JP2004241373A - Vacuum valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum valve capable of simply mounting a guide member guiding and supporting a movable rod to a valve main body, with a structure improved so as to secure a stable connection strength between an end plate and the guiding member in a state that the valve main body is assembled. <P>SOLUTION: A movable contact piece and a fixed contact piece are assembled in an airtight container with end plates joined to both ends of an insulation cylinder to form a construction of airtightly drawing out the movable rod through a bellows, and a guide 6 made of resin having a flange guiding the movable rod in axial direction is inserted into a hole 2a opened on the end plates 2 of the valve main body. The guide 6 is to be inserted into and jointed to the end plates 2 through a bayonet joint, and as a jointing structure, engaging protrusions 6c are formed at the peripheral surface of a cylindrical part 6a of the guide 6 while securing a gap g same as a thickness d of the end plate 2 between a flange part 6b and the engaging protrusions, and notched grooves 2b are formed on the periphery of the hole on the base plate so as to face the engaging protrusions. The cylindrical part 6a of the guide is inserted into the hole on the end plate 2 by fitting the engaging protrusions 6c with the notched grooves 2b and fixed by rotating in a peripheral direction. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an assembly structure of a vacuum valve applied to a vacuum circuit breaker or a vacuum switch.

As is well known, the vacuum circuit breaker and the vacuum switch are equipped with a vacuum valve of a current cutoff part, and the structure of the vacuum valve is fixed to an airtight container having end plates joined to both ends of an insulating cylinder, and a movable contact. After the armature is mounted, a guide member is attached to a hole opened at the center of the end plate, and the movable rod of the movable contact is guided in the axial direction through the guide member to be drawn out (for example, And Patent Document 1).
Next, the configuration of a conventional vacuum valve is shown in FIGS. In the figure, 1 is an insulating cylinder of the valve body, 2 and 3 are metal end plates (flanges) hermetically joined to both ends of the insulating cylinder 1, 4 is a movable contact, 5 is a fixed contact, 4a is a movable contact, 5a is a fixed contact, 6 is a guide which is inserted and supported in the central opening hole of the end plate 2 to guide and support the movable rod of the movable contact 5 so as to be slidable, and 7 is between the end plate 2 and the movable contact 4. The bellows bridged, 7 a is a bellows cover connected to the rod of the movable contact 4, 8 is an arc shield built in the insulating cylinder 1, and 9 is a cap for fixing the guide 6.

In the above configuration, the movable contact 4 is pulled out of the valve body through the bellows 7 in an airtight manner, and is connected to an opening / closing drive mechanism (not shown). The operation of opening and closing the contact of the vacuum valve is well known, and the description thereof is omitted here.
The guide 6 is a resin molded product provided with a flange 6b at the tip of a cylindrical portion 6a serving as a bearing for a movable rod. The cylindrical portion 6a is inserted into an opening of the end plate 2 as shown in FIG. The portion 6b is fixed on the upper surface of the end plate 2 as described below. That is, in the configuration shown in FIG. 5, a guide that passes through the rod of the movable contact 4 in a state where the components of the end plates 2 and 3, the movable contact 4, the fixed contact, and the bellows 7 are attached to the insulating cylinder 1. 6, the cylindrical portion 6a is inserted into the shaft hole of the end plate 2, the flange portion 6b is overlapped with the end plate 1, and the both are fixed with an adhesive. On the other hand, in the configuration of FIG. 6, the peripheral edge of the metal cap 9 covering the flange 6b of the guide 6 is spot-welded or bonded to the end plate 1 to indirectly fix the guide 6. In addition, there is a configuration in which the guide 6 is screwed to the end plate 2.

On the other hand, as a fixing means of the guide 6 fitted to the end plate 2, a flexible member protruding from the cylindrical portion of the guide to the outer peripheral side without welding or screwing the adhesive and the cap as in the above configuration is used. There is also known an assembly structure in which a dovetail is formed and the engaging claw is engaged with and fixed to the end plate in a state where the guide is press-fitted into a hole of the end plate. (For example, see Patent Document 2).
JP-A-6-309998 (FIGS. 1, 7, and 8) JP-A-7-272600 (FIGS. 1 to 6)

By the way, the above-mentioned conventional vacuum valve has the following problems.
That is, in the configuration of FIGS. 9 and 10, the guide 6 assembled to the valve body is bonded to the end plate 2 or is welded and joined via the metal cap 9, so that the number of assembly steps and time are reduced. This increases costs.
Further, the assembly structure disclosed in Patent Document 2 has an advantage that the guide member can be easily assembled as compared with the above-described structure, but the coupling strength between the end plate and the guide member in the assembled state of the valve body. When the thickness of the engaging claw is increased so as to secure the engaging claw, the flexibility of the engaging claw is reduced, and the press-fitting operation of the guide member into the end plate becomes difficult. If the thickness is made thinner to make it easier to bend, the strength of the engaging claw decreases, and the engaging claw comes off the end plate when an axial load is repeatedly applied to the guide member with the opening and closing operation of the vacuum valve. Or breakage, which lowers the reliability.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to solve the above-described problems, to easily attach a guide member for guiding and supporting a movable rod to a valve body, and to assemble the valve body in an assembled state. An object of the present invention is to provide a vacuum valve having an improved assembly structure so that a stable coupling strength can be secured between an end plate and a guide member.

To achieve the above object, according to the present invention, a movable contact and a fixed contact are assembled in an airtight container having end plates joined to both ends of an insulating cylinder, and a movable rod of the movable contact is hermetically sealed via a bellows. And a resin-made guide member with a flange for guiding a movable rod of a fixed contact in an axial direction into a hole opened in one end plate of the valve body. In the one that is attached,
In the first invention, the guide member is inserted and connected to an end plate via a bayonet joint (claim 1), and the bayonet joint is specifically configured in the following manner.
(1) As a bayonet joint, an engagement projection is provided on the peripheral surface of the cylindrical portion of the guide member, leaving a gap corresponding to the thickness of the end plate between the flange and the guide member. Correspondingly, a notch groove is formed in the peripheral edge of the hole opened in the end plate, the engagement protrusion is aligned with the notch groove of the end plate, the cylindrical portion of the guide member is inserted and the guide member is moved in the circumferential direction. Then, the engaging protrusion is engaged with the back surface of the end plate and fixed (claim 2).

(2) The strength of the engagement projection of (1) is improved as a rib-shaped projection extending in the axial direction of the cylindrical portion (claim 3).
(3) As a means for preventing the bayonet joint from loosening and the guide member from rotating, a fitting-type detent connecting portion is provided between the guide member and the end plate (claim 4). The connecting portion is specifically configured in the following manner.
(a) A dowel-shaped convex portion is formed on the end surface of the engaging projection formed on the guide member as a detent connecting portion, and a fitting hole for fitting the convex portion is formed on the end plate. Then, the dowel-shaped projection is fitted into the engagement hole of the end plate to prevent rotation (claim 5).
(b) The dowel-shaped projection is formed on the back side of the flange of the guide member as a detent connection part, and the dowel-shaped projection is fitted into the engagement hole of the end plate at the mounting position of the guide member. To prevent rotation (claim 6).

(c) As a detent connecting portion, a trapezoidal projection is provided on the flange of the guide member to fit into the notch groove of the end plate, and the trapezoidal projection is cut out of the end plate at the mounting position of the guide member. The detent is fitted by fitting into the groove (claim 7).
On the other hand, in the second invention of the present invention, a gap corresponding to the thickness of the end plate is secured between the flange of the guide member and the peripheral surface of the cylindrical portion of the guide member as the coupling means of the guide member. A rib-shaped engaging projection with an L-shaped cross section extending in the axial direction is formed upright, and the guide member is press-fitted into the opening hole of the end plate while bending the rib-shaped projection in the radial direction. Then, the projection restored to the original shape is brought into contact with the plate surface of the end plate to lock and fix the guide member (claim 8).
Further, in order to secure a sufficient allowance for the rib-shaped engagement projection, a concave groove (claim 9) or a notch hole (claim 9) serving as an escape of the engagement projection is formed on the peripheral surface of the cylindrical portion of the guide member. Item 10) shall be formed.

According to the configuration of the present invention described above, the following effects can be obtained.
(1) According to the first invention employing a bayonet joint as a means for fixing the guide member to the end plate, a time-consuming technique such as adhesive or welding is required when assembling the guide member to the valve body. Instead, the guide member can be easily inserted and fixed to the end plate only by inserting and turning the guide member. In addition, since the guide member can be removed even after being assembled to the valve body, it is possible to easily cope with replacement of the guide member as necessary.
In addition, the mechanical strength of the guide member is enhanced by making the engagement protrusion of the guide member constituting the bayonet joint a rib-shaped protrusion, and further by providing a detent joint between the guide member and the end plate, The guide member can be prevented from rotating by preventing the bayonet joint from loosening, thereby improving the reliability of the product.

  (2) According to the second aspect of the present invention, in which the guide member is fixed to the end plate, a tapered rib-shaped engagement projection having an L-shaped cross section is formed on the peripheral surface of the cylindrical portion of the guide member. In the process of press-fitting into the opening hole of the plate, the rib-shaped engaging projection having an L-shaped cross section is crushed into a cross-sectional shape of "H" and bent so as to be deformed. The guide member can be locked and fixed to the valve body by abutting the engagement projection restored to the shape of the above on the back surface of the end plate. Moreover, since the cross-sectional shape of the engaging projection is L-shaped, a large bending rigidity can be obtained in the restored state while securing sufficient flexibility, and thus the cylindrical portion of the guide is brought together with the opening and closing operation of the vacuum valve. Even if a load is repeatedly applied in the axial direction, there is no possibility that the engaging projections will buckle or break, and the durability and reliability are improved.

  Next, embodiments of the present invention will be described based on the illustrated examples described below. In the drawings of each embodiment, members corresponding to those in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 is an explanatory view of a connecting structure of a guide member and an end plate according to claims 1, 2, 4, and 5 of the present invention, and an assembling procedure thereof. In this embodiment, the end plate 2 and a guide member to be fitted and inserted into a shaft hole 2a opened at the center of the end plate are connected via a bayonet joint as described below. That is, with respect to the guide 6 of the resin molded product composed of the cylindrical portion 6a and the flange portion 6b, the cylindrical portion 6a is formed with engaging projections 6c distributed at four positions on the peripheral surface. Notch grooves 2b are formed in the peripheral edge of the shaft hole 2a at four locations on the end plate 2 corresponding to the projections 6c, respectively.
Here, the engaging projection 6c secures a gap g corresponding to the thickness d of the end plate 2 with the flange 6b and protrudes from the peripheral surface of the cylindrical portion 6a. Further, a dowel-shaped convex portion (small protrusion) 6d is formed on the rear end surface facing the back surface of the end plate 2. Reference numeral 6e denotes a hole formed by a core inserted into a molding die so as to form the engaging projection 6c.

On the other hand, the notch groove 2b formed in the peripheral edge of the shaft hole of the end plate 2 corresponds to the cross-sectional shape of the engaging projection 6c, and is further displaced in the circumferential direction with the notch groove 2b to form the dowel-shaped protrusion. An engagement hole 2c (through hole or depression) that fits with the portion 6d is formed.
In the above configuration, in order to attach the guide 6 to the end plate 2, the engagement protrusion 6 a is aligned with the notch groove 2 b of the end plate 2, and the cylindrical portion 6 a of the guide 6 is moved from the direction of arrow A to When the flange 6b is inserted into the hole 2a and the flange 6b overlaps the rear surface of the end plate 2, it is turned in the direction of arrow B in the drawing to fit the dowel-shaped protrusion 6d into the engagement hole 2c of the end plate 2 and locked at that position. Fix it.
Thus, when the guide 6 is assembled, the end plate 2 is sandwiched between the engagement protrusion 6c and the flange portion 6b to be fixed in the axial direction, and the dowel-shaped protrusion 6d is formed in the engagement hole of the end plate 2. It fits into 2c and is locked and stopped.

  When the guide 6 is to be detached in the assembled state of the valve body due to the necessity of replacing parts, the guide 6 is turned in the direction opposite to the arrow B by applying an external force so that the dowel-shaped projection 6d and the engagement hole 2c Is disengaged, and then the engaging protrusion 6c is positioned in the notch groove 2b and pulled out in the direction opposite to the arrow A, so that the engaging protrusion 6c slips through the notch groove 2b to remove the guide 6. be able to.

FIG. 2 shows a modification of the first embodiment corresponding to claim 6 of the present invention. That is, in the first embodiment, the dowel-shaped protrusion 6d of the guide 6 is formed on the end surface of the engagement protrusion 6c, whereas in this embodiment, the dowel-shaped dowel-shaped protrusion 6d is formed on the back surface of the flange 6b. An engagement hole 2b is formed in the end plate 2 on the side of the notch groove 2b so as to correspond to the dowel-shaped projection 6d.
The mounting and dismounting operation of the guide 6 according to the above configuration is the same as that in the first embodiment. However, in this embodiment, since the dowel-shaped convex portion 6d is formed on the thick flange portion 6b, the guide is compared with the configuration in FIG. 6, the strength of the detent fixing is improved.

FIG. 3 shows an application example corresponding to claim 7 of the present invention. That is, in this embodiment, a trapezoidal projection which is displaced in the circumferential direction with the engagement projection 6c on the inner surface side of the flange portion 6b and fits into the notch groove 2b of the end plate 2 as an engagement projection for preventing the guide 6 from rotating. A portion 6f is formed.
In this configuration, the notch groove 2b of the end plate 2 is used to engage the trapezoidal convex portion 6f of the guide 6 to prevent rotation, so that the end plate 2 has a dowel shape as in the first and second embodiments. There is no need to machine the engaging hole 2c for the protrusion 6d.

FIG. 4 shows an embodiment corresponding to claim 3 of the present invention based on the configuration of the third embodiment. The engagement projection formed on the peripheral surface of the cylindrical portion 6a of the guide 6 has: As shown, it is formed as a rib-shaped protrusion 6g extending in the axial direction. The operation for attaching and detaching the guide 6 is the same as in FIG.
In this embodiment, since the engagement projection of the guide 6 is the rib-shaped projection 6g, the rib-shaped projection serves as a reinforcing rib, and the strength of the guide 6 is increased. The rib-shaped protrusion 6g can be applied to the embodiment in place of the engagement protrusion 6c in each of the first to third embodiments.

Next, an embodiment of the second invention corresponding to claims 8 to 10 of the present invention will be described with reference to FIGS.
First, in FIGS. 5 (a) to 5 (d), the cylindrical portion 6a of the guide 6 (resin molded product) is divided into four portions on the peripheral surface, and is a tapered rib which stands in an L-shaped cross section and extends in the axial direction. An engagement protrusion 6h is integrally formed. The rib-shaped engagement protrusion 6h leaves a gap g corresponding to the plate thickness d of the end plate 2 between the front end surface and the surface of the flange portion 6b of the guide 6, and has a cylindrical portion 6a at the rear end side. A tapered surface 6h-1 inclined backward so as to converge on the peripheral surface is formed. Reference numeral 6h-2 denotes a gap remaining between the peripheral surface of the protrusion protruding in an L-shape along the longitudinal direction of the rib-like protrusion 6h and the cylindrical portion 6a. In order to mold the rib-shaped engaging projections 6h on the peripheral surface of the cylindrical portion of the guide 6, a core corresponding to the gap 6h-2 is inserted into the cavity of the molding die from the side of the flange 6b. To be generated. As a result, a square hole 6e remains on the flange 6b of the guide 6 at the mark where the core has been inserted.

To assemble the guide 6 with the end plate 2 of the vacuum valve in the above-described configuration, the cylindrical portion 6a of the guide 6 is fitted together with the rib-shaped engagement protrusion 6h while applying a pressing force to the opening hole of the end plate 2. I do. In this pushing process, the tapered surface 6h-1 of the rib-shaped engaging projection 6h is handled by the inner peripheral edge of the hole of the end plate 2, and the engaging projection 6h is moved by the reaction force between the inner diameter of the hole of the end plate 2 and the cylindrical portion of the guide 6. The L-shaped cross section is deformed so as to be crushed into a flat “H” -shaped cross section due to a dimensional difference from the diameter, and is bent in the radial direction. In this state, when the guide 6 is further pushed to a position where the flange portion 6b overlaps the plate surface of the end plate 2, the rib-shaped engagement protrusion 6h passes through the opening hole of the end plate 2 and returns to its original shape (L-shaped cross section). And the protrusion having the L-shaped cross section protrudes to the outer peripheral side of the hole of the end plate 2. As a result, the guide 6 is locked and fixed to the end plate 2 in the axial direction as in the first embodiment.
As can be seen from the above description, according to this embodiment, the notch groove, the dowel-shaped convex portion for preventing rotation, and the engagement hole of the flange portion 6b can be omitted as compared with the first embodiment, and the guide 6 can be omitted. In addition to simplifying the molding die, assembly to the valve body can be easily performed by one-touch operation.

Next, based on the above-described structure, FIGS. 6 to 8 show a structure of an applied embodiment in which the bending allowance for the rib-shaped engaging protrusion 6h is increased and the flexibility is improved.
First, in the embodiment shown in FIGS. 6 (a) to 6 (d), as shown in FIG. 6 (d), the cylindrical portion 6a of the guide 6 has a portion corresponding to the rib-shaped engaging projection 6h on the outer peripheral surface. The concave groove 6a-1 is formed so as to enlarge the bending allowance in the radial direction of the engaging protrusion 6h having an L-shaped cross section (the arrow in the figure indicates the bending direction of the engaging protrusion 6h). The other structure and the procedure for assembling the valve body are the same as those in the embodiment of FIG.
In the embodiment shown in FIGS. 7 (a) to 7 (d), a notch 6a-2 penetrating the cylindrical portion 6a in the radial direction is formed instead of the concave groove 6a-1 in FIG. We are trying to expand further.

  Further, in the embodiment shown in FIGS. 8 (a) to 8 (d), as can be seen from FIG. 8 (d), the rib-shaped engaging projection 6h formed upright from the cylindrical portion 6a to have an L-shaped cross section is formed on the peripheral back side. The gap 8h-2 is formed over the entire length in the longitudinal direction so as to open at the front and rear ends of the protrusion. As a result, the rib-shaped engagement protrusion 6h is easily bent in the process of press-fitting the guide 6 into the opening hole of the end plate 2 (the arrow in the drawing indicates the bending direction), and a large force is not required. The guide 6 can be assembled.

FIG. 2 is an exploded perspective view illustrating a connection structure between a guide member and an end plate according to the first embodiment of the present invention and an assembling operation thereof. FIG. 6 is an exploded perspective view illustrating a coupling structure between a guide member and an end plate according to a second embodiment of the present invention. FIG. 11 is an exploded perspective view illustrating a coupling structure between a guide member and an end plate according to a third embodiment of the present invention. FIG. 11 is an exploded perspective view illustrating a coupling structure between a guide member and an end plate according to a fourth embodiment of the present invention. FIG. 13 is an explanatory diagram of a coupling structure between a guide member and an end plate according to a fifth embodiment of the present invention, wherein (a) is a plan view of the guide member, (b) is a side view of an assembled state in which the guide member is coupled to the end plate, (c) is a partially cutaway perspective view of the guide member, and (d) is an enlarged perspective view of the rib-shaped engagement protrusion. 5 (a) is a plan view of a guide member, FIG. 5 (b) is a side view of an assembled state where the guide member is connected to an end plate, and FIG. (D) is a partial cross-sectional view along the circumferential direction of the cylindrical portion of the guide having the rib-shaped engaging projections formed upright. 6 (a) is a plan view of a guide member, FIG. 5 (b) is a side view of an assembled state where the guide member is connected to an end plate, FIG. ) Is a partially cutaway perspective view of the guide member, and (d) is a partial cross-sectional view along the circumferential direction of the cylindrical portion of the guide having the rib-shaped engagement projections formed upright. 5A and 5B are explanatory views of still another applied embodiment based on the structure of FIG. 5, wherein FIG. 5A is a plan view of a guide member, FIG. 5B is a side view of an assembled state where the guide member is connected to an end plate, and FIG. Partially cutaway perspective view of the guide member, (d) is an external perspective view of a rib-shaped engaging projection formed upright on the cylindrical portion of the guide. Configuration sectional view showing the assembly structure of a conventional vacuum valve Sectional drawing showing the main part assembly structure of the conventional example different from FIG.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Insulating cylinder 2, 3 End plate 2a Shaft hole 2b Notch groove 2c Engagement hole 4 Movable contact 5 Fixed contact 6 Guide 6a Cylindrical part 6b Flange part 6c Engagement projection 6d Dowel-shaped convex part 6f Trapezoidal convex part 6g Rib-shaped protrusion 6h Rib-shaped engagement protrusion 6h-1 Tapered surface

Claims (10)

A movable valve and a fixed contact are assembled in an airtight container having end plates joined to both ends of an insulating cylinder, and the movable valve is a vacuum valve having a structure in which a movable rod is pulled out airtight through a bellows. In one end plate, a resin flanged guide member for guiding the movable rod of the movable contact in the axial direction into a hole opened in the end plate is inserted and mounted.
A vacuum valve, wherein the guide member is fitted and connected to a shaft hole of an end plate via a bayonet joint. 2. The vacuum valve according to claim 1, wherein a gap corresponding to the thickness of the end plate is secured between the flange of the guide member and the flange of the guide member on the peripheral surface of the cylindrical portion of the guide member as the bayonet joint. And a notch groove is formed in the peripheral edge of the shaft hole of the end plate corresponding to the engagement protrusion, and the engagement protrusion of the guide member is aligned with the notch groove so that the cylindrical portion of the guide member is attached to the end plate. A vacuum valve, wherein a guide member is turned in the circumferential direction and locked and fixed after being inserted into an opening hole. 3. The vacuum valve according to claim 2, wherein the engaging projection is a rib-shaped projection extending in an axial direction of the cylindrical portion. The vacuum valve according to any one of claims 1 to 3, wherein a fitting-type detent connection portion is provided between the guide member and the end plate as a means for preventing the bayonet joint from loosening and the detent from rotating the guide member. A vacuum valve, characterized in that: 5. The vacuum valve according to claim 4, wherein a dowel-shaped projection is fitted on the end face of the projection of the guide member as the rotation preventing coupling part, and the projection is fitted on the end plate at an assembly position of the valve member. A vacuum valve having a hole formed therein. 5. The vacuum valve according to claim 4, wherein the detent-shaped connecting portion has a dowel-shaped convex portion on a flange portion of the guide member, and an engagement hole with which the convex portion fits at an assembly position of the valve member on an end plate. 6. A vacuum valve characterized by being formed. 5. The vacuum valve according to claim 4, wherein a trapezoidal convex portion is provided on the flange of the guide member as the rotation preventing coupling portion so as to fit into the notch groove of the end plate at the mounting position of the guide member. And vacuum valve. A movable valve and a fixed contact are assembled to an airtight container having end plates joined to both ends of an insulating cylinder, and the movable rod of the movable contact is pulled out airtight through a bellows. In one in which a guide member with a resin flange for guiding the movable rod of the movable contact in the axial direction is fitted and mounted in a hole opened in one end plate,
A tapered rib-shaped engaging projection having an L-shaped cross section extending in the axial direction while securing a gap corresponding to the thickness of the end plate between the peripheral surface of the cylindrical portion of the guide member and the flange of the guide member. At the position where the guide member is press-fitted into the opening hole of the end plate while bending the engagement protrusion in the radial direction, the engagement protrusion restored to the original shape is abutted against the back surface of the end plate. A vacuum valve, wherein the guide member is locked and fixed. 9. The vacuum valve according to claim 8, wherein a concave groove is formed on the peripheral surface of the cylindrical portion of the guide member so as to secure a bending allowance of the engaging protrusion, corresponding to the engaging protrusion having an L-shaped cross section. valve. 9. The vacuum valve according to claim 8, wherein a notch hole is formed in the peripheral surface of the cylindrical portion of the guide member to secure a bending allowance of the engaging projection, corresponding to the engaging projection having an L-shaped cross section. Vacuum valve.

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