JP2004060688A - Packing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packing having improved durability by preventing a main lip from being held in a gap between an insert metal and a piston rod. <P>SOLUTION: The packing comprises the circular insert metal 16, a seal body 13 of U-shaped cross section welded upward to the outer periphery of the insert metal, an outer periphery lip 14 integrally formed on the outer periphery side of the seal body, and the main lip 15A integrally formed on the inner periphery side of the seal body. A rising portion at a base end 15b of a main seal is arranged on the inner periphery of the seal body an arbitrary distance upward from the inner periphery upper end of the insert metal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a packing used as a seal member of a hydraulic or pneumatic device, and in particular, a back door interposed between a vehicle body and a back door, between a vehicle body and an engine hood, or a window of a building, The present invention relates to a packing suitable for use of a gas spring for improving opening and closing operations of an engine hood or a window.
[0002]
[Prior art]
Generally, in vehicles such as automobiles, for example, a gas spring that is constantly urged in the direction of extension by gas pressure is interposed between the vehicle body and the back door, and when the back door is unlocked, the gas spring is attached. The back door is slowly and automatically opened by power. As this gas spring, for example, the one shown in FIG. 8 has been developed.
[0003]
That is, a piston rod 3 is movably inserted into a cylinder 1 via a piston 2, and the piston 2 partitions a gas chamber 4 and an oil chamber 5 in the cylinder 1, and the gas chamber 4 and the oil chamber 5 are separated from each other. It is connected via a port 6 formed in the piston 2. The piston rod 3 is guided in the axial direction by a bearing 7 and a retainer 8 provided near the end of the cylinder 1 and at an intermediate portion thereof, and the retainer 8 prevents the piston 2 from contacting a packing 9 which is a seal described later. ing.
[0004]
In the vicinity of the end of the cylinder 1, a packing 9 is provided on the upper surface serving as the inner end of the bearing 7, and a dust seal 10 is provided on the lower surface serving as the outer end of the bearing 7.
[0005]
One end of the cylinder 1 is connected via a bracket 11 to, for example, a back door of an automobile, and an end 12 of the piston rod 3 is connected to the vehicle body side. When the back door is unlocked, the piston rod is driven by the gas pressure in the gas chamber 4. 3 extends and automatically opens the back door. At this time, the piston rod 3 is slowly extended while being attenuated by the flow resistance of the gas flowing through the port 6, so that no impact is applied to the back door.
[0006]
The packing 9 prevents gas and oil in the cylinder 1 from leaking to the outside, and the dust lip 10 prevents dust from entering the cylinder from outside.
[0007]
The packing 9 has a single lip structure, as shown in FIGS. 5, 6, and 7, a seal main body 13 made of rubber or the like, an outer peripheral lip 14 provided on the outer peripheral side of the seal main body 13, and an inner peripheral side of the seal main body 13. , And an insert metal 16 embedded and fused in the seal body 13. The base end 15a of the main lip 15 is joined to a position close to the upper end of the inner periphery of the insert metal 16.
[0008]
The main lip 15 slides on the outer circumference of the piston rod 3 to prevent gas and oil from leaking from the outer circumference of the piston rod 3 to the outside, and the outer lip 14 abuts on the inner circumference of the cylinder 1 and It also prevents gas and oil from leaking.
[0009]
[Problems to be solved by the invention]
When the conventional packing 9 is stationary, the state shown in FIG. 5 is maintained. When the packing 9 is inserted into the cylinder 1 and the piston rod 3 is inserted inside the main lip 15 as shown in FIG. And the main lip 15 is compressed and pressed against the inner circumference of the cylinder 1 and the outer circumference of the piston rod 3 with an arbitrary interference. In this state, when the piston 8 slides and the internal pressure of the oil chamber 5 increases, the main lip 15 is pressed by the internal pressure in the direction of arrow A as shown in FIG. The lower portion of the main lip 15 may be deformed and protrude from the base end 15a into a gap between the main lip 15 and the main lip 15 to be pinched. Therefore, if this state is repeated, a high frictional force is generated against the piston rod 3, so that not only the sliding resistance of the piston rod 3 is increased, but also the main lip 15 is worn and the life is shortened.
[0010]
Accordingly, an object of the present invention is to provide a packing that can prevent the main lip from being caught in a gap between the insert metal and the piston rod and can improve durability.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the means of the present invention comprises an annular insert metal, a seal body having a U-shaped cross section fused upward to the outer periphery of the insert metal, and integrally formed on the outer peripheral side of the seal body. In the packing consisting of the outer lip and the main lip integrally formed on the inner peripheral side of the seal main body, the base end of the main lip is located at an inner periphery of the seal main body at an arbitrary distance above the inner peripheral upper end of the insert metal. A rising portion is arranged.
[0012]
Similarly, the other means includes an annular insert metal, a seal body having a U-shaped cross section fused upward to the outer periphery of the insert metal, an outer peripheral lip integrally formed on the outer peripheral side of the seal body, In a packing comprising a main lip integrally formed on an inner peripheral side, an annular concave portion is formed on an inner peripheral surface of a seal body between an inner peripheral upper end of the insert metal and a base end of the main lip. .
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
[0014]
1 to 3 show a packing 9A according to one embodiment of the present invention, and FIG. 4 shows a packing 9B according to another embodiment.
[0015]
The packing 9A in FIG. 1 shows a stationary state, FIG. 2 shows a deformed state of the packing 9A in a state in which the packing 9A is inserted into the cylinder 1, and the piston rod 3 is inserted in the main lip 15A, and FIG. The state of deformation of the packing 9A when an internal pressure in the direction of arrow A acts on the cylinder 1 is shown.
[0016]
Since the gas spring to which the packing 9A is attached is the same as that of the conventional example shown in FIG. 8, details of the same members will be omitted by using the same reference numerals.
[0017]
As in the prior art, the packing 9A of FIG. 1 is formed integrally with an annular insert metal 16, a seal body 13 having a U-shaped cross section which is fused upward to the outer periphery of the insert metal 16, and an outer peripheral side of the seal body 13. And a main lip 15A integrally formed on the inner peripheral side of the seal body 13. In the present invention, the rising portion of the base end 15b of the main lip 15A is arranged on the inner periphery of the seal main body at a position separated by an arbitrary width L from the upper end of the inner periphery of the insert metal 16.
[0018]
According to the packing 9A, as shown in FIG. 2, when the piston 1 is inserted into the cylinder 1 and the piston rod 3 is inserted inside the main lip 15A, the dust lip 14 and the main lip 15A become the inner circumference of the cylinder 1 and the outer circumference of the piston rod 3, respectively. It is deformed and pressed. At this time, since the base end 15b of the main lip 15A is located above the inner peripheral upper end of the insert metal 16 by the width L only, this portion looks as if the meat is cut out. Further, in this state, the internal pressure rises, and when this internal pressure acts on the main lip 15A as shown by an arrow A, as shown in FIG. Hang in the B direction. However, the raised portion does not enter the gap B, and is not caught between the insert metal 16 and the piston rod 3, so that the frictional resistance does not increase or wear, and the internal pressure acts repeatedly. Can also prevent the loss of durability.
[0019]
Next, the packing 9B of FIG. 4 according to another embodiment is similar to the above, and has a ring-shaped insert metal 16 and a seal body 13 having a U-shaped cross-section fused upward to the outer periphery of the insert metal 16 and a seal body 13 And a main lip 15A integrally formed on the inner peripheral side of the seal body 13. An annular recess 15c is formed on the inner periphery of the seal body 13 between the upper end of the inner periphery of the insert metal 16 and the base end 15b of the main lip 15A.
[0020]
In this case, as in FIGS. 2 and 3, the U packing 9B is mounted in the cylinder 1, and when the internal pressure acts on the U packing 9B, the meat is cut off in advance in the concave portion 15c. Even if the main lip 15A is deformed by being pressed, the lower portion of the main lip 15A is prevented from biting and being caught in the gap B between the insert metal 16 and the piston rod 3, and the durability of the main lip 15A is improved, and the service life is improved. Can be extended.
[0021]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0022]
1) According to the first aspect of the present invention, the base rising portion of the main lip is disposed above the upper end of the inner periphery of the insert metal. The lower portion of the main lip does not enter the gap between the insert metal and the piston rod, preventing an increase in frictional resistance, and at the same time, does not wear out, thereby improving durability.
[0023]
2) According to the second aspect of the present invention, since an annular recess is formed in the inner periphery of the seal body between the base end of the main lip and the upper end of the inner periphery of the insert metal, the internal pressure acts on the main lip to compress it. Even if this is done, the lower part of the main lip does not enter the same gap as above, preventing an increase in frictional resistance, preventing abrasion, and improving durability.
[Brief description of the drawings]
FIG. 1 is a partially enlarged sectional view of a packing according to an embodiment of the present invention.
FIG. 2 is a partially enlarged sectional view of a packing inserted into a cylinder.
FIG. 3 is a partially enlarged cross-sectional view of a packing in a state where an internal pressure acts in a cylinder.
FIG. 4 is a partially enlarged cross-sectional view of a packing according to another embodiment.
FIG. 5 is a partially enlarged sectional view of a conventional packing.
FIG. 6 is a sectional view of the packing of FIG. 5 in a state where the packing is mounted in a cylinder.
FIG. 7 is a sectional view of the packing of FIG. 5 when an internal pressure is applied.
FIG. 8 is a sectional view of a gas spring equipped with a conventional packing.
[Explanation of symbols]
13 Seal body 14 Outer peripheral lip 15A Main lip 15b Base end 15c Annular recess 16 Annular insert metal

Claims (2)

An annular insert metal, a seal body having a U-shaped cross-section fused upward to the outer periphery of the insert metal, an outer peripheral lip integrally formed on the outer peripheral side of the seal main body, and integrally formed on an inner peripheral side of the seal main body. A packing comprising a main lip formed therein, wherein a base rising portion of the main lip is arranged on an inner periphery of the seal body at a position apart from the inner peripheral upper end of the insert metal by an arbitrary width. An annular insert metal, a seal body having a U-shaped cross-section fused upward to the outer periphery of the insert metal, an outer peripheral lip integrally formed on the outer peripheral side of the seal main body, and integrally formed on an inner peripheral side of the seal main body. A packing comprising a formed main lip, wherein an annular concave portion is formed on an inner periphery of a seal body between an inner peripheral upper end of the insert metal and a base end of the main lip.

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