JPH028957Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a mechanical braking device with a ratchet structure that is incorporated into a small winch driven by a manual or an electric motor, and in particular a silent mechanical braking device that does not generate noise from the ratchet part. This relates to a braking device.

[Prior Art] A conventional manual or electric motor-driven small winch that is widely used for hoisting nets for golf courses and other sports, curtains for theater stages, etc. is a wire rope winch as shown in FIG. A reduction gear mechanism 3 is arranged at the end of the drum 2 on which the winch is wound, and a mechanical braking device 6 is provided between the drive shaft 4 on the input side of the reduction gear mechanism 3 and the operating crank handle 5. 2 is prevented from reversing, and the hanging speed is slowed down to ensure safe operation.

The mechanical braking device 6 is generally shown in FIGS. 6 and 7.
As shown in the figure, the crank handle 5 and the drive shaft 4 are connected by tightening or loosening the ratchet part that prevents the drum 2 (see Figure 5) from reversing and the ratchet wheel 7 provided on this ratchet part from both sides. It consists of a clutch part that connects or disconnects the parts.

The ratchet portion includes the ratchet 7 rotatably supported on the outer periphery of a clutch member 8, which will be described later, a pawl 9 that engages with the ratchet 7 when the ratchet 7 is reversed, and a tip of the pawl 9 that is constantly attached to the outer periphery of the ratchet 7. compression spring 10 that presses against
Consists of etc. The clutch part engages with a screw 12 cut on the outer periphery of the drive shaft 4, and connects the clutch member 8, which moves in the direction of the axis a of the drive shaft 4 by the rotation of the crank handle 5, and a pin to the drive shaft 1. 13, and two plates arranged on both sides of the ratchet wheel 7, one of which is fastened to both sides of the ratchet wheel 7 by the clutch member 8 and the other by the back plate 14. The clutch member 8 consists of friction plates 15, 15, etc.
The relative rotation angle between the screw 12 and the screw 12 is limited so that it does not become larger than the movable angle α of the indicator 16 attached to the end of the drive shaft 4.

[Problems to be solved by the invention] However, according to the above structure, the pawl 9 is always connected to the pawl wheel 7.
When the winch is hoisted, when the ratchet wheel 7 is rotated, each time each tooth 17 of the ratchet wheel 7 passes the pawl 9, the pawl 9 hits the ratchet wheel 7, producing a harsh metallic sound. Occur. Therefore, if this type of winch is used to lift theater curtains or golf nets, there are problems such as spoiling the tense atmosphere in the theater at the beginning of the curtain, and dispersing noise into the quiet living environment. Ta.

In order to avoid the above-mentioned problems, a mechanical braking device incorporating a silent irreversible roller clutch mechanism is used instead of the ratchet structure described above. This roller clutch mechanism includes, for example, a clutch case 18 formed in the shape of an automobile tire, as shown in FIG. It consists of a roller 22, a spring 23, etc. arranged in a chamber 20 surrounded by the inner side and each groove 19, and the height b in the radial direction of each chamber 20 is in the circumferential direction,
In other words, the lowering rotational direction of the drive shaft 4a (arrow c)
is gradually lowered, and when the rotation of the drive shaft 4a is interrupted, each spring 23 moves the roller 22 to the position shown by the imaginary line in the figure (arrow d), and starts reverse rotation (arrow e) due to the load. The clutch case 18 pulls each roller 22 into the narrowest part of each chamber 20, and the drawn rollers 22 bite into the inner surface of the clutch case 18 and the bottom of the groove 19 due to the wedge effect, thereby connecting the clutch case 18 and the drive shaft 4a. join together.

However, in order to operate this type of roller clutch mechanism smoothly for a long period of time, the outer surfaces of the operating parts of the roller 22, clutch case 18, and drive shaft 4a must be carburized and hardened to have high hardness. There was a problem that the cost was high.

Note that one way to obtain a roller clutch at a low cost is to use a general-purpose roller clutch commercially available from a manufacturer specializing in ball bearings. but,
In this case, the roller clutch must be held in a strong housing to compensate for its rigidity, and the housing and drive shaft must be manufactured to strict specifications regarding finished dimensions and surface hardness. However, there was a problem in that the production costs were rather high.

[Means for Solving the Problems] In view of the above-mentioned problems, the present invention was devised to provide a mechanical braking device that has a simple structure and does not generate noise during operation. A ratchet device for preventing reverse rotation, which is disposed between a driving member to be driven and a driving member that rotationally drives a drum, and has a pawl and a ratchet wheel, and a clutch that integrally connects or disconnects each driving member from each other via the ratchet wheel. A mechanical braking device comprising a winch drive member, a magnet magnetically attached to the outer peripheral surface of a cylindrical portion provided substantially concentrically with the axis of the winch drive member, and the magnet movable in a plane substantially perpendicular to the axis. and a magnet support mechanism supported by the winch drive member, the silent mechanical braking device being configured such that the pawl is engaged with or disengaged from the ratchet wheel via the magnet and the magnet support mechanism when the winch drive member rotates. It is related to.

[Operation] When the winch is being hoisted, the magnet attached to the outer periphery of the clutch member moves the pawl to the detached position outside the ratchet wheel using the rotational movement of the clutch member, so the pawl does not hit the ratchet wheel. Does not generate noise.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. Figures 1 to 4 show an embodiment in which the present invention is applied to a small manual winch (see Figure 5).The order of explanation is first to describe the structural principle of the invention, and then to explain each structural part. Give an explanation. In addition, regarding the reference numerals in the drawings, the same reference numerals are attached to the same structural parts as in the prior art described above to avoid duplication of explanation.

The principle of the present invention is that during the winding operation of the winch, the claw 32 is constantly moved by using the rotational movement of the clutch member 31.
To this end, the clutch member 31 is provided with a cylindrical portion 33 coaxially with the drive shaft 4, and a support member 35 is fixed to the rotation shaft 34 of the pawl 32 to hold the clutch member 31 in the disengaged position. A magnet 36 is attached to the clutch member 35, and the magnet 36 is magnetically attached to the outer peripheral surface of the cylindrical portion 33 of the clutch member 31, and the magnet 36 is moved to the position shown by the imaginary line by the rotational movement of the clutch member 31, and the claw 32 is moved. Hold in the disengaged position (shown in phantom).

The magnet 36 is a plate-shaped anisotropic permanent magnet made of barium ferrite bonded with rubber (for example, Plasty Form), which is sandwiched between two iron magnetic flux reinforcing plates 37, 37. The surfaces of the plates 37, 37 that are magnetically attached to the clutch member 31 are formed to have substantially the same radius of curvature so as to be in close contact with the outer peripheral surface of the clutch member cylindrical portion 33. magnet 3
A pin 38 passes through approximately the center of the pin 3.
8 is freely supported in an elongated hole 39 provided in the support member 35. The support member 35 is made of a non-magnetic material (for example, a stainless steel plate), and the magnet 36 can freely move relative to the support member 35 via a pin 38.

In addition, in case the magnet 36 and the support member 35 lose their functions due to an unexpected accident, a spring 40 that presses the distal end of the claw 32 against the ratchet wheel 7 is attached to the claw 3.
It is attached to 2.

Additionally, the device is equipped with a brake release device 42 for quickly suspending the golf net during strong winds or snowfall. This device 42 includes a rotating shaft 43 for operation, an eccentric cam 44 fixed to the rotating shaft 43, and a rotating shaft 43 that is rotated in the opposite direction to the operating direction (arrow f) so that the rotating shaft 43 cannot be easily operated except in an emergency. It consists of a spring 45 etc. that biases the eccentric cam 44 in the direction, and when activated, rotates the eccentric cam 44 to the position of the imaginary line.
The flat portion of the cam presses against the base 46 of the pawl to hold the pawl 32 in the disengaged condition.

Note that the structural parts other than those mentioned above are the same as the conventional ones (see Figures 6 and 7), so
Clarify structure and function through explanation of operation.

Next, the normal handling and operation of this device will be explained. When hoisting up a load (such as a golf net) (not shown), the crank handle 5 is rotated in the direction of arrow g (see FIG. 5). By this operation, the clutch member 31 is screwed into the screw 12,
The distance between the clutch member 31 and the back plate 14 is narrowed, the friction plates 15, 15 tighten both sides of the ratchet wheel 7, the clutch member 31 and the drive shaft 4 of the ratchet wheel 7 are integrally connected, and the drum is rotated in the winding direction. Rotate to.

On the other hand, the magnet 36 magnetically attached to the cylindrical portion 33 of the clutch member overcomes the force of the spring 40 and rotates together with the cylindrical portion 33 to the position of the imaginary line.
8. Rotate the claw 32 via the support member 35 to the release position (indicated by a phantom line). As the clutch member 31 continues to rotate further, the magnet 36 stops at the position of the imaginary line and slips on the outer peripheral surface of the cylindrical portion 33. Therefore, the pawl 32 is always in the detached position, and the pawl 32 never hits the ratchet wheel 7.

When unloading a lifted load, the clutch handle 5 is rotated by a small angle in the direction of arrow c using the function of the indicator metal 16 as a guide (see FIG. 5). By this operation, the clutch member 31 comes out slightly from the screw 12, the friction plates 15, 15 separate from the side surface of the ratchet wheel 7, and the drive shaft 4, ratchet wheel 7, and clutch member 3
1 is disconnected from each other, and the drive shaft 4 rotates in the unwinding direction due to the load. This rotational movement of the drive shaft 4 screws the screw 12 into the clutch member 31, tightens the friction plates 15, 15 to the ratchet wheel 7, and connects the drive shaft 4, ratchet wheel 7, and clutch member 31 together.

During this time, the magnet 36 magnetically attaches to the clutch member 31 and moves to the solid line position, and the pawl 36 is attached to the clutch member 31 via the support member 35.
2 is rotated to the engagement position shown by the solid line, and unloading of the load is automatically stopped when the drive shaft 4, ratchet wheel 7, and clutch member 31 are integrally connected.
Here, the crank handle 5 is again rotated in the direction of arrow c, and the golf net is thus suspended little by little.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[Effects of the invention] As described above, the present invention exhibits the following excellent effects.

(i) A magnet is attached to the clutch member, and the rotation of the clutch member is used to drive the pawl into engagement with and disengagement from the ratchet wheel. No hitting cars,
Does not generate noise.

(ii) Unlike when using a roller clutch, there is no need for high-precision, high-hardness parts, and it is sufficient to simply add a pawl drive mechanism using a magnet, so the structure is simple; Production costs are low.

[Brief explanation of the drawing]

1 to 4 show embodiments of the present invention,
Fig. 1 is an explanatory diagram showing the arrangement of the clutch member cylindrical part, magnet, pawl, and ratchet wheel, which are the main parts of the present invention, and is a view taken from the - direction in Fig. 2, and Fig. 2 is a plan view of the device. The left half is a cutaway view, Figure 3 is a view from the - direction in Figure 2, Figure 4 is a view from the - direction in Figure 3, and Figure 5 is a general small manual winch. Conceptual diagram, Figures 6 and 7
The figures are explanatory diagrams of a conventional mechanical braking device incorporating a ratchet structure, in which Fig. 6 is a partially cutaway plan view, Fig. 7 is a view taken from the - direction in Fig. 6;
FIG. 8 is an explanatory diagram of the irreversible roller clutch mechanism. In the figure, 7 is a ratchet wheel, 15 is a friction plate, 31 is a clutch member, 32 is a pawl, 33 is a cylindrical portion, 35 is a support member, 36 is a magnet, and 38 is a pin.

Claims (1)

[Scope of utility model registration request] A ratchet device for preventing reverse rotation, which is disposed between a drive member that rotationally drives the winch and a drive member that rotatably drives the drum, and has a pawl and a ratchet wheel, and the drive members are integrally connected to each other through the ratchet wheel. or a mechanical braking device equipped with a clutch device that separates the winch drive member, the winch drive member includes a magnet magnetically attached to the outer peripheral surface of a cylindrical portion provided substantially concentrically with the axis of the winch drive member, and the magnet is attached in a plane substantially perpendicular to the axis. and a magnet support mechanism that movably supports the winch drive member, and is configured such that the pawl is engaged with or disengaged from the ratchet wheel via the magnet and the magnet support mechanism when the winch drive member rotates. type braking device.