JP3211201B2 - Oil cap for electric chain block - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil cap used for a gear case of an electric chain block, and more particularly to an oil cap that does not leak oil when air is released due to an increase in the internal pressure of the gear case.

[0002]

2. Description of the Related Art When an electric chain block is operated for a long time, the temperature of gear oil rises due to frictional heat generated by the friction between gears and brakes in the gear case of the chain chain. Due to the rise, means for releasing the air in the gear case is needed.

[0003] For this reason, an oil cap is provided in the gear case of the electric chain block to release air but prevent leakage of gear oil. 2. Description of the Related Art Conventionally, as an oil cap used for a gear case of an electric chain block, for example, a structure as shown in FIG. 2 is used. Hereinafter, the related art will be described with reference to FIG.

In FIG. 2, reference numeral 21 denotes an oil cap.
A cylindrical screw part 2 fitted to the opening of the gear case is provided on the body part.
3 and a communication hole 22 which is provided at the center of the body and communicates with the gear case via a communication chamber 27. The communication chamber 27 is provided with a spring 26 and a ball 25 which is pressed by the spring 26 toward a nipple 24 provided on the gear case side of the communication chamber 27 and always closes between the gear case and the communication chamber 27.

In the above conventional apparatus, when the pressure in the gear case increases, the ball 2 is moved by the pressure in the gear case.
5 is the nipple 2 against the pressing force on the nipple 24.
4, the air in the gear case is discharged from the gap between the ball 25 and the nipple 24 to the outside through the communication chamber 27 and the communication hole 22. In this conventional apparatus, when the internal pressure in the gear case is large, there is a problem that the gear oil leaks out of the gap between the ball 25 and the nipple 24 simultaneously with the release of air.

[0006]

There is a need for the development of a simple oil cap that can release only the air in the gear case of the electric chain block and reliably prevent oil leakage. An object of the present invention is to provide a simple oil cap that can release only air in a gear case to the outside when an internal pressure in the gear case is increased in an electric chain block, thereby reliably preventing gear oil from leaking outside. And

[0007]

SUMMARY OF THE INVENTION An oil cap for an electric chain block according to the present invention has a cylindrical screw portion fitted around an outer periphery of a body in a gear case opening and a lower portion having a communication hole in the center of the body communicating with the gear case. An oil cap and an upper oil cap fitted to the upper flange of the lower oil cap. The upper oil cap is provided at the center of its body with a communication part communicating with the communication part and a closing part for closing substantially half of the communication hole of the lower oil cap. It has a groove, communicates with the outer periphery of the communication groove through a baffle provided with a slight ventilation gap, and is provided on the entire inner periphery of the upper oil cap, and has a full-peripheral groove having a vent hole that can be opened and closed by a stopper. It is characterized by the following.

According to the present invention, when the pressure in the gear case increases, the air in the gear case is discharged from the communication hole through the communication groove and the entire circumferential groove to the outside through the ventilation hole, but the gear oil in the gear case is subjected to the internal pressure. Is released from the communication hole to the communication groove due to the rise of the gear oil.However, since the communication groove and the entire circumferential groove communicate with each other through the ventilation gap of a slight gap, the gear oil is viscous and is discharged to the entire circumference groove from the ventilation gap. Instead, it stays in the communication groove and drops again into the gear case with a decrease in the pressure in the gear case. As described above, in the present invention, the oil can be reliably prevented from being discharged to the outside by a simple device without providing a sealing valve unlike the conventional device.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is an oil cap used for a gear case of an electric chain block, comprising: a cylindrical screw portion fitted around an outer periphery of a body portion with an opening of the gear case; A lower oil cap having a communication hole communicating with the gear case at the center of the body, and an upper oil cap fitted to the upper flange of the lower oil cap, and a communication hole of the lower oil cap provided at the center of the body of the upper oil cap. It has a closing part that closes almost half and a communication groove that communicates with the communication hole, and communicates with the outer circumference of the communication groove via a baffle with a slight ventilation gap, provided on the entire inner circumference of the upper oil cap, The internal peripheral groove having an opening / closing vent hole is provided, and when the internal pressure of the gear case rises, the air in the gear case communicates with the communication hole, the communication groove, the ventilation gap, and the entire peripheral groove. Then, the gear oil in the gear case is released from the communication hole due to the rise of the internal pressure into the communication groove, but the communication groove and the entire circumferential groove communicate with each other through a small air gap. Therefore, the gear oil retained in the communication groove is viscous and is not discharged to the entire circumferential groove from the ventilation gap, but remains in the communication groove, and falls again into the gear case as the pressure in the gear case decreases. As described above, the present invention has an effect of reliably preventing oil from being released to the outside by a simple device without providing a sealing valve as in the conventional device.

The second aspect of the present invention is characterized in that the ventilation hole is provided at a position communicating with the entire circumferential groove on the side of the closing portion, and has the same action as the first aspect of the invention. Further, by setting the air discharge passage longer, the air sealing effect can be further improved. Hereinafter, an embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a sectional view of an oil cap according to the present invention. In FIG. 1, reference numeral 1 denotes a lower oil cap. And a communication hole 3 communicating with the gear case at the center of the body. Reference numeral 2 denotes an upper oil cap fixed to the upper flange portion of the lower oil cap 1. The upper oil cap 2 has a closing portion 4 and a communication hole 3 at the center of the body portion, which close almost half of the communication hole 3 of the lower oil cap 1. There is provided a communication groove 6 that communicates with.

Further, a baffle 9 having a small ventilation gap 7 is provided on the outer periphery of the communication groove 6 through the upper oil cap 2.
A circumferential groove 8 is provided on the entire inner periphery of the groove.
A vent 10 is provided on the side. Reference numeral 5 denotes a plug which is inserted into the ventilation hole 10 and is made of a flexible material such as rubber. There is a seal portion 15 bulging outward from the shaft portion 14, and a ventilation gap is provided between the shaft portion 14 and the ventilation hole 10. In the closing part 4 in front of the ventilation hole 10,
A locking hole 11 for the plug 5 is provided across the entire circumferential groove 8,
Ventilation hole 1 for transportation and transfer of electric chain block
When the plug 0 is closed, by pressing the plug 5, the head 13 is fitted and locked in the locking hole 11, and the seal portion 15 closes the ventilation hole. Reference numeral 16 denotes an O-ring inserted between the lower oil cap 1 and the upper oil cap 2 as a seal and a stopper member.

The area ratio between the closing portion 4 and the communication groove 6 and the ventilation gap of the baffle are appropriately changed depending on the pressure generated in the gear case. Next, the operation of the above embodiment will be described. Since the inside of the gear case and the outside air are usually communicated without being closed, the pressure inside the gear case can be prevented from rising as in the conventional device, but even if the pressure inside the gear case rises, The air is discharged from the communication hole 3 to the outside through the communication groove 6, the ventilation gap 7, and the entire circumferential groove 8 from the ventilation hole 10, but the gear oil in the gear case also increases from the communication hole 3 to the communication groove 6 due to an increase in the pressure of the gear case. Will be released. However, in the present embodiment, since the entire circumferential groove communicates with the communication groove in the ventilation gap 7 having a slight gap, the gear oil is viscous and is not discharged from the ventilation gap to the entire circumferential groove, and It stays and drops again in the gear case as the pressure in the gear case drops and is stored.

[0014]

As described above, according to the present invention, the gear oil released from the gear case due to the pressure increase in the gear case is released from the communication hole into the communication groove, but the entire circumferential groove is slightly different from the communication groove. Because of the viscosity, the gear oil is not discharged from the ventilation gap to the entire circumferential groove due to its viscosity, but stays in the communication groove, and drops again into the gear case as the pressure in the gear case decreases. I do. As described above, in the present invention, the release of gear oil to the outside can be reliably prevented by a simple device without providing a sealing valve as in the conventional device.

Further, since the ventilation hole is provided at a position communicating with the entire circumferential groove on the closing portion side, the air discharge passage can be set long, and the air sealing effect can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an oil cap for an electric chain block according to an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional oil cap for an electric chain block.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower oil cap 2 Upper oil cap 3 Communication hole 4 Closed part 5 Plug 6 Communication groove 7 Ventilation gap 8 Full circumference groove 9 Baffle 10 Vent hole 11 Lock hole 12 Screw part 13 Head part 14 Shaft part 15 Seal part 16 O-ring

Claims (2)

(57) [Claims] 1. An oil cap used for a gear case of an electric chain block, comprising a cylindrical screw portion fitted around an outer periphery of a body and an opening of the gear case, and a lower oil having a communication hole at the center of the body communicating with the gear case. Cap and
An upper oil cap fitted to the upper flange of the lower oil cap is provided, and a communication groove communicating with the communication hole is provided at the center of the body of the upper oil cap with a closing portion closing almost half of the communication hole of the lower oil cap. The outer periphery of the communication groove is communicated through a baffle having a slight ventilation gap, and is provided on the entire inner periphery of the upper oil cap, and has an all-peripheral groove having a ventilation hole that can be opened and closed by a plug. Oil cap for chain block. 2. The oil cap for an electric chain block according to claim 1, wherein the ventilation hole is provided at a position communicating with the entire circumferential groove on the closing portion side.