JP3802459B2 - Screw actuator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screw operating device that can smoothly move a moving body that mainly moves linearly by converting rotational power into linear motion and that can control the traveling range of the moving body.
[0002]
[Prior art]
Conventionally, in an apparatus that reciprocates a required section, for example, an automatic door, the door is opened and closed by winding driving with a chain or an endless belt. For this purpose, the suspension member is moved along the guide rail at a relatively low speed from the motor via the speed reducer inside the box structure, and the door attached to the suspension member is opened and closed. ing.
[0003]
Such an endless belt drive type automatic opening / closing door device is known, for example, from JP-A-7-197731. What is disclosed in this publication is a door pulley in which a door suspension is connected to an endless belt driven by a motor, and is attached to the suspension by a belt driven from a motor through a speed reducer at a required speed. The door can be opened and closed by rolling on the guide rail.
[0004]
In addition, a screw type automatic door is known from Japanese Patent No. 2647329. This screw type automatic door is operated by screwing a ball screw shaft and a nut member connected to the door, and allows a drive shaft (screw shaft) having the screw groove to rotate in both directions. A clutch having a first position (lock release position) and a second position (lock position) allowing rotation in one direction so that the nut member can move only in the closing direction of the door is provided. A bearing structure consisting of a roller that prevents rotation in one direction and inner and outer rings for this roller. By moving the outer ring in the axial direction, the drive shaft can be switched between the locked position and the unlocked position at an arbitrary position. It has been described.
[0005]
[Problems to be solved by the invention]
However, in the case of a belt-driven automatic door as described above, when the door hanging bracket connected to the belt reaches the door movement limit, the drive is stopped by a limit switch or the like and stopped until the next closing operation. When it is in a state or when a certain time has passed, it is driven in reverse in the closing direction. However, in such a configuration, there is a problem that the drive belt extends and malfunctions due to frequent operation.
[0006]
In addition, in the screw type automatic door known from the above-mentioned Japanese Patent No. 2647329, it is necessary to provide a ball screw shaft (drive shaft) and a separate locking device in parallel therewith, and a one-way clutch is assembled to the drive shaft. In addition, a complicated structure linked with the locking device is required. For this reason, it is unavoidable that the cost is inevitably increased because it is necessary to configure a large number of parts in combination. Moreover, there is a problem that requiring a large number of parts provides a cause of failure accordingly.
[0007]
The present invention has been made in view of such a situation, and when a screw having a large lead is used and a drive function incorporated in the shaft core is used to exceed a specific condition, the drive function by the screw is achieved. It aims at providing the screw actuator provided with the function which can be stopped automatically.
[0008]
[Means for solving the problems and actions / effects]
In order to solve such a problem, the screw actuator according to the present invention is a first invention,
A drive shaft that is rotationally driven by a drive machine, a screw with a large lead that is fitted on the drive shaft and is rotationally driven and supported so as to be movable in the axial direction, and one end fixed to the drive shaft. Two sets of elastic bodies that apply thrust to both sides of the screw in an equilibrium state so that the ends are in contact with the screw side, and propulsion movement guided in parallel with the screw axis in contact with the groove of the screw And a moving body having a plurality of guide rollers.
[0009]
According to the present invention, a screw having a large lead is supported on a drive shaft that is rotationally driven by a drive machine, and the moving body is moved in the axial direction via the guide roller that engages the screw groove by the rotation of the screw. If the acting force in the moving direction (axial direction) becomes excessive when the moving body is guided by the screw, the screw is made slidable on the drive shaft, so that the equilibrium state is maintained. By moving against the thrust of one of the slacking elastic bodies, it is possible to buffer the overload and prevent the straight movement by the screw from becoming unreasonable. In addition, even if a thrust is applied to the screw due to overload, elastic bodies are arranged at both ends of the screw so that they are balanced, so when the load force is released, the screw is quickly returned to the steady position. Can be restored. Therefore, when the moving body is operated by rotating the screw forward and backward, the screw can be easily returned during the reverse rotation operation. In addition, since the screw itself can decelerate without using a deceleration drive machine, a speed setting drive machine is preferable.
[0010]
In the first invention, the drive shaft may have a configuration in which an intermediate portion is formed in a square cross section, and a screw is slidably fitted on the cross section square shaft portion (second invention). By doing so, the screw is driven to rotate by the drive shaft, and an effect is obtained that it is easy to slide in the axial direction by a load acting from the moving body side to which the guide roller guided by the screw is attached.
[0011]
In the first or second aspect of the invention, the screw is partially formed with an enlarged diameter at both ends thereof, and one end is abutted on the inner end and the other end is held on the drive shaft side. It is preferable that the coil springs are respectively arranged, the screws are balanced on the drive shaft by the coil springs, and can be moved to the opposite load side when an axial overload acts on the screw (third invention). ).
[0012]
According to such a third invention, the screw is supported on the drive shaft so as to be rotatable and slidable in the axial direction, and is kept balanced by the coil springs from both sides thereof. By arranging so as to be located inside, there is no problem in the operation of guiding and moving a plurality of guide rollers provided on the moving body side. Even if the screw slides in the axial direction due to overload, it can be returned to the equilibrium state (normal state) by the stored energy of the compressed coil spring.
[0013]
Further, in the first invention or the third invention, both ends of the screw are provided with screw slide detecting portions having a groove trough diameter of the screw or a diameter smaller than that, and on the structure side supporting the screw, Sensors for detecting sliding of the screw are provided, and when the sensor detects that the screw has been slid, the drive is stopped, and the stopping operation by the sensor is performed by the restoring force of the coil spring compressed at this time. It is good to be a structure linked | related with a control part so that it may cancel | release (4th invention).
[0014]
According to the fourth aspect of the present invention, when the screw is moved in the axial direction during operation, the sensor detects that the screw slide detection unit located at either one of the two ends has moved. It is possible to stop the rotation, stop the operation due to the overload associated with the movement of the moving body by the screw, and prevent the occurrence of a failure. When the load is removed or reversely operated, the compression-side coil spring pushes back the screw with the compression accumulating force, and the stop signal from the stop detection sensor is released, so that normal operation can be performed. .
[0015]
In the first invention, an encoder may be associated with the drive shaft so that the moving amount of the moving body by the screw can be controlled (fifth invention). In this way, the movement distance of the moving body moved through the guide roller can be calculated by electrically reading the rotation speed of the drive shaft and multiplying the rotation speed by the lead length of the screw. There is an advantage that it can be easily controlled.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific embodiment of the screw actuator according to the present invention will be described with reference to the drawings. In this embodiment, an automatic door opening and closing device will be described.
[0017]
FIG. 1 is a front view showing an automatic door opening and closing device of the present embodiment, and FIG. 2 is a longitudinal sectional view (a) of a screw operating device in the automatic door and a sectional view (a) taken along line aa. FIG. 3 shows a cross-sectional view of the main part of the sliding guide for the sliding door within the blind.
[0018]
The automatic door opening and closing device 1 of this embodiment is provided with an invisible 2 of a required length above an opening of a structure (for example, an entrance of a building, a vehicle, etc.), and is supported by a base frame 3 inside thereof. A speed setting drive 4, a drive shaft 6 connected to the output shaft 4 a of the speed setting drive 4 and supported by bearings 5 and 5 that attach both ends to the frames 3 a and 3 b, A screw 7 supported by a coaxial core and rotated while being axially slidable, buffer springs 14 and 14 for maintaining the screw 7 in an equilibrium state on the drive shaft 6, and a slide of the screw 7 It comprises a detection mechanism for detection and door guide means for guiding the sliding door (door 30) in parallel with the axis of the drive shaft 6 (screw 7).
[0019]
One end of the drive shaft 6 is directly connected to the output shaft 4a of the speed setting drive machine 4 by a joint 4b, and the end and the other end thereof are supported by bearings 5 and 5 provided on the frames 3a and 3b. Both end portions are round shafts 6b and 6b having a required length, and the intermediate portion is a shaft body 6a having a regular hexagonal cross section between both round shafts 6b and 6b.
[0020]
The screw 7 that is fitted to the drive shaft 6 and is given a rotational force is provided with a rectangular spiral groove 7a having a required outer diameter and a relatively large lead, and the shaft core has six screw shafts 6a. A sleeve 8 having a hexagonal hole 8a that is slidably fitted to a rectangular intermediate shaft body 6a is incorporated. The screw 7 has a sleeve 8 (made of metal) and is formed of a synthetic resin having high mechanical strength, or is made of steel.
[0021]
Further, stepped holes 7b and 7b having an inner diameter larger than the diameter of the sleeve 8 are formed at both ends of the screw 7, so that the coiled spring 14 can be housed in each of the stepped holes 7b. The coil spring casings 9 and 9 are fitted symmetrically. Note that a part of the coil spring casing 9 protrudes from the end of the screw 7 to the outside by a required length so that the outer peripheral surface of the protruding portion becomes the reversing sensor detector 10.
[0022]
Inside the coil spring casings 9, 9 fitted and attached to both ends of the screw 7, the coil spring 14 is externally mounted on the drive shaft 6 and cannot be removed by the retaining ring 13. Between the flange piece 12 and the inner end portion of the coil spring casing 9, a coil spring 14 is loosely fitted on the drive shaft 6 in an accumulated state, and the screw 7 is pressed in the axial direction from the front and rear. As a result, the equilibrium state is maintained.
[0023]
Further, on the speed setting drive unit 4 side of the drive shaft 6 that supports the screw 7, there is a disk 16 (see FIGS. 1 and 3) having a large number of small windows 16 a drilled at a required pitch in the circumferential direction. An encoder 15 is provided that is attached to a bracket 19 that is supported by the base frame 3 so that the light projecting / receiving device 17 straddling the disc 16 so as to face the forming portions of the small windows 16a. Yes. Further, the base frame 3 is reversed to a position slightly apart from the end surfaces of the reversing sensor detection bodies 10 and 10 attached to the end of the screw 7 that is kept in equilibrium by the front and rear coil springs 14 and 14 described above. Each of the sensors 18 is attached, and these inversion sensors 18 are electrically connected to a separately installed controller 20. The reversing sensor 18 and the reversing sensor detector 10 constitute a detection mechanism that detects the sliding of the screw 7.
[0024]
Although not shown in the figure, the controller 20 receives a command signal for normal rotation or reverse rotation of the speed setting drive machine 4 to rotate the screw 7 forward via the drive shaft 6, and the door 30 is closed. When the slide detection mechanism in which the reverse sensor 18 detects the movement of the reverse sensor detector 10 is activated, the screw 7 is controlled to stop or reverse, and the rotation speed is detected by the encoder 15. In the calculation unit, a program preset to detect the movement distance of the door 30 and control the movement amount is incorporated in the calculation unit.
[0025]
With respect to the operating mechanism of the screw 7 having such a configuration, the door 30 side is provided with a hanging metal fitting 23 so that the door wheel 22 is guided to a guide rail 21 provided integrally with the base frame 3 inside the mesh 2. Is attached to the upper part of the door 30. The power transmission roller 25 that engages with the spiral groove 7 a of the screw 7 is disposed on the upper portion of the door 30 at an integral multiple pitch of the lead of the spiral groove 7 a of the screw 7. The guide rail 21 and the axis of the screw 7 are arranged so as to be parallel to each other, and the bracket is attached to the upper portion of the door 30 guided by the guide rail 21 via the door wheel 21 and the hanging bracket 23. The rotation axis of the power transmission roller 25 supported by the screw 24 and engaged with the helical groove 7 a of the screw 7 is related so as to substantially coincide with a vertical plane passing through the axis of the screw 7.
[0026]
The power transmission roller 25 operated by the rotation of the screw 7 has an elastic material 26 integrally attached to the roller outer peripheral portion 25a as shown in FIGS. 4 (a) and 4 (b), for example. It is preferable to use The elastic material 26 is preferably a material with high wear resistance such as urethane rubber. By using the power transmission roller 25 including the elastic member 26 on the outer peripheral portion 25a, it is possible to reliably transmit power and prevent environmental problems such as generation of noise. The roller body 25b is formed with a groove 25c having a concave curved surface in the outer peripheral portion to which the elastic material 26 is integrally attached, and the elastic material 26 attached to the groove 25c is reliably maintained in a fixed state. Has been made. The power transmission roller 25 is provided with a rolling bearing inside and is rotatably supported by a support shaft 27 attached to the top top of the door 30 in an upright state. Further, the power transmission roller 25 is brought into contact with one side surface of the spiral groove 7a of the screw 7 in a direction orthogonal to each other so that the propulsive force generated by the rotation of the screw 7 is reliably transmitted.
[0027]
In the automatic door opening and closing device 1 configured as described above, the door opening signal is transmitted from the controller 20 in the closed state, the speed setting drive unit 4 is operated in reverse, and the screw 7 is connected via the directly connected drive shaft 6. Reverse. Then, the power transmission roller 25 that engages with the spiral groove 7a of the screw 7 is moved in the direction opposite to that when the door is closed. As a result, the plurality of power transmission rollers 25 are sequentially moved by the screw 7 and the door 30 is moved in the opening direction. At this time, the door 30 is moved by the suspension fitting 23 attached to the upper portion thereof, with the door wheel 22 attached to the suspension fitting 23 being guided by the guide rail 21 within the eye 2 and opened.
[0028]
In this opening operation, if the screw 7 rotates excessively and an overload is applied to the screw 7 in an attempt to send the power transmission roller 25 to a predetermined position or more, the coil spring 14 is applied to the screw 7 from both the front and rear directions in the axial direction. , 14, the balance is lost due to the load, and the screw 7 is slid to one side by the shaft body 6a portion of the drive shaft 6 while rotating.
[0029]
Then, the reverse sensor detection body 10 attached to the end of the screw 7 is detected by the reverse sensor 18 attached to the base frame 3, and the rotational drive of the speed setting drive machine 4 is stopped. As a result, the movement of the door 30 to which the power transmission roller 25 is attached is automatically stopped. Therefore, the speed setting drive unit 4 is not burned due to an overload.
[0030]
When the rotation of the screw 7 is stopped, the coil spring 14 on the side which is arranged at both ends of the screw 7 and loses its balance and is compressed to one side pushes the screw 7 back to its original equilibrium state by the stored energy. It is.
[0031]
Therefore, when a door closing operation signal is next input to the controller 20, the speed setting drive unit 4 is immediately driven in the forward rotation direction by the operation signal from the controller 20 and is directly connected to the output shaft 4a. The forward rotation of the screw 7 also causes the screw 7 to rotate forward, and the power transmission roller 25 engaged by the spiral groove 7a is sequentially moved toward the closing door, and the door 30 is closed. When the door 30 is closed, for example, if the door 30 is of a single-open type, if the movement of the door 30 is stopped by the door stopper, the rotation of the screw 7 is overloaded unless it stops accordingly. The screw 7 slides on the drive shaft 6 in the opposite direction, and the reversing sensor 18 at the position issues a detection signal, and the speed setting drive machine 4 is stopped. Of course, when the screw 7 is stopped, the screw 7 is pushed back to a fixed position by the repulsive force of the coil spring 14 compressed by the roller from which the acting overload is removed, so that the next operation can be handled.
[0032]
When the door 30 is opened and closed in this manner, the door 30 is moved lightly by being guided along the guide rail 21 provided integrally with the base frame 3 by the door wheel 22 attached to the hanging bracket 23. can do. Moreover, since the guide surface of the helical groove 7a of the screw 7 is orthogonal to the axis, the propulsive force to the power transmission roller 25 to be engaged can be transmitted efficiently. Further, the power transmission roller 25 can be operated silently by forming the outer peripheral portion 25a thereof by the elastic body 26, thereby reducing the occurrence of slip between them and simultaneously eliminating the generation of noise during operation. It can be done.
[0033]
In the opening / closing device 1 for performing the opening / closing operation in this way, a disk in which a number of small window portions 16a attached to the drive shaft 6 are arranged at equal pitches simultaneously with the rotation of the screw 7 (drive shaft 6). Since the rotation speed is constantly detected by the encoder 15 that detects the rotation of the light 16 by the light projector / receiver 17, the movement distance of the door 30 can be calculated and detected by the controller 20 via the power transmission roller 25 by the screw 7. In addition, the amount of movement of the door 30 can be easily controlled.
[0034]
As described above, in the present embodiment, a compact structure can be used to restrict excessive movement, or a drive unit due to overload, in other words, the opening / closing device 1 can be protected and operated without overwork. is there. Further, in the present embodiment, since the lead of the screw 7 is large, it is easy to manually open and close the door 30 when the power is turned off (when a power failure occurs). Therefore, it is more effective than a conventional automatic door opening and closing device.
[0035]
In the above description, the embodiment has been described as an automatic door opening and closing device. However, in addition to this, for example, an operating mechanism is disposed on the lower side of the conveyor line, and a carrier having a power transmission roller facing downward is provided along the guide rail. If it is moved, it can be used as a drive means for the conveyor line. In that case, not only as a reversing operation by the reversing sensors 18 and 18 to the balancing means by the coil springs 14 and 14 and the reversing sensor detectors 10 and 10. After the operation is stopped due to overload, the operation can be returned to normal operation by temporarily performing reverse rotation. In addition, as the drive machine, a reduction drive machine can be adopted as necessary.
[0036]
ADVANTAGE OF THE INVENTION According to this invention, it can utilize effectively as a drive device provided with the buffer function which moves a to-be-moved body along a guide rail by driving a screw.
[Brief description of the drawings]
FIG. 1 is a front view showing an automatic door opening and closing device according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view (a) and a sectional view (b) taken along the line aa of the screw operating device.
FIG. 3 is a cross-sectional view of a principal part of a sliding guide for a sliding door within a seamless area.
FIG. 4 is a partial sectional detail view (a) showing a relationship between a screw and a power transmission roller, and a longitudinal sectional view (b) of the power transmission roller.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Opening and closing device 2 Base 3 Base frame 4 Speed setting drive machine 6 Drive shaft 6a Drive shaft body 7 Screw 7a Spiral groove 8 Sleeve 9 Coil spring casing 10 Reverse sensor detection body 14 Coil spring 15 Encoder 18 Reverse sensor 20 Controller 21 Guide rail 22 Door wheel 23 Suspension bracket 25 Power transmission roller 26 Elastic material 30 Door

Claims (5)

A drive shaft that is rotationally driven by a drive machine, a screw with a large lead that is fitted on the drive shaft and is rotationally driven and supported so as to be movable in the axial direction, and one end fixed to the drive shaft. Two sets of elastic bodies that apply thrust to both sides of the screw in an equilibrium state so that the ends are in contact with the screw side, and propulsion movement guided in parallel with the screw axis in contact with the groove of the screw And a moving body including a plurality of guide rollers. 2. The screw operating device according to claim 1, wherein the drive shaft is configured such that an intermediate portion is formed in a square cross section, and a screw is slidably fitted on the cross section square shaft portion. Each of the screws is formed with an enlarged diameter at both ends thereof, and coil springs are arranged with one end abutting on the inner end and held at the other end on the drive shaft side. The screw operating device according to claim 1 or 2, wherein the screw is balanced on the drive shaft and is movable to the opposite load side when an axial overload acts on the screw. Both ends of the screw are provided with a screw slide detecting section having a groove trough diameter of the screw or a diameter smaller than that, and sensors for detecting the sliding of the screw are arranged on the side of the structure supporting the screw. When the sensor detects that the screw has been slid, the drive unit is stopped, and the stopping operation by the sensor is released by the restoring force of the coil spring compressed at this time. Item 4. The screw actuator according to Item 1 or 3. The screw operating device according to claim 1, wherein an encoder is associated with the drive shaft to control a moving amount of the moving body by a screw.

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