JPS6253888B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a drive motor rotates a transmission shaft at a reduced speed through a gear system, and a transmission member that performs a linear motion by the transmission shaft and a crank that engages with the transmission member. The present invention relates to an electric operating device that converts the linear motion back into rotational motion of a crankshaft and remotely controls a load switch, a disconnector, etc. via an operating lever coupled to the crankshaft.

Above all, this type of electric actuator is required to operate reliably and to be small and inexpensive. As a conventional electric operating device, one having the configuration shown in FIGS. 1 and 2 is well known. In FIGS. 1 and 2, the speed is decelerated by a pinion 2 installed at the end of the rotor shaft of a reversible rotary drive motor 1 and a gear 3 that engages with the pinion 2, and then transmitted to the transmission shaft 4. A moving nut 5 is fitted into a threaded portion 8 cut in the center of the transmission shaft 4. The pin 13 provided at one end of the moving nut 5 is inserted into a parallel groove of a guide rail 17 arranged parallel to the transmission shaft 4, and is prevented from rotating, so even if the transmission shaft 4 rotates, the moving nut will not rotate. 5 itself does not rotate, but simply moves linearly from side to side on the threaded portion 8 of the transmission shaft 4 by the thrust of the screw. The linear movement of the moving nut 5 is transferred to the crankshaft 7 again via the crank 6 that engages with it.
is converted into rotational motion. As shown in FIG. 1, an operating lever 9 is connected to the crankshaft 7, and the movement of this operating lever 9 is transmitted to operating levers such as load switches and disconnectors via an operating tube (not shown). These can be opened and closed by remote control.

Even if the moving nut 5 disengages from the threaded portion 8 of the transmission shaft 4, the crank 6 will not rotate the crankshaft 7 any further because they are disengaged from each other. Further, the crank 6 does not operate even if an abnormal external force such as an electromagnetic force generated by a short-circuit current of a load switch or a disconnector is applied.

When the moving nut 5 reaches the end of the left and right movement stroke in the threaded portion 8 of the transmission shaft 4, that is, when the crank 6 rotates by a predetermined angle to either the left or right side, the moving nut 5 switches the end limit switch 10. or 10a, also brake switch 11
Or 11a operates. When the end limit switch 10 or 10a operates, the switch of the control circuit is released and the power supply to the drive motor 1 is cut off. Subsequently, the brake switch 11 or 11a is operated, and the braking resistor 15 is applied to the circuit of the drive motor 1, so that the drive motor is rapidly braked. Springs 12 and 12a disposed on both sides of the threaded portion 8 of the transmission shaft 4 prevent the moving nut 5 that has deviated from the threaded portion 8 from rotating the transmission shaft 4 slowly in reverse, for example when manually operating an electric actuator. It is provided so that it can be returned to the threaded portion 8 by. When operating the electric actuator manually, a manual handle is inserted into the shaft end 14 of the transmission shaft 4 and rotated. At this time, a lock switch (not shown) is operated to perform interlock between the electric and manual modes.

In the electric actuator configured as described above, for example, malfunction of the brake switch 11 or 11a,
Alternatively, if the braking circuit is not formed due to a wiring error in the circuit of the drive motor 1, and therefore the drive motor 1 is not braked, the moving nut 5 is This results in deviation from the threaded portion 8 of the shaft 4. When the drive motor 1 is rotated in the reverse direction in this state, even though the springs 12 are arranged on both sides of the threaded portion 8 of the transmission shaft 4, the rotation of the transmission shaft 4 is fast, so that the moving nut 5 and the threaded portion 8
The engagement with the screw inlet is not done smoothly,
There is a drawback that the drive motor 1 is restricted and there is a risk of burnout.

In order to eliminate this drawback in the configuration of a conventional electric actuator, it is necessary to increase the length of the threaded portion 8 of the transmission shaft, and therefore the length of the transmission shaft 4 itself. In order to prevent the strength of the conduction shaft 4 from decreasing due to bending and torsion, the conduction shaft 4 is
It becomes necessary to increase the diameter of the electric actuator, which inevitably increases the external dimensions of the electric actuator as a whole, increases the weight, and increases the cost.

In view of the above-mentioned drawbacks of conventional electric actuators, the present invention aims to prevent the transmission member from constantly deviating from a predetermined relative position with respect to the transmission shaft and the crank when transmitting the rotational force of the drive motor to the crankshaft. It is an object of the present invention to provide a small, inexpensive, and highly reliable electric actuator that does not require a braking circuit for a drive motor.

According to the present invention, the above-mentioned object is to provide the above-mentioned electric actuator, wherein a worm is fixed to the transmission shaft and the operating plate engages with both the crank and a pin provided on a worm wheel which is rotated by the worm. are arranged on both sides of the worm wheel, a recess is provided at the end of the operating plate corresponding to the pin, and a guide provided on a fixed guide plate is provided at the opposite end corresponding to the crank. rollers guided by grooves are respectively disposed, and by driving the drive motor, the worm wheel rotates and the pins fit into recesses in the operating plate to move the operating plate; This is achieved by causing the roller to move along the guide groove and rotating the crank that engages with the roller to drive an operating lever coupled to a crankshaft.

Next, details of the present invention will be explained based on embodiments shown in the drawings.

In FIGS. 3 and 4, a worm 19 is fixed to a transmission shaft 18 that rotates at a reduced speed by a pinion 2 provided at the end of the rotor shaft of the reversible rotation drive motor 1 and a gear 3 that engages with the pinion 2. . Warm 19
A rotating shaft 21 of a worm wheel 20 disposed corresponding to the worm wheel 20 is pivotally supported by a case 40 of the electric operating device. Pins 22 and 22a are fixed to both sides of the worm wheel 20. On the other hand, crank 31,
The fixed crankshaft 30 of 31a is similarly supported by the case 40, and the guide plates 26, 26a are similarly fixedly disposed on the case 40, sandwiching the cranks 31, 31a.

Worm wheel 20 and cranks 31, 31a
Operation plates 23 and 23a are disposed on both sides of the worm wheel 20 in order to interlock the functions. Operation board 2
3, 23a have recesses 41, 41a corresponding to the pins 22, 22a at the worm wheel side ends, and edges of guide grooves 42, 42a provided in the guide plates 26, 26a at the crank side ends. A pin 24 is provided which holds rollers 25, 25a guided along. The inverted V-shaped lower surfaces of the cranks 31, 31a engage rollers 25, 25a, respectively, and as the rollers 25, 25a move along the edges of the guide grooves 42, 42a, they similarly move, thereby causing the cranks to move. The shaft 30 rotates. Operation panel 23, 23a
The lower surface is supported by a torsion spring 29 and a press plate 28 so as to maintain a predetermined position between the worm wheel 20 and the crank 31.

When the drive motor 1 is now driven, the transmission shaft 18 is rotated at a reduced speed via the pinion 2 and gear 3, and the worm wheel 20 is rotated by the worm 19. Then, the pins 22, 22a fixed to both sides of the worm wheel 20 rotate about the worm wheel shaft 21 as shown by the arrows in FIG. The pins 22, 22a are located in the recesses 41 of the operation plates 23, 23a,
41a, the operation plates 23, 23a move to the left in FIG. 3 as the worm wheel 20 rotates. When the worm wheel 20 rotates approximately 180 degrees from the position where it is inserted into the recesses 41, 41a of the pins 22, 22a, the pins 22, 22a
leaves the recesses 41, 41a again. After that, the worm wheel 20 rotates and the pins 22, 2
Even if 2a contacts the operation plates 23, 23a, the operation plates 23, 23a do not close to the guide grooves 42, 4 as shown in FIG.
The rollers 25 and 25a located at the end of the roller 2a only move vertically around the pin 24, but do not move horizontally. If the worm wheel 20 rotates in the opposite direction and the operation plates 23, 23a move to the right, the sixth
As shown in the figure, the rollers 25, 25a are connected to the guide groove 42,
Similarly, the operating plates 23, 23a only move up and down by being located at the end opposite to the former of 42a.

As described above, the operation plates 23, 23a move to the left and the rollers 25, 25a move along the lower edges of the guide grooves 42, 42a from one end of the guide grooves 42, 42a to the other end. Possibly roller 2
The cranks 31, 31a engaged with the cranks 5, 25a also rotate to the left, and the crankshaft 30 coupled to the cranks 31, 31a rotates. When the crankshaft 30 rotates, as shown in FIG. 4, the control levers 33, 33a
is operated, and the control levers of the load switch and disconnector are operated via a control tube (not shown) to open and close them by remote control.

After the cranks 31, 31a rotate a predetermined angle and the rollers 25, 25a reach either end of the guide grooves 42, 42a, they are stopped by a short-circuit current from a load switch or disconnector during closing, for example. As shown in FIG. 7, the lower edge surfaces 44, 44a at both ends of the guide grooves 42, 42a are shaped in a predetermined manner so that the crank 31 can be completely held in a predetermined position even if an abnormal external force such as a generated electromagnetic force is applied. Crank 31, 31 in position
Is it parallel to the lower surface 43 of the inverted V shape of a?
Alternatively, it is inclined so that it opens by a small angle O. Furthermore, a roller 2 is provided to determine the final position of the operation plates 23, 23a so that the pins 22, 22a can be accurately inserted into the recesses 41, 41a of the operation plates 23, 23a when the worm wheel 20 is rotated forward or backward.
5, 25a are pressed against both end surfaces 4 of the guide grooves 42, 42a by a restraining spring 27 provided on the crankshaft 30.
5, 45a or 46, 46a, the restraining plate 28 supports the operating plates 23, 23a at a predetermined position by the torsion spring 29.

When manually operating the device of the present invention, the transmission shaft 18
Simply insert the manual handle 36 into the transmission shaft, engage the groove at the tip of the manual handle 36 with the pin 39 provided on the transmission shaft, and turn it. At this time, the lock switch 38 is operated via the lever 37 to perform interlock between the electric and manual modes. The final position of rotation of the crankshaft 30 in the manual case can be detected by a switch 34 operated by a lever 35 fixed thereto.

As explained above, the drive motor decelerates and rotates the transmission shaft through the gear system, and the linear motion is again caused by the transmission member that performs linear motion by the transmission shaft and the crank that engages with the transmission member. In an electric operating device that converts rotational motion of a crankshaft into remote control of a load switch, disconnector, etc. via an operating lever coupled to the crankshaft, a worm is fixed to the transmission shaft, and the worm An operation plate that engages both a pin provided on a worm wheel to be rotated and the crank is arranged on both sides of the worm wheel, and a recess is provided at the end of the operation plate corresponding to the pin, and a recess is provided on the opposite side. Rollers guided by guide grooves provided on a fixed guide plate are disposed at the end corresponding to the crank on the side, and by driving the drive motor, the worm wheel rotates and the pin is rotated. is inserted into the recess to move the operating plate, and at this time, the roller moves along the guide groove and rotates the crank that engages with the roller to drive an operating lever coupled to the crankshaft. By doing so, when transmitting the rotational force of the drive motor to the crankshaft, the operation plate does not always deviate from the predetermined relative position with respect to the transmission shaft and the crank, and therefore the drive motor Since there is no need to provide a braking circuit, the electric actuator can be made smaller and less expensive, and its reliability can be improved.

[Brief explanation of the drawing]

1 and 2 are a plan view and a side view schematically showing the structure of a conventional electric operating device, and FIGS. 3 and 4 are a side view and a front view schematically showing the structure of the electric operating device of the present invention. represents a diagram. FIGS. 5 and 6 are schematic diagrams showing the relative relationships among the pin, the operating plate, and the crank at the final position of the operating plate when the worm wheel rotates forward and backward, respectively, in the electric operating device of the present invention. FIG. 7 is a schematic view showing the relative relationship between the rollers, guide grooves, and crankshaft restraining springs in FIG. 6. DESCRIPTION OF SYMBOLS 1... Drive motor, 2, 3... Gear device, 18... Transmission shaft, 19... Worm, 20... Worm wheel, 22, 22a... Pin, 23, 23a... Operation plate, 25, 25a... Roller, 26, 26a... Guide Plate, 30... Crankshaft, 31, 31a... Crank, 33, 33a... Operating lever, 41, 41a...
Recess of operation plate, 42, 42a... guide groove of guide plate.

Claims (1)

[Claims] 1. The drive motor decelerates and rotates the transmission shaft via a gear system, and the linear motion is returned to rotation of the crankshaft via a transmission member that performs linear motion by the transmission shaft and a crank that engages with the transmission member. A worm is fixed to the transmission shaft and rotated by the worm in an electric operating device that converts motion into motion and remotely controls a load switch, disconnector, etc. via an operating lever coupled to the crankshaft. An operation plate that engages both a pin provided on the wheel and the crank is arranged on both sides of the worm wheel, and a recess is provided at the end of the operation plate corresponding to the pin, and a recess is provided at the end corresponding to the crank on the opposite side. A roller guided by a guide groove provided on a fixed guide plate is arranged at each end corresponding to the
By driving the drive motor, the worm wheel rotates and the pin fits into the recess to move the operation plate, at which time the roller moves along the guide groove and engages with the roller. An electric operating device configured to rotate the crank and drive an operating lever coupled to a crankshaft.