U.S. patent application number 10/954569 was filed with the patent office on 2005-05-19 for robot arm with impact absorption structure.
Invention is credited to Chin, Woo Seok, Hwang, Hui Yun, Kim, Byung Chul, Lee, Chang Sup, Lee, Dai Gil, Lee, Hak Gu, Lee, Seung Min, Lim, Tae Seong, Suh, Jung Do.
Application Number | 20050103147 10/954569 |
Document ID | / |
Family ID | 34545539 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050103147 |
Kind Code |
A1 |
Lee, Dai Gil ; et
al. |
May 19, 2005 |
Robot arm with impact absorption structure
Abstract
A robot arm has an impact absorption structure for absorbing
impact energy caused by a collision to protect a person from injury
and the robot arm from being damaged. The robot arm includes a
plurality of rigid beams provided at both end portions thereof to
define a frame of the robot arm, and side members made of an
elastic material and provided between the plurality of rigid beams
to define an appearance of the robot arm and absorb the impact
energy. Each side member includes a sheet made of a plastic
material, a foam or honeycomb structure, and a fiber reinforced
composite material attached to the sheet.
Inventors: |
Lee, Dai Gil; (Daejeon,
KR) ; Suh, Jung Do; (Daejeon, KR) ; Lee, Chang
Sup; (Daejeon, KR) ; Lim, Tae Seong; (Daejeon,
KR) ; Chin, Woo Seok; (Daejeon, KR) ; Lee, Hak
Gu; (Daejeon, KR) ; Hwang, Hui Yun; (Daejeon,
KR) ; Lee, Seung Min; (Daejeon, KR) ; Kim,
Byung Chul; (Daejeon, KR) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Family ID: |
34545539 |
Appl. No.: |
10/954569 |
Filed: |
September 30, 2004 |
Current U.S.
Class: |
74/490.01 |
Current CPC
Class: |
F16F 7/12 20130101; B25J
19/0091 20130101; Y10T 74/20305 20150115 |
Class at
Publication: |
074/490.01 |
International
Class: |
E02F 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 1, 2003 |
KR |
2003-68433 |
Claims
We claim:
1. A robot arm having an impact absorption structure for absorbing
impact energy caused by a collision, comprising: a plurality of
rigid beams provided at both end portions of the robot arm to
define a frame of the robot arm; and side members made of an
elastic material and provided between the plurality of rigid beams
to define an appearance of the robot arm and to absorb the impact
energy, each side member including: a sheet made of a plastic
material and having a foam or honeycomb structure; and a fiber
reinforced composite material attached to the sheet.
2. The robot arm according to claim 1, wherein each side member has
a corrugated surface.
3. The robot arm according to claim 1, wherein each side member is
made by a simultaneous hardening process and includes: a hollow
core member being made of the sheet , and having a plurality of
grooves provided thereon.
4. The robot arm according to claim 3, wherein each side member
further includes: a mounting piece inserted into each of the
grooves of the hollow core member and made of a material suitable
for machining work; and a rigid structural member including the
fiber reinforced composite material and attached to each of upper,
lower, left and right side surfaces of the hollow core member, the
rigid structural member having an opening provided thereon to
expose the mounting piece to an outside of the rigid structural
member.
5. A robot arm having an impact absorption structure for absorbing
impact energy caused by a collision, the robot arm comprising: a
plurality of block members made of a rigid material and connected
with each other; and connecting members for connecting one block
member to another block member to define an appearance of the robot
arm, each connecting member being deformed by a force stronger than
a predetermined level, each connecting member including: a sheet
made of a plastic material and having a foam or honeycomb
structure; and a fiber reinforced composite material attached to
the sheet.
6. The robot arm according to claim 5, wherein each connecting unit
is made by a simultaneous hardening process and includes: a hollow
core member being made of the sheet and having a plurality of
grooves provided thereon.
7. The robot arm according to claim 6, wherein each connecting unit
further includes: a mounting piece inserted into each of the
grooves of the hollow core member and made of a material suitable
for machining work; and a rigid structural member including a fiber
reinforced composite material and attached to each of upper, lower,
left and right side surfaces of the hollow core member, wherein the
rigid structural member has an opening provided thereon to expose
the mounting piece to an outside of the rigid structural
member.
8. The robot arm according to claim 7, further comprising: a porous
sheet provided between the hollow core member and the rigid
structural member.
Description
PRIORITY CLAIM
[0001] This application claims under 35 U.S.C. .sctn. 119 the
benefit of the filing date of Oct. 1, 2003 of Korean Application
No. 2003-68433, the entire contents of which are incorporated
herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The invention relates generally to a robot arm which absorb
impact energy caused by a collision, thereby protecting a person
from injury and specific parts of the robot arm from being damaged
or broken. More particularly, the invention relates to a robot arm
with an impact absorption structure in which a replaceable part is
deformed by impact energy rather than other parts of the robot
arm.
[0004] 2. Background Information
[0005] Generally, robots have been used in a variety of industrial
fields. Industrial robots have been used in various places where it
may be dangerous to humans or it is impossible for humans to work,
for example, clean rooms, a universal space and atomic furnaces,
etc. Furthermore, there are robots which have been used in
rehabilitation for patients and for the betterment of living or for
leisure to improve and enjoy the life. The conventional robots have
been gradually more intimate in their association with people.
[0006] The conventional robots are generally produced to have a
strong structure to enhance their weight-support abilities.
Particularly, robot arms are made of thick and massive metals to
enhance the weight-support abilities. When the conventional robot
arm is involved in a collision, a person may be injured, or a
surrounding structure may be damaged. Further, the robot arm may be
badly damaged at the joint parts or drive parts. Because the
conventional robot arm is made of the metal, it requires a variety
of processes, thereby complicating its manufacturing process. The
conventional robot arm is problematic in that processing costs and
production costs increase.
[0007] To solve the foregoing drawbacks, it is required that a
robot arm has an impact absorption structure as well as the strong
structure for the desired weight-support ability. This allows a
robot arm to effectively respond undesirable motions and prevent
safety hazards from being caused by the robot arm. Specifically,
when a robot arm collides with a person or a surrounding structure,
a certain part of a robot arm rather than a person or a surrounding
structure should be easily deformed or broken. Therefore, a person
is protected from injury and specific parts of the robot arm can be
protected from being damaged.
SUMMARY
[0008] An object of the invention is to provide a robot arm with an
impact absorption structure which has a sufficient strength to
support its structure, and in which a predetermined part of the
robot arm is easily deformed or broken by impact energy higher than
a predetermined level, thereby preventing safety hazards.
[0009] In one embodiment, a robot arm with an impact absorption
structure is provided that absorbs impact energy caused by a
collision, thus protecting a person from injury and protecting
specific parts of the robot arm from being damaged or broken. The
robot arm includes a plurality of rigid beams provided along
longitudinal edges of the robot arm to define a frame of the robot
arm, and a side unit made of an elastic material and provided
between the plurality of rigid beams to define an appearance of the
robot arm and to absorb the impact energy. The side unit includes a
sheet made of a plastic material, a foam or honeycomb structure,
and a fiber reinforced composite material attached to the
sheet.
[0010] In another embodiment, a robot arm includes a plurality of
blocks made of a rigid material, and a connecting unit to connect
one block to another block, thereby defining an appearance of the
robot arm with the plurality of blocks connected to each other. The
connecting unit is deformed by a force higher than a predetermined
level, and includes a sheet made of a plastic material, a foam or
honeycomb structure, and a fiber reinforced composite material
attached to the sheet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention can be better understood with reference to the
following drawings and description. The components in the figures
are not necessarily to scale, emphasis instead being placed upon
illustrating the principles of the invention. Moreover, in the
figures, like referenced numerals designate corresponding parts
throughout the different views.
[0012] FIG. 1 is a latitudinal sectional view showing a
construction and operation of a robot arm, according to a first
embodiment;
[0013] FIG. 2 is a latitudinal sectional view showing a
construction and operation of a robot arm, according to a
modification of the first embodiment of FIG. 1;
[0014] FIGS. 3a through 3c are perspective views showing a
construction and operation of a robot arm, according to a second
embodiment, wherein:
[0015] FIG. 3a is a perspective view of the robot arm, in which a
plurality of blocks are separated from each other;
[0016] FIG. 3b is a perspective view of the robot arm, in which a
connecting unit connects one block to another block; and
[0017] FIG. 3c is a perspective view of the robot arm, in which the
connecting unit is deformed by impact energy applied to the
block;
[0018] FIG. 4 shows a process of manufacturing a side unit of the
robot arm of FIG. 1 or a connecting unit of the robot arm of FIG.
3;
[0019] FIG. 5 shows another process of manufacturing the side unit
of the robot arm of FIG. 1 or the connecting unit of the robot arm
of FIG. 3;
[0020] FIG. 6 shows a molding process of the side unit or the
connecting unit of the FIG. 4 or 5; and
[0021] FIG. 7 shows another molding process of the side unit or the
connecting unit of the FIG. 4 or 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Hereinafter, embodiments of a robot arm will be described in
detail with reference to the attached drawings.
[0023] FIG. 1 is a latitudinal sectional view showing a
construction and operation of a robot arm 10, according to a first
embodiment. FIG. 2 is a latitudinal sectional view showing a
construction and operation of a robot arm 10, according to a
modification of the first embodiment of FIG. 1. FIGS. 3A through 3C
are perspective views showing a construction and operation of a
robot arm 10, according to a second embodiment.
[0024] As shown in FIG. 1, the robot arm 10 according to the first
embodiment includes a plurality of rigid beams 30 which are
provided along longitudinal edges of the robot arm 10. The robot
arm 10 further includes a plurality of side units 20 which are
respectively provided between the pluralities of rigid beams 30.
The plurality of rigid beams 30 defines a frame of the robot arm
10, and the plurality of side units 20 defines an appearance of the
robot arm 10. Outer surfaces of the robot arm 10 except for the
longitudinal edges are surrounded by the plurality of side units 20
which are exposed to an outside of the robot arm 10. Each of the
side units 20 comprises a foam structure and a fiber reinforced
composite material. Generally, the fiber reinforced composite
material has a different strength according to directions. In the
robot arm 10, the robot arm 10 with the plurality of side units 20
has a higher strength in a longitudinal direction and has a lower
strength in a latitudinal direction. Due to the above-mentioned
construction of the robot arm 10, when external impact is applied
to the robot arm 10 in the latitudinal direction, the side unit 20
of the robot arm 10 is deformed inwardly to absorb impact energy,
as shown in FIG. 1. Therefore, when the robot arm 10 collides with
a person or a surrounding structure, the plurality of side units 20
absorb the impact energy caused by the collision. Thus, the robot
arm 10 protects the person from injury and protects the surrounding
structures and specific parts of the robot arm 10 from being
damaged or broken.
[0025] As shown in FIG. 2, a robot arm 10' is modified to include a
plurality of side units 20' which have corrugated surfaces 21 to
enhance the impact-absorbing ability of the robot arm 10'. Each of
the side units 20' with the corrugated surface 21 has a surface
area larger than the side unit 20' of FIG. 1, which does not have
any corrugated surface. Therefore, the side unit 20' with the
corrugated surface 21 is easily deformed in response to external
impact, thus enhancing its impact-absorbing ability.
[0026] The robot arm 10' may have a rigid body to absorb the impact
energy, different from the robot arm 10 shown in FIG. 1. FIGS. 3a
through 3c are perspective views showing construction and operation
of a robot arm 110, according to a second embodiment. FIG. 3a is a
perspective view of the robot arm 110, in which a plurality of
blocks 40 are separated from each other. FIG. 3b shows the robot
arm 110, in which a connecting unit 41 connects one block 40 to
another block 40. FIG. 3c is a perspective view of the robot arm
110, in which the connecting unit 41 is deformed by impact energy
applied to the block 40.
[0027] The robot arm 110 according to the second embodiment
includes the plurality of blocks 40, and the connecting unit 41 to
connect the plurality of blocks 40 to each other. Each of blocks 40
may have the same sectional structure as the robot arm 10, 10' of
the first embodiment shown in FIG. 1 or 2. The plurality of blocks
40 are connected to each other by the connecting unit 41. The
connecting unit 41 comprises a foam structure and a fiber
reinforced composite material in the same manner that is described
for the side unit 20 of the robot arm 10 according to the first
embodiment.
[0028] Each of the blocks 40 of the second embodiment is made of a
metal, so that a shape of the blocks 40 of the robot arm 110 is not
easily deformed or broken regardless of external impact applied to
the blocks 40. On the other hand, the connecting unit 41, which
connects the plurality of blocks 40 to each other, has a high
elasticity and strength lower than the blocks 40. When external
impact lower than a predetermined level is applied to one of the
plurality of blocks 40, the connecting unit 41, which has the
strength higher than the block 40, is deformed or broken as shown
in FIG. 3c. The connecting unit 41 absorbs impact energy applied to
the block 40, thereby protecting the blocks 40 or a joint part 42
which is difficult to replace and is expensive to manufacture. In
the meantime, the fiber reinforced composite material of the
connecting unit 41 has a different strength according to the
directions in the same manner as that described for the side unit
20 of the first embodiment. Thus, a manufacturer must consider the
above-mentioned specific characteristics of the fiber reinforced
composite material while attaching the fiber reinforced composite
material on the connecting unit 41.
[0029] FIG. 4 shows a process of manufacturing the side unit 20 of
the robot arm 10 of FIG. 1 or the connecting unit 41 of the robot
arm 110 of FIG. 3. FIG. 5 shows another process of manufacturing
the side unit 20 of the robot arm 10 of FIG. 1 or the connecting
unit 41 of the robot arm 110 of FIG. 3. FIG. 6 shows a molding
process of the side unit 20 or the connecting unit 41 of the FIG. 1
or 3. FIG. 7 shows another molding process of the side unit 20 or
the connecting unit 41 of the FIG. 1 or 3.
[0030] As shown in FIGS. 4 through 7, the side unit 20 of the first
embodiment or the connecting unit 41 of the second embodiment
comprises a sheet 50 to define shape of the side unit 20 or the
connecting unit 41. The sheet 50 is made of a foam or honeycomb
structure. The foam structure is a porous structure which is made
by foaming a plastic material, such as urethane,
polymethacrylimide(PMI), polyvinylchloride(PVC),
acrylonitrile-butadiene-styrene(ABS), phenol and etc. The honeycomb
structure is that a material, such as paper, aramid, aluminum and
etc., is formed to have a honeycomb pattern before being coated
with a resin material. The molding process of the sheet 50 of the
robot arm 10 will be described below, in particular, where the
sheet 50 comprises the foam structure.
[0031] As shown in FIG. 4, the robot arm 10 includes a plurality of
mounting pieces 70 that are mounted on the sheet 50. To mount the
plurality of mounting pieces 70 on the sheet 50, two methods may be
used. First, a plurality of grooves 51 may be provided on the sheet
50, so that the plurality of mounting pieces 70 is respectively
inserted into the grooves 51. Alternatively or additionally, the
plurality of mounting pieces 70 may be attached on an outer surface
of the sheet 50. After the plurality of mounting pieces 70 are
mounted on the sheet 50, a plurality of fiber reinforced composite
materials 60 may be attached on the sheet 50. The plurality of
fiber reinforced composite materials 60 are cut to expose the
plurality of mounting pieces 70 to an outside of the sheet 50.
Preferably, the fiber reinforced composite materials 60 remains a
soft state prior to the attachment on the sheet 50, because it is
very difficult to process the fiber reinforced composite material
60 once it is hardened. However, as shown in FIG. 5, if the soft
fiber reinforced composite material 60 is not prepared, the
manufacturer cuts the hardened fiber reinforced composite material
60 to provide a plurality of pieces, prior to attaching the fiber
reinforced composite materials 60 on the sheet 50. Thereafter, the
manufacturer attaches a laminated sheet 80 on the fiber reinforced
composite materials 60. The above-mentioned method has advantages
that production costs are substantially reduced by using the fiber
reinforced composite material 60, available in open market, without
any additional process.
[0032] As shown in FIG. 6, the sheet 50, on which the fiber
reinforced composite materials 60 are attached, is inserted into a
mold 100, prior to tightening the mold 100 with bolts or clamps to
compress the sheet 50 under a sufficient pressure. The mold 100 is
thereafter heated, taking into consideration thermal capacities of
both the robot structure and the mold 100. The sheet 50 and the
fiber reinforced composite materials 60 have thermal expansive
coefficients higher than that of the mold 100, so that pressure in
the mold 100 is increased in response to an increase in the
temperature of the mold 100. Thus, the fiber reinforced composite
materials 60 are hardened and attached to the sheet 50 in a
compression state. The above-mentioned process of hardening and
attaching the fiber reinforced materials 60 to the sheet 50 is
so-called a simultaneous hardening process. As shown in FIG. 7, the
robot arm 10 may further include a porous thin sheet 65, which is
provided on the fiber reinforced composite material 60 to enhance
an impact-absorbing ability of the sheet 50. As described above,
the sheet 50 of the robot arm 10, produced by the simultaneous
hardening process, does not require an additional post-process,
thus reducing its processing costs. Furthermore, because the fiber
reinforced composite materials 60 having a higher strength is
hardened, and, simultaneously, attached to the sheet 50, an
additional attaching process is not required.
[0033] Since the sheet 50 is made of the soft material, such as the
foam or honeycomb structure, and the fiber reinforced composite
material 60, surrounding the sheet 50 is not easily processed, it
is very difficult to mount separate components on the sheet 50.
Therefore, the mounting pieces 70, made of a metal or an industrial
plastic material which has a predetermined strength and is possible
for machine work, are mounted on the sheet 50, so that the desired
additional components, such as a sensor, a hydraulic apparatus,
etc., are mounted on the mounting pieces 70. Alternatively, the
sheet 50 of the robot arm 10 is easily coupled to a robot.
[0034] As described above, a robot arm with an impact absorption
structure is provided that absorbs impact energy caused when the
robot arm collides with a person or a surrounding structure,
thereby protecting a person from injury and preventing a
surrounding structure from being damaged. In addition, specific
parts of the robot arm are protected from damages.
[0035] It is therefore intended that the foregoing detailed
description be regarded as illustrative rather than limiting, and
that it be understood that it is the following claims, including
all equivalents, that are intended to define the spirit and scope
of this invention.
* * * * *