JPH0460918B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a drive shaft for a chain block.

[Prior art and problems to be solved by the present invention]

The general structure of a rotation transmission mechanism between a chain wheel and a loaded wheel in a chain block is to screw a driven member 1 onto a threaded portion 2a of a drive shaft 2, and to attach the driven member 1 to the outer circumference of a boss 1a of the driven member 1. A friction plate 3, a ratchet wheel 4, and a friction plate 3' are rotatably fitted into the part, while
The hand chain wheel 5 is screwed onto the threaded portion 2a of the drive shaft 2, and the driven member 1, the drive shaft 2, and the drive shaft 2 are rotated relative to the drive shaft 2.
Rotation is transmitted between the hand chain wheel 5 and the loaded wheel wheel 6 via a reduction gear mechanism 7 installed at the leading end of the wheel (see the relevant portions in FIGS. 1 and 2).

In the above configuration, the drive shaft 2 is supported by the rotating shaft 6a of the wheel chain 6 fitted on the drive shaft 2, and the drive gear 8 fixed to the tip of the drive shaft 2 (shaft end on the opposite side to the hand chain wheel side) A reduction gear mechanism 7 includes a pair of idle gears 9, 9' that mesh with the drive gear 8, and a wheel side gear 10 that is fixed to the shaft end of the wheel rotation shaft 6a and meshes with the idle gears 9, 9'. is configured.

By the way, with the recent expansion of the range of uses for chain blocks, there is a demand for larger driving forces and smaller sizes.

However, in order to obtain as large a power factor as possible within a limited space in the above-mentioned reduction gear mechanism, the outer diameter of the drive gear 8 is made small and the distance between the drive gear 8 and the idler gears 9 and 9' is reduced. It is required to increase the tooth ratio.

Also, even if the power factor does not change, if you are trying to downsize, you will have to make the idle gear smaller.
Accordingly, the drive gear 8 is also required to be made smaller.

However, if the outer diameter of the drive gear 8 is made smaller than the outer diameter of the drive shaft 2, the drive shaft will come off to the left in FIG.

For this reason, as shown in FIG.
A circumferential groove is formed on the inner circumferential surface of a, and the snap spring 11 is fitted into this circumferential groove, and the drive shaft 2
The shaft diameter of the threaded part 2a is made smaller than that of the shaft part supported by the wheel rotating shaft 6a, and the shoulder part formed by the shaft diameter step with the threaded part 2a is received by the snap spring 11, thereby driving the wheel. It was proposed to prevent shaft 2 from coming off.

However, in the chain block having the above-mentioned configuration, the hand chain wheel 5 is moved in the hoisting direction (rightward in FIG. 1) with respect to the drive shaft by rotating the hand chain wheel, thereby pinching the friction plate. Since the shaft is rotated, which in turn rotates the chain wheel, when the hand chain wheel 5 is hoisted up, the drive shaft (including the driven member 1) is rotated according to the hoisting force.
Since it is attracted to the left in Figure 1,
The force generated in the axial direction of the drive shaft by the hand chain wheel is extremely large, and cannot be sufficiently supported by the above-mentioned proposed snap spring of the drive shaft retaining structure. In addition, it is necessary to form a shaft diameter step in the part of the drive shaft that corresponds to the inside of the chain wheel, and it is extremely difficult to install a snap spring on the inner circumference of the wheel wheel that can sufficiently withstand the axial force from the chain wheel. It turned out to be difficult. Therefore, the above-mentioned proposal can only be applied to items with small loads, and requires many work steps.

An object of the present invention is to provide a method for manufacturing a drive shaft for a chain block that enables downsizing of the chain block, can be used for large-load items, requires fewer processing and assembly steps, and has less risk of failure. That is.

[Means to solve the problem]

In the present invention, a drive shaft is rotatably inserted through the center of the shaft of a loaded wheel, and a drive gear is provided at the tip of the drive shaft, which is connected to the loaded wheel via a reduction gear mechanism. A hand chain wheel is screwed to the base end via a friction plate,
A method for manufacturing a drive shaft for a chain block in which the drive shaft is rotated through a friction plate when the hand chain wheel is hoisted up, and the chain wheel is further rotated through a drive gear and a reduction gear mechanism, the method comprising: A drive gear with an outer diameter smaller than the shaft diameter of the drive shaft is provided at the tip, and a circumferential groove is formed on the drive shaft close to the base end surface of the drive gear. A C-shaped end ring having a thickness sufficient to withstand the axial force generated on the drive shaft, and an inner diameter larger than the outer diameter of the drive gear, the inner diameter of which is larger than the drive gear when the open end is closed. A retaining ring that is an annular ring having an outer diameter smaller than the outer diameter and larger than the shaft diameter of the drive shaft is formed of hardened steel such as mild steel, and the retaining ring is fitted into the circumferential groove. This method of manufacturing a chain block drive shaft is characterized in that the opening end is closed by pressing, and the retaining ring is carburized and hardened together with the drive shaft.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 3 to 7. The rotating shaft 16a of the wagon 16 fitted onto the drive shaft 12 is connected to a pair of side plates 13, 13 forming a chain block body. A drive gear 18 that pivotally supports the drive shaft 12 by being supported between them, and is fixed to or formed as one piece on one shaft end (tip) of the drive shaft 12, and a pair of idle gears 19 meshing with the drive gear 18. , 19, and the wagon rotating shaft 16a.
A chain block configured to transmit rotation between the drive shaft 12 and the wagon 16 by means of a reduction gear mechanism 17 consisting of a gear 14 that is fixed to the shaft end of the drive shaft and meshes with the idle gears 19, 19. An alloy steel such as chrome-molybdenum steel is used as the material for the shaft 12, and a circumferential groove 12a is formed on the outer circumferential surface of the drive shaft 12 in contact with the base end surface of the drive gear. Inner diameter Di
A C-shaped retaining ring 20 with a diameter larger than the outer diameter of the drive gear 18 is fitted onto the drive shaft 12, and the retaining ring 20 positioned in the circumferential groove 12a is pressed into a press 21 or as shown in FIG. By pressing with pliers to reduce the diameter into a complete annular shape as shown in FIG. 7, this is fitted into the circumferential groove 12a, and the drive shaft 12 together with the retaining ring 20 is hardened by carburizing and heat treatment. Then, the wagon rotation shaft 16a
Receive the retaining ring 20 on the shaft end surface of the drive shaft 1.
This is designed to prevent it from slipping off to the side equipped with a hand chain wheel (No. 2).

The retaining ring 20 is deformed in diameter to form the circumferential groove 12.
a, the outer periphery of the drive shaft 12
Set the outer diameter Do so that it protrudes from the outer peripheral surface of.

In FIG. 3, reference numeral 21 denotes a holding frame attached to the side plate 13, which covers the reduction gear mechanism 17, and between this holding frame 21 and the side plate 13, the support shafts 22, 22 of the aforementioned pair of idle gears 19, 19 are connected. Each is mounted on an axis. The pair of idle gears 19, 19 have a two-stage gear shape consisting of large gears 19a, 19a that mesh with the gear 18 on the drive shaft 12 side, and small gears 19b, 19b that mesh with the gear 14 on the wagon 16 side, respectively. The rotation of the gear 18 is transmitted to the gear 14 via the idle gears 19, 19 at a reduced speed.

As the outside diameter of the retaining ring 20 increases, the cost of the above-mentioned carburizing treatment increases, so in this embodiment, the outside diameter of the stopper ring 20 is set to be slightly smaller than the outside diameter of the shaft end of the wagon rotating shaft 16a. Therefore, another washer 23 is used to prevent the gear 14 fitted onto the wheel rotation shaft 16a from coming off. This washer 23 has an inner diameter that can be fitted onto the maximum outer diameter shaft portion of the drive shaft 12, and it is possible to fit this washer 23 together with the retaining ring 20 onto the drive shaft 12 which has been carburized and hardened. can. Washiya 2
3 is positioned between the shaft end surface of the wagon rotating shaft 16a and the retaining ring 20.

The configuration on the hand chain wheel side is the same as the previous conventional example. Hand-chained cars can be either chain-driven or lever-driven.

Since both mild steel and alloy steel are effective for carburizing and hardening treatment, it is also possible to use mild steel as the material for the drive shaft 12. However, in the case of the drive shaft 12, since the load is concentrated on it, not only surface friction resistance but also sufficient internal strength is required. Therefore, alloy steel, whose internal material can be strengthened by carburizing, is better.
This is a more suitable material for the drive shaft 12.

The retaining ring 20 is fitted into the circumferential groove 12a by forming the ring so that the width w between its open ends is equal to or larger than the outer diameter of the circumferential groove 12a forming portion of the drive shaft 12.
It may be directly fitted into the circumferential groove 12a from this open end.

〔Effect of the invention〕

As described above, the present invention includes: a drive shaft rotatably inserted through the center of the shaft of a cart, and a drive gear connected to the cart via a reduction gear mechanism provided at the tip of the drive shaft; A hand chain wheel is screwed onto the base end of the drive shaft via a friction plate.
A method for manufacturing a chain block drive shaft, in which the drive shaft is rotated through a friction plate when the hand chain wheel is hoisted up, and the chain wheel is further rotated through a drive gear and a reduction gear mechanism, wherein the drive shaft is rotated through a friction plate. A drive gear is provided with an outer diameter smaller than the shaft diameter of the drive shaft, and a circumferential groove is formed on the drive shaft close to the base end surface of the drive gear. A C-shaped end ring having a thickness sufficient to withstand the axial force generated on the drive shaft and an inner diameter larger than the outer circumference of the drive gear, the inner diameter of which is equal to the outer diameter of the drive gear when the open end is closed. A retaining ring that is a smaller annular ring with an outer diameter larger than the shaft diameter of the drive shaft is formed of hardened steel such as mild steel, and the retaining ring is inserted into the circumferential groove and the retaining ring is pressed. This method of manufacturing a chain block drive shaft is characterized in that the opening end is closed by carburizing and hardening the retaining ring together with the drive shaft, and the following effects are achieved.

(1) Although the outer diameter of the drive gear can be made smaller than the outer diameter of the drive shaft, making it possible to downsize, it is difficult to form a step on the inner circumferential surface of a wagon or to create an inner circumferential groove for attaching a snap spring. There is no need to form the inner surface of the wagon, and the inner surface of the wagon can be easily processed.

(2) A circumferential groove for fixing the retaining ring is formed in contact with the proximal end surface of the drive gear, the retaining ring is fixed in this circumferential groove, and the proximal end surface of the retaining ring is slid into contact with the distal end surface of the cart. Therefore, it is easy to attach the retaining ring.

(3) After fitting and pressing a C-shaped end ring made of hardened steel such as mild steel onto the drive shaft and fixing it, the ring is carburized and hardened together with the drive shaft, so the retaining ring and the drive shaft are carburized and hardened at the same time. It can be processed and the process only needs to be done once.

(4) Since the retaining ring is made of hardened steel such as mild steel and can easily be deformed to reduce its diameter, the ring must be thick enough to withstand the large axial force generated by hoisting the hand chain wheel. Moreover, since it is carburized and hardened, it has excellent wear resistance, and the drive gear can be made smaller not only for small loads but also for large loads, and all chain block models can be made smaller. It became possible.

(5) The ring to prevent the drive shaft from hoisting up the hand-chained cart is installed in sliding contact with the front end of the hand-chained cart, and is not located inside the cart, making maintenance and inspection easy and reliable, as well as parts replacement. Repairs are also easy.

[Brief explanation of drawings]

1 and 2 are sectional views of a chain block equipped with a conventional drive shaft, respectively, FIG. 3 is a horizontal sectional view of a chain block equipped with a drive shaft of the present invention, and FIGS. 4 to 7 are circumferential sectional views. FIG. 6 is an explanatory diagram showing a procedure for attaching a retaining ring to a groove. 12... Drive shaft, 12a... Circumferential groove, 20...
Retaining ring.

Claims (1)

[Scope of Claims] 1. A drive shaft is rotatably inserted through the shaft center of the wagon, and a drive gear is provided at the tip of the drive shaft, which is connected to the wagon through a reduction gear mechanism, A hand chain wheel is screwed onto the base end of the drive shaft via a friction plate.
A method for manufacturing a drive shaft for a chain block in which the drive shaft is rotated through a friction plate when the hand chain wheel is hoisted up, and the chain wheel is further rotated through a drive gear and a reduction gear mechanism, the method comprising: A drive gear with an outer diameter smaller than the shaft diameter of the drive shaft is provided at the tip, and a circumferential groove is formed on the drive shaft in contact with the base end surface of the drive gear. A C-shaped end ring having a thickness sufficient to withstand the axial force generated on the drive shaft and an inner diameter larger than the outer diameter of the drive gear, the inner diameter of which is larger than the outer diameter of the drive gear when the open end is closed. A retaining ring that is an annular ring having an outer diameter smaller than the drive shaft diameter and larger than the shaft diameter of the drive shaft is formed of hardened steel such as mild steel, and the retaining ring is inserted into the circumferential groove. A method for manufacturing a chain block drive shaft, characterized by closing the open end by pressing, and carburizing and hardening the retaining ring together with the drive shaft.