JPS60125785A - Air compressor - Google Patents

Abstract

PURPOSE:To improve volumetric efficiency and filling efficiency by a method wherein a multitude of intake ports, arrayed on a concentric circle on the top wall of first stage piston and communicated with crank case, and specified suction valve plates, arranged at the outlet port side thereof and movable by the reciprocating motion of the piston, are provided in a compressor. CONSTITUTION:A multitude of intake ports 36, which are arrayed on a concentric circles on the top walls 15a, 15b of the first stage pistons 15A, 15B and penetrating through the top walls, are bored and valve seats 37 are formed at the side of the outlet ports thereof. The valve plates 38, movable into the reciprocating directions of the first stage pistons 15A, 15B are seated on the valve seats 37 to form suction valves. According to this method, the first stage pistons 15A, 15B are cooled by primary air in the crank case at all times to prevent the temperature rise of the pistons 15A, 15B and the deterioration of volumetric efficiency due to the preheat of the primary air while the suction valves are provided on the top walls 15a, 15b of the pistons 15A, 15B, therefore, there is no useless path as before and the filling efficiency may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The unreleased +114 relates to compressed air for special purposes such as diving breathing apparatus.

As is well known, compressed air for breathing is used when working underwater, in contaminated air, or in harmful gases, but the compression pressure of a normal air compressor is approximately 150 kg/crn' at most.
That's about it.

By the way, in recent years, high pressure compression of 200 to 300 kg/crn' has been desired for this type of air compressor due to the desire to expand the work range in water etc. and to extend the work duration. There are the following problems in realizing a high-pressure air compressor. That is, in a conventional air compressor, the piston and crank bearing are lubricated with lubricating oil stored in the crankcase, and primary air is introduced into the cylinder through a breathing valve built into the cylinder head. .

Therefore, in such a structure, when the compression ratio is increased, a portion of the lubricating oil evaporates due to the heat of compression and enters the compressed air, that is, breathing air, which may cause bronchial disorders. When an intake valve is provided in the shilling head, compressed high-temperature air remains in the passage from the intake valve to the cylinder, and this expands during the suction process, impeding the discharge efficiency.

Since the cylinder head itself undergoes a considerable temperature rise due to the heat of compression, the primary air taken in from the breathing valve is preheated, resulting in a lower volumetric efficiency. 11 I can't.

In view of the problems of conventional air compressors as described above, the present invention aims to provide a structure that has high filling efficiency and volumetric efficiency and prevents harmful evaporative gases from being mixed into the compressed air. In an air compressor that compresses air sucked in by the reciprocating motion of a piston, the primary air chamber is in the crankcase, and a number of intake ports are bored through the top wall of the piston. Air IE fl? is characterized by a ring-shaped valve plate pressed in the closing direction by a spring being seated on the J side of the bow I, and air being taken in from the crankcase. We are proposing an i-machine.

Embodiments of the invention will now be described in detail with reference to the drawings.

Fig. 1 shows an embodiment in which the present invention is applied to a tandem type three-stage air compressor, and the compressor body consists of a crankcase A with a built-in crankshaft 1, and two two-stage cylinder bores 2. 3, and a cylinder head C, in which a two-stage cylinder bore 4 and a three-stage cylinder pore 5 are formed.
, 3, 4.5 circumferential surface creeping/f knurling sleeve 6, 7.
It is covered by 8. Although not shown, one end 1a of the crankshaft l is rotated at 800 revolutions per minute by an electric motor or the like, and a pulley 9 at the other end of the crankshaft l includes a cylinder block B, a cylinder head C, and a cylinder head C (not shown). A fan belt 11 of a cooling fan 10 that cools the cooling coil with air is a hook. An intake strainer 12 is fixed to one side of the crankcase A as shown in the second diagram.
The outside air purified by the intake strainer 12 is introduced into the crankcase A. An important point about this crankcase A is that non-lubricated bearings are used for the bearing 14 between the crankshaft l and the connecting rod 13, and the bearing 18 between the connecting rod 13 and the first stage pistons +5A and 15B. As will be described later, since the piston links of the first-stage pistons 15A and 15B are specially heated, no oil is stored in the crankcase A, and the space is filled with room-temperature oil taken in from the outside. It is at the point where it is filled with air.

First stage piston +5A, 15B (7) top wall 15a, 15 reciprocating in the - stage cylinder bores 2, 3
In b, connecting rods 17 and 18 extending in the direction of the second-stage cylinder pore 4 and the third-stage cylinder pore 5 are connected to nuts 19 and 2.
It is fixed by o. A second stage piston 21 and a third stage piston 2 are fixed to the upper ends of these connecting rods 17 and 18.
2 reciprocates within the second-stage cylinder pore 4 and the third-stage cylinder pore 5, and these second-stage pistons 21 and 22 are fixed to the first-stage pistons 15A, 15B with fixing bolts 23, 24 passing through them. Therefore, when replacing the piston rings of the second-stage piston 21 and the third-stage piston 22, after removing the plugs 25 and 26 that block the rings of 71"C in the cylinder, The second stage screw I/N 21 and the third stage piston 22 can be extracted to the outside.In the illustrated embodiment, the outside air taken into the crankcase A is
5A and 15B to about 5 Kg/crn', and the second stage piston 21 compresses it to about 40 Kg/crn'.
The pressure is increased to about rn', and finally the third stage piston 22
compressed to approximately 300Kg/crn'.

In order to increase the temperature of the piston during operation of the air compressor and to maintain airtightness between it and the cylinder bore, special measures have been taken in the illustrated example of the air compressor, such that the upper ends of the first stage pistons 15A and 15B Copper alloy piston rings 27° 28, 29, 30, 31 are located on the upper end peripheral surfaces of the first, second and third stage pistons 21.22,
Heat-resistant resin seal rings 32, 33, 34,
35 is used.

In other words, piston ring 2? , 28.29.30.31
+o Piston 15A heated by compressed air,
The amount of heat of 15B and 21.22 is transmitted to the cylinder cylinder B and cylinder IJ interface FC via the liner sleeve 6°7.8 to prevent a drop in filling efficiency due to a rise in piston temperature. In addition, seal 1 nong 32, 33,
As 34 and 35, well-known Teflon rings or the like may be used, and such heat-resistant resin seal rings create a lubrication-free structure that does not seize on the lychee ring sleeve.
Become capable.

One of the features of the present invention is the structure of the intake valve for primary air, which is reduced in size as shown in FIGS. 1 and 2. That is, the top walls 15a and 15b of the first stage pistons 15A and 15B are provided with a large number of penetrating intake ports 36 arranged in concentric circles, and an annular valve seat is provided on the outlet side of these intake ports 36. 37 is formed. And for the valve seat 37,
Disk portions 17a, 18 at the base of the connecting rods 17.18
A valve plate 38 is seated on a ring movable in the reciprocating direction of the first stage pistons 5A and 15B by b, and the valve plate 38 is prevented from being pulled out by the flanges 17b and 18b of the connecting rod 17.18. It is pressed against the valve seat 37 by a weak spring 41 located in a blind hole 40 in the end face of the valve 18b.

Since the illustrated air compressor has the configuration shown below, the valve plate 38 resists the force of the spring 41 during the forward movement of the first stage pistons 15A and 15B from the top dead center to the bottom dead center. The primary air sucked into the crank case A is sucked into the first stage cylinder pores 2 and 3 through the intake port 3B, and the first stage cylinder pores 2 and 3 are opened during the forward movement stroke of the first stage pistons +5A and 15B. The air inside is compressed. In this intake stroke, since the valve plate 38 is provided on the rapidly reciprocating first stage pistons +5A and 15B, the inertia of the valve plate 38 can be used to rapidly open and close the intake valve. In addition, since the first stage pistons 15A and 15B are constantly cooled by the primary air in the crankcase A, it is possible to prevent a temperature rise in the first stage pistons 5A and 15B and a decrease in volumetric efficiency due to preheating of the primary air. The valve is the first stage piston 15A.

Since it is provided on the top wall of the 15B, there is no wasted passage like in the past, and the filling efficiency can also be improved.6 Of course, the air compressor of the present invention uses lubricating oil whose properties change or evaporate depending on the temperature of the upper layer. Because there are no chemicals, there is no harm to the human body's respiratory system.

In the above embodiments, the air compressor of the present invention can be used for gas compression in other fields.

As is clear from the above description, according to the present invention, an air compressor with both high volumetric efficiency and high volumetric efficiency can be obtained without using lubricating oil that causes high-temperature deterioration and evaporation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an air compressor according to the present invention, FIG. 2 is a sectional view taken along the line n-II in FIG. 1, and FIG. 3 is an exploded perspective view of the main parts of the air compressor. A... Crankcase, B... Schilling block, C...
Cylinder head, +5A, 15B... (first stage) piston, 15a... Top wall (of the piston). 36 ・・・・・・ Intake port, 37 ・・・・・・
Valve seat, 38... Valve plate, 41...
・Spring. Figure 2

Claims (1)

[Claims] l) In an air compressor that compresses air sucked in by the reciprocating motion of a piston, the primary air chamber is in the crankcase, and a number of intake ports are bored through the top wall of the piston, and these intake ports A ring-shaped valve plate pressed in the closing direction by a spring is seated on the first side,
An air compressor that takes air through the crankcase.