Chain block

Abstract

Provided is a chain block comprising a chain block body having a bearing fitting portion into which a bearing can be fitted without requiring machining on a butt joint surface between frames.　A chain block 10 comprises a chain block body CB1 constituted by sequentially stacking a first die-cast frame 11, a second die-cast frame 12, and a third die-cast frame 13, which are formed by aluminum die casting. The first die-cast frame 11, the second die-cast frame 12, and the third die-cast frame 13 are provided with bearing fitting portions 11a7, 11b3, 11b4, 12b3, 13a3, 13a4 into which bearings B1 to B6 can be fitted.

Description

Chain block

[0001] The present invention relates to a chain block.

[0002] For example, as shown in Patent Document 1, there is a chain block in which the chain block body is composed of two separate box-shaped frames (2, 11). Patent Document 1 discloses that the box-shaped frames (2, 11) are formed, for example, from aluminum die-casting.

[0003] Another example of a chain block is the configuration shown in Patent Document 2. In Patent Document 2, the chain block body is configured such that each member is supported by a pair of frames (540, 540') formed from steel plates.

[0004] Utility Model Publication No. 56-40787 Publication No. CN104760898A

[0005] In the configuration of Patent Document 1, the frame is a two-piece aluminum die-cast structure, resulting in large uneven portions on the box-shaped frame (2, 11). Therefore, when molten metal is poured into the mold and solidifies, the precision of the butt joint between the two box-shaped frames (2, 11) is reduced due to shrinkage and other factors, requiring additional machining. Furthermore, in order to facilitate demolding, the mold must have a large draft angle for removing the box-shaped frame (2, 11).

[0006] The configuration disclosed in Patent Document 2 is a manual chain hoist having a main body (500) that combines a steel plate frame as a reinforcing frame, an aluminum die-cast gearbox (530), and symmetrical frames (540, 540') made of engineering plastic as a chain guide. This configuration also has the problem of a complex frame structure, including the need for a reinforcing plate (560) with multiple bearing holes.

[0007] The present invention has been made in consideration of the above circumstances, and has as its object to provide a chain block having a chain block body with a bearing fitting portion into which a bearing can be fitted without requiring machining of the mating surfaces of the frames.

[0008] In order to solve the above-mentioned problems, according to a first aspect of the present invention, there is provided a chain block for lifting and lowering loads, characterized in that it has a chain block body constructed by stacking in order a first die-cast frame, a second die-cast frame, and a third die-cast frame formed by light alloy die-casting, and the first die-cast frame, the second die-cast frame, and the third die-cast frame are provided with bearing fitting portions into which bearings can be fitted.

[0009] According to the present invention, it is possible to provide a chain block having a chain block body with a bearing fitting portion into which a bearing can be fitted, without requiring machining of the mating surfaces of the frames.

[0010] 7 is a perspective view showing the configuration of a chain block according to an embodiment of the present invention. FIG. 1 is an exploded perspective view showing the configuration of the chain block shown in FIG. 1. FIG. 2 is a front view showing the configuration of the chain block shown in FIG. 1. FIG. 3 is a cross-sectional view showing the chain block cut along line 1-1 in FIG. 3. FIG. 4 is a cross-sectional view showing the chain block cut along line 2-2 in FIG. 3. FIG. 4 is a cross-sectional view showing the chain block cut along line 2-2 in FIG. 3. FIG. 5 is a perspective view showing the configuration of a first frame included in the chain block shown in FIG. 1, as seen from the side where a hand wheel is attached. FIG. 6 is a view showing the first frame included in the chain block shown in FIG. 1, as seen from the opposite side to FIG. 7. FIG. 7 is a partial cross-sectional view showing the configuration near the bolt insertion holes of the first to third frames in the chain block shown in FIG. 1. FIG. 8 is a view showing the second frame included in the chain block shown in FIG. 1, as seen from the side where a hand wheel is arranged. FIG. 9 is a view showing the second frame included in the chain block shown in FIG. 1, as seen from the opposite side to FIG. 9. FIG. 10 is a view showing the third frame included in the chain block shown in FIG. 1, as seen from the side where a hand wheel is arranged.

[0011] A chain block 10 according to an embodiment of the present invention will now be described with reference to the drawings.

[0012] In the following description, the X direction is the axial direction of the drive shaft 40, the X1 side is the side where the wheel cover 15 is located in Figure 2, and the X2 side is the opposite side where the third die-cast frame 13 is located. The Z direction is the vertical direction (hanging direction; hoisting / lowering direction) when the chain block 10 is suspended, the Z1 side is the upper side in the suspended state, and the Z2 side is the lower side in the suspended state. The Y direction is the direction perpendicular to the X and Z directions, the Y1 side is the lower right side in Figure 2, and the Y2 side is the opposite upper left side.

[0013] FIG. 1 is a perspective view showing the configuration of a chain block 10 according to this embodiment. FIG. 2 is an exploded perspective view showing the configuration of the chain block 10 shown in FIG. 1. FIG. 3 is a front view showing the configuration of the chain block 10 shown in FIG. 1. FIG. 4 is a cross-sectional view showing the chain block 10 taken along line 1-1 in FIG. 3. FIG. 5 is a cross-sectional view showing the chain block 10 taken along line 2-2 in FIG. 3. FIG. 6 is a cross-sectional view showing the chain block 10 taken along line 2-2 in FIG. 3.

[0014] 1 to 6, the chain block 10 includes a first die-cast frame 11, a second die-cast frame 12, a third die-cast frame 13, an upper hook 20, a hand wheel assembly 30, a drive shaft 40, a brake mechanism 50, a load sheave shaft 80 having a load sheave 84, a hand chain C1, a load chain C2, etc. These components are assembled to form a chain block main body CB1.

[0015] (1-1. Overview of the First Die-Casting Frame 11, the Second Die-Casting Frame 12, and the Third Die-Casting Frame 13) The first die-casting frame 11, the second die-casting frame 12, and the third die-casting frame 13 are formed by light alloy die-casting, such as aluminum die-casting, which uses an aluminum-based metal. Other examples of light alloy die-casting include magnesium die-casting, which uses a magnesium-based alloy. The first die-casting frame 11, the second die-casting frame 12, and the third die-casting frame 13 may also be formed by light alloy die-casting, using a light metal such as magnesium, other than light alloy die-casting.

[0016] In the following description, for the sake of simplicity, the first die-casting frame 11 will be referred to as the first frame 11, the second die-casting frame 12 as the second frame 12, and the third die-casting frame 13 as the third frame 13.

[0017] The first frame 11, second frame 12, and third frame 13 support the various components of the chain block 10. The first frame 11, second frame 12, and third frame 13 are fastened together with bolts BT and nuts N1. A connecting shaft 14 is attached to the first frame 11 and the third frame 13. An upper hook 20 for hanging the chain block on, for example, a ceiling is pivotally attached to the connecting shaft 14. The tension of the load applied to the load chain C2 is transmitted to the load sheave shaft 80 via a load sheave 84 (described later), and then to the upper hook 20 via the first frame 11 and the third frame 13, which pivotally support the load sheave shaft 80.

[0018] (1-2. Regarding the Wheel Cover 15, etc.) A wheel cover 15 that houses the hand wheel assembly 30 is attached to one side (X1 side) in the axial direction (X direction) of the first frame 11. This wheel cover 15 is a part that covers the hand wheel assembly 30 to prevent the hand chain C1 from falling off and to protect it from the outside, and is provided in the shape of a cylinder with a bottom.

[0019] The wheel cover 15 is attached to the first frame 11 by a support plate 16. The support plate 16 engages a folded portion 15a of the wheel cover 15 but does not fix the wheel cover 15. Therefore, the wheel cover 15 is rotatable between the first frame 11 and the support plate 16. The folded portion 15a is arranged to fit into an annular recess 11a4 of the first frame 11 between an outer peripheral wall 11a2 and an inner peripheral rib 11a3, which will be described later.

[0020] A pair of protective members 17 made of resin are attached to the wheel cover 15 to protect the hand chain C1 and the wheel cover 15.

[0021] (1-3. Handwheel Assembly 30) Next, we will explain the handwheel assembly 30. The handwheel assembly 30 includes a handwheel 31, which has an insertion hole 31a at the center of the handwheel 31. A wheel plate portion 31b is provided around the insertion hole 31a.

[0022] An overload prevention mechanism 33 including a pair of clutch plates 33a, 33b and a drive member 33c is disposed in the insertion hole 31a. Furthermore, a female thread portion 33c1 having a female thread is provided at the radial center of the drive member 33c. The rotational force from the hand wheel 31 is transmitted to the drive shaft 40 via the overload prevention mechanism 33, and in the event of an overload, slippage occurs between the wheel plate portion 31b and the clutch plates 33a, 33b, protecting the suspended load and the chain block 10 from the overload.

[0023] (1-4. Regarding the drive shaft 40) Next, the drive shaft 40 will be described. As shown in Figures 2 to 5, the drive shaft 40 is a member that extends in the X direction from the second frame 12 to the hand wheel 31. The drive shaft 40 is provided with a male threaded portion 41. The male threaded portion 41 is the portion into which the female threaded portion 33c1 of the drive member 33c described above is screwed.

[0024] A flange portion 42 is provided on the drive shaft 40 on the X2 side of the male thread portion 41 in the axial direction (X direction), and this flange portion 42 is capable of receiving a brake plate 52, which will be described later.

[0025] Furthermore, a first bearing attachment portion 44 is provided on the drive shaft 40 on the other side (X2 side) in the axial direction (X direction) of the flange portion 42. The first bearing attachment portion 44 is a portion for supporting the drive shaft 40 relative to the first frame 11 via a bearing B1. The attachment of the bearing B1 to the first frame 11 will be described later.

[0026] A second bearing attachment portion 45 is provided at the other axial end (X-direction) (the end on the X2 side) of the drive shaft 40. The second bearing attachment portion 45 is a portion for supporting the drive shaft 40 relative to the second frame 12 via a bearing B2. The attachment of the bearing B2 to the second frame 12 will also be described later.

[0027] A pinion gear 46 is provided on the drive shaft 40 between the first bearing attachment portion 44 and the second bearing attachment portion 45. This pinion gear 46 is the portion that meshes with a large-diameter gear 63 (described later) of the first reduction gear section G1. Therefore, the drive shaft 40 is the shaft of the hand wheel assembly 30, and is the input shaft of the first reduction gear section G1 (reduction gear mechanism) to which the rotational driving force of the hand wheel 31 is input.

[0028] (1-5. Brake Mechanism 50) A brake mechanism 50 is also attached to the drive shaft 40. The brake mechanism 50 mainly comprises brake plates 51 and 52, a ratchet wheel 53, and a pawl member 54. The ratchet wheel 53 is disposed between the brake plates 51 and 52, and the brake plates 51 and 52 and the ratchet wheel 53 are disposed between the drive member 33c and the flange 42. When the hand wheel assembly 30 is rotated in the winding direction by pulling the hand chain C1 in the winding direction, the rotation in the winding direction causes the drive member 33c to move in a direction that presses against the brake plate 52 due to the action of the female thread portion 33c1 and the male thread portion 41. As a result, the rotational force of the hand wheel assembly 30 is transmitted to the flange 42 via the brake plate 52, ratchet wheel 53, and brake plate 51. As the hand wheel assembly 30 rotates, the drive shaft 40 also rotates integrally.

[0029] The ratchet wheel 53 is rotatably mounted on the drive shaft 40. The teeth of the ratchet wheel 53 are engaged with the tip of a ratchet member 54 shown in Figure 2, and this engagement forms a ratchet mechanism that prevents the ratchet wheel 53 from rotating in the reverse direction (rotating in the winding-down direction).

[0030] On the other hand, when the hand wheel assembly 30 is rotated in the lowering direction by pulling the hand chain C1 in the lowering direction, the rotation in the lowering direction causes the drive member 33c to move in a direction that loosens the pressure on the brake plate 51. Then, even if the ratchet wheel 53 cannot rotate in the lowering direction, the pressure between the ratchet wheel 53 and the brake plates 51 and 52 is loosened, allowing the load sheave shaft 80, load gear 70, reduction gear member 60, and drive shaft 40, which will be described later, to rotate. If the pulling of the hand chain C1 in the lowering direction is stopped while a load is suspended, the load weight immediately causes the drive member 33c to press the brake plate 51 of the brake mechanism 50 against the ratchet wheel 53, activating the brake and holding the load.

[0031] (1-6. Reduction Gear Member 60 and Load Gear 70) Next, the reduction gear member 60 will be described. As shown in FIG. 6 , the reduction gear member 60 has a first bearing attachment portion 61, a second bearing attachment portion 62, a large-diameter gear 63, and a small-diameter gear 64. Of these, the first bearing attachment portion 61 is a portion located at one end (X1 side) of the reduction gear member 60 in the axial direction (X direction), and is a portion for supporting the reduction gear member 60 relative to the first frame 11 via a bearing B3. The attachment of the bearing B3 to the first frame 11 will be described later.

[0032] The second bearing attachment portion 62 is a portion located on the other end side (X2 side) of the reduction gear member 60 in the axial direction (X direction), and is a portion for supporting the reduction gear member 60 relative to the third frame 13 via a bearing B4. The attachment of the bearing B4 to the third frame 13 will be described later.

[0033] The large diameter gear 63 is a gear portion that meshes with the pinion gear 46 and constitutes the first reduction gear portion G1. The large diameter gear 63 is located in a gear box GB1. The large diameter gear 63 and the pinion gear 46 are set to reduce the rotational speed at a predetermined reduction ratio.

[0034] The small diameter gear 64 is a part that meshes with the load gear 70, and this meshing is set so that the small diameter gear 64 and the load gear 70 are reduced in speed at a predetermined reduction ratio.

[0035] Furthermore, the load gear 70 with which the small diameter gear 64 meshes has a center hole (reference numeral omitted), and this center hole and a gear mounting portion 81 of the load sheave shaft 80 described later are connected, for example, by a spline connection or other torque-transmitting connection structure, so that the two rotate integrally.

[0036] The second reduction gear section G2 is composed of the small diameter gear 64 and the load gear 70. The second reduction gear section G2 is housed in a gear box GB2 formed by the second frame 12 and the third frame 13 fixed to the second frame 12.

[0037] (1-7. Regarding the Load Gear 70) Next, the load sheave shaft 80 will be described. The load sheave shaft 80 has a gear mounting portion 81, a first bearing mounting portion 82, a second bearing mounting portion 83, and a load sheave 84. The gear mounting portion 81 is the portion that is coupled to the center hole of the load gear 70, thereby allowing the load gear 70 and the load sheave shaft 80 to rotate integrally.

[0038] The first bearing attachment portion 82 is a portion located on one end side (X1 side) in the axial direction (X direction) of the load sheave shaft 80. The first bearing attachment portion 82 is a portion for supporting the load sheave shaft 80 relative to the first frame 11 via a bearing B5. The attachment of the bearing B5 to the first frame 11 will be described later.

[0039] A second bearing attachment portion 83 is provided on the other end (X2 side end) in the axial direction (X direction) of the load sheave shaft 80. The second bearing attachment portion 83 is a portion for supporting the load sheave shaft 80 relative to the third frame 13 via a bearing B6. The attachment of the bearing B6 to the third frame 13 will also be described later.

[0040] The load sheave 84 is a portion around which the load chain C2 is looped, and has chain pockets (horizontal pockets and vertical pockets (not shown)) around its entire circumference into which the load chain C2 fits.

[0041] (2. Detailed Configuration of First Frame 11, Second Frame 12, and Third Frame 13) Next, detailed configurations of the first frame 11, second frame 12, and third frame 13 will be described. As described above, the first frame 11, second frame 12, and third frame 13 are formed by aluminum die-casting, and therefore have many irregularities compared to when a plate-like frame such as a steel plate is used. Detailed configurations of these first to third frames 11 to 13 will be described below.

[0042] In the following description, components that have not yet been described but are attached to the first to third frames 11 to 13 will also be described. To simplify the names, the surface of the third frame 11 on which the hand wheel 31 is disposed will be referred to as the "H surface 11a," and the opposite surface on which the reduction gear member 60 is disposed will be referred to as the "G surface 11b." Similarly, in the second frame 12, the surface facing the same direction as the H surface 11a will be referred to as the "H surface 12a," and the surface facing the same direction as the G surface 11b will be referred to as the "G surface 12b." In addition, in the third frame 13, the surface facing the same direction as the H surface 11a will be referred to as the "H surface 13a," and the surface facing the same direction as the G surface 11b will be referred to as the "G surface 13b."

[0043] (2-1. Regarding the first frame 11) Fig. 7 is a perspective view showing the configuration of the first frame 11 as viewed from the side where the hand wheel 31 is attached, and also shows some of the components attached to this first frame 11. Fig. 8 is a view showing the first frame 11 as viewed from the side where the reduction gear member 60 is arranged, and also shows some of the components attached to this first frame 11.

[0044] As shown in Figures 7 and 8, the first frame 11 has a configuration in which the configuration on the H surface 11a side on which the hand wheel 31 is arranged and the configuration on the G surface 11b side on which the reduction gear member 60 is arranged are integrated with a slight offset in the YZ plane.

[0045] The H-surface 11a side of this first frame 11 is provided with a bottom 11a1, an outer peripheral wall 11a2, an inner peripheral rib 11a3, an annular recess 11a4, a nut accommodating portion 11a5, a bolt insertion hole 11a6, a bearing fitting portion 11a7, and radial ribs 11a8.

[0046] The bottom 11a1 is a wide portion in a plane (YZ plane) perpendicular to the thickness direction (X direction) of the first frame 11, and a part of the bottom 11a1 is protruding or, conversely, recessed.

[0047] In this embodiment, the outer peripheral wall 11a2 is a non-circular annular outer wall (a quadrangle with curved sides) that is arranged to surround the inner peripheral rib 11a3. The first frame 11 has a lateral protrusion 11c that protrudes from the outer peripheral wall 11a2 toward the Y1 side, and this lateral protrusion 11c is used on the G surface 11b side as a portion for guiding the load chain C2 (details will be described later).

[0048] A portion of the outer peripheral wall 11a2 protrudes upward (toward the Z1 direction) (hereinafter, this portion will be referred to as an upward protrusion 11d). A connecting shaft hole 11e for inserting and supporting the connecting shaft 14 penetrates the upward protrusion 11d.

[0049] Here, a support plate 16 is attached to the end face of the outer peripheral wall 11a2 on the hand wheel 31 side (hereinafter, this end face will be referred to as the casting surface end face 11f). The casting surface end face 11f has the same surface roughness as when the first frame 11 was produced by aluminum die casting, and is not subjected to any machining such as cutting or grinding, which allows for a corresponding reduction in the number of processing steps. Note that not only the casting surface end face 11f, but also other portions of the first frame 11 are not subjected to any machining such as cutting or grinding, except for the removal of casting burrs and the like.

[0050] Furthermore, screw holes 11g are provided in the outer peripheral wall 11a2 at locations corresponding to the four corners in the YZ plane. The screw holes 11g are holes into which screws S1 (see FIG. 2) for fixing the support plate 16 are screwed.

[0051] The inner circumferential rib 11a3 protrudes from the bottom 11a1 and is provided inside the area surrounded by the outer circumferential wall 11a2. The inner circumferential rib 11a3 has a circular ring shape that is concentric with the bearing fitting portion 11a7. An annular recess 11a4 is provided between the inner circumferential rib 11a3 and the outer circumferential wall 11a2. When the folded portion 15a of the wheel cover 15 is positioned in the annular recess 11a4, the inner circumferential surface of the wheel cover 15 slides against the outer circumferential surface of the inner circumferential rib 11a3 (see FIG. 5 ). This allows the wheel cover 15 to absorb any impact that may be applied to the wheel cover 15.

[0052] The gap between the outer peripheral wall 11a2 and the inner peripheral rib 11a3 is set to be large enough to allow the folded portion 15a to fit therein.

[0053] The nut accommodating portion 11a5 is a portion for accommodating and supporting the nut N1 that threads onto the bolt BT. In this embodiment, a total of three nut accommodating portions 11a5 are provided, one of which is recessed from the protruding portion that protrudes from the bottom portion 11a1 surrounded by the inner peripheral rib 11a3. The remaining two are recessed from the lateral protrusions 11c.

[0054] As shown in Fig. 7, the nut accommodating portion 11a5 has a generally hexagonal appearance, and functions as a rotation stopper when the hexagonal nut N1 is fitted in. Note that, as shown in Fig. 5, the nut accommodating portion 11a5 is a stepped hole and has a step 11a51 that receives the nut N1.

[0055] The nut accommodating portion 11a5 communicates with the bolt insertion hole 11a6. Here, FIG. 9 shows cross-sectional shapes along the axes of the bolt insertion holes 11a6, 12a9, and 13a5 of the first frame 11, the second frame 12, and the third frame 13. As shown in FIG. 9, the bolt insertion hole 11a6 has a sloped portion 11a61 and a parallel portion 11a62. The sloped portion 11a61 is a sloped portion that facilitates removal of the bolt insertion hole 11a6 from a mold during production of the first frame 11 by aluminum die casting. The parallel portion 11a62 is a portion where the diameter of the hole portion does not change, but is located on the other axial side (X2 side) of the insertion hole 11a6 and is the smallest hole portion of the insertion hole 11a6. The gap (clearance) between this parallel portion 11a62 and the shaft portion of the bolt BT is set to be smaller than the gap between the bearing fitting portion 11a7 described below and other bearing fitting portions 11b3, 11b4, etc. and the outer shape of the bearing fitted into each bearing fitting portion.

[0056] Therefore, it is possible to position the first to third frames 11 to 13 by inserting a bolt BT into the bolt insertion hole 11a6 and then inserting this bolt BT into the bolt insertion hole 12a9 of the second frame 12 and the bolt insertion hole 13a5 of the third frame 13. The bolt insertion holes 11a6, 12a9, and 13a5 correspond to bolt holes.

[0057] The bearing fitting portion 11a7 is a portion into which the bearing B1 that supports the drive shaft 40 is fitted, and is recessed from the center of the inner peripheral rib 11a3 in the radial direction of the bottom portion 11a1. Therefore, the bearing fitting portion 11a7 has a step portion 11a71 that receives the bearing B1 and an insertion hole 11a72 through which the drive shaft 40 is inserted.

[0058] The radial ribs 11a8 protrude from the bottom 11a1 and are present in the annular recess 11a4 to improve the strength of the first frame 11, improve the flow of molten metal, and suppress deformation of the inner circumferential rib 11a3 due to tension on the outer circumferential wall 11a2 as it solidifies. Therefore, the radial ribs 11a8 are provided to connect the outer circumferential wall 11a2 and the inner circumferential rib 11a3. A plurality of radial ribs 11a8 are provided along a portion of the circumferential direction of the annular recess 11a4. However, because the folded portion 15a is located in the annular recess 11a4, the radial ribs 11a8 are provided lower than the protruding height of the outer circumferential wall 11a2 and the inner circumferential rib 11a3.

[0059] Additionally, an axial hole 11a9 into which a claw shaft, which is a rotation shaft of the pair of claw members 54, is inserted is also provided inside the bottom portion 11a1 surrounded by the inner peripheral rib 11a3.

[0060] As shown in FIG. 8, the G surface 11b side of the first frame 11 is provided with a bottom 11b1, an outer wall 11b2, a bearing fitting portion 11b3, a bearing fitting portion 11b4, a chain guide wall 11b5, a guide plate mounting portion 11b6, a stripper mounting portion 11b7, an arc guide accommodating portion 11b8, a nut accommodating portion 11b9, and radial ribs 11b10.

[0061] The bottom portion 11b1 is a portion corresponding to the back side of the bottom portion 11a1, but compared to the bottom portion 11a1, the G surface 11b has many irregularities and therefore has fewer flat portions.

[0062] The outer peripheral wall 11b2 is a wall portion that protects the various components arranged inside it from the outside, but the portion through which the load chain C2 is pulled out is appropriately cut out. The outer peripheral wall 11b2 has a first outer peripheral wall 11b21 provided in a portion surrounding the bearing fitting portion 11b3 and a second outer peripheral wall 11b22 provided in a portion on the opposite side with a sheave accommodating space SP1 (described later) in between. In addition, the gearbox inner wall 11b11 is provided from the outer peripheral wall 11b2 to the chain guide wall 11b5 (described later) so as to avoid the insertion hole 11a72, preventing grease from scattering inside the gearbox GB1.

[0063] The bearing fitting portion 11b3 is a portion into which the bearing B3 that axially supports the reduction gear member 60 is fitted. Note that, since the reduction gear member 60 extends from the bearing B3 toward the third frame 13, no insertion hole is provided in the bottom of the bearing fitting portion 11b3.

[0064] The bearing fitting portion 11b4 is a portion into which a bearing B5 that supports the load sheave shaft 80 is fitted. As with the above-described bearing fitting portion 11b3, since the load sheave shaft 80 extends toward the third frame 13, no insertion hole is provided in the bottom of the bearing fitting portion 11b4.

[0065] Furthermore, a half-split sheave accommodating space SP1 is provided on the G surface 11b side of the first frame 11 so as to be continuous with the bearing fitting portion 11b4. The sheave accommodating space SP1 is a space for positioning the load sheave 84, and is provided between the G surface 11b of the first frame 11 and the H surface 12a of the second frame 12.

[0066] Chain guide wall 11b5 is a wall surface for guiding load chain C2 to load sheave 84, and is configured as a half with chain guide wall 12a5 provided on the second frame 12 side. Therefore, the lower side (Z2 side) of chain guide wall 11b5, which is away from load sheave 84, is provided in a straight line, while the upper side (Z1 side) facing load sheave 84 is provided in an arc shape that follows the path of the load chain C2. In addition, grooves 11i that extend radially to the outside of the outer peripheral wall are provided in the arc-shaped portion of chain guide wall 11b5, and through-holes 11j that penetrate from G surface 11b to H surface 11a are provided in the linear portion, as shown in FIG.

[0067] The guide plate mounting portion 11b6 is a recessed portion for mounting the guide plate 90. The guide plate 90 is a plate-like member having a pair of guide holes 90a, 90b. The guide holes 90a, 90b are punched out in a generally cross shape to correspond to the vertically and horizontally oriented metal rings of the load chain C2, allowing the orientation of the load chain C2 to be aligned. The guide plate 90 is made of a material that is less likely to deform than the first frame 11 and the second frame 12, which are made of an aluminum-based metal, such as an iron-based metal.

[0068] The guide plate attachment portion 11 b 6 is provided in a half-split shape, and holds the guide plate 90 between itself and the guide plate attachment portion 12 a 6 of the second frame 12 .

[0069] The stripper mounting portion 11b7 is a portion for mounting a stripper 91, and is provided with a pair of bosses 11b71 in the configuration shown in Fig. 8. The stripper 91 is a plate-shaped member for forcibly removing the load chain C2 from the load sheave 84 when the load chain C2 bites into a chain pocket of the load sheave 84 and cannot be removed. The stripper 91 is provided with a mounting hole 91a for mounting the stripper 91 to the stripper mounting portion 11b7, and the boss 11b71 fits into the mounting hole 91a.

[0070] The arc guide accommodating portion 11b8 is a portion for attaching the chain guide 92, which has a portion formed in an arc shape, and is recessed radially outward from the chain guide wall 11b5 as shown in Figure 8. The chain guide 92 is a member for guiding the load chain C2, and has the function of preventing the load chain C2 on the side not bearing load from coming off the load sheave 84 and becoming disordered, as well as suppressing wear on the wall surface such as the chain guide wall 11b5.

[0071] Additionally, the G surface 11b is provided with a nut accommodating portion 11b9 into which a nut N2 (see FIG. 2) is fitted, the nut accommodating portion 11b9 being continuous with the shaft hole 11a9. Also, radial ribs 11b10 similar to the radial ribs 11a8 are provided from the chain guide wall 11b5 to the outer peripheral wall 11b2, as shown in FIG.

[0072] Here, the end faces of the outer peripheral wall 11b2, the chain guide wall 11b5, the radial ribs 11b10, and the gearbox inner wall 11b11 (hereinafter, these end faces will be referred to as casting surface end faces 11h) form a plane (YZ plane) perpendicular to the thickness direction (X direction) and are provided at the same distance from the plane formed by the casting surface end face 11f of the H surface 11a. Like the casting surface end face 11f, this casting surface end face 11h has the same surface roughness as when the first frame 11 was produced by aluminum die casting, and has not been subjected to machining such as cutting or grinding, which allows for a corresponding reduction in the number of processing steps.

[0073] This casting surface end surface 11h abuts against a casting surface end surface 12f located on the H surface 12a side of the second frame 12 described later when the first to third frames 11 to 13 are fastened together with the bolts BT and nuts N1.

[0074] (2-2. Second Frame 12) Next, the second frame 12 will be described. Fig. 10 is a perspective view showing the configuration of the second frame 12, as well as showing the state when viewed from the side where the hand wheel 31 is disposed. Fig. 11 is a view showing the second frame 12 as viewed from the side where the load gear 70 is disposed, and also shows some of the components attached to this second frame 12.

[0075] As shown in Figure 10, the H-surface 12a side of the second frame 12 is provided with a plate surface 12a1, an outer peripheral rib 12a2, a sheave insertion hole 12a3, a gear insertion hole 12a4, a chain guide wall 12a5, a guide plate mounting portion 12a6, a stripper mounting portion 12a7, an arc guide accommodating portion 12a8, a bolt insertion hole 12a9, and a shaft insertion hole 12a10.

[0076] The disc surface 12a1 is a wide portion in a plane (YZ plane) perpendicular to the thickness direction (X direction) of the second frame 12 and is provided to have the same height as the outer circumferential rib 12a2. In FIG. 10, the outer circumferential rib 12a2 is an outer wall surrounding the recessed portion on the H-face 12a side. The disc surface 12a1 is located opposite the second outer circumferential wall 11b22 of the first frame 11 and the end face of the chain guide wall 11b5. The outer circumferential rib 12a2 is located opposite the first outer circumferential wall 11b21 of the first frame 11, and together they define and protect the periphery of the large-diameter gear 63 as shown in FIG. 6.

[0077] The sheave insertion hole 12a3 is a hole for inserting the load sheave shaft 80. A half-split sheave accommodating space SP1 is provided so as to be continuous with the sheave insertion hole 12a3 and have a larger diameter than the sheave insertion hole 12a3. The half-split sheave accommodating space SP1, together with the half-split sheave accommodating space SP1 located on the G surface 11b side of the first frame 11, forms the sheave accommodating space SP1.

[0078] The gear insertion hole 12a4 is a hole through which the small diameter gear 64 of the reduction gear member 60 is inserted.

[0079] Chain guide wall 12a5 is the portion that faces chain guide wall 11b5 and is a wall surface that cooperates with chain guide wall 11b5 to guide load chain C2 to load sheave 84. Similar to chain guide wall 11b5, the lower side (Z2 side) of chain guide wall 12a5 that is spaced apart from load sheave 84 is provided in a straight line, but the upper side (Z1 side) that faces load sheave 84 is provided in an arc shape that follows the path of the load chain C2.

[0080] Like the guide plate mounting portion 11b6, the guide plate mounting portion 12a6 is a recessed portion for mounting the guide plate 90. Like the guide plate mounting portion 11b6, the guide plate mounting portion 12a6 is also provided in a halved shape, and holds the guide plate 90 between itself and the guide plate mounting portion 11b6 of the first frame 11.

[0081] Similarly to the stripper mounting portion 11b7, the stripper mounting portion 12a7 is a portion for mounting the stripper 91. The stripper mounting portion 12a7 is also provided with a pair of bosses 12a71, which fit into the mounting holes 91a of the stripper 91.

[0082] Similarly to the arc-shaped guide accommodating portion 11b8, the arc-shaped guide accommodating portion 12a8 is a portion for attaching the chain guide 92, a portion of which is formed in an arc shape. Similar to the stripper mounting portion 11b7, the stripper mounting portion 12a7 is also formed in a halved shape, and holds the chain guide 92 between itself and the stripper mounting portion 11b7 of the first frame 11.

[0083] The bolt insertion holes 12a9 are holes for inserting the bolts BT, and the number of bolts provided is the same as the number of bolts BT (three in FIG. 2). The shaft insertion hole 12a10 is a hole for inserting the drive shaft 40, and communicates with the insertion hole 11a72.

[0084] As shown in FIG. 9 , the bolt insertion hole 12a9 has a sloped portion 12a91 and a parallel portion 12a92. Like the sloped portion 11a61, the sloped portion 12a91 is a sloped portion designed to facilitate removal of the bolt insertion hole 12a9 from the mold. Like the parallel portion 11a62, the parallel portion 12a92 is a portion where the diameter of the hole does not change and is the smallest hole portion of the bolt insertion hole 12a9. However, the parallel portion 12a92 is located on one axial side (X1 side) of the bolt insertion hole 12a9. The clearance between the parallel portion 12a92 and the shank of the bolt BT is set smaller than the clearance between the inner and outer diameters of the bearings B1 to B6 fitted into the bearing fitting portions 11a7, 11b3, and 11b4 described above and the bearing fitting portion 12b3 (described later).

[0085] Therefore, by inserting a bolt BT into the bolt insertion hole 12a9, it is possible to position the second frame 12 relative to the first and third frames 11 and 13.

[0086] Additionally, an upper protrusion 12d that protrudes upward (toward the Z1 side) similar to the upper protrusion 11d is provided on the H surface 12a side of the second frame 12, and a connecting shaft hole 12e is also provided through the upper protrusion 12d. The connecting shaft hole 12e is a hole through which the connecting shaft 14 is inserted.

[0087] In addition, a casting surface end surface 12f similar to the casting surface end surface 11h is also provided, which abuts against the casting surface end surface 11h when the first to third frames 11 to 13 are fastened together with the bolts BT and nuts N1. Note that this casting surface end surface 12f also has the same surface roughness as when the second frame 12 was produced by aluminum die casting, and has not been subjected to machining such as cutting or grinding, which makes it possible to reduce the number of processing steps accordingly.

[0088] Next, a description will be given of the G surface 12b of the second frame 12. The G surface 12b is provided with a bottom portion 12b1, an outer peripheral wall 12b2, a bearing fitting portion 12b3, and radial ribs 12b4.

[0089] The bottom portion 12b1 corresponds to the back side of the above-mentioned board surface 12a1, and is provided in a recessed portion of the G surface 12b compared to the board surface 12a1.

[0090] The outer peripheral wall 12b2 is a wall portion that protects the components disposed therein from the outside, and is provided in an annular shape.

[0091] The bearing fitting portion 12b3 is a portion into which the bearing B2 that supports the drive shaft 40 is fitted. The bearing fitting portion 12b3 communicates with the shaft insertion hole 12a10 shown in Fig. 10 and has a larger diameter than the shaft insertion hole 12a10.

[0092] The radial ribs 12b4 protrude from the bottom portion 12b1, similar to the radial ribs 11a8 and 11b10, and improve the strength of the second frame 12.

[0093] Furthermore, a casting surface end surface 12g similar to the casting surface end surface 12f is also provided on the G surface 12b side, and when the first to third frames 11 to 13 are fixed with the bolts BT and nuts N1, this casting surface end surface 12g abuts against the casting surface end surface 13f of the third frame 13. Furthermore, this casting surface end surface 12g is a surface that has the same surface roughness as when the second frame 12 was produced by aluminum die casting, and has not been subjected to mechanical processing such as cutting or grinding, which makes it possible to reduce the number of processing steps accordingly.

[0094] (2-3. Regarding the third frame 13) Next, a description will be given of the H-face 13a of the third frame 13. As shown in Fig. 12, the H-face 13a of the third frame 13 is provided with a bottom 13a1, an outer peripheral wall 13a2, bearing fitting portions 13a3 and 13a4, bolt insertion holes 13a5, and radial ribs 13a6.

[0095] The bottom portion 13a1 is provided in a recessed portion of the H-face 13a, similar to the bottom portion 12b1. The outer peripheral wall 13a2 is a wall portion that protects the components disposed therein from the outside, similar to the outer peripheral wall 12b2, and is provided in an annular shape.

[0096] The bearing fitting portion 13a3 is a recess into which a bearing B4 that supports the reduction gear member 60 is fitted. The bearing fitting portion 13a4 is a recess into which a bearing B6 that supports the load sheave shaft 80 is fitted.

[0097] The bolt insertion holes 13a5 are holes for inserting the bolts BT, and the number of bolts provided is the same as the number of bolts BT (three in FIG. 2 ). As shown in FIG. 9 , the bolt insertion holes 13a5 are also provided with a sloped portion 13a51 and a parallel portion 13a52, similar to the bolt insertion holes 12a9 and the like. The sloped portion 13a51, like the sloped portions 11a61 and 12a91, is a sloped portion that facilitates removal of the bolt insertion hole 13a5 from the mold. Similarly to the parallel portions 11a62 and 12a92, the parallel portion 13a52 is a portion where the diameter of the hole portion does not change. The parallel portion 13a52 is provided on one axial side (X1 side) of the bolt insertion hole 13a5 and is the smallest hole portion of the bolt insertion hole 13a5. The clearance between this parallel portion 13a52 and the shaft of the bolt BT is set to be smaller than the clearance between the inner and outer diameters of the bearings B1 to B6 fitted into the above-mentioned bearing fitting portions 11a7, 11b3, 11b4, 13a3, 13a4, etc. Therefore, by inserting the bolt BT into the bolt insertion hole 13a5, it is possible to position the third frame 13 relative to the first and second frames 11 and 12.

[0098] In addition, a recess 13a53 is provided on the other axial side (X2 side) of the bolt insertion hole 13a5 to allow the head of the bolt BT to fit in and prevent the head from protruding from the third frame 13.

[0099] The radial rib 13a6 protrudes from the bottom portion 13a1, similar to the radial ribs 11a8, 11b10, and 12b4, and improves the strength of the third frame 13.

[0100] Additionally, the third frame 13 is provided with an upper protrusion 13d that protrudes upward (toward the Z1 direction) similar to the upper protrusion 11d, and the upper protrusion 13d is provided with a shaft recess 13e. The shaft recess 13e is a recess for inserting the connecting shaft 14, and is not open on the G surface 13b side.

[0101] In addition, a casting surface end surface 13f similar to the above-described casting surface end surfaces 11h, 12f, 12g is also provided, and abuts against the casting surface end surface 12g when the first to third frames 11 to 13 are fixed with the bolts BT and nuts N1. The casting surface end surface 13f is also a surface that has the same surface roughness as when the third frame 13 was produced by aluminum die casting, and has not been subjected to mechanical processing such as cutting or grinding, which makes it possible to reduce the number of processing steps accordingly.

[0102] (2-4. Regarding the chain block main body CB1 formed by assembling the first to third frames 11 to 13) An example of assembling the first to third frames 11 to 13 configured as described above using the bolts BT and nuts N1 will be described below. Note that the assembly of the chain block main body CB1 is not limited to the following description and can be modified as appropriate.

[0103] When assembling the chain block body CB1, the nut N1 is fitted into the nut accommodating portion 11a5 on the H surface 11a of the first frame 11. Then, the bearing B1 for supporting the drive shaft 40 is fitted into the bearing fitting portion 11a7, and the drive shaft 40 is inserted into the center hole and insertion hole 11a72 of the bearing B1 until the bearing B1 abuts against the flange portion 42.

[0104] Furthermore, on the G surface 11b side of the first frame 11, the bearing B3 is fitted into the bearing fitting portion 11b3, and the first bearing mounting portion 61 of the reduction gear member 60 is inserted into the central hole of the bearing B3. At this time, it is preferable that the pinion gear 46 of the drive shaft 40 and the large diameter gear 63 of the reduction gear member 60 are in mesh with each other.

[0105] Furthermore, the bearing B5 is fitted into the bearing fitting portion 11b4, and the first bearing mounting portion 82 of the load sheave shaft 80 is inserted into the central hole of the bearing B5.

[0106] Furthermore, the nuts N2 are fitted into the pair of nut accommodating portions 11b9, and the threaded portion of the claw shaft of the claw member 54 is screwed in from the H surface 11a side of the first frame 11.

[0107] The guide plate 90 is positioned on the guide plate mounting portion 11b6, and the boss 11b71 is inserted into the mounting hole 91a of the stripper 91, so that the stripper 91 is positioned on the stripper mounting portion 11b7. Furthermore, the chain guide 92 is positioned in the arc guide accommodating portion 11b8.

[0108] In this state, the H surface 12a side of the second frame 12 is aligned with the G surface 11b side of the first frame 11, and the drive shaft 40 is inserted into the shaft insertion hole 12a10. Also, the load sheave shaft 80 is inserted into the sheave insertion hole 12a3, and the small diameter gear 64 of the reduction gear member 60 is inserted into the gear insertion hole 12a4.

[0109] The guide plate 90 is positioned on the guide plate mounting portion 12a6, and the boss 12a71 is inserted into the mounting hole 91a of the stripper 91, positioning the stripper 91 on the stripper mounting portion 12a7. The chain guide 92 is then positioned in the arc-shaped guide accommodating portion 12a8. The casting surface end surface 11h of the first frame 11 and the casting surface end surface 12f of the second frame 12 are then brought into contact with each other. This holds the guide plate 90, stripper 91, and chain guide 92 between the G surface 11b of the first frame 11 and the H surface 12a of the second frame 12.

[0110] Additionally, a gearbox GB1 that houses the large diameter gear 63 of the reduction gear member 60 and a sheave accommodating space SP1 that houses the load sheave 84 of the load sheave shaft 80 are formed between the first frame 11 and the second frame 12. It is preferable to inject grease into the gearbox GB1.

[0111] Next, on the G surface 12b side of the second frame 12, the bearing B2 is fitted into the bearing fitting portion 12b3, and the second bearing attachment portion 45 of the drive shaft 40 is inserted into the center hole of the bearing B2. After that, a snap ring (reference number omitted) is attached to the end side of the drive shaft 40 to prevent the bearing B2 from moving relative to the drive shaft 40.

[0112] After this, the load gear 70 is attached to the gear attachment portion 81 of the load sheave shaft 80 .

[0113] Furthermore, a bearing B4 for supporting the reduction gear member 60 is fitted into the bearing fitting portion 13a3 of the third frame 13. Furthermore, a bearing B6 for supporting the load sheave shaft 80 is fitted into the bearing fitting portion 13a4. However, the bearing B4 may be attached to the second bearing mounting portion 62 of the reduction gear member 60, and the bearing B6 may be attached to the second bearing mounting portion 83 of the load sheave shaft 80.

[0114] In this state, the G surface 12b of the second frame 12 is aligned with the H surface 13a of the third frame 13. In this alignment, the second bearing attachment portion 62 of the reduction gear member 60 is inserted into the center hole of the bearing B4, and the second bearing attachment portion 83 of the load sheave shaft 80 is inserted into the center hole of the bearing B6. Then, the casting surface end surface 12g of the second frame 12 is brought into contact with the casting surface end surface 13f of the third frame 13. This forms the gearbox GB2, which is closed by the second frame 12 and the third frame 13. During this formation, grease is injected into GB2.

[0115] Thereafter, the first to third frames 11 to 13 are aligned, and the bolts BT are inserted into the bolt insertion holes 13a5 of the third frame 13, the bolt insertion holes 12a9 of the second frame 12, and the bolt insertion holes 11a6 of the first frame 11, in that order, until the heads of the bolts BT fit into the recesses 13a53. Additionally, the nuts N1 are fitted into the nut accommodating portions 11a5 of the third frame 11, and the bolts BT are screwed into the nuts N1. This completes the formation of the chain block body CB1.

[0116] Here, the clearances between the parallel portions 11a62, 12a92, 13a52 of the first to third frames 11 to 13 and the shafts of the bolts BT are set smaller than the clearances between the inner and outer diameters of the bearings B1 to B6 fitted into the bearing fitting portions 11a7, 11b3, 11b4, 12b3, 13a3, 13a4, etc. Therefore, by inserting the bolts BT into the bolt insertion holes 13a5, the third frame 13 can be positioned with high precision relative to the first and second frames 11 and 12.

[0117] Therefore, the positions of the bearings B1 to B6 in the YZ plane are determined based on the bolt BT and the parallel portions 11a62, 12a92, and 13a52, and the drive shaft 40, reduction gear member 60, and load sheave shaft 80 are also stably supported inside the frame assembly.

[0118] (3. Supplementary Note) The contents described in the above-described embodiment can be understood, for example, as follows: [1] That is, the chain block 10 has a chain block main body CB1 configured by sequentially stacking a first die-cast frame 11, a second die-cast frame 12, and a third die-cast frame 13 formed by die-casting a light alloy such as aluminum, and the first die-cast frame 11, the second die-cast frame 12, and the third die-cast frame 13 are provided with bearing fitting portions 11a7, 11b3, 11b4, 12b3, 13a3, and 13a4 into which bearings B1 to B6 (bearings) can be fitted.

[0119] With this configuration, the chain block body CB1 is formed by stacking the first die-cast frame 11, the second die-cast frame 12, and the third die-cast frame 13, making it possible to reduce the thickness of each of the first to third die-cast frames 11 to 13. This reduces the impact of shrinkage that occurs when molten aluminum die-cast solidifies. Furthermore, because the third die-cast frame 11, the second die-cast frame 12, and the third die-cast frame 13 are formed by aluminum die-casting, they can be processed with higher precision than castings formed in a sand mold.

[0120] Therefore, even when the first die-casting frame, the second die-casting frame, and the third die-casting frame are released from the mold, the precision of the surfaces where the frames butt against each other can be increased.

[0121] This eliminates the need for machining the surfaces where the frames butt together, thereby reducing the number of steps and processing costs.

[0122] Furthermore, as described above, it is possible to reduce the thickness of each of the first to third die-casting frames 11 to 13, which prevents deterioration in mold releasability and eliminates the need for a large draft angle for removing each of the first to third die-casting frames 11 to 13. Furthermore, compared to using steel plates as the frames, it is easier to provide bearing fitting portions 11a7, 11b3, 11b4, 12b3, 13a3, and 13a4 for fitting bearings or the like within the first to third die-casting frames 11 to 13.

[0123] [2] Furthermore, in the above embodiment, in addition to the contents described in [1] above, the first die-casting frame 11 and the third die-casting frame 13 can be configured to support a connecting shaft 14 connected to the upper hook 20 and to support a load sheave shaft 80 having a load sheave 84 around which the load chain C2 is wound.

[0124] With this configuration, the load from the upper hook 20 and the load sheave shaft 80 acts on the first die-casting frame 11 and the third die-casting frame 13. In other words, the load does not act on the second die-casting frame 12.

[0125] For example, if the connecting shaft 14 is supported by the first die-casting frame 11 and the third die-casting frame 13, and the load sheave shaft 80 is supported by the first die-casting frame 11 and the second die-casting frame 12, a shear force acts on the laminated surfaces of the second die-casting frame 12 and the third die-casting frame 13, causing uneven contact with the pinion gear 46, reduction gear member 60, load gear 70, etc. (gear members) of the first reduction gear unit G1 and the second reduction gear unit G2, which can result in problems such as a shortened lifespan of the gear members. However, by adopting the above-described configuration, it is possible to prevent the uneven contact phenomenon of the pinion gear 46, reduction gear member 60, load gear 70, etc. (gear members) from occurring, thereby making it possible to extend the lifespan of these gear members.

[0126] [3] Furthermore, in the above-described embodiment, in addition to the contents described in [1] and [2] above, or a combination thereof, a sheave accommodating space SP1 (corresponding to the first space) is provided between the first die-casting frame 11 and the second die-casting frame 12, a gear box GB2 (second space) is provided between the second die-casting frame 12 and the third die-casting frame 13, a load sheave 84 is disposed in the sheave accommodating space SP1 (first space), and a load gear 70 of a second reduction gear section G2 (reduction gear mechanism) that reduces the driving force and transmits it to the load sheave shaft 80 is disposed in the gear box GB2 (second space).

[0127] In this way, by providing the sheave accommodating space SP1 (first space) and the gearbox GB2 (second space), these spaces can be isolated from the outside of the chain block body CB1. Furthermore, by further providing the gearbox GB1, which is partitioned from the sheave accommodating space SP1 (first space), in the sheave accommodating space SP1 (first space) formed by the first die-cast frame 11 and the second die-cast frame 12, the first reduction gear unit G1 (reduction gear mechanism) and the sheave accommodating space SP1 together with the gearbox GB2 can be separated. This prevents wear powder and dust generated in the sheave accommodating space SP1, in which the load sheave 84 is located, from entering the gearbox GB1 and the gearbox GB2. Furthermore, the gearbox GB1 is provided adjacent to the sheave accommodating space SP1. Furthermore, the two-stage reduction gear mechanism is divided into a first stage first reduction gear section G1 and a second stage second reduction gear section G2, and placed in gear boxes GB1 and GB2, respectively, which makes it possible to make the second die-cast frame and third die-cast frame thin enough to be stacked and to reduce the size of the chain block 10.

[0128] [4] Furthermore, in the above-described embodiment, in addition to the contents described in any one of [1] to [3] above or a combination thereof, the first die-casting frame 11, the second die-casting frame 12, and the third die-casting frame 13 may be provided with bolt insertion holes 11a6, 12a9, 13a5, respectively, for inserting bolts BT while aligned with each other, and the gaps (clearances) between the bolt insertion holes 11a6, 12a9, 13a5 and the shanks of the bolts BT may be set smaller than the gaps (clearances) between the inner and outer diameters of the bearings B1, B3, B5, B2, B4, B6 fitted into the bearing fitting portions 11a7, 11b3, 11b4, 12b3, 13a3, 13a4.

[0129] In this way, the gaps (clearances) between the bolt insertion holes 11a6, 12a9, 13a5 and the shafts of the bolts BT are smaller than the gaps (clearances) between the inner and outer diameters of the bearings B1, B3, B5, B2, B4, B6 that fit into the bearing fitting portions 11a7, 11b3, 11b4, 12b3, 13a3, 13a4, and the bolts BT can be inserted into the bolt insertion holes 11a6, 12a9, 13a5 with the first to third die-cast frames 11 to 13 aligned, and the bolts BT and the bolt insertion holes 11a6, 12a9, 13a5 can be used as references for aligning the first to third die-cast frames 11 to 13. This eliminates the need for positioning pins or special alignment bolts for alignment, improving the ease of assembly of the chain block body CB1.

[0130] Furthermore, when the bolts BT are inserted into the bolt insertion holes 11a6, 12a9, and 13a5, they can be used as references for positioning the first to third die-cast frames 11 to 13 relative to one another during assembly.

[0131] [5] Furthermore, in the above-described embodiment, in addition to the contents of [4] above, the minimum diameter portions of the bolt insertion holes 11a6, 12a9, 13a5 can be provided with parallel portions 11a62, 12a92, 13a52 that do not have a gradient.

[0132] In this way, the presence of parallel portions 11a62, 12a92, 13a52 in the bolt insertion holes 11a6, 12a9, 13a5 makes it easier to align the first to third die-cast frames 11 to 13 with each other by inserting bolts BT into the bolt insertion holes 11a6, 12a9, 13a5 while the first to third die-cast frames 11 to 13 are aligned.

[0133] [6] In the above embodiment, in addition to any one of the above items [1] to [5] or a combination thereof, the first die-casting frame 11 is provided with a bearing fitting portion 11a7 into which a bearing B1 (bearing) is fitted that supports the drive shaft 40 through which driving force is input to the first reduction gear portion G1 (reduction gear mechanism), and a bearing fitting portion 11b4 into which a bearing B5 (bearing) is fitted that supports the load sheave shaft 80. The bearing B1 (bearing) that supports the drive shaft 40 can be configured so that the bearing B1 (bearing) is fitted from the H-face 11a side of the first die-casting frame 11, which is the side of the hand wheel 31 that transmits driving force to the drive shaft 40.

[0134] In this configuration, the load sheave shaft 80 which is the shaft of the load sheave 84 and the drive shaft 40 which is the shaft of the hand wheel 31 can be assembled to the first die-cast frame 11.

[0135] [7] Furthermore, in the above embodiment, in addition to the above-mentioned content of [6], the first die-casting frame 11 is provided with a bearing fitting portion 11b3 into which a bearing B3 (bearing) is fitted that axially supports the reduction gear member 60 that engages with the load gear 70 of the second reduction gear portion G2 (reduction gear mechanism), and the bearing fitting portion 11b3 can be configured to fit the bearing B3 (bearing) from the G surface 11b side, which is the opposite side to the hand wheel 31.

[0136] When configured in this manner, in addition to the bearing B5 (bearing) that supports the load sheave shaft 80 and the bearing B1 (bearing) that supports the drive shaft 40, the bearing B3 (bearing) that supports the reduction gear member 60 can also be positioned closely together, thereby making it possible to reduce the size of the chain block main body CB1, which is composed of the first to third die-cast frames 11 to 13.

[0137] Furthermore, the reduction gear member 60 can be disposed at the position of the drive shaft 40 in the direction of the connecting shaft 14 relative to the position of the load sheave shaft 80. In other words, with the chain block 10 suspended and the load sheave shaft 80 and the drive shaft 40, which is the shaft of the hand wheel 31, positioned horizontally, the reduction gear member 60 can be disposed diagonally above the load sheave shaft 80, making it possible to configure a manual chain block equipped with a two-stage reduction gear mechanism.

[0138] (4. Modifications) Although the embodiments of the present invention have been described above, the present invention can be modified in various other ways, which will be described below.

[0139] In the above embodiment, the chain block body CB1 is described as being made up of the first to third die-cast frames 11 to 13. However, the chain block body may be made up of four or more die-cast frames.

[0140] DESCRIPTION OF SYMBOLS 10... Chain block, 11... First die-cast frame, 11a, 12a, 13a... H-surface, 11a1... Bottom, 11a2... Outer wall, 11a3... Inner peripheral rib, 11a4... Annular recess, 11a5... Nut accommodating portion, 11a51... Step portion, 11a6, 12a9, 13a5... Bolt insertion holes (corresponding to bolt holes), 11a61, 12a91, 13a51... Sloped portion, 11a62, 12a92, 13a52... Parallel portion, 11a7, 11b3, 11b4, 12b3, 13a3, 13a4... Bearing fitting portion, 11a7 1...step portion, 11a72...insertion hole, 11a8, 11b10, 12b4, 13a6...radial rib, 11a9...shaft hole, 11b, 12b, 13b...G surface, 11b1...bottom, 11b2...outer peripheral wall, 11b21...first outer peripheral wall, 11b22...second outer peripheral wall, 11b5...chain guide wall, 11b6, 12a6...guide plate mounting portion, 11b7, 12a7...stripper mounting portion, 11b71, 12a71...boss, 11b8, 12a8...arc guide accommodating portion, 11b9...nut accommodating portion, 11c...lateral protrusion, 11d , 12d, 13d...upward protrusion, 11e, 12e...connecting shaft hole, 11f, 11h, 12f, 12g, 13f...casting surface end surface, 11g...screw hole, 11i...groove, 11j...through hole, 12...second die-cast frame, 12a1...plate surface, 12a10...shaft insertion hole, 12a2...peripheral rib, 12a3...sheave insertion hole, 12a4...gear insertion hole, 12a5...chain guide wall, 12b1...bottom, 12b2...peripheral wall, 13...third die-cast frame, 13a1...bottom, 13a2...peripheral wall, 13a53...recessed portion, 13e...shaft recess, 14...connecting shaft, 15...wheel cover, 15a...folded portion, 16...support plate, 17...protective member, 20...upper hook, 30...hand wheel assembly, 31...hand wheel, 31a...insertion hole, 31b...wheel plate portion, 33...overload prevention mechanism, 33a, 33b...clutch plate, 33c...driving member, 33c1...female thread portion, 40...drive shaft, 41...male thread portion, 42...flange portion, 44...first bearing mounting portion, 45...second bearing mounting portion, 46...pinion gear, 50...brake mechanism, 51,52...Brake plate, 53...Ratchet wheel, 54...Pawl member, 60...Reduction gear member, 61...First bearing mounting portion, 62...Second bearing mounting portion, 63...Large diameter gear, 64...Small diameter gear, 70...Load gear, 80...Load sheave shaft, 81...Gear mounting portion, 82...First bearing mounting portion, 83...Second bearing mounting portion, 84...Load sheave, 90...Guide plate, 90a, 90b...Guide hole, 91...Stripper, 91a...Mounting Hole, 92... Chain guide, B1 to B6... Bearings (bearings), BT... Bolt, C1... Hand chain, C2... Load chain, CB1... Chain block body, G1... First reduction gear section (corresponding to part of the reduction gear mechanism), G2... Second reduction gear section (corresponding to part of the reduction gear mechanism), GB1, GB2... Gear box, N1, N2... Nut, S1... Screw, SP1... Sheave accommodating space,

Claims

1. A chain block for lifting and lowering loads, comprising a chain block body constructed by stacking in order a first die-cast frame, a second die-cast frame, and a third die-cast frame, each of which is made of light alloy die-cast, and wherein the first die-cast frame, the second die-cast frame, and the third die-cast frame are provided with bearing fitting portions into which bearings can be fitted.

2. A chain block according to claim 1, wherein the first die-cast frame and the third die-cast frame support a connecting shaft that is connected to the upper hook, and also support a load sheave shaft that has a load sheave around which a load chain is wound.

3. A chain block according to claim 2, wherein a first space is provided between the first die-cast frame and the second die-cast frame, a second space is provided between the second die-cast frame and the third die-cast frame, the load sheave is disposed in the first space, and a load gear of a reduction gear mechanism that reduces the speed of the driving force and transmits it to the load sheave shaft is disposed in the second space.

4. A chain block as claimed in claim 1, wherein the first die-cast frame, the second die-cast frame and the third die-cast frame are each provided with a bolt hole for inserting a bolt while aligned with one another, and the clearance between the bolt hole and the bolt inserted into said bolt hole is set smaller than the clearance between the bearing fitting portion and the bearing inserted into said bearing fitting portion.

5. A chain block according to claim 4, wherein the smallest diameter portion of the bolt hole is provided with a parallel portion with no gradient.

6. A chain block as claimed in claim 2, wherein the first die-cast frame is provided with a bearing fitting portion into which a bearing that supports a drive shaft through which driving force is input to a reduction gear mechanism that reduces the driving force and transmits it to the load sheave shaft, and the bearing fitting portion into which the bearing that supports the load sheave shaft is fitted, and the bearing that supports the drive shaft is configured so that the bearing is fitted from the hand wheel side of the first die-cast frame that transmits driving force to the drive shaft.

7. A chain block according to claim 6, wherein the first die-cast frame is provided with a bearing fitting portion into which the bearing that supports the reduction gear member that transmits driving force to the load gear of the reduction gear mechanism is fitted, and the bearing fitting portion is configured so that the bearing is fitted from the side opposite to the hand wheel.

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