JPH07112919B2 - Tow hoist - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tow hoist.

[0002]

2. Description of the Related Art In a tow hoist for hoisting a load chain suspended on a load sheave by manually operating a lever or the like, if it is attempted to downsize the tow hoist, the load sheave and the hoist The number of oval links on the matching load chain
It is advantageous to reduce the corresponding number of meshes when the load sheave is regarded as a gear. This is because if the reduction gear groups in the towing hoist have the same reduction ratio,
This is because the reduction ratio can be increased as the number of links of the links is reduced.

Therefore, a load sheave in a conventional small-sized tow hoist has a structure as shown in FIGS.
The number of crossings of the first link c ... And the second link d ... Of the load chain b with respect to the load sheave a is minimized.

That is, the load sheave b has a shallow concave recess portion e with which the first link c abuts when lying down, and a deep concave portion with which one long side portion f ₁ thereof abuts when the second link d is upright. It had three places g and three places.

[0005]

If the rotational position of the load sheave b having such a conventional structure is, for example, the position shown in FIG. 10, the load sheave b is suspended from the first link c _{1 at} the upper left of FIG. Even if a load (load) F ₁ is applied to the first link c ₁ via the second link d ... And the first link c ..., the entire first link c ₁ is supported by the concave recess portion e of the load sheave b. .

Therefore, when an excessive load F ₁ that exceeds the strength of the load chain b is applied, the first link c
Both long side parts f ₁ and f ₂ of either the second link d ... Or the first link c ... Suspended from ₁ are broken as indicated by symbols h and h.

However, when the load sheave b reaches the rotational position shown in FIG. 11, the load F ₂ (75% of the load F _{1 in} FIG. 10) smaller than the load F ₁ causing the load chain b to break in FIG.
), One long side portion f ₁ of the second link d _{1 on} the upper left of the figure.
There is a problem in that a breakage occurs at a portion i that starts to bend from.

Since the circular arc portion j of the second link d ₁ is a free end without being supported by the load sheave b, shearing force indicated by arrows k and k acts on the portion i. It is considered that the arcuate portion j is in a state of a cantilever beam with the end portion m of the recess g as a fulcrum, and a bending moment of (length n) × (load F ₂ ) acts. (At this time, the other long side portions f ₂ are in an idle state with almost no stress.)

Therefore, an object of the present invention is to provide a tow hoisting machine that solves the above problems.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a large number of first and second links in order so that an oval first link and an oval second link are adjacent to each other. In a tow hoist equipped with a load chain connected to each other and a load sheave that suspends and rotates the load chain, the load sheave has a short axis of the first link that rotates the load sheave. The first link abuts so as to be parallel to the axial center, and one long side portion of the second link is in contact so that the minor axis of the second link is orthogonal to the rotational axis of the load sheave. A sheave body portion that is in contact with the sheave body portion, and the sheave body portion is protruded from the sheave body portion in the outer diameter direction and inserted into the first link. And a load receiving and supporting portion that abuts against each other.

Further, on the plane including the long axes of the first and second links of the load chain suspended on the load sheave, the length from the center point of the load sheave to the outer end of the load bearing portion is measured. , The radius of curvature of the arc contacting surface of the load bearing portion is equal to or greater than the distance from the midpoint of the elliptical diameter of the first link to the center point, and the curvature of the arc portion of the second link on the outer diameter side It is almost the same as the radius.

Further, on the plane including the long axes of the first and second links of the load chain suspended on the load sheave, the length from the center point of the load sheave to the outer end of the load bearing portion is The radius of gyration of the load chain is substantially the same.

Further, the ratio of the cross-sectional area of the load bearing portion to the cross-sectional area of the first link on the plane including the short axis and the long axis of the first link of the load chain suspended on the load sheave exceeds 0.7. It is less than 1.5.

Further, the radius of curvature of the arc contact surface of the load bearing portion on the plane including the short axis and the long axis of the first link of the load chain suspended on the load sheave is substantially the same as the radius of curvature of the second link. Is.

[0015]

With the rotation of the load sheave, the load bearing portion becomes horizontal, and even if a vertical load is applied to the arc portion near the one long side of the second link by the arc portion of the first link, Since the load bearing portion abuts along the outer diameter side peripheral surface near the one long side of the arc portion of the second link, the load is supported by the load bearing portion, and the arc portion of the second link is sheared. No force or bending moment is generated.

[0016]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments.

1 and 2 show an embodiment of a tow hoisting machine according to the present invention. A load chain 2 having a load hook 1 attached to one end (downward in the drawing) and a load chain 2 are suspended. And a cylindrical load sheave 3 that rotates.

The load sheave 3 is rotatably pivotally attached to the side plates 4 and 4 to which the upper hook 9 is attached, and is rotatably fitted on the shaft 5. A gear box 6 is fixed to one side plate 4, and a ratchet cover 7 is fixed to the other side plate 4.

A reduction gear group or the like is provided inside the gear box 6, and the shaft 5 and the load sheave 3 are interlockingly connected via the reduction gear group or the like. And the manual lever 8
The shaft 5 is configured to rotate in a predetermined direction by the swinging operation. Reference numeral 10 is a switching lever for rotating the shaft 5.

The rotation of the shaft 5 causes the load sheave 3 to rotate in a predetermined direction via the reduction gear group and the like, and the load chain 2 suspended on the load sheave 3 is wound up.
It is unwound.

However, as shown in FIGS. 3 and 4, the load chain 2 has a large number of first and second links 11 so that the first link 11 and the second link 12 are hooked next to each other. It is composed of 12 ... 3 shows the YY cross section of FIG. 4, and FIG. 4 shows the XX cross section of FIG.

The first link 11 and the second link 12 are made of the same material, shape and structure, and both 11 and 12 are oblong with each short side of the rectangle being a semicircle. It is composed of long side portions 13a, 13b and arc portions 14a, 14b which are integrally formed with a solid axis in cross section. The outer diameter of this circular cross section is uniform in the axial direction of the solid shaft.

Further, as shown in FIGS. 3 to 6, the load sheave 3 has a central hole through which the shaft 5 (see FIG. 1) is inserted.
A sheave body 15 having 19 and three radial load bearing portions 16 are integrally formed. As the material of the load sheave 3, for example, alloy steel such as SCM435 or S45C is used.

The sheave body 15 has a short axis A of the first link 11.
Shallow recessed portion 17 wherein the first link 11 is in contact in a state in _{which 1} is face down so that the load sheave 3 the rotation axis C and parallel to form
When the second link 12 is erected such that the minor axis A ₂ of the second link 12 is orthogonal to the rotational axis C of the load sheave 3, the outer peripheral surface of the one long side portion 13a thereof abuts. Deep recess 18
And three are respectively provided, and the second link 12 is prevented from collapsing by the pair of three-pronged flanges 20 and 20.

Here, the "minor axis A ₁ " is an axis which passes through the elliptical center E ₁ of the first link 11 and is orthogonal to the axes of the long side portions 13a, 13b of the first link 11, Axis A ₂ "is the second link 12
Passing through the midpoint E ₂ of the elliptical diameter of
It is an axis orthogonal to the axis of b.

Therefore, when the load sheave 3 rotates, the first link 11 and the second link 12 are respectively inserted into the concave recess 17 and the recess 18.
However, the load chain 2 is hoisted and hoisted by successively unhooking.

The load bearing portion 16 is provided so as to project from the center of the concave recess portion 17 in the outer diameter direction, is inserted into the first link 11, and is close to the long side portion 13a of the arc portion 14a of the second link 12. It is configured to abut along the outer diameter side peripheral surface of the.

Therefore, the load sheave 3 is at the rotational position shown in FIG. 4, and is suspended from the second link 12a at the upper left of FIG. 4 via the first link 11 ... And the second link 12 ... A load (load) as a tensile force directed downward in the figure at a portion J where the long link portion 13a begins to bend from the long side portion 13a.
Even if F is applied, the outer peripheral surface of the one long side portion 13a abuts on the recess 18, and the outer peripheral surface of the portion J abuts on the arcuate portion contact surface 22 of the load bearing portion 16, so that the portion Shear force and bending moment are not generated in J, and the load F can be supported by the load sheave 3.

When an excessive load F that exceeds the strength of the load chain 2 is applied, the first link 11 and the second link 12 are suspended from the second link 12a at the upper left of FIG. Either of the long side portions 13a and 13b is broken, for example, as shown by symbols S and S.

Further, when the load sheave 3 is in a position other than the rotation position shown in FIG. 4, for example, in the rotation position shown in FIG. 7, the second link 12 is suspended from the first link 11a at the upper left of FIG. Even if a load F is applied to the first link 11a via the first link 11 ..., the whole of the first link 11a is supported by the recessed portion 17 of the sheave body 15, so that there is no problem of generation of shearing force or the like. When an excessive load F that exceeds the strength of the load chain 2 is applied, the second link 12 suspended from the first link 11a and the first link 11
Both long side portions 13a and 13b of either of the ...
It fractures as shown by S.

However, in order to reliably prevent the generation of the shearing force and the bending moment at the portion J of the second link 12a as described above in the state shown in FIG. 4, the following is performed.

That is, the long axes B ₁ of the first and second links 11, 12 of the load chain 2 suspended on the load sheave 3 are ...
The center point G of the load sheave 3 on the plane including B ₂ ...
From to the outer end 21 of the load bearing branch 16 the length L _1, to the distance L ₂ or more to the center point G from the oval-diameter point E ₁ of the first link 11.

If the length L ₁ is smaller than the distance L ₂ ,
This is because the range in which the load bearing portion 16 contacts the portion J of the second link 12a becomes extremely small, and it becomes difficult to prevent the generation of shearing force and bending moment.

Here, the "major axis B ₁ " passes through the elliptical center E ₁ of the first link 11 and the long side portions 13a, 13b of the first link 11 are connected.
Is the axis parallel to the axis center of, and the "long axis B ₂ " is the second link
The long side portion 13 of the second link 12a passes through the midpoint E ₂ of the elliptical diameter of 12a.
It is an axis parallel to the axes of a and 13b.

The optimum condition for this length L ₁ is that it is substantially the same as the radius of gyration R of the load chain 2,
Under this condition, it is possible to reliably prevent the generation of shearing force and bending moment.

When the length L ₁ becomes longer than the turning radius R,
This is because the load bearing portion 16 projects too much, and it becomes difficult to hang the load chain 2 on the load sheave 3.

Here, the "turning radius R" is the first and second links 1 of the load chain 2 suspended on the load sheave 3.
It is the radius of the pitch circle diameter D ₁ that connects the center points T of the transverse sections of the first links 11 on the plane including the long axes B ₁ and B ₂ of ₁ and 12.

The radius of curvature R ₁ of the arcuate contact surface 22 of the load bearing portion 16 on the plane including the major axes B _1, ..., B ₂ ... The radius of curvature R _{2 on} the outer diameter side is substantially the same.

When the difference between the radii of curvature R ₁ and R ₂ becomes large,
This is because the arcuate part contact surface 22 and the arcuate part 14a locally contact each other, and the load F tends to concentrate on the contact part, which may cause damage.

Further, as shown in FIG. 3, the load sheave 3
Axis A of the first link 11 of the load chain 2 suspended on the
The ratio K ₁ / K ₂ of the cross-sectional area K ₁ of the load bearing portion 16 and the cross-sectional area K ₂ of the first link 11 on a plane including ₁ and the long axis B _1.
To 0.7 <K ₁ / K ₂ <1.5. Preferably 1.0 <
K ₁ / K ₂ <1.2.

If K ₁ / K ₂ is smaller than this range, the strength of the load receiving portion 16 is insufficient, and if K ₁ / K ₂ is larger than this range, it becomes difficult to hang the load chain 2 on the load sheave 3. is there.

Further, the radius of curvature R ₃ of the arcuate portion contact surface 22 of the load bearing portion 16 on the plane including the minor axis A ₁ and the major axis B ₁ is made substantially the same as the radius of curvature R ₄ of the second link 12. To do.

When the difference between the radii of curvature R ₃ and R ₄ becomes large,
This is because the arcuate part contact surface 22 and the arcuate part 14a locally contact each other, and the load F tends to concentrate on the contact part, which may cause damage.

However, in the prior art, the second link d ₁ was broken by the force of 6440 kgf in the state of FIG. 11, but in the present invention, the force of 6440 kgf is applied to the second link 12a in the state of FIG. The second link 12a is not broken at all, and with a force of 8600 kgf.
It was confirmed that the other link, which was suspended from, was broken. Note that this data is for the case where the diameter (shaft diameter) of the cross section of the links c, d, 11, 12 is 7.1 mm in both FIG. 11 and FIG.

The present invention is not limited to the above-mentioned embodiments, and design changes can be freely made without departing from the gist of the present invention. For example, the load bearing portion 16, the recessed portion 17 and the recessed portion 18 may be formed in the load sheave 3 having three or more places, respectively.

[0046]

Since the present invention is constructed as described above, it has the following great effects.

According to the towing and hoisting machine of claim 1, no matter what rotational position the load sheave 3 is, shearing force and bending moment are not generated in the arc portion 14a of the second link 12 of the load chain 2. Therefore, the limit load until the load chain 2 is broken becomes constant.

Therefore, if the hoist has the same size as the conventional one, the allowable value of the working load can be increased. On the contrary, if the allowable value of the working load is the same as the conventional one, the chain can be made thinner than the conventional one, and accordingly, the load sheave can be downsized and the overall size can be reduced.

According to the towing and hoisting machine of the second aspect, the arcuate portion 14a of the second link 12 is surely and uniformly contacted with the arcuate portion contact surface 22 of the load bearing portion 16 to generate shearing force and bending moment. Can be reliably blocked. Further, it is possible to prevent the load chain 2 from coming off the load sheave 3.

According to the towing and hoisting machine of the third aspect, the load receiving portion 16 has an appropriate amount of protrusion so that the generation of the shearing force and the bending moment can be reliably prevented, and the load chain 2 is attached to the load sheave 3. You can smoothly hang it.

According to the towed hoisting machine of the fourth aspect, the load bearing portion 16 can be made to have sufficient strength to resist the load F, and the load bearing portion 16 with respect to the axial thickness of the link 12 can be used. Has a moderate thickness, and the load chain 2 can be smoothly hooked and unhooked on the load sheave 3.

According to the towing and hoisting machine of the fifth aspect, the arcuate portion 14a of the second link 12 comes into contact with the arcuate portion contact surface 22 of the load bearing portion 16 surely and uniformly to generate a shearing force and a bending moment. Can be reliably blocked.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a side view.

FIG. 3 is a sectional front view showing a state in which a load chain is suspended on a load sheave.

FIG. 4 is a sectional side view showing a state in which a load chain is suspended on a load sheave.

FIG. 5 is a front view of a load sheave.

FIG. 6 is a sectional side view of a load sheave.

FIG. 7 is a cross-sectional side view illustrating the operation.

FIG. 8 is a front view showing a conventional load sheave.

FIG. 9 is a side view showing a conventional load sheave.

FIG. 10 is a sectional side view showing a state where the load chain is suspended on the load sheave.

FIG. 11 is a sectional side view showing a state in which a load chain is suspended on a load sheave.

[Explanation of symbols]

2 Load chain 3 Load sheave 11 First link 12 Second link 13a Long side part 14a Arc part 15 Sheave body part 16 Load bearing part 21 Outer end 22 Arc part abutment surface A ₁ Short axis A ₂ Short axis B ₁ Long axis B ₂ major axis C axis of rotation D ₂ radius of gyration E ₁ elliptical center point G center point L ₁ length L ₂ distance K ₁ cross section K ₂ cross section

Claims (5)

[Claims] 1. A large number of the first and second links 11 ..., so that the elliptical first link 11 and the elliptical second link 12 are adjacent to each other.
In a traction hoisting machine equipped with a load chain 2 formed by sequentially connecting 12 ... And a load sheave 3 that rotates by suspending the load chain 2, the load sheave 3 is the first link 11 The short axis A ₁ of the load sheave 3 is the axis of rotation C of the load sheave 3.
The first link 11 abuts so as to be parallel to the first link 11, and one of the second links 12 is arranged so that the minor axis A ₂ of the second link 12 is orthogonal to the rotation axis C of the load sheave 3. Long side
The sheave body portion 15 with which 13a abuts, and the long side portion 13a of the arc portion 14a of the second link 12 which is projected from the sheave body portion 15 in the outer diameter direction and inserted into the first link 11.
A traction hoisting machine comprising: a load bearing portion (16) that abuts along the outer diameter side peripheral surface. 2. A center point G of the load sheave 3 on a plane including the long axes B ₁ and B ₂ of the first and second links 11 and 12 of the load chain 2 suspended on the load sheave 3. The length L ₁ from the load bearing portion 16 to the outer end 21 of the load bearing portion 16 is the above first link.
When the distance L ₂ from the ellipse midpoint E _{1 of} 11 to the center G is not less than the radius of curvature R ₁ of the arc contact surface 22 of the load bearing portion 16 is equal to the arc portion of the second link 12. The traction hoisting machine according to claim 1, which has a radius of curvature R _{2 on} the outer diameter side of 14a. 3. A center point G of the load sheave 3 on a plane including the major axes B ₁ , B ₂ of the first and second links 11, 12 of the load chain 2 suspended on the load sheave 3. load bearing up to the outer end 21 of the branch 16 length L ₁ is the radius of rotation D ₂ and traction hoist according to claim 1 or claim 2, wherein substantially the same of the load chain 2 from. 4. The cross-sectional area K ₁ of the load bearing portion 16 on a plane including the short axis A ₁ and the long axis B ₁ of the first link 11 of the load chain 2 suspended on the load sheave 3 and the first link.
The traction hoisting machine according to claim 1, claim 2 or claim 3, wherein the ratio K ₁ / K ₂ to the cross-sectional area K _{2 of} 11 is more than 0.7 and less than 1.5. 5. The radius of curvature R of the arc contact surface 22 of the load bearing portion 16 on a plane including the short axis A ₁ and the long axis B ₁ of the first link 11 of the load chain 2 suspended on the load sheave 3. ₃ claim 1 are substantially the same radius of curvature R ₄ of the second link 12, claim 2, claim 3 or claim 4 traction hoist according.