JP3621966B2 - Bellows end sealing structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device for sealing an end of a bellows used for a pressure control valve, a displacement control valve for a variable compressor, and the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a bellows is used to detect a fluid pressure and drive a valve in a displacement control valve for a variable swash plate type compressor used for a pressure regulating valve, a car air conditioner, or the like. Since the bellows operates by receiving fluid pressure on one or both sides thereof, a certain seal is required so that no fluid leaks from a fixed portion around the bellows. Therefore, means for fixing the bellows, such as soldering, laser, and welding with an electron beam, have been used.
[0003]
However, in the case of the joining means by soldering, in order to use the flux, after soldering processing, the part must be sufficiently washed with water, and the equipment cost is required to use a laser or electron beam. In addition to this, there is also a drawback of process complexity. On the other hand, it is proposed that the end of the bellows is pressed in a case where the required level of sealing of the fixed portion is relatively low. That is, as shown in FIG. 4, when fixing the end portion of the bellows 42 to the lid 41, the packing 43 is sandwiched between both end portions, and the end portion is wound between the lower mold 44 and the upper mold 45 and is crimped. It has also been proposed (Japanese Patent Laid-Open No. 3-28576).
[0004]
[Problems to be solved by the invention]
In the above-mentioned conventional one, not only the upper and lower split molds are required in the crimping molding, but also another molding tool is required in addition to the curling molding for winding the bellows end, and many molding processes are required. There are drawbacks that require complex and expensive parts.
[0005]
In order to eliminate the above disadvantages, as shown in FIG. 5, the lower surface of the flange portion 51 formed by forming the crest at the end of the bellows 50 with a large diameter is placed on the valve body lower member 52, and the upper surface Has been proposed in which the lower end outer peripheral wall 54 of the valve body upper member 53 is fixed to the outer peripheral step portion of the valve body lower member 52 by caulking 55. As shown in the figure, it has been found that the upper surface of the sandwiching portion of the bellows is pressed and deformed by pressing by the valve body upper member 53, and the elastic modulus changes and the seal becomes uncertain.
[0006]
Moreover, as shown in FIG. 6, the flange part 51 formed by forming the peak part of the end part of the bellows 50 into a large diameter has its lower surface placed on the valve body lower member 52, and the upper surface is the valve body upper member. 53, when the lower end outer peripheral wall 54 of the valve body upper member 53 is fixed to the outer peripheral step portion of the valve body lower member 52 by caulking 55, the lower end outer peripheral wall is placed on the pressing surface 56 of the valve body upper member 53. It has also been proposed to form an annular protrusion 58 at a position spaced from the inner surface 57 of 54, thereby pinching the flange portion 51 of the bellows 50. Although such a fixing means eliminates the problem of the change in elastic modulus due to the deformation of the bellows as described above, as shown in the figure, it warps against the upper member 59 of the bellows peak forming the flange portion 51. 60, resulting in an uncertain seal, and even if a sealing material was applied or placed on the lower surface of the annular protrusion 58, the sealing performance was insufficient.
[0007]
Therefore, an object of the present invention is to provide a bellows end sealing structure that can be manufactured and assembled by simple and inexpensive means, can be reliably sealed, and does not impair the characteristics of the bellows.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention places the lower surface of the flange portion formed by forming the peak portion of the bellows end portion on a large diameter on the valve body lower member, and the upper surface of the flange portion below the valve body upper member. In the sealing structure of the bellows end portion, which is opposed to substantially the entire end face, and the lower end outer peripheral wall of the valve body upper member is caulked and fixed to the step portion of the outer periphery of the valve body lower member , An annular protrusion is formed at a position spaced in the inner diameter direction from the inner surface of the lower end outer peripheral wall of the valve body upper member, and a packing is provided between the upper surface of the flange portion of the bellows and the lower end surface of the valve body upper member, An annular recess is provided between the annular protrusion and the inner surface of the lower end outer peripheral wall of the valve body upper member .
[0009]
Since the present invention is configured as described above, when assembling the bellows, a flange portion at the end of the bellows is placed on the upper surface of the lower member of the valve body, a packing is placed thereon, and a valve is mounted from above. The body upper member is covered, and the lower end outer peripheral wall of the valve upper member is crimped and fixed to the step on the outer periphery of the valve lower member. In this assembled state, when the packing is pressed by the lower end surface of the valve body upper member, the annular protrusion of the valve body upper member bites into the packing, and a reliable seal is performed. At this time, the deformed portion of the packing caused by being locally pressed by the annular protrusion fits into the relief portion formed in the separated portion between the annular protrusion and the lower end surface of the valve body upper member, and the bellows due to abnormal deformation of the packing The deformation action is prevented and the sealing performance is enhanced. In addition, since there is some relief at the lower end surfaces of the packing and the valve body upper member, the upper member of the bellows crest is not warped, and the protrusion is reliably sealed. Further, since the packing is substantially the same as the diameter of the flange portion of the bellows, when the flange portion receives pressure is deformed to the outside of the bellows, received as soft stopper, when trying to get rise to a larger deformation, packing the valve It hits the lower end surface of the upper body member and prevents further deformation.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a valve device to which the present invention is applied. A valve body lower member 1 is provided with a first opening 2 and a second opening 3, and a spherical valve pressed by a spring against a valve seat 4 formed therebetween. 5 is provided so that contact / separation is possible. A rod 6 abuts on the upper part of the spherical valve 5, and the rod 6 extends upward through the sliding hole 7 of the lower member of the valve body and is pressed downward by a spring 8. 11, the spherical valve 5 is pressed from above. The upper end portion of the spring 8 is received by an adjustment member 14 fixed to the valve body upper member 13 via the spherical body 12, and the spring force can be adjusted by moving the adjustment member 14 up and down.
[0011]
As shown in FIG. 2, the bellows 10 has a flange portion 16 formed by increasing the diameter of the peak portion 15 at an upper portion thereof, and an upper member 17 of the bellows forming the flange portion 16. An annular rising portion 18 is formed at the inner end portion. On the bottom surface 20 of the bellows 10, a stopper 11 for receiving the rod 6 as described above is fixed.
[0012]
The upper flange portion 16 of the upper portion of the bellows 10 thus configured is as shown in FIG. 1 and as shown in FIG. A packing 22 made of an elastic material is placed on the upper member 17 of the flange portion 16. An annular protrusion 26 of the valve body upper member 13 abuts on the upper surface thereof, and an outer peripheral wall 24 formed on the outer periphery of the lower end surface 23 covers the upper end outer periphery of the valve body lower member 1 and further extends downward to form the valve body lower member. 1 is fixed by caulking to a step 25 formed on the outer periphery.
[0013]
An annular protrusion 26 is formed on the lower end surface 23 of the valve body upper member 13 with a space from the inner surface of the outer peripheral wall 24. The annular protrusion 26 is set lower than the thickness of the packing 22. Further, the packing 22 is formed to have substantially the same size as the lower end surface 23 of the valve body upper member 13, and is opposed to the entire upper surface of the upper member 17 of the flange portion 16 of the bellows 10. A cylindrical rising portion 18 is provided at the inner peripheral end of the upper member 17 of the bellows. Since the annular protrusion 26 is spaced from the inner surface of the outer peripheral wall 24, an annular recess 28 is formed therebetween.
[0014]
In the valve body configured as described above, when assembling as described above, when the outer peripheral wall 24 of the valve body upper member 13 is caulked to the step portion 25 of the valve body lower member 1, When the upper surface of the packing 22 is strongly pressed by the end surface 23, the annular protrusion 26 formed on the lower end surface 23 enters the packing 22. At this time, the portion of the packing 22 into which the annular protrusion 26 bites is deformed and moved on the outer peripheral side and the inner peripheral side, but the portion deformed and moved on the outer peripheral side enters the annular recess 28 and deformed and moved on the inner peripheral side. The part to move moves to the free end side. For this reason, it is reliably sealed by the annular protrusion 26.
[0015]
In such an assembled and fixed state of the valve body, the upper surface of the upper member 17 of the bellows 10 is substantially uniformly pressed by the packing 22 so that the bellows is not deformed and the elastic modulus of the bellows does not change. . Further, since the packing 22 is strongly pressed by the lower part of the annular protrusion 26 at the upper part of the bellows 10, the sealing of this part is surely performed.
[0016]
【The invention's effect】
The present invention, since the structure described above, in this assembled state, when packing being pressed by the lower surface of the valve body upper member, the annular projection of the valve body upper member bites into the packing, is possible to perform a reliable seal it can. At this time, the deformed portion of the packing caused by being locally pressed by the annular protrusion fits into the relief portion formed in the separated portion between the annular protrusion and the lower end surface of the valve body upper member, and the bellows due to abnormal deformation of the packing The deformation action of the bellows can be prevented, the change in the elastic modulus of the bellows can be prevented, and the sealing performance can be enhanced. In addition, since the packing is sized so as to face substantially the entire flange surface of the valve body upper member, in the assembled state, the upper surface of the flange portion is uniformly pressed, and the upper member of the bellows crest is warped. The flange portion can be prevented from being deformed by the pressure applied to the bellows without being generated.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an entire valve element to which the present invention is applied.
FIG. 2 is a cross-sectional view of a bellows used in the present invention.
FIG. 3 is an enlarged cross-sectional view of a bellows sealing portion according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view of a conventional bellows sealing portion.
FIG. 5 is a cross-sectional view of another conventional bellows sealing portion.
FIG. 6 is a cross-sectional view of still another conventional bellows sealing portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve body lower member 2 1st opening 3 2nd opening 4 Valve seat 5 Spherical valve 6 Rod 7 Sliding hole 8 Spring 10 Bellows 11 Lower pad 12 Sphere 13 Valve body upper member 14 Adjustment member 15 Mountain part 16 Flange part 17 Upper member 18 Standing portion 20 Bottom surface 22 Packing 23 Lower end surface 24 Outer peripheral wall 25 Step portion 26 Annular projection

Claims (1)

The lower surface of the flange portion formed by forming the crest portion of the bellows end portion with a large diameter is placed on the lower member of the valve body, and the upper surface of the flange portion is opposed to substantially the entire lower surface of the upper member of the valve body. In the sealing structure of the bellows end formed by caulking and fixing the lower end outer peripheral wall of the upper member to the stepped portion of the outer periphery of the valve body lower member, the inner surface of the lower end outer peripheral wall of the valve body upper member on the lower end surface of the valve body upper member An annular protrusion is formed at a position spaced from the inner diameter direction from the flange, a packing is provided between the upper surface of the flange portion of the bellows and the lower end surface of the valve body upper member, and the outer periphery of the lower end of the annular protrusion and the valve body upper member A bellows end sealing structure , wherein an annular recess is provided between the inner surface of the wall .

Images