JP3749791B2 - Oil level gauge and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil level gauge that checks the amount of oil in an oil tank of a vehicle engine or the like, and relates to an oil level gauge in which a resin-made grip member is provided at the rear end of the gauge member and a method for manufacturing the same. .
[0002]
[Prior art]
Generally, devices such as engines and transmissions have an oil tank, and oil such as lubricating oil is held in the oil tank. In this type of device, oil in the oil tank is used by using an oil level gauge. A method of checking the amount of dirt and the degree of contamination is widely adopted.
[0003]
For example, in the case of an engine, as shown in FIG. 7, an oil level gauge 30 is inserted through a guide tube 10 from a mounting opening 1 a opened on the side of the engine 1, and the oil in the oil tank 2 is The gauge member 4 is immersed in 2a, and the oil level gauge 3 is pulled out as necessary to inspect the amount of oil and the degree of dirt from the state of oil attached to the gauge member 4.
[0004]
As shown in FIG. 5, the oil level gauge 30 includes a grip member 8 and a gauge member 4 with marks H and L for detecting the amount of oil. The gauge member 4 is formed of a metal thin plate material such as spring steel, and the grip member 8 is often formed of a synthetic resin material, and these are integrated. The grip member 8 includes an attachment portion 5 for fixing to the attachment port 1a and a grip portion 6 for holding by hand.
[0005]
Methods for integrating the grip member 8 and the gauge member 4 include an insert molding method and an electromagnetic induction heating welding method proposed in Japanese Patent Laid-Open No. 7-248244.
In this insert molding method, as shown in FIG. 8, the fixing portion 4 b of the metal gauge member 4 is held in a cantilever state in the space portion 64 of the dies 61 and 62, and this is injected from the inlet 63. The grip member 8 integrated with the gauge member 4 is formed by supplying molten resin to the space portion 64.
[0006]
In the electromagnetic induction heating welding method, as shown in FIG. 9, the resin grip member 8 and the metal gauge member 4 are separately molded, and the fixing portion 4 b of the gauge member 4 is attached to the grip member 8. This coupling portion is inserted into the insertion hole, this coupling portion is set in the electromagnetic coil 66, a high-frequency current is passed from the high-frequency power source 67 to the coil 66, and heat is generated by electromagnetic induction in the metal portion 4b in the coil 66. The surrounding resin is welded and integrated by heat generated in the portion 4b.
[0007]
On the other hand, for the airtight maintenance between the oil level gauge 30 and the guide tube 10 into which the oil level gauge 30 is inserted, the O-ring 7 is widely used when the mounting portion 5 is formed of a resin material. That is, an O-ring seal groove 5a for the O-ring 7 is provided in the mounting portion 5, and airtightness is maintained by the seal of this portion to prevent leakage of blow-by gas in the crankcase of the engine 1 into the atmosphere. Yes.
[0008]
[Problems to be solved by the invention]
However, in both of the insert molding method and the electromagnetic induction heating welding method, the O-ring seal groove 5a is formed at the same time as the resin grip member 8 is molded, but the gauge member 4 and the grip member 8 Since the resin part and metal part become hot when the O-ring is integrated and the O-ring seal groove 5a is also affected by heat, the O-ring 7 is attached to the grip after completion of the molding process and welding process to avoid this heat effect. It is necessary to carry out after the member 8 and the gauge member 4 are sufficiently cooled. Therefore, since the cooling time of these members is required, there is a problem that the cycle time of the work increases and the productivity is lowered.
[0009]
In addition, the grip portion 6 which is a part of the grip member 8 is formed larger than the inner diameter of the O-ring 7 so that it can be easily held by hand in consideration of the workability at the time of checking the oil. 6 cannot be performed from the gripping portion 6 side, and therefore, as shown in FIG. 6, it is inserted from the distal end portion 4a side of the gauge member 4, but the workability is poor because the gauge member 4 is long. Further, productivity is reduced.
[0010]
Moreover, since the gauge member 4 is made of metal and often has edges, burrs, and the like, the O-ring 7 formed of an elastic material passes through the long metal member 4 and is attached to the O-ring seal groove 5a. Until it is done, it is often damaged by its edges, burrs, etc., and there is a problem that the longer the gauge member 4 is, the more easily the O-ring 7 is damaged.
[0011]
On the other hand, there is an ultrasonic welding method that is used in a wide range of AV equipment, fibers, electronic parts, and the like, and is greatly contributing to labor saving and productivity. In this method, a horn that transmits vibration energy generated by an ultrasonic transducer is pressed against the contact surface between the resins, and the frictional energy is transmitted and pressurized to cause local friction at the resin boundary surface that is the contact surface. This method generates heat and instantly welds the contact surface.
[0012]
When this ultrasonic welding method is adopted, heat is generated locally only at the interface of the resin to be welded, so the high temperature part is limited and the cooling is fast, and there is no need to provide a cooling time, greatly increasing the cycle time. Can be shortened. Moreover, since the reproducibility of the processing conditions is good, it is possible to always provide products with stable quality. In addition, it can usually be welded in about 1 second instantly, and pre-processing and post-processing are not required, so it is effective for introduction into an automated line and can improve productivity, resulting in lower costs. There are benefits.
[0013]
The present invention has been made in order to solve the above-described problems, and the object of the present invention is to employ an ultrasonic welding method to form a metal gauge member and a resin grip member of an oil level gauge. Oil level gauge that can prevent the O-ring from being damaged by the gauge member and improve the workability when the O-ring is installed by attaching the O-ring to the oil level gauge mounting part in advance. It is in providing the manufacturing method.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, an oil level gauge according to the present invention is provided with an O-ring seal groove for an O-ring around a cylindrical mounting portion of a synthetic resin grip member, and at the tip of the O-ring seal groove. A fitting hole for inserting and fixing the fixing portion of the gauge member is opened in the axial direction of the mounting portion on the side, and the mounting portion is divided along the fitting hole on the tip side of the O-ring seal groove. Formed with a lid body and a receiver, and with the fixing portion inserted into the fitting hole, the lid body and the receiver are sandwiched and assembled, and the lid body and the receiver This method is characterized by ultrasonic welding of the mating surfaces.
[0015]
And this oil level gauge manufacturing method is such that after the O-ring is mounted in the O-ring seal groove of the mounting portion or in the vicinity of the O-ring seal groove, the fixing portion is fitted into the fitting hole. The fixing part is sandwiched and assembled between the lid and the receiver, and a joint surface between the lid and the receiver is ultrasonically welded.
According to the above configuration and manufacturing method, since the ultrasonic welding method is adopted, the welding of the mounting portion molded in a pre-divided state is usually instantaneous for about 1 second due to local heat generation at the mating surface portion. In between, the temperature hardly rises in the O-ring seal groove of the mounting portion.
[0016]
Further, since the O-ring seal groove is formed on the grip portion side from the divided portion of the mounting portion, the O-ring can be mounted in advance without disturbing the assembly of the gauge member and the mounting portion.
Therefore, the O-ring can be mounted from the tip of the mounting portion before the gauge member and the grip member are assembled, and it is not necessary to pass the long gauge member through the O-ring. The travel distance is significantly shortened. At the same time, damage due to the edges and burrs of the gauge member is avoided.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, an oil level gauge 3 according to the present invention includes a long plate-like gauge member 4 for checking the amount of oil in the oil tank 2 and the degree of dirt, and a cylindrical mounting portion. 5 and a grip member 8 comprising a grip portion 6 having a ring for gripping by hand.
[0018]
An upper limit mark H indicating the upper limit position of the oil amount in the oil tank 2 and a lower limit mark L indicating the lower limit position are provided at predetermined positions of the tip end portion 4 a of the gauge member 4.
Further, as shown in FIG. 7, the attachment portion 5 of the grip member 8 has an attachment port which is an inlet of the guide tube 10 when the oil level gauge 3 is inserted into the attachment port 1 a of the oil tank 2 of the engine 1 or the like. A stopper portion 5b serving as a reference for the distance between the upper and lower limit marks H and L is fixed to the gripping portion 6 of the mounting portion 5 so as to be in contact with la and limit the insertion amount of the oil level gauge to always be the same insertion amount. The side is provided with a large diameter.
[0019]
An O-ring seal groove 5a for the O-ring 7 is provided around the cylindrical mounting portion 5 on the distal end side of the stopper portion 5b. When the O-ring 7 is attached to the O-ring seal groove 5a and the oil level gauge 3 is inserted into the guide tube 10, the inner peripheral surface of the guide tube 10 abuts and presses against the O-ring 7 to maintain airtightness. Therefore, the blow-by gas of the engine 1 can be prevented from leaking outside.
[0020]
Further, a fitting hole 13 for inserting and fixing the fixing portion 4b of the gauge member 4 is opened in the axial direction of the mounting portion 5 on the tip side from the O-ring seal groove 5a of the mounting portion 5, and this fitting hole is preliminarily opened. A mounting portion 5 is formed by the lid body 8b and the receiving body 8a formed by resin in a state of being divided along the front end side of the O-ring seal groove 5a along the line 13.
That is, the division position D in the gauge longitudinal direction of the lid 8b and the receiver 8a is provided on the gage member 4 side from the O-ring seal groove 5a, that is, on the side where the upper limit mark H of the gauge is provided. By this division, the O-ring seal groove 5a is disposed only on the receiver 8a side.
[0021]
Then, with the fixing portion 4b inserted into the fitting hole 13, the lid 8b and the receiver 8a are sandwiched and assembled, and the joint surface 8c of the lid 8b and the receiver 8a is ultrasonically welded. An oil level gauge 3 is formed.
Next, a method for manufacturing the oil level gauge 3 will be described.
First, after the O-ring 7 is mounted in the O-ring seal groove 5a of the receiver 8a of the attachment portion 5, the O-ring 7 is mounted in the O-ring seal groove 5a of the receiver 8a of the grip member 8.
[0022]
The O-ring 7 is preferably mounted in the O-ring seal groove 5a in order to reduce the number of labors. However, the O-ring seal groove 5a is close to the dividing surface D due to the arrangement, and is welded. If the O-ring 7 is likely to be affected by heat, as shown in FIG. 2, the O-ring seal groove 5a is closer to the gripping portion 6 side, that is, near the rear end side of the O-ring seal groove 5a. You may attach to the part which is not influenced by heat. If there is no possibility of being affected by heat, it may be mounted in the vicinity of the front end side of the O-ring seal groove 5a and then mounted again in the O-ring seal groove 5a.
[0023]
After the O-ring 7 is mounted, the fixing portion 4b is sandwiched between the lid 8b and the receiver 8a in a state where the fixing portion 4b of the gauge body 4 is inserted into the fitting hole 13 of the receiver 8a. The assembly of the gauge member 4, the receiver 8a, and the lid 8b is completed.
Next, a megaphone cone 60 that transmits the vibration energy of the ultrasonic vibrator is brought into contact with the grip member 8 sandwiching the gauge member 4 as shown in FIG. Vibration energy is generated, and by this vibration energy and pressurization, frictional heat is generated on the joint surface 8c between the receiver 8a and the lid body 8b, and the ultrasonic vibration energy is stopped after melting the resin on both sides. And let it cool and fix. This welding is usually performed locally within about 1 second, and the receiver 8a and the lid 8b are welded, and the oil level gauge 3 in which the gauge member 4 and the grip member 8 are integrated is provided. It ’s done.
[0024]
When the O-ring 7 is mounted in the vicinity of the O-ring seal groove 5a, the oil level gauge 3 is completed by mounting the O-ring 7 again in the O-ring seal groove 5a after the O-ring seal groove 5a is cooled. .
According to the above oil level gauge and its manufacturing method, since the ultrasonic welding method is adopted, the welding of the divided mounting portion 5 is usually performed for an instant of about 1 second due to local heat generation at the joint surface 5c portion. Therefore, since the temperature hardly increases in the O-ring seal groove 5a of the mounting portion 5, even if the O-ring 7 is mounted before the welding process, it is not affected by heat.
[0025]
Moreover, since the O-ring seal groove 5a is formed on the gripping part 6 side from the division position D of the attachment part 5, even if the O-ring 7 is attached in advance, it does not interfere with the assembly of the gauge member 4 and the attachment part 5. .
Accordingly, before the gauge member 4 and the grip member 8 are assembled, the O-ring 7 can be mounted in the O-ring seal groove 5a of the mounting portion 5 of the grip member 8 or in the vicinity thereof. There is no need to allow the gauge member 4 to be passed through. For this reason, since the moving distance when the O-ring 7 is mounted is remarkably shortened, workability at the time of mounting is improved.
[0026]
Further, since the passage of the edges and burrs of the metal gauge member 4 can be avoided when the O-ring 7 is mounted, damage to the O-ring 7 due to these edges and burrs can be prevented, and the sealing performance can be improved.
In addition, an O-ring seal groove 5a, which is important for airtightness maintenance, is formed between the oil level gauge 3 and the guide tube 10 when the grip member 8 is molded. After the molding, the O-ring seal groove 5a is subjected to thermal deformation due to high heat. Therefore, since the dimensional accuracy of the O-ring seal groove 5a can be increased, the airtight holding ability can be improved.
[0027]
【The invention's effect】
According to the oil level gauge and the manufacturing method thereof of the present invention, since the ultrasonic welding method is adopted, the welding of the mounting portion resin-molded in a previously divided state is usually 1 due to local heat generation at the mating surface portion. Since it is performed in the moment before and after the second, the temperature hardly increases in the O-ring seal groove of the mounting portion, so that even if the O-ring is mounted before the welding process, it is not affected by heat.
[0028]
In addition, since the O-ring seal groove is formed on the gripping portion side from the divided portion of the attachment portion, even if the O-ring is attached in advance, it does not interfere with the assembly of the gauge member and the attachment portion.
Therefore, the O-ring can be mounted in the vicinity of the O-ring seal groove or the O-ring seal groove of the grip member mounting portion before the gauge member and the grip member are assembled. Since there is no need to pass through the member and the O-ring can be moved at a considerably shorter distance, work efficiency can be improved.
[0029]
In addition, when the O-ring is mounted, it does not pass through the edge or burr of the metal gauge member, so that damage to the O-ring due to the edge or burr can be avoided and good sealing performance can be obtained. it can.
Therefore, an oil level gauge including a metal gauge body, a resin grip, and an O-ring can be manufactured with extremely high productivity. As a result, the oil level gauge can be provided at low cost.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an oil level gauge according to the present invention.
FIG. 2 is a front view of an oil level gauge according to the present invention.
FIG. 3 is a side sectional view for explaining a method for producing an oil level gauge by an ultrasonic welding method.
FIG. 4 is a front view showing a state in which an oil level gauge is attached to a guide tube.
FIG. 5 is a perspective view of an oil level gauge.
FIG. 6 is a front view showing attachment of an O-ring to an oil level gauge.
FIG. 7 is a schematic side sectional view of an engine for explaining a relationship between an oil level gauge and an oil tank.
FIG. 8 is a side sectional view for explaining a method of manufacturing an oil level gauge by an insert method.
FIG. 9 is a side sectional view for explaining a method of manufacturing an oil level gauge by an electromagnetic induction heating method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 1a Mounting port 2 Oil tank 2a Oil 3, 30 Oil level gauge 4 Gauge member 4a Front end part 4b Fixing part 5 Mounting part 5a O ring seal groove 5b Stopper part 6 Grip part 7 O ring 8 Grip member 8a Receptacle 8b Cover Body 8c mating surface 10 guide tube
13 Fitting hole 60 Ultrasonic vibrator D Longitudinal division position H Upper limit mark L Lower limit mark

Claims (2)

An O-ring seal groove for the O-ring is provided around the cylindrical mounting portion of the grip member made of synthetic resin, and the gauge member fixing portion is inserted in the axial direction of the mounting portion on the tip side of the O-ring seal groove. A fixing hole is formed by opening a fitting hole for fixing, dividing the mounting portion along the fitting hole on the tip side of the O-ring seal groove, and a receiver. An oil level gauge characterized by sandwiching and assembling between the lid and the receiver in a state in which the lid is inserted into the fitting hole, and ultrasonically welding a joint surface between the lid and the receiver . After the O-ring is mounted on the mounting portion in the O-ring seal groove or in the vicinity of the O-ring seal groove, the fixing portion is fitted into the fitting hole, and the lid and the receiver are fixed. 2. The method for producing an oil level gauge according to claim 1, wherein a part is sandwiched and assembled, and a joint surface between the lid and the receiver is ultrasonically welded.

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