JPH08155222A - Strainer for oil opening - Google Patents

Abstract

PURPOSE: To sense a stabilized liquid level height when the reference level is lower than the position of a strainer by setting continuously a guide component on the outer section of a strainer main body and setting a rod with a float at its lower end to be lifted and lowered on the guide component. CONSTITUTION: A float 20 and a rod 21 for displaying the liquid level position connected with the float 20 are provided on the outer section of a strainer main body 9. The rod 21 is inserted into a rod inserting hole with extension sections 10a and 11a formed to protrude upper and lower mounting plates 10 and 11 of the strainer main body 9. When a strainer 6 is mounted in a manner of setting into an oil opening 5 of a tank main body 1, the float 20 is brought into contact with the liquid level and floated up securely at the liquid level lower than the reference liquid level to lift up the rod 21 when the reference liquid level in the tank main body 1 is lower than the mounting position of the strainer main body 9. An oiling person, therefore, can visualize the lifting of the rod 21 in the oiling operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided at an oil filler port of an oil tank such as a hydraulic oil tank, a fuel tank, and a lubricating oil tank of a construction machine so as to prevent impurities from entering the tank body during refueling. The present invention relates to a strainer for a fuel filler, particularly to a strainer provided with a mechanism for detecting the liquid surface position.

[0002]

2. Description of the Related Art For example, in a hydraulic oil tank of a construction machine, hydraulic oil is filled up to a predetermined liquid level height.
In order to reduce the amount of hydraulic oil due to oil leakage during use, hydraulic oil must be replenished. Also, the hydraulic oil deteriorates after a long period of use, so that it must be replaced regularly. Of course, even in oil tanks other than this, the oil is consumed, so it is necessary to replenish the oil. For this reason, the tank body is provided with a filler port, and a strainer is attached to the filler port to prevent impurities from entering the tank body when refueling via this filler port. To be done.

When the strainer is attached to the filler port,
When refueling, the height of the liquid level in the tank body cannot be confirmed from the outside. By the way, a mechanism for detecting the liquid surface position in the tank body is provided, and the liquid surface height position in the tank body can be confirmed from the outside by this detection mechanism. As this liquid level detection mechanism, there is one configured to provide a liquid level gauge on the side surface of the tank body. This liquid level gauge is composed of a thin transparent tube that guides oil in the tank body, and the liquid level in this transparent tube is configured to be at the same level as the liquid level in the tank body. However, since this liquid level gauge is located on the side surface of the tank main body apart from the oil filling port, the refueling worker cannot refuel while visually checking the liquid level gauge. There was a problem that it was not appropriate for confirming.

In consideration of the above points, by installing a liquid level height position detection mechanism on the strainer, the one in which the liquid level can be surely confirmed at the time of refueling work is actually opened. It is known from Japanese Patent Laid-Open No. 5-37309. In the liquid level detecting means disclosed in this publication, a float that floats according to the liquid level is mounted in a strainer body that constitutes a strainer, and a rod for displaying the liquid level is connected to the float. It is configured as follows. Therefore, when the liquid level rises due to refueling, the float comes into contact with the liquid level, the float floats and the rod ascends according to the rise in the liquid level, and the refueling operator visually checks the refueling port. While refueling, the height of the rod can be raised to check the liquid level. Therefore, when refueling is stopped when the rod has risen by a predetermined amount, the liquid level in the tank main body will be at an appropriate position, and there will be no inconvenience such as oil overflowing from the refueling port due to excessive refueling.

[0005]

By the way, in the float type liquid level detecting mechanism according to the prior art described above,
It has the following drawbacks.

First, since the float is located inside the strainer body, when the reference liquid level at the time of refueling is lower than the lower end portion of the strainer body, the float naturally does not float up. It is not possible to detect the liquid surface using. Generally, in a construction machine, the vehicle body may shake greatly during work, and oil may overflow from an air breather provided in, for example, a hydraulic oil tank during the operation of the machine because the work is performed on a sloping ground. There is a risk. Further, in the hydraulic oil tank, since the height position of the liquid level in the hydraulic oil tank changes depending on the state of the hydraulic cylinder as the hydraulic actuator, an air layer is interposed in the tank body of the hydraulic oil tank. In order to suppress the pressure fluctuation in the air layer portion when the liquid level rises and falls, the air layer needs to have a certain volume. From the above, the height of the maximum liquid level at the time of oil supply, that is, the reference liquid level is kept low, and for this reason, there is a considerable distance from the oil supply port to the reference liquid level. Here, although the liquid level changes depending on the state of the hydraulic cylinder as the hydraulic actuator, in general, the hydraulic cylinder keeps the working mechanism such as the boom, arm, and bucket moved by the hydraulic cylinder in a stable predetermined posture. Since the oil is supplied as described above, the maximum liquid level of the filled oil is used as the reference liquid level when the predetermined posture is achieved. In this way, when the reference liquid level is suppressed to a low level, such as in a hydraulic oil tank, in order to exert the liquid level detection function with the float, the strainer body must be moved to a position lower than the reference liquid level described above. It has to be extended, which has the drawback of making the strainer body unnecessarily long.

Further, in order to guide the rod which is connected to the float and indicates the liquid level, the guide member is supported so as to be able to move up and down, but this guide member is separate from the member constituting the strainer body. It is necessary to form the member by fixing it to the inner surface of the strainer body, which increases the number of parts and complicates the mounting structure of the guide member.

Further, at the time of refueling, since the oil is supplied into the strainer, the float is directly exposed to the flow of this oil, and the stability of the float is lost by the flow of the oil, and the float violently rises and falls. Will move.
As a result, the rod connected to the float also vibrates in the vertical direction, and there is a problem that it cannot always be detected that the reference liquid level has been reached accurately.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a strainer equipped with a mechanism for detecting a liquid surface position using a float and a rod with a simple structure. Even if the reference liquid level is lower than the strainer position, it can be reliably floated according to the liquid level height using the float, and it is stable as it is not affected by the oil flow during refueling as much as possible. It is to be able to detect the liquid level height position.

[0010]

In order to achieve the above-mentioned object, the present invention provides a tank body with an oil supply port, and from this oil supply port into the tank body, refuels up to a predetermined reference liquid level. In order to prevent impurities from entering the tank body when performing the above, a strainer body equipped with a net body and a guide member connected to the outside of the strainer body, the strainer body being installed in the filler port. The guide member is provided with a rod for indicating the liquid surface position so as to be vertically movable over a predetermined range, and the liquid surface in the tank main body has a predetermined height at the lower end portion of the rod. It is characterized in that a float that comes into contact with the liquid surface when it reaches a position and that floats in conjunction with the liquid surface is connected at least up to the reference liquid surface.

[0011]

[Function] Since the float is provided outside the strainer main body, the reference liquid level is set below the mounting position of the strainer main body by setting the rod connected to this float to an appropriate length according to the reference liquid level. Even if there is, the rod will surely start to rise from a position where the liquid level is lower than the reference liquid level. The liquid level height position can be confirmed securely. Then, for example, if a mark or the like is attached to a predetermined position of the rod, it becomes possible to detect that the inside of the tank main body has been filled with oil up to the reference liquid level with reference to this mark.

The float is not provided inside the strainer body into which the oil directly flows, but is provided outside the strainer body, so that the oil flow does not directly hit the float. As a result, the movement of the float and the rod connected to it is stabilized to some extent, and it is possible to accurately detect that the reference liquid level has been reached without undue vibration during refueling. Further, the mesh body in the strainer body is provided with upper and lower mounting plates, and a plurality of rib members are provided between the upper and lower mounting plates to form a structure, and the mesh body is fixed to the structure. I will try to provide it,
By extending the upper and lower mounting plates outward and providing the through holes for inserting the rods therein, the structure of the rod guide mechanism for displaying the liquid surface position becomes extremely simple.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the following description, the hydraulic oil tank of the construction machine will be described as an example. However, the strainer with the liquid level detection mechanism of the present invention is not limited to the fuel tank,
It goes without saying that it can also be applied to a lubricating oil tank or the like.

First, FIG. 3 shows a hydraulic oil tank of a construction machine as a tank to which a strainer is attached. In the figure, reference numeral 1 denotes a tank body of a hydraulic oil tank. A supply pipe 2 for supplying hydraulic oil to a hydraulic pump is connected to the tank body 1, and return oil from a hydraulic actuator circulates. The return pipe 3 is connected. Here, the return oil from the return pipe 3 is introduced into the tank body 1 via the filter 4. As described above, the hydraulic oil constitutes a closed circulation flow, but since there is an oil leak and the like, the amount of hydraulic oil in the entire system decreases over a long period of time. Therefore, it is necessary to periodically replenish the hydraulic oil, and when the hydraulic oil deteriorates due to long-term operation, it is necessary to replace it. For this reason, the tank body 1 is provided with the oil supply port 5. When supplying the hydraulic oil from the oil supply port 5, impurities such as foreign matter may be mixed in. Therefore, the strainer 6 is provided. The strainer 6 is used to remove impurities.

The strainer 6 has the structure shown in FIGS. 1 and 2. As is clear from these figures, the strainer 6 has a strainer body 9 composed of a structure 7 and a net body 8, and the structure 7 includes upper and lower mounting plates 10 and 11,
The net body 8 is composed of a plurality of rib members 12 provided so as to extend between the upper and lower mounting plates 10 and 11.
Is formed in a tubular shape so as to surround the. The cylindrical body may have a substantially cylindrical shape, but as shown in the drawing, it may have a frusto-conical shape that tapers downward. Furthermore, the upper and lower mounting plates 10, 1 of the net body 8
The ring member 1 is provided at a portion connected to 1 and an intermediate portion.
3 is provided. The lower mounting plate 11 is composed of a disk-shaped member having substantially the same outer diameter as the mesh body 8, while the upper mounting plate 10 is a ring-shaped member whose outer peripheral portion is the mesh body 8.
The outer diameter of the strainer body 9 is larger than the outer diameter of the oil supply port 5 and is attached so as to abut on an annular flange portion 5a fixedly provided on the inner surface of the fuel filler port 5, and the strainer main body 9 is suspended from the flange portion 5a into the tank main body 1. It is set up. Therefore, the strainer 6 is mounted so as to fit into the fuel filler port 5.
In addition, each part constituting the structure 7 can be formed by, for example, integral molding of resin, or can be separately formed and assembled, and the net body 8 can be formed by a member different from the structure 7, The structure 7 may be fixed to the structure 7, but the structure 7 and the net 8 may be integrally molded.

By the way, the amount of hydraulic oil in the tank body 1 in the hydraulic oil tank is set to be considerably smaller than the volume of the tank body 1. The reason is that the hydraulic oil is supplied as a hydraulic actuator to a hydraulic cylinder, etc., but the hydraulic cylinder has a different amount of hydraulic oil in the hydraulic cylinder when it expands and when it contracts. come. Therefore, during operation of the construction machine, the liquid level in the tank body 1 constantly changes. If the tank body 1 is filled with hydraulic oil almost completely, the pressure in the tank body 1 will fluctuate greatly when the liquid level changes. Further, during the operation of the machine, there is a risk of hydraulic oil overflowing from an air breather or the like provided in the tank body 1 because it vibrates violently and works on a considerably inclined ground. Therefore, the reference liquid level of the hydraulic oil in the tank body 1 is set to a position far away from the canopy portion of the tank body 1, for example, the liquid level position shown in FIG. Therefore, whether the hydraulic oil is replenished or replaced, the amount of oil supplied should not exceed the reference liquid level.

Since the strainer 6 is disposed at the fuel filler port 5, it is not possible to confirm the liquid level height position in the tank body 1 even if the user looks into the fuel filler port 5 through the strainer 6. A liquid level gauge 14 is provided on the side surface of the tank body 1, and the current liquid level height inside the tank body 1 can be confirmed from the outside by the liquid level gauge 14. However, although this liquid level gauge 14 can confirm whether or not replenishment of the hydraulic oil is necessary, since it is located away from the oil supply port 5, the liquid level height position at the time of actual oil supply is It is not appropriate to use it as a detection means. Therefore, if it is not necessary to always be able to confirm the liquid level height position from the outside, or if the liquid level height position can be confirmed by other means, this liquid level gauge 14 must be provided. There is no.

Therefore, the strainer 6 is provided with a detection mechanism for the liquid level height position. As for this mechanism,
Float 20 and rod 2 connected to this float 20
1 and 1. As shown in FIGS. 4 and 5, the rod 21 has extension portions 10a and 11a formed by extending a part of upper and lower mounting plates 10 and 11 constituting the strainer body 9 so as to project outward. Rod insertion holes 15 and 1
6 and therefore these rod insertion holes 15,
16 as a guide member supports the rod 21 so as to be able to move up and down. This rod 21 is longer than the axial length of the strainer body 9, and a stopper portion 21a having a diameter larger than that of the rod insertion hole 15 of the upper mounting plate 10 is fixed to the tip end portion thereof by screwing or the like. The float 20 is held by the rod 21 to a position below the lower end of the strainer body 9 by the rod 21. Thus, the length of the rod 21 is such that the float 20 is arranged at a position lower than the reference liquid level of the tank body 1 when the strainer 6 is attached to the fuel filler port 5. The upper limit position of 20 is
The position is higher than the reference liquid level. Furthermore, rod 2
1 is provided with a reference liquid level display mark 22 at a position protruding from the strainer body 9 when the float 20 floats up to the reference liquid level position. In addition, in the flange portion 5 a of the fuel filler port 5, a portion through which the rod 21 passes is recessed. Further, the fuel filler port 5 is closed by a cap (not shown).

The strainer 6 constructed as described above is
It is installed so that it fits into the fuel filler port 5, and the float 2
In the tank main body 1, 0 is floating above the liquid level, or when the liquid level is lower than a predetermined level, the stopper portion 21a of the rod 21 is located on the upper side of the strainer main body 9 which constitutes the structure 7. Extension part 10a provided on the mounting plate 10
And the float 20 is held in a suspended state.

Now, the liquid level in the tank body 1 is lowered,
When it is necessary to supply the working oil into the tank body 1 when the working oil deteriorates, the cap attached to the refueling port 5 is removed, and the working oil is supplied from the refueling port 5. Since the strainer 6 is provided at the fuel filler port 5, it is possible to prevent contaminants from entering from the outside.

When a certain amount of hydraulic oil is supplied from the oil supply port 5 and the liquid level in the tank body 1 rises to some extent, the float 20 first comes into contact with the liquid level. Therefore, after that, the float 20 floats as the liquid level rises, and as a result, the rod 21 rises. When the rod 21 starts to rise, refueling has entered the final stage, and the refueling operator can detect the final stage of refueling by confirming the position of the rod 21. Therefore, for example, when the worker performs other work while refueling, when he / she sometimes looks at the refueling port 5 and perceives that the rod 21 has started to rise, he / she can start preparing to stop refueling. . Here, the float 20 is the strainer body 9
Since the rod 21 is connected to the rod 21 longer than the entire length of the strainer main body 9 outside of the strainer main body 9, it is possible to float above the liquid level even when the liquid level does not reach the position of the strainer main body 9. Therefore, even if the reference liquid level is at a considerably low position in the tank body 1, it is not necessary to lengthen the axial length of the strainer body 9 in order to detect the reference liquid level position. .

When the rod 21 continues to rise and the mark 22 is exposed above the extending portion 10a of the mounting plate 10, the liquid level in the tank body 1 has reached the reference liquid level position. Stop refueling at the stage. As a result, it is possible to prevent the hydraulic oil from overflowing from the oil supply port 5 due to the excessive oil supply, and the hydraulic oil is accurately supplied to the reference liquid surface position. Here, since the float 20 is provided outside the strainer body 6, the flow of the hydraulic oil supplied to the oil supply port 5 does not directly act on the float 20. Therefore, the float 20 reliably raises the liquid level. Accordingly, it will float, and there will be no fear that it will violently move up and down under the influence of the flow of hydraulic oil. As a result, the liquid level can be detected based on the position of the rod 21 in a highly accurate and stable state. In particular, by forming the strainer main body 6 into a frustoconical shape that becomes narrower toward the lower side, the float 20 is arranged at a position distant from the strainer main body 6, so that the flow of hydraulic oil causes The influence can be extremely reduced.

When the refueling is finished, the refueling port 5 is covered by the cap. At this time, the rod 21 is pushed downward to immerse the float 20 below the liquid surface.
The cap makes it possible to securely apply the lid. Of course, even if the float 20 is immersed in the liquid surface, there is no particular inconvenience.

Thus, the rod 2 connected to the float 20
As a mechanism for guiding 1 in the vertical direction, the rod insertion hole 1 formed in the extending portions 10a, 11a integrally extended to the upper and lower mounting plates 10, 11 constituting the strainer body 6
Since it is formed of 5 and 16, it is not necessary to use a component for guiding the rod 21, the number of components can be reduced, and the processing is easy.

[0025]

As described above, according to the present invention, the guide member is continuously provided outside the strainer main body, and the rod is supported by the guide member so as to be vertically movable. At least the lower end portion of the rod is provided. Until the reference liquid level is reached, a float that floats in tandem with this liquid level is connected and provided, so it is possible to attach a liquid level position detection mechanism to the strainer with a simple structure, and Even if the reference liquid surface is lower than the strainer position, the float that constitutes the liquid surface position detection mechanism reliably floats up according to the liquid surface height position, and based on the rise of the rod connected to this float. As a result, the liquid level height position can be detected, and the flow of oil during refueling is not affected as much as possible, and the liquid level height position can be detected stably.

[Brief description of drawings]

FIG. 1 is an external view of a strainer according to an embodiment of the present invention in a state of being attached to a fuel filler port.

FIG. 2 is an external view of a strainer.

FIG. 3 is a cross-sectional view of a hydraulic oil tank equipped with a strainer.

FIG. 4 is a sectional view taken along line XX of FIG. 1;

5 is a cross-sectional view taken along line YY of FIG.

[Explanation of symbols]

 1 Tank Main Body 5 Oil Filling Port 6 Strainer 7 Structure 8 Net Body 9 Strainer Main Body 10, 11 Mounting Plates 10a, 11a Extensions 15, 16 Rod Insertion Hole 20 Float 21 Rod 22 Mark

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Konomura 650 Kazunachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura factory

Claims (3)

[Claims] 1. A tank is provided with an oil supply port to prevent impurities from entering the tank body when the oil is supplied from the oil supply port to the tank body up to a predetermined reference liquid level. In the strainer attached to the filler port, the strainer main body provided with a net body, and the guide member connected to the outside of the strainer main body, the rod for indicating the liquid surface position is provided in the guide member. It is provided so as to be able to move up and down over a predetermined range, and at the lower end of this rod, when the liquid level in the tank body comes to a predetermined height position, it comes in contact with the liquid level, and at least to the reference liquid level. The space between the oil tanks is a strainer for a fuel filler, which is configured such that floats that float in tandem with the liquid surface are connected and provided. 2. The strainer for a fuel filler according to claim 1, wherein the rod is provided with a reference position level display portion for displaying that the float has risen to a reference liquid surface position. 3. The strainer body has a structure composed of upper and lower mounting plates and rib members provided so as to extend between the upper and lower mounting plates, and the mesh body is fixed to the structural body. 2. The strainer for a fuel filler according to claim 1, wherein the guide member is provided on the upper and lower mounting plates.