JP3731141B2 - Lubricating oil level detection device for air compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention detects the oil level by detecting whether or not an appropriate amount of lubricating oil is retained in a compressor of a system that supplies the lubricating oil stored in the crank chamber of the reciprocating air compressor by a splash oil supply method. The present invention relates to an improvement in a lubricating oil level detection device for a splash oil supply type air compressor, which is managed by issuing an alarm or the like when the level drops.
[0002]
[Prior art]
In an oil supply type air compressor, it is necessary to always supply an appropriate amount of lubricating oil to each sliding part. If the lubricating oil is not supplied, the sliding part will be seized or damaged, and compression will occur. It will be a major accident leading to damage to the machine body. There are various types of lubrication oil supply methods, but in general-purpose reciprocating air compressors, a splash oil supply method with a simple configuration is often used.
[0003]
In the splash oil supply type, lubricating oil is stored in a crank chamber, and splashes of lubricating oil are generated by oil scraping blades that rotate with a connecting rod attached to the crank. It is supplied to the moving part. If the lubricant is not supplied, seizure and damage as described above will occur, so daily confirmation of the amount of lubricant and replenishment of lubricant are important tasks.
[0004]
Conventionally, this has been done manually every day using an oil inspection rod or the like. However, in order to rationalize this work, a lubricating oil detection device (oil level sensor) is often provided in the compressor.
[0005]
This lubricant detection device is also described, for example, in Japanese Utility Model Publication No. 3-35897 related to the application of the present applicant.
[0006]
4 and 5 are longitudinal sectional views of main parts of a lubricating oil detection device of a conventional splash oil supply type air compressor. In both figures, (1) is a crank chamber that serves as a storage chamber for compressor elements such as a connecting rod and a crankshaft. Near the bottom of the crank chamber (1), there is a boss portion (1a) for attaching a lubricant detecting device. It is formed outward. (2) is a float type oil level detecting device main body, and its mounting cylinder (3) is screwed into the boss portion (1a) of the crank chamber (1). That is, a female screw is formed on the inner periphery of the boss portion (1a), and a male screw that can be screwed into this screw groove is formed on the outer surface of the mounting cylinder (3). The level detection device main body (2) and the mounting cylinder (3) are fixed by bolts (5) via a seal member (4).
[0007]
Further, the level detection device main body (2) and the mounting cylinder (3) are provided with communication holes (2a) and (3a), respectively, so that the inside of the crank chamber (1) and the level detection device main body (2) are separated. , They are communicated so as to have the same pressure. A float (7) that moves up and down in accordance with the oil level of the lubricating oil (6) stored in the crank chamber (1) is disposed in the level detection device body (2). When the value falls below the lower limit, an alarm or a shutdown of the compressor is performed.
[0008]
Next, the operation will be described. When the piston of the compressor is driven to reciprocate, the oil scraper blade (8) attached to the connecting rod (9) scoops up the lubricating oil (6) and generates splashes. ) Is sent to each sliding part in the crank chamber (1). At this time, the splash of the lubricating oil (6) lifted up by the oil scraping blade (8) adheres to the inner surface of the wall of the crank chamber (1) and becomes an oil film and oil drops. And those that fall directly on the oil level.
[0009]
When the oil film and oil droplets scatter toward the inner wall of the crank chamber (1) on the level detection device (2) mounting side, the air communicating between the chamber of the level detection device (2) and the crank chamber (1) is communicated. The passage (10a) and the air hole (10b) are closed by the dropped oil film, and a sealed chamber is formed in the level detection device (2).
[0010]
In the reciprocating compressor, the air pressure in the crank chamber becomes higher than the normal atmospheric pressure due to the back pressure due to the reciprocating motion of the piston, and the pressure constantly fluctuates. When the air chamber in the level detection device (2) is hermetically sealed, there is a difference between the air pressure due to back pressure in the crank chamber (1) and the air pressure above the oil level in the level detection device (2). It becomes impossible to accurately detect the oil level in the crank chamber (1).
[0011]
That is, when the air passage (10a) and the air hole (10b) are in communication, the air pressure in the crank chamber (1) and the pressure in the level detection device (2) are the same, and the oil level is also the same. However, if the air passage is blocked in this state, the air pressure in the level detection device (2) remains as it is. In this state, when the air pressure in the crank chamber (1) decreases due to the compression pressure of the compressor, fluctuations in the rotational speed, etc., the oil in the level detection device (2) is caused by the residual pressure in the level detection device (2). The surface is significantly lower than the oil level in the crank chamber (1), and exceeds the lower limit of the appropriate oil level, causing alarms and troubles in shutdown.
[0012]
Conversely, when the air pressure in the crank chamber (1) is high, even if the lubricating oil level in the crank chamber (1) falls below the lower limit, the oil level in the level detector (2) does not drop, Therefore, there is a risk of causing an accident without issuing a signal such as an alarm even though the lubricating oil is insufficient.
[0013]
As described above, when the air passage (10a) and the air hole (10b) communicating between the crank chamber (1) and the level detection device (2) are closed by the oil film generated by the splash, A pressure difference occurs at the boundary, and the oil level in the level detection device (2) cannot be accurately detected. This phenomenon occurs when the number of formations of the sealed chamber surrounded by the oil film increases, and as the air pressure fluctuates due to the back pressure of the crank chamber (1) due to repeated load operation and no-load operation of the compressor, The frequency of occurrence of pressure difference increases.
[0014]
When this phenomenon occurs, it is actually detected that the oil level is at the lower limit even though the amount of lubricating oil in the crankcase (1) is within the appropriate range, and an alarm, shutdown, etc. Will result in malfunction. Therefore, conventionally, a bypass pipe is attached between the crank chamber (1) and the level detection device main body (2) from the outside, and both are connected, or as shown in FIG. It was attached to the mounting cylinder (3).
[0015]
[Problems to be solved by the invention]
Since the conventional lubricating oil level detection device (2) for the spray supply type air compressor has the above-described configuration, it has the following problems.
[0016]
One is that if the air pressure difference between the crank chamber (1) and the level detector (2) that occurs during compressor operation is eliminated by connecting an external bypass pipe, Since it protrudes to the outside of the chamber and the level detection device main body is attached to the tip of the chamber, it is easily damaged when the compressor is moved, and its installation work is troublesome.
[0017]
As shown in FIG. 5, the shield plate (10) is attached with bolts (11), etc., and air holes (10b) are provided in the crank chamber to change the role of the bypass pipe. It is possible that the air hole (10b) of the shielding plate (10) looks into the crank chamber (1) and the splash of lubricating oil falls and the air hole (10b) is closed by the oil film. In addition, an increase in the unit cost of parts and the number of assembling steps is unavoidable by attaching a separate device.
[0018]
The present invention has been made paying attention to such problems of the conventional one, and provides a lubricating oil level detection device for an air compressor that can prevent malfunction of the device with a simple configuration. It is aimed.
[0019]
[Means for Solving the Problems]
According to the present invention, the above problem is solved as follows.
(1) Lubricating oil (6) is stored and communicated with the crank chamber (1) of the air compressor, and the level detecting device main body (2) of the lubricating oil (6) is directly connected to the outer surface of the crank chamber (1). in the lubricating oil level detection device of the splash lubrication air compressor comprising mounting said crankcase air chamber in (1) and (24), an air guide that communicates the air chamber (25) in the level detection device body (2) a passage (21), so that tip the crank chamber (1) horizontally protrudes into, and the crank chamber (1) in the lubricating oil from the tip (6) does not enter, the distal end opening surface (20c) , it is assumed that the amount projecting toward downward consist vent tube shall become small (20b), further the air chamber in the crankcase (1) (24) and vent tube (20b), the level detection device body ( 2 ) is formed integrally with a seal packing (20) for attaching to the side wall of the crank chamber ( 1 ) .
[0020]
(2) In the above item ( 1 ) , the seal packing (20a) and the vent pipe (20b) are integrally formed of rubber or elastic polyurethane resin.
[0021]
[Action]
Lubricating oil stored under the crankcase is sprinkled by oil scraping blades provided so as to protrude from the lower end of the connecting rod during compression operation, and it is splashed and adheres to the wall surface etc. of the crank chamber. It flows down. At that time, since the air conduction path communicating with the crank chamber and the level detection device chamber protrudes from the wall of the crank chamber on the lubricating oil liquid level, the oil film flowing down from the wall flows around the pipe and flows into the air. It does not block the opening of the conduction path.
[0022]
Moreover, since the opening surface of the air conduction path faces downward, the falling oil droplet does not enter from the opening surface. Therefore, the air pressure in the level detector and the crank chamber follows the pressure fluctuation in the crank chamber without closing the air conduction path, and both are always at the same pressure, resulting in a difference in the liquid level between the two. There is nothing. For this reason, the oil level detection device accurately detects the oil level in the crank chamber, and there is no possibility that the level detection device malfunctions.
[0023]
In addition, a seal packing that connects the level detector to the crankcase body so that there is no leakage of lubricating oil, and a vent pipe are integrally molded, and it is made of rubber or resin with rubber elasticity. At the same time, it is possible to ensure the proper amount of protrusion and the downward direction of the opening surface of the vent pipe even when setting, without worrying about the direction and the length of protrusion.
[0024]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a principal part showing a lubricating oil level detection device for an air compressor according to the present invention, and the same components as those in FIGS. 4 and 5 are denoted by the same reference numerals.
[0025]
In FIG. 1, (1) is the crank chamber of the compressor, (1a) is the boss part, (2) is the level detection device body, (2a) is the communication hole, (7) is the float, (23) is the float The switch set (20) is an adapter packing in which a seal packing (20a) and an air conduction path pipe (20b) are integrally formed, and (21) is an air conduction path.
[0026]
As shown in FIGS. 2 and 3, the adapter packing (20) protrudes toward the inner upper edge of the annular seal packing (20a) in the axial direction and the tip surface (20c) downwards. The base end part (20d) of the ventilation pipe (20b) having an inclined surface with a small diameter is integrally attached.
The inside of the ventilation pipe (20b) is an air conduction path (21).
[0027]
The adapter packing (20) is preferably integrally molded from rubber or polyurethane resin having rubber elasticity .
Only through the trachea (20b), and formed with a metallic, a seal packing (20a) may be integrally molded formed shape.
[0028]
The cross section of the vent pipe (20b) is not limited to a circular shape, and the tip end surface thereof is not limited to an inclined surface as long as it faces in the direction of the seal packing (20a), and may have another shape.
[0029]
The adapter packing (20b) integrally molded in this manner sandwiches the seal packing (20a) between the side wall of the level detection device main body (2) and the boss portion (1a) of the crank chamber (1). Thus, the seal packing (20a) can be tightened with the front end surface (20c) of the vent pipe (20b) facing downward.
[0030]
The level detection device main body (2) is attached to the boss portion (1a) of the crank chamber (1) with two bolts by a flange (not shown) attached to the level detection device main body (2). The lubricating oil (6) communicates with the inside of the level detection device main body (2) through the oil conduction path (28). The boss portion (1a) is provided with a hole for inserting the vent pipe (20b) above the oil conduction path (28).
[0031]
(26) and (27) indicate the upper and lower limits of the lubricating oil level, respectively. When the float (7) goes up and down between these upper and lower limits and falls below the lower limit (27), the float switch (23) is turned on and a signal is sent to the alarm device or the operation stop device. The float switch (23) is attached to the lid (22) of the level detection device main body (2). The air chamber (25) of the level detection device main body (2) and the interior (25) of the crank chamber (24) communicate with each other through an air conduction path (21).
[0032]
Next, the operation will be described. When the compressor is operated and the crankshaft (not shown) rotates, the lubricating oil (6) is lifted up by the oil scraper blade (8) attached to the lower part of the connecting rod (9), and splashes are generated. The splash of the lubricating oil (6) is supplied to each sliding portion in the crank chamber (1).
[0033]
There are two types of splashes of the lubricating oil (6), one that hits the wall surface in the crank chamber (1) and flows down as an oil film, and the other that falls directly on the oil surface. If the vent pipe (20b) does not protrude, the air conduction path (21) is blocked by the oil film flowing down, and the air pressure in the crank chamber (24) and the inner chamber (25) of the level detection device main body (2) are blocked. Since the communication is cut off, the air pressure in the crank chamber that constantly fluctuates due to back pressure or the like in the crank chamber (1) is not transmitted, the air pressure in both chambers becomes different, and the lubricating oil level in both chambers becomes different. .
[0034]
However, according to the present invention, since the vent pipe (20b) protrudes inward of the crank chamber (1), the oil film flows down along the outer periphery of the vent pipe (20b), and the air conduction path (21) is blocked. It will never be done. In addition, the oil droplet from which the splashed splash directly falls is directed so that the oil droplet does not directly enter the air conduction path (21) because the opening surface of the vent pipe (20b) is directed downward. The vent pipe (20b) has a sufficient inner diameter and is not blocked by an oil film.
[0035]
When the adapter packing (20) formed integrally in this way is set in the crank chamber (1), the spigot provided in the boss portion (1a) of the crank chamber (1) and the air conduction passage hole are provided. Just by fitting, the protruding amount and the downward direction of the opening surface are accurately set, and at the same time, the seal packing is set, so that the level detecting device main body is not attached and the lubricating oil does not leak.
[0036]
As another embodiment, the same effect can be obtained by using an eaves-like cover (not shown) obtained by cutting off the lower half of the front end surface of the vent pipe (20b) of the adapter packing (20) formed integrally.
[0037]
As described above, according to the present invention, when the lubricating oil level detection device is directly attached to the crank chamber of the splash oil supply type air compressor, it is only necessary to set the adapter packing in which the seal packing and the ventilation pipe are integrally formed. , There is no risk of closing the air passage due to the oil film flowing down from the wall of the crank chamber or directly falling oil droplets, and the air pressure in the lubricating oil level detection device and the crank chamber is always the same pressure, the oil level in both chambers Therefore, it is possible to reliably prevent malfunction of the apparatus.
[0038]
The integrally formed adapter packing is a very inexpensive part compared to the conventional separate one, and the above effect can be obtained just by setting this one part, reducing the number of compressor assembly steps. the can be Rukoto.
[0039]
In the above description, the float switch is taken as an example of the level detection means, but the same effect can be obtained by using another level detection means, for example, a level detection device using an electrode rod.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of an adapter packing formed by integrally forming a seal packing and a vent pipe.
FIG. 3 is an AA arrow view in FIG. 2;
FIG. 4 is a longitudinal sectional view of an essential part showing a conventional example.
FIG. 5 is a longitudinal sectional view of a main part showing another conventional example.
[Explanation of symbols]
(1) Crank chamber
(1a) Boss
(2) Level detector body
(2a) Communication hole
(3) Mounting cylinder
(3a) Communication hole
(6) Lubricating oil
(7) Float
(8) Oil shaving blade
(9) Connecting rod
(10) Shield plate
(10a) Air passage
(10b) Air hole
(11) Bolt
(20) Adapter packing
(20a) Seal packing
(20b) Vent pipe
(20c) Tip opening surface
(20d) Base end
(21) Air conduction path
(22) Lid
(23) Float switch set
(24) (25) Air chamber
(26) Upper limit of lubricant level
(27) Lower limit of lubricant level
(28) Oil conduction path

Claims (2)

Lubricating oil (6) is stored and communicated with the crank chamber (1) of the air compressor, and the level detecting device main body (2) of the lubricating oil (6) is directly attached to the outer surface of the crank chamber (1). In the lubricating oil level detection device of the splash oil supply type air compressor,
The air chamber in the crankcase (1) and (24), the horizontal air chamber in the level detection device body (2) and (25) an air conduction path communicating (21), the tip crankcase (1) in the project, and as the crank chamber (1) in the lubricating oil from the tip (6) does not enter, the distal end opening surface (20c), the vent tube projecting amount toward downward is assumed to be small ( consisted of 20b), further the crank chamber (1 air chamber in) and (24) vent pipe (20b), the level detection device body (2) seal packing for attachment to a side wall of the crankcase (1) ( 20) Lubricating oil level detection device for an air compressor formed integrally . A vent tube seal packing (20a) (20b) and the lubricating oil level detection device of an air compressor according to claim 1 wherein formed by integral molding such as a polyurethane resin having a rubber or elastic.

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