JPS6357678B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cap device attached to an oil tank filler tube.

For example, in the oil tank of an automobile's power steering system, a vent hole is provided in the cap of the oil filler cylinder in order to compensate for fluctuations in the internal pressure of the oil tank due to temperature changes. In this case, oil may leak out from the cap when the oil tank vibrates or tilts, so conventionally the cap was constructed as shown in Figure 1 to prevent oil leakage.

The cap body 1 is provided with a level gauge core rod 3 that is inserted into the oil supply tube 2, and a plurality of baffle plates 5 are attached to the core rod 3 in parallel so as to form a meandering passage 4. The inside of the oil tank (not shown) is communicated with the outside through the passage 4 to keep the internal pressure of the oil tank constant, and the baffle plate 5 buffers the wave motion of the internal oil to prevent the oil from flowing out to the outside. It is now possible to prevent it.

However, there is a problem in that it is not possible to prevent the internal oil from flowing out when the oil tank is tilted significantly and the oil filler cylinder 2 is located below the oil level, or when the valve is opened to release the internal pressure.

The present invention was made to solve this problem. Under normal conditions, the oil filler cylinder is kept sealed to completely prevent oil from flowing out, and the air pressure in the oil tank rises or exceeds the set value. When the pressure drops, the first and second check valves take in outside air or release the internal pressure to keep the internal pressure of the oil tank constant and prevent oil from leaking no matter how the valve operates. The object of the present invention is to provide a cap device that can perform the following functions.

Therefore, in the present invention, the first check valve is fixed to the core rod attached to the cap body, and a lip portion is formed on the outer periphery of the first check valve, which is in close contact with the inner circumferential wall of the oil supply cylinder and bends elastically according to the tank internal pressure. Inside the first check valve, a second check valve consisting of a cap-shaped valve body that can freely slide on the core rod is provided so that its operating direction is different, and the flat bottom part of the cap-shaped valve body is connected to the first check valve. The small hole passing through the check valve can be opened and closed according to the elastic force of the spring and the internal pressure of the tank, and the outer cylindrical part of the cap valve body that constitutes the second check valve can be slid against the inner peripheral wall of the oil tank. They were placed in close contact with each other to obtain the above effect.

Embodiments of the present invention will be described below with reference to the drawings.

The core rod 3 of the cap body 1 extends into the oil tank through the oil filler tube 2, and a level cage 6 is provided at the tip thereof.

The part of the core rod 3 located in the oil supply cylinder 2 has a
First and second check valves 7 and 8 are installed.

The first check valve 7 has a lip portion 10 formed on the circumferential surface of a cylindrical body 9 made of an elastic member such as rubber.

The lip portion 10 is bent toward the opening 2a of the oil filler cylinder 2 and separated from the inner surface thereof when the internal pressure of the oil tank increases to a predetermined value.

The cylindrical body 9 of the first check valve 7 is formed with a small hole 11 passing through it in the axial direction.

Further, a packing part 13 is connected to the cylindrical body 9 via a neck part 13a, and this packing part 13 is connected to the oil supply cylinder 2.
A vertical groove 13b is formed on the circumferential surface in contact with the inner surface of the
Air from the outside of the oil filler cylinder 2 is passed through the vertical groove 13b into the small hole 1.
1.

This first check valve 7 is inserted into the core rod 3 through a hole 14 passing through its axis, and with the upper end of the packing part 13 in contact with the cap body 1, the core rod 3 is pressed by a caulked part 15a. Fixed.

On the other hand, in the second check valve 8 disposed below the first check valve 7, the flat bottom part of the cap-shaped valve body 17 comes into contact with and separates from the end face of the cylindrical body 9, so that the oil tank internal pressure is lower than the set value. When lowered, the small hole 11 opens against the force of the spring 16.

The cap-shaped valve body 17 of the second check valve 8 is slidably guided by the core rod 3, and the outer cylindrical portion of the cap-shaped valve body 17 slides against the inner circumferential wall of the oil supply cylinder 2 with its entire circumference in close contact. A coil spring 16 is interposed between a spring retainer 18 that is movably guided and is locked to the core rod 3 via a caulking portion 15b.
As a result, the small hole 11 of the first check valve 7 is always urged in the direction of closing by the flat bottom portion of the cap-shaped valve body 17.

In the figure, reference numeral 19 denotes a metal valve seat joined to the end face of the first check valve 7, which prevents adhesion between the first check valve 7 and the valve body 17, which are made of an elastic material such as rubber.

Next, the action will be explained.

Under normal conditions, the lip portion 9 of the first check valve 7 elastically comes into close contact with the inner surface of the oil filler cylinder 2, and the flat bottom portion of the cap-shaped valve body 17 of the second check valve 8 is also pressed by the spring 16. Since it is pressed against the valve seat 19 and closes the small hole 11, and its outer cylindrical portion is tightly fitted to the inner surface of the oil filler cylinder 2, the oil tank is maintained in a sealed state. Therefore, even if the internal oil shakes due to vibrations or the oil tank is tilted significantly, the lip portion 9 of the first check valve 7 and the cylindrical portion of the second check valve 8 will remain in two stages relative to the inner circumferential wall of the oil filler cylinder 2. Therefore, oil leakage is reliably prevented, and no oil leaks from the cap body 1 at all.

On the other hand, when the internal pressure of the oil tank rises above a predetermined value due to temperature rise, the lip portion 10 of the first check valve 7 is pushed outward by the internal pressure.
away from the inner surface of the oil filler cylinder 2. As a result, the air inside the oil tank escapes to the outside through the gap formed between the first check valve 7 and the inner surface of the oil filler cylinder 2, and the internal pressure of the oil tank decreases. Note that the air in the tank flows through the outer peripheral sliding part gap and hole 17a (see Fig. 3) of the cap-shaped valve body 17, and then flows through the valve seat 1.
9 and the valve body 17 to push and bend the lip portion 10 and release the lip portion 10.
0 is in the open state, the outer cylindrical portion of the cap-shaped valve body 17 of the second check valve 8 is in close contact with the inner circumferential wall of the oil filler cylinder 2, so that oil is prevented from gushing out and only gas is released. can be released from the first check valve 7.

Furthermore, when the internal pressure of the oil tank falls below the set value, the lip portion 10 is pressed against the inner surface of the oil filler cylinder 2 by the outside air, but the valve body 17 of the second check valve 8 is pressed against the spring by the differential pressure with the outside air. It moves against the elastic force of 16 and opens the small hole 11. Therefore, atmospheric air is introduced into the oil tank through the small hole 11, increasing the internal pressure.

In this way, the oil tank is always maintained at a normal internal pressure by the first check valve 7 and the second check valve 8, and oil leakage from the oil filler cylinder 2 can be completely prevented.

The packing part 13 has the function of equalizing the contact pressure of the lip part 10 of the first check valve 7 over the entire circumference and also of preventing oil leakage.

By the way, the elastic means of the second check valve 8 is not limited to the coil spring 15;
For example, as shown in FIG.
A plate spring 15a may be used instead of the spring 5.
The leaf spring 15a is formed into a bow shape and inserted into a window 20 provided in the core rod 3, and elastically supports the cap-shaped valve body 17 from the inside.

As explained above, the present invention first provides an arrangement structure in which a first check valve and a second check valve whose operating directions are different from each other are arranged in a two-stage all-around contact structure in which they are arranged in series with the inner wall of an oil supply cylinder. With this structure, the internal pressure of the oil tank can be kept constant at all times, preventing problems such as poor oil supply caused by large fluctuations in internal pressure. Even during the release operation, a cap-shaped second check valve is located inside the lip of the first check valve for internal pressure release on the tank side, and the cylindrical part that fits with the inner periphery of the oil cylinder prevents the oil from inside the oil cylinder. Since a two-stage seal is formed on the peripheral wall, oil leakage from the oil filler tube can be reliably prevented.

Next, the first check valve is provided with a lip that is in close contact with the inner circumferential wall of the oil supply cylinder and that bends elastically in accordance with the tank internal pressure.In other words, the check valve is constructed by deformation of the seal lip, so the check valve structure is improved. It is possible to achieve the effects of simplifying the process, reducing the number of component parts, and reducing production costs.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view showing the conventional cap installed, FIG. 2 is a cross-sectional view showing the cap device of the present invention installed, and FIG. 3 is a perspective view showing the same disassembled state.
FIG. 4 is a perspective view showing another embodiment of the second check valve. DESCRIPTION OF SYMBOLS 1... Cap body, 3... Core rod, 7... First check valve, 8... Second check valve, 10... Lip portion, 11... Small hole, 15... Spring, 17
... Valve body.

Claims (1)

[Claims] 1. A first check valve is fixed to a core rod attached to a cap body, and a lip portion is formed on the outer periphery of the first check valve, which is in close contact with the inner peripheral wall of the oil supply cylinder and bends elastically according to the internal pressure of the tank. A second check valve consisting of a cap-shaped valve body that can freely slide on the core rod is provided on the inside of the valve so that its operating direction is different, and the flat bottom portion of the cap-shaped valve body penetrates the first check valve. The small hole in the oil tank can be opened and closed according to the elastic force of the spring and the internal pressure of the tank, and the outer cylindrical part of the cap-shaped valve body constituting the second check valve is brought into close contact with the inner peripheral wall of the oil cylinder so that it can slide. 1. A cap device for an oil tank for an oil tank, characterized in that air inside the tank is released through a gap and a hole in the outer circumferential sliding part of a cap-shaped valve body according to the internal pressure of the tank.