JP2000179638A - Feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a feeder heightened in feed screw supporting rigidity. SOLUTION: A feeder for driving a driven body 9 along a guide part provided at a feeder body 1 is provided with a screw shaft 6 rotatably supported at one end and the other end respectively to a first support 4 and a second support part 5 provided at the feeder body 1, and provided on its outer peripheral surface with a first thread groove 11 and a second thread groove 12 of different pitch from the first thread groove 11 thread-fastened to the driven body 9; a driving motor 8 rotatory-driving the screw shaft to move the driven body 9 along the guide part; and support members 16a, 16b thread-fastened to the second thread groove 12 of the screw shaft 6 and slid along the feeder body while supporting the screw shaft 6 by rotatory-driving the screw shaft 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feeder for driving a driven body screwed to a screw shaft by rotating the screw shaft.

[0002]

2. Description of the Related Art For example, when a driven body such as a hand of a robot apparatus or a table of a machine tool is linearly reciprocally driven, a screw shaft screwed with the driven body is rotatably supported by the apparatus body. The driven body is moved along a guide portion provided in the apparatus main body by rotating the screw shaft in the normal rotation direction or the reverse rotation direction by a driving source.

[0003] One end and the other end of the screw shaft are rotatably supported by a first support and a second support provided on the main body of the apparatus, and the driven body is screwed in the middle of the screw shaft. Have been combined. Therefore, since the middle part of the screw shaft is not supported at all except for the portion supported by the driven body, when the screw shaft is rotated at high speed due to the bending of the screw shaft, etc., In some cases, the screw shaft vibrates due to the resonance phenomenon between the rotation speed and the natural frequency of the screw shaft, which adversely affects the driven body and the support portion screwed to the screw shaft.

For this reason, the number of rotations of the screw shaft is reduced or the diameter of the screw shaft is increased. However, when the diameter of the screw shaft is increased, the moment of inertia increases. It is necessary to increase the capacity, and in that case, it is difficult to rotate the screw shaft at a high speed and increase the feed speed of the driven body.

[0005]

Therefore, by supporting other than the portion supported by the driven member in the middle of the screw shaft, vibration caused by the resonance phenomenon is suppressed even when the screw shaft is rotated at high speed. Feeding devices have been developed. As such a prior art, one disclosed in Japanese Patent Application Laid-Open No. 7-4490 has been proposed.

In the above prior art, three means are shown. A first means is to provide a pair of bearing brackets slidably on a linear guide on a ball screw shaft for linearly reciprocatingly driving the driven body, and to provide a driven body with a permanent magnet for attracting the bearing bracket, A stopper is provided in the middle of the linear guide.

When the driven body attracts one of the bearing brackets to the permanent magnet and moves to the center in the longitudinal direction of the ball screw shaft, the driven body is cut off by contacting the one of the bearing brackets with the stopper. The other bearing bracket can be moved by attracting the other bearing bracket to the permanent magnet.

Therefore, the ball screw shaft is supported not only by the driven body but also by the pair of bearing brackets, so that the support rigidity can be improved.

However, according to such a configuration,
When the driven body moves to the center of the feed ball screw, that is, the position where one of the bearing brackets hits the stopper, the driven body and a pair of bearing brackets gather at that position. Is supported, and other parts are unsupported. In other words, this is almost the same as when there is no pair of bearing brackets, and the support rigidity of the feed ball screw may be reduced.

In addition, since one bearing bracket is always located at the center of the ball screw, and the other bearing bracket is integral with the driven body, for example, when the driven body moves rightward, the ball screw is moved to the center. Although the support rigidity of the part and the right part is obtained, the left part is unsupported, which means that sufficient support rigidity cannot be obtained. That is, the support rigidity of the ball screw cannot be almost uniformly improved over the whole.

Therefore, the above-mentioned prior art shows that, as second and third means, a pair of bearing brackets provided on a feed ball screw are moved while maintaining a predetermined distance from a driven body. Have been. Thereby, the feed ball screw is supported evenly as a whole by the driven body and the pair of bearing brackets that are separated by a predetermined distance. Therefore, the support rigidity of the feed ball screw is smaller than that of the first means. Can be increased.

However, in the second means, in order to move the bearing bracket in conjunction with the movement of the driven body, a sub-feed ball screw with which the bearing bracket is screwed is provided. Is provided with a gear train for reducing the rotation of the feed ball screw at a predetermined ratio.

In the third means, a pantograph which expands and contracts in conjunction with movement of the driven body is provided, and a plurality of bearing brackets movably provided on a feed ball screw are connected to the pantograph. .

Therefore, according to the second and third means, parts such as a sub-feed ball screw, a gear train, a pantograph, etc., are used to make the bearing bracket interlock with the movement of the driven body while maintaining these intervals. This necessitates a complicated configuration and an increase in the size of the device.

An object of the present invention is to provide a feeder capable of increasing the support rigidity of a screw shaft without increasing the number of parts.

[0016]

According to a first aspect of the present invention, there is provided a feeder for driving a driven body along a guide portion provided on an apparatus main body, wherein the first support provided on the apparatus main body is provided. One end and the other end are rotatably supported by the portion and the second support, respectively, and the outer peripheral surface has a first screw groove screwed with the driven body and a pitch different from that of the first screw groove. A screw shaft on which a second screw groove is formed, a driving means for rotating the screw shaft to move the driven body along the guide portion, and a screw on the second screw groove of the screw shaft. And a support member that slides along the apparatus body while supporting the screw shaft by rotating the screw shaft.

Accordingly, since the support member is driven by the second screw groove formed on the screw shaft, a dedicated component for driving the support member is not required, and the second member is not required.
Since the pitch of the screw groove is different from that of the first screw groove for driving the driven body, the interval between the driven body and the support member is maintained, so that the support rigidity of the screw shaft can be ensured. it can.

According to a second aspect of the present invention, in the first aspect, the pitch of the second thread groove is formed to be 1 / N (where N is an integer) of the pitch of the first thread groove. On the screw shaft, (N-1) number of the support members are provided between one end of the driven body in the moving direction and the first support and between the other end and the second support. It is characterized by being provided.

Accordingly, the support member can be positioned at a predetermined position between one end of the driven body and the first support and between the other end and the second support. The support rigidity between one end and the other end of the driven body can be increased.

According to a third aspect of the present invention, in the first aspect of the present invention, the second screw groove is formed shallower than the first screw groove.

Accordingly, even if the supporting member is driven by the screw shaft, the second screw groove for that purpose can prevent the strength of the screw shaft from being reduced, and the driven member and the support member can be supported by one screw shaft. The members can be reliably driven.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

The feeder of the present invention shown in FIGS. 1 to 3 has an apparatus main body 1. The device main body 1 is formed with guide grooves 2 extending over the entire length in the longitudinal direction, leaving side wall portions 3 at both ends in the width direction, and opening to the upper surface of the device main body 1.

A first support portion 4 is provided at one longitudinal end of the guide groove 2, and a second support portion 5 is provided at the other end. As shown in FIG. 1, support holes 4a and 5a are formed in these support portions 4 and 5, and one end and the other end of the screw shaft 6 are rotated by bearings 4b and 5b in each of the support holes 4a and 5a. It is freely supported.

A driving motor 8 as driving means is connected to one end of the screw shaft 6 via a joint 7. Therefore, when the drive motor 8 is operated, the screw shaft 6 can be rotationally driven.

The first screw groove 1 is provided on the outer peripheral surface of the screw shaft 6.
The first and second thread grooves 12 are formed. The second screw groove 12 has a smaller pitch than the first screw groove 11, that is, a half pitch in this embodiment, and has a depth of about half the depth of the first screw groove 11. Have been.

A driven body 9 is screwed to the screw shaft 6. That is, the driven body 9 is the first screw groove 1 of the screw shaft 6.
1 screwed. A slide member 13 having a concave groove 13a is provided on the lower surface on both sides in the width direction of the driven body 9,
These slide members 13 have their concave grooves 13a slidably engaged with a pair of guide rails 14 laid on the bottom of the guide groove 2.

Therefore, if the drive motor 8 is operated to rotate the screw shaft 6 in the normal rotation direction or the reverse rotation direction, the driven body 9 is rotated in the first screw groove 11 of the screw shaft 6.
Thereby, reciprocation can be performed along the guide rail 14.

The second screw groove 12 of the screw shaft 6 is provided between one end of the driven body 9 in the traveling direction and the first support portion 4 and between the other end and the second support portion 5. A block-shaped first support member 16a and a second support member 16b are screwed into substantially the center, respectively.

The lower end surfaces of the support members 6a and 16b are slidably joined to the bottom surface of the guide groove 2 of the apparatus main body 1. Thus, when the screw shaft 6 is driven to rotate, the support members 16a and 16b are reciprocated along the guide groove 2 by the second screw grooves 12 of the screw shaft 6. .

Next, the operation of the feeder having the above configuration will be described.

As shown in FIG. 1, when the driven body 9 is located substantially at the center of the apparatus main body 1 in the longitudinal direction, the first support member 16a is connected to one end of the driven body 9 and the first supporting portion 4 And the second support member 5 is located substantially at the center between the other end of the driven body 9 and the second support portion 5.

In this state, when the drive motor 8 is operated to rotate the screw shaft 6 in, for example, a normal rotation direction, the driven body 9 screwed into the first screw groove 11 of the screw shaft 6 is rotated. It is driven in the forward direction indicated by arrow A in the figure. At the same time, the first and second support members 16a and 16b screwed into the second second screw grooves 12 of the screw shaft 6 are driven in the same direction as the arrow A.

The pitch of the second screw groove 12 into which the first and second support members 16a and 16b are screwed is set to substantially half the pitch of the first screw groove 11 into which the driven body 9 is screwed. ing. Therefore, as shown by a chain line in FIG.
Is driven in the direction of arrow A by a distance of dimension X, the first and second support members 16a and 16b
Distance.

Therefore, even if the driven body 9 is driven,
The first support member 16a is located at the center between one end of the driven body 9 and the first support portion 4, and the second support member 16b is located at the other end of the driven body 9 and the second support portion 5. Will be located in the middle between.

That is, even if the driven body 9 is driven, the first
Of the screw shaft 6 between the driven body 9 and the first support part 4 and between the driven body 9 and the second support part 5 Since the screw shaft 6 supports almost the center of the portion, the screw shaft 6 is supported by each support member 16a,
By 6b, it is supported in a state where the supporting rigidity is the highest.

Each of the support members 16a and 16b is screwed into a second screw groove 12 formed in the screw shaft 6. Therefore, since the supporting members 16a and 16b are driven in conjunction with the driving of the driven body 9, there is no need for a dedicated component. Therefore, an increase in the number of components and an increase in the size of the apparatus are not caused. .

The second screw groove 12 is the first screw groove 11
About half the depth of Therefore, screw shaft 6
Even if a second screw groove 12 for driving the supporting members 16a and 16b is formed on the screw shaft 6, the second screw groove 12
Does not lower the strength of the steel.

Further, since the depths of the first screw groove 11 and the second screw groove 12 are different, the driven body 9 and the supporting members 16a, 16b can be reliably formed by each screw groove of one screw shaft 6. Can be driven.

In the above embodiment, the portion between one end of the driven member 9 and the first support portion 4 and the other end are connected to the second support portion 5.
And one supporting member 16a, 16b
However, when the screw shaft 6 is elongated, a plurality of support members may be provided at the portions between the above.

FIG. 4 is a plan view showing a second embodiment of the present invention in which two support members 16a, 16a and 16b, 16b are provided at the portions between the above-mentioned portions. 9, the pitch of the second screw grooves 12 formed on the screw shaft 6 is one third of the pitch of the first screw grooves 11 in order to keep the distance between each pair of support members constant according to the movement of the first screw groove 11. Is set to

Accordingly, each pair of support members 16a, 16a,
Since the distance between 16a, 16b, and 16b is kept constant even when the driven body 9 is driven, the pair of support members may be too close or too far apart to deteriorate the support state of the screw shaft 6. Is prevented.

The number of support members provided at a portion between the driven body and each of the first support portion and the second support portion may be three or more. Can be changed according to the number of support members.

That is, assuming that the number of support members provided in the above-mentioned portion is (N-1), the pitch of the first screw groove is set to 1 / N of the pitch of the first screw groove. If
Even if the driven member is driven by driving the screw shaft, the distance between the support members does not change, so that the support state of the screw shaft by these support members is not impaired.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, the driven body 9 and the supporting members 16a,
A configuration for slidably guiding 16b is different from that of the first embodiment. That is, in this embodiment, the support member 16 screwed into the second screw groove 12 of the screw shaft 6
The lengths a and 16b of the guide groove 2 are substantially the same as the width of the guide groove 2.
Are guided by the inner surfaces of both sides.

The driven body 9 screwed into the first screw groove 11 of the screw shaft 6 has a groove 1 at the center of the lower surface in the width direction.
One slide member 13 having 3a is provided. In the guide groove 2 of the apparatus main body 1, one guide rail 14 is laid at the center of the bottom in the width direction over the entire length in the longitudinal direction. The slide member 13 slidably engages the groove 13a with the guide rail.

Accordingly, even in the feeder having such a configuration, the support rigidity of the screw shaft 6 can be reliably increased by the support members 16a and 16b, as in the first embodiment.

In the third embodiment, the number of support members provided on both sides of the driven body is not limited.
Just as in the first embodiment, one or more may be used.

In the first embodiment, the pair of supporting portions may be formed integrally with the apparatus main body, or may be formed separately and attached and fixed to the apparatus main body.

[0050]

According to the first aspect of the present invention, a first screw groove for driving a driven body and a second screw for driving a support member at a different pitch from the first screw groove are provided on the screw shaft. A groove was formed.

Therefore, since the support member is driven by the second screw groove formed on the screw shaft, a dedicated component for driving the support member is not required, and the second screw groove is driven by the second screw groove. Since the pitch is different from that of the first thread groove for driving the body, the support member can always be located substantially at the center between the driven body and the driven body even when the driven body is moved. Thus, the support rigidity of the screw shaft can be reliably ensured.

According to the second aspect of the present invention, the supporting member is provided between one end of the driven body and the first supporting portion and between the other end and the second supporting portion.
And the number corresponding to the pitch of the second thread groove.

Therefore, the plurality of support members can be positioned at substantially equal intervals between the driven member and the support portion regardless of driving of the driven member. The support rigidity of the other end portion can be reliably increased, and this is particularly effective when the screw shaft is elongated.

According to the third aspect of the present invention, since the second screw groove is formed shallower than the first screw groove, even if the support member is driven by the screw shaft, the second screw groove for that purpose is provided. Not only can prevent the strength of the screw shaft from being reduced, but also the driving of the driven body by the first screw groove and the driving of the support member by the second screw groove can be reliably performed by one screw shaft. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view of a feeder according to a first embodiment of the present invention.

FIG. 2 is a side view of the same sectional view.

FIG. 3 is a longitudinal sectional view of a driven body.

FIG. 4 is a plan view of a feeder according to a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a feeder according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body 4 ... 1st support part 5 ... 2nd support part 8 ... Drive motor (drive means) 9 ... Driven body 11 ... 1st screw groove 12 ... 2nd screw groove 16a, 16b ... Support Element

Claims (3)

[Claims] 1. A feed device for driving a driven body along a guide portion provided on an apparatus main body, wherein the first support portion and the second support portion provided on the device main body have one end portions. The other end is rotatably supported, and the outer peripheral surface is provided with a first screw groove screwed with the driven body and a second screw groove having a pitch different from that of the first screw groove. Driving means for rotating the screw shaft to move the driven body along the guide portion; and being screwed into the second screw groove of the screw shaft to rotate the screw shaft. And a support member that slides along the apparatus body while supporting the screw shaft. 2. The pitch of the second screw groove is formed to be 1 / N (where N is an integer) of the pitch of the first screw groove, and the screw shaft has a moving direction of the driven body. The number of (N-1) number of the support members provided between the one end and the first support and between the other end and the second support, respectively. Feeding device as described. 3. The feed device according to claim 1, wherein the second screw groove is formed shallower than the first screw groove.