JP2016126090A - Fixing mechanism for rotatable linking part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a fixing mechanism for a rotatable linking part that makes two members fixable with a screw in any desired rotating position to generate frictional force against large rotational force in a configuration that can be easily machined.SOLUTION: A fixing mechanism has a first member 11 and a second member 12 enabled to be fixed with screws in any desired rotating position and two opposing faces 11b and 12b formed around the screw hole of a fastening screw 13 that is thread-inserted between the two members to form frictional faces 11c and 12c in face contact with each other and pressed by the fastening screw. The frictional faces are formed on the outer circumferential parts of the opposing faces to be not greater than the half of the diametric length from the outer circumference of the opposing faces to the circumferential wall of the screw hole, and constitute separated parts that are not brought into contact with each other within the contacting frictional faces even by the tightening of the fastening screw.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fixing mechanism for a rotatable connecting portion in which two members can be screwed around a single axis at an arbitrary rotational position, and in particular, the two members can be stably placed at an arbitrary rotational position with a simple configuration. It is related with the fixing mechanism of the rotatable connection part which can be fixed to and can be easily released.

  Conventionally, for example, by using a support leg member such as a tripod or a stand, a support base member to which a mounting device such as a camera, a lighting device, or various measurement devices is attached is held at a required position in a required posture, or When changing the orientation of the mounting device, etc., between the plurality of connecting struts constituting the support base member, or between the support strut and the support base member such as a camera or a lighting fixture, they can be arbitrarily bent. In general, a fixing mechanism of a rotatable connecting portion called a pan head is incorporated.

  These fixing mechanisms usually include a first member on the fixed side and a second member on the movable side that can be screwed at an arbitrary rotational position around an axis set on the first member. The first and second members have a friction surface directly facing around the axis, or are rotatably joined to each other via a friction member between the friction surfaces, and between the two members on the axis. A tightening screw is screwed into a screw hole provided in the screw, and the two members are fixed at an arbitrary rotational position by tightening or loosening the screw, or are loosened to change the direction between the two members. doing.

  In the fixing mechanism having such a configuration, the rotational force acting between the first and second members is received by the frictional force when tightened with the tightening screw directly between the two members or via the friction member. Although it is desirable to generate a frictional force against a larger rotational force with a simple configuration at the connecting portion of the members, as described above, in the configuration in which the first and second members are simply pressed with the fastening screws, the frictional force is It is difficult to obtain a satisfactory friction force unless the friction coefficient of the surface on which the surface acts and the tightening force of the tightening screw are increased, and it is desirable to generate a larger friction force with a small and simple mechanism. ing.

  Instead of using the frictional force generated between the opposing surfaces of the first and second members, a large number of ridges extending in the radial direction from the center of the axis are mutually attached to each of the opposing surfaces. There is also known a structure in which a meshing portion protruding so as to be meshed is provided, and the meshing position is shifted in the rotational direction so that the first and second members are pressed and fixed by a tightening screw at a multistage rotational position. In this configuration, the two members cannot be fixed at a stepless arbitrary rotational position, and when the tightening screw is loosened to adjust the fixed rotational position of the two members, the meshing portion provided on the facing surface is provided. It is necessary to loosen the tightening screw until each of the ridges can pass over the other ridge, and when a heavy object is supported by a stand etc., not only is there a danger in the adjustment operation, Adjustment operation itself is not always easy .

In addition, in order to increase the frictional force generated between the opposing surfaces, it is conceivable to develop a friction surface having a large friction coefficient, but it is predicted that the development will require a lot of time, labor and cost, and the product As such, it is difficult to provide it at a low price, which is not desirable.
For this reason, it is more desirable to adopt a configuration in which the connecting portion between the two members can generate a frictional force that opposes a large rotational force by a small and easily processable structure and can be easily released.

  Therefore, the present inventor has repeatedly conducted various experiments, trial manufactures, and considerations on the frictional force at the connecting portion, and found that the configuration described in detail below can generate excellent frictional force only by changing the form by machining. The present invention has been made.

  Specifically, first, the general-purpose rotatable connecting portion fixing mechanism as described above is generally opposed to the rotational force acting between the first and second members. The frictional force between the frictional surfaces provided on the surfaces or between the frictional members disposed between the opposing surfaces is used as a resistance (moment) to the rotational movement of the two members. Since the friction surfaces of the first and second members rotate with respect to each other, the frictional force of each minute portion on the friction surface and the center of the minute portion and the screw hole on the entire friction surface. It is considered that the sum is the sum of the products of the distance to the center of the facing surface.

  However, as described above, since the tightening screw is screwed into the screw hole on the central axis of the friction surface and the pair of friction surfaces are strongly pressed, a slight elastic deformation occurs on the friction surfaces, and the first and second Even if the member is made of a high-strength metal material, in reality, the normal force acting on a large number of minute portions between the friction surfaces of the first and second members by the tightening force is total. Is very large on the center side of the friction surface near the screw hole, and becomes relatively small on the peripheral side of the friction surface, and when the tightening force of the tightening screw increases, the periphery of the friction surface There is also a possibility that the side is deformed and the pressing force is almost lost.

  Therefore, the partial frictional force of each part on the friction surface given as the product of the friction coefficient irrelevant to the contact area and the normal force acting on the minute part is increased at a part on the center side of the friction surface. However, it becomes very small at the periphery of the friction surface. That is, as described above, it is given by the sum total of the product of the frictional force of the minute portion of the friction surface and the distance between the minute portion and the center of the screw hole. The resistance (moment) to rotational motion is such that, on the center side near the screw hole of the friction surface, the normal force acting on the friction surface is very large, and the friction force multiplied by the friction coefficient is also large. The distance to the center of the hole is very small, and on the peripheral side far from the screw hole of the friction surface, the distance to the center of the screw hole is large, but the normal force acting on the friction surface is very high. Therefore, the frictional force acting as a resistance (moment) to the relative rotational motion of the first and second members is very small. To things That.

In response to such a problem, the present inventor tightens a pair of friction surfaces by screwing a tightening screw on the central axis of the opposing surfaces of the first and second members, thereby acting on the opposing surfaces. Since the force concentrates on the center side of the opposing surface and does not effectively act on the suppression of the relative rotation of the friction surface, it is confirmed experimentally, and based on that knowledge, When the opposing surfaces of the two members are pressed only at their peripheral portions, the normal drag acting on the central side of the opposing surfaces is concentrated on the peripheral portions of the opposing surfaces, and the frictional force is reduced. It was confirmed that it can be used effectively for the increase.
However, if the friction surface is formed only in a portion that is extremely close to the peripheral side of the facing surface, a large tightening force of the tightening screw is concentrated per unit area in the small area portion. Therefore, there is a possibility that a part of the second member may be damaged, and therefore, the extent to which the friction surface can be concentrated on the peripheral side of the opposing surface is limited by the strength of the first and second members constituting the opposing surface. There is.

  The present invention has been made on the basis of the above-mentioned knowledge of the present inventor, and the technical problem thereof is a fixing mechanism for a rotatable connecting portion in which the first and second members can be screwed at arbitrary rotational positions. In the present invention, it is possible to generate a frictional force that opposes a larger rotational force with a configuration in which the connecting portion of both members can be easily machined, and to provide a fixing mechanism that can easily release the fixing of both members. There is.

  In order to solve the above-described problem, according to the present invention, the first member and the second member that can be screwed to the first member at an arbitrary rotational position around the axis set on the first member. The two members are provided with screw holes for screwing a tightening screw between the two members on the axis, and the opposing surfaces of the two members around the screw hole are brought into surface contact with each other. In the fixing mechanism of the rotatable connecting portion formed with the friction surface pressed by the tightening screw, the friction surface has a radial length from the outer periphery of the facing surface of the first and second members to the screw hole peripheral wall. The first and second members are in contact with each other only at their friction surfaces, and the opposing surfaces of the first and second members are Inside the contacting friction surface, tighten the tightening screw above. However, it is formed as a spaced-apart portion that does not come into contact with each other, so that the tightening force of the tightening screw acts only between the friction surfaces of the opposing surfaces. A mechanism for fixing the rotational connection is provided.

  In the first rotatable connecting portion fixing mechanism according to the present invention, the pair of the first members is formed in a cylindrical shape having a common screw hole with their axes arranged on the same straight line. A pair of the first composite member and the second member provided with opposing surfaces facing each other around the screw holes on the both end surfaces thereof are arranged on the same straight line. The opposing surfaces around the screw holes are arranged so as to face each other at an interval, and the opposing surfaces are pressed against the opposing opposing surfaces of the pair of first members. A second composite member disposed so as to be close to each other in a state where the first composite member and the second composite member are not positioned, and a single fastening screw is provided in a screw hole provided on an axis of the first composite member and the second composite member. By screwing and tightening, the pair of second members is displaced. Pressed against the pair of first members Te can tightening force of 該締 with screw is configured to act between the friction surface of the outer peripheral portion of each of the opposing surfaces.

  In the first rotatable connecting portion fixing mechanism according to the present invention, the friction surface on the opposing surface of the first and second members is 1/5 of the outer peripheral radius from the outer periphery of the opposing surface. It is desirable to form in the range exceeding.

  In the first rotatable connecting portion fixing mechanism of the present invention having the above-described configuration, the friction surface on the opposing surface of the first and second members is a radial direction from the outer periphery of the opposing surface to the outer periphery of the screw hole. It is formed on the outer peripheral portion of the opposing surface as having a radial width that is less than half the length, and the opposing surfaces of the first and second members are mutually connected by tightening the tightening screw inside the friction surface. The tightening force by the tightening screw acts only between the friction surfaces of the outer peripheral portion of the facing surface, including the force that should originally act on the facing surface of the spacing portion. Therefore, extremely strong frictional force can be exhibited as compared with a known general fixing mechanism.

  Specifically, in the fixing mechanism, when the outer peripheral radius of the opposing surface is R, the radial width of the friction surface is a, and a = R / 3, Assuming that the normal force on the surface acts equally on the entire surface of the friction surface, the resultant force acts on the friction surface at a radial position that bisects the area of the friction surface in the radial direction. , The radius position is calculated to be approximately 0.85R from the center. The assumption that a = R / 3 is assumed is that the radial width a of the friction surface is a when the peripheral wall radius of the screw hole (approximately the radius of the inner peripheral position of the opposing surface) b is b = R / 3. Is equivalent to half the radial length from the outer periphery of the opposing surface to the peripheral wall of the screw hole.

  As described above, the first and second members at the position of 0.85R from the center are configured by tightening the first and second members with the tightening screw using only the R / 3 portion on the outer peripheral side of the facing surface as a friction surface. In the peripheral part of the two members, a total normal force can be applied between the two members. Therefore, the friction surface is set within a range in which a part of the first and second members does not reach the limit of strength. By moving closer to the peripheral side of the opposing surfaces of the two members, the frictional force acting on the frictional surface can be greatly increased even if the tightening force of the tightening screw is not so large. A frictional force that opposes a large rotational force acting on the member can be generated between the friction surfaces. Moreover, the processing of the first and second members for that purpose is also simply to adjust the installation position of the friction surface, so that it can be easily performed without any special processing cost.

  Further, the first and second members fixed by tightening the tightening screw can be easily released by loosening the frictional surface by a slight unscrewing rotation of the tightening screw. However, each of the opposing surfaces of the first and second members is provided with a meshing portion projecting a large number of protrusions extending radially from the center so as to be able to mesh with each other, and the meshing position is set in the rotational direction. Even if it is shifted and fixed with a tightening screw at a multistage rotational position, the fixation can be easily released.

  Furthermore, in order to solve the above-described problems, according to the present invention, the first member and the first member can be screwed at an arbitrary rotational position around an axis set on the first member. A screw hole for inserting a tightening screw between the two members on the axis, and between the opposing surfaces of the two members around the screw hole. In the rotatable coupling portion fixing mechanism in which an annular friction member that is brought into surface contact with the opposing surface and pressed by the tightening screw is disposed, the annular friction member is an outer periphery of the opposing surfaces of the first and second members. And having a radial width that is not more than half the radial length from the peripheral wall of the screw hole to the outer peripheral side of the opposing surface, and is formed on the opposing surfaces of the first and second members. Is the radial width of the friction member. A friction surface that is in contact with the surrounding surface is formed, and an inner side of the friction surface is formed as a separation portion that does not come into contact with each other even by tightening of the tightening screw, whereby the tightening force of the tightening screw can be The second rotatable connecting portion fixing mechanism is provided so as to act on the friction member only on the friction surface.

  In the fixing mechanism for the second rotatable connecting portion according to the present invention, the pair of the first members is formed in a cylindrical shape having a common screw hole with their axes arranged on the same straight line. A pair of the first composite member and the second member provided with opposing surfaces facing each other around the screw holes on the both end surfaces thereof are arranged on the same straight line. The opposing surfaces around the screw holes are arranged so as to face each other with a gap therebetween, and the opposing surfaces are opposed to the opposing surfaces facing the back of the pair of first members. A second composite member disposed so as to be positioned close to the friction member without being pressed against the friction member, and a single screw hole provided on an axis of the first composite member and the second composite member. By screwing in and tightening the tightening screw, the second part The pair is pressed against the friction member is displaced, it can be configured to tightening force of 該締 with screw acts on the friction member between the respective facing surfaces.

  Moreover, in the fixing mechanism of the second rotatable connecting portion according to the present invention, the radial width of the annular friction member is configured to exceed 1/5 of the outer peripheral radius of the friction member. Is desired.

  In the second rotation connecting portion fixing mechanism of the present invention having the above-described configuration, the first fixing mechanism directly contacts the friction surfaces formed on the first and second members. On the other hand, a friction member is interposed between the first and second members, and the friction surfaces of the first and second members are opposed to each other. Although each has a friction surface, there is no difference in basic operation, and it can function in the same manner as the first fixing mechanism, and the tightening force of the tightening screw is excessive as in the first fixing mechanism. Even when the frictional force is not large, the frictional force acting on the frictional surface is very large, and when the first and second members are unfixed, the fixing can be easily performed by slightly unscrewing the tightening screw. It becomes possible to cancel.

  In a preferred embodiment of the first and second fixing mechanisms according to the present invention, a fitting portion that is rotatably fitted to each other is provided around the opposing surfaces of the first and second members. Thus, a closed space is formed between the opposed surfaces, and the axial line at the center of the opposed surfaces of the first and second members is prevented from being displaced, and at the same time, the closed space can be protected from dust. This configuration is also effective for reinforcing the friction surfaces pressed against each other by tightening the tightening screw.

  Further, as another preferred embodiment of the fixing mechanism according to the present invention, one of the first member and the second member can be attached to a support leg member, and the other can be attached to a mounting device to be supported in an arbitrary posture. The pan / tilt head can be configured so as to be integrated with or fixed to the supporting base member.

  According to the fixing mechanism of the rotatable connecting part of the present invention described in detail above, in the fixing mechanism of the rotatable connecting part in which the first and second members can be screwed at arbitrary rotational positions, the two members are connected. It is possible to provide a fixing mechanism that can generate a frictional force that opposes a larger rotational force with a simple configuration and that can easily release the fixing of both members.

It is principal part sectional drawing which shows 1st Example (basic form) of the fixing mechanism of the rotatable connection part which concerns on this invention. It is a principal part front view of the said 1st Example. FIG. 4 is a diagram for explaining the details of the configuration of the first and second members (both of which have the same shape) in the first embodiment, and FIG. Part front view, (b) is a longitudinal sectional view of the main part of the same member. It is sectional drawing which shows the structure of 2nd Example of the fixing mechanism of the rotatable connection part which concerns on this invention. It is sectional drawing which shows the structure of 3rd Example of the fixing mechanism of the rotatable connection part which concerns on this invention. It is sectional drawing which shows the structure of 4th Example of the fixing mechanism of the rotatable connection part which concerns on this invention. It is a disassembled sectional view which decomposes | disassembles and shows the main elements of the said 4th Example.

  1 to 3 show a first embodiment (basic form) of a fixing mechanism for a rotatable connecting portion according to the present invention. The rotatable connecting portion 1A in this fixing mechanism holds, for example, a support base member to which a mounting device such as a camera, a lighting fixture, and various measuring instruments is attached in a required posture by a support leg member such as a tripod or a stand. Or when orienting their posture or orientation in a required direction, between a plurality of connecting struts constituting the support leg member, or between the strut and the support base member, A pan head or the like is incorporated so that they can be fixed at an arbitrary bending position.

In the first embodiment and each embodiment of the present invention described below, the one that can be integrated or fixed with one of the support leg member and the support base member is called the first member and integrated with the other. Or what can be fixed is called the 2nd member. The first member 11 and the second member 12 can be fixed with screws at arbitrary rotational positions, whereby the fixing mechanism of each embodiment is fixed to a rotatable connecting portion called a pan head. The mechanism is configured.
The rotatable connecting portion 1A is not limited to use as a pan head.

  In the first embodiment shown in FIGS. 1 to 3, the rotatable connecting portion 1 </ b> A is set on the first member 11 on the fixed side corresponding to the support leg member and the like, and on the first member 11. A movable second member 12 corresponding to the support base member, which can be screwed to the first member 11 at an arbitrary rotational position around the axis L, is provided on both the members 11 and 12. Is provided with coaxial screw holes 11a and 12a for screwing the tightening screw 13 between the two members on the axis L, and the tightening screw 13 is inserted into the screw holes 11a and 12a. By screwing, both the members 11 and 12 are formed on the axis L so as to be tightened.

  As shown in FIGS. 3A and 3B, the first member 11 has a circular facing surface 11b around the screw hole 11a, and the second member 12 is also a second member 12. Since it has the same shape as the first member, it has a similar facing surface 12b around the screw hole 12a. As can be clearly seen from FIG. 1, an annular friction surface pressed against the opposing surfaces 11 b, 12 b of the first and second members 11, 12 by being brought into surface contact with each other and pressed by the tightening screw 13. 11c and 12c are formed. The radial width a of the friction surfaces 11c and 12c is less than half of the radial length c from the outer periphery of the pair of opposing surfaces 11b and 12b to the peripheral walls of the screw holes 11a and 12a around the axis L. It is formed in the outer peripheral side part of this opposing surface 11b, 12b as what has a dimension.

  When the first and second members 11, 12 having the above-described configuration are tightened by the tightening screw 13, the first and second members 11, 12 are in contact with each other only at both friction surfaces 11 c, 12 c. , 12 are formed as spaced-apart portions that do not come into contact with each other even by tightening of the tightening screw 13 inside the contacting friction surfaces 11c, 12c. The tightening force is applied only between the friction surfaces 11c and 12c of the opposing surfaces 11b and 12b.

  As described above, the friction surfaces 11c and 12c are formed so as to have a radial width not more than half of the radial length from the outer periphery of the opposing surfaces 11b and 12b to the peripheral walls of the screw holes 11a and 12a. However, it is generally desired that the radial width a be formed within a range exceeding 1/5 of the outer peripheral radius from the outer periphery of the facing surfaces 11b and 12b. Since part of the first and second members 11 and 12 constituting the facing surfaces 11b and 12b may be damaged, the mechanical strength of each part of the first and second members 11 and 12 is sufficient. Consideration is necessary.

  In the fixing mechanism of the first embodiment having the above-described configuration, the friction surfaces 11c and 12c on the opposing surfaces 11b and 12b of the first and second members 11 and 12 are connected to the screw holes 11a and 12a from the outer periphery of the opposing surfaces. And having a radial width a equal to or less than half of the radial length c to the peripheral wall, the opposing surfaces 11b and 12b are formed on the outer peripheral side portion, and the opposing surfaces 11b and 12b are formed on the friction surfaces 11c and 12c. The inner side is formed as a spaced-apart portion that does not contact each other even when the tightening screw 13 is tightened. Therefore, the tightening screw 13 is compared with the case where the tightening force by the tightening screw 13 is applied to the entire opposing surfaces 11b and 12b. The tightening force due to can be applied only between the friction surfaces 11c and 12c on the outer peripheral side of the opposed surfaces 11b and 12b, including the force that is originally applied to the separation portion. From the viewpoint, in particular, since the radial width of the separation portion of the facing surfaces 11b and 12b is larger than the radial width of the friction surfaces 11c and 12c, the tightening force by the tightening screw 13 is concentrated on the friction surface. It acts and a very strong frictional force can be generated between the friction surfaces 11c and 12c.

  The rotatable connecting portion 1A of the first embodiment is configured to fasten the single first member 11 and the single second member 12 with the fastening screw 13 on the axis L. The fixing mechanism can have a configuration in which a pair of the rotatable connecting portions 1A of the first embodiment is provided as in the rotatable connecting portion 1B of the second embodiment shown in FIG. That is, in the second embodiment, a pair of the first members 11 is formed in a cylindrical shape in which the axis L is arranged on the same straight line and a common screw hole 11a is provided at the center thereof. Then, the opposing surfaces 11b, 11b facing each other are arranged around the screw holes 11a on both end faces, and fixed to the support leg member 25 attached to a tripod or the like to form the first composite member 21, Further, the second composite member 22 in which a pair of the second members 12 is attached to the support base member 26 has a pair of axes of the second member 12 on the same straight line, and each screw hole 12a. The opposing surfaces 12b and 12b around the surface of the first composite member 21 are arranged so that the opposing surfaces 12b and 12b are opposed to each other with a gap therebetween, and the opposing surfaces 11b and 11b of the first composite member 21 face away from each other. Respective friction surfaces 11c, 12 There has been arranged to be positioned in close proximity in a state which is not pressed.

  In the rotatable connecting portion 1B of the second embodiment, a single fastening screw 13 is inserted into the screw holes 11a and 12a provided on the axes of the first composite member 21 and the second composite member 22, When the tightening nut 14 is screwed into the pair, the pair of the second members 12 is elastically displaced or minutely displaced so that the opposing surfaces 12b and 12b are the first members in the first composite member 21. 11 is pressed in the direction of pressing against the pair of opposing surfaces 11b, 11b, and the tightening force of the tightening screw 13 acts between the friction surfaces 11c, 12c on the outer peripheral side portions of the opposing surfaces 11b, 11b. ing. The elastic displacement of the second member 12 is due to elastic deformation of the second member 12 itself, and the minute displacement of the second member 12 adds a slight slack to the fixing to the support base member 26. Can be obtained. In addition, the code | symbol 27 in a figure has shown the mounting seat of the various mounting apparatuses attached to the support base member 26. FIG.

  According to the fixing mechanism of the second embodiment, since the pair of the rotatable connecting portions 1A of the first embodiment is provided side by side, the second composite is achieved by tightening the tightening screw 13 with the tightening nut 14. The pair of facing surfaces 12b, 12b of the member 22 are pressed in a direction to press against the pair of facing surfaces 11b, 11b of the first composite member 21, and the tightening force of the tightening screw 13 is the outer peripheral side of each of the facing surfaces 11b, 12b. It acts between the friction surfaces 11c and 12c in the portion, and the rotation of the second composite member 22 is suppressed by almost twice the friction force.

  FIG. 5 shows a rotatable connecting portion 1C of the third embodiment of the fixing mechanism according to the present invention. Similar to the first embodiment, the first member 11 and the first member The first member and the second member 12 that can be screw-fixed at an arbitrary rotational position around the axis L set to the above-mentioned position are provided between the two members 11 and 12 on the axis L. Screw holes 11a and 12a for screwing the tightening screw 13 are provided, opposing surfaces 11b and 12b of both members 11 and 12 are provided around the screw holes 11a and 12a, and friction surfaces 11c and 12c are provided on the outer peripheral side portions, respectively. However, between the friction surfaces 11c and 12c, an annular friction member 23 that is brought into surface contact with the friction surfaces 11c and 12c and pressed by the tightening of the tightening screw 13 is disposed.

  Specifically, the friction member 23 has a radial length from the outer periphery of the opposing surfaces 11b and 12b of the first and second members 11 and 12 to the peripheral wall of the screw holes 11a and 12a (see c in FIG. 3). (Corresponding: Same for both members 11 and 12) As an annular shape having a radial direction width equal to or less than half of the members, the surface is in contact with the outer peripheral friction surfaces 11c and 12c of the opposing surfaces 11b and 12b The friction surfaces 11c and 12c on the opposing surfaces of the first and second members 11 and 12 are formed so as to contact the friction member 23 in the range of the radial width thereof. Further, the opposed surfaces 11b and 12b inside the friction surfaces 11c and 12c are formed as spaced portions that do not contact each other even when the tightening screw 13 is tightened, whereby the tightening screw 13 and the nut for tightening are formed. The tightening force by 14 acts on the friction member 23 only on the friction surfaces 11c and 12c of the opposing surface.

  In the first embodiment, the fixing mechanism of the third embodiment having the above configuration directly presses the friction surfaces 11c, 12c of the first and second members 11, 12 against each other. The friction member 23 is interposed between the friction surfaces 11c and 12c, and there is a structural difference in the presence or absence of the friction member 23. Therefore, substantially the same type of effect as the first embodiment is achieved, and Since the friction member 23 exists as a separate member, for example, when the first and second members 11 and 12 are made of aluminum or an aluminum alloy, a friction member made of metal or the like having excellent friction characteristics with the first and second members 11 and 12 is used. It has a secondary effect such that it can be used or can be easily replaced when the friction member is worn.

6 and 7 show a rotatable connecting portion 1D of the fourth embodiment of the fixing mechanism according to the present invention. The fourth embodiment is similar to the third embodiment in the fixing mechanism of the second embodiment described in detail with reference to FIG. 4, and the friction surfaces 11c of the first and second members 11 and 12 are similar to the third embodiment. , 12c, a friction member 23 is interposed.
That is, the first composite member 21 and the second composite member 22 which are the same as those in the second embodiment are provided, and a single fastening screw 13 is screwed into the screw holes 11a and 12a provided on the axes thereof. By inserting and tightening, the pair of second members 12 is displaced and pressed against the friction member 23 so that the tightening force of the tightening screw 13 acts on the friction member 23 between the opposing surfaces 11b and 12b. It is composed.

Since the configuration other than the above in the fourth embodiment is the same as that in the third embodiment, the same or corresponding parts in FIG. 6 and FIG. Is omitted.
Further, as described above, the friction member 23 in the third and fourth embodiments has a diameter that is not more than half the radial length from the outer periphery of the opposing surfaces 11b and 12b to the peripheral wall of the screw holes 11a and 12a. Although it is formed as having a directional width, the radial width a is generally formed within a range exceeding 1/5 of the outer peripheral radius from the outer periphery of the facing surfaces 11b and 12b. Desirably, if it is smaller than the range, a part of the first and second members 11 and 12 constituting the opposing surfaces 11b and 12b and the friction member 23 itself are tightened by the tightening screw 13 and the tightening nut 14. Care must be taken to prevent damage.

Incidentally, the friction member 23 as shown in FIG. 6 is used for the outer peripheral portion of the opposing surfaces 11b and 12b having the outer peripheral radius R, and the radial width a of the friction member 23 is the limit of the preferable radial width in the present invention. In the case where the outer peripheral radius R of the member 23 is 1/5 and the opposing surfaces 11b and 12b are not in contact with each other on the inner side, the resultant force of the frictional force in the frictional member 23 is calculated according to the above-described approximation. When determining the radial position on the friction surface that acts, first, the area where one surface of the friction member 23 is in contact with the opposing surface is:
4π [R ² − (0.8R) ² ] = 1.44πR ²
Assuming that the resultant force of the frictional force acts at a radial position that bisects the contact area of the friction member in the radial direction, the radial position is calculated from the outer periphery of the opposing surface by the above area. It is a radial position that occupies 0.72πR ² that is 1/2, and when this is rewritten as 4πR ² · 0.18, the area of each half of the inner and outer sides of the friction surface is 0 of the total area of the circle of radius R 18 times. Based on this, the position of the radius r that bisects the area of the friction surface in the radial direction is 4πR ² -4πr ² = 4πR ² · 0.18. When r is calculated by eliminating 4π, R ² Since −0.18R ² = r ² , r≈0.906R.
That is, a resultant force of the frictional force acts on the friction surface at a radial position of approximately 0.91R from the center, and the frictional force between the frictional members disposed between the opposing surfaces is applied to the rotational movement of the two members. It can act as a very large resistance (moment).

  Further, a fitting portion 24 is provided around the opposing surfaces 11b and 12b of the first and second members 11 and 12 in the second to fourth embodiments described above so as to be rotatably fitted to each other. Although a closed space is formed between the opposed surfaces, the fitting portion 24 prevents the axial lines of the centers of the opposed surfaces 11b and 12b of the first and second members from being displaced, and at the same time, the closed space. It is effective for preventing dust and the like, and is also effective for reinforcing the friction surfaces 11c and 12c and the friction member 23 that are pressed against each other by tightening with the tightening screw 13 and the tightening nut 14.

11 First member 11a, 12a Screw hole 11b, 12b Opposing surface 11c, 12c Friction surface 12 Second member 13 Clamping screw

Claims (8)

A first member; and a second member that can be screwed to the first member at an arbitrary rotational position around an axis set on the first member. A screw hole for inserting a tightening screw between the two members on the wire is provided, and a friction surface that is pressed against the tightening screw by being in surface contact with each other is formed around the screw hole. In the fixing mechanism of the rotary connecting part,
The friction surface is formed on an outer peripheral side portion of the opposing surface that is not more than half of the radial length from the outer periphery of the opposing surface of the first and second members to the peripheral wall of the screw hole. The two members are in contact with each other only at the friction surface, and the opposing surfaces of the first and second members can be in contact with each other also by tightening the tightening screw inside the contacting friction surface. Configured so that the tightening force of the tightening screw acts only between the friction surfaces of the opposing surfaces.
A fixing mechanism for a rotatable connecting portion. The fixing mechanism according to claim 1,
A pair of the first members are formed in a cylindrical shape having a common screw hole with the axes thereof arranged on the same straight line, and opposing surfaces facing each other around the screw holes at both end faces thereof The pair of the first composite member and the second member are arranged so that their axes are on the same straight line and the opposing surfaces around the respective screw holes are opposed to each other with a gap therebetween. And a second composite in which the opposing surfaces are positioned so as to be located close to the opposing opposing surfaces of the pair of first members in a state where the respective friction surfaces are not pressed against each other. With members,
By screwing a single tightening screw into a screw hole provided on the axis of the first composite member and the second composite member and tightening, a pair of the second member is displaced and the first member of the first composite member is displaced. Pressed against a pair, and configured such that the tightening force of the tightening screw acts between the friction surfaces on the outer peripheral side portion of each opposing surface.
A fixing mechanism for a rotatable connecting portion. The fixing mechanism according to claim 1 or 2,
The friction surface on the opposing surface of the first and second members is formed within a range exceeding 1/5 of the outer peripheral radius from the outer periphery of the opposing surface.
A fixing mechanism for a rotatable connecting portion. A first member; and a second member that can be screwed to the first member at an arbitrary rotational position around an axis set on the first member. A screw hole for screwing a tightening screw between the two members is provided on the line, and an annular ring is pressed between the opposing surfaces of the two members around the screw hole and brought into surface contact with the opposing surfaces. In the fixing mechanism of the rotatable connecting portion provided with the friction member,
The annular friction member has a radial width equal to or less than half the radial length from the outer periphery of the opposing surfaces of the first and second members to the peripheral wall of the screw hole, and on the outer peripheral side of the opposing surface. A friction surface is formed on the opposing surfaces of the first and second members so as to be in contact with the friction member in the range of the radial width thereof, and the inner surface of the friction surface is formed. Is formed as a spaced-apart portion that does not come into contact with each other even when the tightening screw is tightened, so that the tightening force of the tightening screw acts on the friction member only on the friction surface of the opposing surface. ,
A fixing mechanism for a rotatable connecting portion. The fixing mechanism according to claim 4,
A pair of the first members are formed in a cylindrical shape having a common screw hole with the axes thereof arranged on the same straight line, and opposing surfaces facing each other around the screw holes at both end faces thereof The pair of the first composite member and the second member are arranged so that their axes are on the same straight line and the opposing surfaces around the respective screw holes are opposed to each other with a gap therebetween. And the opposing surfaces of the pair of first members are disposed so as to be close to the opposing opposing surfaces of the pair of first members in a state where the friction surfaces are not pressed against the friction member. A second composite member,
By screwing a single tightening screw into a screw hole provided on the axis of the first composite member and the second composite member and tightening, a pair of the second member is displaced and pressed against the friction member. The tightening force of the tightening screw is configured to act on the friction member between the opposing surfaces.
A fixing mechanism for a rotatable connecting portion. The fixing mechanism according to claim 4 or 5,
The radial width of the annular friction member exceeds 1/5 of the outer peripheral radius of the friction member,
A fixing mechanism for a rotatable connecting portion. Provided around the opposing surfaces of the first and second members is a fitting portion that is rotatably fitted to each other, thereby forming a closed space between the opposing surfaces.
The fixing mechanism for the rotatable connecting portion according to any one of claims 1 to 6. One of the first member and the second member can be integrated or fixed with a support leg member, and the other can be mounted with a mounting device to be supported in an arbitrary posture. Make up the stand,
The fixing mechanism for the rotatable connecting portion according to any one of claims 1 to 7.

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