JP2001246528A - Working system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that an arm head end is displaced by reaction force working on an arm when practicing working and high precision working cannot be performed by a working system furnished with a work holding means and a working means and provided with one of these work holding means and working means on an arm head end of a robot. SOLUTION: One of a work holding means (work holding part 3) and a working means (milling machine 4) is provided on a head end of an arm 13 of a robot 1, a first engagement part 32a is formed on the head end of the arm 13 and a second engagement part 53 is formed on a support member (guide rail 51) provided on the other of the both means 3, 4 respectively. An arm support means is constituted of the first engagement part 32a and the second engagement part 53, and these engagement parts 32a, 53 can be engaged only when the arm 13 is at a working practicing position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machining system including a work holding means and a working means, and one of the work holding means and the working means is provided at the tip of a robot arm. The present invention relates to a technique for eliminating displacement of an arm.

[0002]

2. Description of the Related Art As a conventional machining system using a robot, a work (glass product) is applied to a robot as disclosed in Japanese Patent Application Laid-Open No. 5-185349 (prior art 1).
In some cases, a workpiece is pressed against a cutting tool of a processing machine by the operation of a robot while holding the workpiece.

[0003] Japanese Patent No. 2536319 (Prior Art 2) has a machining tool provided at the tip of a robot arm, and has a brake mechanism provided between the tip of the arm and the robot body. . This brake mechanism can be switched between a follow-up mode in which the posture of the arm changes, and a fixed mode in which the posture of the arm does not change.

[0004]

First, the prior art 1 can be adopted as long as it is a machining system that performs machining with a small machining reaction force. However, only the arm connected via multiple joints supports the work, and in a machine system where a large machining reaction force acts on the arm, the rigidity of the arm in the horizontal and vertical directions is particularly insufficient. is there.
For this reason, bending of the arm and blurring in each of the above-described directions occur due to the processing reaction.

Therefore, in the configuration of the prior art 1, since the posture of the arm cannot be sufficiently maintained at the time of working, and high working accuracy cannot be obtained, the working is limited to working with a small working reaction force acting on the arm. Therefore, it cannot be used for processing with a large processing reaction force.

The prior art 2 has a higher rigidity of the arm than the prior art 1, but even with this technique, the posture of the arm cannot be sufficiently maintained.

In other words, the rigidity of the arm can be improved by setting the brake mechanism in the fixed mode. However, this brake mechanism is a so-called "stick rod", and the force in the axial direction of the stick rod is sufficient. Although it can be supported with rigidity, the rigidity in other directions, especially in the lateral direction (horizontal direction), does not improve so much, and the bending or blurring of the arm still occurs.

Further, by providing a brake mechanism,
The operation range of the arm is greatly restricted. Robots originally have the advantage of having an arm that can move freely, which allows the robot, machine tool,
Although a great degree of freedom is provided in the layout of a conveyor or the like for conveying the work, these advantages and degrees of freedom are impaired by the brake mechanism.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a first aspect of the present invention is a work holding means for holding a work, and a work for the work. In a machining system having one of these work holding means and one of the machining means at the tip of the arm of the robot, an arm supporting means for supporting the vicinity of the tip of the arm only when the arm is at the machining position is provided. The gist is that.

[0010] Because of the above, the vicinity of the tip of the arm is supported by the arm supporting means during the execution of the work, and even if a reaction force due to the work operation acts on the arm, the reaction force does not cause the arm to bend or shake. Absent.

According to a second aspect of the present invention, in the first aspect, the arm supporting means is formed on a first engaging portion formed at an end of the arm and a supporting member provided on the other of the work holding means and the working means. The gist of the invention is that the arm comprises the first engagement portion and the second engagement portion engageable only when the arm is at the work execution position. With this configuration, the vicinity of the distal end of the arm is supported by the engagement between the first engagement portion and the second engagement portion, and the effect of claim 1 is obtained.

According to a third aspect of the present invention, in the first aspect, the arm supporting means is formed on a first engaging portion formed at an end of the arm and a supporting member erected on a floor of a machining system. The gist is that the arm comprises the first engagement portion and the second engagement portion engageable only when the arm is at the work execution position. With this configuration, the vicinity of the distal end of the arm is supported by the engagement between the first engagement portion and the second engagement portion, and the effect of claim 1 is obtained.

According to a fourth aspect of the present invention, in the second or third aspect, the second engagement portion is movable following the operation of the arm while maintaining the engagement state with the first engagement portion. The gist of the configuration is as follows. With this configuration, the arm can be operated while the operation of claim 2 or 3 is ensured.

[0014]

According to the first aspect of the present invention, since the arm supporting means for supporting the vicinity of the tip of the arm is provided, even in a machining system in which a large reaction force acts on the arm by the machining operation, The reaction force does not cause bending or blurring of the arm, and enables highly accurate work.

Further, since the arm supporting means supports the tip of the arm only when the arm is at the work execution position, the operation range of the arm is not limited, and the degree of freedom of layout in the work system is impaired. Nor.

According to the second aspect of the present invention, the effect of the first aspect is exhibited by the engagement between the first engaging portion and the second engaging portion.

According to the third aspect of the present invention, since the second engaging portion constituting the work supporting means is formed on the pillar-shaped support member erected on the floor surface, the robot in the machining system is provided. The configuration other than the support member may be changed in any way, and the effect of the first aspect can be obtained without any loss of design freedom of the entire machining system.

According to the fourth aspect of the present invention, the second engagement portion is configured to be movable, so that, for example, the work area required for the work is wide, and it is necessary to operate the robot arm when performing the work. Thus, it is possible to operate the arm while ensuring that the effects of the second and third aspects are achieved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a working system according to an embodiment of the present invention will be described in detail with reference to FIGS. Note that the horizontal direction in FIG. 1 (vertical direction in FIG. 2) is referred to as an X direction, the horizontal direction in FIG. 2 is referred to as a Y direction, and the vertical direction in FIG.

As shown in FIGS. 1 and 2, the machine system mainly includes a robot 1 for holding a workpiece W, a milling machine (machining means) 4 for performing milling (machining) on the workpiece. Consists of

First, the robot 1 is a so-called horizontal articulated robot, and has a fixed base 11 fixed to a floor F of a machining system, and a column 12 erected on the fixed base.
And an articulated arm (arm) 13 connected to the column 12.

A table 12a is connected to the column 12, and the table 12a can be moved up and down in the vertical direction (Z direction) along the column 12 by a servomotor and a feed screw mechanism (table 12a). Is referred to as a first axis 21).

The table 12a has an articulated arm 13
The first arm 13b, the second arm 13c, and the wrist 13d are sequentially connected to the base 13a.

More specifically, the first arm 13b is connected to the base 13a on a vertical axis (second axis 22), and is capable of horizontal rotation about the second axis 22. Second arm 13c
Is connected to the first arm 13b on a vertical axis (third axis 23), can rotate horizontally about the third axis 23, and
It is configured to be able to rotate (rotate) around the axis 24. The wrist 13d is connected to the second arm 13c at the fifth shaft 25, is rotatable around the fifth shaft 25, and is connected to the sixth shaft 2
It is configured to be able to rotate (rotate) around 6. The turning and rotating operations of the first arm 13b, the second arm 13c, and the wrist 13d are performed by a plurality of servomotors.

A work holding section 3 (work holding means) for holding a work W is fixed to the list 13d (arm tip) of the multi-joint arm 13. This work holding part 3
Is a substantially rectangular steel plate.
A well-known clamp mechanism (not shown) is provided on a surface (work holding surface 31) opposite to the above, and the work W is held by this clamp mechanism.

On the other hand, the milling machine 4 is disposed opposite to the robot 1 and has a base 4 fixed to the floor F.
3, a processing device 41 mounted on the base 43, and a cover device 42 fixed to the base 43 so as to cover the processing device 41.

The machining device 41 includes a spindle motor 41b having a spindle 41a extending toward the robot 1, a milling cutter 41c mounted on the spindle 41a, and a direction (X) for moving the spindle motor 41b toward and away from the robot 1. (D) direction.

The cover device 42 is a box that covers the processing device 41 to prevent chips from scattering.
It has a back plate 42b and a pair of side plates 42c, and has a configuration in which the side facing the robot 1 is open.

Each of the plates 42a to 42c is made of a material and a plate thickness that exhibit sufficient rigidity as a box, and is firmly attached to the base 43 under the back plate 42b and the pair of side plates 42c. It is fixed to. The cover device configured as described above, together with the base 43 fixed to the floor F, is a rigid part (a part that is fixed to the floor F and is not displaced by an external force) in the milling machine. .

In the machine system according to the present embodiment basically configured as described above, the robot 1 includes the work holding unit 3
The workpiece W is subjected to milling with the YZ plane as a processing surface while the workpiece W is held.

In such a working mode, the processing reaction force received by the work W from the milling cutter 41c is
3 to attempt to displace the articulated arm 13.

Normally, in the robot 1, the work W
If the weight of the multi-joint arm 13 is about 70 kg,
Since it has a weight of about 00 kg, it is possible to resist the force in the Z direction (the force resilient in the vertical direction in FIG. 1) of the processing reaction force by the weight of the multi-joint arm itself. Further, the force in the X direction (the force in the direction in which the articulated arm 13 is pushed back) can be resisted by controlling the force for pushing the articulated arm 13 toward the milling machine 4.

An arm support mechanism (arm support means) is provided to resist the remaining reaction force in the Y direction, and it is a feature of this embodiment that this mechanism is provided.

The arm support mechanism supports the distal end of the articulated arm 13 of the robot 1 only when the articulated arm 13 (arm) of the robot 1 is at a position where the workpiece W is subjected to milling (work execution position). By doing
This is to prevent the displacement of the arm due to the processing reaction force. Details of this arm support mechanism will be described below.

First, the work holding portion 3 at the end of the arm of the robot 1 is provided with two locating holes 32a at two opposite corners of the work holding surface 31.
a is the first engagement portion. Specifically, the locate hole 32
a is recessed at the tip of a cylindrical member 32 provided on the work holding surface 31.

On the other hand, the milling machine 4 has a pair of guide rails 51 (right and left sides of the machining device 41 as viewed in FIG. 3) extending in the substantially vertical direction (Z direction). (A supporting member), a supporting frame 52 which is a square-shaped window frame-shaped steel plate which is engaged with the guide rail 51 and is capable of ascending and descending (Z direction), and has a window 52a cut out substantially at the center. There are provided locate pins 53 (second engagement portions) protruding conically at two diagonal positions of the above and engageable with the locate holes 32 a provided in the work holding portion 3 of the robot 1.

The guide rail 51 is fixed to an end face of the side plate 42c of the cover device 42 facing the robot 1. That is, the guide rail 51 is provided as a part of the milling machine 4 (machining means).

The support frame 52 is, for example, disclosed in
No. 5136, the rolling guide device is engaged with the guide rail 51.
The moving member 54 is engaged with the track member (corresponding to the track member in the publication) via a ball (not shown). The moving member 54 is fixed to four corners of the back surface (the surface on the milling machine side) of the support frame 52, and the support frame 52 can move (elevate) on the guide rail 51 in the Z direction and move along the guide rail. 51 does not fall off.

That is, the support frame 52 is fixed to the rigid portion (the side plate 42c of the cover device 42) of the milling machine 4 and engages with the guide rail 51 extending in the Z direction.
The guide rail can be moved in the Z direction without being displaced in the Y direction by an external force.

The support frame 52 includes gears 55a, 55
A counterweight (not shown) is connected by a chain 55c suspended from b, and functions as a weight balancer 55. Therefore, the support frame 52 stops at an arbitrary position on the guide rail 51 unless an external force is applied.

The support frame 52 is raised at the highest position (the position indicated by the solid line in FIG. 5) as the original position (the position at which processing is started). 3 and 4). The lifting device 56 includes a pair of revolving pawls 56.
a, drive mechanism 5 for turning and raising / lowering each turning claw 56a
6b.

When the support frame 52 is lifted, each of the revolving pawls 5
6a is pivoted to an angle at which it engages with the upper portion 52b of the support frame 52, and each pivot claw 56a is raised, whereby the support frame 5
2 is raised to the highest position. At the time of working, each turning claw 56a is turned at an angle at which the engagement is released. Reference numeral 57 denotes a stopper that defines the highest position of the support frame 52.

The locate hole 32a (first engaging portion) provided in the work holding portion 3 of the robot 1, the guide rail 51 (support member) provided upright on the milling machine 4, and the support frame 5
2. An arm support mechanism is constituted by the locate pin 53 (second engagement portion) provided on the support frame 52.

The two diagonal portions of the work holding portion 3 where the locating holes 32a are not formed and the two diagonal portions of the support frame 52 where the locating pins 53 are not formed, respectively. Pins 33 and 58 are protrudingly provided, and these contact pins 33 and 58
2a and the locating pin 53 are provided so as to be in contact with each other in an engaged state, so that the parallelism between the work holding portion 3 and the support frame 52 is ensured.

The operation of the machine system configured as described above will be described below. First, the robot 1 holds a work W conveyed by a conveyor or the like (not shown) by a clamp device (not shown) of the work holding unit 3. Then, while the workpiece W is kept in this state, the workpiece W is moved closer to (loaded into) the milling machine 4 by the operation of the articulated arm 13 and the spindle motor 4 of the milling machine 4 is moved.
1b is advanced toward the robot 1.

More specifically, the work holding portion 3 of the robot 1 is approached toward the support frame 52 at the highest position, and the locating hole 32a of the work holding portion 3 and the locating pin 53 of the support frame 52 are engaged. X direction (multi-joint arm 13
(In the direction to push back)). The position of the articulated arm 13 at this time is the starting end of the work execution position, and in this state, the work W is
It faces the inside of the milling machine 4 through the second window 52a.

Then, the milling cutter 41c is advanced in the X direction by the spindle feeder 41d together with the spindle motor 41b to a position shown by a two-dot chain line in FIG.

When the articulated arm 13 is lowered along the column 12 while maintaining the engagement between the engaging portions 32a and 53 of the support frame 52 and the work holding portion 3, the articulated arm 13 Since the support frame 52 moves on the guide rail 51 following the operation, the work W is integrated with the work holding unit 3 and the support frame 52, and moves along the guide rail to a position shown by a two-dot chain line in FIG. (Z direction), and milling is performed on the entire required processing area. The position of the articulated arm 13 indicated by the two-dot chain line is the end of the work execution position.

At this time, machining reaction forces in the X, Y, and Z directions act on the articulated arm 13 via the work W, and in plane cutting with a turning tool such as milling, machining on the YZ plane is performed. Reaction force is particularly problematic.

First, the force in the Z direction of the processing reaction force can be resisted by the weight of the articulated arm 13 itself, as described above. Further, the force in the X direction can be resisted by controlling the force of pressing the articulated arm 13 toward the milling machine.

With respect to the processing reaction force in the Y direction, the locating hole 32a (first engaging portion) of the work holding portion 52 and the locating pin 53 (second engaging portion) of the support frame 52 which does not displace in the Y direction. Can be resisted by engaging.

When the machining is completed in this manner, the spindle motor 41b of the machining device 41 is retracted, and the multi-joint arm 1
After the support frame 52 is raised to the highest position, the work holding unit 3 is separated from the milling machine 4 so as to disengage the locating pin 53 and the locating hole 32a. The work W is carried out toward the next process. Thus, a series of machining operations by the robot 1 and the milling machine 4 is completed.

When the work holding unit 3 of the robot 1 separates from the support frame 52, the support frame 52 is ready for the next machining operation.
The pulling device 56 is operated in order to ensure that the position in the Z direction is the highest position. The lifting device 56 uses the driving mechanism 56b to move the turning claw 56a to the upper portion 52b of the support frame 52.
And the support frame 52 is pulled up to the highest position defined by the stopper 57.

The effects of the working system according to the above embodiment will be described below. (1) The work holding unit 3 which is the tip of the arm of the robot 1
And the supporting frame 52 of the milling machine 4 by the respective engaging portions 32a,
By performing milling in a state where the workpiece is engaged via the workpiece 53, the work holding unit 3 is moved to the milling machine 4 by Y.
Direction is restricted, so that the articulated arm 1
The rigidity of the workpiece 3 itself can be performed with high accuracy while the workpiece W is held by the robot 1 even in the case of processing with a large processing reaction force while maintaining the rigidity of the conventional apparatus.

(2) Since the arm support mechanism restricts the operation of the articulated arm 13 only at the work execution position, any other operation, for example, the operation relating to the loading and unloading of the work W, is completely restricted. Therefore, the degree of freedom of the operation of the articulated arm 13 and the degree of freedom of the layout of the robot 1, the milling machine 4, the conveyor (not shown) and the like are not impaired.

(3) In this embodiment, the workpiece W and the processing device 41 need to be relatively moved in two directions (Z and X directions) for the processing operation. The relative movement is performed by the operation of the robot 1 (the robot 1
Function originally provided).

For this reason, in the milling machine 4,
It is only necessary to move the processing device 41 in one direction (X direction), and the mechanism of the milling machine 4 can be simplified as compared to having the milling machine 4 carry in both directions, so that both the cost and the installation space of the milling machine 4 are reduced. it can.

Since the milling machine 4 only needs to control the movement in one direction (X direction), the robot 1 can be moved without providing a control device in the milling machine 4.
It is sufficiently possible to cover the control in the X direction by a control device (not shown) for controlling each servo motor.
Also in this aspect, effects of cost and installation space reduction can be obtained.

(4) The loading, processing and unloading of the work W can be performed only by the robot 1 holding the work W once. As a result, since the minimum number of work holding operations is sufficient, the cycle time of the work can be reduced accordingly, and the chance of occurrence of abnormalities (such as abnormal seating of the work) at the time of holding the workpieces can be reduced, and the productivity can be improved.

The effects described in the above (3) and (4) make it possible to perform the work with high accuracy while holding the work W on the robot 1 even in the case of a work having a large reaction force. That is why.

That is, if such machining is not possible, a standard and equipped with a mechanism and a control device for controlling the movement of the machining device in three directions of X, Y and Z, and a chuck device for holding the work. In addition to using a conventional milling machine, a robot is used to load and unload workpieces into and out of the milling machine, so there is no choice but to accept the disadvantages of cost, installation space, and productivity.

The present invention is not limited to the above embodiment, but may be modified as follows. (A) Although the milling machine 4 has been exemplified as the machine tool means, it is needless to say that the present invention can be applied to other machining machines. It is also suitable for a machine system using an assembling machine.

(B) In the above embodiment, the robot 1
A work holding part (work holding means) is provided at the tip of the multi-joint arm 13 and a milling machine 4 (working means) is provided on the side facing the robot 1, as described in Japanese Patent No. 2536319 which is exemplified as a conventional technique. It is needless to say that the present invention is also suitable for a working system in which a working means is provided at the end of the robot arm and a work holding means is provided on the opposite side.

(C) The milling machine 4 is provided with a support frame 52 which can be raised and lowered, and the support frame 52 is provided with a locate pin 53 which is a second engaging portion constituting an arm support mechanism. This is because a case where the required processing area of W is wide and the workpiece W needs to be moved with respect to the processing apparatus 41 has been described as an example, and it is not necessarily required to be movable.

That is, the required processing area of the work W is narrow,
In the case where the entire area of the required machining area can be machined while the workpiece W is held at one position, the locating pin 53 is directly provided here by using the rigid portion of the milling machine 4 as a support member.
You may just plant.

(D) The guide rail 51 is shown as a component of the arm support mechanism, and the guide rail 51 is fixed to the cover device 42 of the milling machine 4 as an example. However, the guide rail 51 is not displaced by an external force. The guide rail 51 need not be provided on the cover device 42, but may be implanted on another rigid portion of the milling machine 4 (working means), for example, on the base 43. It is possible.

Furthermore, it is not necessary to provide the guide rail 51 on a component of the working means such as the cover device 42 and the base 43. That is, only the guide rail 51 is
Even if it is used standing upright on the floor surface F outside the machine tool as an independent support member, it only needs to have sufficient rigidity so that it cannot be displaced.

It should be noted that the floor surface here does not necessarily indicate the floor itself such as a work place, but a pedestal fixed to the floor surface (for example, the basic base 1 in the above-mentioned Japanese Patent Application Laid-Open No. 5-185349). It will be easily understood by those skilled in the art to include the following.

(E) The machining reaction force in the X direction (the force in the direction in which the articulated arm 13 is pushed back) is controlled by controlling the force of the articulated arm 13, but a large machining reaction force is generated in the X direction. When using for drilling, grinding, or the like, other means can be taken.

As means therefor, it is assumed that the work holding portion 3 and the support frame 52 are mechanically locked in a state where the locate hole 32a and the locate pin 53 are engaged with each other so that the distance between them is not separated. it can. Specifically, for example, a lock device having the same turning claw and drive mechanism as the lifting device 56 is provided on either the work holding portion 3 or the support frame 52, and a force in a direction of pulling the two 3 and 52 toward each other. Should work.

(F) Locating holes 32a at two diagonal locations on one of the work holding parts 3, contact pins 33 at the other two diagonal locations,
The locating pins 53 are provided at two diagonal points on the support frame 52 and the contact pins 58 are provided at two diagonal points on the other side, respectively. Since it is sufficient to engage with rigidity, the contact pins 33, 5
8 can be omitted.

It is also possible to change the contact pins 33 and 58 to locate holes and locate pins, and to engage the locate holes and locate pins at a total of four locations. Of course, it is also possible to increase or decrease the engagement from four places as appropriate.

(G) Locate hole 32a in robot 1
The locating pins 53 are provided on the milling machine 4 respectively. However, assuming a machining machine as the machining means, the machining means, which is susceptible to the chips generated during the machining, is provided with the swarf. It is merely a difficult "male" shape, and in particular, when an assembling machine is employed as a working means, there is no problem even if the "male" and "female" relationships between the locate hole and the locate pin are reversed.

Finally, technical ideas other than those described in the claims, which can be understood from the above embodiments or other examples, will be described together with their effects. (A) The machining system according to claim 4, wherein a movable body is provided which is movable on the support member by engaging with the support member, and the movable body is provided with a second engaging portion. By doing so, the effect of claim 4 is achieved. In the embodiment, the support frame 52 corresponds to a movable body.

(B) In any one of the constitutions (2) to (4) and (a), when the first engagement portion and the second engagement portion are engaged with each other, the robot arm tip and the support member are connected to each other. A machining system provided with means for restricting relative movement in a direction in which the members are separated from each other and disengaged from each other.

In this way, even if the force in the above-mentioned direction among the reaction forces generated by the work is so strong that the force exerted by the arm of the robot cannot withstand, the claims 1 to 4 and (1) The effect of any of the configurations of (1) can be surely achieved. Note that the locking device of another example (e) described above corresponds to (b) “means for regulating...”.

[Brief description of the drawings]

FIG. 1 shows a working system according to an embodiment of the present invention.
It is a side view which shows the whole structure.

FIG. 2 is a plan view showing the overall configuration.

FIG. 3 shows a machining system according to an embodiment of the present invention;
It is a front view of a milling machine (work means).

FIG. 4 is a partial side view of the milling machine (working means).

FIG. 5 is a partial side view of the machining system according to the embodiment of the present invention, which is an explanatory diagram of an operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Robot 13 Articulated arm (arm) 3 Work holding part (work holding means) 32a Locate hole (first engaging part) 4 Milling machine (working means) 41 Processing device 42 Cover device 51 Guide rail (support member) 52 Support frame (movable body) 53 Locating pin (second engaging portion) 54 Moving member F Floor surface W Work

Claims (4)

[Claims] A work system comprising a work holding means for holding a work, and a work means for performing a work on the work, wherein one of the work holding means and the work means is provided at a tip end of a robot arm. A machining system provided with arm support means for supporting the vicinity of the arm tip only when the robot is at the machining execution position. 2. The arm supporting means is formed on a first engaging portion formed at a tip of the arm and a supporting member provided on the other of the work holding means and the working means, and the arm is at a working position. The machining system according to claim 1, comprising the first engagement portion and the second engagement portion that can be engaged only when. 3. The arm support means is formed on a first engagement portion formed at the tip of the arm and a support member erected on the floor surface of the machining system, and only when the arm is at the work execution position. The machining system according to claim 1, comprising the first engagement portion and a second engagement portion engageable. 4. The machining system according to claim 2, wherein the second engagement portion is configured to be movable following the operation of the arm while maintaining the engagement state with the first engagement portion. .