JPH06206696A - Overload preventive device for hoisting-towing machine - Google Patents

Abstract

PURPOSE:To prevent an overload effectively by controlling a surface condition of an opposite surface where friction plates of a driving side member and driven side members come into contact with each other, holding a preset value of transmission torque in a proper value, and causing a slip reliably by the overload exceeding the preset value. CONSTITUTION:Friction control layers 100 which are composed of a metal plating layer of nickel-phosphorus, nickel-chrome and chrome and are formed by carrying out heat treatment on this metal plating layer, are formed on an opposite surface where friction plates 11 and 12 of a driving side member 10 and driven side members 8 and 16 come into contact with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overload preventing device for a hoisting / traction machine, and more specifically, a load which is interposed between a driving side member and a driven side member and which acts on a load sheave of the hoisting / traction machine. But,
The present invention relates to an overload prevention device that slips when a set transmission torque is exceeded to cut off the power transmission from the driving side member to the driven side member, thereby making it impossible to hoist or pull luggage over the rated load.

[0002]

2. Description of the Related Art Conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 51-100950, a hoisting / traction machine is provided with an overload preventing device in a power transmission system from a driving member to a load sheave. ing.

The overload prevention device disclosed in the above publication is provided on an intermediate transmission shaft of a gear reduction mechanism provided between a drive shaft driven by a motor and a load sheave. A non-rotatably fitted receiving member having a sleeve and a flange on the sleeve of the receiving member,
A driven gear that meshes with the drive gear of the drive shaft is inserted, and annular friction plates are inserted on both sides of the driven gear, and a pressing member and a disc spring are inserted on the opposite flange side of the driven gear. In addition, an adjustment nut for overload setting is screwed onto the sleeve.

In this structure, the driven gear serves as a driving side member, and the receiving member and the pressing member coupled to the intermediate transmission shaft serve as a driven side member. By tightening the adjusting nut, The transmission torque from the driving side member to the driven side member is set, and when the load acting on the load sheave exceeds the set transmission torque, slipping and damage due to overload can be prevented.

[0005]

However, in recent years, the hoisting / traction machine has been required to be downsized, and the overload prevention device is equipped to prevent the overload from increasing in size. The prevention device itself is also miniaturized, and as a result, the diameter of the friction plate is reduced. Therefore, the contact area of each of the facing surfaces of the driving side member and the driven side member that face the friction plate and contact the friction plate becomes small, and in order to obtain a predetermined transmission torque, tighten the adjustment nut. The friction plate is strengthened to increase the surface pressure, and the hardness of the friction plate is also increased accordingly.

However, when a friction plate made of a hard material and having a small diameter as described above is used and the upper surface pressure is increased,
It was found that even if the transmission torque during assembly was set to a predetermined value, there were many variations in slip load with use.

As a result of investigating the cause of this point, in the structure of the above-mentioned overload preventing device, the driven gear serving as the driving side member and the facing surface of the receiving member serving as the driven side member are in contact with each other. It is formed from the surface of the material, and its friction coefficient is not controlled at all.If the friction plate is made of a hard material, it is attacked by this friction plate and the surface depends on how it is attacked. It has been clarified that the cause is that the change in the state and the further strict variation when external conditions such as rusting are added.

An object of the present invention is to control the surface condition of the facing surfaces of the friction plates of the driving side member and the driven side member which are in contact with each other, and to maintain the set value of the transmission torque at an appropriate value. The point is that slip is surely caused by an overload that exceeds the set value, and overload can be effectively prevented.

[0009]

In order to achieve the above object, the present invention comprises a driving side member 10 and driven side members 8 and 16, and the driving side member 10 and the driven side members 8 and 16 face each other. Elastic members 13 for interposing the friction plates 11 and 12 between the surfaces and for pressing the friction plates 11 and 12 against the facing surfaces.
In the overload prevention device for a hoisting / traction machine, which is provided with an overload setting adjusting member 14, nickel-phosphorus, nickel-chromium or chrome is provided on each of the facing surfaces with which the friction plates 11 and 12 are in contact. The friction control layer 100 is formed by heat treating the plated layer.

Further, the heat treatment temperature of the plating layer is set to the austenite transformation point temperature of the driving side member 10 and the driven side members 8 and 16 on which the plating layer is provided, and the plating layer is the driving side and driven side members 10 and 8. , 16 is preferably provided on the surface of the material to spread the friction control layer 100.

[0011]

Since the friction control layer 100 is provided on the drive side member 10 and the driven side members 8 and 16, the friction control layer 1 is provided.
00, the friction coefficient of the drive side and driven side members 10, 8 and 16 with which the friction plates 11 and 12 come into contact can be eliminated to control to an appropriate value, and not only a plated layer is formed. Since this plated layer is heat-treated to increase its hardness, it is also resistant to attack, and it is possible to prevent the surface state from changing due to the attack due to the hardening due to the miniaturization of the friction plates 11 and 12, and also to improve durability. It is also possible to maintain the set value of the transmission torque at an appropriate value without failing to be affected by rusting, and to reliably slip due to overload exceeding this set value based on the set transmission torque in advance. Therefore, it is possible to effectively prevent overload. Further, the heat treatment temperature of the plating layer is set to the driving side and driven side members 10, 8, 16 that form the plating layer.
At the austenite transformation point temperature, and the plating layer is diffused and permeated into the surface of the material of the driving-side and driven-side members 10, 8 and 16 so that the surface hardness is Vickers hardness 60.
Since it can be set to 0 or more, the attack resistance and durability can be further improved, and the set value of the transmission torque can be held more effectively and for a long period of time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in FIGS. 1 and 2 is applied to a lever type hoisting / traction machine. First, this lever type hoisting machine will be described. The lever-type hoisting traction machine shown in FIG. 2 has first and second side plates 1 and 2 which are arranged facing each other at a predetermined interval.
In between, a cylinder shaft 4 having a load sheave 3 is rotatably supported, a drive shaft 5 is supported in a central hole of the cylinder shaft 4 so as to be relatively rotatable, and the drive shaft 5 projects toward the second side plate. A reduction gear mechanism 6 including a plurality of reduction gears is interposed between an end portion and the load sheave 3, and the reduction gear mechanism 6 reduces the rotational power of the drive shaft 5 to the load sheave 3 side. The brake receiver 7 and the brake retainer 8 are screwed onto the first side plate side protrusion of the drive shaft 5 and the boss of the brake receiver 7 is transmitted. Brake plates 91, 92 and a braking claw wheel 9 engaging with a braking claw 93 on the outer circumference of the part.
4, the braking plates 91, 92 and the braking claw wheel 94 are interposed between the brake receiver 7 and the brake retainer 8, and mechanical brake 9 is provided by these members.
In addition, on the outer peripheral portion of the brake presser 8,
A drive member 1 which is rotated by a rocking operation of a lever 30 described later.
0 is supported via a one-way rotation transmission mechanism, and a pair of friction plates 11, 11 are provided between the brake presser 8 and the drive member 10.
An overload preventing device 15 including an elastic member 13 mainly composed of a disc spring and an overload setting adjusting member 14 is provided.

The breaker presser 8 has a large diameter portion 81 having a pressing side surface facing one braking plate 92, and a medium diameter portion 82 and a small diameter portion 83 continuous with the large diameter portion 81. And a concave groove 84 for preventing rotation of the holding plate 16 that receives the pressing force of the elastic member 13 and transmits the pressing force to one of the friction plates 12, is provided on the outer periphery of the middle diameter portion 82. The pressing plate 16 is non-rotatably fitted and the small diameter portion 8
Reference numeral 3 designates a rated load at which the overload prevention mechanism 15 starts slipping by adjusting the pressing force of the elastic member 13, that is, the adjusting member 14 for setting the transmission torque from the drive member 10 to the brake presser 8. It is screwed on.

The driving member 10 has a vertical portion 10a.
And a cylindrical portion 10b having a tooth portion 32 to be described later,
An annular recessed portion 17 that opens toward the adjustment member 14 is formed at the center in the radial direction, and one of the friction plate 12 and the pressing plate 16 on one side is housed in the recessed portion 17 and the adjustment member is provided. The elastic member 13 is compressed by tightening 14 to press the friction plate 12 against the drive member 10 via the pressing plate 16, and the large diameter of the brake presser 8 via the drive member 10. The other friction plate 11 interposed between the portion 81 and the vertical portion 10b of the drive member 10 is also brought into pressure contact with the large-diameter portion 81 and the vertical portion 10b, and an overload acts on the drive shaft 5. When the drive member 10
However, the drive member 10 slips relative to the brake presser 8 serving as a follower member so that it can rotate relative to the brake presser 8.
I try to prevent overload.

As a one-way rotation transmission mechanism, FIG.
As shown in FIG. 5, a concave portion 85 is formed on the outer peripheral surface of the medium diameter portion 82 of the brake presser 8 so that the engaging body 86 is constantly urged outward in the radial direction via the spring 87 in the concave portion 85. On the other hand, the engaging member 8 is held on the inner peripheral surface of the driving member 10 while being held.
The engaging groove 19 into which 6 can enter and extends like a wedge in the circumferential direction.
A plurality of (8 in the drawing) are formed, and the drive member 10
6 is rotated in the winding direction shown by the arrow in FIG. 6, the drive member 10 and the brake retainer 8 are integrally connected,
It is possible to deal with a case where a rotational torque larger than the transmission torque of the overload prevention mechanism 15 is required at the time of lowering.

The lever 30 is provided at a position corresponding to an outer portion in the radial direction of the drive member 10 on the outer side of the brake cover 31 which covers the outer peripheral portion of the mechanical brake 9. The tubular portion 10 of the drive member 10
It is provided with a claw body 33 having a forward / reverse claw capable of meshing with a tooth part 32 provided on the outer peripheral part of b, and an operating part 34 for engaging and disengaging the claw body 33 with the tooth part 32. , The nail body 3
The drive member 10 can be rotated in the normal or reverse direction by switching 3 in the above manner.

In the embodiment shown in FIG. 2, the lever type hoisting machine constructed as described above is further provided with a stopper 60 at the shaft end of the drive shaft 5, and the stopper 60 and the Between the brake presser 8 and the brake presser 8 there is a protrusion 44 protruding toward the brake presser 8 and an idle operation handle 40, which cannot rotate relative to the drive shaft 5, is interposed so as to be movable in the axial direction. And the biasing operation handle 40 is urged toward the brake presser 8 side, while the adjusting member 14 drives the brake pressing foot 8 when the idle operation handle 40 is not idle. A rotation restricting means for restricting relative rotation with respect to the shaft 5 at a predetermined angle or more so that the brake presser 8 can be screwed into and out of the brake receiver 7 by relative rotation within a predetermined angle; At the time of idling operation of the operation handle 40,
The tip end surface of the protrusion 44 is elastically contacted by the bias of the operation handle 40 toward the brake presser 8 side to make the brake presser 8
Of the load sheave 3 by suppressing relative rotation with respect to the drive shaft 5, and constitutes a idling device.

This idler will be further described. A serration portion 51 is formed on the drive shaft 5 on the outer side of the brake retainer 8, and the serration portion 51 has a serration portion 51.
The stopper 60 having a large diameter portion 62 having an engaging groove 61 on the outer peripheral portion and a cylindrical portion 63 capable of being coupled to the serration portion 51 is serration-coupled, and the stopper 64 is tightened by tightening a nut 64. It is fixed to the drive shaft 5.

Further, the boss portion 41 of the operation handle 40 is attached to the tubular portion 63, and the fitting hole 42 provided in the boss portion 41.
By fitting the operation handle 40 with the drive shaft 5
Of the stopper 60 is interposed between the large diameter portion 62 of the stopper 60 and the driving member 10 in a state of being movable in the axial direction and rotatable. The extending ridge 43 is provided, and the ridge 43 is engaged with the engaging groove 61 provided on the outer peripheral portion of the large diameter portion 62 of the stopper 60 as shown in FIG. The operation handle 40 cannot be rotated relative to the drive shaft 5.

Also, the boss portion 41 of the operation handle 40.
The stopper 60 that faces the outer peripheral surface of the boss 41 and the boss portion 41.
An elastic pressing member 70 composed of a coil spring is provided between the large diameter portion 62 and the inner side surface of the large diameter portion 62 so as to separate the operation handle 40 from the stopper 60, that is, the blurring direction. In addition to urging toward the presser foot 8 side, a pair of protrusions 44 protruding in the urging direction of the operation handle 40 are provided symmetrically at the radial end on the back side of the boss portion 41.

Further, as shown in FIG. 4, the adjusting member 14 is provided with a pair of notches 21 at symmetrical positions which are 180 degrees out of phase with each other.
As the regulation surface 21a and the other side surface as the second regulation surface 21b,
When the operation handle 40 is not idling operation, the projection 4
4 is located in the cutout portion 21, and relative rotation of the brake presser 8 with respect to the drive shaft 5 within the range of the first and second restricting surfaces 21a and 21b is allowed. When the lever 30 is rocked, the drive member 10 can rotate relative to the operation handle 40, and the brake receiver 7 of the brake presser 8 can be rotated.
The brake retainer 8 can be screwed forward and backward with respect to
By the operation of the mechanical brake 9 by the screwing, the drive shaft 5 can be rotated following the rotation of the drive member 10, and the operation of hoisting or lowering the luggage or pulling or releasing the tow is possible. It becomes.

Further, the adjusting member 14 is provided with the free-rotating member in which the tip end surface of the protrusion 44 is elastically contacted with the adjusting handle 14 in the forward rotation direction side indicated by the arrow in FIG. The holding surface 22 is provided symmetrically with the second restricting surface 21b continuously, so that the holding surface 22 can be brought into the idling state by the operation of the operation handle 40, and the idling state can be held. That is, the drive member 10 is attached to the lever-3.
In a state in which it is rotationally fixed via the claw body 33 of 0, while pulling out the operation handle 40 to the stopper 60 side,
By rotating relative to the drive member 10,
The operation handle 40 is rotated relative to the drive member 10, and the drive shaft 5 is integrally rotated by the relative rotation, and the brake presser 8 screwed onto the drive shaft 5 is rotated.
Is screwed back from the brake receiver 7, and the driving shaft 5 can be idled by this screwing back. At this time, the tip end surface of the projection 44 is biased by the elastic pressing member 70. However, as shown in FIGS.
Since it makes an elastic contact with 2, the operation handle 4 is made by this elastic contact.
0 can be restrained from rotating relative to the brake presser 8, and by this restraint the idle state of the load sheave 3 can be maintained. In FIG. 4, reference numeral 23 indicates that the operation handle 40 is the brake presser 8 and the drive member 10.
It is a rotation restricting portion that prevents the operation handle 40 from being rotated more than necessary due to the contact of the protrusion 44 when rotating.

The operation of the lever-type hoisting / traction machine constructed as described above will be briefly described. The feed claw of the claw body 33 is engaged with the tooth portion 32 of the drive member 10 to perform the operation. By swinging the lever 30, the load sheave 3 is normally driven via the overload prevention device 15, the mechanical brake 9 and the gear reduction mechanism 6, and can be hoisted or pulled. When the load acting on the load sheave 3 exceeds the transmission torque set by the adjusting member 14, a slip occurs between the drive member 10 and the brake retainer 8, and further hoisting / traction is required. Disable it to prevent damage from overload.

Further, the reversing claw of the claw body 33 is engaged with the tooth portion 32 of the driving member 10 and the operating lever 30 is rocked, whereby the operation of the mechanical brake 9 is performed. By rotating the load sheave 3 by a predetermined angle, it can be lowered and pulled. Furthermore, the idling operation is
The reversing claw of the claw body 33 is used as the tooth portion 32 of the drive member 10.
It can be performed by pulling out the operation handle 40 to the stopper 60 side in a state of being engaged with and rotating in the forward direction. That is, by rotating the operation handle 40, the brake presser 8 is axially moved in a direction away from the brake receiver 7, and the mechanical brake 9 can be released by this axial movement. In addition, at this time, the protrusion 44 can elastically contact the freewheel holding surface 22 to maintain the released state of the mechanical brake 9, that is, the freewheeled state.

Next, the lever-type winding-up constructed as described above
The overload prevention device applied to a towing machine will be described with reference to the drawings.

In the above-mentioned overload prevention device, the drive member 10 serves as the drive side member of the present invention, and the brake presser 8 and the presser plate 16 serve as the driven side members. Is used.

In the embodiment shown in the drawings, however, the entire surface of the driving side member 10 and the driven side members 8 and 16, that is,
A plating layer of nickel-phosphorus having a thickness of 8 to 20 μm is formed by electroless plating on the entire surface including the facing surfaces where the friction plates 11 and 12 are in contact, and further in a heating furnace at 300 ° C. for 1 to 2 hours. The friction control layer 100 is formed by heat treatment to have a surface hardness of Vickers hardness of 350 to 450.

As described above, since the friction control layer 100 is formed on the surfaces of the driving side member 10 and the driven side members 8 and 16 facing the friction plates 11 and 12, the surface condition of the material surface, that is, friction. The coefficient can be controlled, and the variation in the coefficient of friction between products can be reduced. By setting the transmission torque by tightening the adjusting member 14, this set value can be properly maintained. Therefore, it is possible to surely slip due to overload exceeding the set transmission torque, and to effectively prevent overload.

Moreover, since the friction control layer 100 is formed not by a simple plating layer but by heat treatment of the plating layer, its surface hardness can be increased, and the friction coefficient can be lowered correspondingly and can be controlled constantly. Therefore, the transmission torque can be set more accurately and there is no variation between products, and the surface condition, that is, the friction coefficient can be prevented from being changed by the attack by the friction plates 11 and 12, and the influence of rusting can be obtained. Therefore, the set transmission torque can be maintained at an appropriate value for a long period of time without being affected.

The heat treatment of the plating layer described above is 300 ° C.
Although it is performed in the heating furnace of,
The heat treatment may be performed for 2 hours. In this case, the surface hardness of the friction control layer 100 is Vickers hardness 400-450.
Can be

Further, the heat treatment temperature of the plating layer is set to the austenite transformation temperature of the material (structural steel) constituting the driving side member 10 and the driven side members 8 and 16, for example, 85.
The friction control layer 100 may be formed by diffusing and permeating the plating layer into the material at 0 ° C. and using the diffusion / permeation layer. In this case, the heat treatment may be performed in a heating furnace, but is preferably performed by high frequency induction heating, and after the heat treatment, quenching is performed by water cooling or oil cooling, and then 200 ° C. to 50 ° C.
It is preferable that tempering is performed at 0 ° C., usually 300 ° C. to 450 ° C. to obtain a martensite structure.

By doing so, the friction control layer 10 is
The surface hardness of 0 is 600 or more of Vickers hardness, for example, 8
It can be 00 to 1,000.

In addition, the embodiment described above is based on nickel.
Although the phosphorus plating layer is formed, it is also possible to form the nickel-chromium or chromium plating layer and heat-treat it to form the friction control layer 100.

Further, although the friction control layer 100 is formed on the entire surface of the driving side member 10 and the driven side members 8 and 16, it may be formed only on the facing surface facing the friction plates 11 and 12. Also, although the overload prevention device applied to the lever type hoisting traction machine has been described, it is also applicable to an overload preventing device for a manual hoisting machine having a handwheel or an electric hoisting traction machine having a motor. Can be applied.

[0035]

As described above, the present invention has the friction plates 11, 12 as described above.
A friction control layer 100 made of a nickel-phosphorus, nickel-chromium, or chromium plating layer, which is heat-treated, is provided on each of the facing surfaces of the driving side member 10 and the driven side members 8 and 16 in contact with each other. Therefore, this friction control layer 10
By setting 0, the surface condition of the facing surface, that is, the coefficient of friction can be controlled, and the variation between products can be reduced, and transmission by tightening the overload setting adjusting member 14 is possible. By setting the torque, this set value can be maintained at an appropriate value, and when the load acting on the load sheave exceeds the preset transfer torque, it will be slipped based on this set value and overload prevention will be effective. You can do it.

Moreover, since the friction control layer 100 is not a mere plating layer but is formed by heat-treating this plating layer, its surface hardness can be increased, the coefficient of friction can be reduced accordingly, and the control can be made constant. Since the transmission torque can be set more accurately and there is no variation between products, it is possible to prevent the surface condition, that is, the friction coefficient, from being changed by an attack by the friction plates 11 and 12. The set transmission torque can be maintained at an appropriate value for a long period of time without being affected by.

Further, the heat treatment temperature of the plating layer is set to the driving side member 10 and the driven side members 8 and 16 for forming the plating layer.
At the austenite transformation point temperature, and the plating layer is diffused and permeated into the surface of the material of the driving-side and driven-side members 10, 8 and 16 so that the surface hardness is Vickers hardness 60.
Since it can be set to 0 or more, the attack resistance and durability can be further improved, and the set value of the transmission torque can be held more effectively and for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

2 is a winding-up application of the overload prevention device shown in FIG.
Sectional drawing of a towing machine.

FIG. 3 is a cross-sectional view of essential parts showing an idle state of the hoisting / traction machine shown in FIG.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is an explanatory view showing an engagement relationship between a free-wheeling handle and a stopper.

FIG. 6 is an explanatory view of a one-way rotation transmission mechanism.

[Explanation of symbols]

 8 Brake Presser (Driven Member) 10 Driven Member 11, 12 Friction Plate 13 Elastic Member 14 Overload Setting Adjustment Member 16 Presser Plate (Driven Member) 100 Friction Control Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Wada 2-180 Iwamuro, Sayama City, Osaka, Osaka Prefecture In the Elephant Chain Block Co., Ltd. (72) Munenobu Honda, 2-180 Iwamuro, Sayama City, Osaka, Osaka In Chen Block Co., Ltd.

Claims (2)

[Claims] 1. A driving side member (10) and a driven side member (8,
16), a friction plate (11, 12) is interposed between the facing surfaces of the driving side member (10) and the driven side member (8, 16), and the friction plate (11, 12) is provided. In the overload prevention device for a hoisting / traction machine, which is provided with an elastic member (13) pressing against each of the facing surfaces and an overload setting adjusting member (14), the friction plates (11, 12) come into contact with each other. A hoisting / traction machine characterized in that a friction control layer (100) is provided on each of the facing surfaces, which is made of a plated layer of nickel / phosphorus, nickel / chromium, or chromium, and the plated layer is heat-treated. Overload prevention device. 2. The heat treatment temperature of the plating layer is set such that the driving side member (10) and the driven side member (8, 1) on which the plating layer is provided.
The friction control layer (100) having the austenite transformation point temperature of 6), wherein the plating layer is diffused on the surface of the material of the driving side and driven side members (10) (8, 16). An overload prevention device for the hoisting / traction machine described.