JPH0516092A - Dust collecting structure of orthogonal robot - Google Patents

Abstract

PURPOSE:To simplify the structure, and even the dust collecting effect by arranging dust collecting pipes provided with air intake holes along a passage for passing a connection part of a movable member and a nut passes, and connecting the dust collecting pipes to a pressure reducing means. CONSTITUTION:Dust collecting pipes 17, 18 and 20, 21 are paired with each other, and air intake holes 17a, 18a, 20a, 21a are formed in each dust collecting pipe 17, 18, 20, 21 respectively, and the air intake holes 17a, 18a are located opposite to each other in both sides of a slit 14 as a passage 16 of a connection part 16 a movable member 8 and a nut 7, and the air intake holes 20a, 21a are located opposite to each other in both sides of a slit 15. Each dust collecting pipe 17, 18, 20, 21 are connected to a negative pressure generating pump 19 so as to splash the dust to be caused by the slide-contact of the nut 7 and a ball screw 6 to a case body 2. The dust to be caused by the slid-contact of the nut 7 and the ball screw 6 is thereby splashed from the slits 14, 15 to the outside of the case body 2 through the air intake holes 17a, 18a, 20a, 21a of each dust collecting pipe 17, 18, 20, 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in order to prevent dust generated in an orthogonal robot from scattering outside the casing, arranges a dust collecting pipe whose inside is depressurized and passes it through an intake hole thereof. An object of the present invention is to provide a new orthogonal robot type dust collecting structure capable of simplifying the dust collecting structure and homogenizing the dust collecting effect by taking in dust.

[0002]

2. Description of the Related Art In recent years, various electronic-related devices are required to take measures against dust in the process of processing, and it is necessary to suppress dust generation in robots used in so-called clean room production facilities. There is.

Particularly in an orthogonal robot, a negative pressure is maintained around a portion where dust is generated so that air containing dust is sucked to prevent the cleanliness from being lowered.

As an example of a conventional dustproof structure, an actual flatbed 2
The one described in JP-A-105639 can be mentioned, and an outline thereof is shown in FIG.

In the slide mechanism b of the orthogonal robot a, a nut (not shown) in the moving member c is screwed to the ball screw d, and the moving member c is linearly moved by the rotation of the ball screw d, and the moving member c is moved. A pair of guide rails f for guiding the guided portions e provided on the side surfaces of the guide rails e are arranged in parallel with the ball screw d in the outer casing g.

The dust generated by the sliding movement of the moving member c is remarkable mainly in the contact portion between the moving member c and the ball screw d and the contact portion between the guided portions e, e and the guide rails f, f. Hollow elastic members h, h are attached to the two side faces of the member c facing the moving direction, the ball screw d is inserted through the insertion hole, and the two side faces of the guided parts e, e facing the moving direction. Hollow elastic members i, i, ...
.. is slidably attached to the guide rails f, f.

The elastic members h, h, i, i, ...
Of the hollow pipe of the moving member c and the inside of the housing of the moving member c,
j and passages k and k (only one of j and k is shown in the figure) are communicated with each other, and a negative pressure is applied. Sliding contact between the nut of the moving member c and the ball screw d and the guided portions e, e and guide After the dust generated by the sliding contact with the rails f, f is drawn into the housing of the moving member c, the air flow path m formed in the support legs 1, 1 of the work table (not shown),
It exhausts through m.

[0008]

However, in the slide mechanism b having the above-described structure, the elastic members h and i serve as mechanical stoppers when the moving member c reaches the end of its moving range. Although there is,
The problem that the structure of the elastic members h and i becomes complicated,
Since each member has to be arranged so that contact does not occur between the elastic member h and the ball screw d, or between the elastic member i and the guide rail f, high processing accuracy and positioning accuracy are required. There is.

A connecting pipe j for sucking dust
Therefore, it is difficult to reduce the manufacturing cost because it is necessary to mount the above-mentioned structure and to form the passage k.

[0010]

In order to solve the above-mentioned problems, the dust collecting structure of the orthogonal robot according to the present invention has a storage space for storing a ball screw and a nut that moves linearly by the rotation of the ball screw. A dust collecting structure of an orthogonal robot in which a casing having a casing and a passage through which a connecting portion for connecting the moving member and the nut for supporting the moving member to the outside of the casing passes are formed in the casing. The dust collecting pipe in which the holes are formed is arranged along the passage, and the dust collecting pipe is connected to the depressurizing means so that the inside of the dust collecting pipe is kept at a negative pressure.

[0011]

According to the orthogonal robot of the present invention, it is not necessary to attach an elastic member for collecting dust or to provide a pipe member connecting these with a moving member to form a dust passage, and to connect the dust collecting function. The structure can be simplified because it can be concentrated only on suction by the pipe arranged on the side of the passage through which the parts pass, and there is no need for high processing accuracy of the members, so there is no significant increase in cost. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The orthogonal robot of the present invention will be described below with reference to the illustrated embodiments.

FIG. 1 schematically shows the structure of an orthogonal robot 1 according to the first embodiment of the present invention when viewed in plan.

Reference numeral 2 is a housing, and the inner space thereof is divided into two small chambers 4 and 5 by a partition wall 3.

The small chamber 4 is provided for accommodating the ball screw 6, its supporting member, the nut 7, and the like. The ball screw 6 linearly moves the nut 7 and the moving member 8 (shown by a chain double-dashed line in FIG. 1) by its rotation, and the portions near both ends are supported by bearings 9 and 10.

The upper surface of the small chamber 4 has three top plates 11, 12, 1
Covered by 3.

Slits 14 and 1 are provided between the top plate 12 laid over the center and the top plates 11 and 13 arranged on both sides of the top plate 12.
5 extend parallel to the central axis of the ball screw 6, and these slits 14 and 15 connect the moving member 8 sliding with the nut 7 and the nut 7 to each other.
It is a passage through which 6 and 16 pass.

Dust collecting pipes 17 and 18 are mounted on the top plates 11 and 12 so as to sandwich the slit 14, respectively. One end of each of the dust collecting pipes 17 and 18 is closed, and the other end is an air pipe. Through negative pressure generating pump 1
9 is connected. And the dust collecting pipes 17, 18
Has a plurality of intake holes 17a, 17a on the surface on the slit 14 side.
, and 18a, 18a, ... are formed respectively.

Numerals 20 and 21 are dust collecting pipes, and the top plate 1
The dust collecting pipes 20 and 21 are attached on the slits 2 and 13 so as to sandwich the slit 15, respectively, and one ends of the dust collecting pipes 20 and 21 are closed, and the other ends are connected to the negative pressure generating pump 19 by an air pipe. And the dust collecting pipe 2
0 and 21 have a plurality of intake holes 20 on the surface on the slit 15 side.
a, 20a, ... Or 21a, 21a ,.

The small chamber 5 is provided for accommodating a motor 22 for rotating the ball screw 6 and the like. Komuro 4
The rotation shaft of the motor 22 disposed inside is the coupling 2
It is connected to one end of the ball screw 6 via 3.

Dust resulting from the sliding contact between the nut 7 and the ball screw 6 is sucked by the negative pressure generating pump 19 when scattered to the outside of the housing 2 through the slits 14 and 15. The dust collecting pipes 17, 18, 20, 21 are drawn into the pipes through the intake holes 17a, 18a, 20a, 21a and then discharged to the outside.

FIG. 2 is a vertical sectional view showing a main part of the orthogonal robot 1, and FIG. 3 is a horizontal sectional view taken along a plane perpendicular to the axis of the ball screw 6.

As shown in FIG. 3, the housing 2 has a base portion 2
4 and a side wall 2 erected on the side edge along the longitudinal direction thereof.
5 and 25 are integrally formed by, for example, extrusion molding of aluminum, and hood portions 26 and 26 are attached to the upper ends of the side walls 25 and 25.

That is, one end of the hood portions 26, 26 is attached to a portion near the upper end of the outer surface of the side walls 25, 25 with screws or the like, and the other end is bent inward. And, the top surface thereof is the top plate 11 described above.
And 13, on which dust collecting pipes 17 and 21 are attached, respectively.

Further, the top plate 12 has both ends in the longitudinal direction which cover the partition wall 3 and one end of the housing 2, respectively.
7, and dust collecting pipes 19 and 20 are attached to the upper surface thereof.

The dust collecting pipes 17, 18, 20, 21 are
Intake holes 1 formed in these dust collecting pipes 17 and 18 form a pair and 20 and 21 form a pair.
7a and 18a are arranged to face each other with the slit 14 sandwiched therebetween, and 20a and 21a are arranged to face each other with the slit 15 sandwiched therebetween.

These dust collecting pipes 17, 18, 20,
Since 21 has a substantially similar structure, only 17 is shown in FIG.
Shown in.

One end of the dust collecting pipe 17 is closed,
The other end is connected via a negative pressure applying section 28 to a vacuum pump (not shown) for generating negative pressure.

The diameter of the intake hole 17a (hereinafter referred to as "R") is smaller as it is closer to the end of the dust collecting pipe 17 on the side of the negative pressure applying portion 28, and in other words, as it goes away from it, in other words, the closed end. It is formed so that it becomes larger as it approaches.

This is for homogenizing the dust collection effect. In other words, when the length of the dust collection pipe is short, even if the intake holes have the same diameter, the difference in the dust collection effect due to the difference in the position of the intake holes is not so large, but If the diameter of the intake holes is made the same when the length of the pipe is long, the dust collection effect can be significantly different due to the difference in the position of the intake holes.

FIG. 5A shows a state in which the pipe 30 whose one end 29 is closed is simply decompressed, and FIG. 5B shows two holes 30a, 30a having different opening areas in the pipe 30.
It shows the state when the pressure is reduced by vacating.

In the figure, "P1" and "P2" represent pressures at different positions in the pipe, and both values are the same as long as the static state shown in FIG. 5 (a) is considered.

However, when the viscous fluid is flowing in the pipe, a pressure loss occurs due to the viscosity, and the assumption that the pressure is constant cannot be established. This is because the Reynolds number is small, and such a phenomenon becomes more remarkable as the radius of the pipe 30 is smaller.

Therefore, in order to make the air flow rate per unit time the same throughout the pipe, the product S * P of the opening area S of each intake hole and the pressure P at that position is substantially constant (Fig. In FIG. 5 (b), the opening area of the intake hole is changed so that S1 * P1 = S2 * P2) and the suction air flow rate is made uniform. This is the reason why the diameter R of the intake hole is increased and the opening area is increased as the distance from the negative pressure applying portion 28 increases in the present embodiment.

Therefore, a more uniform dust collecting effect can be expected, as compared with the case where the intake holes having the same diameter are formed unnecessarily.

Reference numerals 31, 31, 32, and 32 are through holes formed so as to penetrate the base portion 24 of the housing 2 in the longitudinal direction, and the through holes 3 located near the center of the base portion 24.
Reference numerals 1 and 31 have a laterally elongated rectangular shape and a through hole 32 located near the side wall of the base portion 24.
The cross section 32 has a vertically long rectangular shape.

Reference numeral 33 denotes a concave portion formed by the base portion 24 and the side walls 25, 25 and opening upward. The boundary wall 34 separating the concave portion and the through holes 31, 31 has ventilation holes 35, 35 ,. ... are formed, and the both are connected by these vent holes 35, 35, ....

One opening of the through holes 31, 31 is the closing plate 2.
7 and the other opening is the intake nozzle section 3
6 and 36 (only one of which is shown in FIG. 2) are fitted and sealed, and the intake nozzle portions 36 and 36 are connected to the intake speed control valves 37 and 37 to form negative pressure (not shown). It is connected to a vacuum pump for generation.

The drive mechanism of the orthogonal robot 1 has the same structure as before.

That is, the moving member 8 connected to the nut 7
(Indicated by a chain double-dashed line in FIG. 3) is a connecting portion 16,
It is supported on the outside of the housing 2 by 16, and the connecting portions 16 and 16 can slide through the slits 14 and 15, respectively.

However, the dust generation in the orthogonal robot 1 is mainly caused by the ball screw 6, the nut 7, the bearings 9 and 10.
However, when the nut 7 and the moving member 8 move in the small chamber 4 due to the rotation of the ball screw 6, the nut 7 and the moving member 8 are located on the opposite side of the slits 14 and 15 from the traveling direction of the nut 7 and the moving member 8. The outside air is small chamber 4 through the part
A kind of pumping action occurs in which air containing dust tends to be scattered to the outside of the small chamber 4 from the slit portion located inside the traveling direction of the nut 7 and the moving member 8.

In this embodiment, the slit 1 is used as described above.
A pair of dust collecting pipes 17, 18 and 20, 21 are arranged on both sides of 4, 15 respectively, and the dust generated in the small chamber 4 is introduced into the pipes through these intake holes 17a, 18a, 20a, 21a, Since it is finally discharged to the outside,
It is possible to prevent the atmospheric pressure inside the small chamber 4 from rising above the atmospheric pressure outside, and prevent the dust generated in the small chamber 4 from escaping out of the housing 2.

The dust falling in the small chamber 4 is drawn into the through holes 31, 31 through the ventilation holes 35, 35, ... And then discharged to the outside.

By the way, in the dust collecting structure of the orthogonal robot 1 described above, the dust collecting pipes 17, 18, 2 are simply used.
Even if the air intake holes 17a, 18a, 20a, 21a are provided at 0 and 21 at regular intervals, a considerable dust collecting effect can be expected, but a place where the nut 7 and the moving member 8 are particularly frequently located in the sliding range. 6A and 6B, the intake holes 17a of the dust collecting pipe 17 are not uniformly formed, and the intake holes 17a are not provided in places where the nut 7 frequently exists, as shown by an arrow A in FIG. It is advisable to increase the amount of suctioned air per unit time by forming a larger number than in other places and making the distribution uneven.

The graph shown in the upper part of FIG. 6 conceptually shows the relationship between the position (horizontal axis) of the nut 7 and the frequency with which the nut 7 exists at that position.

Further, the bearings 9 and 10 and the ball screw 6
It is desirable to form a large number of intake holes in the area near the bearings 9 and 10 on the outer peripheral surface of the dust collecting pipe for dust generation due to sliding contact with.

At this time, it is practical to open the number of intake holes in excess of the number required in advance, and to block unnecessary holes with a blindfold pin or the like, which is excellent in terms of design flexibility. There is.

7 to 9 show a second embodiment 1A of the present invention.
Is shown.

In the first embodiment described above, in a small-scale robot, when the intake holes of the dust collecting pipes are short and relatively densely arranged, the dust collecting effect is improved. There is no problem, but in a large robot, the length of the dust collection pipe inevitably becomes long, and if you try to form the intake holes with the same density as in the case of a small robot, the number of holes will increase,
Further, if the opening area of the intake hole is simply reduced in order to reduce the total intake air amount, there is a risk that turbulent flow may occur and dust may be scattered.

Therefore, in the second embodiment 1A, even if the opening area of the intake hole is small, a cover is provided to cover the outer circumference of the dust collecting pipe so that a laminar flow can be obtained during suction (however,
An opening for intake is provided. By this, even if the capacity of the negative pressure generating pump is small, stable intake can be performed.

The second embodiment 1A is different from the first embodiment 1 only in that the outer circumference of the dust collecting pipe is covered with a cover. Therefore, in the following description, the difference will be mainly described. The parts that are functionally different from those in the first embodiment will be denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

FIG. 7 is a vertical sectional view showing a main part of the orthogonal robot 1A, and FIG. 8 is a transverse sectional view taken along a plane perpendicular to the axis of the ball screw 6.

In the figure, 38 and 39 are dust collecting pipes 17 and 21.
Are covers that respectively cover the outer circumferences of, and each has a U-shaped cross section. These covers 38, 39
Has one end attached to the hood portions 26, 26,
Slight gaps 38a, 39a are formed between the other end and the upper surfaces of the hood portions 26, 26, respectively.
A and 39a are provided with a function as an intake slit.

Reference numeral 40 denotes a cover arranged on the top plate 12 to cover the dust collecting pipes 19 and 20, and its cross-sectional shape is U-shaped by bending both side edges. The small gaps 40a formed between the lower edge of the side surface and the top plate 12 serve as intake slits.

Although not shown, the cover 40 is attached to the partition wall 3, the closing plate 27, and a support member (not shown) attached to the top plate 12.

The groove widths of the intake slits 38a, 39a, 40a are experimentally set to 1 to 3 m when creating a laminar flow.
It is desirable to set the value to about m.

Here, without providing a dust collecting pipe, the spaces 41 and 42 defined between the covers 38 and 39 and the hood portions 26 and 26, and between the cover 40 and the top plate 12, respectively. Although it is conceivable to directly reduce the pressure in the defined space 43, the dust collecting pipe has an important meaning in the present invention because the problem of the intake unevenness described in FIG. 5 will occur again in this method. ing.

That is, in the present embodiment 1A, the intake pipes having different opening areas are formed in the dust collecting pipe to make the intake amount uniform over the entire length of the pipe, and to pass through the intake slits 38a, 39a, 40a. By producing a laminar flow, homogenization of the dust collection effect can be guaranteed.

Therefore, the dust generated in the small chamber 4 is caused by the slit 14 as the nut 7 and the moving member 8 slide.
When scattered to the outside of the small chamber 4 through 15, after being drawn into the spaces 41, 42, 43 by the laminar flow flowing through the intake slits 38a, 39a, 40a, the dust collecting pipes 17, 18 , 20 and 21 and finally discharged to the outside of the clean room.

In this embodiment, the device is devised to reduce dust generation when the duct connecting the moving member 8 and the small chamber 5 expands and contracts as the moving member 8 slides.

The duct provided between the moving member 8 and the small chamber 5 is provided when it is necessary to supply electric power or air pressure between the two, and wiring or air piping is performed through the duct. A bellows-shaped pipe member is usually used for this duct, and the flexibility of the bellows structure is utilized to fix the end of the duct to the moving member 8 and the housing 2.

However, if the moving range of the moving member 8 is long, the duct may be twisted in some cases, and by repeating this, the life of the duct may be shortened,
There is the inconvenience of causing dust.

Therefore, as shown in FIG.
L-shaped holding ducts 45 and 46 are provided so that 4 is always arranged linearly, and these are attached to the moving member 8 and the housing 2, respectively.

That is, one end of the holding duct 45 is attached to the upper surface of the moving member 8 and one end of the bellows-like pipe 44 is fixed to the other end 45a in an externally fitted state. One end of the holding duct 46 is attached to the top plate of the housing 2 that forms the small chamber 4, and the other end 46a is fixed while the other end of the bellows-like pipe 44 is externally fitted. There is.

Thus, the end portion 45a of the holding duct 45 is
With the structure in which the bellows-shaped pipe 44 is linearly bridged in a state where the end portion 46a of the holding duct 46 and the holding duct 46 face each other, the movement of the bellows-shaped pipe 44 is parallel to the sliding direction of the moving member 8. It only expands and contracts in the direction and no twist occurs.

[0066]

As is apparent from the above description, according to the present invention, a dust collecting pipe having an intake hole is attached to capture dust that is about to escape to the outside of the housing. In addition, the number of intake holes formed in the dust collection pipe can be appropriately selected so that the intake holes are distributed more densely in places where the nut moves frequently. The dust collection effect can be enhanced by arranging the above.

By increasing the opening area of the intake hole formed in the dust collecting pipe as the distance from the pressure reducing means increases, the influence of pressure loss can be reduced and the intake amount can be made uniform. A dust collecting space is defined by surrounding the pipe with a cover member, and an intake slit extending in parallel to and parallel to the passage of the connecting portion between the moving member and the nut is formed to scatter from the passage of the connecting portion. By sucking the desired dust into the dust collecting space, a laminar flow can be generated to prevent the dust from scattering.

Since the above-mentioned structure relating to the generation of laminar flow does not require a large intake flow rate, the load on the pressure reducing means can be reduced. Therefore, even if the depressurizing means is based on the negative pressure generating device in the clean room, there is an advantage that the capacity does not need to be changed on a large scale.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an orthogonal robot according to the present invention.

FIG. 2 is a vertical cross-sectional view showing the main parts of the orthogonal robot according to the first embodiment.

FIG. 3 is an enlarged cross-sectional view showing a main part of the orthogonal robot according to the first embodiment.

FIG. 4 is a side view schematically showing a dust collecting pipe.

5A and 5B are schematic views for explaining an opening area of an intake hole formed in the dust collecting pipe, FIG. 5A is a view showing a state where a pipe without an intake hole is simply decompressed, and FIG.
FIG. 6 is a diagram showing a state in which intake holes having different opening areas are opened in a pipe to reduce the pressure.

FIG. 6 is a schematic view showing the arrangement of intake holes in the dust collecting pipe.

FIG. 7 is a vertical sectional view showing a main part of an orthogonal robot according to a second embodiment.

FIG. 8 is an enlarged cross-sectional view showing a main part of an orthogonal robot according to a second embodiment.

FIG. 9 is a side view showing the structure of a piping / wiring duct.

FIG. 10 is a perspective view showing a conventional example.

[Explanation of symbols]

1 Orthogonal robot 2 housing 6 ball screws 7 nuts 8 moving members 14, 15 passage 16 Connection 17, 18, 20, 21 Dust collection pipe 17a, 18a, 20a, 21a Intake hole 19 Decompression means 1A Cartesian robot 38, 39, 40 cover member 38a, 39a, 40a Intake slit 41, 42, 43 Dust collection space

Claims (4)

[Claims] 1. A housing having a housing space for housing a ball screw and a nut that moves linearly by the rotation of the ball screw, and between the moving member and the nut for supporting the moving member outside the housing. A dust collecting structure of an orthogonal robot in which a passage through which a connecting portion to be connected passes is formed in a housing, and a dust collecting pipe having an intake hole is arranged along the passage, and the dust collecting pipe is A dust collecting structure for an orthogonal robot, characterized in that the inside of the dust collecting pipe is kept at a negative pressure by connecting to a pressure reducing means. 2. The dust collecting structure for an orthogonal robot according to claim 1, wherein the suction hole formed in the dust collecting pipe is
A dust collecting structure for an orthogonal robot, characterized in that it is arranged so as to be densely arranged in a range in which the frequency of its existence is high in the moving range of the connecting portion. 3. The dust collecting structure of an orthogonal robot according to claim 1 or 2, wherein the opening area of the intake hole formed in the dust collecting pipe is larger as the position is farther from the pressure reducing means. An orthogonal robot dust collecting structure characterized by being formed as follows. 4. The orthogonal dust collecting structure according to claim 1, 2, or 3, wherein the dust collecting pipe is surrounded by a cover member to define a dust collecting space, and the dust collecting space is connected. Of the orthogonal robot characterized in that an intake slit extending in parallel with and parallel to the passage of the part is formed so that dust that is about to scatter from the passage of the connecting part is sucked into the dust collecting space. Dust collection structure.