JP2013205050A - Oil level gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent oil from being leaked from the inside of a casing of a transmission or the like and a foreign substance such as water or dust from being mixed into the casing with a simple configuration where the number of components and processing steps are suppressed in an oil level gauge comprising a breather function.SOLUTION: An oil level gauge comprises a seal member (20) fixed between a gauge rod (11) and a gauge plate (15) and having elasticity, and a plurality of projected step parts (26a-26d) formed side by side along an axial direction on an outer peripheral surface of the seal member (20). The oil level gauge further comprises a plurality of groove parts (28a-28d) formed by recessing a part of each of the plurality of step parts (26a-26d) in a circumferential direction along the axial direction, and while the seal member (20) is attached to an insertion port (5), a labyrinth-like ventilation path (30) is defined by gaps (27a-27c) provided among the plurality of step parts (26a-26d) and the groove parts (28a-28d).

Description

  The present invention relates to an oil level gauge for measuring the level of oil contained in a casing or an engine block of a transmission mounted on a vehicle.

  Conventionally, there is an oil level gauge as shown in Patent Document 1, for example. This type of oil level gauge measures the level of oil accumulated in the casing or engine block of a transmission mounted on a vehicle. In addition to the level of oil, it adheres to the oil level gauge. It is also possible to detect the deterioration state of the oil based on the color of the oil.

  On the other hand, as a breather mechanism for suppressing atmospheric pressure fluctuation in the casing by discharging gas inside the casing of the transmission to the outside, for example, as shown in Patent Document 2, it is installed in the casing of the transmission. There is a breather mechanism including a breather pipe and a rubber cap attached to the opening of the breather pipe.

  When the breather mechanism described in Patent Document 2 is provided in a transmission or the like, an oil level gauge having the above-described configuration is required separately from the breather mechanism. As described above, if the breather mechanism and the oil level gauge are separately provided, the number of parts constituting the transmission is increased and the structure becomes complicated. Further, the rubber cap of the breather mechanism requires a dedicated press-fitting work process for press-fitting the cap. Therefore, it takes time and effort to assemble the transmission including the breather mechanism, and there is a problem in improving the efficiency of the transmission manufacturing process.

  On the other hand, in the oil level gauge (liquid level detection device) described in Patent Document 3, by forming a groove for the air passage in the plug member of the oil level gauge that closes the opening of the gauge pipe (tubular member), The oil level gauge has a breather function. According to this configuration, since a separate breather mechanism can be omitted, the number of parts of the transmission can be reduced and the configuration can be simplified.

Japanese Patent No. 412549 JP-A-9-310773 JP 2001-296169 A

  However, in the prior art described in Patent Document 3, the vent hole groove provided in the plug member of the oil level gauge is a straight groove extending in the axial direction of the gauge pipe. Therefore, when the oil level in the casing rises and enters the gauge pipe, the oil that has entered the gauge pipe may reach the plug member and leak out from the vent hole. In addition, foreign matters such as moisture and dust may enter from the outside of the casing through the vent holes.

  In this regard, in the prior art described in Patent Document 3, when the oil level in the casing rises, in order to prevent the oil from reaching the plug member of the oil level gauge, The shielding part which reduces the pipe cross-sectional area in a gauge pipe rather than another part is provided. However, the above-mentioned shielding part is formed so that a part of the gauge pipe is reduced in diameter, or has a structure in which a member separate from the plug member is provided in the oil level gauge. This is accompanied by an increase in processing steps, an increase in the number of parts, and a complicated structure.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a casing for a transmission or the like in an oil level gauge having a breather function, while having a simple configuration with a reduced number of parts and processing steps. An object of the present invention is to provide an oil level gauge capable of effectively preventing leakage of oil from the inside and entry of foreign matters such as water and dust into the casing.

  The present invention for solving the above problems is an oil level gauge (10) for measuring the liquid level height of the oil (8) accommodated in the casing (2), one end of which is the casing (2). ) And a cylindrical gauge pipe (3) having an insertion port (5) at the other end, and an elastic seal member (20) to be attached to the insertion port (5) of the gauge pipe (3). And a gauge rod (11) having a handle portion (12) fixed to one end of the seal member (20), and a gauge having a measuring portion (16) fixed to the other end of the seal member (20). Plate (15), and a projecting step portion (26a to 26d) extending in the circumferential direction on the outer peripheral surface of the plug portion (25) to be inserted into the insertion port (5) of the seal member (20). ) Along the axial direction of the gauge pipe (3) A plurality of the plurality of step portions (26a to 26d) are formed side by side, and each of the plurality of step portions (26a to 26d) includes a plurality of groove portions (28a to 28d) that are recessed along the axial direction. 5) In the state where the seal member (20) is mounted, the gauge (27a-27c) and the groove (28a-28d) provided between the plurality of stepped portions (26a-26d) A maze-like air passage (30) communicating from the inside of the pipe (3) to the outside is formed.

  According to the oil level gauge of the present invention, an air passage communicating from the inside of the gauge pipe to the outside is formed on the outer peripheral surface of the seal member in a state where the seal member of the oil level gauge is inserted into the insertion port of the gauge pipe. The Therefore, the breather function for ventilating the casing in the oil level gauge can be provided by the vent passage. In addition, since the air passage is a labyrinth air passage defined by a gap provided between the step portions of the seal member and a groove portion formed in the step portion, the oil in the casing is formed via the air passage. The breather structure is less likely to leak to the outside and less likely to be mixed with foreign matters such as water and dust from the outside of the casing. And in said oil level gauge, said labyrinth-shaped ventilation path is provided with the simple structure which forms only the groove part which hollowed some of the several step parts provided in the plug part of the sealing member. . Therefore, according to the oil level gauge according to the present invention, the number of parts is the same as that of the conventional oil level gauge, and it is a very simple configuration in which the above groove is newly added. The oil level gauge can effectively prevent leakage of oil and contamination of foreign matter such as water and dust into the casing.

  Further, in the oil level gauge, the plurality of groove portions (28a to 28d) face each other of the plug portions (25) when viewed from the axial direction with respect to each of the plurality of step portions (26a to 26d). It is good to form alternately on both sides. According to this configuration, the ventilation path defined by the gaps provided between the plurality of step portions is a path that alternately connects the opposite sides of the plug portion, thereby increasing the path length of the ventilation path. It becomes possible to secure as. Therefore, it is possible to more effectively prevent oil leakage from the casing and entry of foreign matters such as water and dust into the casing.

In the oil level gauge, a guide portion (31) formed in a tapered shape may be provided at an end portion on the gauge plate (15) side of the seal member (20). According to this structure, the guide part formed in the taper taper shape becomes easy to align when the seal member of the oil level gauge is assembled to the insertion port of the gauge pipe. Therefore, the operation of installing the oil level gauge in the gauge pipe can be performed efficiently. Thereby, in the measurement of the oil level using the oil level gauge, it becomes easy to return the oil level gauge into the gauge pipe.
In addition, the code | symbol in said parenthesis shows the code | symbol of the component in embodiment mentioned later as an example of this invention.

  According to the present invention, in an oil level gauge having a breather function, oil leakage from a case such as a transmission, water in the case, It is possible to effectively prevent foreign substances such as dust from entering.

It is a figure showing some transmissions provided with the oil level gauge concerning one embodiment of the present invention. It is a perspective view which shows the sealing member of an oil level gauge, (a) is the figure seen from one side surface side, (b) is the figure seen from the other side surface side. It is side sectional drawing which shows the sealing member of the oil level gauge with which the insertion port of the gauge pipe was mounted | worn. It is a figure which shows the flow of the air which passes the outer periphery of a sealing member. It is a figure for demonstrating the procedure which attaches a sealing member to the insertion port of a gauge pipe, (a) is a top view of a sealing member and a gauge pipe, (b) is a side view (partly) of a sealing member and a gauge pipe FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a view showing a part of a transmission including an oil level gauge according to an embodiment of the present invention. An oil level gauge 10 shown in FIG. 1 includes a gauge rod 11 made of a round bar, a seal member 20 fixed to the lower end of the gauge rod 11, and a gauge plate 15 extending downward from the lower end of the seal member 20. Yes. A substantially annular handle portion 12 is formed at the upper end of the gauge rod 11. The gauge plate 15 is a thin plate-like strip having flexibility made of metal, and a flat plate-like measurement unit 16 is provided at the lower end thereof. The seal member 20 is an elastic part integrally formed of a rubber material such as acrylic rubber, and is fixed between the lower end of the gauge rod 11 and the upper end of the gauge plate 15, and the gauge rod 11 and the gauge plate. 15 are integrally connected.

  The oil level gauge 10 is attached to a gauge pipe 3 provided in the casing 2 of the transmission 1. The gauge pipe 3 is a cylindrical member made of metal or synthetic resin. The gauge pipe 3 extends at a side portion of the casing 2 of the transmission 1 while appropriately bending downward from an insertion port 5 at the upper end, and a lower end portion 6. Is attached near the bottom of the casing 2. Therefore, the gauge pipe 3 communicates the inside and outside of the casing 2. The lower end portion 6 of the gauge pipe 3 opens toward the oil surface 9 of the oil 8 accumulated in the casing 2.

  2A and 2B are perspective views showing the seal member 20 of the oil level gauge 10, wherein FIG. 2A is a view seen from one side face, and FIG. 2B is a view seen from the other side face. 3A is a side sectional view showing the sealing member 20 attached to the insertion port 5 of the gauge pipe 3, FIG. 3B is an enlarged view of a portion X of FIG. 3A, and FIG. FIG. As shown in these drawings, the seal member 20 of the oil level gauge 10 includes a substantially disc-like cover plate 21 provided at the upper end and a plurality of step portions 26 (26a to 26a provided on the lower side of the cover plate 21. 26d) and a guide portion 31 formed in a tapered shape provided at the lower end of the plug portion 25 are integrally provided. The cover plate 21 has a substantially circular flat plate shape whose outer diameter is formed to be larger than the diameter of the insertion port 5 of the gauge pipe 3. A notch 21c is provided. The notch 21c is a U-shaped recess, and is a portion with which the guide piece 4 (see FIG. 3) installed on the outer periphery of the insertion port 5 of the gauge pipe 3 is engaged.

  The plug portion 25 provided on the lower surface 21 a side of the lid plate 21 is a substantially cylindrical portion having a smaller diameter than the lid plate 21, and is inserted into the insertion port 5 when the seal member 20 is attached to the gauge pipe 3. Part. On the outer peripheral surface of the plug portion 25, a plurality of annular projecting step portions 26 extending in the circumferential direction are formed side by side along the axial direction of the gauge pipe 3. In the present embodiment, four (four) step portions 26a to 26d are formed. In addition, a plurality of groove portions 28 (28a to 28d) are provided in which a part of each of the plurality of step portions 26a to 26d is recessed substantially linearly along the axial direction. The plurality of groove portions 28a to 28d formed in the plurality of step portions 26a to 26d are alternately formed on opposite sides of the plug portion 25 when viewed from the axial direction of the seal member 20. That is, when the front surface shown in FIG. 2A of the seal member 20 is one surface and the front surface shown in FIG. 2B is the other surface, the seal member 20 is formed on the lowermost step 26a. The groove portion 28a faces one surface, and the groove portion 28b formed on the step portion 26b above the groove portion 28a faces the other surface. The groove portion 28c formed on the step portion 26c above the groove portion 28c faces one surface. The groove portion 28d formed in the step portion 26d on the upper side faces the other surface.

  Grooves 28 (28 e) are also formed on the lower surface 21 a of the cover plate 21. The groove portion 28e communicates with a groove portion 28d formed in the uppermost step portion 26d, and extends from the groove portion 28d to the outer peripheral end 21b of the lid plate 21 in the radial direction on the lower surface 21a of the lid plate 21. .

  The outer diameter of the step portion 26 (26a to 26d) is set to be slightly larger than the diameter of the insertion port 5 of the gauge pipe 3 and the inner peripheral surface 3a in the vicinity thereof (see FIG. 3). On the other hand, the outer diameter of the gap 27 (27a-27c) provided between the adjacent step portions 26 (26a-26d) is set to a slightly smaller diameter than the diameter of the inner peripheral surface 3a. Yes. Thus, with the plug portion 25 of the seal member 20 inserted into the insertion port 5 of the gauge pipe 3, the tips (radially outer peripheral ends) of the step portions 26 are inside the gauge pipe 3 as shown in FIG. 3. A minute space is formed between the gap 27 (27a to 27c) provided between the adjacent step portions 26 (26a to 26d) and the inner peripheral surface 3a of the gauge pipe 3 by being press-fitted into the peripheral surface 3a and closely contacting each other. Is done. In this state, a minute space is also formed between each groove 28 (28a to 28d) and the inner peripheral surface 3a of the gauge pipe 3. A minute space is also formed between the groove 28 e on the lower surface 21 a of the cover plate 21 and the opening end (upper end) of the insertion port 5. As a result, as shown in FIG. 3, the gap 27 (27a-27c) and the groove 28 (28a-28e) provided between the step portions 26 (26a-26d) of the seal member 20 An air passage 30 communicating from the outside to the outside is formed. As will be described later, the ventilation path 30 is a so-called labyrinth path that advances while alternately bending in the circumferential direction and the axial direction along the outer peripheral surface of the seal member 20 (plug portion 25).

  The guide portion 31 provided below the stopper portion 25 has an inverted conical outer shape that gradually decreases in diameter toward a lower end portion (lower end surface) 31a to which the gauge plate 15 is fixed. The diameter of the lower end portion 31a of the guide portion 31 is set to be significantly smaller than the diameter of the plug portion 25 (for example, about 1/4 or less).

  As shown in FIG. 1, the oil level gauge 10 having the above configuration places the gauge plate 15 in the gauge pipe 3 by attaching the seal member 20 to the insertion port 5 of the gauge pipe 3. In this state, the measurement unit 16 at the lower end of the gauge plate 15 is immersed in the oil 8 accumulated at the bottom of the casing 2.

  In order to measure the liquid level height of the oil 8 in the casing 2, first, the oil level gauge 10 is pulled out from the gauge pipe 3, and the oil adhering to the measuring portion 16 of the oil level gauge 10 and the vicinity thereof is wiped off. Thereafter, the measuring member 16 of the oil level gauge 10 is immersed in the oil 8 by attaching the seal member 20 to the insertion port 5 of the gauge pipe 3 again. Thereafter, the oil level gauge 10 is pulled out, and the oil level in the casing 2 is measured by visually observing the oil adhering to the measuring unit 16. In normal times other than when this measurement is performed, the seal member 20 is attached to the insertion port 5 of the gauge pipe 3 and the oil level gauge 10 is attached to the gauge pipe 3. In this state, the insertion port 5 of the gauge pipe 3 is blocked by the plug portion 25 of the seal member 20.

  In the oil level gauge 10 according to the present embodiment, as described above, the gauge pipe 3 is provided on the outer periphery of the seal member 20 (plug portion 25) in a state where the seal member 20 is attached to the insertion port 5 of the gauge pipe 3. An air passage 30 communicating from the inside to the outside is formed. Therefore, a breather function for ventilating the casing 2 is provided by the vent passage 30. Hereinafter, the breather function by the ventilation path 30 will be described.

  While the vehicle is traveling, the pressure in the casing 2 fluctuates due to a temperature change in the casing 2 of the transmission 1. At this time, when the pressure in the casing 2 rises, the gas (air) in the casing 2 is discharged to the outside through the air passage 30 of the oil level gauge 10. 4A and 4B are views showing the flow of air passing through the outer periphery of the seal member 20 at that time, wherein FIGS. 4A to 4G are side views of the seal member 20, and FIG. 4H is a bottom view of the seal member 20. FIG. It is. In the figure, the gauge pipe 3 to which the seal member 20 is attached is not shown, but in the implementation, the inner peripheral surface 3a of the gauge pipe 3 and the outer peripheral surface of the plug portion 25 of the seal member 20 Air flows between them.

  In this case, the air that has reached the seal member 20 from the casing 2 through the gauge pipe 3 is formed in the lowermost step portion 26a on one side surface of the seal member 20, as shown in FIG. It flows from the groove portion 28a into the upper gap 27a of the step portion 26a. Then, as shown in FIG. 4 (b), it flows in the circumferential direction of the sealing member 20 through the gap 27a, and as shown in FIG. 4 (c), the second step from the bottom on the other side surface of the sealing member 20 The groove 28b formed in the portion 26b flows into the gap 27b on the upper side of the step portion 26b. Thereafter, as shown in FIG. 4 (d), it flows through the gap 27b in the circumferential direction of the seal member 20, and as shown in FIG. 4 (e), on the one side surface of the seal member 20, the third from the bottom. It flows into the upper gap 27c from the groove 28c formed in the stepped portion 26c. Thereafter, as shown in FIG. 4 (f), it flows in the circumferential direction of the seal member 20 through the gap 27c, and as shown in FIG. 4 (g), on the other side of the seal member 20, the fourth from the bottom. It flows out from the groove part 28d formed in the step part 26d, and flows out from the insertion port 5 of the gauge pipe 3 through the groove part 28e formed in the lower surface 21a of the cover board 21, as shown in FIG.4 (h).

  In addition, when the pressure in the casing 2 falls, external air is introduced into the casing 2 through the air passage 30 of the oil level gauge 10. In this case, the air flow in the air passage 30 is in the opposite direction to that in FIG. 4 and the above description, and the air flowing in from the groove 28e formed in the lower surface 21a of the cover plate 21 is directed in the air passage 30 in the reverse direction. And is introduced into the gauge pipe 3 through a groove 28a provided in the lowermost step 26a.

  As described above, the air passage 30 provided in the oil level gauge 10 of the present embodiment is formed in the gaps 27a to 27c and the step portions 26a to 26d provided between the plurality of step portions 26a to 26d in the seal member 20. This is a so-called labyrinth-shaped passage defined by the grooves 28a to 28e. Therefore, the breather structure is less likely to cause the oil in the casing 2 to leak to the outside through the air passage 30 and less likely to contaminate foreign matters such as water and dust from the outside of the casing 2. The vent passage 30 has a simple configuration in which grooves 27a to 27d are formed by recessing a part of the plurality of step portions 26a to 26d provided in the seal member 20. Therefore, according to the oil level gauge 10, the number of parts is the same as that of the conventional oil level gauge 10, and the casing 27 has a very simple configuration in which the groove portions 27 a to 27 d are newly added. The oil level gauge 10 can effectively prevent the leakage of oil from the inside 2 and the entry of foreign matter such as water and dust into the casing 2.

  Further, in the oil level gauge 10, the plurality of groove portions 28a to 28d are alternately formed on the opposite sides of the plug portion 25 when viewed from the axial direction of the seal member 20 with respect to each of the plurality of step portions 26a to 26d. Has been. Thereby, the ventilation path 30 defined by the gaps 27a to 27c and the groove portions 28a to 28e is a path that alternately connects the opposite sides of the plug portion 25 to each other. By adopting such a configuration, a relatively long path is secured as the path length of the ventilation path 30. Therefore, leakage of oil from the casing 2 and entry of foreign matters such as water and dust into the casing 2 can be more effectively prevented.

  5A and 5B are diagrams for explaining a procedure for mounting the seal member 20 to the insertion port 5 of the gauge pipe 3, wherein FIG. 5A is a plan view of the seal member 20 and the gauge pipe 3, and FIG. 5B is a seal member. 20 is a side view (partial cross-sectional view) of the gauge pipe 3 and FIG. As shown in the figure, in the case of a layout in which the gauge pipe 3 is bent, a thin plate-like gauge plate 15 is arranged in the gauge pipe 3 in a state bent against its elasticity. Therefore, if the degree of bending of the gauge pipe 3 is large, the gauge plate 15 is elastically stretched when the seal member 20 is attached to the insertion port 5 of the gauge pipe 3. Will be greatly eccentric. Therefore, it is necessary to position the seal member 20 with respect to the insertion port 5 (centering) by moving the seal member 20 against the elasticity of the gauge plate 15 and then mount the seal member 20 on the insertion port 5.

  On the other hand, in the oil level gauge 10 of the present embodiment, a guide portion 31 formed in a tapered shape is provided at the lower end of the seal member 20. By providing the guide portion 31, the lower end of the seal member 20 (the lower end portion 31 a of the guide portion 31) is significantly reduced in diameter compared to the outer diameter of the plug portion 25. Thereby, the movement amount when aligning the seal member 20 with respect to the insertion port 5 can be reduced. That is, as shown in FIG. 5A, as viewed from the upper side of the seal member 20, the seal is as much as the lower end portion 31 a of the seal member 20 indicated by the symbol A enters the insertion port 5 of the gauge pipe 3 indicated by the symbol B. The member 20 may be moved. Thereby, the operation | work which attaches the sealing member 20 of the oil level gauge 10 to the insertion port 5 of the gauge pipe 3 can be performed easily. Therefore, the oil level gauge 10 can be easily and quickly returned to the gauge pipe 3 after the oil level is measured by the oil level gauge 10.

  Further, the tapered guide portion 31 is provided as a separate portion from the plug portion 25 below the plug portion 25. Therefore, the sealing member 20 does not change the load when the plug portion 25 of the sealing member 20 is inserted into or removed from the insertion port 5 of the gauge pipe 3, and the stability against misalignment during mounting is not impaired. The mounting property of the seal member 20 is improved by suppressing the amount of movement required for the alignment of 20 to a small amount.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Deformation is possible. For example, the specific shapes and numbers of the step portion 26, the gap 27, and the groove portion 28 included in the seal member 20 shown in the above embodiment are only examples, and the step portion, the gap, and the groove portion included in the seal member according to the present invention are The shape, number, and arrangement other than those shown in the above embodiments may be used.

DESCRIPTION OF SYMBOLS 1 Transmission 2 Casing 3 Gauge pipe 3a Inner peripheral surface 5 Insertion port 8 Oil 9 Oil surface 10 Oil level gauge 11 Gauge rod 12 Handle part 15 Gauge plate 16 Measuring part 20 Sealing member 21 Cover plate 21a Lower surface 21b Outer end 25 Plug part 26 (26a to 26d) Step portion 27 (27a to 27c) Gap 28 (28a to 28e) Groove portion 30 Air passage 31 Guide portion 31a Lower end portion

Claims (3)

An oil level gauge for measuring the level of oil contained in the casing,
A cylindrical gauge pipe having one end opened in the casing and the other end having an insertion port;
An elastic seal member attached to the insertion port of the gauge pipe;
A gauge rod having a handle fixed to one end of the seal member;
The gauge plate having a measurement part fixed to the other end of the seal member,
A plurality of protruding step portions extending in the circumferential direction are formed side by side along the axial direction of the gauge pipe on the outer peripheral surface of the plug portion inserted into the insertion port in the seal member,
A plurality of groove portions formed by recessing a part of each of the plurality of step portions in the circumferential direction along the axial direction;
A maze-like air passage communicating from the inside of the gauge pipe to the outside is formed by the gap and the groove provided between the plurality of step portions in a state where the seal member is attached to the insertion port. Oil level gauge characterized by that. 2. The oil level gauge according to claim 1, wherein the plurality of groove portions are alternately formed on opposite sides of the plug portion when viewed from the axial direction with respect to each of the plurality of step portions. . 3. The oil level gauge according to claim 1, wherein a guide portion formed in a tapered shape is provided at an end of the seal member on the gauge plate side. 4.

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