JPH0321315B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an industrial robot used for welding, automatic assembly, etc. erected,
The present invention relates to an industrial robot that is provided with a pair of drive sources for tilting the robot arm in mutually orthogonal directions, and that allows the robot arm to tilt in any direction by cooperation of the two drive sources.

(Prior Art) Conventionally, according to Japanese Patent Publication No. 50-26826, the arm of the upper arm of a manipulator such as a prosthetic hand is connected to the shoulder part via a universal joint, and the arm can be freely moved by the cooperation of a plurality of drive sources. It is known that robots can be tilted freely in the direction of
A robot arm is installed on the machine base via a universal joint and can be tilted in any direction using multiple drive sources.A tool such as a welding gun is attached to the upper end of the arm via the wrist, and the arm can also be extended and retracted. One idea is to allow the tool to move linearly in any direction.

(Problem to be Solved by the Invention) By the way, when the robot arm is made to be extendable and retractable, it is possible to use a cylinder type in which the arm itself is made up of a cylinder, and a cylinder type in which the arm itself is made up of a cylinder, and a cylinder type in which the arm itself is made up of two arm members.
There is a two-arm type in which one arm member moves the other arm member forward and backward using a built-in cylinder.

When configuring the above-mentioned robot arm that can freely tilt in any direction as a telescopic arm, in the case of a cylinder type, the cylinder that makes up the arm is thick-walled in order to ensure rigidity against the bending moment that acts on the arm when tilting. It is necessary to have a large diameter, which increases the manufacturing cost, and it is not suitable for robots that carry heavy objects such as welding guns. Therefore, it is preferable that the robot arm be a two-arm type. Therefore, the robot arm is composed of a cylindrical lower arm that is connected to a universal joint and a tilting drive source, and a cylindrical upper arm that is inserted into the lower arm. It is conceivable that an elevating cylinder is installed upright so that it can be inserted, and the upper arm is raised and lowered by the cylinder.

However, in this case, since the lifting cylinder is surrounded by the upper arm, the piping to the piping connection port at the upper end of the lifting cylinder must be routed through the upper arm, making the piping layout complicated. Therefore, it is desirable to be able to easily connect piping to the lifting cylinder from the outside of the lower arm, and to reduce the weight of the arm so that the robot can operate at a faster speed. It is hoped that

An object of the present invention is to provide an industrial robot that meets such demands.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a machine with:
A telescopic robot arm via a universal joint,
The robot arm is provided with a pair of drive sources that are installed vertically and tilt the robot arm in mutually orthogonal directions, and the robot arm is made to be tiltable in any direction by cooperation of the two drive sources. The arm is composed of a lower arm connected to the universal joint and the drive source, and an upper arm that is raised and lowered by a lifting cylinder installed inside the lower arm, and the lower arm has a horizontal cross section with one side open. It is formed into a U-shape, and vertically elongated linear guide members are fixed on both sides of this opening, and the upper arm is supported by the linear guide member so as to be able to move up and down. The lower arm is formed to have an inverted L-shape in cross section, and the lifting cylinder is erected along the inner surface of the side plate portion on the other side of the lower arm opposite to the leg portion, and a piping manifold is fixed to the outer surface of the side plate portion. Then, a piping led out from the manifold was directly connected to the piping connection port of the lifting cylinder through the side plate.

(Function) Since the lower arm has a U-shaped horizontal section and the upper arm has an inverted L-shaped vertical section, the weight of the arm can be reduced compared to those in which these arms are cylindrical. The side leg portions are supported by linear guide members on both sides of the open portion of the lower arm, allowing for smooth vertical movement.

In addition, since the lifting cylinder is installed upright along the inner surface of the side plate of the lower arm, the piping led out from the piping manifold fixed on the outer surface of the side plate is directly connected to the piping connection port of the lifting cylinder through the side plate. This makes it possible to simplify the piping structure. In addition, since the side plate part is the side plate part on the other side opposite to the leg part on one side of the upper arm, there is no interference between the upper arm and the lifting cylinder, and the lifting cylinder can be aligned along the side plate part. By providing this, the supporting rigidity of the lifting cylinder to the lower arm can be increased, and the lifting cylinder can effectively function as a support member for the upper arm to the lower arm, and even if the lower arm is formed into an inverted L shape, the entire robot arm can be sufficiently supported. It can ensure rigidity.

(Example) Referring to FIGS. 1 and 2, 1 indicates a machine base, 2 indicates a machine frame fixed on the machine base 1, and the machine frame 1 has the following:
A telescopic robot arm 4 is erected via a universal joint 3 attached to the machine frame 2, and a pair of drive sources 5 tilt the arm 4 in directions orthogonal to each other.
₁ and 5 ₂ , and the arm 4 can be tilted in any direction using the universal joint 3 as a fulcrum by the cooperation of both drive sources 5 ₁ and 5 ₂ .

To explain this further, in the illustrated example, the arm 4 is a lower arm 4a connected to the universal joint 3.
and an upper arm 4b supported by this so as to be able to rise and fall freely.
The arm 4 is made to extend and contract as the upper arm 4b moves up and down by a lifting cylinder 4c provided upright within the lower arm 4a.

Each of the drive sources 5 ₁ and 5 ₂ has a phase difference of 90 degrees in the circumferential direction between the front circumferential surface of the lower arm 4a and the machine base 1 so as to connect them. It is composed of cylinders arranged in pairs, and in more detail, as shown in FIGS. 1, 3, and 5, when the robot arm 4 is in an upright state, the universal joint 3 Z is the vertical line passing through the center of
The X formed by the X-axis and Z-axis of the three-axis orthogonal coordinate system
-The first cylinder ₅ which is one driving source on the Z plane
and the second cylinder ₅₂ , which is the other driving source, is positioned on the Y-Z plane formed by the Y-axis and the Z-axis.
Brackets 6 ₁ and 6 2 pivotally connect the lower ends of the cylinders 5 ₁ and 5 ₂ to the peripheral wall in the X-axis direction and the peripheral wall in the Y-axis direction of the machine frame ₂ , and the upper end of the lower arm 4a. Brackets 7 ₁ , 7 ₂ for pivotally connecting the upper ends of the piston rods of the respective cylinders 5 ₁ , 5 ₂ are attached to the circumferential surface portion in the X-axis direction and the circumferential surface portion in the Y-axis direction,
Here, the bracket ₆₁ to which the lower end of the first cylinder ₅₁ is pivotally attached is rotatable around the X-axis with respect to the machine frame 2 by means of a bearing 6a, and the second cylinder 51 is
The bracket ₆₂ to which the lower end of the machine frame ₂ is pivotally attached is also rotatable around the Y-axis with respect to the machine frame 2. According to this, the lower arm 4a is given a tilting motion in the X-axis direction due to the operation of the first cylinder ₅₁ and a tilting motion in the Y-axis direction due to the operation of the second cylinder ₅₂ . ,
By combining these movements, the lower arm 4a, and hence the robot arm 4, can be tilted in any direction. These cylinders 5 ₁ , 5 ₂ and the lifting cylinder 5 ₀ have a magnetic scale attached to the piston rod so that their positioning can be controlled with a simple structure. Be prepared.

Further, a tool mounting plate 9 is attached to the upper end of the robot arm 4, that is, the upper end of the upper arm 4b via a universal joint 8, and a tool 10 such as a welding gun can be mounted on the mounting plate 9 as appropriate.

Here, the tool mounting plate 9 is maintained in a constant position, for example, a horizontal position, by a parallel ruler mechanism 11 provided between it and the machine base 1. In the illustrated example, the mechanism 11 is maintained using a push-pull type cable. To describe this in more detail, the mounting plate 9
and the machine frame 2 on the machine stand 1, the mounting plate 9
A pair of first cables 12 ₁ , 12 ₁ that maintain horizontality in the X-axis direction and a pair of second cables 12 ₂ , 12 ₂ that maintain horizontality in the Y-axis direction are wired. One end of the core wire of the cables 12 ₁ , 12 ₁ is disposed on both sides of the machine frame 2 in the X-axis direction, and pulleys 13 ₁ ,
13 ₁ to the seat plate 1 at the lower end of the robot arm 4
The upper end of the robot arm 4 is engaged with the locking portions 14a, 14a on both sides of the mounting plate 9 in the X-axis direction through pulleys ₁₅₁ , ₁₅₁ whose other ends are respectively disposed on both sides of the mounting plate 9 in the X-axis direction. The second cables 12 2 , 12 2 are also attached to the locking portions 16 a, 16 a on both sides of the seat plate 16 in the X-axis direction, and the second cables 12 ₂ , 12 ₂ are similarly connected with one end of their core wires on both sides of the machine frame 2 in the Y-axis direction. Placed pulley 1
The locking portions _14a , _14a on both sides of the seat plate 14 in the Y-axis direction are connected to each other via pulleys ₁₅₂ , ₁₅₂ on both sides of the mounting plate 9 in the Y-axis direction, respectively. Locking portions 16a, 1 on both sides of the seat plate 16 in the Y-axis direction
It was attached to 6a. According to this, for example, when the robot arm 4 is tilted forward in the X-axis direction by the first cylinder ₅₁ , both ends of the core wire are attached to the sides of the seat plates 14, 16 at the lower and upper ends of the arm 4 in the X-axis direction. One of _the first cables 12 ₁ , which is attached to Connect the front pulley 15 ₁ to the upper seat plate 1
functions to separate it from the front side in the X-axis direction of 6,
In addition, the other first cable ₁₂₁ , which has both ends of its core wires attached to the rear side parts of the seat plates 14 and 16 in the X-axis direction, is connected to the pulley corresponding to the rear side part of the lower end of the seat plate 14 in the X-axis direction. 13 The mounting plate 9 is X by the distance from ₁ .
The rear pulley 15 ₁ in the axial direction is connected to the X of the upper end seat plate 14.
The mounting plate 9 functions to approach the rear side in the axial direction, so that even if the seat plate 14 at the upper end tilts forward and downward due to the tilting of the arm 4, the mounting plate 9 is maintained horizontally in the X-axis direction.
Further, when the arm 4 is tilted in the Y-axis direction by the second cylinder 5 ₂ , the second cables 12 ₂ and 12 ₂ function in the same manner as described above, and the mounting plate 9 is maintained horizontally in the Y-axis direction. Thus, even when the arm 4 is tilted in any direction, the mounting plate 9 is held in a horizontal position parallel to the X-Y plane formed by the X-axis and the Y-axis.
In order to allow the arm 4 to extend and contract, the first and second cables 12 ₂ and 12 ₂ are provided with slack between the cable locking plates 17 and 18 extending from the machine frame 2 and the tool mounting plate 9. Attach and wire.

In the drawing, 19 and 20 have two upper and lower guide grooves for the first cable 12 ₁ and the second cable 12 ₂ that are coaxially attached to the respective universal joints 3 and 8 on the machine frame 2 and the tool mounting plate 9. The guide drum is shown.

In order to reduce the weight of the lower arm 4a, as shown in FIG. 4, the lower arm 4a is formed into a U-shaped horizontal section with one side open, for example, the rear side, and vertically longitudinal linear guides are provided on both sides of this open part. Members 4c, 4
c is fixedly installed, and the lower arm 4b is attached to the guide member 4.
The lower arm 4a is formed in an inverted L-shape in vertical cross section with a rear leg portion 4e supported so as to be raised and lowered via rails 4d and 4c, thereby reducing the weight of the lower arm 4a. The weight was reduced as much as possible to increase the robot's operating speed.

Further, an elevating cylinder 5o is installed upright along the inner surface of the front side plate portion of the lower arm 4a facing the leg portion 4e, and the piping manifold 2 is installed on the outer surface of the side plate portion.
A pair of cylinder piping pipes 21a, 21a and a brake piping pipe 21b, 21b, which are fixedly installed and led out from the manifold 21, are connected to the upper and lower piping connection ports of the lifting cylinder 5o and the pair of left and right piping ports of the brake 5b. The piping structure can be directly connected to the piping connection port through the side plate, thereby simplifying the piping structure.

The robot arm 4 can be tilted three-dimensionally in any direction using the universal joint 3 as a fulcrum by cooperating with a pair of first and second cylinders 5 ₁ and 5 ₂ serving as driving sources. By combining the tilting movement and its telescopic movement, it is also possible to linearly move the tool 10 attached to the tool mounting plate 9 at the upper end of the arm 4. For example, as shown in FIG. The tool 10 can be moved linearly in the left-right direction by extending and contracting the arm 4 while tilting the arm 4 in the left-right direction, or as shown in FIG. It becomes possible to linearly move the tool 10 in the vertical direction by expanding and contracting the arm 4.
The tool 10 is tilted in a direction opposite to the tilting direction of the arm 4 using the universal joint 8 at the upper end as a fulcrum, and is always held in a constant position, for example, a horizontal position, and the orientation of the tool 10 changes as the arm 4 tilts. There's nothing to do.

In the above embodiment, the parallel ruler mechanism 11 is constructed using a push-pull type cable, but the mechanism is not limited to this. For example, a link that expands and contracts in synchronization with the robot arm 4 is connected to the machine frame 2 at both ends.
It is also possible to configure a parallel link type parallel ruler mechanism by connecting the tool mounting plate 9 and the tool mounting plate 9 via respective universal joints.

(Effects of the Invention) According to the present invention, the lower arm has a U-shaped horizontal section and the upper arm has an inverted L-shaped vertical section to reduce the weight of each arm, thereby reducing the weight of the robot arm and improving the robot's operation. The speed can be increased, and the lower arm of the lifting cylinder is installed vertically in the lower arm along the inner surface of the side plate on the other side of the lower arm, which is opposite to the leg section on one side of the upper arm. The support rigidity for
The lifting cylinder effectively functions as a support member for the upper arm relative to the lower arm, so that the rigidity of the entire robot arm does not decrease even if the upper arm is not shaped into a cylinder, and the lifting cylinder is provided along the inner surface of the side plate. This allows direct piping from the piping manifold fixed to the outer surface of the side plate to the lifting cylinder through the side plate, which has the effect of simplifying the piping structure and improving maintainability.

[Brief explanation of the drawing]

Fig. 1 is a front view of the robot of the present invention, Fig. 2 is a cross-sectional side view of the robot taken along the - line in Fig. 1, and Figs. 3 to 5 are respectively taken from - line to V-V line in Fig. 2. The cross-sectional view, FIG. 6, and FIG. 7 are diagrams explaining the operation, respectively. DESCRIPTION OF SYMBOLS 1... Machine base, 3... Universal joint, 4... Robot arm, 4a... Lower arm, 4b... Upper arm, 4c... Linear guide member, 4e... Leg piece, 5o... Lifting cylinder, 5 ₁ , 5 ₂ ... Drive source (cylinder), 21 ... Piping manifold, 21a,
21b...Plumbing pipe.

Claims (1)

[Claims] 1. A telescopic robot arm is erected on the machine via a universal joint, and a pair of drive sources for tilting the robot arm in mutually orthogonal directions is provided. The robot arm is capable of tilting in any direction, and the robot arm includes a lower arm connected to the universal joint and the drive source, and an upper arm that is raised and lowered by a lifting cylinder installed inside the lower arm. The lower arm is formed into a U-shaped horizontal section with one side open, linear guide members elongated in the vertical direction are fixed on both sides of this open part, and the upper arm is connected to the linear guide member. The lower arm is formed in an inverted L-shape in vertical cross section and has a leg part on one side that is supported so as to be able to rise and fall freely, and the elevating cylinder is arranged along the inner surface of the side plate part on the other side of the lower arm opposite to the leg part. 1. An industrial robot, characterized in that a piping manifold is fixedly installed on the outer surface of the side plate, and a piping pipe led out from the manifold is directly connected to a piping connection port of the lifting cylinder through the side plate.