JPH0712909B2 - Mechanical winch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mechanical winch, and more particularly to a mechanical winch having a clutch and a brake device housed in a gear case.

[Prior Art] A mechanical winch for hoisting or unwinding a rope by a drum to lift or pull luggage is widely used for loading and unloading work, provided for example in a land cruiser. The drum is optionally rotated by coupling with a transmission mechanism via a clutch, and the rotation is normally stopped by a brake device for stopping a disc integrated with the drum.

FIG. 4 shows the above-mentioned conventional brake device, which includes a clutch 10
1 indicates that the brake device has been actuated at the same time as being disengaged.

In the figure, the brake device includes a disc 104 integrally provided on a drum 103 around which a rope 102 is wound, and a disc brake 105. The drum 103 is a claw that engages with a claw provided at the tip of the clutch 101. Equipped with 106. The disc brake 105 is coaxial with an L-shaped operating lever 109 whose base is pivotally supported by a bracket 108 via a shaft 107.
Pad retainer 110 pivotally attached to the pad retainer 110 and the pad retainer 1
10 and a brake pad 111 attached to the tip of the clutch lever 10.
A pin 113 that engages with 2 is provided. In addition, the operation end of the operation lever 109 turns on the disc brake 105,
It is engaged with a lock plate 114 held in the OFF state via an elastically mounted pin (not shown). Then, the pad retainer 1 pivotally attached to the base of the operation lever 109
The shaft 10 is interposed between the shaft 107 and the shaft 107 and is biased by a torsion spring (not shown).

[Problems to be Solved by the Invention] However, in such a mechanical winch, a brake device that interlocks with the clutch is provided with the outer surface of the disk integrally formed with the drum as a braking surface, and thus the side surface of the drum is Not only does it require a suitable storage space, but if these are arranged in an exposed form, special environmental measures must be taken to prevent erosion of rainwater and mud, and
Since the above-mentioned brake pad is apt to cause uneven wear due to the pivotal contact, and the braking force acting on the pad is always due to the constant biasing of the torsion spring, it is necessary to reduce the braking effect and promptly replace the pad. There is also a problem that it can be.

An object of the present invention is to technically solve the problems of simply accommodating a clutch and a brake device in a gear case to ensure environment resistance and skillfully increasing the braking force of the brake device.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a cylindrical portion extending from one end of a drum and a worm wheel connected to a drive source, which have the same spline hole formed on a common axis. A mechanical winch in which a spline hub for aligning and sealing in a gear case and selectively separating and engaging the both spline holes is arranged on a shift rod, wherein the inner peripheral surface of the gear case and the cylindrical shape of the drum are A relative annular space is formed between the outer peripheral surface of the portion and the base end of the brake shoe curvedly extending in the rewinding direction of the drum from the boss protruding from the cylindrical portion of the drum into the annular space. A first urging element that is pivotally mounted and that fits into the inner hole of the drum is mounted on the inner end of the shift rod, and the cylinder wall of the drum is operated in cooperation with the first urging element. Place the tip of the brake shoe on the gear The technical means is provided by penetrating the second biasing element that presses toward the inner peripheral surface of the roller.

A preferred form of the first and second urging elements is a compression spring that is mechanically engaged with a cam surface that moves directly, or is a compression spring that works in a radial direction with a piston that moves linearly and hydraulic oil as a medium. It is activated based on the linear movement of the shift rod that engages and disengages the clutch.

[Operation] Therefore, when the shift rod is linearly transferred from the disengaged position of the clutch to the braking position by the operation of the operation lever, the tip of the brake shoe is simultaneously actuated via the first and second biasing elements. Is urged in the centrifugal direction, the brake lining is pressed against the inner peripheral surface of the gear case, and a braking action occurs.

At this time, the rotating force acts in the loosening direction of the rope, that is, the direction in which the drum is rewound due to the suspended heavy object, but the frictional force acting on the braking surface of the brake lining is applied to the brake shoe outwardly about its pivot axis. Therefore, the brake lining is further pressed to double the braking force.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, 10 is a gear case for accommodating a pair of worms 12 and worm wheels 14, one circular hole 16 opened on the axial center of the worm wheel 14 is closed by a case cover 18, and an inner wall of the case cover 18 The tubular portion 20 extending from the fitting support the boss 22 provided on one side of the worm wheel 14, while the tubular portion 20 extends from the circular hole portion 16 extending substantially in the vicinity of the center of the gear case 10. The small-diameter circular hole portion 24 fits and supports a boss 28 having a different diameter provided on the other side of the worm wheel 14 via a plain bearing 26.

The drum 32 on which the wire rope 30 is wound has a cylindrical portion protruding further outward than an outer flange (not shown) rotatably supported by an end bracket, and is inward from the inner flange 34, that is, in the gear case 10. The cylindrical portion 36 that is inserted into the protrusion is formed in a stepped shape in which the outer diameter gradually decreases, and the large diameter portion of the base portion closes the mouth end of the circular hole portion 40 opened to the other side of the gear case 10 via the dust seal 38, and continues. The medium diameter portion 42 is fitted in the plain bearing 26 with an annular space 44 relative to the circular hole portion 40, and is supported in the form of coexisting with the worm wheel 14. The small-diameter portion that extends further is fitted into the hole of the boss 28 of the worm wheel 14 and extends to almost the central portion of the worm wheel 14.

The same spline holes 46a, 4 aligned with each other are provided in the contact area of the worm wheel 14 and the cylindrical portion 36 fitted therein.
6b is formed, and a spline hub 48 that selectively disengages the spline holes 46a, 46b is engaged to form a so-called clutch mechanism, and the spline hub 48 has a center portion of the case cover 18 as an axis. It is operated by a shift rod 50 which extends slidably in the direction and extends into the gear case 10.

A starting portion 52 as a first urging element is provided at the extending end of the shift rod 50, and the starting portion 52 having a cylindrical shape is fitted into the inner hole 54 of the cylindrical portion 36 and is provided on the outer peripheral surface. Is a conical cam surface 52
A guide surface 52b having a somewhat smaller diameter is formed so as to be continuous with a and the cam surface 52a. The spline hub 48 loosely fitted to the shift rod 50 has an outer end locked by a retaining ring 56, and a compression spring 58 is interposed between the inner end and the starting portion 52. And the shift rod 50 is a case cover
Operation lever mounted on 18 so as to be tiltable via pin 60
62 and a pin 64, which are linked to each other, and are moved back and forth based on a tilting operation of the operation lever 62. Further shift rod
The detent ball 50 is provided with a detent ball 68 which is biased by a spring 66 in order to hold the case cover 18 at the clutch engagement position, the clutch disengagement position and the braking position at the fitting portion with the case cover 18. Reference numeral 68 denotes three hemispherical recesses 70 formed on the wall of the fitting hole of the case cover 18.
It is said that it can be engaged and disengaged.

On the other hand, two bosses 72 symmetrically projecting into the annular space 44 are formed in the medium-diameter portion 42 of the drum 32, and the bosses 72 are curvedly extended in the rewinding direction of the drum 32. The base end of the brake shoe 74 is pivotally attached via a pin 76, and the brake shoe 74 is twisted around the pin 76 by a torsion spring 78 which is connected to the brake shoe 74 against the centrifugal force of rotation of the drum 32. The tip is urged so that it does not float. In addition,
Reference numeral 80 is a brake line affixed to the outer surface of the tip of the brake shoe 74.

A through hole 82 that connects the annular space 44 and the inner hole 54 is formed in the cylindrical wall of the drum 32 corresponding to the tip end portion of the brake shoe 74, and the through hole 82 serves as a second biasing element. Ball 84
Is always fitted on the guide surface 52b of the starting portion 52, and the ball 84 enters into the through hole 82 in response to the movement of the cam surface 52a, and through the spring 86. Is configured to urge the brake shoe 74 toward the peripheral surface of the circular hole portion 40.

Then, such a mechanical winch is mounted on a specially equipped vehicle such as a land cruiser, and the worm 12 is connected so as to interlock with the power take-off shaft of the vehicle.

The present embodiment is constructed as described above, and the drum 32 is allowed to rotate freely in the disengaged state of the clutch in which the spline hub 48 is disengaged from the spline hole 46a as shown in FIG. The wire rope 30 can be withdrawn at will.

From this state, if the operating lever 62 is tilted to connect the clutch and the shift rod 50 is pulled out, the detent ball
68 engages the outermost (left side in the figure) hemispherical recess 70 to hold the shift rod 50 in that position. If the spline hole 46a and the spline hub 48 are in phase at this time, the spline hub 48 moves together with the shift rod 50 and meshes with the spline hole 46a as shown by the chain line in the figure, and the rotation of the worm wheel 14 is transmitted to the drum 32. To be done.

However, when the phase of the spline hub 48 of the spline hole 46a does not match, as the shift rod 50 moves, the compression spring interposed between the spline hub 48 and the starting portion 62.
58 contracts to bias spline hub 48. After that, when the above phase matches due to the rotation of the worm wheel 14,
The urging force of the compression spring 58 causes the spline hub 48 to engage with the spline hole 46a, and the drum 32 is rotated.

On the other hand, when the operation lever 62 is tilted to disengage the clutch and the shift rod 50 is pushed in, the detent ball 68 engages with the hemispherical recess 70 located at the center, and the shift rod 50 holds its position. Then, the spline hub 48 separates from the spline hole 46 and returns to the state shown in FIG.

And, for example, because it is necessary to hold the suspension in place, the drum
When it is desired to stop the rotation of 32, the shift rod 50 is further pushed by tilting the operation lever 62 as shown by the chain line, and the detent ball 68 is located on the innermost side (right side in the figure).
The shift rod 50 is held in that position by being engaged with the hemispherical concave portion 70 located in the position. At this time, the cam surface 52a on the starting portion 52 that moves together with the shift rod 50 pushes up the ball 84 held by the guide surface 52b and advances it into the through hole 82, so that it is fitted into the through hole 82. The tip portion of the brake shoe 74 is urged outward via the generated spring 86, and the brake lining 80 is pressed against the peripheral surface of the circular hole portion 40, so that a braking force is applied to the drum 32.

At this time, due to the weight of the suspended object, a rotational force acts in the loosening direction of the wire rope 30, that is, in the direction in which the drum 32 in the free state is rewound, but the frictional force acting on the braking surface of the brake lining 80 becomes In order to generate an outward rotation moment about the pin 76, the brake lining 80 is further pressed to double the braking force. Needless to say, the release of the braking action is performed by returning the shift rod 50 to the state of FIG. 1 by the reverse operation of the operation lever 62. When the outward biasing force applied to the brake shoe 74 is erased by releasing the braking action, the tip portion of the brake shoe 74 is compressed by the relatively weak inward biasing force of the torsion spring 78 to cause the medium diameter of the drum 32. Drum that abuts the circumference of section 42 and is restarted
The levitation is suppressed against the rotational centrifugal force of 32.

In another embodiment shown in FIG. 3, the first biasing element mounted on the inner end of the shift rod 50 is closely fitted to the cylinder chamber 88 formed in the drum 32 to act on the filled hydraulic oil. First piston
90, and the second urging element is a second piston 92 that follows the linear motion of the piston 90 by using hydraulic oil as a medium, and responds radially in the through hole 82 '. Except that the braking force that acts is transmitted through a fluid, there is basically no difference from the above-described embodiment, and therefore, repeated description is omitted.

[Effects of the Invention] As described in detail above, the mechanical winch according to the present invention is configured so that both the clutch and the brake device are housed in the gear case. Therefore, in addition to simplifying the structure, rainwater and It has excellent environment resistance that completely protects the intrusion of mud, and the braking characteristics based on a unique mechanism, together with the application of the rotational moment acting on the brake shoe during braking, that is, the self-servo action. Since the braking force is doubled, the braking effect can be remarkably enhanced.

[Brief description of drawings]

1 is a sectional view taken along the line II of FIG. 2 showing an embodiment of the mechanical winch of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is the machine of the present invention. FIG. 4 is a sectional view showing another embodiment of the formula winch, and FIG. 4 is a plan view showing a conventional mechanical winch. 10 ... Gear case, 12 ... Worm 14 ... Worm wheel, 32 ... Drum 44 ... Annular space 46a, 46b ... Spline hole 48 ... Spline hub, 50 ... Shift rod 52 ... Actuator, 52a ... Cam surface 58 ... Compression spring, 62 ... Operating lever 72 ... Boss 74 ... Brake shoe, 78 ... Torsion spring 82, 82 '... Through hole, 84 ... Ball 86 ... Spring, 88 ... Cylinder chamber 90 ... First piston, 92 ... Second piston

Claims (1)

[Claims] 1. A cylindrical portion extending from one end of a drum and a worm wheel connected to a drive source are sealed in a gear case by aligning the same spline holes formed on a common shaft center with each other. A mechanical winch in which a spline hub that selectively engages and disengages holes is disposed on a shift rod, and a relative annular space is provided between the inner peripheral surface of the gear case and the outer peripheral surface of the cylindrical portion of the drum. A base end of a brake shoe curvedly extending in the rewinding direction of the drum from the boss is pivotally attached to a boss protruding from the cylindrical portion of the drum into the annular space, and the inner end of the shift rod is provided with the above. A first biasing element that fits into the inner hole of the drum is provided, and the tip of the brake shoe is directed toward the inner peripheral surface of the gear case by cooperating with the first biasing element on the cylindrical wall of the drum. Second to press
A mechanical winch that features a biasing element.