JP3123286U - Lift actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lift actuator having a compact structure for transmitting a power of a motor to an output rod side without using a special mechanism member and generating a large pressing force on the output rod.
Power of a motor 2 is transmitted to a screw shaft 5 via a reduction gear 3 having a large reduction ratio. For example, a guide plate 8 that holds a nut piece 6 that is screwed to the screw shaft 5 is provided in an axial direction of the screw shaft. And the output rod engaged with the inclined groove 8b formed in the guide plate 8 is moved to generate a pressing force. By devising the reduction ratio of each component and the thrust force and friction force generated in the drive system, the bearing mechanism 13 can be greatly reduced to generate a large pressing force.
[Selection] Figure 1

Description

  The present invention relates to a compact lift actuator that generates an extremely large pressing force, and reduces the thrust force and frictional force generated in the drive system path without using a special mechanism to enable efficient force transmission. The present invention relates to a lift actuator that generates pressure.

There are various types of lift actuators, for example, an actuator described in “Patent Document 1”. This device uses magnetic force as shown in FIG. 1, and is different from the present invention in configuration. On the other hand, although there is no known document, there is an attempt to transmit this power to the output rod using a screw mechanism or the like using a motor with a speed reducer. There is a problem that the power on the motor side is not effectively transmitted to the output rod side due to the thrust force and frictional force in the case, and only one third or less of the desired pressing force can be obtained.
Japanese Patent Laying-Open No. 2005-330942 (FIG. 1)

  As described above, the conventional technology does not have a technique for transmitting a large pressing force to the output rod side using a motor. To give a desired pressing force to the output rod side, an extremely powerful motor is used and There is a problem that it is necessary to use an expensive bearing or a bearing holding mechanism in the drive system path, and the processing accuracy of the apparatus is high and expensive.

  The present invention has been devised in view of the above circumstances, and a lift actuator that generates a desired extremely large pressing force on the output rod side that is compact as a whole without acting on a special mechanism portion. The purpose is to provide.

  In order to achieve the above object, the present invention provides a motor with a reduction gear, a screw connected to the motor, and a screw feed by the motor or the like while moving in a direction perpendicular to the screw shaft. A lift actuator including an output rod that generates a large pressing force, wherein a bearing mechanism portion that reduces thrust force and frictional force is disposed in a drive system path of the actuator.

  According to a second aspect of the present invention, the motor with the speed reducer is fixed to a base plate via a motor holder, and a nut piece that is screwed onto the screw shaft in a rod holding portion that movably supports the output rod. And a guide plate constituting a straight groove and an inclined groove in a direction inclined with respect to the screw axis direction and a direction inclined thereto are supported so as to be movable along the screw axis direction. A thrust bearing provided between the screw shaft and the motor holder to reduce a thrust force of the screw shaft; a bearing provided between the output rod and the inclined groove; the rod holding portion; and the guide. It consists of a bearing provided between the straight grooves of the plate.

  Further, in the invention of claim 3, the motor with the speed reducer is fixed to a base plate, and the motor with the speed reducer is connected to a screw shaft arranged in a horizontal direction perpendicular to the output rod, A feed piece having a nut portion screwed to a screw shaft is fixed to a push rod arranged in parallel with the screw shaft, and a rotating arm is pivotally supported by a rod holding portion that movably supports the output rod, The rotating arm is formed with an abutting portion where the tip end of the push rod abuts and engages, and an arm portion connecting the tip portion to the output rod, and the screw shaft has a motor with a speed reducer at the tip side. Thrust support is provided by a thrust bearing fixed to the side.

  According to a fourth aspect of the present invention, a pair of limit switches for controlling the amount of movement of the guide plate or push rod and the amount of movement of the output rod related thereto can be adjusted on the base plate. It is provided.

  The invention of claim 5 is characterized in that the amount of movement of the guide plate or push rod is at least three times the amount of movement of the output rod.

  The invention according to claim 6 is characterized in that the nut piece is held by the nut piece holder through a gap.

  According to the lift actuator of claim 1 of the present invention, the power of the motor with the speed reducer is of a simple structure that is transmitted to the output rod side via the screw shaft. A bearing mechanism that reduces the generated thrust force and frictional force as much as possible is provided, so that the driving force from the motor side is smoothly transmitted to the output rod side, resulting in the generation of a desired large pressing force. Can do.

  According to the lift actuator of claim 2 of the present invention, the power on the motor side can be moved to the rod holding portion that holds the guide plate movably by moving the guide plate holding the nut piece via the screw shaft. It is transmitted to the held output rod. In this case, the thrust force of the screw shaft is reduced by the thrust bearing, and the guide plate and the output rod move through the bearing, so that the frictional force can be greatly reduced. In addition, an inclined groove is formed in the output plate, which is transmitted to the output rod side in a state in which the amount of movement of the guide plate is reduced, and a reduction ratio is generated here, so that a large force can be transmitted.

  According to the lift actuator of claim 3 of the present invention, the feed piece and the push rod are moved through the screw shaft by the rotation of the motor with the speed reducer, and the output rod is moved by rotating the rotary arm. Therefore, the structure is simpler than that of the second aspect, and the structure is compact and can be implemented at low cost.

  According to the lift actuator of claim 4 of the present invention, as described above, the amount of movement of the guide plate or push rod is greatly reduced and transmitted to the output rod. In this case, the guide plate or push rod And the output rod are adjusted by a pair of limit switches. Thereby, a desired reduction gear ratio can be produced.

  According to the lift actuator of claim 5 of the present invention, a desired pressing force can be obtained by making the movement ratio between the guide plate or the push rod and the output rod three times or more.

  According to the lift actuator of claim 6 of the present invention, since the nut piece screwed to the screw shaft is supported by the nut piece holder via the gap, even if the screw shaft has a low screw accuracy or its assembly accuracy. The transmission force of the screw shaft is smoothly transmitted to the nut piece, and no “seri” or the like occurs between the two. As a result, the transmission efficiency of force can be improved.

  Hereinafter, an embodiment of an actuator of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1A and 1B, the lift actuator 100 is roughly divided into a base plate 1, a DC motor 2 having a speed reducer 3 fixed to a motor holder 4 fixed to the base plate 1, and a DC motor 2. A screw shaft 5 connected to the motor shaft (not shown), a nut piece holder 7 for holding a nut piece 6 to which a screw 5a of the screw shaft 5 is screwed, and a guide plate for fixing the nut piece holder 7 to one end side. A rod holding portion 9 comprising a holding portion 9a fixed to the base plate 1 and a holding portion 9b formed integrally therewith and sandwiched between the pair of guide plates 8 and 8; A pair of output rods 10 slidably held in guide holes 11 drilled along a direction orthogonal to the screw shaft 5 and a base plate 1 movably supported along the direction of the screw shaft 5. Limit sensors 12, 12 and Consisting of a bearing mechanism section 13 and the like to be described later.

  As shown in FIG. 1A, the base plate 1 is made of a relatively thick plate material, and as shown in FIG. 1B, the base plate 1 is made up of a rectangular portion 1a and a tapered portion 1b that is reduced in size toward the tip side. What forms the taper part 1b is for weight reduction.

  The motor holder 4 is composed of a block having a U-shaped cross section, and its upper end surface is fixed to the base plate 1. A DC motor 2 having a speed reducer 3 is fixed to one side surface of the motor holder 4. As shown in FIGS. 1 and 2, a screw shaft 5 having an enlarged thrust portion 5 b is connected to the drive shaft 3 a from the speed reducer 3. A thrust bearing holding mechanism 14 for holding a thrust bearing 13a described later is fixed in the U-shaped concave groove 4a of the motor holder 4.

As shown in FIGS. 3 (a) and 3 (b), the nut piece holder 7 is integrally formed with the square plate portion 7 a so as to protrude to the top and is formed of an engaging piece 7 b and is fixed to the side surface of the guide plate 8. It consists of a block body. A ground-shaped concave portion 7 c is formed on the screw plate 5 side of the guide plate 8.
On the other hand, the recess 7c accommodates a nut piece 6 having an approximate shape with the recess 7c. A minute gap 15 is formed between the outer surface of the nut piece 6 and the inner surface of the recess 7c, and the nut piece 6 can freely move within the recess 7c by the amount of the minute gap 15. The nut 5 is screwed with the screw 5a of the screw shaft 5.

  4 (a) and 4 (b), the rod holding portion 9 is fixed to the base plate 1, and the holding portion 9a fixed to the base plate 1 as shown in FIGS. 4 (a) and 4 (b). It consists of what forms the clamping part 9b formed by reducing in size below this. As shown in FIGS. 4A and 4B, a guide hole 11 is drilled in the center of the rod holding portion 9, and a bearing 13b as a guide bearing of a bearing mechanism portion 13 to be described later is provided in the clamping portion 9b. 13b, 13b, and 13b are connected so that rotation is possible.

  The guide plate 8 is formed of a plate-like plate as shown in FIGS. 1 and 5, and can slide in a state where the holding portion 9b of the rod holding portion 9 is held as shown in FIGS. Retained. The pair of guide plates 8, 8 are connected by screws 16 as shown in FIG. As shown in FIG. 5, a straight groove 8 a and an inclined groove 8 b formed in a direction parallel to the screw shaft 5 are recessed on the inner surface side of the guide plate 8.

  As shown in FIGS. 1 and 6, the output rod 10 is composed of a rod-shaped member disposed in a direction orthogonal to the screw shaft 5, and is supported in a guide hole 11 of the rod holding portion 9 so as to freely enter and exit. Is disposed so as to protrude through the base plate 1. The output rod 10 finally generates a pressing force and has a strength that can withstand the pressing force. Further, as shown in FIG. 6, bearings 13 c and 13 c as gradient rollers of the bearing mechanism portion 13 are rotatably connected to the lower end side of the output rod 10, and the bearings 13 c and 13 c are inclined grooves of the guide plate 8. Engage with 8b. Further, a guide pin 17 squeezed and formed at an intermediate portion of the output rod 10 is arranged perpendicular to the axial direction of the output rod 10. The guide pin 17 engages with a guide groove 9c formed in the holding portion 9a of the rod holding portion 9 as shown in FIGS. 4 (a) and 4 (b).

  FIG. 6 is a sectional view in which the guide plate 8, the rod holding portion 9, the output rod 10, and the like are combined, and the engagement state and the attachment state of these components are clearly shown.

  As shown in FIGS. 1A and 1B, the limit sensor 12 is composed of a pair of limit sensors 12a and 12b. As shown in the drawing, a screw 18 is provided below the base plate 1 along the axial direction of the screw shaft 5. Fixed to be movable. A lead wire 19 is connected to the limit sensors 12a and 12b, and the lead wire 19 is connected to a power supply unit (not shown). The limit sensors 12a and 12b generate a detection signal only when the engagement piece 7b of the nut piece holder 7 is engaged. The distance between the pair of limit sensors 12a and 12b is the moving distance of the guide plate 8. The output rod 10 moves through the bearing 13c engaged with the inclined surface 8b by the movement of the guide plate 8. The amount of movement of the output rod 10 is determined by the inclination angle of the inclined groove 8b and the amount of movement of the guide plate 8. In this embodiment, the movement ratio of both is 1: 3, and the transmission force is 1/3. Although improvement is intended, of course, it is not limited to this.

  Next, the bearing mechanism part 13 will be described. The bearing mechanism 13 includes a thrust bearing 13a, a guide roller bearing 13b, a gradient roller bearing 13c, and the like, as shown in FIGS. As shown in FIG. 2, a thrust bearing 13a is attached to the drive shaft 3a. The thrust bearing 13a is held at a predetermined position by a thrust bearing holding member 14, and a thrust portion of the screw shaft 5 is provided on the thrust surface of the thrust bearing 13a. 5b contacts. The thrust bearing 13a is sandwiched between the side surface of the motor holder 4 and the thrust bearing holding member 14, but is assembled so that a slight gap (backlash) remains in the thrust direction.

Next, a process of generating a pressing force from the output rod 10 by the lift actuator 100 of the present invention will be described. In this embodiment, the speed reduction ratio of the speed reducer 3 is 1/100, but the present invention is not limited to this. The rotation of the motor 2 is transmitted to the drive shaft 3 a via the speed reducer 3, and a high torque rotational force is transmitted to the screw shaft 5. As the screw shaft 5 rotates, the nut piece holder 7 moves in the direction of the screw shaft 5 through the nut piece 6 screwed into the nut, and accordingly, the guide plate 8 moves in the screw shaft direction. By the movement of the guide plate 8, the output rod 10 is moved by the inclined groove 8b, and a pressing force is applied to the pressing force transmitting portion (not shown) that is in contact with the apex. As described above, the amount of movement of the guide plate 8 is performed by adjusting the limit sensor 12.
Due to the above drive system path, the power of the DC motor 2 generates a large pressing force depending on the ratio of the speed reducer 3, the guide plate 8 and the inclination angle of the inclined groove 8b. However, the bearing mechanism 13 and the screw shaft 5 and the nut piece 6 Without the device of the present invention for the threaded portion, the thrust force and friction force are not absorbed during movement, and the theoretical pressing force does not occur.

  In the present invention, first, the thrust force generated by the screw feed of the screw shaft 5 is absorbed by the thrust bearing 13a and becomes a very small value due to the minute gap in the thrust direction of the thrust bearing 13a. Even if the screw engagement of the screw shaft 5 by the screw 5a and the nut piece 6 is harmonized, the nut piece 6 is held by the nut piece holder 7 through the fine gap 15 so that the screw engagement can be achieved. Loss force due to incongruity does not occur. Further, the movement of the guide plate 8 in the direction of the screw shaft 5 is almost zero because the friction force is absorbed because the bearing 13b rolls along the straight groove 8a. Moreover, the frictional force in the case of moving along the inclined groove 13c by the bearing 13c of the output rod 10 is absorbed and becomes almost zero. As described above, in the lift actuator 100 of the present invention, the driving force from the motor 2 is transmitted to the output rod 10 with almost no loss, and a large pressing force can be generated. In addition, according to the lift actuator 100 of the present Example, it was proved that the pressing force of 150 kg or more was generated.

  In the first embodiment, the straight groove 8a and the inclined groove 8b of the guide plate 8 are used as a mechanism for moving the output rod up and down. However, the second embodiment uses a rotating arm having a compact structure instead of these. The rotation is transmitted to the output rod to move the output rod up and down, and is simpler and more compact than the first embodiment. Therefore, it can be implemented at low cost.

Hereinafter, although the schematic structure of the lift actuator of Example 2 is shown in FIG. 7, the description which overlaps with an Example is abbreviate | omitted.
As shown in FIG. 7, a screw shaft 50 is connected to a speed reducer 3 of a motor (DC motors) with a speed reducer fixed to the base plate 1, and the screw shaft 50 is fixed to the speed reducer 3 side. Thrust force applied to the screw shaft 50 is reduced by a thrust bearing 13a which is one of the parts. The screw shaft 50 is provided with a feed piece 20 having a nut portion 20a screwed to the screw shaft 50, and the feed piece 20 is fixed to the push rod 21. In addition, the front end side of the nut portion 20a of the feed piece 20 is formed to be engaged with the limit switches 12a and 12b. Further, the push rod 21 is arranged in parallel with the screw shaft 50.

The output rod 10 is supported by a rod holding portion 90 fixed to the base plate 1 so as to be movable up and down. Further, the pivot arm 22 is pin-supported by the rod holding portion 90 so as to be pivotable. The rotating arm 22 is formed of a lever arm-like member having an abutting portion 22a at one end and an arm portion 22b at the other end.
The abutting portion 22 a is disposed at a position where it can abut and engage with the tip of the push rod 21, and the arm portion 22 b connects the tip of the output rod 10. In addition, although it is desirable to reduce the mechanical loss by using a bearing (not shown) for the connecting portion between the contact portion 22a and the arm portion 22b with the output rod 10, it is not limited to this.

With the above structure, the screw shaft 50 is rotated by driving the DC motor 2, whereby the feed shaft 20 and the push rod 21 are moved. This amount of movement is arbitrarily adjusted by adjusting the positions of the limit sensors 12a and 12b.
The movement of the push rod 21 is transmitted to the rotating arm 22 through the contact portion 22a, and the rotating arm 22 rotates with the support point of the rod holding portion 90 as a base point. By this rotation, the arm portion 22b is rotated, and the output rod 10 connected to the arm portion 22b is moved up and down.
The amount of movement of the output rod 10 is controlled by the amount of movement of the push rod 21 as described above. For example, the same effect as in the first embodiment can be achieved by controlling the movement ratio.

  Examples of the intermediate mechanism for moving the output rod 10 up and down by the DC motor 2 include those in the first embodiment and the second embodiment, but of course, the invention is not limited to these, and a known technique in the same technical category is applied. Of course.

  The present invention relates to a lift actuator that generates a large pressing force as described above. However, any object requiring this pressing force may be used, and its range of use is extremely wide.

The side view (a) which shows the whole structure of the lift actuator of this invention, and its top view (b). The fragmentary sectional view which shows the reduction structure of the thrust force of a screw shaft. The perspective view (a) which shows the structure around a nut piece holder, The fragmentary sectional view (b) which shows the screwing state of a nut piece and a screw shaft. The perspective view (a) which shows the structure of a rod holding part, and the AA sectional view (b) of Drawing 1 (a). The perspective view which shows the structure of a guide plate. Sectional drawing which shows the assembly | attachment state of a rod holding | maintenance part, a guide plate, and an output rod. The side view which shows the whole structure of the lift actuator by the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base plate 1a Rectangular shape part 1b Tapered part 2 DC motor 3 Reduction gear 3a Drive shaft 4 Motor holder 4a Groove 5 Screw shaft 5a Screw 5b Thrust part 6 Nut piece 7 Nut piece holder 7a Square plate part 7b Engagement piece 7c Recessed part 8 Guide plate 8a Straight groove 8b Inclined groove 9 Rod holding portion 9a Holding portion 9b Holding portion 9c Guide groove 10 Output rod 11 Guide hole 12 Limit sensor 12a Limit sensor 12b Limit sensor 13 Bearing mechanism portion 13a Thrust bearing 13b Bearing (guide roller)
13c Bearing (gradient roller)
14 Thrust bearing holding member 15 Small gap 16 Screw 17 Guide pin 18 Screw 19 Lead wire 20 Feeding piece 20a Sensor engaging portion 21 Push rod 22 Rotating shaft arm 22a Abutting portion 22b Arm portion 50 Screw shaft 90 Rod holding portion 100 Lift Actuator 100a Lift actuator

Claims (6)

  A lift actuator comprising: a motor with a speed reducer; a screw connected to the motor; and an output rod that generates a large pressing force while moving in a direction perpendicular to the screw shaft by screw feed by the motor or the like. A lift actuator characterized in that a drive mechanism is provided with a bearing mechanism for reducing thrust force and frictional force.   The motor with a speed reducer is fixed to a base plate via a motor holder, and a nut piece holder for holding a nut piece screwed to the screw shaft is fixed to a rod holding portion that movably supports the output rod. In addition, the guide plate constituting the straight groove and the inclined groove is supported so as to be movable along the screw shaft direction in the screw shaft direction and the direction inclined thereto, and the bearing mechanism portion reduces the thrust force of the screw shaft. For this purpose, a thrust bearing provided between the screw shaft and the motor holder, a bearing provided between the output rod and the inclined groove, and a rod holding portion and a straight groove of the guide plate are provided. The lift actuator according to claim 1, wherein the lift actuator is a bearing.   The motor with a speed reducer is fixed to a base plate, and a screw shaft arranged in a horizontal direction perpendicular to the output rod is connected to the motor with the speed reducer, and a nut portion screwed to the screw shaft is provided. The feed piece is fixed to a push rod arranged in parallel with the screw shaft, and a pivot arm is pivotally supported by a rod holding portion that movably supports the output rod, and the push rod is supported by the push rod. An abutting portion that abuts and engages with the output rod, and an arm portion that connects the leading end to the output rod, and the screw shaft is thrust by a thrust bearing that is fixed to the motor side with the speed reducer. A lift actuator that is supported.   The base plate is provided with a pair of limit switches for controlling the amount of movement of the guide plate or push rod and the amount of movement of the output rod associated therewith so that the amount of movement can be adjusted. The lift actuator according to 2 or 3.   The lift actuator according to claim 3, wherein the movement amount of the guide plate or the push rod is at least three times the movement amount of the output rod. The lift actuator according to claim 2, wherein the nut piece is held by the nut piece holder via a gap.

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