JP4915932B2 - Chain block with built-in load-sensitive automatic transmission - Google Patents

Description

  The present invention relates to a chain block incorporating an automatic transmission, and more particularly, to a chain block incorporating a load-sensitive transmission that performs high-speed rapid feed operation when no load is applied and when the load is low.

  As will be described later, the reduction ratio of the chain block is determined based on the maximum load that the load chain can suspend and the maximum pulling force that an operator can apply to the hand chain. However, since the load chain moves at the above reduction ratio, there is a problem that work efficiency is extremely poor.

  In order to solve this problem, a chain block with a built-in transmission between the hand chain (input side) and load chain (output side) of the chain block is designed to increase the winding speed of the load chain when there is no load. Has been developed.

The chain block incorporating the above-described transmission is provided with first clutch means for transmitting rotational torque from the handwheel to the drive shaft at a one-to-one rotation ratio and to a speed increasing transmission for increasing the winding speed. 2 clutch means, a transmission plate for engaging and disengaging the first clutch means and the second clutch means, and when the handwheel is rotated when a load is applied to the load sheave, the first clutch means The transmission plate moves in the direction of engaging and releasing the second clutch means, the winding speed is switched from high speed to low speed, and the second clutch is engaged when no load is applied to increase the winding speed. It is equipped with a device. [Patent Document 1]
The chain block automatic transmission described in Patent Document 1 described above includes a first clutch means for transmitting rotational torque from the handwheel to the drive shaft at a one-to-one rotation ratio, and a first clutch means for transmitting to the speed increasing transmission. A transmission plate for switching between the two clutch means and the first and second clutch means is provided, and at the time of switching, the transmission plate is slid to mechanically switch the clutch means.

In addition, a chain block including a transmission that performs high-speed and low-speed switching by pulling a switching string provided on the chain block is also known. [Patent Document 2]
JP 2001-146391 A Japanese Patent No. 3372873

Conventionally, in the design of a chain block, the reduction ratio is determined from these ratios based on the maximum load suspended from the load chain and the maximum pulling force that an operator can apply to the hand chain.

  The above design makes it possible to lift a heavy object with a small hand pull. For example, when K = 100, a load of 25 kN (about 2.5 tf) can be lifted with a hand-drawing force of 250 N (about 25 kgf).

However, the price is that the speed of the load chain relative to the hand chain is very low.

Considering the case of K = 100 again in the above equation, in order to move the load chain by 1 m, it means that the operator must pull the hand chain by 100 m even in an empty load state. Had the problem of being forced to work very inefficiently.

  In order to solve this problem, the chain block automatic transmission described in Patent Document 1 includes two clutch mechanisms and enables high-speed winding when there is no load. Since it is a contact-type switching method that slides, it has a problem that internal resistance during switching is large and operability is poor.

  In addition, the chain block transmission described in Patent Document 2 has problems such as an operation unit such as a switching string interfering with the hoisting hand chain, or a problem that a switching operation is erroneously generated. .

  The present invention solves the above-mentioned problems, and by making the switching of the transmission incorporated in the chain block non-contact, the internal resistance is reduced, the operability is improved, and the load of the operator is reduced. To provide an automatic transmission in a chain block that can be operated safely by an overload protection function when there is no need to perform complicated gear shifting operations each time it changes, and when a load exceeding the rating is to be lifted. Objective.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem, and is a chain block having a load-sensitive automatic transmission built in between the input shaft and the output shaft of the chain block, wherein the torque transmission outside rotates at the same speed as the input shaft of the chain block. Torque provided on the inner shaft of the yoke and the outer yoke and supported by an intermediate shaft that rotates at a high speed with a pre-calculated speed increase ratio, and the outer yoke and the rotating shaft are located at different axial positions. A transmission inner yoke, an intermediate yoke that is supported between the outer yoke and the inner yoke so as to be movable in the axial direction of the output shaft, and can be opposed to the outer yoke and the inner yoke; A load-sensitive automatic transmission comprising an output disk that is supported by a shaft, coupled to an intermediate disk by a spring, and that rotates the intermediate disk relatively by load torque and moves the intermediate disk in the axial direction. The output shaft is offset to the drive shaft that drives the load sheave, both shafts are connected by the inter-shaft drive force transmission means, the intermediate yoke is made to face the inner yoke or the outer yoke by the load torque, and the output shaft is driven at high speed. Or it switches to low speed, It is characterized by the above-mentioned.

Further, the speed increasing ratio of the intermediate shaft is a value calculated by the following equation.

  Further, a reduction means is provided in the inter-axis driving force transmission means, and the speed increase of the handwheel is decelerated by the inter-axis driving force transmission means.

  Also, a load-sensitive automatic transmission is provided on the opposite side of the load sheave across the frame.

  Further, the load-sensitive automatic transmission and the chain block are arranged so that the offset between the load chain and the winding hand chain is minimized.

  Since the chain block incorporating the load-sensitive transmission of the present invention realizes switching of power transmission by a non-contact rotary thrust conversion mechanism using magnetism, mechanical contact inside the transmission is limited to only the gear and the bearing portion. Therefore, it is possible to perform a smooth switching operation, and it is not necessary for the operator to perform a complicated shifting operation every time the load state changes, and the load sensitive transmission using the magnetic clutch is overloaded. On the other hand, since it slips, when it tries to wind up the load more than a rating, it slips and has an overload protection function, Therefore Safe operation is attained.

  Moreover, since the load-sensitive transmission of the present invention can be provided with a safety device, the load can be prevented from dropping and the safety of the chain block can be further improved.

  Moreover, by setting the speed increasing ratio of the intermediate shaft to the optimum value described in claim 2, it is possible to realize the fast-forwarding operation with the empty load that makes the best use of the operator's ability.

  In addition, the transmission shaft and the drive shaft of the chain block are offset, and the transmission power between the shafts is transmitted by the inter-shaft transmission mechanism, enabling downsizing, improving the weight balance of the chain block, and hand chain By arranging the hoisting side on the load chain side, the offset between the load chain and the hand chain can be shortened, so that the shake generated during the handing can be reduced.

  In addition, by decelerating in the inter-shaft transmission mechanism, it is possible to provide a load-sensitive transmission built-in chain block that relaxes the maximum transmission torque of the transmission, and by reducing the diameter of the handwheel, the handwheel rotation is increased, As a result of decelerating the acceleration of the handwheel by the inter-shaft transmission mechanism, the rotational speed of the drive shaft of the chain block does not change, so increasing the handwheel rotation reduces the torque transmitted by the transmission, and only Since the maximum transmission torque of the transmission can be small, the transmission can be reduced in size and weight.

  Furthermore, by arranging the load-sensitive automatic transmission and the chain block so that the offset between the load chain and the winding-side hand chain is the shortest, it is possible to suppress shake during hand-drawing.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram of an automatic transmission mounted on a chain block according to the present embodiment, FIGS. 2A to 2C are schematic diagrams of a torque transmission yoke, FIG. 3 is a block diagram at high speed, and FIG. Skeleton diagram at high speed, FIG. 5 is a block diagram at low speed, FIG. 6 is a skeleton diagram at low speed, FIG. 7 is an operation explanatory diagram of an intermediate yoke, FIG. 8 is an explanatory diagram showing a thrust conversion mechanism, and FIG. FIG.

In FIG. 1, 1 is an input shaft of the handwheel, 2 is a planetary gear connected by a flange 1a of the input shaft 1 and a linear shaft 3, 2a is an internal gear meshing with the planetary gear 2, and 4 is provided on an intermediate shaft 8. The sun gear 5 that meshes with the planetary gear 2 is a low-speed input disk that is connected to the input shaft 1 by the linear shaft 3. The planetary gear 2 meshes with the sun gear 4 of the intermediate shaft 8 and rotates the intermediate shaft 8 at high speed. Reference numeral 22 denotes a torque transmission outer yoke provided around the outer peripheral surface of the low-speed input disk 5, and two rows of internal teeth 22a shown in FIG. Reference numeral 21 denotes a torque transmission inner yoke which is fixed to the intermediate shaft 8 and faces a torque transmission intermediate yoke 20 which will be described later at high speed, and rotates at a high speed. Two rows of external teeth 21a shown in FIG. It is lined up. Reference numeral 6 denotes an intermediate disk supported by the output shaft 9, which includes a flange 6a extending toward the low-speed input disk 5, and has two torque transmissions having an inner tooth 20a and an outer tooth 20b at the tip of the flange 6a. Intermediate yokes 20 are arranged in a row. (Only one yoke 20 is shown in FIG. 2 (b))
As shown in FIG. 2 (a), the torque transmission outer yoke 22 is formed of a U-shaped magnetic body that opens in the circumferential direction and rotates at the same speed as the input shaft 1, and the torque transmission outer yoke. A torque transmission inner yoke 21 made of a magnetic material having a U-shaped cross section is disposed on the inner peripheral side of the magnet 22 so as to be opposed to the outer yoke 22 and have different rotational axis positions in the axial direction. Yes. The torque transmission inner yoke 21 rotates while the input shaft 1 is accelerated. Further, between the outer yoke 22 and the inner yoke 21, a torque transmission intermediate yoke 20 that rotates at the same speed as either the outer yoke 22 or the inner yoke 21 is disposed. The intermediate yoke 20 is shown in FIG. In addition, a permanent magnet 10 is disposed between the yokes, and can be opposed to either the outer yoke 22 or the inner yoke 21. The intermediate yoke 20 is configured to face the inner yoke 21 as shown in FIG. 4 when it moves to the right in the axial direction, and to face the outer yoke 22 as shown in FIG. 6 when it moves to the left in the axial direction. Reference numeral 7 denotes an output disk supported by the output shaft 9, which is connected to the intermediate disk 6 by a magnetic rotating spring (a magnetic action that attempts to return to the neutral position when torsion occurs) and rotates relatively. It is possible. Further, as shown in FIGS. 8A and 8B, magnets having different phases and polarities are fixed on the surfaces of the intermediate disk 6 and the output disk 7, and the torque caused by the load outputs the output described above. When the torque is applied between the disc 7 and the intermediate disc 6 and the torque becomes larger than the return force of the rotary spring, the output disc 7 rotates, and the tip portion of the magnet of the output disc 7 is the magnet of the intermediate disc 6. Since the same polarity of the magnets of both magnets are opposed to each other, the intermediate disk 6 slides and moves in the axial direction due to the repulsive force. As described above, when a force greater than a predetermined torque is applied between the intermediate disk 6 and the output disk 7, the relative positions of both disks move, and when the torque decreases, the two are coupled together. Has been.

Hereinafter, the above-described thrust conversion mechanism will be described in detail. As shown in FIG. 8, the intermediate disk 6 has a permanent magnet M1, the output disk 7 has an intermediate disk 6 moving magnet MOA, and the intermediate disk 6 has magnets on both sides thereof. Magnetic spring magnets MOB for providing a return force are respectively arranged. When the load torque is initially small, the different poles of the magnet M1 disposed on the intermediate disk 6 and the magnet MOA disposed on the output disk 7 are attracted to face each other. For this reason, thrust is generated in the direction in which the intermediate disk 6 is brought closer to the output disk 7, and the intermediate disk 6 slides in the axial direction and is connected to the inner yoke 21 side. As a result, the transmission shown in FIG. 4 operates in the high speed mode. At this time, the intermediate yoke 20 to which the magnetic force of the permanent magnet M1 of the intermediate disk 6 acts is opposed to the inner yoke 21, and this position is maintained until a force that moves in a predetermined axial direction or more is applied between them. . At this time, opposite S pole of the magnet M1 of the intermediate disc is opposed to the S pole of the magnet MOB magnetic spring, the N pole of the magnet M1 of the intermediate disc 6 to the N pole of the magnet M _OB 'for the magnetic spring Therefore, in the state of being attracted with the intermediate disk moving magnet MOA as described above, the predetermined position is held by the magnetic spring action caused by the repulsive force that the magnet M1 receives from both sides. As described above, the two may be actually connected by a spring such as a tension spring and held at a predetermined position.

  Next, when the load torque increases, a torsional force is generated in the spring element that couples the intermediate disk 6 and the output disk 7, and when the force exceeds the holding force of the magnetic spring or the spring, Relative rotation. As a result, the positional relationship of the magnets changes, the magnet M1 of the intermediate disk moves to the intermediate disk moving magnet side MOA side, and the same poles of both magnets oppose each other, so that they repel each other and the intermediate disk 6 The acting thrust direction is reversed. As a result, the intermediate yoke 20 excited by the permanent magnet M1 of the intermediate disk 6 slides to a position facing the outer yoke 22 provided on the low-speed input disk 5, and is moved by the magnet 10 provided on the intermediate yoke 20. The two yokes are magnetically coupled, and the outer teeth 20b of the intermediate yoke 20 mesh with the inner yoke 22a of the outer yoke 22, so that the transmission shifts to the low speed mode and rotates corresponding to the high load.

  As described above, in the automatic transmission according to the present embodiment, when the load is low and the speed is high, the intermediate yoke 20 of the intermediate disk 6 is connected to the inner yoke 21 as shown in FIG. The speed is increased by the gear 2 and the sun gear 4 meshing with the planetary gear 2, the intermediate shaft 8 is rotated at a higher speed, and the teeth 21 a of the torque transmission inner yoke 21 supported by the intermediate shaft 8 and the torque transmission intermediate yoke 20 The internal teeth 20 a mesh with each other, the torque transmission intermediate yoke 20 rotates at high speed, and the output shaft 9 rotates at high speed via the intermediate disk 6 and the output disk 7.

  Next, at high load and low speed, as shown in FIG. 6, the intermediate yoke 20 of the intermediate disk 6 is connected to the outer yoke 22, and torque transmission provided on the low-speed input disk 5 that rotates at the same speed as the input shaft 1. The inner teeth 22a of the outer yoke 22 and the outer teeth 20b of the torque transmission intermediate yoke 20 mesh with each other, the torque transmission intermediate yoke 20 rotates at the same speed as the input shaft, and the output shaft via the intermediate disk 6 and the output disk 7 9 is rotated at low speed.

  The chain block of the present embodiment can achieve both high-speed and fast-forwarding operation with a large force and a high-efficiency chain block.

Next, a description will be given of a method for calculating the transmission speed increase ratio in which the transmission speed increase ratio at the time of low load is appropriately set and the rapid feed at the maximum speed is realized.
・ The pulling speed and force by the operator are limited to below the maximum values. ・ There is friction approximated by viscous elements such as ratchet and grease of the safety device inside the chain block. Even if the speed ratio is increased, the load chain speed does not increase monotonously, but rather starts to decrease beyond a certain speed ratio. In other words, from the above conditions, the speed increase ratio has an optimum value corresponding to the maximum load chain speed.
Operator guidance ability

Speed increase in transmission

Load chain speed of the original chain block without using a speed increasing transmission in the load chain
Actual load chain speed against
Ratio
Is defined as follows.

Viscous friction inside chain block

After the above preparations, first, the viscous resistance that appears in the hand chain attached to the transmission input shaft from equations (5), (6), and (8) increases in proportion to the square of the speed increase ratio in the transmission. That is led.

Here, if the constraints of Equations (3)-(4) are imposed on Equations (9)-(10), the state in which the operator pulls the hand chain is divided into the following two cases according to the gear ratio in the transmission. It is done. In addition, from the equations (2 ') and (7), the speed increase ratio in the load chain in each state is derived.

In region 1, the load chain speed increase ratio increases in proportion to the transmission speed increase ratio, while in region 2, it starts to decrease in inverse proportion. From equations (11)-(11 '), the relationship between the speed increase ratios of the transmission and the load chain can be arranged as shown in the following chart.

The optimum value of the transmission speed increase ratio
Is determined by the following equation at the boundary between regions 1 and 2.

By setting the speed increase ratio of the transmission to the optimum value calculated by Equation (12), it is possible to realize a fast-forward operation with an empty load that makes the best use of the operator's ability.

  FIG. 9 shows a chain block incorporating a load-sensitive transmission according to another embodiment.

  As shown in FIG. 9, the present embodiment is characterized in that the output shaft of the transmission and the shaft of the chain block are arranged at an offset. A chain block is disposed above the left side of the figure with the frame interposed therebetween, an input side device such as a hand chain is disposed below the left side, and a load sensitive transmission is disposed below the right side. Power is transmitted to the chain block shaft and the transmission shaft by an inter-shaft transmission mechanism selected from a gear train, a timing belt, and the like.

  By arranging the transmission shaft and the chain block shaft in this way, it is possible to reduce the speed in the inter-axis transmission mechanism, and by reducing the diameter of the handwheel, the rotation of the handwheel is increased and the number of handwheels is increased. As a result of decelerating the speed by the inter-shaft transmission mechanism, the rotation speed of the chain block shaft does not change, and by increasing the handwheel rotation, the torque transmitted by the transmission decreases, and the maximum transmission speed is reduced accordingly. Since the transmission torque can be relaxed, the transmission can be reduced in size and weight.

  In addition, by using an inter-shaft transmission mechanism that places the winding side of the hand chain on the load chain side, it is possible to reduce the offset between the load chain and the winding-side hand chain with a large hand-drawing force, and to suppress shaking during hand-drawing. it can.

The schematic of the automatic transmission mounted in the chain block of this invention. (A)-(c) is a schematic diagram of a torque transmission yoke. Block diagram at high speed. Skeleton diagram at high speed. Block diagram at low speed. Skeleton diagram at low speed. Operation | movement explanatory drawing of an intermediate yoke. Structure explanatory drawing of a thrust conversion mechanism. The schematic diagram of the chain block of other forms.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Planetary gear 3 Linear shaft 4 Sun gear 5 Low speed input disk 6 Intermediate disk 7 Output disk 8 Intermediate shaft 9 Output shaft 10 Permanent magnet 20 Torque transmission intermediate yoke 21 Torque transmission inner yoke 22 Torque transmission outer yoke

Claims (5)

  A chain block incorporating a load-sensitive automatic transmission between the input shaft and the output shaft of the chain block, the torque transmitting outer yoke rotating at the same speed as the input shaft of the chain block, and the input inside the outer yoke A torque transmitting inner yoke that is pivotally supported by an intermediate shaft that rotates at a high speed with a pre-calculated speed increasing ratio, and that is provided with different positions in the axial direction of the outer yoke and the rotating shaft, and the outer yoke and the inner yoke An intermediate disc that is supported in the middle of the output shaft so as to be movable in the axial direction of the output shaft, and is supported by the output shaft and an intermediate yoke that can be opposed to the outer yoke and the inner yoke, and an intermediate disc that is supported by a spring. And a load-sensitive automatic transmission comprising an output disk that rotates the intermediate disk relative to each other by load torque and moves the intermediate disk in the axial direction. The output shaft drives a load sheave. The load is characterized in that the drive shaft is offset and the two shafts are connected by inter-shaft drive force transmission means, the intermediate yoke is opposed to the inner yoke or the outer yoke by load torque, and the output shaft is switched between high speed and low speed. Chain block with built-in sensitive automatic transmission. 2. The chain block incorporating a load-sensitive automatic transmission according to claim 1, wherein the speed increasing ratio of the intermediate shaft is a value calculated by the following equation.
  3. A chain with a built-in load-sensitive automatic transmission according to claim 1 or 2, wherein a reduction means is provided in the inter-axis driving force transmission means, and the acceleration of the handwheel is decelerated by the inter-axis driving force transmission means. block.   4. A chain block incorporating a load-sensitive automatic transmission according to claim 1, wherein a load-sensitive automatic transmission is provided on the opposite side of the load sheave across the frame.   The load-sensitive automatic transmission according to claim 3 or 4, wherein the load-sensitive automatic transmission and the chain block are arranged so that the offset between the load chain and the winding hand chain is minimized. Chain block.