JP2006273490A - Over-load prevention device in winding-up machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein the number of parts and assembling man-hours are many and an accurate adjustment of urging force of a spring is difficult in a conventional over-load prevention device. <P>SOLUTION: A spring press attachment device in the over-load prevention device of the winding-up machine is provided with a rotation drive member 11 interlocked with driving of a hand wheel 9, having an engagement tooth 11a for preventing the over-load and idle-turned at over-load; a drive member 10 engaged with the engagement tooth 11a for preventing the over-load, interlocked with driving of the rotation drive member 11 and having an engagement stepped part 10f for pressing the spring; a spring member 12 for urging the rotation drive member 11; and a spring press 13 thread-engaged with the drive member 10 and pressing an end of the spring. The spring press 13 is fastened to the drive member 10 in the same direction as idle-turning direction of the rotation drive member 11 and is abutted on the engagement stepped part 10f. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an overload prevention device for a hoisting machine such as a chain block.

Conventionally, a drive shaft for driving a load sheave, a pressure receiving member fixed to the drive shaft, a drive member screwed to the drive shaft so as to be able to advance and retract, and a drive member that is rotatably fitted, A hoisting machine including a rotary drive member that transmits drive of a drive wheel to a pressing drive member is known. In such a hoisting machine, as an overload prevention device for facilitating the adjustment of the limit load of the suspended load and easily unwinding even in an overload state, a pressing drive member and What is provided with the disc spring which provides urging | biasing force with respect to a rotational drive member is known. (For example, see Patent Document 1)
Hereinafter, the overload prevention apparatus described in Patent Document 1 will be described with reference to FIGS. 14 and 15.

  FIG. 14 is a front view showing a conventional hoisting machine, and FIG. 15 is an exploded perspective view showing a main part of an overload prevention device for the hoisting machine. In FIG. 14, a drive shaft 22 is rotatably inserted in a load sheave 21. The drive shaft 22 is formed with a screw portion 22a, and the pressure receiving member 24 and the drive member 30 are screwed into the screw portion 22a from the side closer to the load sheave 21, and the pressure receiving member 24 is connected to the screw portion 22a. It is screwed to the innermost part and is fixed to the drive shaft 22. The pressure-receiving member 24 has a large-diameter disk portion 24a and a small-diameter boss portion 24b concentrically. The boss portion 24b is sandwiched between a pair of friction members 29 and 29 and an anti-reverse wheel 27 is fitted outside. Has been. The anti-reverse wheel 27 and the friction members 29 and 29 disposed on both sides of the anti-reverse wheel 27 are configured to be pressed against the disk portion 24a of the pressure receiving member 24 by the driving member 30. The anti-reverse wheel 27 is provided with a locking tooth 27a inclined on one side in the circumferential direction on the outer periphery, and the reverse rotation prevention is achieved by engaging the locking tooth 27a with a ratchet claw 28 pivotally supported on the side plate. The wheel 27 is prevented from being reversely rotated, and can rotate only in one direction with respect to the drive shaft, that is, in the winding direction. Further, in FIG. 15, locking teeth 30 c having the same shape are formed on the outer disk surface portion by the large-diameter boss portion 30 b, which is the front end surface in the axial direction of the flange portion 30 a of the drive member 30. A rotary drive member 32 is fitted on the large-diameter boss portion 30 b of the drive member 30, and the axial base end surface of the rotary drive member 32 is engageable with the locking teeth 30 c of the drive member 30. Stop teeth 32a are formed to protrude toward the proximal end in the axial direction. Each locking tooth 32 a of the rotary drive member 32 is formed in a shape that is substantially matched with a concave groove formed between the locking teeth 30 c of the drive member 30. A hand wheel 34 is fitted on the outer periphery of the rotation drive member 32. The rotation drive member 32 is positioned relative to the drive member 30 through a disk-shaped rotation limiting member 35 and a disc spring 33 which is a biasing means on a screw portion of a small-diameter boss 30d on the distal end side of the drive member 30. This is done by screwing the nut 36. A plurality of substantially short engaging convex portions 35 a are formed on the inner peripheral portion of the rotation limiting member 35 so as to protrude radially inward. The rotation restricting member 35 is restricted from moving relative to the drive member 30 in the circumferential direction, but can be moved in the axial direction. The disc spring 33 exerts an urging force so as to press the rotation drive member 32 in the axial base end direction (the drive member 30 side) via the rotation limiting member 35.

Next, the use of this conventional hoisting machine will be described. First, the nut 36 is screwed in, and the disc spring 33 as an urging means presses the rotation limiting member 35 toward the axial base end side. Since the rotation limiting member 35 is in contact with the rotation drive member 32, the rotation drive member 32 is biased toward the drive member 30. At this time, the locking teeth 30c of the drive member 30 and the locking teeth 32a of the rotation drive member 32 are engaged with each other. When a load equal to or lower than the limit load is suspended on the load chain wound around the load sheave 1, when the handwheel 34 is operated to rotate the rotation drive member 32, the rotation is caused by the locking teeth 32a, It is transmitted to the drive member 30 through 30c, and the pressure receiving member 23 can be pressed and rotated by the drive member 30 to wind up the load. On the other hand, when an overloaded load is lifted, if the rotary drive member 32 is rotated by the handwheel 34, the rotary drive member 32 resists the biasing force of the disc spring 33 together with the handwheel 34. Then, the pressing surface of the locking tooth 32 a is pushed up along the winding pressing surface of the locking tooth 30 c of the driving member 30 while being pushed back to the tip end side in the axial direction, and the locking tooth 32 a of the rotation driving member 32 is pushed. Gets over the locking teeth 30c of the driving member 30 and is engaged in the next groove between the locking teeth 30c of the driving member 30 by the biasing force of the disc spring 33. As described above, when the handwheel 34 is rotated in the winding direction in an overload state, the drive member 30 does not rotate, but only the rotation drive member 32 rotates and the drive member 30 cannot be rotated forward. Overload lifting is prevented.
Japanese Patent No. 309629 (see pages 3 to 5, see FIGS. 1 and 2)

  However, the overload prevention device in the conventional hoisting machine has a structure in which the urging means and the nut that presses the urging means are stacked on the driving member, so in order to reduce the size of the hoisting machine, As a biasing means, a small stroke biasing means such as a disc spring has to be used, so that the axial stroke of the biasing means becomes small, and the height of the overload prevention locking teeth also becomes the stroke of the disc spring. In order to give a high accuracy to the height of the locking teeth, machining or the like is required, and as shown in FIGS. 14 and 15, the number of parts is large and the cost is high. . In addition, since the height of the locking tooth for preventing overload is low, if the manufacturing tolerance is the same, the ratio of the manufacturing tolerance error to the tooth height is larger than that of the tooth having a high locking tooth height. Therefore, the variation in slip load becomes large, and the quality stability of the product is impaired. Further, it is necessary to adjust the slip load within a certain value range at the time of shipment of the hoisting machine. However, since the stroke is small, the adjustment range is small, and adjustment is difficult and skillful. Further, as shown in FIG. 14, since the handwheel is guided only slightly in contact with the flange portion of the driving member, it is easy to tilt during the hand chain operation and is influenced by the disc spring, so that the axial direction There is a problem that friction is generated on the sliding surface.

  In addition, as an overload prevention device in a hoisting machine that solves the above-mentioned problems by using an elastic member having a large stroke without increasing the hoisting device, a drive shaft for driving a load sheave in the present applicant; , A pressure receiving member externally mounted on the drive shaft, a drive member that transmits the driving force from the hand wheel to the drive shaft through the pressure receiving member, and a driving force from the hand wheel to the driving member, and a predetermined torque on the hand wheel A rotation drive member having means for releasing the engagement with the drive member when a torque greater than the value is applied, and between the back surface of the rotation drive member and the inner end face of the handwheel along the axial direction of the drive member An overload prevention device has been developed that includes a plurality of elastic members that are mounted and bias the rotational drive member.

  However, in the overload prevention device, the rotation drive member is biased by a plurality of springs arranged along the axial direction of the drive member, so that the spring pressure received by the rotation drive member becomes non-uniform. At the time of overload, the rotation driving member is easily inclined, and the inclination causes a problem that the rotation driving member interferes with the guide portion on the inner periphery of the handwheel and the movement in the axial direction cannot be smoothly performed. In addition, since the inner end surface of the handwheel is directly pressed by the spring, a frictional resistance is generated between the handwheel and the sliding surface of the washer that locks the handwheel and the drive member, and the accuracy of the washer is not necessarily high. Since it is not constant, there is a problem that the slip load between the rotary drive member and the drive member during overload is not constant.

  The present invention solves the above-described problem, and is a spring presser mounting device in an overload prevention device for a hoisting machine, which has an overload prevention engagement portion that interlocks with driving of an operating means and idles during overload. A rotation drive member, an engagement portion that engages with the overload prevention engagement portion, a spring-pressing locking step portion, a drive member that is linked to driving of the rotation drive member, and the rotation drive member A spring member to be urged and a spring presser that is screwed to the drive member and pushes the end of the spring are provided, and the spring presser is fastened to the drive member when rotated in the same direction as the idling direction of the rotary drive member. And is brought into contact with the locking step portion.

  The spring retainer has an outer diameter larger than the inner diameter of the operating means, and is slidably contacted with an annular guide portion provided on the inner peripheral end surface of the hand wheel to guide the hand wheel.

  According to the present invention, the step of mounting and setting the drive member, the rotation drive member, and the spring member on the operation means can be performed only by the step of screwing the spring presser into the drive member and contacting the spring presser engaging step. Therefore, the number of parts and assembly man-hours can be greatly reduced as compared with the conventional apparatus. In addition, since the spring retainer is screwed so as to be fastened to the drive member when it is rotated in the same direction as the idling direction of the rotation drive member, the force in the tightening direction is applied during idling of the rotation drive member due to overload. Therefore, it is possible to prevent fluctuations in the operating load due to the looseness of the spring presser. In addition, the present invention combines the function of restricting the movement of the hand wheel in the axial direction outside, the function of pressing the spring, and the function of preventing the means (nut) for pressing the spring from being loosened by only the drive member and the spring presser. As shown in FIGS. 14 and 15, it is not necessary to provide the rotation limiting member 35 provided in the overload prevention device in the conventional hoisting machine, and the processing related to this is unnecessary. Thus, the number of parts can be reduced, and the cost can be reduced. In addition, since the rotation of the operating means is guided by the guide part of the spring presser, no tilt is generated even by the tensile force in the oblique direction of the hand chain, and the operation of the hand chain and the stabilization of the operating load can be achieved.

  Further, the rotary drive member is urged with a uniform urging force by the coil member wound around the outer periphery of the drive member, so that it can move in the axial direction without causing an inclination at the time of overload. Since there is no interference with the inner peripheral surface, the operating means can be operated smoothly, and the operating means is not affected by the urging force of the spring member. Furthermore, as described above, even when the operating means is pulled diagonally, the spring member and the rotary drive member are not affected by the operation by the diagonal pulling. Can be detected stably. Furthermore, since the operating means is guided by the drive member and the spring presser, even if the operating means is tilted, the operating means does not tilt, so that stable operation is possible.

  Hereinafter, embodiments of the present invention will be described.

  A hoisting machine according to an embodiment of the present invention will be described with reference to FIGS. 1 is a front view of a hoisting machine according to an embodiment of the present invention, FIG. 2 is an enlarged view of a main part of the overload prevention device of FIG. 1, FIG. 3 is an exploded perspective view of FIG. 5 is a cross-sectional view taken along the line AA in FIG. 4, FIG. 6 is a front view of the drive member in FIG. 2, FIG. 7 is a plan view in FIG. 6, and FIG. 9 is a front view of the rotary drive member of FIG. 2, FIG. 10 is a bottom view of FIG. 9, FIG. 11 is a perspective view of FIG. 9, FIG. 12 is a front view of the spring presser of FIG. It is AA sectional drawing of 12. FIG.

  In the figure, 1 is a load sheave, 2 is a drive shaft rotatably supported by the load sheave 1, 2a is a fitting portion with the pressure receiving member 4, 3a is engaged with a gear provided at the tip of the drive shaft 2, A reduction gear 3 for reducing the rotation is engaged with a small gear (not shown) integrated with the reduction gear 3a, and a load gear for rotating the load sheave 1, 4 is a pressure receiving member, 4a is a boss portion of the pressure receiving member, and 5 is reverse rotation. The prevention wheel, 6 is a claw for controlling the reverse rotation prevention wheel 5 to rotate in one direction, 7 is a spring for urging the claw 6, 8 is a brake plate, 9 is a hand wheel as an operating means, The inner recess 9a into which the horizontally long projection 11b of the rotary drive member 11 is fitted, the inner end face 9d with which the end faces of the drive member 10 and the spring retainer 13 abut, and the guide portion 10g of the drive member 10 And sliding contact with the guide portion 13c of the spring presser 13 That includes an annular guide portion 9e. Reference numeral 10 denotes a driving member, and reference numeral 10a denotes a female screw portion of the driving member, which is screwed with the pressure receiving member 4. Reference numeral 10b denotes a flange portion of the drive member 10, which has an outer diameter larger than the inner diameter of the handwheel 9, and has an end surface in a disk shape. Reference numeral 10c denotes a boss portion into which the rotational drive member 11 and the spring 12 are inserted, and reference numeral 10d denotes engagement teeth formed on the handwheel side disk surface of the flange portion 10b. The engaging teeth 11a for use are in close contact. The engaging tooth 10d has a locking tooth portion 10j having a steep slope in a substantially right angle direction and an inclined tooth portion 10k having a gentle slope. 10e is a thread groove into which a spring retainer 13 to be described later is screwed, 10f is a positioning locking step portion with which the spring retainer abuts, and 10g is an outer peripheral surface of the flange 10b. 10h is a fan-shaped opening, and 10i is an end. A rotation restricting member 14 fixed to the end of the drive shaft 2 is inserted into the opening 10h, and the opening 10h of the drive member 10 is rotated when the drive member 10 is rotated in the loosening direction of the screw by the female screw 10a. The end portion 10i is in contact with the rotation restricting member 14 to restrict the rotation, and the drive member 10 is prevented from being loosened too much.

  In normal times, the end 10i of the opening 10h of the drive member 10 and the rotation restricting member 14 are provided with a predetermined interval in the rotation direction. Reference numeral 11 denotes a rotational drive member that fits into the boss portion 10c of the drive member 10, and the annular link portion 11e and the outer periphery of the annular link portion 11e are fitted to the fitting recess 9a of the handwheel 9 in the width direction. The drive member 10 is provided with a fitting protrusion 11b which is a horizontally long protrusion extending in the axial direction of the drive member 10, and the drive member 10 is provided on the drive member 10 side of the horizontally long protrusion 11b from the drive member 10 side end surface of the rotation drive member 11. An overload-preventing locking tooth 11 a that protrudes to the side and meshes with the engaging tooth 10 d of the driving member 10 is provided. The overload prevention locking tooth 11a has a locking tooth portion 11c having a steep slope in a substantially right angle direction and an inclined tooth portion 11d having a gentle slope.

  In this embodiment, the rotary drive member 11 can move in the axial direction of the drive member 10 along the fitting recess 9 a of the handwheel 9 against the biasing force of the spring 12 described later. As shown in FIG. 9, the axial length h of the protrusion 11 b is formed to be relatively long with respect to the thickness of the link portion 11 e, and the rotational drive member 11 is transmitted to the handwheel 9. Sufficient engagement length is secured for possible engagement. Four protrusions 11b are provided on the outer periphery of the annular link portion 11e of the rotation drive member 11, and the handwheel 9 is provided with four fitting recesses 9a. This number is not limited to four. Further, a gap for reducing friction is provided between the outer periphery of the protrusion 11 b and the fitting recess 9 a of the handwheel 9. A spring 12 urges the rotary drive member 11 toward the drive member 10. The spring 12 includes an inner spring 12 a and an outer spring 12 b, and is wound around the boss portion 10 c of the drive member 10. It is disposed in the space between the inner inner periphery 9 c of the wheel and between the rotation drive member 11 and the spring retainer 13. Reference numeral 13 denotes a spring retainer, a screw portion 13a that is screwed into the screw groove 10e of the drive member 10, a contact surface 13b that comes into contact with the locking step portion 10f of the drive member 10 when screwed to the drive member 10, and an outer periphery. It has a guide portion 13 c that has an outer diameter larger than the inner diameter of the handwheel 9 and that is in sliding contact with the annular guide portion 9 e of the handwheel 9. The spring retainer 13 is fastened to the screw groove 10a of the drive member 10a in the same direction as the idling direction of the rotary drive member 11. Reference numeral 14 denotes a rotation restricting member fixed to the end of the drive shaft 2 and fitted into the opening of the drive member 10. The hoisting machine is driven and braked by a so-called mechanical brake including a driving member 10, a pressure receiving member 4, a clutch plate 5, and a brake plate 8 connected to the handwheel 9 via a rotation driving member 11.

  As described above, the handwheel 9 is provided with a space 9f having a length substantially the same as the width of the inner periphery 9c of the handwheel 1 between the inner peripheral surface 9c and the outer periphery of the drive member 10. In this space 9f, the drive member 10 and the handwheel 9 are engaged with each other, and the rotation drive member 11 that transmits the drive of the handwheel 9 to the drive member 10 and the boss portion 10c of the drive member 10 are wound around and rotated. A spring member 12 that presses the member 11 toward the drive member 10 and a spring retainer 13 that is screwed into the screw groove 10e of the drive member 10 and holds the spring member 12 are provided.

  Further, the drive member 10 is provided with a step portion 10f for restricting the movement of the spring retainer 13 toward the rotational drive member 11 side, and the spring retainer 13 is screwed into the screw groove 10e of the drive member 10 so that the step is provided. In this state, the guide portion 13c on the outer periphery of the spring presser 13 is configured to be in sliding contact with the annular guide 9e of the handwheel 9 to guide the rotation of the handwheel 9, and The guide portion 10 g of the drive member 10 is configured to slide in contact with the annular guide 9 e on the drive member 10 side of the handwheel 9 to guide the rotation of the handwheel 9. Thus, the annular guide 9e of the handwheel 9 is slidably contacted with the guide portion 13c of the spring retainer 13 and the guide portion 10g of the drive member 10, and is supported by these guide portions. The spring member 12 wound around the drive member 10 includes a small-diameter coil spring 12a and a large-diameter coil spring 12b, and between the drive member 10 and the inner periphery 9c of the handwheel 9, between the rotary drive member 11 and the spring retainer 13. It is stretched in a cylindrical space extending straight in the axial direction. A female screw 10 a is screwed inside the driving member 10, and the female screw 10 a is screwed to a screw provided on the outer periphery of the pressure receiving member 4. A brake plate 8 is provided on the outer periphery of the pressure receiving member 4 so as to be coaxially rotatable. The brake plate 8 is a pair between the pressure receiving portion formed at one end of the pressure receiving member 4 and the driving member 10, and is attached to the pressure receiving member 4. On the other hand, it is rotatably provided. An anti-reverse wheel 5 is provided between the brake plates 8 and 8 on the outer circumference coaxial with the pressure receiving member 4.

  Reference numeral 18 denotes a frame body of a hoisting machine, which is formed by die casting using an aluminum alloy or lost wax casting.

  As shown in FIG. 1, the frame body 18 includes a drive side frame 18a and a deceleration side frame 18b, and a connection frame 18c that connects and couples both, and the frames 18a and 18b project to the drive side and the deceleration side, respectively. The drive side cover 20a and the reduction gear side cover 20b are attached in close contact with the outer peripheral edge. An opening 19a facing the drive side is formed in the drive side overhanging portion of the drive side frame 18a, and the pressure receiving member 4, the brake plate 8, the reverse rotation preventing wheel 5, the claw 6, and the spring 7 are accommodated in the opening 19a. Is done. An annular groove 19b into which the handwheel 9 is fitted is provided at a side end portion of the driving side frame 18a. The annular groove 19b has an annular groove even when the handwheel 9 is moved in the axial direction by a mechanical brake. A sufficient axial space 19c in which the handwheel is fitted in the groove 19b is provided in advance.

  With this configuration, the pressure receiving member 4, the brake plate 8, the anti-reverse wheel 5, the claw 6, and the spring 7 that are accommodated in the opening 19 a have the handwheel 9 in the annular groove 19 b provided at the side end of the drive side frame 18 a. Since it is sealed from the outside by being mounted, it is possible to prevent dust from entering from the outside, and it is possible to prevent performance degradation of the mechanical brake and the overload prevention device due to dust.

  18d and 18e are fixed to the inside of the connecting frame 18c, and can improve the wear resistance of the bearing plate for rotatably supporting the load sheave 1 and the bearing portion of the load sheave 1 by die casting. By using an aluminum alloy, the wear resistance is not lowered, and thus the weight can be reduced.

  Next, the driving force switching operation according to the present embodiment will be described. During normal operation, the rotation of the handwheel 9 is transmitted to the drive shaft 2 through the rotation drive member 11, the drive member 10, and the pressure receiving member 4, and is decelerated from the drive shaft 2 by the reduction gear 3a and the load gear 3b. Drives the load sheave 1 at a reduced speed.

  Next, the configuration and operation of the overload prevention device that operates during overload will be described. The handwheel 9 includes a coil spring 12, a rotation drive member 11, and a drive member 10. The spring 12 biases the rotation drive member 11 in the axial direction, that is, the drive member 10 side. Further, the rotation driving member 11 is connected so that the fitting convex portion 11b is fitted with the fitting concave portion 9a of the hand wheel 9, and can rotate integrally with the hand wheel 9 and can slide in the axial direction. The drive member 10 can rotate following the rotation of the rotary drive member 11 when the engagement tooth 10d of the drive member 10 meshes with the overload-preventing engagement tooth 11a of the rotary drive member 11. ing. That is, when the handwheel 9 is operated to rotate the rotation drive member 11, the drive member 10 is rotated via the overload prevention engagement teeth 11 a of the rotation drive member 11 and the engagement teeth 10 d of the drive member 10. Then, the drive member 10 presses and rotates the pressure receiving member 4, and the pressure receiving member 4 rotates to rotate the drive shaft 2, and the load sheave 1 is moved from the drive shaft 2 through the reduction gear 3a and the load gear 3b. Rotates and rolls up the load.

  When the load is lifted in an overload state and the handwheel 9 and the rotation drive member 11 are rotated in a state where a torque of a predetermined value or more is applied to the handwheel during the hoisting operation of the load, the engagement teeth of the drive member 10 are obtained. The inclined tooth portion 11d of the rotary drive member 11 meshing with 10d slides the inclined tooth portion 10k engaging surface of the engaging tooth 10d against the biasing force of the spring 12 and is pushed back in the axial direction to rotate. The engagement tooth 11a for preventing overload of the drive member 11 gets over the engagement tooth 10d of the drive member 10 and meshes with the next engagement tooth 10d of the drive member 10 by the biasing force of the spring 12, and in the overload state Since the operation of overriding the engagement tooth 10d of the drive member 10 by the overload prevention engagement tooth 11a of the rotation drive member 11 is continuously performed, the drive is not transmitted from the rotation drive member 11 to the drive member 10.

  Thus, in the overload state, when the handwheel 9 is rotated in the winding direction, the rotation drive member 11 rotates, but the overload prevention engagement teeth 11 a of the rotation drive member 11 are engaged with the drive member 10. Since the tooth 10d is slid to get over and idle, the rotation of the rotary drive member 11 is not transmitted to the drive member 10, and the winding operation at the time of overload is prevented. Since the spring retainer 13 is screwed into the screw groove 10e of the drive member 10 in the same direction as the idling direction when the rotation drive member 11 is idling, the spring retainer 13 is not loosened due to the idling operation.

  The spring retainer mounting device in the overload prevention device for a hoist according to the present invention includes a fitting convex portion 11b fitted into the fitting concave portion 9a of the handwheel 9, and an overload provided at the tip of the fitting convex portion 11b. The rotation drive member 11 having the load prevention engagement teeth 11a meshes with the overload prevention engagement teeth 11a, and interlocks with the drive of the rotation drive member 11 and has the spring presser locking step portion 10f. A spring member 12 that urges the rotary drive member 11 toward the drive member 10, and a spring retainer 13 that is screwed into a screw groove 10 e provided at the end of the drive member 10 and pushes the end of the spring member 12. The spring retainer 13 is screwed so as to be fastened to the screw groove 10e of the drive member 11 when rotated in the same direction as the idling direction of the rotary drive member 11, and the end surface of the spring retainer 13 is locked to the drive member 10. It is characterized by contacting the step Than it is. Therefore, according to the present invention, the process of mounting and setting the drive member 10, the rotary drive member 11 and the spring member 12 to the handwheel 9 can be performed only by the process of screwing the spring retainer 13 to the drive member 10. Compared to conventional devices, the number of parts and assembly man-hours can be greatly reduced. Further, when the spring presser 13 is brought into contact with the locking step portion 10f of the driving member 10, the spring setting is completed and adjustment is not necessary. Further, since the spring retainer 13 is fastened to the drive member 10 in the same direction as the idling direction of the rotation drive member 11, a force in the tightening direction acts when the rotation drive member idles due to overload. The fluctuation of the operating load due to the loosening of 13 can be prevented. Further, the present invention combines the function of restricting the movement of the hand wheel in the axial direction of the outer side, the function of pressing the spring, and the function of preventing the means (nut) for pressing the spring from being loosened by only the driving member and the spring presser. It is possible to solve the problem, and it is not necessary to provide the rotation limiting member 35 provided in FIGS. 14 and 15 in the conventional overload prevention device in the hoisting machine, and the processing related to this is unnecessary, and the number of parts is reduced. It is possible to reduce the cost. Furthermore, since the annular guide portion 9e of the handwheel 9 is rotationally guided by the guide portion 10g of the drive member 10 and the guide portion 13c of the spring retainer 13, the inclination does not occur even by the diagonal tensile force of the hand chain, It is possible to stabilize the operation of the hand chain and the operating load.

  The spring holding device in the overload prevention device of the present invention is particularly suitable for a small hoist because the overload prevention device has a small number of assembly steps and parts and is easy to adjust without increasing the size of the device. is there.

The front view of the winding machine of this invention. The principal part enlarged view of the overload prevention apparatus of FIG. FIG. 3 is an exploded perspective view of FIG. 2. The front view of the handwheel of FIG. AA sectional drawing of FIG. The front view of the drive member of FIG. The top view of FIG. AA sectional drawing of FIG. The front view of the rotation drive member of FIG. The bottom view of FIG. FIG. 10 is a perspective view of FIG. 9. The front view of the spring retainer of FIG. AA sectional drawing of FIG. The front view of the conventional mounting machine. The disassembled perspective view which shows the principal part of the overload prevention apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Load sheave 2 Drive shaft 2a Fitting part 2b Idle part 2c Engagement part 2d Screw part 3a Reduction gear 3b Road gear 4 Pressure receiving member 4a Boss part 5 Clutch board 6 Claw 7 Spring 8 Brake board 9 Hand wheel 9a Engagement recessed part 9b Insertion Groove 9c Inner inner periphery 9d Inner peripheral end surface 9e Annular guide portion 9f Space 10 Drive member 10a Female screw 10b Flange 10c Boss portion 10d Engagement tooth 10e Screw groove 10f Locking step portion 10g Guide portion 10h Opening portion 10i End portion 10j Locking tooth Part 10k Inclined tooth part 11 Rotating drive member 11a Engaging tooth 11b Fitting convex part 11c Locking tooth part 11d Inclining tooth part 11e Link part 12 Spring 12a Inner spring 12b Outer spring 12c Fitting convex part 13 Spring retainer 13a Screw part 13b Contact part 13c Guide part 14 Rotation restricting member 15 Upper hook 16 Road rod Over emissions 17 hand chain 18 frame body 18a driven-side frame 18b deceleration side frame 18c connecting off 18 d, 18e bearing plate frame 19a opening 19b annular groove 19c space 20a driving side cover 20b speed reducer side cover

Claims (2)

  A rotary drive member having an overload prevention engagement portion that idles in the event of an overload in conjunction with the drive of the operation means, an engagement portion that engages with the overload prevention engagement portion, and a spring presser locking step And a spring member that is engaged with the drive of the rotary drive member, a spring member that biases the rotary drive member, and a spring presser that engages with the drive member and pushes the spring end. In an overload prevention device for a hoisting machine, wherein the rotary drive member is screwed so as to be fastened to the drive member when rotating in the same direction as the idling direction of the rotary drive member, and is brought into contact with the locking step portion Spring clamp mounting device.   The spring presser has an outer diameter larger than the inner diameter of the operating means, and is in sliding contact with an annular guide portion provided on the inner peripheral end surface of the handwheel to guide the handwheel. Spring presser mounting device in the overload prevention device.