JPS6212430B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a cam lock type flange joint, which is improved so that no bending stress is generated on the shaft supporting the lock rotating cam when the joint is locked.

A cam lock type flange joint is a joint that uses a cam to tightly fix flanges attached to the ends of pipes, etc. Compared to normal flange joints, there is no need to tighten bolts. It has the advantage of being able to connect tubes easily, quickly and reliably.

First, the structure and problems of a conventional cam-lock type flange joint will be explained with reference to FIGS. 1 and 2.

The reference numeral 1 in the figure is a flange fixed to the end of a suitable pipe material 2 by welding or the like, and as shown in FIG. are formed at equal intervals. The cam support portion 3 is constructed by integrally extending an ear portion 4 that projects slightly radially outward from the reference outer circle of the flange 1. 5 is a stepped screw for rotatably supporting the cam body 6, and has a head 7, a large diameter shaft portion 8 for supporting the cam body 6, and a male threaded end portion 9; A through hole 1 of the cam body 6 is provided in the diameter shaft portion 8.
The cam body 6 is rotatably supported relative to the ear part 4 by rotatably fitting the cam body 6 into the ear part 4 and by screwing the tip male thread part 9 into the female thread 11 formed in the ear part 4.

On the other hand, the cam body 6, as shown in FIG. It has a shape in side view such that a collar-shaped cam portion 13 extends in the radial direction from a boss portion 12 having a hole 10. The flange side surface 13a of the brim-shaped cam portion 13 is the outer surface 14a of the mating flange 14.
A cam surface that functions to come into contact with and press the flange 14 against the flange 14, and has an inclined surface inclined in the circumferential direction. Further, reference numeral 15 indicates the cam body 6
This is a concave groove into which a rod-shaped tool (not shown) for rotating is fitted. Further, a grease nipple 16 is provided on the head 7 of the stepped screw 5, and the grease injected from this is applied to the large diameter shaft portion 8 of the stepped screw 5.
The sliding contact portion between the cam body 6 and the through hole 10 of the cam body 6 is lubricated.

As shown in FIG. 1, when the cam body 6 is positioned so that its notch faces inward, the opposing flange 14 can be moved without interfering with the brim-shaped cam portion 13 of the cam body 6. It is now possible to position them in close contact with the connecting surface 1a of the flange 1.
After positioning the flange 14 on the other side as shown in FIG. 1, when the cam body 6 is rotated in a predetermined direction,
The brim-shaped cam portion 13 comes to overlap the outer surface of the opposing flange 14, and at the same time, the inclined cam surface 13a of this cam portion 13 comes into contact with the outer edge 14a of the opposing flange 14, causing further rotation. Due to the slope effect of the cam surface 13a, the mating flange 14 is pressed against the flange 1 with a strong force, and the flange 1 and the mating flange 14 are tightly fixed to each other and the pipes are connected.

If it is desired to remove the mating flange 14, it is sufficient to simply rotate the cam body 6 in the opposite direction to that described above and position it so that its notch faces inward, as shown in FIG.

By the way, in the conventional cam lock type flange joint having the structure as described above, when the cam lock is acting, the cam contact part and the shaft 8 that supports the cam body 6 are biased, so that the cam surface 13a is Due to the reaction force pressing the flange 14, a large bending moment acts on the shaft 8, that is, the stepped screw 5. Therefore, in order to tightly fix the mating flange 14 to the flange 1 with sufficient force, it is necessary to use a sufficiently thick stepped screw that can withstand the bending stress caused by the bending moment. As the whole becomes larger, the weight inevitably increases, and there arises a problem that handling is inconvenient. Furthermore, there is also the problem that the life of the support portion of the cam body is generally short.

The present invention was devised under the above circumstances, and its purpose is to generate only tensile stress and no bending stress on the shaft that supports the cam body when the cam is locked. To provide a cam lock type flange joint in which a shaft supporting a cam body can be made much thinner than conventional ones, and the entire cam lock mechanism can be made lighter and smaller.

In order to achieve such an objective, the present invention:
The following technical measures have been taken:

That is, a cam body having a predetermined cam surface is rotatably supported on a flange, and when a mating flange is stacked on this flange and the cam body is rotated, the cam surface presses the mating flange against the flange. In the cam-lock type flange joint, the shaft with the cam body attached to the head is inserted into the shaft support hole provided in the cam support part provided on the periphery of the flange so that there is some play in the shaft support hole. At the same time, a large diameter portion is provided at the end of this shaft to prevent the shaft from coming out of the shaft support hole toward the head side, and the abutment surfaces of the large diameter portion and the cam support portion are made to face each other. It has a spherical shape that makes sliding contact with the surface.

As mentioned above, there is a slight gap between the shaft supporting the cam body on the head and the shaft support hole of the cam support part into which it is inserted, and the size of the cam support part and the end of the shaft is large. By making the abutting surfaces with the diameter part into a spherical shape that makes surface sliding contact, the above-mentioned shaft basically has the following properties:
It is possible to swing within the shaft support hole with the center of the sphere, which is a part of the spherical surface, as the center of swing. As a result, even if a force is applied to the shaft through the cam body during locking, this force is avoided by the shaft elastically extending and swinging, and the cam body bends the mating flange. The reaction force of the pressing force is finally supported by the cam support portion as a tensile force of the shaft.

As a result, in the cam lock type flange joint of the present invention, the shaft supporting the cam body can be made relatively thin considering only the tensile force. This allows the entire cam lock mechanism to be made more compact, reducing weight and reducing material costs. Furthermore, since no bending force is applied to the shaft supporting the cam body, problems such as bending of this shaft will not occur, and constant performance can be maintained over a long period of time.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

3 to 6 show a first embodiment of the invention. In this example, in addition to the basic structure of the present invention, in which the shaft supporting the cam is slightly oscillated around a predetermined oscillation center inside its shaft support hole, This is an example in which the supported cam body is also allowed to play with respect to this shaft, thereby further enhancing the effect of the present invention that no bending force is applied from the cam body to the shaft.

As shown, the cam lock mechanism 20
The flange 21 with the flange 21 has three cam support portions 22 formed at equal intervals on its peripheral edge.
This cam support portion 22 can be formed by integrally extending an ear portion 23 projecting outward from the reference outer diameter circle of the flange 21, as in the conventional example shown in FIGS. 1 and 2. . Each ear part 23
A boss 25 having a shaft support hole 24 is formed in the
The cam body 32 supports the shaft 2 supported in the shaft support hole 24.
7 is rotatably supported.

In the present invention, the inner diameter of the shaft support hole 24 is made slightly larger than the outer diameter of the shaft 27 inserted therein, and the head 28 (left side in FIG. 4) of the shaft 27 is basically able to swing. At the same time, it is irremovably supported.

In order to do this, in the illustrated example, as shown in FIG. 4, the abutment surfaces 29a, 25a between the large diameter nut 29 screwed onto the right end of the shaft 27 in FIG. 4 and the right end of the boss 25 are shown. are formed by making them part of a spherical surface that is in sliding contact with each other and has the same center. In the case of the example shown in FIG. 4, the nut abutment surface 29a is a convex spherical surface, and the boss abutment surface 25
a is a concave spherical surface. As a result, the shaft 27 swings around the center P of the sphere constituting the spherical surface.
It is possible to swing within the range allowed by the gap between the shaft 27 and the shaft support hole 24 of the boss, and the large diameter part of the nut 2
9 is in contact with the end surface of the boss 25, so the shaft 27
will no longer slip out to the left in Figure 4. In addition,
In the illustrated example, the contact surface 25a on the boss 25 side is
Although the washer 31 having a spherical surface is fitted into the end of the boss 25, it goes without saying that a spherical contact surface may be integrally formed at the end of the boss 25. Further, the nut 29 has a pin 30 passing through the nut 29 and the shaft 27, so that
Loose rotation is prevented.

On the other hand, a cam body 32 is inserted into the through hole 33 of the shaft 27 of the boss 25 at a portion located between the head 28 and the boss 25, which protrudes to the left in FIG. Rotatably supported. Note that the inner diameter of the through hole 33 is set to be slightly larger than the outer diameter of the shaft 27. A female conical surface 34 is formed on the left end of the boss 25 in FIG. 4, and a male conical surface 35 that can fit into the female conical surface 34 is formed on the right end of the cam body 32. The right end of the cam body 32 is prevented from shifting in the direction perpendicular to the axis with respect to the left end of the boss 25.
Further, the contact surfaces 28a and 32a between the head 28 of the shaft 27 and the cam body 32 are in surface contact with each other, and
It is composed of a part of a spherical surface having the same center. In addition, in this example, the contact surface 28 of the shaft head 28
a is a convex spherical surface, and the contact surface 32a on the cam body side is a concave spherical surface. In addition, in this example, in order to form the spherical contact surfaces 28a, 32a, washers 40, 41 having spherical seats are attached to the shaft portion adjacent to the head 28 and the through hole 33 of the cam body, respectively. These contact surfaces 28a and 32a are
Of course, it may be formed integrally with the head 28 of the shaft and the cam body 32 itself.

As shown in FIG. 3, the cam body 32 has a shape in plan view that looks like a circle cut out in an arch shape, and as clearly shown in FIG. 1 and 2 on the back surface of the notch-shaped cam portion 36, that is, the surface facing the flange 21.
A cam surface 37 that is inclined in the circumferential direction is formed in the same way as described for the conventional example shown in the figure. Furthermore, a protrusion 38 is formed on the surface of the notch-shaped cam portion 36 to rotate the cam body 32 by hitting it with a hammer (not shown) or the like. Furthermore, what is indicated by the reference numeral 42 in FIG.
This is a grease nipple for feeding grease into the gap formed between the shaft support hole 24 of the boss 25 and the shaft 27 and the through hole 33 of the cam body 32 for lubrication.

Next, the function of the cam lock type flange joint of this example will be explained.

First, as shown in FIG. 3, each cam body 32 is
The notch portion is positioned so as to face inward in the radial direction of the flange 21, and the counterpart flange 39 is positioned so as to overlap the flange 21. Next, when the cam body 32 is rotated in a predetermined direction by hitting the protrusion 38, the brim-shaped cam portion 36 overlaps the peripheral edge of the mating flange 39, and the slanted cam surface 37 presses the upper surface of the other flange, bringing it into tight contact with the flange 21.

FIG. 6 shows the internal state of the cam lock mechanism when the cam lock is engaged.

During cam lock, the cam surface 37 of the cam body 32 acts as a reaction force to the force that strongly presses the mating flange 39 against the flange 21.
A force acts to rotate the point A around the point A in the direction of the arrow B. At this time, since the head 28 of the shaft 27 is engaged with the cam body 32 through its contact surface 28a, several strong tensile forces act on the shaft 27. On the other hand, the shaft 27 and the cam body 32 are connected to the head 28 of the shaft.
Since the spherical contact surfaces 28a and 32a of the cam body 32 can move relative to each other in a rubbing manner while remaining in surface contact with each other, the shaft 27
When the axis 27 elastically extends to a minute length, this axis 27 becomes the sixth
As shown in the figure, the boss 25 and nut 29
The cam body 32 is tilted slightly in the direction of arrow C with respect to the center P of the sphere, which includes the contact surfaces 25a and 29a of the
tilt slightly in the direction. At this time, since the contact surfaces 28a and 32a of the head 28 of the shaft 27 and the cam body 32 are a convex spherical surface and a concave spherical surface having the same center, surface contact is maintained to the last. That is,
At the time of cam lock, the cam body 32 and shaft 27 are
The contact surfaces 28a and 32a move relative to each other so that the contact pressures of the contact surfaces 28a and 32a are averaged, in other words, the contact surfaces 28a and 32a are in the most stable state,
It's about balance. Further, the contact surfaces 25a and 29a of the boss 25 and the nut 29 also slide slightly relative to each other, but they maintain surface contact.

As is clear from FIG. 6, the moment that tries to rotate the cam body 32 in the direction of arrow B when the cam is locked is supported by the shaft 27 as tension, and no force that tries to bend the shaft 27 acts at all. . Therefore, in the cam lock type flange joint of the present invention, since no bending force is applied to the shaft that rotatably supports the cam, this shaft can be made to have a small diameter, which makes the cam lock mechanism compact. Contributes to weight reduction and weight reduction. Furthermore, since the shaft supporting the cam body is unlikely to bend, its lifespan is extended and constant performance can be maintained for a long period of time.

FIG. 7 shows a second embodiment of the cam lock type flange joint of the present invention.

In this example, a spherical surface is formed on the contact surface between the head 28 of the shaft 27 and the end of the cam body, and contact surfaces 25a, 29a between the nut 29, which is the large diameter part of the shaft 27, and the end of the boss 25 are used. By changing the method of forming the spherical surface from that of the first embodiment, the boss 2
The pivot center P of the shaft 27 that pivots within the shaft support hole 24 of No. 5 is changed.

That is, as shown in FIG.
Contact surface 2 between nut 29 and boss 25 at the right end of 7
Contrary to the case shown in FIG. 4, the spherical surfaces formed on 9a and 25a are such that the abutting surface 29a on the nut side is a concave spherical surface and the abutting surface 25a on the boss side is a convex spherical surface, while the head 28 of the shaft The spherical surfaces to be formed on the contact surfaces 28a and 32a with the cam body 32 are the same as those shown in FIG.
a may be a convex spherical surface. Also in this example, no bending force is applied to the shaft supporting the cam body during the cam lock operation, and the same effect as in the first example can be expected.

FIG. 8 shows a third embodiment of the cam-lock type flange joint of the present invention.

In this example, the cam body and the shaft supporting the cam body are integrally formed. That is, the shaft 27 that should support the cam body 32 is a bolt having a square shaft portion 44 at the lower part of the neck of the hexagonal head 28.
The through hole 33 of the cam body 32 having a square hole portion that can fit into the square shaft portion 44 is inserted and fitted into the lower part of the neck. Therefore, the cam body 32 in this example
has integrity with respect to the axis 27. The rest of the configuration of this example is almost the same as the second example shown in FIG. However, the center of swing of the shaft 27, that is, the contact surface 25 of the boss 25 and the nut 29
It is preferable that the center P of the spherical surface formed as a, 29a is located at a position that substantially coincides with the contact portion between the conical surface 35 of the cam body 32 and the conical surface 34 of the boss 25 in the axial direction.

Thus, when the hexagonal head 28 of the shaft 27 is rotated with a tool such as a wrench to rotate the cam body 32 and apply a locking action to the cam body, the cam body 32 presses the mating flange 39 against the flange 21. Due to the force, this cam body 32 tries to rotate in the direction of arrow B in FIG. It balances in a state where it stretches slightly elastically and swings slightly in the direction of arrow C around point A. That is, only a tensile force acts on the shaft, and no bending force acts on it at all. In the example shown in FIG. 8, the cam body 32 and the shaft 27 are fitted together to make it impossible for them to rotate relative to each other. Needless to say, similar effects can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a conventional example, FIG. 2 is a longitudinal sectional view showing a conventional example, FIG. 3 is a side view showing an embodiment of the present invention, and FIG. 4 is a side view showing the conventional example. A vertical sectional view of the example shown, FIG. 5 is a perspective view showing details of the cam body,
Fig. 6 is a longitudinal sectional view for explaining the action;
FIG. 8 is a vertical sectional view showing another embodiment of the present invention.
The figure is a longitudinal sectional view showing still another embodiment of the present invention. 21... flange, 22... cam support part, 24... shaft support hole, 25a... contact surface, 29a... contact surface, 27...
Shaft, 28...Head, 29...Large diameter part (nut), 32
...Cam body, 37...Cam surface, 39...Mating flange.

Claims (1)

[Claims] 1. A cam body having a predetermined cam surface is rotatably supported on a flange, and when a mating flange is stacked on this flange and the cam body is rotated, the cam surface presses the mating flange against the flange. In the cam-lock type flange joint, the shaft with the cam body attached to the head is inserted through the shaft support hole provided in the cam support part provided on the periphery of the flange so that there is some play in the shaft support hole. At the same time, a large diameter portion is provided at the end of this shaft to prevent this shaft from coming out from the shaft support hole toward the head side,
The abutment surfaces of the large diameter portion and the cam support portion are spherical so as to be in sliding contact with each other,
Cam lock type flange joint.