JP2007162868A - Turnable lifting tool unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turnable lifting tool unit which is unitized without requiring a snap ring. <P>SOLUTION: A bush 4 comprises an upper bush part 41 which abuts on a head section 1c of a fastening member 1, and a lower bush part 42 which abuts on an object 10 to be lifted. The lower bush part 42 is provided with a female thread section 42c to be screwed on a male thread section 1a of the fastening member 1. A second incomplete thread section 1d is formed between the male thread section 1a and an incomplete thread section 1b of the fastening member 1. The second incomplete thread section 1d has an axial length which is set larger than that of the female thread section 42c of the lower bush part 42, and also has a diameter smaller than an outer diameter of the incomplete thread section 1b so that the lower bush part 42 is freely rotatably fitted in and held by the second incomplete thread section 1d. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a swingable holding tool (link bolt) that is used as a hanging work in various work sites such as construction, construction, cargo handling, and on-site work, and is particularly integrated in a stable state. The present invention relates to a swivel suspension unit.

  Conventionally, eyebolts have been widely used at various work sites as suspension pieces for suspension work. This eyebolt is mounted in a fixed state by screwing the bolt part into the object to be suspended or fastened with a nut, and is used not only for suspending work but also for lifting or reversing heavy objects. Sometimes. However, since the eyebolt is fastened to the suspension object in a fixed state, there is a problem that it easily deforms when the direction of the suspension load changes.

  Therefore, in order to eliminate such difficulties, for example, a swivel connector as shown in FIG. 5 has been proposed (see, for example, Patent Document 1). In this swivel connector, a leg end of a link member 3 bent in a substantially U shape is bent inward to be locked in an opening of the housing 2, and a bolt hole formed in the housing 2 is provided with a flange. The anchor unit (bolt) 1 is assembled through the upper bush 41 and the lower bush 42 so that the snap ring (retaining ring) e is engaged with the groove formed in the male screw 1a of the anchor unit 1 in the assembled state. By stopping, both bushes 41 and 42 are kept from coming off and the whole is unitized.

After being transported, stored, etc. in such a unitized state, it is handled in this state during use, and is carried into the field, and the anchor unit 1 is screwed and fixed to the object to be held 10 and then hooked to the link member 3. As described above, operations such as hanging work, lifting heavy objects, and reversing work are performed. In many cases, after the work is finished, the anchor unit 1 is removed from the object to be hung, stored in a unitized state, and used again.
Japanese Patent No. 2761660

  However, in the conventional swivel coupler, the snap ring e is often damaged when the anchor unit 1 is removed from the object 10 to be held. That is, since the width (for example, 2.7 mm) of the groove formed in the threaded portion of the anchor unit 1 is considerably wider than the thickness (for example, 1 mm) of the snap ring e, the snap ring e is locked. Was prone to instability. Therefore, when the anchor unit 1 is tightened against the object 10 to be held, even if the snap ring e is normally locked, when the anchor unit 1 is loosened, the snap ring e follows the male screw 1a. It often deformed and slipped out, and at that time it was damaged. Further, when the anchor unit 1 is tightened against the object 10 to be suspended, the snap ring e sometimes gets stuck in the male screw 1a of the anchor unit 1, but in such a case, if the anchor unit 1 is loosened, The snap ring e was definitely deformed or damaged.

  Further, in the conventional swivel coupler, in order to accommodate the snap ring e, the inside of the flange of the lower bush 42 is cut out in an arc shape to form a countersink portion Z. Therefore, the flange area of the lower bush 42 that contacts the suspended object 10 is reduced by the counterbore portion z. Therefore, when the anchor unit 1 is fastened to the suspension object 10, not only the load per unit area received by the flange 15a is increased, but also a step is formed by the countersink portion Z, so that stress concentration occurs in that portion. There is also a problem that the lower bush 42 is easily deformed or broken.

  This invention is made | formed in view of such a situation, and it aims at providing the rotation suspension tool unit unitized without requiring a snap ring. Another object of the present invention is to make the bushing difficult to break in such a swivel suspension unit.

(1) The swivel holding device unit of the present invention has an incomplete screw portion between the male screw portion and the head portion and is fixed to the object to be held, and rotatably supports the fastening member. A housing for the hook, a link member that is swingably supported by the housing to hang a hook or the like, and a bush that is interposed between the housing and the fastening member in a retaining state,
The bush includes an upper bush that comes into contact with the head portion of the fastening member and a lower bush that comes into contact with the object to be suspended. The lower bush has a female screw portion that is screwed into a male screw portion of the fastening member. On the other hand, between the external thread part and the incomplete thread part of the fastening member, the length in the screw axis direction is set larger than the internal thread part of the lower bush and the outer diameter of the incomplete thread part A second incomplete thread portion is formed which has a smaller diameter and holds the lower bush in a freely fitted state.

  According to such a configuration, the upper bush is fitted into the fastening member, and the fastening member is inserted into the housing (the bolt hole) together with the upper bush, and then the lower bush is screwed into the fastening member. Since the lower bushing is held in a freely-fitted state when it falls into the part, the fastening member, the housing, the link member, the upper bushing, and the lower bushing are unitized. Therefore, as in the prior art, unitization is facilitated without requiring separate members (snap rings) or tools.

  Since the second incomplete thread portion formed to have a diameter smaller than the outer diameter of the incomplete thread portion is set to be longer in the screw shaft direction than the female thread portion of the lower bush, The bush is held in a state of being freely fitted to the second incomplete screw portion, and even if the fastening member is loosened after use, the lower bush does not ride on the male screw of the fastening member and is not damaged.

(2) The lower bush includes a bush main body fitted into the fastening member, and a flange that is formed at one end of the bush main body and abuts against a suspended object, and the surface of the flange forms a countersink portion. It may be formed in a flat shape without touching the object to be suspended. In this way, in use, since the load is applied to the entire outer surface of the flange formed flat, the load per unit area is less than when a countersink is formed on the flange as in the past, Stress concentration hardly occurs and durability is improved.

  In the swivel suspension unit of the present invention, the length in the screw shaft direction is set larger between the male screw portion and the incomplete screw portion of the fastening member than the female screw portion of the lower bush, and the incomplete screw portion Since the second incomplete thread portion is formed to have a smaller diameter than the outer diameter and hold the lower bush in a loosely fitted state, the upper bush is fitted into the fastening member, and the fastening member is After being inserted into the bolt hole of the housing together with the upper bush, if the lower bush is screwed into the fastening member and dropped into the second incomplete thread portion, the lower bush is held in a loosely fitted state, so that the fastening member The housing, the link member, the upper bushing and the lower bushing are in a unitized state, and there is no need for separate members (snap rings) or tools as in the past. It becomes easy.

  Since the second incomplete thread portion formed to have a smaller diameter than the outer diameter of the incomplete thread portion is set to be longer in the screw shaft direction than the internal thread portion of the lower bush, The bush is held in a free-fitting state with respect to the second incomplete screw portion, and even if the fastening member is loosened after use, the lower bush does not ride on the male screw of the fastening member and be damaged. .

  In addition, if the surface of the flange is formed flat (without forming a countersink) and the entire surface is brought into contact with the object to be suspended, a load is applied to the entire outer surface of the flange during use. Therefore, the load per unit area is reduced as compared with the conventional case where a countersink is formed on the flange, and stress concentration is less likely to occur, resulting in improved durability.

Hereinafter, a swivel holding device unit according to the preferred embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows the structure of a swivel lifting fixture unit. Reference numeral 1 denotes a fastening member such as a hexagon bolt that is fastened and fixed to an object to be suspended 10, and 2 rotatably supports the fastening member 1 in a retaining state. This is a housing that is formed in a substantially hollow cylindrical shape with an open bottom. Reference numeral 3 denotes a link member that is swingably supported by the housing 2, on which a hook or the like is hung. Reference numeral 4 denotes a bush, which includes an independently formed flanged upper bush 41 and a lower bush 42, and is inserted into an anchor unit (bolt) 1 and inserted into a bolt hole formed in the housing 2, and the lower bush. 42 is held in a state where it can be freely loosened by the fastening member 1, so that the whole is unitized.

  The swivel holding device unit is handled in such a unitized state, is transported, stored, etc., is also handled in this state at the time of use, is brought into the site, and is attached to the object 10 to be suspended. Then, a hook or the like is hung on the link member 3 to lift, pull up, reverse, or the like. And in many cases, after completion | finish of work, the fastening member 1 is removed from the suspension target object 10, and as described above, it is stored in a united state and is used again. In addition, the fastening member 1 may be fixed by screwing with respect to the suspension target object 10, and may be fixed by fastening of a nut.

  The entire configuration will be described in detail. As shown in FIG. 2, the fastening member 1 is composed of, for example, a hexagonal bolt, and has a male screw portion 1a, an incomplete screw portion 1b, and a head portion 1c, and the incomplete screw portion. An upper bush 41 is fitted into 1b, and the upper bush 41 includes a cylindrical portion 41b fitted into the incomplete thread portion 1b of the hexagon bolt 1 and a flange portion 41a formed at the upper end thereof. The lower surface of 41 a is seated on a countersunk portion formed around the bolt hole of the housing 2, and the upper surface abuts against the head portion 1 c of the hexagon bolt 1.

  The lower bush 42 includes a cylindrical portion 42b that is fitted into the lower portion of the incomplete thread portion 1b of the hexagon bolt 1 and a flange portion 42a that is formed at the lower end of the cylindrical portion 42b. On the other hand, a female screw portion 42c that is screwed into the male screw portion 1a of the hexagon bolt 1 is formed, while a second incomplete screw portion 1d is formed between the male screw portion 1a and the incomplete screw portion 1b of the hexagon bolt 1. Yes.

  The length k2 of the second incomplete screw portion 1d in the screw axis direction is set to be larger than the length k1 of the female screw portion 42c of the lower bush 42 in the screw axis direction, and the second incomplete screw portion 1d The outer diameter d2 is formed smaller than the outer diameter d1 of the incomplete thread portion 1b. Therefore, after the upper bush 41 is fitted into the hexagon bolt 1 and the hexagon bolt 1 is inserted into the bolt hole of the housing 2 together with the upper bush 41, the lower bush 42 is screwed into the hexagon bolt 1 and the second incomplete thread portion. If it falls into 1d, the lower bushing 42 is held in a fitted state so as to be freely rotatable on the second incomplete threaded portion 1d, whereby the swivel suspension unit is unitized. Therefore, as in the prior art, unitization is facilitated without requiring separate members (snap rings) or tools.

  In the unitized state, the lower bush 42 is fitted and held on the second incomplete screw portion 1d with some backlash, and is handled in this state, and the hexagon bolt 1 is fastened to the suspension object 10. In the state, as shown in the enlarged view of FIG. 1, gaps s1 and s2 are generated above and below the female thread portion 42c of the lower bush 42 (k2> k1). That is, for example, when the hexagonal bolt 1 is M30 × 3.5, a gap s1 of about 1.5 mm is provided between the lower end of the incomplete screw portion 1b and the upper end of the female screw portion 42c, and the lower end of the female screw portion 42c and the male screw portion 1a. It is preferable to set a gap s2 of about 3 mm between each of the upper ends of the two. Therefore, it is preferable to set k2 = k1 + 4.5 mm.

  By forming such gaps s1 and s2, the lower bushing 42 rides on the male threaded portion 1a of the hexagon bolt 1 and is not easily removed even when the hexagon bolt 1 is loosened when releasing the fastening state of the hexagon bolt 1. There will be no such thing. Further, since the conventional counterbored portion is not formed in the flange portion 42a of the lower bush 42, when the hexagon bolt 1 is fastened, the entire surface of the flange portion 42a comes into contact with the suspended object 10. The load per unit area is smaller than when the countersink is formed, and stress concentration is less likely to occur, resulting in improved durability.

  In addition, when the hexagon bolt 1 is left fastened for a long time, the lower bush 42 may be rotated when the hexagon bolt 1 is loosened. In order to make it easy to separate the bush 42, a locking hole (a pair) may be formed at the diagonal position of the flange portion 42a of the lower bush 42, or the peripheral edge of the flange portion 42a may be cut at the diagonal position. The values of k1, k2, s1, and s2 described above may be appropriately selected according to design conditions such as the diameter of the hexagon bolt 1.

  3 is that the thrust bearing 5 is disposed between the housing 2 and the head portion 1c of the hexagon bolt 1 with the flange portion 41a of the upper bush 41 interposed therebetween. Although different from the swivel / holding tool unit shown in FIG. 2, the configuration of unitization by the hexagon bolt 1 and the lower bush 42 is the same, and the same operational effects can be obtained. In this example, since the swivel suspension unit receives the suspension load by the thrust bearing 5 disposed between the hexagon bolt 1 and the housing 2, the hexagon bolt 1 can be used even when the direction of the suspension load changes. Since it rotates smoothly with respect to the housing 2, generation | occurrence | production of accompanying torque is suppressed low and the fixed state of the hexagon bolt 1 with respect to the suspension target object 10 is maintained stably. Further, the thrust bearing 5 does not generate a large frictional noise (abnormal noise) unlike the conventional swivel coupler that receives a load by surface contact, and noise during operation is reduced and environmental resistance is improved. Since the rotating portion of the thrust bearing 5 is covered with a cover 41b formed by hanging the periphery of the flange portion 41a, the entry of foreign matter into the rotating portion is prevented, and a smooth rotating operation can be maintained. Durability is also improved.

  4 is that the hard washer 6 is disposed between the head portion 1c of the hexagon bolt 1 and the flange portion 41a of the upper bush 41. The swivel suspension unit shown in FIGS. Although different from the tool unit, the unitized structure by the hexagon bolt 1 and the lower bush 42 is the same, and the same operational effects can be obtained. In this example, the lower surface of the hard washer 6 and the upper surface of the flange portion 41a are formed into a spherical surface that is convex upward by spherical processing, and the contact surface of the hard washer 6 is subjected to a surface treatment such as chrome plating or zinc plating. The friction coefficient of the contact surface is set to 0.10 to 0.15. In such a swivel suspension unit, even when the direction of the suspension load changes, the hard washer 6 and the flange portion 41a can flexibly cope with each other to reduce the frictional force between them, and the accompanying torque can be reduced. Generation | occurrence | production can be reduced and the fixed state of the hexagon bolt 1 with respect to the suspension target object 10 can be maintained stably.

  Note that the present invention is not limited to the embodiment, and it is free to make design changes and improvements as necessary, as long as it does not depart from the gist of the invention. The bolts are not limited to hexagonal bolts, and other bolts may be used. The configuration other than the fastening member and the lower bush is not limited at all, and an appropriate configuration may be adopted.

It is a principal part longitudinal cross-sectional front view of the rotation suspension tool unit which concerns on embodiment of this invention. It is the assembly | attachment corresponding | compatible figure of the same fastening member and a bush. It is a principal part longitudinal cross-sectional front view of the another turning hanging tool unit. It is a principal part longitudinal cross-sectional front view of the other rotation suspension tool unit. It is a principal part vertical front view of the conventional turning coupling tool.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a ... Male thread part, 1b ... Incomplete thread part, 1c ... Head part, 1d ... 2nd incomplete thread part, 2 ... Housing, 3 ... Link member, 4 ... Bush, 41 ... Upper bush, 42 ... Lower bush, 42a ... Bush body, 42b ... Cylindrical part, 42c ... Female thread part, 10 ... Hanging object

Claims (2)

A fastening member that has an incomplete screw portion between the male screw portion and the head portion and is fixed to the suspended object,
A housing for rotatably supporting the fastening member;
A link member swingably supported by the housing for hooking a hook or the like;
A bush that is interposed between the housing and the fastening member in a retaining state, and
The bush includes an upper bush that comes into contact with the head portion of the fastening member and a lower bush that comes into contact with the object to be suspended. The lower bush has a female screw portion that is screwed into a male screw portion of the fastening member. On the other hand, between the external thread part and the incomplete thread part of the fastening member, the length in the screw axis direction is set larger than the internal thread part of the lower bush and the outer diameter of the incomplete thread part And a second incomplete thread portion that is formed in a smaller diameter and holds the lower bushing in a freely fitted state.   The lower bush includes a bush main body that is fitted into the fastening member, and a flange that is formed at one end of the bush main body and abuts against an object to be suspended, and the surface of the flange is formed in a flat shape. The swivel suspension unit according to claim 1, wherein the abutment unit abuts on the suspension object.

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