JPH0314954A - linear motion device - Google Patents

Abstract

PURPOSE:To enable a speedy linear motion with an increased moving range by allowing a first moving member to perform linear motion on a base while a second moving member to perform linear motion on the first member. CONSTITUTION:A transmission member 27 is driven by means of a screw shaft 17 to allow a first moving member 5 and second moving member 13 to perform linear motion. At this time, the second moving member 13 secures movement of reciprocation 4 while obtaining a motion range of 2 through addition of movement of the first moving member 5 to movement moving on the member 5. The movement of the moving member 13 becomes equal to the total length of a transmission member 27 substantially. To the moving speed of the member 13, the moving speed of the member 5 is added, and a speedy linear motion is attained. As a result, a speedy linear motion with increased motion range is realized and the length of belt can be shortened.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a linear motion device used in a robot manibulator, a machine tool, etc.

(Prior Art) Conventionally, the one shown in FIG. 10, for example, is known as a representative linear motion VJ device used in robots, machine tools, and the like.

That is, the pair of linear guides 101, 101 have a moving portion N1.
03 is slidably supported, and the movable member 103 is a screw nut 107 screwed onto a screw shaft 105.
The screw shaft 105 is connected to the screw shaft 105 and is driven in forward or reverse rotation by a drive motor 109, so that linear movement of the moving member 103 can be obtained.

(Problems to be Solved by the Invention) As described above, the moving member 103 moves linearly along the linear guide 101, but the speed of movement depends on the center diameter of the ball in the screw nut 107 and the rotation of the screw shaft 105. Since the positioning speed is limited by the ON value determined by the speed, if the moving member 103 is applied as it is to the drive unit of a robot or machine tool, the positioning speed will be limited to the allowable range of the DN value, making it difficult to increase the speed. Further, since the operating range is equal to the length of the screw shaft 105, it becomes difficult to secure a wide operating range.

In this case, if the operating range is to be expanded, the screw shaft 105 must also be lengthened to accommodate the expanded operating range, resulting in an increase in the length of the entire device.

For this reason, in order to obtain an operating range longer than the length of the screw shaft, for example, as shown in FIG.
Below a fixed base 115 having a first movable member 113 that moves back and forth by rotation of 11, the first movable member 113
A movable base 117 is disposed that is connected to the movable base 117, and a second movable member 121 that moves back and forth along the linear guide 119 is provided within the movable base 117. First and second belts 123 and 125 are extended forward and backward from the second moving member 121, and the first belt 123 is folded back to the fixed base 127 via a slide 127 supported by the moving base 117.
It is connected to the front end of 15. The second belt 125 is similarly supported by the moving base 117! By connecting to the rear end of the folded fixed base 115 via the cable 129, as shown in FIG. Therefore, a method of doubling the minimum value of the second moving member 121 to 29 can be considered.

However, in the above means, the belt 123.12
5 must be placed on both sides of the device, driving in both directions will not be possible. Also, since the belts 123 and 125 are longer than necessary (the length of the belt is twice as long as the entire moving belt),
This increases the amount of expansion and contraction, making it difficult to maintain and manage stable accuracy over a long period of time.
This is also undesirable in terms of manufacturing and installation accuracy.

Therefore, the purpose of this invention is to provide a linear motion device that can expand the operating range and achieve rapid linear motion, as well as shorten the length of the belt and maintain stable accuracy over a long period of time. There is.

[Structure of the Invention] <Means for Solving the Problems> In order to achieve the above object, the present invention includes a base, a first movable member held by the base so as to be linearly movable, a rotating body rotatably supported by a first moving member and provided at at least two locations in the moving direction of the first moving member; At least two transmission members are hooked around, and the first movement is fixed to a portion of the transmission member that is approximately the longest distance from the portion fixed to the base, and is movable linearly in the movement direction. A linear movement vJg having a second moving member held by a member and a driving means for linearly driving the second moving member in the moving direction.
I set it to i.

(Function) According to such a linear movement VJ device, the first moving member moves linearly on the base, and the second moving member moves linearly on the first moving member, so that the range of motion can be increased. , and because these occur simultaneously due to the action of the transmission member, rapid linear motion can be obtained. Moreover, since the length of the transmission member is approximately equal to the entire moving circle, the amount of expansion and contraction is small, and stable accuracy is maintained over a long period of time.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings of FIGS. 1 to 3.

3 in the figure indicates a fixed base fixed to the base 1,
The fixed base 3 is formed into a substantially rectangular plate shape, and a first movable member 5 which is long in the front and rear directions is arranged above.

The first movable member 5 is dimensioned to fit within the width D of the fixed base 3, and a pair of upper and lower linear guide rails 7, 7, 9.9 are provided on both sides of the lower and upper surfaces of the first moving member 5, respectively. , the lower linear guide rail 7.9 has rail guide parts 11.11 fixed to the left and right sides of the fixed base 3.
It is slidably engaged with. The upper linear guide rails 7 and 9 are arranged on the left and right sides of the second moving member 13.
It is slidably engaged with the mounted rail guide portion 15.15. The second movable member 13 is shaped like a rectangular plate and has a width that is almost the same as the width D of the fixed base 3, and has a screw nut 19 screwed into the screw shaft 17 on the back side. is being closely watched.

The screw shaft 17 is rotatably supported at both ends by front and rear support brackets 21, 21 rising from the first moving member 5, and is driven by a drive motor 23 capable of forward and reverse rotation.

Thereby, the screw nut 19, that is, the second moving member 13, can move back and forth vJ (arrow A) by rotating the screw shaft 17 in the normal or reverse direction.

Furthermore, rotary bodies 25 and 25 formed in the shape of a booley are arranged in parallel to the first moving member 5 and are rotatably supported by rotary shafts 25a, 25a.

A belt-shaped transmission member 27 is looped around the front and rear rotating bodies 25.25, and is in a neutral position, that is, the fixed base 3.
When the second movable member 13 is positioned above (FIG. 1), a substantially intermediate portion of the upper side 27a of the transmission member 27 is coupled to the bottom surface of the second movable member 13. Further, a portion of the lower side 27b of the transmission member 27 approximately between Φ is connected to the fixed base 3. Therefore, by moving the transmission member 27, the first moving member 5 moves in the same direction via the rotating body 25, and at the same time, the second moving member 13 also moves in the same direction.

According to the linear motion device configured in this manner, the length is set to the dimension of the first moving member 5, and the width D is set within the width of the fixed base 3.

Next, the transmission member 27 is driven by the screw shaft 17 by rotating the driving motor 23 in the forward or reverse direction. As a result, the first moving member 5 and the second moving member 13 move linearly forward or backward. At this time, the second moving member 13 moves above the first moving member 5 as shown in FIG. 1
As a result of adding 3 11 D 2, a movement range of <21+ is obtained as shown in Figure 3, and the round trip is 41
The transfer ilJfl is secured. With the mechanism shown in FIG. 11, only half of the total length of the transmission member used can be obtained, but with the mechanism of the present invention, the moving member 13
The amount of movement is approximately equal to the total length of the transmission member. Therefore,
Expansion and shrinkage are suppressed, making it possible to maintain and manage stable accuracy over a long period of time.

Further, the moving speed of the second moving member 13 is increased by the moving speed of the first moving member 5, and a rapid linear movement is achieved.

4 and 5 show an embodiment in which support mechanisms 29, 29 are provided before and after the first moving member 13. FIG.

That is, a support leg 31 extends downward from the main body of the first moving member 13, and a support ring 33 that runs on the base 1 is provided on the support leg 31. Note that since the other structures are the same as those of the previous embodiment, the same reference numerals are given and detailed explanations are omitted.

Therefore, according to this embodiment, in addition to the effects of the previous embodiment, when the first moving member 13 moves back and forth from the neutral position, the support wheel 33 supports the front end or the rear end of the first moving member 5. Since the part is supported, stable movement is achieved without cantilevering.

In this case, as shown in FIGS. 6 and 7, a protruding guide surface 1a is formed on the upper surface of the base 1, and the front and rear rotating bodies 25, 25 are brought into direct contact with this guide surface 1a.
It is also possible to use the rotating body 25.25 itself as a support mechanism 29.29. At this time, it is desirable that the transmission member 27 is shifted so as to fit within the groove of the rotating body 25 so as not to come into direct contact with the guide surface 1a.

In addition, as shown in Fig. 8 and Fig. 9, a pair of linear guide rails 7, 7, 9, 9 are long in the front and rear.
It may also be supported movably along.

Note that the transmission member 27 is not limited to a belt type, and a chain or other means may be used.

[Effects of the Invention] As explained above, according to the linear motion device of the present invention, an expanded operating range and rapid linear motion can be obtained, and
By shortening the length of the belt, stable accuracy can be maintained over a long period of time.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway sectional view showing the linear motion device of the present invention, Fig. 2 is a front view of the same as above, Fig. 3 is an operation diagram, and Fig. 4 shows a support mechanism provided on the first moving member. FIG. 5 is a front view of the same as in FIG. 1; FIG. 6 is a cut-away side view of the same as in FIG. 4 showing a modified example of the support mechanism; FIG. 7 is a front view of the same as in FIG. 8 is a cutaway side view showing a slightly different modification of the support mechanism, FIG. 9 is a front view of the same, and FIG.
FIGS. 11 and 12 are explanatory diagrams showing conventional examples. 1... Base 3... Fixed base 5... First moving member 13... Second moving member 17... Screw shaft 23... Drive motor 25... Rotating body 27...・Transmission member

Claims (1)

[Claims] a base, and a first
a moving member, a rotating body rotatably supported by the first moving member and provided at at least two locations in the moving direction of the first moving member, and a rotating body having a substantially annular shape and a portion fixed to the base. a transmission member that extends around at least two of the rotating bodies; and a transmission member that is fixed to a portion of the transmission member that is approximately the longest distance from a portion that is fixed to the base, and is capable of linearly moving in the movement direction. A linear motion device comprising: a second moving member held by the first moving member; and a driving means for linearly driving the second moving member in the moving direction.