JPH0558693U - Tank drain plug - Google Patents

Abstract

(57) [Summary] [Purpose] In a drain plug for closing the drain port of an oil tank or fuel tank, the desired contact surface pressure can be obtained with the same tightening force even when a gasket with high hardness is used. To [Structure] A screw shaft portion 2 that is screwed into a drain port 7 of a tank 5 and a flange portion 3 that is pressed against a sealing surface 8 formed at a peripheral portion of the drain port 7 via a gasket 9 In the drain plug 1 having a shape, a ring-shaped protrusion 4 is provided on the contact surface of the flange portion 3 with the gasket 9. The contact between the gasket 9 and the plug is the protrusion 4.
Therefore, the desired contact surface pressure can be obtained even for the gasket 9 having high hardness.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a drain plug for closing a drain port set at the bottom of a tank such as an oil tank or a fuel tank equipped in an industrial vehicle such as a forklift.

[0002]

[Prior Art]

 Conventionally, a T-shaped drain plug 21 including a screw shaft portion 22 and a flange portion 23 as shown in FIG. 4 has been used as a drain plug for closing a drain port of an oil tank or a fuel tank of a forklift. In this drain plug 21, a screw shaft portion 22 is screwed into a drain port 26 formed by a boss 25 fitted to the bottom portion of a tank 24 constituted by a frame, and a sealing surface 27 provided on the boss 25 is provided. The gasket 28, which is interposed between the flange portion 23 and the flange portion 23, is compressed to deform the gasket 28, thereby obtaining a liquid sealing effect. The drain plug 21 is generally attached to and detached from the drain port 26 by inserting a T-shaped wrench (not shown) into a square hole 23a provided in the center of the flange portion 23.

[0003]

[Problems to be solved by the device]

 However, the conventional drain plug 21 described above has the following problems. In other words, the seal surface 27 formed on the boss 25 may be scratched or weld spatter adheres. In such a case, the gasket 28 that is always used is used when the drain plug 21 is screwed. Since the gasket 28 will be damaged by scratches on the seal surface 27, welding spatter, etc., it is possible to deal with it by using a gasket 28 having a hardness higher than that of the regular gasket 28 at the operator's discretion.

However, when the gasket 28 having a high hardness is used, a larger contact surface pressure is required than in the case of the regular gasket. Therefore, even if the worker determines that the gasket 28 has been tightened with a sufficient tightening force, the contact area of the gasket 28 is large and the contact surface pressure of the gasket 28 is high due to the manual work with the T-wrench. Is likely to be insufficient, and as a result there was a risk of oil leakage.

In view of the above problems, the present invention is an improved drain plug that is capable of easily obtaining a predetermined contact surface pressure with the same tightening force even when a gasket having high hardness is used. To provide a technical problem to be solved.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention is configured as follows. That is, a drain plug for closing a drain port provided at the bottom of a tank, including a screw shaft portion to be screwed into the drain port and a base portion of the screw shaft portion, and the drain port. A flange portion that seals the drain port by being pressed through a gasket against the sealing surface formed on the peripheral portion of the flange portion, and a ring-shaped protrusion is formed on the contact surface of the flange portion with the gasket. It is characterized by what was done.

[0007]

[Action]

 In the drain plug according to the present invention configured as described above, the gasket interposed between the flange portion and the sealing surface of the drain port when mounted on the drain port has the ring-shaped gasket formed on the flange portion. It is pressed by the protrusions. In this case, since the contact area to be pressed is smaller than that applied to the entire surface of the flange, it is possible to obtain a large contact surface pressure with the same tightening force, and even with a gasket of high hardness The sealing effect of is obtained.

[0008]

Embodiment An embodiment of the present invention will be specifically described below with reference to the drawings. 1 shows the front of the drain plug, and FIG. 2 shows the plane of the drain plug. The drain plug 1 in this embodiment is a T-shaped plug as shown in the drawing, and is composed of a screw shaft portion 2 and a circular flange portion 3 provided at the base of the screw shaft portion 2. A ring-shaped projection 4 having a rectangular cross section is integrally formed on the sealing surface side of the flange portion 3, that is, on the contact surface side of the gasket 9.

On the other hand, FIG. 3 shows a state in which the drain plug 1 configured as described above is attached to the drain port 7. As shown in the figure, a boss 6 is fitted into the bottom of the tank 5 and fixed by welding. A drain port 7 with a female screw is formed on the boss 6, and the lower edge of the drain port 7 is formed. A seal surface 8 for interposing a gasket 9 is formed in a counterbore shape on the side of the portion.

The drain plug 1 is screwed into the drain port 7 while the ring-shaped gasket 9 is fitted in the screw shaft portion 2 in advance. This screwing is performed by fitting a T-shaped wrench (not shown) into the square hole 3a formed in the center of the flange portion 3 and rotating this, and in this case, the drain plug 1 of this embodiment uses the flange portion 3a. Since the ring-shaped projection 4 is provided on the contact surface side with the gasket 9, the gasket 9 is pressed against the sealing surface 8 of the boss 6 by the projection 4.

As described above, when the gasket 9 is pressed by the protrusions 4, the contact area under pressure can be reduced. Therefore, compared with the case where the entire surface of the flange portion 3 is pressed, the contact force against the tightening force is reduced. The pressure increases. Therefore, according to the drain plug 1 of the present embodiment, when the sealing surface 8 of the boss 6 is scratched or weld spatter is adhered and the currently used gasket cannot be used, The desired sealing effect can be obtained by using a gasket with higher hardness and tightening it with the same plug tightening force as before.

Of course, in the drain plug 1 with a protrusion of the present embodiment, if there is no problem in the state of the sealing surface 8, it is possible to close the drain port 7 by using a regular gasket having the existing hardness. In this case, when the drain plug 1 is tightened with the same level of tightening force as the conventional one, the contact surface pressure of the gasket 9 naturally becomes higher than that in the case of using the existing drain plug without protrusions. If this causes adverse effects (damage to the gasket, etc.), then the tightening force should be slightly weakened or the drain plug with protrusion 1 and the drain plug without protrusion should be used properly. It is possible.

In the present embodiment, the protrusion 4 is provided so as to form one ring on the flange portion 3 and has a rectangular cross-sectional shape. However, even if a plurality of protrusions 4 are provided, Moreover, even if the cross-sectional shape is changed from rectangular to arc or mountain, the intended purpose can be achieved.

[0014]

[Effect of the device]

 As described above in detail, according to the drain plug of the present invention, when a situation in which a gasket having a hardness higher than that of a conventional one is desired to be used, a high contact surface pressure, which is difficult to obtain with the conventional drain plug, can be easily achieved. It becomes possible to obtain oil, and it is very effective in preventing oil leakage due to insufficient contact surface pressure.

[Brief description of drawings]

FIG. 1 is a front view of a drain plug according to an embodiment of the present invention.

FIG. 2 is a plan view of the drain plug of the same.

FIG. 3 is a cross-sectional view showing how the drain plug is attached to the drain port.

FIG. 4 is a sectional view showing a conventional drain port and its mounting state.

[Explanation of symbols]

 1 ... Drain plug 2 ... Spiral shaft part 3 ... Flange part 4 ... Protrusion 5 ... Tank 7 ... Drain port 8 ... Sealing surface 9 ... Gasket

Claims (1)

[Scope of utility model registration request] 1. A drain plug for closing a drain port provided at the bottom of a tank, comprising a screw shaft portion screwed into the drain port and a base portion of the screw shaft portion, and the drain port of the drain port. A tank having a flange portion that seals the drain port by being pressed through a gasket against a sealing surface formed on a peripheral portion, and a ring-shaped projection is formed on a contact surface of the flange portion with the gasket. Drain plug.