JPH07117991A - Variable-speed electric hoist - Google Patents

Abstract

PURPOSE:To provide a push-button-operated variable-speed electric hoist capable of being operated at a variable speed, capable of being safely operated regard less of a work object, and excellent in operability. CONSTITUTION:A hoisting/lowering motor 1 is voltage-controlled when the resistance value is changed. This variable-speed electric hoist is arranged with two hoisting/lowering push buttons 22, 23 nearby on the operation face 24a of an operation section 21, and racks 25a, 26a are moved when two push buttons 22, 23 are pushed. When a pinion 33 arranged between the racks 25a, 26a to be meshed with them is rotated, an interlocked variable resistor 34 is operated to change its resistance value. The moving range of the push buttons 22, 23 is limited within a prescribed range, and they are automatically returned by compression springs 29, 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric hoist, and more particularly to a variable speed electric hoist capable of controlling the hoisting / lowering speed of the electric hoist by pressing a fingertip.

[0002]

2. Description of the Related Art Conventionally, an electric hoist such as an electric chain block generally has a push button switch hung from a hoist main body via a cable. By pushing the upper command button and, in the case of the lowering operation, pushing the lower command button of the push button switch, the electromagnetic contactor is controlled to change the rotation direction of the electric motor.

Further, as a variable speed type electric chain block capable of changing from a low speed to a high speed, a speed designating operation section composed of a variable resistor is provided in a push button switch section,
By operating the speed specification operation unit, a signal is sent to the voltage control unit built in the hoisting machine main body, the applied voltage of the electric motor is changed to variably control the rotation speed, and the speed can be arbitrarily set. What you have done is known.

Further, the electric chain block which can be operated while varying the speed is a hand-operated system in which an operating portion is provided on a suspender engaged between a chain and a load suspending hook. The resistance value is changed by rotating the knob of the part to the left and right during hoisting and hoisting operations respectively, and as in the above-mentioned variable speed type electric chain block, the rotational speed of the electric motor is variably controlled to enable variable speed operation. It is known that it is possible.

Here, the above-mentioned three types of conventional techniques will be described in more detail with reference to FIGS. 13 to 15.

In FIG. 13, a chain block as an electric hoist according to a conventional example is a hoisting / lowering electric motor 1.
And an electric component storage section 2 for accommodating various electric components provided at one end of the hoisting / lowering electric motor, and an electric motor integrally attached to the main body of the hoisting / lowering electric motor 1. An upper hook 3 for suspending a chain block including 1 on a structure on the ceiling and a hanging part from the electrical component housing 2 for transmitting a signal from a chain block operating unit 8 described later to electrical components in the hoisting machine body. A cable 4, a chain 5 extending from the hook 3 side, a lower hook 6 for hanging a load, a lifting tool 7 for connecting the lower hook 6 to the chain 5, and a chain block operating part 8 attached to the lower end of the cable. Consists of
By pushing the up button 8a or the down button 8b of the operation unit 8, the hoisting / lowering electric motor 1 can be driven to lift or lower the luggage 9 hooked on the lower hook 6. .

Next, the conventional example shown in FIG. 14 will be described. In the variable speed electric chain block of FIG. 14, an operating section 10 is used in place of the operating section 8.
With the change of 0, the control unit 13 provided in the electric component storage unit 2 is different only in accordance with the configuration of the control unit 10, and other configurations are the same as those of the conventional example shown in FIG. Has become.

In this prior art example, the operating portion 10 has push-button switches 11a and 11b for instructing hoisting / lowering and a variable resistor (not shown), and further, a knob is operated from the outside. It has a speed designation operation unit 12 that can be variably operated. The control unit 13 is configured to change the hoisting / lowering command and the voltage applied to the electric motor 1 according to signals from the push button switches 11a and 11b and the speed command operating unit 12, and the speed designating operation unit 12 is controlled. By operating and variably designating the resistance value of the variable resistor, the applied voltage to the electric motor 1 is changed to change its rotation speed, and an arbitrary speed is selected.

Further, the conventional example shown in FIG. 15 will be described. In the variable speed electric chain block according to this conventional example, the hand operation part 14 is attached to the hanging tool 7 for connecting the chain 5 and the load hanging hook 6. The work unit 14 provided integrally is provided with a grip 15 that serves as a grip for facilitating the support of the hanging device 7, and an operation knob 16 that gives a hoisting / lowering command and a variable speed command. The operation knob 16 is used as a hoisting / lowering command, and the resistance value of a built-in resistor (not shown) is changed by rotating left and right from the neutral position, and the signal is transmitted to the control unit 17 to drive the electric motor. A variable speed operation is performed by changing the voltage applied to the motor and the rotational speed.

A variable speed electric hoisting machine disclosed in JP-A-63-262393 and a speed control device for a mobile machine described in JP-A-4-45100 are also known. JP-A-6
The invention described in 3-262393 has two resistors for low speed and high speed for setting the speed of the continuously variable transmission mechanism.
A combination of a step-pushing type pendant switch and a relay is configured so that the first stage of the pendant switch is connected to a low speed resistor and the second stage is connected to a high speed resistor. Further, the invention described in Japanese Patent Application Laid-Open No. 4-45100 outputs a speed command push button having a plurality of pressing steps, and outputs a speed command according to the pressing step of the speed command push button, and changes the pressing step. Occasionally, a speed designation output means or the like for softening and outputting the change in the speed command value is provided, and for example, the operation is switched to a low speed operation in the first step, a low speed operation in the second step, and a high speed operation in the final step.

[0011]

By the way, among the above-mentioned prior arts, the general electric chain block shown in FIG. 13 is currently most frequently used, so there is no particular problem. , The moment when the luggage leaves the ground, or the floor, stand, etc. (usually called off-ground),
If you carry out hoisting operation at once, the luggage will shake and it will be in a dangerous state, so in order to avoid this danger and further to eliminate the problem of premature wear of the equipment due to the impact when leaving the ground It is customary to perform an inching operation.
Needless to say, this inching operation is performed when descending. Otherwise, the luggage will often be damaged when landing.

As described above, in the general electric chain block shown in FIG. 13, since it is necessary to perform the inching operation, the work efficiency is lowered and the number of times of starting and stopping is increased, so that the electrical contact of the operating portion is changed. Initially, this results in faster wear of each part. Also, depending on the type of work, such as chemicals, explosives, and other dangerous materials, as well as precision assembly of parts, die matching work represented by a press die, and dipping work of parts into a plating tank,
It is necessary to finely adjust the speed of the electric chain block, and with the general electric chain block shown in FIG. 13, it is necessary to have the skill to perform the above work, and anyone can easily perform the above work. I couldn't do it.

On the other hand, in the variable speed type electric chain block shown in FIG. 14, it is satisfactory in that the best arbitrary speed can be selected depending on the kind and application of the luggage, but this is just an arbitrary speed. It is selected and set, and is not used while changing the speed during operation. Therefore, it is satisfactory in use in applications where it is necessary to use both low speed and high speed, such as low speed operation at the time of landing / landing or precision assembly of parts, and high speed operation at other times. It wasn't possible.

Furthermore, the hand-operated electric chain block shown in FIG. 15 is effective when used in a product assembly line or the like, which has a relatively short moving distance and a lot of goods are transshipped.
Also, since it is possible to operate while varying speed, you can freely use it according to your work, from low speed operation to high speed operation,
It is very easy to use, but since it can be operated only within the reach of the user, it has a long travel distance (lift) that accounts for most of the applications in the market, and because the luggage is large or dangerous. In many cases, it was difficult to use when it was not possible to approach, and the work that could be used was limited.

Further, in the invention described in Japanese Patent Laid-Open No. 63-262393, the speed control is performed at a variable speed, but the low speed and the high speed can be selectively used by the pushing operation of the first step and the second step. It is constructed and cannot perform delicate speed control. Therefore, the inching operation does not become unnecessary. This is also the case with the invention described in Japanese Patent Application Laid-Open No. 4-45100, and delicate operation cannot be performed as long as continuously variable speed is not possible.

The present invention has been made in view of the above-mentioned state of the art, and its object is a push-button operation type that is most commonly used and evaluated, and can be operated while varying the speed. Another object of the present invention is to provide a variable speed type electric hoisting machine which can be operated safely and can be operated safely without selecting a work target.

[0017]

In order to achieve the above-mentioned object, the present invention is directed to suspending an operation box from a main body of an electric hoist via a cable and operating an operation button provided in the operation box to operate the cable. In a variable-speed electric hoist that performs work by changing the hoisting and hoisting speeds, the hoisting direction instructing push button and the hoisting direction instructing push button, which are independently provided close to the operation surface of the operation box, are provided. A button, resistance varying means for continuously changing the resistance value by pressing the hoisting direction instructing push button and the lowering direction instructing push button, and a voltage applied to the electric motor according to the resistance value changed by the variable resistance means. When the control means for controlling and one of the push-up button for instructing the winding direction and the push-button for instructing the winding direction is pressed, the operation of the other push button for instructing is substantially It is characterized in that a interlock means for disabling the.

In this case, the resistance varying means includes a variable resistor, a pinion that interlocks with the variable resistor, and a pair of racks that interlock with the operation button that meshes with the pinion and rotationally drives the pinion. Each of the operation buttons is composed of spring means for constantly elastically urging in the initial position direction, the interlock means is provided with the pinion and the pinion sandwiched, and the operation button is preliminarily provided from the initial position. The rack can be configured to mesh with the pinion when the stroke is pushed and drive the pinion. Further, the resistance varying means may be configured by combining a rotation angle detecting sensor, an optical sensor detecting a slide movement amount, a magnetic sensor, and the like, and a resistance value conversion circuit converting the detection output of these to a resistance value.

[0019]

According to the above construction, by arranging the two push buttons for the hoisting / lowering operation close to the same operation surface of the operation box, the operation box is supported by the fingertips. The two push buttons can be easily used properly, and the operation section is similar to the push button switch that is widely used and appreciated. The variable speed operation command is performed by pushing or pressing the push button with the fingertip, that is, by driving the resistance variable means by the pressing force, and therefore the movement of the hand to be operated is small, and only the fingertip can be operated at the speed desired by the operator. It can be operated, can be operated at any optimum speed, and can be used for a wide range of applications.

Further, since the interlocking means is constructed so that the above-mentioned pushbutton for instruction does not function depending on an instruction by the other pushbutton when one pushbutton is operated, an operation mistake can be avoided and a safe work can be performed. Is possible. In addition, when the variable resistance means and the interlock means are configured mechanically, for example, only by disposing the pinion and the rack or setting the meshing state so that other operations of the variable resistance means cannot be performed while the variable resistance means is being operated. The mechanism is simple, the cost is low, and the breakdown is few.

In this case, the interlock means prevents the rack and the pinion from meshing when the rack is meshed with the pinion sandwiched therebetween and the push button is not operated, and the push button is in the initial position. Position both so that the rack can engage the pinion when pushed in a little. As a result, when one of the push buttons for operation is pushed in, the rack corresponding to the push button meshes with the pinion, and the pinion is rotated. If another push button is pushed in this state, the push button cannot be pushed in from the position where the rack interlocking with the push button is in contact with the pinion, so that the rack is substantially locked.

When the finger is released from the push button for moving the rack on the side engaged with the pinion from this position, the elastic biasing force of the spring means returns the operation button to the initial position, whereby the rack on the push button side is moved. Since the meshing between the pinion and the pinion is released, the rack can be meshed with the pinion interlocked with the other push button by pressing the other push button. That is, the lock is released when the push operation of the push button is stopped, and the lock of the other push button is locked when the push button of one push button is engaged with the pin-on. As a result, the variable resistance means and the interlock means are realized by the same mechanism.

As the interlock means, a microswitch may be combined and electrically configured to open the circuit when the instruction push buttons are simultaneously operated.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the internal structure of the operating portion of the electric chain block according to the first embodiment, and FIG. 2 is shown in FIG.
FIG. 3 is a left side view in which a main part of the electric chain block is cut away, FIG. 3 is a perspective view showing a schematic configuration of an outer appearance of an electric chain block incorporating an operation unit according to this embodiment, and FIG. 4 is an electric diagram of the electric chain block according to this embodiment. FIG. 5 is a circuit diagram for explaining the operation of the rotary variable resistor according to this embodiment.

As can be seen from FIG. 3, the cable 2 can be seen from the electrical equipment housing 2 of the electric chain block according to the first embodiment.
0 is hung down, and the operation box 21 is attached to the lower end of the cable 20.
Is attached. Further, a power supply cable 18 extends from the electric component storage unit 2 so that electric power can be supplied to the electric component storage unit 2. Other parts are shown in FIG.
Since the third embodiment has the same configuration as the conventional example, the same reference numerals are given to the respective parts that can be regarded as the same, and the duplicated description will be omitted.

As shown in FIGS. 1 and 2, the operating portion 21 is formed in a box shape by screwing an upper case 24 and a lower case 32, and is formed on the operating surface 24a of the upper case 24 on the left side in FIG. The hoisting operation push button 22 and the hoisting operation push button 23 are arranged so as to be close to each other in the upper and lower directions in consideration of operability and can be pushed into the upper case 24. On the back side of the two push buttons 22 and 23, operation members 25 and 26 having racks 25a and 26a respectively cut are attached by screwing. These operation members 25 and 26 include stopper portions 25b and 26, respectively.
b and bearings 25c and 26c are provided. The stopper portions 25b and 26b are flange-like protrusions from the end portions of the operating members 25 and 26 on the lower case 32 side,
The bearings 25c and 26c are provided substantially along the axis of the operating members 25 and 26. The bearings 25c and 26c are slidably fitted onto support pins 27 and 28 provided upright on the inner surface of the lower case 32, and are constantly elastically biased toward the upper case 24 by compression springs 29 and 30. Push buttons 22, 23
Is a bearing 2 provided in a hole formed in the upper case 24.
The bearings 25d and 26d are slidably guided and supported by the bearings 25d and 26d. The support pins 27, 28 are fixed to the inner surface of the lower case 32 by screwing, as can be seen from FIG.

A pinion 33 is arranged between the two operating members 25 and 26, and the racks 25a and 26a are engaged with each other with the pinion 33 interposed therebetween. In the initial state shown in FIG. 1, these racks 25a and 26a are not in mesh with the pinion 33, and the push button 2
It is formed so that the first and second teeth 23 and 23 are pushed in to engage with each other. The drive shaft of the movable contact of the rotary variable resistor 34 is connected to the rotary shaft of the pinion 33. The rotary variable resistor 34 is fixed by tightening a nut 36 to a support 35 screwed to the inner surface of the upper case. The support 35 also includes the operation member 2
Through holes through which the holes 5 and 26 penetrate are formed, and the stopper portions 25b and 26b respectively contact the edges of the through holes to define the initial positions of the push buttons 22 and 23.
As a result, the push buttons 22, 23 or the operation member 2
5 and 26 are movable between the positions where the stoppers 25b and 26b contact the support 35 and the tips of the support pins 27 and 28 contact the bottoms of the bearings 25c and 26c. The support 35 has pushbuttons 22 and 23.
Two micro switches 37 and 38 are attached, which are operated by pushing in.

Next, the operation of the variable speed electric chain block according to the embodiment will be described with reference to the circuit diagram of FIG. First, for example, when the push button 22 for hoisting operation is pushed to pull up a load, the micro switch 37 operates, the relay coil 39 is excited, and the relay contact 41 is closed via the control unit 17 and the rectifier 40. The hoisting / lowering electric motor 1 starts to rotate in the hoisting direction. When it is further pushed in, the pinion 33 meshes with the movement of the rack 25a and rotates right in FIG. 1, and the rotation angle of the pinion 33 increases according to the pushing amount. Then, the movable contact of the rotary variable resistor 34 connected to the pinion 33 also rotates in conjunction, and the resistance value gradually decreases from the state of the maximum resistance value, as is clear from FIG. Then, by the voltage control of the control unit 17, in the case of the maximum resistance value, the applied voltage of the hoisting / lowering motor 1 is the minimum, and the speed is the lowest because of the lowest speed rotation. The applied voltage gradually rises due to the decrease of, and the rotation speed rises. As a result, the speed is increased, and eventually the maximum speed is obtained when the minimum resistance value is obtained.

Further, when the push-down operation push-button 23 is operated, when the push-down operation push-button 22 is operated, the relay coil 44 is excited this time and the relay contact 45 is closed, and the winding-up / down-winding operation is performed. The electric motor 1 starts to rotate in the unwinding direction, and the stroke of the rack 26a increases in accordance with the pushing amount, and accordingly, the rotation angle of the pinion 33 also increases in the opposite direction. Then, contrary to the above, the speed on the descending side is controlled. Incidentally, reference numeral 43 in the figure is a commercial power source.

In the above structure, the operating members 25, 26
As for the relationship between the racks 25a, 26a, the pinion 33, and the rotary variable resistor 34 provided in the above, since the tooth number ratio of the two can be arbitrarily determined, the rotary variable resistor having a small shape with a small stroke of the push buttons 22 and 23 is provided. It is possible to obtain a large change in resistance value from the device 34. Also, rack 25
Since the meshing lengths of the a and 26a and the pinion 33 can be arbitrarily determined, a standard variable resistor (for example, 0 to 100 kΩ or the like) whose resistance value is regulated is used to obtain a required resistance value (for example, a predetermined speed). 5 to 50 kΩ for the range
It is also possible to obtain the lowest speed and the highest speed that meet the product specifications. Further, since the single rotary variable resistor 34 is shared for the hoisting / lowering operation, the operating portion can be downsized.

In addition, the pinion 33 is an operation member 25, 26.
Moves to engage with the racks 25a and 26a for the first time. Therefore, when one push button 22 (23) is pushed in, the other push button 23 (22) does not protrude, but one push button Push the button 22 (23) to push in the rack 25a of one push button 22 (23).
(26a) and the pinion 33 mesh, the rack 26a operated by the other push button 23 (22)
Since (25a) cannot mesh with the pinion 33, the other push button 23 (22) cannot be pushed in, and the interlock is applied.

Further, since the two push buttons 22 and 23 are elastically biased by the compression springs 29 and 30 so as to always return to the initial state, the push buttons pushed in the opposite direction instantly when the hands are released. It returns to the original state and operation stops immediately. This prevents the chain block from running out of control.

The projection 42 provided on the upper case 24
Is for protecting the push buttons 22 and 23, and is effective for protecting the push buttons when the operating portion collides with a wall or the like, and is shown in the figure.

FIG. 6 is a perspective view of the operating portion of the electric chain block according to the second embodiment. In the second embodiment, the present invention is applied to a hand-operated type electric chain block, and a push-up button 22 for a hoisting operation and a push button 23 for a lowering operation are provided on an operation surface 14a of a hand-side operation section 14. Are arranged side by side. In this case, the installation direction and the installation position of the operation member and the rack are different from those of the first embodiment due to the change of the arrangement of the push buttons 22 and 23, and the configurations and functions of other parts are the same as those of the first embodiment. Is equivalent.

FIG. 7 is a sectional view of a main part showing the internal structure of the operating portion of the electric chain block according to the third embodiment. In this embodiment, the rotation amount detection sensor 50 is used to detect the rotation of the rotation pinion 33, and the rotation amount from the initial position where the push buttons 22 and 23 are not pushed is detected, and the rotation amount is detected by the control unit. The rotation amount input to the control unit 17 and input by the resistance value conversion circuit in the control unit 17 is converted into a resistance value, and the same voltage control as described above is performed based on the resistance value. The micro switches 37 and 38 detect which of the push buttons 22 and 23 is pressed. The push switches 22 and 23 and the rotation amount detection sensor 50 detect the amount of rotation of the electric switch. It is possible to set the rotation direction and the rotation speed of the container 1. As the rotation amount detection sensor 50, a known non-contact type sensor such as an optical rotary encoder or a magnetic rotary encoder is used. Each part that is not particularly described has the same configuration as that of the first embodiment described above.

FIG. 8 is a sectional view showing the internal structure of the operating portion of the electric chain block according to the fourth embodiment. In this embodiment, the push-in amounts of the push buttons 22 and 23 are directly converted into linear movement amounts without being converted into rotation amounts. More specifically, the push button 22,
23 is provided with a slide member 51 on the back side, and a detection member (slit) 52 is joined to the slide member 51.
The amount of light that passes through the window portion 53 of the isosceles triangle, which is provided in the detection member 52 as shown in the plan view of the main part of FIG.
4 and a light receiving element 55 are used for detection. That is, by forming the window portion 53 as described above, the light amount that increases according to the pushing amount of the push buttons 22 and 23 is detected as an electric signal by the light receiving element 55 and is taken into the control unit 17, and the inside of the control unit 17 is detected. The resistance value conversion circuit converts the resistance value into a resistance value and controls the voltage of the hoisting / lowering motor 1. In this case, the slide member 5
1 is a projection-like guide protrusion 56 fitted in the center thereof,
A guide plate 57 that supports and guides the free end of the detection member 52 is guided to move linearly. The end of the detection member 52 is always elastically biased by the compression spring 58 toward the initial position of the push buttons 22 and 23.

In this embodiment, the microswitch "upper" 37 'and the microswitch "lower"38' are 37'-1, 38'-1, 37'-2, 38'- in FIG.
As shown in FIG. 2, there are two sets of contact points.
As shown in the circuit diagram of FIG.
38'-1, 37'-2 and 38'-2 are connected. As a result, when the micro switches 37 'and 38' are turned on at the same time, the circuit is cut off, the operation of the electric motor 1 is stopped, and the operation is locked.

In addition, all other parts which are not particularly described are constructed in the same manner as in the first embodiment. It goes without saying that a reflecting plate of the same shape may be attached as the detection member 52 instead of the window portion 53, and a reflection type optical sensor may be introduced instead of the transmission type optical sensor.

FIG. 11 is a sectional view showing the internal structure of the operating portion of the electric chain block according to the fifth embodiment. In this embodiment, like the fourth embodiment, the push buttons 22, 2
The pushing amount of 3 is detected as a linear movement amount as it is without being converted into a rotation amount. In this embodiment, operating members 61 and 62 are provided behind the push buttons 22 and 23 in the same manner as in FIG.
The magnet elements 61a and 62a are attached instead of a, and the Hall element 63 is installed on the inner surface of the lower case 32. The hall element 63 includes both magnet elements 61a,
62a are provided at positions equidistant from each other. The hall element 63 is a magnet element 61a, 62.
a is detected as an electric signal proportional to the moving magnetic flux density and changes, and is taken into the control unit 17, and the control unit 17 is configured to convert the resistance value into a resistance value by the resistance value conversion circuit to control the voltage of the electric motor 1. There is. The micro switch 3
7'and 38 'are the same as those in the fourth embodiment, and the interlock is also electrically applied in the same manner as in the fourth embodiment. Other parts, which are not particularly described, are configured in the same manner as in the first embodiment.

The third, fourth and fifth embodiments exemplify detection means such as a rotation detector, an optical sensor, or a hall element, but in addition to this, pushbuttons are also provided. It goes without saying that the same configuration can be achieved using various known sensors such as a pressure sensor that directly converts the pressing force of 22 and 23 into an electric signal.

[0042]

As is apparent from the above description, according to the present invention configured as described above, the two operation units for hoisting and unwinding operations are brought close to the operation surface which is the front surface of the operation section. By arranging the pushbuttons for instruction, the two pushbuttons can be easily used with the fingertips while the operating part is supported by the palm of the hand, and the pushbutton switch type is widely used and popular. You can operate in the same way as the above, and the variable speed operation command can be issued by pressing the instruction button with your fingertips, so there is little movement of the hand during operation, and you can adjust the speed as you want according to the application and driving condition. It is possible to freely operate with, and realize optimal cargo handling work. At that time, even if the two instruction buttons are accidentally pressed at the same time, the instruction of the instruction button at least pressed later by the interlock means is not transmitted to the control means side, so that the motor does not run away and the speed can be changed safely. You can work while

That is, according to the present invention, it is possible to provide a variable speed electric hoist having excellent operability which enables safe variable speed operation without selecting a work target.

[Brief description of drawings]

FIG. 1 is a main-portion cross-sectional view showing the structure of an operating portion of an electric chain block according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of an essential part of the operating portion of FIG. 1 viewed from the left side surface.

FIG. 3 is a perspective view showing an outline of the entire electric chain block incorporating the operation unit according to the first embodiment.

FIG. 4 is a circuit diagram showing an electric circuit applied to the electric chain block according to the first embodiment.

FIG. 5 is an explanatory diagram showing the operation of the rotary variable resistor used in the first embodiment.

FIG. 6 is a perspective view showing an operating portion of an electric chain block according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view of essential parts showing the structure of an operating portion of an electric chain block according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional view of essential parts showing the structure of an operating portion of an electric chain block according to a fourth embodiment of the present invention.

9 is an enlarged plan view of an essential part showing details of a detection unit in FIG.

FIG. 10 is a circuit diagram showing a structure of a micro switch of an operating portion of an electric chain block according to a fourth embodiment.

FIG. 11 is a cross-sectional view of an essential part showing the structure of the operating portion of the electric chain block according to the fifth embodiment of the present invention.

FIG. 12 is a circuit diagram showing an electric circuit applied to an electric chain block according to a fourth embodiment.

FIG. 13 is a front view showing a schematic configuration of an electric chain block according to a conventional example.

FIG. 14 is a front view showing a schematic configuration of a variable speed electric chain block according to a conventional example.

FIG. 15 is a front view showing a schematic configuration of a conventional hand-operated electric chain block.

[Explanation of symbols]

 1 Hoisting / Unwinding Motor 2 Electrical Equipment Storage Section 3 Upper Hook 4 Cable 5 Chain 6 Lower Hook 7 Lifting Equipment 8 Operating Section 14 Operating Section 14a Operating Surface 17 Control Section 21 Operating Section 22 Pushing Operation Button 23 Push-down button for lowering operation 24 Upper case 24a Operation surface 25,26 Operation member 25a, 26a Rack 25b, 26b Stopper section 25c, 26c (Receiving support pin) Bearing 25d, 26d (Receiving push button) Bearing 27, 28 Support pin 29, 30 Compression spring 32 Lower case 33 Rack 34 Rotating variable resistor 37, 37 ', 38, 38' Micro switch 50 Rotation amount detection sensor 51 Sliding member 52 Detection member 53 Window 54 Light emitting element 55 Light receiving element 61, 62 Operation member 61a, 62a Magnet element 63 Hall element

Claims (7)

[Claims] 1. A variable speed type in which an operation box is hung from a main body of an electric hoist via a cable and an operation button provided on the operation box is operated to change a winding speed and a lowering speed of the cable to perform work. In an electric hoisting machine, a push-up button for instructing a winding direction and a push-button for instructing a winding-down direction, which are independently provided in the vicinity of an operation surface of an operation box, and the push-button for instructing a winding-up direction and a winding-down direction. Resistance changing means for continuously changing the resistance value by pressing the operating push button, control means for controlling the voltage of the electric motor according to the resistance value changed by the variable resistance means, the winding direction indicating push button and the winding Interlocking means for substantially disabling the operation by the other instruction push button when one of the lower direction instruction push buttons is pressed. Variable speed form electric hoist according to claim Rukoto. 2. The variable speed electric hoisting machine according to claim 1, wherein the resistance varying means is a variable resistor whose resistance value changes in accordance with the pushing amount of the instruction push button. 3. The variable resistance means includes: a variable resistor; a pinion that interlocks with the variable resistor; and a pair of racks that interlock with the instruction push button that meshes with the pinion and rotationally drives the pinion. , Each of the instructing pushbuttons is always elastically biased toward the initial position, and the interlocking means is provided so as to sandwich the pinion and the pinion, and the instructing pushbutton is moved from the initial position. 2. The variable speed electric hoisting machine according to claim 1, further comprising: the rack that meshes with the pinion and drives the pinion when the previously-entered stroke is pushed. 4. The resistance varying means comprises a rotating body that rotates in accordance with the amount of depression of the instruction push button, and a resistance value conversion circuit that converts the amount of rotation of the rotating body into a resistance value. The variable speed electric hoisting machine according to claim 1. 5. The resistance variable means is a detection plate that slides according to the amount of depression of the instruction push button, and is provided on the detection plate, and detects according to the amount of movement of the detection plate from the initial position. A detection unit formed to increase the amount of light, an optical detection element that converts the amount of light input from this detection unit into an electrical signal, and the electrical signal converted by this optical detection element is further converted into a resistance value. The variable speed electric hoisting machine according to claim 1, comprising a resistance value converting circuit for converting. 6. The detection section comprises any one of a slit and a reflector formed as one apex sandwiching one point located on the downstream side in the pushing direction with equilateral sides of an isosceles triangle. The variable speed electric hoisting machine according to claim 5. 7. A detection plate, in which the resistance varying means slides in accordance with the amount of depression of the instruction push button, magnet elements provided on the detection plate, and movements of these magnet elements. 2. A hall element for detecting a change in magnetic flux and converting it into an electric signal, and a resistance value conversion circuit for further converting the electric signal converted by the hall element into a resistance value.
Variable speed electric hoist as described.