JPH07275B2 - Industrial robot - Google Patents

Description

TECHNICAL FIELD The present invention relates to an industrial robot, and more particularly to a turning structure thereof.

[Prior Art] FIG. 11 is a vertical sectional view of a conventional industrial robot with a built-in swing motor, and FIG. 12 is a sectional view taken along the line EE of FIG. In the figure, (1) is a motor, for example, a swing motor, which is provided at the center of the fixed base (2). (3) is a swivel base, which is connected to the rotary shaft (1a) of the swivel motor (1) and is rotatable via a bearing (6) to a housing (5) provided on the fixed base (2). It is fitted. (4) is an encoder attached to the swing motor (1), (7) is a cable, for example, a swivel cable, which is fixed to a swivel portion, for example, a swivel base (3) by a cable clamper (8), or On the way, it is fixed to the fixed base (2) by a cable clamper (8a), and its tip is connected to an electric device such as a motor (not shown). (9) is a base connector for receiving power, signals, etc. from the outside.

Next, this action will be described. When a signal is sent from the external power source connected to the base connector (9) to the swivel motor (1) through the swivel cable (7), the swivel motor (1) is activated and the swivel base (3) connected thereto is activated. Performing a swiveling movement, the swiveling cable (7) is pulled and moved by a cable clamp (8) attached to the swivel base (3). Therefore, the swivel cable (7) is fixed between the cable clampers (8) and (8a) even if the robot mounted on the swivel base (3) makes a swivel motion (generally ± 150 degrees). It is necessary to have a sufficient length so that it does not interfere with the turning motion of the robot by being wound around the outer circumference of the body of FIG. On the other hand, if a sufficient length is retained, the turning cable (7) as shown in FIG. 11 will be slack at the reference position (± 0 degrees).

[Problems to be Solved by the Invention] As industrial robots have become larger in recent years and the diameter of the swing motor (1) has increased, the amount of slack in the cable (7) between the cable clampers (8) and (8a) has increased. , And larger robots generally lower their center of gravity,
Since the vertical distance between the cable clampers (8) and (8a) becomes smaller, the amount of slack in the cable (7) further increases, and generally the turning cable (7) when the robot is at the reference position (± 0 degrees). ) Is pressed against the inside of the swivel base (3) as shown in FIG. Therefore, as the robot repeats the turning motion, there is a problem that the turning cable (7) is disconnected or makes noise.

In addition, the heat generated from the swing motor (1) may raise the temperature inside the robot and exceed the allowable temperature of the encoder (4). Furthermore, the swing motor (1) and the encoder (4) at the center of the robot may be used. ) Etc., it takes a lot of labor and time because it cannot be replaced or repaired unless the entire robot is disassembled. In particular, in the case of a robot or the like that has been put into a line work line in a factory, there has been a problem that the entire line work is stopped and the damage is serious.

By the way, as an improvement of the cable wiring device for a medium-sized industrial robot, there is, for example, one disclosed in Japanese Patent Laid-Open No. 62-44394. In this publication, the base is formed in a box shape, and the upper surface of the box-like base is composed of a semi-circular plate extending from the center thereof toward the base connector, and the opening edge of the semi-circular plate is reinforced. Is performed by a rib installed so as to divide this opening into two, and the lower center part of the robot is set to be hollow. Further, a fixed body for accommodating and fixing the turning motor is provided on the semi-circular plate which is the upper surface of the base, and the turning body, which covers the fixed body and is rotationally driven by the turning motor, is mounted through a bearing, Between the swivel body and the fixed body, a cable having one end connected to a cable clamper is arranged so as to hang down, and the other end of the cable is inside the box-shaped base through an insertion opening provided in the box-shaped base. To connect to the base connector, and to provide a tapered constriction portion in the lower half of the fixed body in the vicinity of the insertion port to eliminate the need for a cable clamper in the middle,
It is designed to reduce the amount of cable slack.

Further, as another improvement of the cable wiring device, there is one shown in, for example, JP-A-61-249286. In this publication, a leg portion is provided at the center of a bottomed cylindrical fixed base portion, and a rotation base is rotatably supported on the upper end of the leg portion through a speed reduction mechanism. The casing of the drive motor and the swing body, whose peripheral portion is supported by the cylindrical portion of the fixed base via the thrust bearing, and whose output shaft is connected to the speed reduction mechanism, are fixed on the rotary base, and the cable is fixed to the bottom of the fixed base. By arranging the legs around the space in the space between the rotation base and the rotation base, pulling out both ends to the swivel body side and the base connector side, and connecting them, the cable clamper in the middle is unnecessary, and the amount of cable slack We are trying to reduce this.

However, these publications also have the following problems. That is, the former one is generally developed for medium-sized industrial robots having a payload of 5 to 10 kg and a robot weight of 200 to 300 kg, and the lower center part of the robot is formed in a hollow shape. The vertical load of the robot must be received mainly by the semicircular plate that is the upper surface of the base and the rib installed at the tip of the opening edge so as to divide the opening of the semicircular plate into two parts, and it deforms in proportion to the weight of the robot. Increasing quantity is unavoidable. Further, since the action force (load) in the turning direction of the robot is mainly supported only by the bottom of the contraction section in the lower half of the fixed body, a certain size of shape is necessary. The reality is that there is a limit to the reduction of the diameter of the bottom part, and it has not been possible to achieve the expected reduction. Therefore, in order to apply the former one to a large robot having a portable weight of generally 30 to 100 kg and a robot weight of 1000 to 2000 kg, it is necessary to further increase the diameter of the bottom of the constricting unit. Further, since the amount of deformation increases in the hollow portion under the center of the robot, it is necessary to take measures to reduce the amount of deformation. Therefore, it has not been possible to sufficiently reduce the amount of slack in the cable.

The latter type is a high-rigidity speed reducer (type RV) for precision control, which is generally manufactured by Teijin Seiki, as a reduction mechanism that is interveningly arranged to rotatably support the rotation base on the upper ends of the legs in the center of the fixed base. -135A, RV-250A) is used,
This reducer has a connection diameter of 280 to 325 with the fixed base (leg).
It is as large as mm, and the diameter of the case that encloses it is even larger than that of the casing, which is almost the same size as the casing of the drive motor connected thereto. Therefore, even in the latter case, it is difficult to sufficiently reduce the amount of slack in the cable. Further, the load of the drive motor is also applied to the thrust bearing provided between the fixed base portion and the revolving body, which is a factor in accelerating the wear of the thrust bearing.

The present invention has been made in view of the above points, and an object of the present invention is to provide an industrial robot that performs a turning motion, has less slack in a turning cable, and is capable of preventing disconnection and noise generation. To do. Another object of the present invention is to obtain an industrial robot that is less affected by the heat of the swing motor.
Another object is to obtain an industrial robot that can be easily repaired and maintained.

[Means for Solving Problems] The industrial robot according to the present invention has the following configuration. That is, a fixed base having a protruding portion having a hollow portion and a base portion, the protruding portion protruding above the base portion, a motor housed in the hollow portion and fixedly supported by the protruding portion, and driven by a motor. An industrial robot comprising: a swiveling part that swivels; and a cable, one end of which is connected to an electric device supported by the swiveling part and which is arranged outside a protruding part so that the swiveling part can swivel. The projecting portion of is composed of a small-diameter leg portion extending from the base portion, a hollow curved wall portion extending from the small-diameter leg portion in a divergent shape, and a cylindrical wall portion extending from the curved wall portion. , The cable is further arranged outside the small diameter leg along the upper surface of the base part, and the fixed base is reinforced to reinforce the strength of the protruding part at a part outside the range of movement of the cable that moves with the turning of the turning part. It has a part.

Further, the projecting portion has a curved wall portion forming a hollow portion and a cylindrical wall portion with a predetermined hole through which air flows.

Further, the fixed base has a hole connecting the hollow part of the protruding part and the lower surface of the base part, and the outside air is allowed to flow into the hollow part through the hole.

Further, the swivel part and the fixed base each have an outer wall part extending outside the projecting part at a predetermined distance from the projecting part so as to surround the projecting part. Of these, the outer wall part of the swivel part has air flowing above it. And a fin that is rotatably supported on the lower portion of the hole and that rotates so as to generate a forced updraft between the outer wall portion and the protruding portion when the revolving portion turns. The forcible upward airflow allows the air in the hollow portion to be forcibly discharged through the curved wall portion forming the hollow portion and the hole provided in the tubular wall portion.

Further, the base portion has a hole between the outer wall portion and the protruding portion for allowing the outside air to flow therethrough.

Further, the curved wall portion and the tubular wall portion forming the hollow portion of the projecting portion have a detachable portion that enables predetermined inspection or repair of the motor inside the hollow portion by removing the curved wall portion and the tubular wall portion.

[Operation] In the industrial robot according to the present invention, the motor is housed in the hollow portion provided in the protruding portion of the fixed base having the base portion and the protruding portion protruding above the base portion, and the turning portion is driven by the motor. Is driven to rotate, and a cable whose one end is connected to an electric device provided in the rotating portion is arranged outside the protruding portion so that the rotating portion can be rotated.
The small-diameter leg portion extending from the base portion, the hollow curved wall portion extending from the small-diameter leg portion in a divergently-expanded shape, and the tubular wall portion extending from the curved wall portion are formed. It is arranged outside the small-diameter leg along the upper surface of the base part, and the fixed base has a reinforcing part that reinforces the strength of the protruding part at a position outside the range of movement of the cable that moves with the turning of the turning part. With this configuration, the vertical load of the robot is mainly supported by the small-diameter leg on the center line of the robot, and the amount of deformation can be suppressed. Furthermore, the action force (load) in the turning direction of the robot should be received by the multiple points supported by the reinforcement part installed in the part outside the range of movement of the cable and the small-diameter leg part that is separated from this by a certain distance. Since it is easy to secure the strength, it is possible to significantly reduce the diameter of the small diameter leg even when it is applied to a large industrial robot. The curved wall can be formed, and the amount of slack in the cable can be significantly reduced.

Further, since the projecting portion has the curved wall portion forming the hollow portion and the cylindrical wall portion with the predetermined number of holes through which air flows, the influence of heat generation of the motor can be reduced.

Further, the fixed base has a hole connecting the hollow part of the protruding part and the lower surface of the base part, and the outside air is allowed to flow into the hollow part through this hole, so that the heat generated by the motor is further increased. The effect of can be reduced.

Further, the swivel part and the fixed base each have an outer wall part extending outside the projecting part at a predetermined distance from the projecting part so as to surround the projecting part. Of these, the outer wall part of the swiveling part has air flowing above it. In addition to having a predetermined number of holes, there is a fin rotatably supported on the lower portion thereof, and a fin that rotates so as to generate a forced upward airflow between the outer wall portion and the protruding portion when the swivel portion turns, The forced updraft forces the air in the hollow portion to be forcibly discharged through the curved wall portion forming the hollow portion and the hole provided in the cylindrical wall portion, further reducing the influence of heat generation of the motor. can do.

Further, since the base portion has the hole for allowing the outside air to flow between the outer wall portion and the protruding portion, it is possible to further reduce the influence of heat generation of the motor.

In addition, the curved wall portion and the tubular wall portion that form the hollow portion of the protruding portion are provided with a removable portion that enables predetermined inspection or repair of the motor inside the hollow portion by removing, so repair and maintenance Work becomes easy.

[Embodiment] FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view taken along the line AA of FIG. 3, and FIG. 3 is a plan view of the fixing base (2) shown in FIG. In these drawings, (1) has a swing motor located at the center of the robot, (2) has a hollow portion having a substantially U-shaped cross section for housing the swing motor (1), for example, a hole (2i). In addition, in the lower part of the center of the hole (2i), a small-diameter leg (2S) for supporting the vertical load of the robot and the like is provided. Note that the fixed base (2) has a lower base (2) as shown in FIG.
j), the leg (2S) and the hole (2i), and the base (2S)
A leg (2S) projects upward from j), and a wall surrounding the hole (2i) extends above the leg (2S). The wall surrounding the hole (2i) includes a hollow curved wall portion (2k) that expands from the leg portion (2S) in a divergent shape toward the end, and a cylindrical wall portion (2k) that extends from the curved wall portion (2k). 21) consists of Leg (2S)
Since it has a small diameter as described above, this portion is a constricted portion when viewed from the entire fixing base (2).

Further, a portion formed by the curved wall portion (2k) that is a wall that surrounds the leg portion (2S), the hole portion (2i), and the tubular wall portion (21) is called a protruding portion. Further, on one side of the hole portion (2i), a reinforcing portion, for example, two ribs (2R) is provided for the robot to cope with a twisting load in the turning direction at the time of turning or a weight change during operation, Further, a space is formed outside the hole (2i) for the reciprocating movement of the cable. As shown in the figure, the two ribs (2R) project in the shape of a handle divided into two holes (2i) in the center of the fixing base (2), and are opposite to the ribs (2R). The interior of the side fixed base (2) thereby forms a large space. In addition, the central opening of the rib (2R) serves as a path for the cord that connects to the encoder (4) of the swing motor (1), and is supported from the center of the fixed base (2) by being supported at three points in this way. The position is moved to increase the central strength of the fixed base (2). (3) is a swivel base, (4) is an encoder, (5) is a housing, (6) is a bearing for swingably supporting the swivel base (3) with respect to a fixed base (2), and (7) is a robot. The swivel cable, (8) is a cable clamper provided on the swivel base (3), and (9) is a base connector provided on the fixed base (2).

Next, this action will be described. If the swivel base (3) makes a reciprocating motion while the robot is operating, the swivel cable (7)
Is pulled left and right by the cable clamper (8) fixed to the swivel (3), but a large space is formed on the opposite side of the rib (2R) inside the fixed base, and the corner part in the space is further formed. Since the curved portion of the cable is formed by the curved wall portion (2k), there is no sharp-angled interfering substance in this space portion, and the swivel cable (7) is accommodated in this space portion. In addition to being able to perform, the movement when the turning cable (7) is pulled around becomes smooth. Further, since the lower part of the swivel cable (7) is wound around or separated from the leg part (2S) provided at the lower part of the fixed base (2), the expansion and contraction of the cable (7) is absorbed, so that the swivel cable (7) is slackened. Will not occur.

Next, another embodiment of the present invention will be described.

FIG. 4 is a vertical sectional view of this embodiment, and FIG. 5 is a bottom view of FIG. 4 seen from the direction of arrow C. The same or corresponding parts as those in the above-mentioned embodiment are designated by the same reference numerals, and the description thereof will be omitted.
(2a) to (2f) are the sides, bottom and legs (2) of the fixed base (2).
Air circulation holes provided in S), (3a) is a plurality of air circulation holes provided in the upper part of the swivel base (3), (11) is plastic attached to the inner surface of the lower end of the swivel base (3), etc. Is a plurality of fins.

6 (a) and 6 (b) are front views of the fin (11) seen from the direction of the arrow B in FIG. 4, and the fin (11) is rotatably supported by a pin (12) as shown in the figure. When stopped, the swivel base (3) swivels relative to the fixed base (2) in the direction of arrow L as shown in FIG. It is supported by the pin (10a) and moves while maintaining a certain inclination angle, whereby the air is pushed up as shown by arrow S, and an ascending airflow as shown by arrow T is generated. Further, as shown in FIG. 6 (b), when the swivel base (3) swivels with respect to the fixed base (2) in the direction of the arrow R, the fins (11) fall in the opposite direction of the arrow R and the guide pin It is supported by (10) and moves while maintaining a constant inclination angle, whereby the air is pushed up as shown by arrow U and the same upward airflow shown by arrow T is generated.

Next, this action will be described. When the robot is not turning, warm air located at a high position inside the robot as indicated by a large number of arrows W shown in FIG. 4 is supplied to the air circulation hole (3a) provided on the upper part of the swivel base (3). ), And at the same time, the air circulation holes (2a), (2) provided at the bottom of the fixed base (2).
b), (2e) and (2a), (2c), (2d), the low-level cold air that has entered the hole (2i) passes through the air circulation holes (2f) on the side surface and turns. It flows into the space of the table (3) and flows out from the air circulation hole (3a).

In addition, when the robot is performing reciprocating revolving motion, the fin (11) moves together with the revolving base (3) while maintaining the inclination angle as described above, which causes a blowing effect of pushing up air. , Forcibly circulate cold air.

As shown in FIG. 4, the swivel base (3) is provided outside the curved wall (2k) and the tubular wall (21) surrounding the hole (2i) of the fixed base (2). It has an outer wall portion (3b) extending downward from the upper portion of the swivel base (3) at a predetermined distance from the (2k) and (21). The outer wall portion (3b) and the fixed base (2) side are provided. The above-mentioned arrow T is provided between each wall (2k) and (21).
Alternatively, an updraft indicated by an arrow W flows.

As described above, in this embodiment, the air holes (2a) to (2f) and (3a) are provided in the fixed base (2) and the swivel base (3).
By providing a fin (11) that forms an inclined surface corresponding to the turning direction at the lower end of the inner surface of the turning base (3),
It becomes possible to pass cold air from the lower side to the upper side inside the fixed base (2) and the swivel base (3) at all times, thereby minimizing the thermal deterioration of the motor (1) and the encoder (4). I can.

Next, still another embodiment of the present invention will be described. 7th
FIG. 8 is a longitudinal sectional view of this embodiment, FIG. 8 is an outline view of FIG. 7 seen from the direction of arrow D, and FIG. 9 is a main fixing base (2g) and a removable portion shown in FIG. FIG. 3 is a plan view of a sub fixing base (2h). In the figure, (15) is a removable cover provided on the side surface of the swivel base (3), (16)
Is a fixing bolt that connects the main fixing base (2g) and the sub fixing base (2h). The other reference numerals are the same as those described above, and the description is omitted.

Next, this action will be described. When removing the swivel motor (1) or encoder (4) for maintenance or repair, remove the robot cover (15), then remove the fixing bolts (16), and then the main fixing table (2g) to the sub fixing table. If (2h) is separated, the above-mentioned repair parts can be taken out from the inside of the fixed base (2).

FIG. 10 shows still another embodiment in which the dividing surface of the main fixing base (2g) and the sub fixing base (2h) is changed. The main fixing base (2g) is notched like a window frame. The sub fixing base (2h) is assembled and fixed so as to be fitted into the hole, and the operation and effect are exactly the same as in the case of FIG.

As described above, the housing portion of the swing motor (1) housed in the central portion of the fixed base (2) is composed of the main fixed base (2g) and the sub fixed base (2h) fixed to the main fixed base (2g) with bolts (16). By making it possible to divide, it is possible to take out and replace parts such as the swing motor from the inside without disassembling the main body of the robot, and only by removing a part of it, greatly simplifying the maintenance work of the robot. I can.

As described above, according to the present invention, the motor is housed in the hollow portion provided in the protruding portion in the fixed base having the base portion and the protruding portion protruding above the base portion. The swivel unit is swung by the swivel unit, and a cable whose one end is connected to an electric device provided in the swivel unit is arranged outside the protrusion so that the swivel unit can swivel. Formed from a small-diameter leg extending from the curved portion, a hollow curved wall extending from the small-diameter leg in a divergent manner, and a cylindrical wall extending from the curved wall. The fixed base is arranged outside the small-diameter leg along the upper surface of the part, and the fixed base has a reinforcing part that reinforces the strength of the protruding part at a position outside the range of movement of the cable that moves with the turning of the turning part. Therefore, the vertical load of the robot is It can be supported on the center line of the belt and the amount of deformation can be suppressed. Further, the action force (load) of the robot in the turning direction is supported at a plurality of points by the reinforcing portion installed at a portion outside the range of movement of the cable and the small-diameter leg portion located at a distance from the reinforcing portion. As a result, it becomes easier to secure the strength, and even when it is applied to a large industrial robot, it is possible to significantly reduce the diameter of the small diameter leg part, which allows the curved wall for the swivel cable to be installed. The portion can be formed, and the amount of slack in the cable can be significantly reduced. In addition, the movement of the cable accompanying the turning of the turning portion becomes smooth, noise can be prevented, and disconnection can be prevented, so that reliability can be improved.

Further, since the projecting portion is configured to have a predetermined number of holes through which air flows in the curved wall portion and the tubular wall portion forming the hollow portion, it is possible to reduce the influence of heat generation of the motor.

Further, the fixed base has a hole connecting the hollow part of the protruding part and the lower surface of the base part, and the outside air is circulated through the hole to the inside of the hollow part. This has the effect of reducing the effect of.

Further, the swivel part and the fixed base each have an outer wall part extending outside the projecting part at a predetermined distance from the projecting part so as to surround the projecting part. Of these, the outer wall part of the swiveling part has air flowing above it. In addition to having a predetermined number of holes, there is a fin rotatably supported on the lower portion thereof, and a fin that rotates so as to generate a forced upward airflow between the outer wall portion and the protruding portion when the swivel portion turns, The forced updraft allows the air in the hollow portion to be forcibly discharged through the curved wall portion forming the hollow portion and the hole provided in the tubular wall portion, so that the influence of the heat generation of the motor can be further reduced. effective.

Further, since the base portion has the hole for allowing the outside air to flow between the outer wall portion and the protruding portion, there is an effect that the influence of heat generation of the motor can be further reduced.

Further, since the curved wall portion and the tubular wall portion forming the hollow portion of the protruding portion are provided with a removable portion that enables predetermined inspection or repair of the motor in the hollow portion by removing,
This has the effect of facilitating repair and maintenance work.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a robot according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is a plan view of a fixing base, and FIG. FIG. 5 is a vertical sectional view of the embodiment, FIG. 5 is a bottom view seen in the direction C of FIG. 4, and FIGS. 6 (a) and 6 (b).
FIG. 7 is a front view showing the operation of the fins, FIG. 7 is a vertical sectional view of still another embodiment of the present invention, FIG. 8 is an external view of FIG. 7 as seen from the arrow D, and FIG. FIG. 10 is an outline view of still another embodiment of the present invention, FIG. 11 is a vertical sectional view of a conventional example, and FIG. 12 is an EE sectional view of FIG. (1) …… Swing motor, (2) …… Fixed base, (2i) ……
Hole (hollow part), (2j) …… base part, (2k) …… curved wall part, (21) …… cylindrical wall part, (2R) …… rib (reinforcing part),
(2S) …… Small diameter leg, (3) …… Swivel base, (7) …… Swivel cable, (8) …… Cable clamper. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (6)

[Claims] 1. A fixing base having a protrusion having a hollow portion and a base portion, the protrusion portion protruding above the base portion, and a fixing base housed in the hollow portion and fixedly supported by the protrusion portion. A motor, a swivel unit driven by the motor to swivel, and a cable having one end connected to an electric device supported by the swivel unit and arranged outside the projecting unit to enable swivel of the swivel unit. In the industrial robot provided with, the projecting portion of the fixing base includes a small-diameter leg portion extending from the base portion, and a hollow curved wall portion extending from the small-diameter leg portion in a divergent shape. A cylindrical wall portion extending from the curved wall portion, the cable is further disposed outside the small-diameter leg portion along the upper surface of the base portion, and the fixed base moves with the rotation of the rotary portion. Move the protruding part to a position outside the range of movement of the cable. An industrial robot having a reinforcing portion for reinforcing strength. 2. The industrial robot according to claim 1, wherein the projecting portion has a curved wall portion forming a hollow portion and a cylindrical wall portion having a predetermined number of holes through which air flows. 3. The fixing base has a hole connecting the hollow portion of the projecting portion and the lower surface of the base portion, and external air flows into the inside of the hollow portion through the hole. The industrial robot according to claim 1 or 2. 4. The swivel part and the fixed base each have an outer wall part extending outside the projecting part at a predetermined distance from the projecting part so as to surround the projecting part.
It has a predetermined number of holes through which air circulates, and is rotatably supported by its lower part so as to generate a forced upward airflow between its outer wall portion and the projecting portion when the swivel portion turns. It is characterized in that it has a fin that rotates in the direction of air, and that the forced ascending air current forcibly discharges the air in the hollow portion through the curved wall portion forming the hollow portion and the hole provided in the tubular wall portion. The industrial robot according to claim 2 or 3. 5. The industrial robot according to claim 4, wherein the base portion has a hole between the outer wall portion and the protruding portion for allowing the outside air to flow therethrough. 6. The curved wall portion and the tubular wall portion forming the hollow portion of the protruding portion are provided with a removable portion which enables a predetermined inspection or repair of the motor in the hollow portion by removing the curved wall portion and the cylindrical wall portion. The industrial robot according to any one of claims 1 to 5.