JPH035953B2 - - Google Patents

Description

Detailed Description of the Invention <Technical Field> The present invention relates to a swivel table that is rotated around a vertical axis by a rotary drive machine, and a swivel table that is rotatable around a first fulcrum in the horizontal direction with respect to the swivel table. a lower arm, an upper arm rotatable with respect to the lower arm around a second fulcrum parallel to the first fulcrum, an operating element appropriately supported with respect to the upper arm, and the lower arm and the upper arm. The present invention relates to an articulated robot including first and second driving machines supported on the swivel base for rotation.

<Prior art> Conventionally, in this type of multi-jointed robot, driving machines for rotating the upper arm and the lower arm are provided on both ends of the first fulcrum of the swivel base, protruding in the axial direction of the first fulcrum. There is something I did. However, if the drive machine protrudes horizontally like this, when the swivel table rotates, the protruding end of the drive machine may come into contact with the workpiece or the worker, causing an accident resulting in injury or death. I was afraid.

In order to cope with this problem, an articulated robot shown in FIGS. 1 to 3 has been proposed. That is, a swivel table 1 is supported on a fixed member 2 and rotated around a vertical axis by a rotation drive machine (not shown).
It is rotatably supported around a fulcrum _O1 .
Further, an upper arm 6 is supported on the upper part of the lower arm 3 so as to be freely rotatable around a second fulcrum O ₂ parallel to the first fulcrum O ₁ . 19 and 19A are the _first and second brackets 9',
The first and second drive machines are supported on the swivel base 1 in upper and lower stages via the shaft 9A', and the rotation of the second drive machine 19A is controlled by the output shaft of the second drive machine 19A. The first pulley 20A and the first fulcrum
A reducer 10A supported coaxially with O ₁ and a second pulley 21 supported by the input shaft of the reducer 10A.
A, a first toothed belt 22A stretched between the first and second pulleys 20A and 21A, and a flange supported by the output shaft of the reducer 10A and integrally fastened to the lower arm 3. The rotation is transmitted to the lower arm 3 via the second rotation transmission means 23A composed of the following members.
Similarly, the rotation of the first drive machine 19 is caused by a third pulley 20 disposed on the output shaft of the first drive machine 19.
, the fourth and fifth pulleys 21' and 20' supported coaxially with the first fulcrum O ₁ , the reducer 10 supported coaxially with the second fulcrum O ₂ , and the input shaft of the reducer. the second and third teeth stretched between the third pulley 20 and the fourth pulley 21', and between the fifth pulley 20' and the sixth pulley 21, respectively; The upper arm 6 is connected to the upper arm 6 via a first rotation transmitting means 23' constituted by attached belts 22', 22 and an output shaft of a reducer that is rotatably supported by the lower arm 3 and integrally supported by the upper arm 6. transmitted to.
In this case, the upper arm 6, the lower arm 3, and the swivel base 1 are rotated appropriately to perform the appropriate work. For example, in FIG. 1, the tilting range of the upper arm 6 is 45 degrees clockwise with respect to the horizontal plane. , 25 degrees counterclockwise, and the tilt range of the lower arm 3 is a clockwise tilt angle with respect to the vertical axis; φ ₁ is 50 degrees, and a counterclockwise tilt angle with respect to the vertical axis, that is, a backward angle; φ ₂
Assuming that the angle is set at 40 degrees, the operating element 7 appropriately supported at the tip of the upper arm 6
The operating range of the tip end is the range shown by the closed curve in FIG. In this case, even if the upper arm 6 and the lower arm 3 are tilted freely, the operating element 7
It is assumed that the absolute position of is supported as appropriate so that it remains unchanged.

When the tilting ranges of the lower arm 3 and upper arm 6 are selected as described above, in FIG.
Due to the turning situation, the first and second driving machines 19, 19A supported at the ends of the first and second brackets 9', 9A' move within the operating area of the operating element 7, as shown by the two-dot chain line. to invade. For this reason, there was a drawback that the actual processing area was reduced.
Further, in the above explanation, the tilting angle of the lower arm 3 is 90 degrees, but in this case, the center of the tilting of the lower arm 3 is when the lower arm 3 is tilted forward by 5 degrees with respect to the vertical axis. As the center of tilt of the lower arm 3 tilts forward or backward with respect to the vertical plane, the turning moment of the robot increases when the lower arm is at its maximum tilt, so it is necessary to increase the driving force of the swivel base. FIG. 4 shows another conventional example of an articulated robot, in which first and second joints are used to tilt the lower arm ₃ and the upper arm 6 about the first fulcrum O1 and the first fulcrum _O2 , respectively. Drive machine 1 for rotation of 2
9 and 19A are arranged so that the axes of the drive machines 19 and 19A are parallel to the rotation axis, respectively. For example, the rotation of this second driving device 19A is caused by a rotating shaft converter 50 such as a bevel gear, a worm, or a worm gear.
The power is transmitted to the lower arm 3, which is rotatably supported around the first fulcrum _O1 , via a suitable speed reducer. The link lever 4 is rotatably supported around a first fulcrum _O1 , and the upper arm ₆ is rotatably supported around a second fulcrum O2. 4
The lower arm 3, the upper arm 6, the link rod 5, and the link lever 4 form a parallel link mechanism. The link lever 4 is rotatably supported around the first fulcrum O ₁ via the rotary shaft converter 51 similar to the above and an appropriate speed reducer.
has been communicated to.

Since the axes of the drive machines 19 and 19A for rotation mentioned above are orthogonal to the driven shaft, the first fulcrum
Rotary shaft converters 50 and 51 must be installed at both ends of O ₁ , which increases the number of parts for the robot and increases costs. Dimensions to the mounting part;
X _a and X _b are relatively large, so that when the swivel base 1 is rotated, the mounting parts of the rotational drives 19 and 19A and the ends of the rotary axis converters 50 and 51 are affected by the movement of the operating element 7. There was a risk of intrusion into the area.

<Object of the Invention> The present invention has been made in view of the above-mentioned problems, and it is possible to set the receding angle of the lower arm with respect to the vertical line as large as possible, and moreover, it is possible to effectively set the movement area of the operation element. The purpose is to provide an articulated robot with a simple structure that can be used.

<Examples> Hereinafter, the present invention will be described in detail with reference to illustrated examples.

In FIGS. 5 to 7, reference numeral 1 denotes a swivel table supported by a fixed member 2 so as to be rotatable around a vertical axis by a drive machine (not shown), and 3 and 4 respectively correspond to the swivel table 1 as described later. The lower arm and the link lever are rotatably supported around the _first fulcrum O1, 5 is the link rod rotatably supported by the link lever 4, and 6 is the second fulcrum at the other end of the lower arm 3.
The upper arm 6 is rotatably supported around _O2 , and the upper arm 6 is also rotatably supported at the other end of the link rod 5, and the upper arm 6, lower arm 3, link lever 4, and link rod 5 are connected in parallel A link mechanism is formed. 7 is attached to the free end of the upper arm 6.
The operating element is rotatably supported around a fulcrum _O3 , and for example, the operating element 7 is composed of a support member 71 and an operating tool 72. Of course, operating tool 7
2 may be, for example, an assembly tool, a paint spray gun, a welding gun, or a cutting tool for carrying out appropriate operations, or may also include an adjustment mechanism that can appropriately adjust the positions thereof.
8 and 9 are on one end side of the first fulcrum O ₁ , for example, X ₂
The first one supported on the swivel base 1 so as to be located on the direction side.
with a fixed frame and a first bracket, this first
The fixed frame 8 is the output shaft 102 of the first reducer 10.
is rotatably supported via a bearing 17 provided on the base side of the output shaft 102. Further, the first bracket 9 is connected to the first reducer 1 via bearings 15 and 16.
The input shaft 101 of 0 is rotatably supported. Note that the input shaft 101 and the output shaft 102 of the first reduction gear 10 are each disposed coaxially with the first fulcrum _O1 . For example, in the illustrated case, the reduction gear 10 is a so-called harmonic reduction gear, and is described in detail in FIGS. 6 and 7. That is, 11 is the input shaft 10
1 is an elliptical disc integrally supported by 1; 12 is an anti-friction member disposed on the outer periphery of the elliptical disc 11;
For example, an elliptical bearing or a plurality of cylindrical bodies, 13 is a cylindrical elastic bushing that is integrally fastened to the output shaft 102, and external teeth 131 of an appropriate pitch are provided on the outer periphery of the end of the elastic bushing 13. is formed.
14 is a gear body fastened to the first fixed frame 8;
Internal teeth 141 are formed on this circular inner peripheral portion. Although the internal teeth 141 and external teeth 131 have the same pitch, the internal teeth 141 have a slightly larger number of teeth, as shown in detail in FIG.
Internal teeth 1 located near the long axis of the elliptical disc 11
41 and the external teeth 131 are in mesh with each other.

The free end 901 of the first bracket 9
It projects obliquely downward with respect to the fulcrum O ₁ and outward from the swivel base 1 . Reference numeral 19 denotes a first driving machine supported by the protruding end 901 of the first bracket 9, and the free end of this first driving machine 19 is located in the _X1 direction relative to the first bracket 9, and The output shaft 191 of the first driving machine 19 is arranged to be substantially parallel to the first fulcrum _O1 . 20 and 21 are rotation transmission members integrally supported by the output shaft 191 of the first drive machine 19 and the input shaft 101 of the reducer 10, respectively;
For example, the pulley 22 is the rotation transmission member 20, 21
A first rotation transmitting means 23 is constituted by a connecting device 22, such as a toothed belt, and the rotation transmitting members 20 and 21. 2
4 is an electromagnetic brake means for braking the rotation of the input shaft 101 of the speed reducer when desired; 25 is a rotation detector; this rotation detector 25 and the output shaft 25 of the rotation detector 25;
1 and the input shaft 101 of the reducer 10, and a coupling member 28 connected between the rotation transmission members 26 and 27 constitute a rotation detection means. .

In FIG. 6, in the _X1 direction, almost the same parts as shown by the above-mentioned numerals 8 and below are arranged, and the parts corresponding to these are denoted by the numeral A. Only the structures of the second fixed frame 8A and the output shaft 102A of the second speed reducer 10A are slightly different, and the other structures are formed with the right and left sides being opposite in FIG. 6.

That is, the output shaft 102A of the second reduction gear 10A
is a bearing 17A on the base side of the output shaft 102A.
It is rotatably supported by the second fixed frame 8A via. The lower arm 3, which is integrally supported with the output shaft 102A of the second reduction gear 10A, is divided in the X direction over a predetermined section as shown in _FIG . is rotatably supported by the first fixed frame 8 via a bearing 18A. In this way, the output shaft 10 of the second reducer 10A
The lower arm 3 supported integrally with the bearing 18
Since it is rotatably supported by the first and second fixed frames 8, 8A via A, 17A, the lower arm 3 can be reliably positioned. Further, since the free end of the output shaft 102 of the first reduction gear 10 is supported by the output shaft 102A of the second reduction gear 10A via the bearing 18, the output shaft 102 of the first reduction gear 10
2 positioning is also performed reliably. Note that one end of the link lever 4 is connected to the output shaft 1 of the first reducer 10.
Since the link lever 4 is integrally supported by the link lever 4, the rotation center of the link lever 4 is accurately positioned to be coaxial with the first fulcrum _O1 . Reference numeral 29 denotes a connecting member that connects the protruding ends of the first and second brackets 9, 9A. For example, as shown in FIG.
It is arranged so as to connect the frames of A.

In the above, when the first drive machine 19 is driven, the first drive shaft, that is, the input shaft 101 is rotated via the first rotation transmission means 23, and this rotation is transmitted via the first reduction gear 10. The speed is appropriately decelerated and transmitted to the output shaft 102, and the link lever 4 rotates clockwise or counterclockwise about the first fulcrum _O1 in FIG. That is, in FIGS. 6 and 7, when the input shaft 101 and the elliptical disc 11 rotate, the meshing position between the external teeth 131 of the elastic bushing 13 and the internal teeth 141 of the gear body 14 changes accordingly. move sequentially, and the internal teeth 141 and external teeth 131
The elastic bushing 13 has a reduction ratio according to the difference in the number of teeth.
rotates. As a result, the output shaft 102 that integrally supports the elastic bush 13 rotates, and the link lever 4 that is integrally supported by the output shaft 102 rotates. The rotation of the link lever 4 causes the upper arm 6 to rotate appropriately around the second fulcrum _O2 .

On the other hand, when the second drive unit 19A is driven, the second rotation transmission means 23A and the second reduction gear 10
The lower arm 3 rotates appropriately around the first fulcrum _O1 via A. Further, the swivel base 1 is freely swiveled around a vertical axis by a drive machine (not shown).

As mentioned above, the swivel base 1, the lower arm 3 and the upper arm 6
is rotated as appropriate to perform appropriate work.

By the way, the first and second driving machines 19 and 19A for rotating the lower arm 3 and the upper arm 6 are provided with first and second driving machines that project obliquely downward with respect to the first fulcrum _{O1 and} beyond the swivel base 1. Since the first and second driving machines are disposed at the protruding ends of the second brackets 9 and 9A, the first and second driving machines hardly get in the way when the lower arm is tilted, and therefore, as shown in FIG. The tilting angle in the counterclockwise direction with respect to the vertical plane of No. 3, that is, the receding angle can be set as large as possible. Further, the first and second driving machines are provided with first and second driving machines that project obliquely downward with respect to the first fulcrum _O1 and beyond the swivel base 1.
Since the brackets 9 and 9A are disposed at the protruding ends of the brackets 9 and 9A, the first and second drive machines, the first and second brackets, etc. are not operated as operating elements regardless of the rotational state of the swivel base 1. There is no risk of intrusion into the operating area. Furthermore, since the output shafts of the first and second driving machines are each disposed substantially parallel to the first fulcrum _O1 , a rotary axis converter is not required.
Since the center of tilting of the lower arm can be set to the vertical plane, the turning moment of the robot in the maximum tilting state of the lower arm is made as small as possible, and the swivel table and the driving machine for the swivel table can be downsized. Therefore, a simple robot can be realized.

Further, the first and second brackets 9, 9A supported by the swivel base at both ends of the first fulcrum are such that the protruding ends of these brackets 9, 9A are connected to the frame of the drive machine and the connecting member 29. Because they are connected, the mechanical strength of the bracket is increased,
Therefore, even if the swivel base 1 is freely and intermittently rotated, the protruding end of the bracket will not vibrate. Of course, the first and second brackets 9, 9A
Since the frames of the first and second driving machines, which are disposed opposite to each other on the protruding ends of Since the frame body of the second driving machine is connected between the first bracket 9 and the second bracket 9A via the connecting member 29, the inertia caused by driving and stopping the swivel base is caused by the mounting of the driving machine. Therefore, there is no risk of the mounting part of the drive machine coming loose. Furthermore, by attaching the rotation detection means and the electromagnetic brake means to each of the first and second rotating shafts that are coaxially supported with the first fulcrum _O1 , the installation and fine adjustment of the rotation detection means is facilitated. It is easy to use, and since the rotation state of the driven side is detected by the rotation detection means, the upper and lower arms may be damaged due to damage to drive side parts such as the drive machines 19 and 19A and the rotation transmission means 23 and 23A. If an attempt is made to rotate in an unexpected direction, this abnormal state can be detected by the rotation detection means. In this case, if the rotating shaft is maintained in a locked state by the electromagnetic brake means in response to the detection signal, the robot can be prevented from running away. Of course, in this case, an alarm device or the like can be activated as appropriate to detect the abnormal state.

In the above explanation, the upper arm is tilted using a link lever and a link rod, but as shown in Figs. 1 to 3, combinations of a pulley and a toothed belt, a combination of a sprocket and a chain, etc. The upper arm can also be tilted by the rotation transmission means.

<Effects of the Invention> As described in detail in the above embodiment, the present invention provides first and second brackets that are diagonally downward with respect to the first fulcrum and protrude beyond the swivel base, at both ends of the first fulcrum. disposed on the swivel base, and the first and second
The output shafts of the first and second driving machines are respectively arranged parallel to the first fulcrum and the driving machines are arranged opposite to each other on the protruding ends of the bracket, and the frames of the first and second driving machines A connecting member connecting the protruding ends of the body is provided, and first and second brackets are pivotally supported on the swivel base coaxially with the first fulcrum on the mounting side of the first and second brackets, respectively. first and second rotational transmissions for respectively connecting the rotation shafts of the second drive unit and the output shafts of the first and second drive machines to rotate the upper arm and the lower arm, respectively, through appropriate reduction gears; Since the means is provided, the first and second driving machines hardly get in the way when the lower arm is tilted, so that the receding angle of the lower arm with respect to the vertical can be set as large as possible. Regardless of the rotating state of the swivel table, the first and second driving machines and the first and second
There is no risk that the bracket or the like will invade the operating area of the operating element, and therefore the operating area of the operating element can be used effectively. In addition, the above configuration eliminates the need for a rotary axis converter and allows the center of tilting of the lower arm to be the vertical axis, so the turning moment of the robot in the maximum tilting state of the lower arm is minimized. Since the swivel table and the drive machine for the swivel table can be downsized, a simple robot can be realized. Furthermore, since the protruding ends of the first and second brackets are connected to the frames of the first and second driving machines and the connecting member,
The mechanical strength of the bracket is increased, so that even if the swivel base is freely rotated, the protruding end of the bracket will not vibrate.

Further, first and second brackets disposed opposite to each other at the protruding end portions of the first and second brackets 9, 9A are provided.
Since the frames of the first and second drive machines are connected by the connection member, the connection member can be made short and lightweight. Since it is connected between the bracket 9 and the second bracket 9A, the inertia caused by driving and stopping the swivel base will hardly act on the mounting part of the drive machine, so there is no possibility that the mounting part of the drive machine will come loose. do not have. Furthermore, if rotation detection means and electromagnetic brake means are attached to each of the first and second rotating shafts coaxially supported with the first fulcrum,
The rotation detection means is easy to install and finely adjust, and even if the upper and lower arms try to rotate in an unexpected direction due to damage to drive-side parts, the rotation detection means can detect this abnormal condition. This has the advantage that appropriate electrical control can be performed.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the conventional system, Fig. 2 is a rear view of Fig. 1, Fig. 3 is a cross-sectional view taken along the line - in Fig. 1,
Fig. 4 is a perspective view showing another conventional example, Fig. 5 is a front view showing an embodiment of the present invention, and Fig. 6 is a - of Fig. 5.
7 is a cross-sectional view taken along the - line in FIG. 6; FIG. 1... Swivel base, 3... Lower arm, 6... Upper arm, 7...
...Operating element, 9...First bracket, 9A...
Second bracket, 19...First drive machine, 19
A...Second driving machine, 23...First rotation transmission means, 23A...Second rotation transmission means, 29...Connecting member.

Claims (1)

[Claims] 1. A swivel base that is rotated around a vertical axis by a rotary drive machine, a lower arm that is rotatable around a first fulcrum in a horizontal direction with respect to the swivel base, and a lower arm that is rotatable around a first fulcrum in a horizontal direction with respect to the swivel base an upper arm that is rotatable around a second fulcrum parallel to the first fulcrum; an operating element supported appropriately on the upper arm; and a swivel base for rotating the lower arm and the upper arm. In the multi-jointed robot, the first and second drive machines are arranged such that the first and second drive machines are supported by the robot, and the first and second brackets project obliquely downward from the first fulcrum and beyond the swivel base. are arranged on the swivel base at both ends of the first fulcrum, and the output shafts of the first and second driving machines are respectively parallel to the first fulcrum at the protruding ends of the first and second brackets. and arranging the driving machines opposite to each other, arranging a connecting member that connects the protruding ends of the frames of the first and second driving machines, and attaching the first and second brackets. first and second pivots coaxially supported by the swivel base at the sides thereof, respectively, coaxially with the first fulcrum;
and a rotation transmitting member that connects the rotating shaft of the first and second driving machines to the output shafts of the first and second driving machines, respectively, and rotates the upper arm and the lower arm, respectively, through an appropriate reduction gear. An articulated robot comprising first and second rotation transmitting means. 2. A swivel base that is rotated around a vertical axis by a rotary drive machine, a lower arm that is rotatable around a first fulcrum in a horizontal direction with respect to the swivel base, and a first fulcrum that is connected to the lower arm. an upper arm that is rotatable about a second fulcrum parallel to the upper arm; an operating element that is appropriately supported on the upper arm; and a first arm that is supported on the swivel base for rotating the lower arm and the upper arm. and a second driving machine, wherein the first and second brackets, which are diagonally downward with respect to the first fulcrum and protrude beyond the swivel base, are connected to the first fulcrum. The output shafts of the first and second driving machines are arranged in the projecting ends of the first and second brackets in parallel with the first fulcrum, and the driving machines are arranged opposite to each other. A connecting member is provided to connect the protruding ends of the frame bodies of the first and second driving machines, and the first fulcrum is located on the mounting side of the first and second brackets. and a first and a second shaft coaxially supported on the swivel base, respectively.
and a rotation transmitting member that connects the rotation shaft of the first and second driving machines to the output shafts of the first and second driving machines, respectively, and rotates the upper arm and the lower arm, respectively, through an appropriate reduction gear. What is claimed is: 1. An articulated robot comprising first and second rotation transmitting means, and a rotation detecting means and an electromagnetic brake means are respectively connected to the first and second rotating shafts.