JPH071550Y2 - Sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a sealing device which comes into contact with an outer peripheral surface of a movable shaft slidably supported by a guide member.

(Prior Art) A conventional sealing device of this type is shown in FIG. In the figure,
100 is an annular guide member, 101 is an inner peripheral surface 1 of the guide member 100.
It is a movable shaft that is held in sliding contact with 00a and operates in the direction of the arrow. Reference numeral 102 denotes a sealing device mounted on the outer peripheral surface of the guide member 100. The sealing device 102 has a reinforcing ring 103, a seal member 104 that contacts the outer peripheral surface of the movable shaft 101 to seal the fluid Z, and a contact force of the seal member. And a spring 105 that enhances the

The tip end 106 of the seal member 104 is contacted with the fluid Z side and the guide member 100 side while maintaining preset angles a and b (a> b is a dead seal, a <b is a supply seal). The movable shaft 101 and the tip 106 of the seal member 104 during operation.
By supplying a fixed amount of the fluid Z on the sealed side to the sliding contact portion c between the inner peripheral surface 100a of the guide member 100 and the movable shaft 101 via a contact portion with the movable shaft 101, malfunction of the movable shaft 101 or sliding portion c It is taken as a measure to prevent the image sticking.

(Problems to be solved by the invention) However, since the amount of the fluid Z consumed in the sliding portion c varies depending on the operating condition of the movable shaft 101, etc., the tip 106 is previously processed by a molding die or finish. Due to the formed angles a and b, a certain amount of the fluid Z supplied as a film on the guide member side cannot cope with the situation, and the necessary amount of the fluid Z is insufficient to cause malfunction or seizure. However, there is a waste of supplying the fluid Z more than necessary.

This invention solves the above problem and prevents the supply of wasteful fluid by automatically adjusting the fluid supply in accordance with the required amount of fluid consumed at the sliding portion between the movable shaft and the guide member. An object of the present invention is to provide a sealing device capable of preventing malfunction of a movable shaft and seizure of a sliding portion caused by insufficient fluid supply.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a sealed fluid inside a housing by contacting a tip end portion along an outer peripheral surface of a movable shaft slidably supported by a guide member. Side and a guide member side, a seal member is provided, and a slant surface for holding a predetermined inclination angle toward the movable shaft is formed at the tip end in the opposite direction, so that the sealing fluid is guided to the guide member side when the movable shaft operates. In a sealing device that can be supplied, a reversible stretchable body that axially presses the tip of the seal member by absorbing and expanding the sealing fluid is mounted between the tip of the seal member and the guide member. The expansion / contraction of the expandable / contractible body changes the inclination angle of the tip portion to adjust the supply amount of the sealing fluid.

(Operation) The operation of the present invention based on the above configuration is excessive when the amount of fluid supplied from the tip end portion of the seal member to the guide member side exceeds the fluid consumption amount at the sliding portion between the guide member and the movable shaft. The elastic body absorbs and expands the amount, and presses the tip portion of the seal member in the axial direction. As a result, the inclination angle of the tip portion changes to a state where the fluid supply amount decreases. Further, when the former supply amount falls below the latter consumption amount, the elastic body contracts. as a result,
The tilt angle varies to increase the supply fluid.

(Embodiment) Next, this invention will be described based on an embodiment shown in FIGS. 1 and 2.

In FIG. 1, 1 is a guide member, 2 is a movable shaft such as a valve stem slidably inserted in and held on an inner peripheral surface 1a of the guide member 1, and the movable shaft 2 reciprocates along the axial direction. .

3 is a sealing device mounted on the outer peripheral surface of the guide member 1. The sealing device 3 is an annular seal member 5 formed of rubber or the like, and a reinforcement having an L-shaped cross section made of metal or the like fixed to the seal member 5. A spring 7 for maintaining the contact pressure between the ring 6 and the tip 5a of the seal member 5 which is in sealing contact with the outer peripheral surface of the movable shaft 2.
It consists of and. Thus, the sealed fluid A side such as oil and the guide member 1 side are separated.

In addition, the tip portion 5a of the seal member 5 has a predetermined inclination angle α (sealing fluid A side), β (guide member 1 side) toward the movable shaft 2.
The slopes 8 and 9 for holding are formed in the opposite direction. Normally, when the inclination angle α> the inclination angle β is set, the sealing fluid A adheres in a film form to the contact surface between the tip portion 5a and the movable shaft 2 during the operation of the movable shaft 2 and is supplied to the guide member 1 side. When the movable shaft 2 is actuated, the sealing fluid A adheres to the contact surface between the tip 5a and the movable shaft 2 in a film shape when the movable shaft 2 is operated. The amount supplied to the guide member 1 side increases. Therefore, the slopes 8 and 9 are formed so as to maintain the inclinations α and β (the amount consumed by the sliding portion 1a between the movable shaft 2 and the guide member 1) based on the conditions of use.

A groove 5b is provided on the inner peripheral surface of the seal member 5.

Reference numeral 10 denotes a ring-shaped expandable body mounted between the tip portion 5a of the seal member 5 and the guide member 1. The expandable body 10 has a protrusion 10a formed along the outer peripheral surface thereof. It is fitted in the groove 5b of the seal member 5. Further, one side surface is in contact with the guide member 1, and the inner peripheral surface is in contact with the movable shaft 2.
Further, there is a gap between the outer peripheral surface of the ridge 10 and the groove 5b. The elastic body 10 has a characteristic that it expands when it absorbs the sealing fluid A such as oil, and it contracts to its original state when the amount of the absorbed sealing fluid A decreases, and it uses a reversible fluid-absorbent resin or the like. Satisfied with using.

Next, the operation of the above embodiment will be described.

When the movable shaft 2 is stationary, the sealing fluid A is sealed by the seal member 5 and is not supplied to the guide member 1 side.

Next, when the movable shaft 2 starts to operate along the axial direction, the sealing fluid A attached to the outer peripheral surface of the movable shaft 2 forms a film through the tip portion 5a of the seal member 5 during the downward operation in the drawing. Then, it reaches the guide member 1 side and is absorbed by the stretchable body 10. Stretchable body
A certain amount of the amount absorbed by 10 is consumed at the sliding portion B between the outer peripheral surface of the movable shaft 2 and the guide member 1, and malfunctions and seizure are prevented. During the operation of the movable shaft 2, while the amount of the sealing fluid A consumed at the sliding portion B is balanced with the amount of the sealing fluid A supplied by the preset inclination angles α and β, the expansion / contraction body 10 is expanded. No expansion or contraction (Fig. 1, l ₁ ).

When the amount of the sealing fluid A consumed in the sliding portion B decreases for some reason, the excessive supply amount is absorbed and accumulated in the elastic body 10, and the elastic body 10 expands as shown in FIG. . Then, the expansion of the elastic body 10 in the outer peripheral direction is canceled by the ridge 10a filling the gap with the groove 5b of the seal member 5. The expansion l _{2 in the} axial direction causes the side surface (upper side in the figure) of the protrusion 10a to push the groove 5b upward because one side surface of the expandable body 10 is in contact with the guide member 1, so that Tip
5a is pressed along the axial direction of the movable shaft 2.

Therefore, the inclination angle α increases to α ′ and β decreases to β ′, so that the sealing fluid A is supplied to the guide member side from the contact portion between the tip portion 5a of the seal member 5 and the movable shaft 2. The amount of waste will be reduced. As a result, it is possible to prevent supply of the sealing fluid A to the sliding portion B more than necessary.

On the contrary, if the consumption of the sealing fluid A in the sliding portion B increases,
Since the sealing fluid A accumulated in the elastic body 10 gradually decreases, the sealing fluid A contracts depending on the characteristics of the elastic body 10. Then, the tip portion 5a of the seal member 5 is axially deformed by the elastic force, that is, returns to its original state, and the inclination angles α'and β'with the tip portion 5a and the outer peripheral surface of the movable shaft 2 are also α, It will return to β. As a result, the amount of the sealing fluid A supplied to the sliding portion B increases to prevent malfunction or seizure.

During the above operation, the expandable / contractible body 10 stops expansion / contraction while maintaining the optimum supply amount of the sealing fluid A consumed in the sliding portion B. The two modes of FIG. 1 and FIG. It doesn't change only in.

(Effect of the Invention) Since the present invention is configured as described above, the supply amount of the sealed fluid is automatically adjusted according to the required amount of the fluid consumed at the sliding portion between the movable shaft and the guide member. it can. Therefore, it is possible to prevent the useless supply of the fluid and prevent the malfunction of the movable shaft and the seizure of the sliding portion caused by the insufficient supply of the fluid.

[Brief description of drawings]

1 and 2 are front sectional views showing an embodiment of the present invention,
FIG. 3 is a front sectional view showing a conventional example. DESCRIPTION OF SYMBOLS 1 ... Guide member, 2 ... Movable shaft 3 ... Sealing device, 4 ... Housing 5 ... Seal member, 5a ... Tip of seal member 8, 9 ... Slope, 10 ... Expandable body α, α ', β, β ′… Inclination angle

Claims (1)

[Scope of utility model registration request] 1. A seal member is provided, which divides the inside of the housing into a sealed fluid side and a guide member side by contacting a tip end portion along an outer peripheral surface of a movable shaft slidably supported by the guide member, In the sealing device in which a slanting surface for holding a predetermined inclination angle toward the movable shaft is formed in the end portion in an anti-reverse manner so that the sealing fluid can be supplied to the guide member side when the movable shaft is actuated. A reversible stretchable body that presses the tip end portion of the seal member in the axial direction by absorbing and expanding the sealing fluid is mounted between the portion and the guide member, and the tip end portion is expanded and contracted by the stretchable body. A sealing device that adjusts the supply amount of the sealing fluid by changing the inclination angle of.