JP2001227612A - Rack-pinion type linear motion device - Google Patents

Abstract

(57) [Problem] To provide a rack-pinion type linear motion device in which rattling between a guide and a sliding surface in a sliding guide portion is minimized and linear motion accuracy is improved. The guide body has a substantially V-shaped cross-section, is provided with rack teeth between branched ends of the V-shape, and meshes with a guide body and rack teeth extending in a longitudinal direction orthogonal to the V-shaped cross-section. In a rack-pinion type linear motion device including a moving body 21 having a pinion 33 and capable of moving longitudinally along a guide body, the guide body extends longitudinally at both ends of the V-shape to move the moving body. It has a first sliding surface for sliding guidance and a pair of second sliding surfaces located on the outer surface of the V-shape and extending in the longitudinal direction, and the moving body is engaged with the first sliding surface. A first sliding surface and a pair of guide members 41 each having a polygonal cross section, and the guide member forms a pair of second sliding surfaces slidably engaged with the pair of second sliding surfaces, respectively. And at least one of the pair of guide members has a ball 5 screwed to the guide body. The degree of engagement of the guide member by urging the adjusting bolt 49 are possible adjustment, a pair of guide members are screwed to each mobile by fastening bolts 47.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rack-pinion type linear motion device, and more particularly, to a guide body having rack teeth and extending in a longitudinal direction and a pinion meshing with the rack teeth. The present invention relates to a rack-pinion type linear motion device including a moving body that can move in a longitudinal direction along the rack.

[0002] The rack-pinion type linear motion device as described above includes an XY plotter, an X-axis, an XY-axis, and an XYZ.
It is widely used as a linear motion device such as a machine tool or an automatic device that forms a shaft and performs linear feed.

[0003]

2. Description of the Related Art In a conventional rack-pinion type linear motion apparatus, for example, as shown in FIG. 5, a rack bar 2 having a large number of rack teeth 2a between a pair of linear guide rails 1 extending in a longitudinal direction is provided. The moving body 3 having the pinion 4 meshed with the rack teeth 2a is merely slidably mounted on the linear guide rail 1.

[0004] Similarly, a construction in which a moving body is merely slidably mounted on a linear guide rail is disclosed in Japanese Patent Laid-Open No. Hei 8-21.
It can also be found in the linear motion devices described in Japanese Patent Application Laid-Open No. 6067 and JP-A-8-247246.

[0005] In such a conventional rack-pinion type linear motion device, since the slide guide portion is not specially devised, the moving body is caused by backlash generated when the teeth of the rack and the pinion mesh with each other. There was rattling, and the linear motion accuracy was not good.

[0006]

As described above, in the conventional rack-pinion type linear motion device, the linear motion accuracy was not good. Further, in order to increase the linear motion accuracy of such a rack-pinion type linear motion device, if the clearance between the guide body and the guide rail is to be reduced, the processing accuracy of both the guide body and the guide rail member is remarkably increased. It needs to be improved, which makes the resulting linear motion device extremely expensive.

[0007] Also, since a guide rail using a rack-pinion type linear motion device is generally long in the longitudinal direction,
There is a limit in trying to improve the processing accuracy of the guide rail, and therefore, the conventional apparatus cannot sufficiently increase the movement accuracy.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention minimizes the play between a guide and a sliding surface in a slide guide portion of a rack-pinion type linear motion device, thereby improving linear motion accuracy. It is an object of the present invention to provide a rack-pinion type linear motion device which is enhanced.

Another object of the present invention is to provide a rack-pinion type linear motion device having such high precision linear motion accuracy at extremely low cost.

[0010]

According to the present invention, a guide body having rack teeth and extending in a longitudinal direction and a pinion meshing with the rack teeth are provided in the guide body. In a rack-pinion type linear motion device comprising a moving body that can move in the longitudinal direction along the guide, the guide body is in a plane extending in the longitudinal direction and slides and guides the moving body. A pair of second surfaces extending in the longitudinal direction at a position separated from the first sliding surface in a direction orthogonal to the longitudinal direction and inclined from the first sliding surface in a C-shape with respect to the first sliding surface. A sliding surface, wherein the moving body has a first sliding surface engaged with the first sliding surface and a pair of second sliding surfaces respectively engaged with a pair of second sliding surfaces. Two sliding surfaces, and at least one of the pair of second sliding surfaces. It rack characterized the degree of engagement of said second sliding surface is adjustable - the pinion linear motion device, to achieve the above object.

In the present invention according to claim 1,
The first and second sliding surfaces of the guide body are wrapped by the first and second sliding surfaces of the moving body.
Since the degree of engagement between the second sliding surface and the second sliding surface is adjustable, rattling of the moving body with respect to the guide body is prevented or greatly reduced. For this reason, in the present invention, rattling at the time of rack-pinion engagement is reduced, and the linear motion accuracy of the linear moving device according to the present invention is extremely enhanced.

According to a more specific embodiment of the present invention, as described in claim 2, it has a substantially V-shaped cross section, and is provided with rack teeth between the branched ends of the V-shape. In a rack-pinion type linear motion device comprising a guide body extending in a longitudinal direction orthogonal to a cross section and a pinion meshing with the rack teeth, and a movable body movable in the longitudinal direction along the guide body, The body extends in the longitudinal direction at both ends of the V-shape and has a first sliding surface for slidingly guiding the moving body, and a pair of first sliding surfaces located on the outer surface of the V-shape and extending in the longitudinal direction. And a pair of sliding bodies respectively slidably engaged with the first sliding surface and the pair of second sliding surfaces. , And at least one of the pair of second sliding surfaces is Serial rack engagement degree of the second sliding surface, characterized in that is adjustable - the pinion linear motion device, to achieve the above object.

According to the second aspect of the present invention, the rack is incorporated between the V-shaped portions of the guide body having a substantially V-shaped cross section, thereby achieving the above-described first aspect of the invention. In addition to the function and effect, the rack-pinion type linear motion device is extremely compact.

In the present invention, the second sliding surface is provided on a pair of guide members each having a polygonal cross section, and at least one of the pair of guide members is provided with the second slide surface. The degree of engagement with the guide body can be adjusted by an adjustment bolt screwed to the guide body, and the pair of guide members are screwed to the moving body by tightening bolts, respectively. Is easy and preferable.

In the present invention, it is preferable that a ball is provided at the tip of the adjusting bolt, as described in claim 4, because the degree of engagement of the guide member can be more easily adjusted.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a partially cutaway perspective view of a first embodiment of a rack-pinion type linear motion apparatus according to the present invention. 2A is a front view of the embodiment shown in FIG. 1 (viewed in the direction of arrow A in FIG. 1), and FIG. 2B is a plan view of the embodiment shown in FIG. 1 (viewed in the direction of arrow B in FIG. 1). ). 3A is a side view of the embodiment shown in FIG. 1 (a view in the direction of arrow A in FIG. 2A), FIG. 3B is a cross-sectional view taken along the line BB of FIG. FIG. 2C is a sectional view taken along line CC of FIG.

In FIG. 1, the guide body 11 extends in the longitudinal direction (the left-right direction in FIG. 1). In this embodiment, the guide body 11 has a substantially V-shaped cross section. In addition,
In the illustrated embodiment, the bottom portion 11d of the V-shape is expanded laterally and is not strictly V-shaped. However, since the main portion of the present invention relates to the upper V-shape portion, it is substantially omitted. V
It is called a letter-shaped cross section. The material of the guide body 11 is preferably a hard anodized aluminum alloy.

A concave portion 11c is formed between the V-shaped bifurcated tips 11a and 11b of the guide body 11, and small holes 11a 'having a large number of circular cross sections are formed on the side surfaces of the tips 11a and 11b. 11b 'are formed at equal intervals (see FIG. 3B). The pin 13 has a circular cross section,
Both ends of the pin 13 straddling the recess 11c are small holes 11a ',
11b 'is rotatably fitted. In order to prevent the pins 13 from coming off in the lateral direction, a number of pinning plates 17 are provided on the outer end surfaces of the tips 11a and 11b.
Has been concluded by With the above configuration, a pin rack is formed on the guide body 11.

The upper surfaces of both end portions 11a and 11b of the guide body 11 having a substantially V-shaped cross section are each formed in a planar shape and serve as a first sliding surface. Further, the V-shaped outer wall surfaces 11e, 11
f is a flat surface in the longitudinal direction, and each is a second sliding surface. When viewed in the longitudinal direction, the second sliding surface has a downwardly closed C-shape that is closed downward as shown in FIG. 3A.

A movable body 21 having a rectangular parallelepiped shape is straddled on the guide body 11 described above. That is, the moving body 21
3A, when viewed in the longitudinal direction, has a substantially inverted U-shaped cross section as shown in FIG. 3A, and the ceiling portion 21c of the inverted U-shaped concave portion R is as described above. It comes into sliding contact with the first sliding surface of the guide body 11. Moving body 21
(The ceiling portion 21c of the inverted U-shaped concave portion R)
A sliding plate 23 made of a flat plate,
5 screwed. In FIG. 1, the front side of the moving body 21 is partially broken so that the inside of the moving body 21 can be seen. The housing constituting the moving body 21 is preferably made of an aluminum alloy to reduce the weight.

As shown in FIG. 3B, the moving body 21 is provided with an input shaft 27 which is rotatably projected in a direction orthogonal to the moving direction. That is, the input shaft 27 is rotatably supported by the moving body 21 by the pair of bearings 29,
A pinion 33 is integrally connected to the input shaft 27 by a key 31 at an intermediate portion of the bearings 29. The sliding plate 23
As shown in FIGS. 2A and 2B, a portion corresponding to the pinion 33 is open, and the pinion 33 protruding from the opening can be engaged with the pin rack including the pin 13 described above.

A rotational driving force is transmitted to the input shaft 27 by an appropriate driving means such as a driving motor (not shown), whereby the pinion 13 rotates forward or backward and straddles the guide body 11. The moving body 21 is movable in the longitudinal direction along the guide body 11.

As shown in FIGS. 3A and 3B, facing the outer wall surfaces 11e and 11f of the moving body 21 described above,
Two substantially triangular prism-shaped guide members 4 having a substantially triangular cross section
1 so that the generally triangular slope faces up,
It is attached to both legs 21a and 21b of the moving body 21. A sliding plate 43 made of a flat plate is screwed to the inclined surface of the guide member 41 having a substantially triangular cross section with a seating bolt 45 (see FIG. 3C). Sliding contact with the sliding surface. Note that FIG.
Strictly speaking, the guide member 41 shown in (a) to (c) has a trapezoidal cross section rather than a triangular cross section, but the guide member 41 may have a polygonal cross section such as a substantially triangular cross section.

Of the two legs 21a and 21b of the moving body 21, the leg 21 shown on the right side in FIGS.
A guide member 41 is brought into contact with b and fastened integrally. That is, the leg 21b of the moving body 21 is
Bolt insertion holes 21b '(see FIG. 3 (b)) are formed at intervals in the longitudinal direction of the moving body 21 in parallel with the paper surfaces of (a) and (b). 3
(See FIG. 3B) and outside of the leg 21b (FIGS. 3A and 3B).
In FIG. 2B, a pair of hexagon socket head bolts 47 are inserted from the right side in FIG.
7 'is screwed into a screw hole 41' formed in the right guide member 41, and the right guide member 41 is integrally fastened to the right leg 21b of the moving body 21 in close contact. The hexagon socket head bolt 47 is an embodiment of the tightening bolt of the present invention,
Other forms of bolts can be used.

On the other hand, on the leg 21a shown on the left side in FIGS. 3A and 3B, a guide member 41 is provided between the guide member 41 and the leg 21a with respect to the leg 21a of the moving body 21. The spacing is adjustable. Thereby, the degree of engagement between the second sliding surface formed on the slope surface and the second sliding surface of the guide body 11 can be adjusted.

That is, as shown in FIGS. 2A and 2B, the leg 21a of the moving body 21 is formed on the aforementioned leg 21b in parallel with the paper surface of FIG. 3C. The screw holes 21 are provided at substantially the same intervals in the longitudinal direction as the pair of bolt insertion holes 21b ', that is, opposed to the bolt insertion holes 21b'.
a "is formed, and a hexagon socket set screw 49 is screwed into the screw hole 21a" (see FIG. 3 (c)). The hexagon socket set screw 49 used here is one mode of the adjustment bolt of the present invention, but other forms of bolts can be used.

Hexagon socket head set screw 49 used in this embodiment
Is a type having a ball 50 at the tip called a clamping screw. By adjusting the screwing amount of the set screw 49 with hexagonal hole, it is possible to adjust the amount of protrusion of the ball 50 which comes into contact with the tip of the set screw 49 with hexagonal hole and the guide member 41 attached to the tip.
The distance between the leg and the leg 21a can be adjusted. The ball 50 makes the hexagon socket set screw 49 and the guide member 41 come into point contact with each other,
Although the adjustment of the guide member 41 is surely performed, the ball 50 may be omitted as appropriate.

Further, the leg portion 21a of the moving body 21 is spaced apart from the pair of screw holes 21a ″ in the longitudinal direction of the moving body 21 in a longitudinal direction, that is, the pair of screw holes 21a.
A pair of bolt insertion holes 21a 'is formed inside a ", and the outside of the leg portion 21a (the left side in FIGS. 3A and 3B) is formed in the bolt insertion hole 21a' (see FIG. 3B). A pair of hexagon socket head bolts 47 (see FIG. 2 (b)) is inserted from above, and the screw portion 47 'of the hexagon socket head bolt 47 is screwed into the screw hole 41' formed in the left guide member 41, and The left guide member 41 is fastened to the left leg 21b of the moving body 21 while being adjusted by the screwing amount of the set screw 49 with hexagonal hole. While being adjusted, it is fastened to the moving body 21 by the hexagon socket head bolt 47, so that the left guide member 41
The degree of engagement between the second sliding surface and the second sliding surface on the left side of the guide body 11 can be adjusted. Hex Socket Head Cap Screw 4
Reference numeral 7 denotes one embodiment of the tightening bolt of the present invention, but other forms of bolts can be used.

The sliding plates 23 and 43 constituting the first and second sliding surfaces are made of a hard anodized aluminum alloy in this embodiment. In other words, this aluminum alloy is impregnated in a solution such as oxalic acid or nitric acid, and a current is passed through it as an anode. It is an aluminum plate.

The sliding plates 23, 43 used in the present invention
Is not limited to the above-described hard anodized aluminum alloy as long as it is a sliding bearing having low friction characteristics and moderate strength. For example, it is made of tetrafluoroethylene resin (PTFE) and lead, and does not require a lubricant. A DU dry bearing or the like can also be used.

In the first embodiment of the present invention having the above structure, the moving body 21 with both guide members 41 removed is placed on the guide body 11 in a straddling state. In this state, one (right) guide member 41 is moved to the leg 21 of the moving body 21.
b is firmly fastened by the tightening bolt 47. Further, the other (left side) guide member 41 is temporarily fastened to the leg 21a by a fastening bolt 47. In this state, adjust bolt 4
In a state where the engagement between the sliding surface of the guide member 41 and the sliding surface of the guide body 11 is adjusted by 9, the (left) guide member 41 is also firmly fastened to the leg 21 a by the tightening bolt 47.

In the rack-pinion type linear motion apparatus according to the present invention having the above-described structure, when the guide member 41 is arranged horizontally as shown in FIG. The sliding between the first sliding surface formed at the tip of the character and the sliding surface formed on the ceiling of the concave portion 11c of the moving body, and the second sliding formed on the V-shaped V-shaped slope of the guide body 11 Guide member 4 attached to moving surface and moving body 21
1 by engagement with the sliding surface.

When the pinion 33 rotates, the moving body 21 moves right and left along the guide body 11. At this time, since the play at the time of sliding is extremely small, the linear motion accuracy is extremely high.
That is, in the present invention, both sides and both V-shaped surfaces of the guide body 11 are formed as sliding surfaces, and the gap therebetween is made extremely small, so that the linear motion accuracy can be sufficiently increased without excessively high processing accuracy. be able to.

As shown in the illustrated embodiment, the guide body 11 has a V-shaped cross section, and a rack is provided between the V-shaped sections. Things are obtained.

FIG. 4 shows a second embodiment of the present invention. In the embodiment shown in FIG. 4, the rack teeth are not pins,
Although the present embodiment is different from the above-described first embodiment in that it has a normal tooth profile (for example, an involute tooth profile), other configurations are the same as those of the first embodiment.

The rack-pinion type linear motion apparatus according to the embodiment of the present invention shown in FIGS. 1 and 4 can be used in a vertical direction. In the conventional linear motion device, since the moving body 21 is merely placed on the guide rail, the moving body 21 falls when the guide rail is made vertical,
It was extremely difficult to move vertically. On the other hand, in the present invention, since the moving body 21 holds the guide body 11 so as to embrace the guide body 11 from three sides, the guide body 11 may be used vertically so that the moving body 21 moves up and down. it can.

[0037]

According to the first aspect of the present invention, the first and second sliding surfaces of the guide body are wrapped by the first and second sliding surfaces of the moving body. Since the degree of engagement between the second sliding surface and the second sliding surface is adjustable, rattling of the moving body with respect to the guide body is prevented or greatly reduced. For this reason, in the present invention, rattling at the time of rack-pinion engagement is reduced, and the linear motion accuracy of the linear moving device according to the present invention is extremely enhanced.

Further, according to the present invention described in claim 2,
A rack is incorporated between the V-shaped portions of the guide body having a substantially V-shaped cross section, and in addition to the operation and effect of the invention described in claim 1, the rack-pinion type linear motion device is extremely compact. This has the effect of becoming true.

According to the third aspect of the present invention, the second sliding surface is provided on a pair of guide members each having a polygonal cross section, and at least one of the pair of guide members is provided on the guide body. The degree of engagement with the guide body can be adjusted by the screwed adjustment bolt, and the pair of guide members are screwed to the moving body by the fastening bolts, respectively, so that a rack-pinion type linear motion device can be manufactured. Adjustment becomes easy.

In this case, if a ball is provided at the tip of the adjusting bolt, the degree of engagement of the guide member can be more easily adjusted.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of a rack-pinion type linear motion apparatus according to the present invention.

FIG. 2A is a front view of the embodiment shown in FIG. 1 (A in FIG. 1);
FIG. 2B is a plan view of the embodiment shown in FIG. 1 (viewed in the direction of arrow B in FIG. 1).

3A is a side view of the embodiment shown in FIG. 1 (FIG. 2);
FIG. 2A is a cross-sectional view taken along line BB in FIG. 2A, and FIG. 2C is a cross-sectional view taken along line CC in FIG. 2A.

FIG. 4 is a partially cutaway perspective view showing a second embodiment of the rack-pinion type linear motion apparatus according to the present invention.

FIG. 5 is a perspective view showing a conventional rack-pinion type linear motion device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Guide body 11a, 11b V-shaped tip of guide body 11e, 11f V-shaped outer wall surface of guide body 13 Rack teeth (pin) 17 Pin stopper plate 21 Moving bodies 21a, 21b Both legs 23, 43 of sliding body Plate 27 Input shaft 33 Pinion 41 Guide member One 47 Tightening bolt (Hexagon socket head bolt) 49 Adjustment bolt (Hexagon socket head set screw) 50 Ball

Claims (4)

[Claims] 1. A rack-pinion type straight line comprising a guide body having rack teeth and extending in a longitudinal direction, and a moving body having a pinion meshing with the rack teeth and movable in the longitudinal direction along the guide body. In the exercise apparatus, the guide body is in a plane extending in the longitudinal direction, and has a first sliding surface for slidingly guiding the moving body, and a direction orthogonal to the longitudinal direction from the first sliding surface. And a pair of second sliding surfaces extending in the longitudinal direction and inclined in a C-shape with respect to the first sliding surface at a position apart from each other. A first sliding surface engaged with the sliding surface and a pair of second sliding surfaces slidably engaged with the pair of second sliding surfaces, respectively; At least one of the surfaces has an adjustable degree of engagement with the second sliding surface. And a rack-pinion type linear motion device. 2. A guide body having a substantially V-shaped cross section, provided with rack teeth between branched ends of the V-shape, extending in a longitudinal direction orthogonal to the V-shaped cross section, and the rack teeth. In a rack-pinion type linear motion device comprising a moving body having a pinion meshing with the guide body and being movable in the longitudinal direction along the guide body, the guide body extends in the longitudinal direction at both ends of the V-shape. A first sliding surface for slidingly guiding the moving body, and a pair of second sliding surfaces located on the outer surface of the V-shape and extending in the longitudinal direction. A first sliding surface engaged with the first sliding surface and a pair of second sliding surfaces slidably engaged with the pair of second sliding surfaces, respectively; 2 that at least one of the sliding surfaces has an adjustable degree of engagement with the second sliding surface. Characterized rack-pinion type linear motion device. 3. The second sliding surface is provided on a pair of guide members each having a polygonal cross section, and at least one of the pair of guide members is controlled by an adjusting bolt screwed onto the guide body. The rack-pinion type straight line according to claim 1 or 2, wherein the degree of engagement with the body is adjustable, and the pair of guide members are screwed to the moving body by fastening bolts, respectively. Exercise equipment. 4. The rack-pinion type linear motion apparatus according to claim 3, wherein a ball is provided at a tip of the adjustment bolt.