JP4691901B2 - Hanging bracket - Google Patents

Description

  The present invention relates to a hanging bracket for a crane suspended article to which a crane hook is engaged.

  Suspensions such as buckets and other containers suspended from the crane and work equipment jigs are provided with appropriate suspension fittings that engage with the crane hooks. In this case, depending on the content of the work and the conditions at the work site, the hanging bracket is suitable for one of the crane hooks depending on the size of the crane hook, etc. It may not be suitable for this.

  In such a case, work is often performed using an auxiliary hanging bracket or a wire with a stand, etc., but it takes time and labor, and an appropriate jig such as an auxiliary hanging bracket or a wire with a stand is used. It is necessary to always prepare and store, so that complicated slinging work is unavoidable, and it is inevitable that the work is restricted by the quality of maintenance management of jigs and the like.

  It is also possible to attach a plurality of suspension fittings according to the size of the large and small crane hooks, but if the suspension position changes, the suspended object may deviate from the center of gravity position, causing problems such as unbalance. Many.

  There is a technique that uses a specific auxiliary suspension device between a crane hook and a suspension hand (see, for example, Patent Document 1). This technology is an auxiliary suspension device dedicated to a special device, and is always provided at a specific work position. However, in general-purpose cranes used for various types of suspended objects and various types of work, preparing a special auxiliary suspension device has a harmful effect that complicates the work.

For example, a scale transport bucket for transporting a scale generated in a rolling process of steel materials and steel pipes is transported by a large overhead crane in a factory, but in a scale accumulation site or the like, it is operated by a small crane to release contents. It has become. For this reason, conventionally, a mounting wire or the like is used for a hanging fitting that is not suitable for any crane hook, and a hanging fitting suitable for a hook for a large or small crane is desired.
Japanese Utility Model Publication No. 61-67956 (page 1-2, FIG. 2)

  The present invention has been developed in view of the above situation, the hanging bracket of the crane suspension is compatible with a plurality of types of crane hooks of large and small, and has the same position as the center of gravity of the suspension, The object is to provide a special fixture and a hanging bracket that does not require labor.

The present invention has been made to solve the above-mentioned problems, and can be shared by a plurality of types of crane hooks of large and small sizes, and has an inverted U-shape in which two parallel straight bars and a semicircular curved portion are connected in series. a shape, inverse U-engages a crane hook on the inside of the curved portion of the hanger is pulled in the direction of the straight bar by the crane hook curved portion upper end elliptical cross-section of the inverted U The major axis direction of the elliptical cross section is a direction parallel to the straight bar, and the minor axis of the elliptical cross section is smaller than the opening dimension of the smallest crane hook among the large and small types of crane hooks. Crane hook having the smallest opening dimension among the plurality of types of large and small crane hooks, with a smaller dimension so that the minor axis part of the elliptical cross section can pass through the opening part of the crane hook with the smallest opening dimension. Increasing the major axis dimension of the elliptical cross-section than the opening dimension, the portion other than the curved portion upper end is a hanger, characterized in that the major axis dimension and diameter of the elliptical cross section is equal circular cross-section .

  This hanging bracket does not require the use of an auxiliary suspension device or a wire with a base, and the suspended portions of a plurality of crane hooks have the same relative position with respect to the center of gravity of the suspended object. Convenient.

  According to the present invention, it is possible to obtain a single suspension fitting that is compatible with a plurality of types of crane hooks of large and small size and maintains the same with respect to the position of the center of gravity. There is no need to prepare and manage a special jig, and there is an excellent effect of not requiring labor such as using a wire with a base each time work is performed.

  Hereinafter, an embodiment of the present invention will be described by taking an example of a scale transport bucket as an example to which the present invention is applied.

  5-8 is explanatory drawing of the scale conveyance bucket 100 equipped with the suspension metal fitting 10 of this invention.

  The scale transport bucket 100 to be applied is a container that reciprocates between an indoor space where a large overhead crane is installed and a scale accumulation site where a small trolley crane is installed. A mechanism capable of easily changing the discharge posture is provided.

  FIG. 5 is an overall side view of the scale transport bucket 100, and FIG. 6 is a front view of the hanging hand 110. The bucket 100 includes a box-shaped box 101 having a bottom plate 104 having a wide area with an open top surface, and a suspension 110 attached to both sides of the bucket box 101 in a torii shape over the box 101. .

  The hanging hand 110 has a mechanism for lifting the bucket box 101 in a horizontal posture and a mechanism for lifting the contents in the box 101 in a vertical posture. A suspension fitting 10 is attached to the center upper end of the suspension hand 110.

  A pin 102 and a protrusion 103 are provided on the side surface of the box body 101 of the bucket, and the handle 110 is provided with a long engagement hole 111 that is rotatably engaged with the pin 102. Further, a bifurcated portion 112 provided at a position away from the engagement hole 111 is provided. The bifurcated portion 112 is locked to the projection 103 when the bucket box 101 is suspended in a horizontal position. When the contents of the box 101 of the bucket are released, the bifurcated portion 112 is detached from the protrusion 103 and is lifted only by the pin 102.

  The suspension point of the hanging bracket 10 is located substantially vertically above the center of gravity of the bucket 100 when the bucket box 101 is lifted and transported in a horizontal state, and when the contents of the box 101 are discharged, The body 101 is turned so as to be suspended from the center of gravity so that the body 101 can be rotated and lifted in a vertical state.

  The suspension hand 110 locked to the pin 102 and the protrusion 103 allows the bottom plate 104 of the large area of the bucket box 101 to stably land on the ground. When the hanging hand 110 is further loosened after landing, the above-mentioned elongated hole 111 moves downward in the hanging hand 110 and the bifurcated portion 112 is detached from the projection 103. When the bifurcated portion 112 is disengaged from the projection 103, the suspender 110 is in the posture indicated by 110b. When the suspender 110 is further loosened, the suspender 110 tilts around the pin 102, as indicated by a phantom line 110a in FIG. It becomes easy to put the scale into the box 101.

  When lifting the box 101 of the bucket, the order is reversed. When the lifting hand 110 is pulled up, the suspension hand 110 a in the standby state rises around the pin 102, the pin 102 slides in the engagement (long hole) 111, and the bifurcated portion 112 is locked to the protrusion 103. Move in the direction. When the bifurcated portion 112 is locked to the projection 103, the box 101 of the scale transport bucket 100 is lifted with the bottom plate 104 in a horizontal posture.

  FIG. 7 and FIG. 8 show the state when the contents (scale) in the box 101 of the bucket are discharged in the scale deposition site outside the factory. At this time, it is operated by a small crane such as a trolley crane.

  As shown in FIG. 5, when the suspension hand 110 a in the standby state is pulled up while slightly towing toward the left hand side in FIG. 5, the bifurcated portion 112 does not engage with the protrusion 103 of the bucket box 101, and the pin It is pulled up with only 102 and the long hole 111 engaged. FIG. 7 shows this state. When the hanging bracket 10 is pulled up as indicated by an arrow 115, the box 101 of the bucket 100 is turned 90 ° to be in a vertical posture, and the scale in the box 101 is raised. Discharge.

  Next, as shown in FIG. 8, when the hanging metal fitting 10 is lowered as indicated by an arrow 116, the front end side of the box 101 lands on the ground 106, and when further lowered, the inclined surface 105 on the bottom side of the front end side of the box 101 is formed. In contact with the ground 106, the bottom plate 104 is landed on the ground 106 due to the lowering and assumes the posture shown in FIG.

  Next, when the suspension hand 110a in the standby state shown in FIG. 5 is pulled up slightly to the right in the direction of FIG. 5, the bifurcated portion 112 of the suspension hand 110 engages with the protrusion 103 of the bucket box 101. . When the lifting bracket 10 is further pulled up in this state, the lifting hand 110 pulls up the box 101 in a horizontal posture at two points of the engagement hole 111 and the bifurcated portion 112.

  Fig.1 (a) is a front view which shows the hanging metal fitting 10 of the Example of this invention, FIG.1 (b) is the AA arrow directional view.

  The hanging metal fitting 10 of the present invention is an inverted U-shaped metal fitting attached to a suspended object, and has a shape in which two parallel straight bars 11 and a semicircular curved portion 14 are connected to each other. As shown in b), an elliptical cross section 13 is formed at the top of the semicircular curved portion 14. The portion other than the elliptical cross section 13 has a circular cross section 12 indicated by a broken line.

  FIG. 2 shows a large crane hook 21 to which the hanging bracket 10 is attached, and FIG. 3 shows a small crane hook 25. The opening 22 of the large crane hook 21 is sufficiently larger than the diameter of the suspension fitting 10 and is suspended by a large number of crane ropes 23.

  The opening 26 of the small crane hook 25 is smaller than the diameter of the conventional hanging bracket 10, and a separate wire with a stand is required to hang the conventional hanging bracket.

  In the hanging metal fitting 10 of the embodiment of the present invention, the top of the inverted U-shape is changed to an elliptical cross section 13, and the minor axis of the elliptical cross section is made smaller than the internal dimension of the opening 26 of the small crane hook 25.

  The small crane hook 25 is suspended by a single wire 27, and when the small crane hook 25 is engaged with the suspension fitting 10, the small crane hook 25 is slightly tilted so that the short diameter portion of the elliptical cross section 13 at the top of the suspension fitting 10 is obtained. The suspension bracket 10 can be engaged with the crane hook 25 by passing between the openings 26.

  In the inverted U-shaped hanging bracket 10 of the present invention, the hanging portions of the large crane hook and the small crane hook are in the same position. Therefore, even when the crane is lifted by a different crane, the hanging point is always relative to the center of gravity of the suspended object. Have the same relationship position.

  Next, mechanical considerations of the present invention will be described. As an example, consider a hanging bracket having a uniform cross section as shown in FIG. In this hanging metal fitting, two straight bars and a semicircular curved bar are connected, and the base of the straight bar is fixed.

It is assumed that the crane hook 21 is locked to the inside of the curved portion of the hanging bracket 10 and the lifting bracket 10 is pulled upward by the lifting force P. As shown in FIG. 4, P / 2 acts as a tensile force (axial force Q) on the base portion (mounting portion) of the inverted U-shaped hanging bracket 10 and a bending moment (fixed bending) generated by the pulling force P is applied. Moment) M ₀ acts.

In the portion of the straight bar 11, the axial force Q and the bending moment M ₀ have the same distribution at all positions.

  Moreover, the bending moment M shown by the following formula (1) and the axial force Q shown by the formula (2) act on an arbitrary cross section of the semicircular curved portion.

Here, r is a radius of curvature of the semicircular curved portion, and α is an angle measured from a horizontal line passing through the center of the semicircular curved portion. The above-mentioned fixed bending moment M ₀ is expressed by the following formula (3).

  Therefore, the bending moment M generated in the arbitrary cross section of the semicircular portion is expressed by the following equation (4).

In the upper equation (4), the maximum value of the bending moment, M _max, occurs at cos α = 0, that is, α = π / 2. Its cross-section is a CD cross-section of the action of pulling force P, the bending moment is the maximum value M _max, and this M _max is as the following equation (5).

Here, A is a cross-sectional area, and κ is a cross-sectional coefficient. Next, the stress generated in the hanging metal fitting 10 is obtained. For the semicircular curved portion of the hanging metal fitting 10, the stress σ _y is expressed by the following equation (6).

  By substituting equation (4) into equation (6) and then giving a required value to y, the stress at the specified position can be calculated.

For example, σ _CD in the CD cross section of FIG. 4 can be obtained by the following equation (7) when the bending moment M = M _max and the axial force Q = 0.

  In addition, the section coefficient κ of the bent bar in the equations (6) and (7) is given as in the equation (7) for a circular cross-section bar.

Where y is the distance from the neutral axis of the section of the bent bar
r: the radius of curvature of the bending rod. Next, in the above equation (8), if y = e (distance to the outer surface) is set, the stress σ _{CD out} on the outside of the CD cross section can be obtained, and y = −e (distance to the inner surface) is set. Stress σ _{CD in} on the inside of the CD cross section can be obtained.

In addition, since the fixed bending moment M ₀ and the axial force Q = P / 2 are applied to the linear portion of the hanging metal fitting 10, the stress is expressed by the following equation (9).

In equation (9), if y = e, the stress σ _{AB out} on the outside of the AB cross section can be obtained, and if y = −e, the stress σ _{AB in} on the inside of the AB cross section can be obtained.

  By the way, the elliptical cross section in which the major axis of the elliptical section of the section coincides with the direction of the acting force has the same section coefficient κ as the circular section, and the stress due to bending is circular as is apparent from the equation (7). Compared to the cross section, the size is in inverse proportion only to the cross sectional area.

  As apparent from the equation (2), the axial force Q is zero in the CD cross section shown in FIG. Therefore, only the bending stress due to the bending moment occurs in the CD cross section shown in FIG. 4, and the value is a value inversely proportional to the cross sectional area when the cross section is a circular cross section and an elliptical cross section.

  Consider the conventional hanging metal fitting 10 having specific dimensions shown in FIG.

  This hanging metal fitting 10 is conventionally used as the hanging metal fitting 10 for the above-described scale transport bucket 100 (up to 3 tons of suspension load). It fits the hook of an overhead crane with a lifting load of 10 tons. This hanging metal fitting 10 is an inverted U-shaped hanging metal fitting in which two parallel straight bars 11 and a semicircular curved portion 14 having a center radius of 130 mmR are connected. The whole is made of round steel with a uniform thickness of 75 mmφ, the distance between the straight bars is 185 mm, and the length of the straight bars is 280 mm.

Radius of semicircular curved part r = 13cm
Length of straight part l = 28cm
Hanging bracket diameter d = 7.5cm
Then,
Fixed bending moment M ₀ = (P / 2) × 13 × 13 × (2-π) / (56 + 13π)
= -0.99 × P
Maximum bending moment M _max = (P / 2) × 13 × (56 + 26) / (56 + 41)
= 5.49 x P
Bending moment at α = 45 ° M ₄₅ = M0 + (P / 2) r × 0.707
= 3.61 × P
Section coefficient κ = 0.0216 of bent bar
It is. The stress at the cross-section CD (α = 90 °) is σ _{CD in} = −0.17 × P
σ _{CD out} = 0.109 × P
The stress at α = 45 ° is σ _{45 in} = −0.09 × P
σ _{45 out} = 0.094 × P
The stress in the cross section AB (α = 0 °) is σ _{AB in} = −0.013 × P
σ _{AB out} = 0.035 × P
It is.

In the hanging metal fitting 10 of the embodiment, the cross section in the cross section CD is elliptical, but has a major axis having the same dimension as that of the circular cross section in the load direction. Therefore, the cross section coefficient κ is equal to the cross section coefficient of the circular cross section. Further, since the axial force Q does not act on the cross section CD and only the bending moment M _max acts, the values of stress when the σ _{CD in} and σ _{CD out} are changed to the circular cross section and the elliptical form are the cross sectional areas. It is only the effect of the difference.

If the minor axis of the elliptical cross section is now 60% of the major axis (in the specific embodiment described above, the minor axis of the elliptical cross section of the hanging bracket of the embodiment is 45 mm compared to the diameter of the original hanging bracket 10). ), The stress in the cross section CD (α = 90 °) is σ _{CD in} (ellipse) = − 0.28 × P
σ _{CD out} (ellipse) = 0.18 × P
It becomes. Incidentally, if the maximum suspension load P = 30 kN, σ _{CD in} = −5.1 kN / cm ²
σ _{CD out} = 3.27 kN / cm ²
σ _{CD in} (ellipse) = − 8.4 kN / cm ²
σ _{CD out} (ellipse) = 5.4 kN / cm ²
And the safety factor is at least 5 or more.

  The minor axis dimension of the elliptical cross section 13 is smaller than the opening dimension of the small crane hook 25 as shown in FIG. 3, and the suspension fitting 10 can be easily engaged with the crane hook 25.

It is a side view of the hanging metal fitting of the Example of this invention. It is an AA arrow line view of Fig.1 (a). It is explanatory drawing which shows engagement with the crane hook of the hanging metal fitting of an Example. It is explanatory drawing which shows engagement with the crane hook of the hanging metal fitting of an Example. It is explanatory drawing of the dynamic consideration of a hanging metal fitting. It is a side view of the scale conveyance bucket to which the present invention is applied. It is a front view of a hanging part. It is a side view of the scale conveyance bucket which shows an unloading attitude | position. It is a side view of the scale conveyance bucket which shows the process from an unloading attitude | position to a return attitude | position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hanging bracket 11 Straight bar 13 Circular cross section 14 Semicircular curved part 21, 25 Crane hook 22, 26 Opening part 23, 27 Rope 100 Scale conveyance bucket 101 Box 102 Pin 103 Protrusion 104 Bottom board 105 Slope board 106 Ground 110, 110a, 110b Lifter 111 Engagement hole (long hole)
112 Fork 115, 116 Arrow

Claims (1)

Can be shared by multiple types of large and small crane hooks, has an inverted U-shape with two parallel straight bars and a semi-circular curved part, and a crane hook inside the inverted U-shaped curved part In the hanging bracket that is pulled up in the direction of the straight bar by the crane hook ,
The upper end of the inverted U-shaped curved portion has an elliptical cross section ,
The major axis direction of the elliptical cross section is a direction parallel to the straight bar,
The short dimension of the elliptical cross section is made smaller than the opening dimension of the crane hook having the smallest opening dimension among the large and small types of crane hooks, and the short dimension of the elliptical cross section is the smallest. It can pass through the opening of the crane hook,
Increasing the dimension of the major axis of the elliptical cross section than the opening dimension of the crane hook having the smallest opening dimension among the large and small types of crane hooks,
The suspension bracket , wherein the portion other than the upper end of the curved portion has a circular cross section having the same diameter as the major axis of the elliptical cross section .

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