JP6838507B2 - Oil level gauge - Google Patents

Description

The present invention relates to an oil level gauge for an industrial vehicle.

In industrial vehicles such as forklifts, oil level gauges are used to measure the amount of oil in the oil chambers of engines and transmissions. The oil level gauge is inserted into the insertion port of the guide tube that communicates with the oil chamber, and the oil level gauge is pulled out from the insertion port when measuring the amount of oil.

In addition, the pressure in the oil chamber may become negative with respect to the atmospheric pressure depending on the operating conditions of the industrial vehicle. When the oil chamber becomes negative pressure, not only is it difficult to pull out the oil level gauge due to the pressure difference from the atmospheric pressure, but also when the air and the oil chamber communicate with each other by pulling out the oil level gauge, the guide tube is inserted due to the pressure difference. Water or foreign matter accumulated around the mouth may enter the oil chamber.

Therefore, for example, Patent Document 1 has been proposed as an oil level gauge for releasing the pressure in the oil chamber to the atmosphere.
As shown in FIG. 8, the oil level gauge of Patent Document 1 is composed of a gauge body 90 for measuring the oil level by adhering oil to the tip and a handle portion 91 made of a rubber-like elastic material. A breather groove B for communicating the oil pan (oil chamber) and the atmosphere is formed in the handle portion 91. Further, a film portion 92 integrated with the handle portion 91 is formed in the middle of the breather groove B. The film portion 92 is deformed by a predetermined pressure difference to release the pressure in the oil pan to the atmosphere and eliminate the negative pressure. On the other hand, in a state where a predetermined pressure difference does not occur, the film portion 92 suppresses water or foreign matter that has entered the breather groove B from entering the oil pan.

Japanese Unexamined Patent Publication No. 2012-031812

However, in the configuration of Patent Document 1, when the inside of the oil pan becomes negative pressure and a predetermined pressure difference occurs, the film portion 92 is deformed, and water or foreign matter invades into the oil pan.
The present invention has been made to solve the above problems, and an object of the present invention is to provide an oil level gauge capable of suppressing the intrusion of water or foreign matter into the oil chamber due to the negative pressure of the oil chamber. ..

The oil level gauge for solving the above problems is integrated with the gauge body inserted into the oil chamber from the insertion port and the gauge body, and when the gauge body is inserted into the insertion port, the insertion port is inserted. In an oil level gauge of an industrial vehicle having a sealing material for sealing, the sealing material has a first passage forming portion formed by cutting into the outer peripheral surface of the sealing material and the first passage forming portion. Is provided with a second passage forming portion in which one end is connected to the oil chamber and the other end communicates with the oil chamber, and the first passage forming portion is not affected by an external force associated with pulling out the gauge body from the insertion port. It is a gist that the air chamber and the oil chamber communicate with each other through the first passage forming portion and the second passage forming portion that are opened and opened when the external force acts on the oil chamber.

According to this configuration, since the first passage forming portion is closed when the oil level gauge is not pulled out, even if the oil chamber has a negative pressure, the first passage forming portion and the second passage forming portion are used. Water and foreign matter are prevented from entering the oil chamber. On the other hand, when the oil level gauge is pulled out, the external force accompanying the pulling out acts on the oil level gauge, and the external force also acts on the sealing material. Then, the first passage forming portion opens, and the first passage forming portion communicates with the second passage forming portion, so that the atmosphere and the oil chamber communicate with each other. If the oil chamber has a negative pressure, the oil chamber is opened to the atmosphere due to the pressure difference from the atmosphere, and the negative pressure in the oil chamber can be eliminated.

Further, regarding the oil level gauge, the sealing material is provided with a contact surface that comes into contact with the periphery of the insertion port, and the first passage forming portion is located at a position higher than the contact surface of the sealing material. is there.
According to this configuration, the contact surface of the sealing material comes into contact with the periphery of the insertion port, so that the gauge body is arranged at a predetermined position where the amount of oil in the oil chamber can be measured. In this configuration, the area around the outlet is a deposit surface on which water and foreign matter are likely to accumulate. However, since the first passage forming portion is located at a position higher than the contact surface of the sealing material, the first passage forming portion can be arranged at a position away from the deposition surface, and the first passage is formed. It is easy to suppress the invasion of foreign matter into the portion, and the invasion of foreign matter into the oil chamber through the first passage forming portion and the second passage forming portion can be further suppressed.

According to the present invention, it is an object of the present invention to provide an oil level gauge capable of suppressing the invasion of water or foreign matter into the oil chamber due to the negative pressure of the oil chamber.

Side view of the forklift. The schematic diagram which shows the installation state of the oil level gauge in an engine. (A) is a front view of the oil level gauge of the first embodiment with the first passage forming portion closed, and (b) is 3B-3B of FIG. 3 (a) with the first passage forming portion closed. Line end view. (A) is a front view of the oil level gauge of the first embodiment with the first passage forming portion open, and (b) is 4B-4B of FIG. 4 (a) with the first passage forming portion opened. Line end view. The end view which shows the oil level gauge of the 2nd Embodiment. (A) is a front view showing a first passage forming portion of another example, and (b) is an end view of line 6B-6B of FIG. 6A showing another example of the first passage forming portion. (A) is a front view showing a first passage forming portion of another example, and (b) is a 7B-7B line end view of FIG. 7A showing another example of a first passage forming portion. Sectional drawing of the main part of the oil level gauge in the prior art.

(First Embodiment)
Hereinafter, a first embodiment embodying an oil level gauge for an industrial vehicle will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, the forklift 1 as an industrial vehicle is provided with a driver's seat 3 substantially in the center with respect to the traveling direction of the vehicle body 2. The fork 4 exists in the direction of advancing the vehicle body when viewed from the driver's seat 3.

The forklift 1 includes an engine 6, a torque converter 7, a PTO (power take-off) unit 8 and a transmission 9 under the enshin hood 5.
As shown in FIG. 2, the engine 6 includes an oil chamber 16 for storing oil necessary for operating the engine 6. Although not shown, the transmission 9 also includes an oil chamber 16.

The operation of the forklift 1 causes a temperature change in the oil chamber 16, and a pressure difference is generated between the pressure in the oil chamber 16 and the atmospheric pressure. When the oil chamber 16 has a positive pressure, the breather (not shown) provided in the oil chamber 16 controls the oil chamber 16 so that the pressure does not exceed a certain level. On the other hand, when the oil chamber 16 has a negative pressure, the breather does not control the negative pressure. Therefore, the oil chamber 16 may have a negative pressure.

The forklift 1 includes an oil level gauge 17 that measures the oil level of the oil in the oil chamber 16.
The oil level gauge 17 is inserted into a guide tube 18 provided in the cylinder block of the engine 6 and a guide tube 18 provided in the case of the transmission 9. The guide tube 18 includes an insertion port 22 that opens at the upper end. The portion of the guide tube 18 below the insertion port 22 extends to the oil chamber 16. The guide tube 18 has a tubular shape. The oil level gauge 17 is inserted into the guide tube 18 so that the gauge body 19 described later is inserted in the direction from the oil surface toward the oil. Further, the guide tube 18 is provided with a locking surface 18a around the insertion port 22. The locking surface 18a is recessed from the upper end surface 18b of the guide tube 18.

As shown in FIGS. 3A and 3B, the oil level gauge 17 is composed of a gauge body 19 and a sealing material 20.
The gauge body 19 has an elongated plate shape made of metal or resin. The gauge body 19 is inserted into the cylinder of the guide tube 18 from the insertion port 22 of the guide tube 18. The gauge body 19 is provided with a handle 21 at one end in the extending direction. When the gauge body 19 is inserted into the guide tube 18, the handle 21 protrudes from the guide tube 18. The handle 21 has a hanging portion 21a on which a finger can be hung. The handle 21 may be formed by bending a metal plate constituting the gauge body 19, or may be provided in combination with another part made of resin or the like. Further, the gauge body 19 is provided with a measuring unit (not shown) for measuring the oil level at the other end in the extending direction.

The sealing material 20 has a columnar shape and is formed of rubber as an elastic body. The sealing material 20 is integrated with one end side of the gauge body 19 in the extending direction. The handle 21 protrudes from the sealing material 20. The sealing material 20 includes a main body portion 20a on one end side (handle 21 side) along the extending direction of the gauge main body 19 and a sealing portion 20b on the other end side along the extending direction. The extending direction of the central axis of the sealing material 20 is the same as the extending direction of the gauge body 19, and the extending direction of the central axis L1 of the sealing material 20 is the axial direction.

The peripheral length of the main body portion 20a of the sealing material 20 is longer than the peripheral length of the sealing portion 20b. The sealing material 20 has a contact surface 20d at the boundary between the main body portion 20a and the sealing portion 20b in the axial direction.
The sealing portion 20b has an uneven shape along the axial direction. The sealing portion 20b alternately includes a convex portion 20bA extending in the circumferential direction of the sealing portion 20b and a concave portion 20bB having a diameter smaller than that of the convex portion 20bA. The outer diameter of the convex portion 20bA is slightly longer than the inner diameter of the insertion port 22, and the outer peripheral surface of the convex portion 20bA is in close contact with the inner peripheral surface of the insertion port 22.

When the oil level gauge 17 is inserted into the insertion port 22, the contact surface 20d comes into contact with the locking surface 18a, and the oil level gauge 17 cannot be inserted any further. The oil level gauge 17 is designed so that the position where it cannot be inserted is the position where the oil level is measured.

When the gauge body 19 is inserted into the insertion port 22 of the guide tube 18, the outer peripheral surface of the convex portion 20bA of the sealing portion 20b is in close contact with the inner peripheral surface 23 of the insertion port 22, and the insertion port 22 is sealed. Stop.

Further, the sealing material 20 includes a first passage forming portion 30 and a second passage forming portion 31. The first passage forming portion 30 is cut and formed on the outer peripheral surface of the main body portion 20a. The first passage forming portion 30 has a role of a valve that opens and closes by a force acting on the gauge body 19. The first passage forming portion 30 has a shape that is deformed by an external force accompanying the pulling out of the oil level gauge 17 that acts on the sealing material 20. Since the first passage forming portion 30 is formed by a linear notch, it is closed by the elastic force of the elastic body when the external force accompanying the pulling out is not acting.

The cut of the first passage forming portion 30 extends linearly in the circumferential direction of the main body portion 20a. The notch direction of the first passage forming portion 30 is the radial direction of the main body portion 20a. The radial direction of the main body portion 20a is a direction in which a straight line connecting the outer peripheral surface of the main body portion 20a and the central axis L1 of the sealing material 20 extends. In the first passage forming portion 30, one end in the cutting direction is located on the outer peripheral surface of the main body portion 20a, and the other end in the cutting direction is located closer to the outer peripheral surface than the central axis L1 of the sealing material 20.

The first passage forming portion 30 is one end closer to the contact surface 20d in the axial direction of the sealing material 20. Therefore, when the sealing material 20 is inserted into the insertion port 22 and the contact surface 20d is in contact with the locking surface 18a, the first passage forming portion 30 is at a higher position than the locking surface 18a. The first passage forming portion 30 is preferably at a height of 60 mm or more from the locking surface 18a. The locking surface 18a is also a deposit surface on which water and foreign matter are likely to accumulate. By installing the first passage forming portion 30 at a height of 60 mm or more from the locking surface 18a, it becomes easy to suppress the suction of water and foreign matter accumulated on the locking surface 18a.

The second passage forming portion 31 is provided over the main body portion 20a and the sealing portion 20b, and is provided along the axial direction of the sealing material 20. The second passage forming portion 31 is formed by drilling or otherwise drilling a hole in the sealing material 20. One end of the second passage forming portion 31 is connected to the other end of the first passage forming portion 30 in the cutting direction. The other end of the second passage forming portion 31 is open to the tip of the sealing portion 20b. The diameter of the second passage forming portion 31 is large enough to allow ventilation even if the sealing material 20 is deformed by the action of an external force. The diameter of the second passage forming portion 31 is preferably about 5 mm. When the first passage forming portion 30 is open and communicates with the second passage forming portion 31, the opened first passage forming portion 30 and the second passage forming portion 31 communicate with each other as a ventilation path 33 (see FIG. 4B). ) Is formed.

Next, the operation of this embodiment will be described. First, a case where the oil level gauge 17 is not pulled out will be described.
As shown in FIGS. 3A and 3B, since the first passage forming portion 30 is closed, the atmosphere and the oil chamber 16 do not communicate with each other. Therefore, even if the oil chamber 16 has a negative pressure, water and foreign matter are blocked by the first passage forming portion 30 in the closed state. Further, when the oil chamber 16 has a negative pressure, a force generated by the pressure difference between the atmospheric pressure and the inside of the oil chamber 16 acts to close the notch in the first passage forming portion 30 in the direction of closing the first passage forming portion 30. To do. Therefore, the first passage forming portion 30 is closed.

Next, a case where the oil level gauge 17 is pulled out will be described. When the external force F acts by pulling out the oil level gauge 17, the sealing material 20 is deformed in the axial direction by the external force F as shown in FIGS. 4 (a) and 4 (b). As shown in FIG. 4A, the first passage forming portion 30 is deformed into a horizontally elongated elliptical shape and opened. As shown in FIG. 4B, since the opened first passage forming portion 30 communicates with the second passage forming portion 31, a ventilation path 33 in which the atmosphere and the oil chamber 16 communicate with each other is formed. Since the oil chamber 16 is opened to the atmosphere by the ventilation path 33, the negative pressure in the oil chamber 16 is eliminated.

Further, when the external force F accompanying the pulling out of the oil level gauge 17 does not act, the sealing material 20 returns to its original shape due to the elastic force, and the first passage forming portion 30 is closed. Therefore, the atmosphere and the oil chamber are not connected again. Therefore, in the state where the sealing material 20 is not pulled out and the insertion port 22 is sealed, even if the oil chamber 16 becomes negative pressure again, the intrusion of water and foreign matter can be suppressed.

According to the above embodiment, the following effects can be obtained.
(1) The oil level gauge 17 includes a first passage forming portion 30 and a second passage forming portion 31 connected to one end of the first passage forming portion 30 in the sealing material 20. When the external force F due to the pulling out of the oil level gauge 17 does not act on the sealing material 20, the first passage forming portion 30 is closed, and even if the oil chamber 16 has a negative pressure, water or foreign matter to the oil chamber 16 Inhalation can be suppressed. On the other hand, when an external force F accompanying the withdrawal of the oil level gauge 17 acts, the first passage forming portion 30 is deformed by the external force F and communicates with the second passage forming portion 31 to form a ventilation path 33, and the oil is formed. The negative pressure in the chamber 16 can be eliminated. As a result, the oil level gauge 17 can be easily pulled out. Further, even if the entire sealing material 20 of the oil level gauge 17 is not pulled out from the insertion port 22, if an external force F that deforms the sealing material 20 acts, a ventilation path 33 is formed. The negative pressure in the chamber 16 can be released.

(2) When the oil level gauge 17 is installed on the guide tube 18, the first passage forming portion 30 is formed on the sealing material 20 so as to be installed at a position higher than the locking surface 18a of the guide tube 18. ing. As a result, when the first passage forming portion 30 is opened, it is possible to prevent water and foreign matter accumulated on the locking surface 18a from being sucked into the oil chamber 16.

(3) The first passage forming portion 30 is formed so as to extend linearly in the circumferential direction of the sealing material 20. As a result, when the oil level gauge 17 is pulled out, the first passage forming portion 30 is likely to be opened against the external force F acting in the axial direction of the sealing material 20.

(4) The first passage forming portion 30 is a linear notch. As a result, in a state where the external force F does not act on the sealing material 20, the first passage forming portion 30 can be easily closed without a gap.
(5) The second passage forming portion 31 extends linearly without meandering. As a result, not only is it easy to form the second passage forming portion 31 when the sealing material 20 is manufactured, but also the deformation of the second passage forming portion 31 due to the external force F due to the pulling out can be minimized.

(6) The sealing material 20 is made of an elastic body such as rubber. As a result, it is possible to manufacture a deformation characteristic with a simple structure, which is a function of the first passage forming portion 30, that is, it is opened by an external force F accompanying pulling out and closed when the external force F is not acting.

(Second Embodiment)
Next, a second embodiment embodying an oil level gauge for an industrial vehicle will be described with reference to FIG. Since the second embodiment has only a configuration in which the second passage forming portion of the first embodiment is changed, detailed description of the same portion will be omitted.

As shown in FIG. 5, the second passage forming portion 40 has a ventilation groove 41 recessed in the outer peripheral surface of the sealing portion 20b along the axial direction of the sealing material 20 and one end in the extending direction of the ventilation groove 41. It is composed of a continuous passage 42 connecting the first passage forming portion 30 and the other end in the cutting direction of the first passage forming portion 30. The communication passage 42 extends from the central axis L1 side toward the outer peripheral surface along the axial direction of the sealing material 20 so as to connect the other end of the first passage forming portion 30 in the cutting direction and one end of the ventilation groove 41. ing. The diameter of the communication passage 42 is large enough to allow ventilation even if the sealing material 20 is deformed due to the action of an external force due to the pulling out of the oil level gauge 17.

In the second embodiment, the opening of the first passage forming portion 30 by an external force for pulling out the oil level gauge 17 is the same as in the first embodiment. The opened first passage forming portion 30 is connected to the communication passage 42, and a ventilation path is formed by the ventilation groove 41 connected to the communication passage 42. Since the oil chamber 16 is opened to the atmosphere by the ventilation path, the negative pressure of the oil chamber 16 can be eliminated as in the first embodiment.

The above embodiment may be changed as follows.
○ In the embodiment, the oil level gauge 17 is inserted into the guide tube 18 attached to the cylinder block of the engine 6 and the case of the transmission 9, but the present invention is not limited to this. For example, the oil level gauge 17 may be directly inserted into the insertion port 22 formed in the cylinder block of the engine 6 and the case of the transmission 9 instead of the guide tube 18.

○ The oil level gauge 17 may be used not only for measuring the oil level of the engine 6 and the transmission 9 mentioned as the embodiment, but also for measuring the oil level in a reservoir tank of power steering oil, brake oil, or the like.

○ As shown in FIGS. 6 (a) and 6 (b), the first passage forming portion 30 opens at one end in the cutting direction on the outer peripheral surface of the sealing portion 20b when an external force due to pulling out is not applied. However, the shape may be such that the other end in the cutting direction is closed.

○ As shown in FIGS. 7 (a) and 7 (b), the first passage forming portion 30 may have an elliptical cut shape on the outer peripheral surface of the sealing material 20. As a result, the stress concentration on one end side in the cutting direction of the first passage forming portion 30 can be relaxed, so that the growth of cracks at the cutting end can be suppressed and the life of the oil level gauge 17 can be extended.

○ The shape of the sealing material 20 is not limited to a cylindrical shape, and may be, for example, a triangular cylinder shape or a square cylinder shape. As a result, the direction around the axis into which the oil level gauge 17 is inserted into the insertion port 22 can be aligned, and the direction of the first passage forming portion 30 can be set to the direction desired at the time of design.

○ In FIGS. 3 (a), 3 (b), 4 (a), and 4 (b), the second passage forming portion 31 extends linearly along the axial direction of the sealing material 20, but the second passage forming portion 31 extends linearly. If the ventilation path 33 can be formed when the 1 passage forming portion 30 is opened, the shape of the second passage forming portion 31 may be changed. For example, the second passage forming portion 31 may be formed in the axial direction of the sealing material 20. It may be bent along.

○ In the first embodiment, the first passage forming portion 30 has a shape of opening by an external force F acting when the oil level gauge 17 is pulled out, but the first passage forming portion 30 has a shape such as a shearing force accompanying the pulling out. The shape may be opened by a force due to twisting.

○ The industrial vehicle using the present invention is not limited to a forklift, and may be used, for example, in a special vehicle such as an automatic guided vehicle or a fork loader.
The following technical idea (invention) can be grasped from the above-described embodiment.

(1) A liquid level measuring instrument having the structure of the oil level gauge according to claim 1 or 2.
(2) The first passage forming portion is an oil level gauge extending linearly.

(3) The second passage forming portion is an oil level gauge extending linearly.

1 ... Forklift as an industrial vehicle, 16 ... Oil chamber, 17 ... Oil level gauge, 19 ... Gauge body, 20 ... Encapsulant, 20d ... Contact surface, 22 ... Outlet, 30 ... First passage forming part, 31, 40 ... Second passage forming portion.

Claims (1)

The gauge body that is inserted into the oil chamber from the outlet and
The integrally into one end along the extending direction of the gauge body, in a state of being inserted into the insertion port in the oil level gauge industrial vehicle having a sealing member for sealing the insertion opening,
The sealing material is located on one end side of the sealing portion that seals the insertion port and the sealing portion along the extending direction of the gauge body, and is longer than the peripheral length of the sealing portion. Equipped with a main body with a circumference
In a state where the sealing material is inserted into the insertion port, the sealing portion is in close contact with the inner peripheral surface of the insertion port, and the contact surface serving as a boundary between the sealing portion and the main body portion is formed. It comes into contact with the periphery of the insertion port and
In the sealing material, a first passage forming portion formed by cutting into the outer peripheral surface of the main body portion , and a second passage forming portion in which one end is connected to the first passage forming portion and the other end communicates with the oil chamber. And are provided,
The first passage forming portion is closed when the external force accompanying the pulling out of the gauge body from the insertion port does not act, and opens when the external force acts to form the first passage. An oil level gauge characterized in that the atmosphere and the oil chamber communicate with each other through a portion and the second passage forming portion.