JP2021183360A - Gripping device and gripping system including the same - Google Patents

Abstract

To provide compact gripping device and gripping system, which facilitate a change in gear ratio and maintenance.SOLUTION: A gripping device includes: a drive section which generates rotation force; a speed reducer to which rotation force is transmitted; a body section into which the drive section and the speed reducer are stored; and a conversion section which is mounted in the body section and converts a rotary motion of the speed reducer to a linear motion. A first transmission shaft for transmitting rotation force from the drive section to the speed reducer and a second transmission shaft for transmitting rotation force from the speed reducer to the conversion section are arranged on the same axis. The speed reducer has a removable gear unit. The body section and the conversion section can be separated.SELECTED DRAWING: Figure 2

Description

The present invention relates to a gripping device for gripping a gripping object and a gripping system including the gripping device.

Conventionally, a gripping device that is attached to the tip of an arm of an industrial robot or the like to grip an object to be gripped (work) is known. Patent Document 1 discloses a gripping device that converts a rotary motion of a motor into a linear motion.

Japanese Unexamined Patent Publication No. 2002-292588

Conventional gripping devices can have different specifications such as gripping force and gripping speed by changing the gear ratio by combining multiple types of gears, but multiple types of gears and support shafts for gears. Peripheral parts such as are required, and the size increases. In addition, the number of parts will increase and the cost will increase.

Further, in a gripping device, generally, after amplifying the rotational force of a driving means such as a motor by a gear or the like, it is converted into a linear motion by a cam, a rack and a pinion, and the linear motion is held by a linear guide or the like. Each member is coated with grease to ensure wear resistance, etc., but maintenance is required because it will run out of oil if it is used continuously.

It is an object of the present invention to provide a compact gripping device and a gripping system including the same, in which the gear ratio can be easily changed and maintained.

The gripping device as one aspect of the present invention includes a drive unit that generates a rotational force, a speed reducer that transmits the rotational force, a drive unit, a housing unit in which the speed reducer is housed, and a housing. It has a conversion unit that is attached to the unit and converts the rotational movement of the reducer into linear motion, a first transmission shaft for transmitting the rotational force from the drive unit to the reducer, and the rotational force from the reducer. The second transmission shaft for transmitting the speed to the conversion unit is arranged on the same shaft, the speed reducer is provided with a removable gear unit, and the housing portion and the conversion unit are separable. And.

According to the present invention, it is possible to provide a compact gripping device and a gripping system including the same, in which the gear ratio can be easily changed and maintained.

It is a block diagram of the gripping system which concerns on embodiment of this invention. It is a block diagram of the gripping device. It is a block diagram of the rotation linear motion conversion mechanism part. It is an exploded perspective view of the housing part. It is explanatory drawing of assembly of a gripping device. It is sectional drawing which shows the state which changed the gear ratio of the gripping apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same member is given the same reference number, and duplicate description is omitted.

FIG. 1 is a block diagram of a gripping system 1000 according to an embodiment of the present invention. The gripping system 1000 includes a gripping device 1, a control device 2, and a power supply unit 4.

The control device 2 is a general-purpose computer or the like, and is connected to the gripping device 1 via a cable 3a. The control device 2 sends a signal to the gripping device 1, controls the gripping operation of the gripping device 1, receives a signal from the gripping device 1, and grasps the state of the gripping operation of the gripping device 1. The power supply unit 4 is connected to the gripping device 1 via the cable 3a and supplies electric power to the gripping device 1.

Inside the gripping device 1, an electric motor (drive unit) 10, an encoder 11 provided in the electric motor 10 and a controller (control unit) that controls the electric motor 10 by using signals of the encoder 11 and the encoder 11. 20 are arranged.

The controller 20 has a drive circuit 21 and a control circuit 22. The drive circuit 21 and the control circuit 22 are connected via a cable 3b. The drive circuit 21 is connected to the electric motor 10 via a cable 3c. The control circuit 22 is connected to the encoder 11 via the cable 3d.

Although the encoder 11 is provided in the electric motor 10 in the present embodiment, it may be provided in the gripping device 1 as a member separate from the electric motor 10. Further, instead of the encoder 11, a sensor or the like having the same role as the encoder 11 may be provided.

FIG. 2 is a configuration diagram of the gripping device 1. 2 (a) and 2 (b) are a side view and a sectional view taken along line AA of FIG. 2 (a), respectively.

The gripping device 1 has a rotation / linear motion conversion mechanism unit (conversion unit) 40, a gripping member 50, and a housing unit 60.

The housing portion 60 has a first housing 61 and a second housing 62. Further, the electric motor 10, the controller 20, and the speed reducer 30 are housed inside the housing portion 60.

The electric motor 10 generates a rotational force.

The controller 20 (drive circuit 21 and control circuit 22) is arranged at a position facing the axes of the electric motor 10 and the speed reducer 30. The control circuit 22 is provided with a connector 24 to which the cable 3a is connected. The connector 24 projects from the inside to the outside of the first housing 61 and the second housing 62, and is connected to the control device 2 and the power supply unit 4 via the cable 3a. The control circuit 22 rotates the electric motor 10 via the drive circuit 21 using the signal from the control device 2.

The speed reducer 30 is connected to the output shaft (first transmission shaft) 10a of the electric motor 10, and the rotational force is transmitted from the electric motor 10 via the output shaft 10a. The speed reducer 30 has a removable gear unit.

The rotation linear motion conversion mechanism unit 40 is attached to the housing unit 60 and converts the rotational motion of the speed reducer 30 into a linear motion. The rotation linear motion conversion mechanism unit 40 includes a rack 41, a pinion (second transmission shaft) 42, a linear guide 43, and a base member 44. The pinion 42 is arranged on the same axis as the output shaft 10a of the electric motor 10, and transmits the rotational force from the electric motor 10 to the rack 41 via the speed reducer 30. The rack 41 is attached to the grip member 50. The linear guide 43 is attached to the base member 44. The base member 44 is fixed to the first housing 61.

The gripping member 50 is attached to the rotation / linear motion conversion mechanism unit 40 to grip the object to be gripped. In this embodiment, the gripping member 50 is attached to the linear guide 43.

With the configuration described above, the rotary motion of the electric motor 10 is converted into a linear motion by the rack 41 and the pinion 42, and the gripping member 50 is guided by the linear guide 43, so that the gripping motion can be performed.

Hereinafter, a method of assembling the gripping device 1 will be described. FIG. 3 is a block diagram of the rotary linear motion conversion mechanism unit 40. 3 (a) to 3 (c) are a top view, an exploded perspective view, and a bottom view, respectively.

When assembling the rotary linear motion conversion mechanism unit 40, first, the first positioning pin 45 and the second positioning pin 46 are inserted and attached to the base member 44. Further, the linear guide 43 is attached to the opposite surface of the surface into which the first positioning pin 45 and the second positioning pin 46 of the base member 44 are inserted.

Next, the gripping member 50 is attached to the linear guide 43. Further, the third positioning pin 47 is inserted and attached to the rack 41 and the gripping member 50. The pinion 42, which is later inserted into the second positioning pin 46, and the rack 41, which is positioned by the third positioning pin 47, mesh with each other to enable gripping operation.

Finally, the cover 48 is attached to the base member 44. The cover 48 narrows the moving opening of the grip member 50 to prevent the grease and the like applied to the gears such as the rack 41 and the pinion 42 from scattering.

As described above, the rotation / linear motion conversion mechanism unit 40 is configured.

FIG. 4 is an exploded perspective view of the housing portion 60. When attaching the speed reducer 30 to the housing portion 60, first, the speed reducer 30 is inserted into the internal gear 60a provided in the first housing 61.

In this embodiment, the speed reducer 30 has a first gear unit 33a, a second gear unit 33b, and a third gear unit 33c. The first gear unit 33a has a planetary gear 34 that meshes with the internal gear 60a, and a first planetary carrier 35. The second gear unit 33b has a planetary gear 34 and a second planetary carrier 36 provided with a sun gear 36a that meshes with the planetary gear 34 of the first gear unit 33a. The third gear unit 33c is provided with a planetary gear 34 that meshes with the gear 37 attached to the output shaft 10a of the electric motor 10 and a sun gear 36a that meshes with the planetary gear 34 of the second gear unit 33b. Has a planetary carrier 36 of.

Next, the electric motor 10 is attached to the first housing 61. As a result, the rotational force of the electric motor 10 is decelerated and transmitted to the first planetary carrier 35. Subsequently, the drive circuit 21 and the control circuit 22 are attached to the first housing 61. The voltage defined by the specifications of the control IC of the electric motor 10 in the controller 20 is often lower than the voltage defined by the specifications of the electric motor 10. Therefore, the voltage supplied from the power supply unit 4 to the controller 20 is determined according to the specifications of the electric motor 10. The control circuit 22 is provided with a regulator (voltage conversion unit) 23 for converting the voltage supplied from the power supply unit 4 and generating the voltage supplied to the control IC or the like.

Next, the second housing 62 is attached to the first housing 61. At that time, the regulator 23 is in contact with and fixed to the second housing 62. With such a configuration, the regulator 23 generates heat during voltage conversion, but is in contact with the second housing 62, so that heat dissipation is ensured. Further, the second housing 62 functions as a protective member from a short circuit or damage of the electric motor 10 or the controller 20, and also functions as a mounting portion for mounting the gripping device 1 to another device such as a robot.

In the present embodiment, the regulator 23 comes into contact with the second housing 62, but may come into contact with the first housing 61. Further, in order to further improve heat dissipation, it is desirable that the first housing 61 and the second housing 62 are made of metal. As described above, the housing portion 60 is configured.

In the present embodiment, by incorporating the controller 20 in the housing portion 60, it is possible to reduce the risk of installation space, wiring, and disconnection as compared with the case where the controller 20 is provided separately from the gripping device 1. Further, the gripping device 1 can dissipate heat generated by the controller 20 and protect the controller 20.

FIG. 5 is an explanatory diagram of the assembly of the gripping device 1. FIG. 5A shows a state in which the rotational linear motion conversion mechanism portion 40 and the housing portion 60 are in the process of being assembled. When assembling the rotary linear motion conversion mechanism unit 40 and the housing portion 60, first, the rotary linear motion conversion mechanism portion 40 and the housing portion are formed by the positioning holes 60b provided in the first positioning pin 45 and the first housing 61. The position of the portion 60 is determined and fixed. Further, the second positioning pin 46 is inserted into the hole 42a provided in the pinion 42. Further, the spline shaft 42b provided in the pinion 42 is inserted into the spline hole 35a provided in the first planet carrier 35. As a result, the state after assembly of the rotational linear motion conversion mechanism portion 40 and the housing portion 60 shown in FIG. 5B is obtained. The speed reducer 30 and the pinion 42 are arranged on the same axis of the output shaft 10a of the electric motor 10 and the second positioning pin 46.

In the present embodiment, the first planet carrier 35 and the pinion 42 are connected by the spline hole 35a and the spline shaft 42, but they are connected by using a D-cut, a set screw, a press-fitting, or the like having a simpler shape. May be done. Further, the first planetary carrier 35 and the pinion 42 may be integrally configured.

When the rotational motion of the electric motor 10 is decelerated by a plurality of spur gears, or when a worm gear is used, it is necessary to provide as many gear support shafts and bearing portions as there are gears. In the present embodiment, since the speed reducer 30 is supported by one shaft and the output shaft 10a of the electric motor 10 is supported by bearings, a more compact gripping device 1 can be realized.

Further, in the gripping device, in general, a linear guide or the like extends with respect to the operating direction of the gripping member in order to secure the gripping range, and space is wasted. In the present embodiment, the electric motor 10, the speed reducer 30, and the pinion 42 that perform rotational movement are arranged at the center of the gripping device 1, and the controller 20 is arranged with respect to the operating direction of the gripping member 50, thereby wasting space. It is possible to realize a compact gripping device 1 that is not used in the above. Further, as compared with the gripping system in which the gripping device and the controller are separately installed, the entire gripping system 1000 including the gripping device 1 of the present embodiment can be further miniaturized.

Since the rotary linear motion conversion mechanism unit 40 receives the rotational force of the electric motor 10 amplified by the speed reducer 30, maintenance such as periodic grease application is required. In the present embodiment, since the rotary linear motion conversion mechanism unit 40 and the housing portion 60 are configured to be separable, maintenance is easy, and further, if any abnormality or failure occurs, the rotary linear motion conversion mechanism unit It is possible to replace the 40 and the housing portion 60 separately.

FIG. 6 is a cross-sectional view showing a state in which the gear ratio of the gripping device 1 is changed. In the gripping device 1 of FIG. 1, the speed reducer 30 has a three-stage gear unit (first gear unit 33a, second gear unit 33b, and third gear unit 33c). In the gripping device 1 of FIG. 6, the speed reducer 38 has a two-stage gear unit (first gear unit 33a and second gear unit 33b). Further, in the gripping device 1 of FIG. 6, instead of arranging the third gear unit 33c, a cylindrical spacer 63 is arranged. Thereby, the positions of the first gear unit 33a and the second gear unit 33b in the first housing 61 are defined. Further, the rotational force of the electric motor 10 is transmitted to the second gear unit 33b by using the gear 64 attached to the output shaft 10a. With such a configuration, it is possible to easily change the gear ratio. Further, since the number of parts used in place of the third gear unit 33c is small, it is possible to suppress an increase in cost.

In the present embodiment, as an example of changing the acceleration / deceleration ratio of the entire gripping device 1, a case where the speed reducer is changed from a configuration having a three-stage gear unit to a configuration having a two-stage gear unit has been described. Is not limited to this. It may be changed to a configuration having more gear units, or it may be changed to a configuration having one stage gear unit.

Further, different gear units may be used to change the acceleration / reduction ratio of the entire gripping device 1. For example, instead of the second gear unit 33b, which is an intermediate stage between the first to third gear units 33a, 33b, 33c, the second gear unit in which the gear ratios of the planetary gear 34 and the sun gear 36a are changed. A gear unit (not shown) different from 33b may be used. At this time, it is possible to prepare different variations of a plurality of gear units not only for the intermediate stage but also for the upper and lower gear units, and change the acceleration / reduction ratio of the entire gripping device 1 by replacing each gear unit. It is possible.

Further, a plurality of housing portions (not shown) including a plurality of planetary gears 34 constituting the plurality of gears and a gear unit having a changed gear ratio of the sun gear 36a are prepared, and the housing portion 60 is prepared. It is also possible to change the acceleration / deceleration ratio of the entire gripping device 1 by replacing it with a portion (not shown). Since the housing portion 60 is removable from the gripping device 1, it can be replaced with a different housing portion.

As described above, according to the configuration of the present embodiment, it is possible to provide a compact gripping device and a gripping system including the same, in which the gear ratio can be easily changed and maintained.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

1 Gripping device 10 Electric motor (drive unit)
10a output shaft (first transmission shaft)
30 Reducer 40 Rotational linear motion conversion mechanism (conversion)
42 pinion (second transmission axis)
60 Housing

Claims (7)

The drive unit that generates the rotational force and
The speed reducer to which the rotational force is transmitted and
The drive unit, the housing unit in which the speed reducer is housed, and the housing unit.
It is attached to the housing portion and has a conversion unit that converts the rotary motion of the speed reducer into a linear motion.
The first transmission shaft for transmitting the rotational force from the drive unit to the speed reducer and the second transmission shaft for transmitting the rotational force from the speed reducer to the conversion unit are the same shaft. Placed on top
The reducer has a removable gear unit and is equipped with a removable gear unit.
The gripping device, wherein the housing portion and the conversion portion are separable. The gripping device according to claim 1, wherein the housing portion includes an internal gear that meshes with a gear provided in the gear unit. It further has a control unit that is housed inside the housing unit and controls the drive unit.
The gripping device according to claim 1 or 2, wherein the control unit is arranged at a position facing the drive unit and the axis of the speed reducer. The control unit includes a voltage conversion unit for converting a voltage supplied from a power source.
The gripping device according to claim 3, wherein the voltage conversion unit is in contact with and fixed to the housing portion so as to dissipate heat to the housing portion. The gripping device according to any one of claims 1 to 4, wherein the housing portion is removable from the gripping device. The gripping device according to any one of claims 1 to 5, further comprising a gripping member attached to the conversion unit and for gripping an object to be gripped. The gripping device according to any one of claims 1 to 6.
A gripping system comprising a control device for controlling the gripping device.

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