JPS6218629Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electric chain block, and more particularly, to an electric chain block comprising a motor, a mechanical brake, and a reduction gear mechanism, and in which the motor drives a load sheave via the reduction gear mechanism. .

In general, a mechanical brake in this type of chain block consists of a hub barrel that is non-rotatably supported on an intermediate shaft of a reduction gear mechanism, a second gear of the reduction gear mechanism that is screwed onto the intermediate shaft so as to be movable in the axial direction, and a second gear of the reduction gear mechanism that is screwed onto the intermediate shaft so as to be movable in the axial direction. two friction plates rotatably supported between opposing surfaces of the second gear and the hub body, a ratchet wheel rotatably supported between these friction plates, and meshed with the ratchet wheel to prevent reverse rotation thereof. When unloading, the ratchet wheel is integrated with the second gear and hub body and rotates only in the forward rotation direction by the forward rotation of the motor, and when unloading, the While the pawl prevents the ratchet wheel from rotating in the opposite direction, the second gear is screwed back in the direction away from the ratchet wheel due to the reverse rotation of the motor, thereby creating a space between the second gear and the ratchet wheel. At the same time, the intermediate shaft is reversely rotated by the amount of reverse rotation of the second gear due to the gravity of the unloaded cargo, and the second gear is relatively moved in a direction approaching the ratchet wheel. It is configured to unload by repeating screwing back and relative movement in the axial direction with respect to the intermediate shaft.

However, in the case of an electric chain block equipped with a mechanical brake, in order to ensure that the ratchet wheel and pawl always engage reliably, the pawl is always placed between the pawl and a support member that supports the pawl. Since a pawl spring is provided that biases the ratchet wheel in the direction of the ratchet teeth, when the ratchet wheel rotates forward and the ratchet wheel disengages from the pawl, each of the ratchet teeth There is a problem in that the claws that have passed over the tips of the teeth are strongly struck against the bottoms of the teeth of the ratchet, producing a loud striking sound and causing a large noise pollution.

Furthermore, during unloading, the repetition of screwing back and moving the second gear relative to the intermediate shaft generates high-temperature frictional heat in the friction plate portion, causing damage to the inside of the gear cover that houses the mechanical brake and reduction gear mechanism. Due to the high temperature, the electrical components attached to the outside of the gear cover are heated to a high temperature, causing a problem of malfunction. Conventionally, to solve this problem, the frictional heat has been reduced by putting a large amount of high-temperature lubricating oil in the gear cover, using a friction plate with high heat resistance, or providing an oil groove on the friction surface of the friction plate. However, it was still not sufficient.

The present invention was devised in view of the above-mentioned conventional problems.The purpose is to eliminate the noise of the mechanical brake part during unloading, and to reduce the frictional heat generated by the mechanical brake part during unloading. The object of the present invention is to provide an electric chain block that can be significantly reduced in size.

Therefore, the present invention provides an electric chain block that is equipped with a motor, a mechanical brake, and a reduction gear mechanism, and the motor drives a load sheave in the forward and reverse directions through the reduction gear mechanism to wind up and lower the load sheave. An electric control mechanism for a pawl that engages with the ratchet wheel of the mechanical brake is provided, and this control mechanism is operated in conjunction with starting and stopping of the motor, and the operation of the control mechanism causes the ratchet wheel for the pawl to engage with the ratchet wheel of the mechanical brake. At the same time, a rotary member that is adjacent to the ratchet wheel via a friction plate and that rotates relative to the ratchet wheel engages with the pawl when the load sheave is rolled up by reversing the load sheave. Together,
The present invention is characterized in that an engaging protrusion is provided for forcibly releasing the engagement of the pawl with the ratchet wheel.

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

The illustrated chain block has bearing frames 3, 3 provided at the center of a pair of base plates 1, 2 facing each other at a predetermined interval, and a load is placed between these bearing frames 3, 3 via bearings 4, 4. A motor 6 and a motor brake 7 are provided on the outside of the base plate 1 on one side of the base plates 1 and 2, and a reduction gear mechanism 8 and a mechanical brake are provided on the outside of the base plate 2 on the other side. 9, a gear cover 10, an electrical component 11, and an electrical component cover 12 are provided, while bearings 13, 1 are provided between the one side bearing frame 3 and the gear cover 10.
3, an input shaft 14 passing through the load sheave 5 is rotatably supported, and this input shaft 14 and the output shaft 61 of the motor 6 are arranged in series, and the input shaft 14 and the output shaft 61 are arranged in series. A power transmission mechanism 15 is provided, with one end facing each other, and consisting of a recessed part 15a extending in the axial direction with an inclined surface between the opposing parts, and an engagement pin 15b that engages with the recessed part 5a. The rotation of the shaft 61 is transmitted from the power transmission mechanism 15 to the load sheave 5 via the input shaft 14, reduction gear mechanism 8, and mechanical brake 9.

The reduction gear mechanism 8 includes a first gear 81 fixed to the outer periphery of the other end of the input shaft 14, and an intermediate shaft 85.
a second gear 82 and a third gear 83 supported on the sheave shaft 51 of the load sheave 5;
A bearing 1 is inserted between the intermediate shaft 85 and the base plate 2 and the gear cover 10.
6 and 16, and mesh with the second gear 82 and the first gear 81, and the third gear 83 with the fourth gear 84, respectively. Further, the second gear 82 is screwed onto the intermediate shaft 85 so as to be movable in the axial direction.

The mechanical brake 9 also includes the second gear 82, a hub body 91 supported by the intermediate shaft 85 and opposed to the second gear 82, and this hub body 9.
1 and the second gear 82, a ratchet wheel 94 rotatably supported between these friction plates 92, 93, and a ratchet wheel 94 rotatably supported between the friction plates 92, 93; support,
and a pawl 95 that engages with the ratchet wheel 94.
A pawl spring 96 is provided between the pawl 95 and the gear cover 10 supporting the pawl 95, and the pawl spring 96 always urges the pawl 95 toward the ratchet tooth portion 94a of the ratchet wheel 94. A spring 96 forces the tip of the pawl 95 into the ratchet tooth portion 94.
a, and this meshing prevents the ratchet wheel 94 from rotating in the opposite direction.

This invention provides an electric control mechanism 17 for the pawl 95 that engages with the ratchet wheel 94 of the mechanical brake 9 in the chain block constructed as described above, and this control mechanism 17 is linked to the starting and stopping of the motor 6. The pawl 95 is activated by the actuation of the control mechanism 17 by starting the motor 6.
The pawl 95 is disengaged from the ratchet wheel 94, and the pawl 95 is brought into mesh with the ratchet wheel 94 by actuation of the control mechanism 17 by stopping the motor 6.
The rotating member adjacent to the hub body 91 in the drawings
is provided with an engaging protrusion 18 that engages with the pawl 95, and as the hub body 91 rotates, the engaging protrusion 18 engages with the pawl 95. It is forcibly operated in the direction away from the ratchet wheel 94 by the torque,
This is done as if the pawl 95 is forcibly disengaged from the ratchet wheel 94.

The control mechanism 17 has a rectangular cylindrical housing 17a.
A movable core 17b that is freely movably supported by the movable core 17b, and a ring-shaped electromagnetic coil 1 that receives the movable core 17b.
It consists of an electromagnet with 7c, and this electromagnet is
For example, it is attached to the outer surface of the upper wall of the gear cover 10 via a bracket 19 having an L-shaped cross section, so that the tip of the movable iron core 17b protrudes into the gear cover 10 through the through hole 10a provided in the gear cover 10, and the electromagnetic For example, connect the coil 17c to the normally open contact of an electromagnetic switch installed in the circuit to the power supply of the motor 6, and turn on the motor switch.
The operation energizes the electromagnetic coil 17c to attract the movable iron core 17b, causing the tip of the movable iron core 17b to enter the gear cover 10, and the OFF operation of the motor switch causes the electromagnetic coil 1 to attract the movable iron core 17b.
7c is cut off, and the movable iron core 17b
The force of the sprig 17d causes the spring to move backward.

Further, the claw 95 is connected to the claw shaft 97 and the bracket 9.
For example, the gear cover 10 is supported on the gear cover 10 via the claw 95.
An extension portion 95a extending outward from the pivot side edge to
and a shaft 95b protruding outward from one side of the distal end, and the extension portion 95a is connected to the movable iron core 17b.
By attracting the movable iron core 17b by the electromagnetic coil 17c, the extension portion 95
a to swing the pawl 95 in a direction away from the ratchet wheel 94, while rotatably supporting the roller 95c that engages with the engagement protrusion 18 on the shaft 95b. . Note that this roller 95c and shaft 95b are not necessarily necessary. In this case, an engaging portion that projects outward and engages with the engaging protrusion 18 may be provided on one side of the distal end side of the claw 95 .

The engaging protrusion 18 is formed in a cam shape projecting radially outward from the outer circumferential surface of the hub body 91 as shown in FIG. It makes them engage. Although one engaging protrusion 18 is provided, two or more engaging protrusions 18 may be provided.
It may protrude radially outward from one side of the.
Further, although the engaging protrusion 18 is formed separately from the hub body 91 and fixed by a fixing means such as welding, it may be formed integrally with the hub body 91.

Note that the output shaft 61 of the motor 6 is connected to the stator 62.
The input shaft 14 is supported so as to be movable in the axial direction, and the power transmission mechanism 15 applies a thrust load to the output shaft 61.

Further, in the figure, 20 is an elastic body that resists the thrust load, and 21 is a sensor that operates by elastic deformation of the elastic body 20 of a predetermined value or more. , or the circuit to the power source of the motor 6 is disconnected.

The present invention is constructed as described above, and when in use, it is suspended at a predetermined height above the ground by upper hooks (not shown) fixed to the upper parts of the base plates 1 and 2, and one end is attached to the load sheave 5. A load chain (not shown) with a lower hook (not shown) is hung, a required load is hooked to the lower hook, the motor 6 is driven, and the motor 6 is controlled in conjunction with the activation of the motor 6. While operating the movable iron core 17b of the mechanism 17, the rotation of the output shaft 61 of the motor 6 is transmitted to the load sheave 5 via the power transmission mechanism 15, input shaft 14, reduction gear mechanism 8, and mechanical brake 9. Load sheave 5 is rotated to unload and unload cargo.

When unloading by driving the motor 6 in normal rotation, the second gear 82 of the mechanical brake 9, the friction plates 92, 93, the ratchet wheel 94, and the hub body 91 are integrated, and the ratchet wheel 94 and the hub body 91 are integrated. Rotates in a direction in which the engagement with the pawl 95 is disengaged,
Since only the force of the pawl spring 96 is acting on the engaging portion between the ratchet wheel 94 and the pawl 95, the movable iron core 17b of the control mechanism 17, which operates in conjunction with the activation of the motor 6, controls the pawl. 95 operates counterclockwise in FIG. 2 to disengage the pawl 95 from the ratchet wheel 94.
Therefore, the ratchet wheel 94 can be rotated without engaging the pawl 95, and noise caused by the ratchet wheel 94 and the pawl 95 disengaging from each other can be eliminated.

Further, when unloading by driving the motor 6 in reverse, the second gear 82 is screwed back in the direction away from the friction plate 93, and at the same time, the fourth gear 84 and the third gear of the reduction gear mechanism 8 are transferred from the load sheave 5. Due to the gravity of the unloaded load acting on the intermediate shaft 85 via the intermediate shaft 83, the hub body 91 and the second gear 82
The engaging protrusion 18 provided on the hub body 91 engages with the roller 95c provided on the pawl 95 as shown in FIG.
The control mechanism 17 operates in conjunction with the activation of the motor 6 by forcibly operating the pawl 95 counterclockwise in FIG. 2 to forcibly disengage the pawl 95 from the ratchet wheel 94. movable iron core 17b
This maintains the released state of the claw.
Further, due to the gravity of the unloaded load acting on the intermediate shaft 95, the second gear 82 moves relatively toward the friction plate 93, and the ratchet wheel 94
is clamped between the second gear 82 and the hub body 91,
The second gear 82, friction plates 92, 93, ratchet wheel 94, and hub body 91 are integrated and rotate in the opposite direction. Therefore, during unloading, the frictional heat generated at the friction plates 92, 93 of the mechanical brake 9 can be significantly reduced, and malfunctions of the electrical components 11 due to heat can be reliably prevented.
Further, the amount of lubricating oil put into the gear cover 10 that houses the reduction gear mechanism 8 and the mechanical brake 9 can be reduced, and an inexpensive low-temperature lubricating oil can be used as the lubricating oil. , 93, a friction plate with low heat resistance can be used.

Furthermore, if the motor 6 is stopped during unloading or unloading, the control mechanism 1
The power supply to the electromagnetic coil 17c of No. 7 is cut off, the movable iron core 17b moves backward from inside the gear cover 10, and the pawl 95 is actuated clockwise in FIG. Since it engages with the edge wheel 94, it is possible to reliably prevent the load from descending.

In the above explanation, an electromagnet having a movable iron core 17b and an electromagnetic coil 17c is used as the control mechanism 17, but an electromagnet having an electromagnetic coil and a magnet may be used to connect the electromagnetic coil to the gear cover 10. , the magnet is provided on the claw 95, and by energizing the electromagnetic coil,
The magnet may be attracted to actuate the claw 95, or the movable iron core 17 may be actuated by the magnet.
The tip of b may be locked to the tip side of the claw 95 to operate the claw 95, or,
The pawl 95 may be actuated by rotating the pawl shaft 97 of the pawl 95 using an ultra-small motor, or may be an electric control mechanism that operates in conjunction with the starting and stopping of the motor 6. However, the mechanism is not particularly limited.

In addition, in the above explanation, the engagement protrusion 18 is connected to the hub body 9.
Although it is provided in the second gear 82, other gears may be provided in the second gear 82.

As described above, according to the present invention, when a load is unloaded, the electric control mechanism that operates in conjunction with the start and stop of the motor operates the pawl that engages with the ratchet wheel of the mechanical brake. Since the mesh can be released, it is possible to reliably eliminate the noise of the mechanical brake part during unloading, and the noise pollution caused by this noise can be eliminated.

Furthermore, during unloading, the unloading load presses the pawl against the ratchet wheel, and the ratchet is pressed against the ratchet wheel even if the pawl cannot be disengaged from the ratchet wheel, regardless of the operation of the electric control mechanism. Utilizing a rotating member that rotates relative to the wheel adjacent to the wheel, the engaging protrusion is engaged by the rotation of the rotating member, and based on the rotational torque of the rotating member,
Since the pawl can be forcibly operated to reliably disengage the ratchet wheel, the frictional heat of the mechanical brake part during unloading can be significantly reduced. Therefore, even if an electrical component is attached to the outside of the gear cover that houses the mechanical brake, malfunction of this electrical component can be reliably prevented.

Furthermore, since the pawl is forcibly operated by the rotational torque, an electromagnet with a small electric capacity can be used as the electric component of the control mechanism, and moreover, only an engaging protrusion is provided on the rotational member. Since the structure is simple, it can be provided at a low cost while still providing the above-mentioned effects.

Furthermore, since the friction plate of the mechanical brake does not work much during unloading, the frictional heat of the mechanical brake part can be reduced.
For example, the amount of lubricant to be put into the gear cover that houses the reduction gear mechanism and mechanical brake can be reduced, inexpensive low-temperature lubricant can be used as the lubricant, and friction plates with low wear resistance can be used. Therefore, the cost can be further reduced.

[Brief explanation of the drawing]

The drawings show one embodiment of the chain block of the present invention, in which Fig. 1 is a partially omitted cross-sectional plan view, Fig. 2 is an enlarged vertical cross-sectional side view, and Fig. 3 is an enlarged longitudinal cross-sectional front view with partially omitted. FIGS. 4 and 5 are explanatory diagrams showing a state in which the pawl is disengaged from the ratchet wheel. 5... Road sheave, 6... Motor, 8... Reduction gear mechanism, 9... Mechanical brake, 94...
... Ratchet wheel, 95 ... Pawl, 17 ... Control mechanism, 18 ... Engagement projection, 91 ... Hub body.

Claims (1)

[Scope of utility model registration request] An electric chain block having a motor, a mechanical brake, and a reduction gear mechanism, in which the motor drives a load sheave in forward and reverse directions via the reduction gear mechanism to perform winding and lowering, the electric chain block being characterized in that an electric control mechanism for a pawl that engages with a ratchet wheel of the mechanical brake is provided, and this control mechanism is operated in conjunction with the starting and stopping of the motor, and the operation of the control mechanism disengages the pawl from the ratchet wheel, and further comprising an engaging protrusion disposed adjacent to the ratchet wheel via a friction plate, which rotates integrally with the ratchet wheel when winding up and rotates relatively to the ratchet wheel when winding down, the engaging protrusion engaging with the pawl when winding down by the reverse rotation of the load sheave, forcibly disengaging the engagement of the pawl with the ratchet wheel.