top edge of the cylinder side wall, thereby ensuring that the suction valve plate 5 operates reliably. I'm starting to do that.

In the suction stroke, when the piston 10 moves from the top dead center toward the bottom dead center, the suction valve opens, and as a result, the outside air flows into the cylinder head 4 into a suction chamber separated from the discharge chamber 11 by the partition wall 4a. When the piston 10 moves from the bottom dead center toward the top dead center during the compression stroke, the suction valve closes and the air inside the cylinder 1 reaches a predetermined pressure. When the discharge valve opens, high-pressure air passes through the discharge hole 8 and is sent out from the discharge chamber 11 to an air tank (not shown) via piping connected to the discharge chamber 11. In addition, 13 is a piston ring, 14
is the cylinder chamber.

"Problem that the invention aims to solve" By the way, in a small air compressor, the number of revolutions of the crankshaft that reciprocates the piston 10 is high, but the stroke of the piston is small, and the flow velocity of the air flowing through the suction valve is relatively low. Therefore, a cantilever-shaped rectangular suction valve plate 5 that corresponds to the suction hole with a small flow path area is suitable for this small air compressor, and the suction valve has low operating noise and is durable.
It has excellent features such as good operation followability, small gap volume, and low cost.

However, for medium and large air compressors,
Although the cylinder diameter is large and the rotation speed of the crankshaft that operates the piston is slightly lower than that of a small air compressor, the piston stroke is large.
In addition, it is not possible to make the suction valve plate's follow-up performance too bad, so it is not possible to increase the lift amount of the suction valve plate. When a suction valve plate is used, there is a problem that the air flow path area is insufficient, air resistance becomes excessive, and compression performance deteriorates.

This invention was made in view of the above circumstances,
It is an object of the present invention to provide an air compressor having a suction valve that can obtain a sufficient flow passage cross-sectional area and prevent deterioration of compression performance even when used in a medium to large-sized air compressor.

"Means for Solving the Problems" The present invention has the following configuration in order to achieve the above object. That is, both ends of the suction valve body made of a band-shaped plate having a curved portion in the middle are positioned approximately on the diameter line of the cylinder of the compressor, and the portion of the suction valve body that undergoes substantial flexural deformation is located in the projected space of the cylinder. The cylinder is located inside the cylinder, and at least one portion of the curved portion is provided with a projection that engages with the cylinder side wall.

"Operation" According to the above configuration, both end sides of the suction valve body are linear, so the rigidity of the suction valve body is increased, and the portion of the suction valve body that undergoes substantial flexural deformation is placed within the projection space of the cylinder. Since the suction valve body is provided with a protrusion that engages with the cylinder side wall, it improves the operational followability of the suction valve body without increasing the lift amount of the suction valve body, and also prevents the gap volume from increasing. This makes it possible to increase the cross-sectional area of the suction air flow path, thereby improving compression performance.

"Embodiment" An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In this embodiment, parts with the same names as those in the conventional example are given the same reference numerals, and their explanations will be omitted.

This embodiment is intended for medium to large-sized air compressors. Three suction holes 22 are formed in the valve seat plate 21 so as to be located above a portion of the cylinder chamber 14 along the inner circumferential surface of the cylinder 1 and facing the cylinder chamber 14 and the suction chamber 12. These suction holes 22 are formed in the shape of long holes and are spaced apart from each other with some distance. On the lower surface of the valve seat plate 21, a portion where the suction valve plate 23, which is a substantially dogleg-shaped suction valve plate 23 made of a band-shaped plate with a curved portion in the middle, is substantially deformed, is placed in the projection space of the cylinder 1. That is, the suction valve plate 23 is provided facing the cylinder chamber 14. This suction valve plate 23 has a curved intermediate portion, and a protrusion 24 that is engaged with a recess 9 formed on the top surface of the cylinder side wall is provided in the curved intermediate portion. Both end sides of the suction valve plate 23 are linear. The suction valve plate 23 is located below each suction hole 22, and both ends of the suction valve plate 23 are located on the diameter line of the cylinder 1, and bolts 25 are attached to the lower surface of the valve seat plate 21 near the inner wall surface of the cylinder 1. Fixed by The vicinity of both ends of the suction valve plate 23 and the head of the bolt 25 are accommodated in a relief recess 1a formed at the upper edge of the cylinder 1. Each suction hole 22 and the suction valve plate 23 constitute a suction valve. The amount of lift of the suction valve plate 23 is regulated by the distance H shown in FIG. 2, that is, the depth of the recess 9. The distance between the outer edge of the curved portion of the suction valve plate 23 (suction valve plate edge on the inner wall surface side of the cylinder 1) and the inner wall surface of the cylinder 1 is a distance marked G shown in FIG. The lift amount H of the valve plate 23 is greater than or equal to the lift amount H of the valve plate 23.

Furthermore, four discharge holes 26 are formed in the valve seat plate 21 so as to face the cylinder chamber 14 and the discharge chamber 11 . These discharge holes 26 are located on both sides of the diameter line of the cylinder 1 in the direction orthogonal to the partition wall 4a, and are provided close to each other on the diameter line.

On the other hand, four valve receiving plates 27 and four discharge valve plates 28 are respectively provided on the upper surface of the valve seat plate 21 in a stacked state substantially parallel to the partition wall 4a. The base end portion is fixed to the valve seat plate 21 with bolts 29. The valve receiving plate 27 is the valve seat plate 21
It has a hole that is part of the discharge hole 26. The discharge hole 26 can be opened and closed by a discharge valve plate 28, and the discharge hole 26 and the discharge valve plate 28 constitute a discharge valve.

In addition, 30 is a bolt for tightening the valve seat plate 3 to the cylinder head 4, and 31 is a bolt for tightening the valve seat plate 21 to the cylinder 1.
and bolts for attaching the cylinder head 4.

According to this embodiment, the suction valve has a fixed beam characteristic in which both ends of the suction valve plate are fixed to the valve seat plate, and a cantilever beam characteristic in which one end of the suction valve plate is fixed and the other end is a free end. Since the suction valve plate 23 has a composite characteristic of It has high rigidity, and since the suction valve plate 23 is in a dogleg shape and a projection 24 that engages with the cylinder side wall is provided on the curved part,
A plurality of elongated suction holes 22 along the inner wall of the cylinder
can be provided, the cross-sectional area of the suction air flow path becomes larger, the compression performance is improved, and the suction valve plate 2
There is no need to sacrifice air suction performance by making the lift amount particularly large or small, so the operational followability is good, the gap volume can be reduced, and it is suitable for medium and large air compressors. It can be widely applied to machines to improve their performance.

Note that when using an unloader mechanism that opens the suction valve using a push rod when the discharge pressure reaches a specified value, when the head of the piston 10 reaches the top dead center, the piston head In order to avoid contact with the suction valve plate 23 pushed down by the push rod of the unloader mechanism, it may be necessary to provide an approximately dogleg-shaped relief groove on the top surface of the piston corresponding to the suction valve plate 23. In this case, However, the gap volume does not need to be so large, and the gap volume can be made smaller than when using a ring-shaped suction valve plate, which is generally used in large air compressors.

``Effect of the invention'' According to the invention, both ends of the suction valve body made of a band-shaped plate having a curved part in the middle are located approximately on the diameter line of the compressor cylinder, so both ends of the suction valve body Since the part is straight, the rigidity of the suction valve body is high, and the part of the suction valve body that undergoes substantial flexural deformation is located within the projection space of the cylinder, and at least one part of the curved part is engaged with the cylinder side wall. Since the mating protrusion is provided, it is possible to improve the operational followability of the suction valve plate without increasing the amount of lift of the suction valve plate, and it is also possible to prevent the gap volume from increasing, and to prevent the suction air from increasing. This makes it possible to increase the cross-sectional area of the flow path, and it can be widely applied to medium- to large-sized air compressors to improve their compression performance.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the present invention. Figure 1 is a cross-sectional plan view, Figure 2 is a sectional view taken along the - line in Figure 1, and Figure 3 is a conventional air compressor. FIG. 2 is a vertical sectional view of the main parts of the machine. 1... Cylinder, 9... Recess, 10... Piston, 21... Valve seat plate, 22... Suction hole, 23...
Suction valve plate, 24...protrusion.

Claims (1)

[Scope of utility model registration request] A suction valve body made of a band-shaped plate material having a curved portion in the middle is provided with both ends positioned approximately on the diameter line of the cylinder of the compressor, and a portion of the suction valve body that undergoes substantial flexural deformation is placed within the projection space of the cylinder. An air compressor, characterized in that a protrusion is provided at at least one location of the curved portion to engage with a cylinder side wall.