JPH0529829Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to a dustproof device for a Cartesian coordinate robot, and more specifically, a dustproof sheet that covers the opening surface of a base casing that supports a slide base in a reciprocating manner. The present invention relates to a dust prevention device for an orthogonal coordinate robot in which the dust is guided into the slide base by guide rolls.

<Prior art and problems to be solved by the invention> Cartesian coordinate robots, which can easily cope with increases and decreases in the number of axes, have been provided as a type of industrial robot.

This Cartesian coordinate robot is capable of reciprocating the slide base with at least a part of it protruding from a base casing with one side open. For example, a ball screw provided inside the base casing is inserted into a ball screw nut of the slide base, and the slide base can be moved to a desired position by controlling the direction and amount of rotation of the ball screw. Also, a dustproof device is provided to prevent dust from entering the inside of the base casing that houses the ball screw. As a specific configuration of this dustproof device, a guide roll is provided inside the slide base, and a part of a dustproof sheet that is tensioned to cover the opening of the base casing is bypassed by the guide roll, thereby allowing the ball screw to transmit the driving force to the slide base well and achieving good dustproof performance by the dustproof sheet (see Japanese Utility Model Publication No. 62-174893 and U.S. Patent Specification No. 4,545,290).

However, in the dustproof device with the above configuration, the guide roll follows the reciprocating movement of the slide base by rotatably supporting both ends of the rotating shaft formed integrally with the roll body at a predetermined position on the slide base. However, there are problems in that the wear at both ends of the rotating shaft becomes significant and the height of the slide base increases.

To explain in more detail, if you adopt a configuration in which both ends of the rotating shaft are inserted directly into holes provided in the slide base, all you need to do is increase the height of the slide base to correspond to the diameter of the roll body, and the slide Although the height of the base can be minimized, due to the tension of the dustproof sheet, a fairly large load is applied to the guide roll, and the entire load is rotated relative to the slide base. Since the shaft has to be supported only at both ends, the wear in these parts increases significantly, shortening its life. Furthermore, since the positional accuracy of the holes that support both ends of the rotating shaft is not very high, there is a high possibility that the rotating shaft will be tilted to some extent, and in such a situation, local wear becomes especially significant. This results in a significantly shortened lifespan.

In order to solve this problem, it is possible to install bearings on the slide base and use the bearings to support both ends of the rotating shaft. Because the height of the slide base becomes higher, the height of the slide base becomes higher. Regarding the height of the slide base mentioned above, in Cartesian coordinate robots, the base casing is fixed on a predetermined base, and the slide base, which reciprocates with respect to this base, is used as a new base. Since the number of axes is increased by connecting base casings or slide bases in different axial directions, the orthogonal coordinate robot as a whole becomes considerably larger, which becomes a problem that cannot be ignored. It is. Furthermore, the provision of bearings also increases costs.

<Purpose of the invention> This invention was made in view of the above-mentioned problems, and it is possible to simplify the configuration, lower the height of the slide base, and extend its life. The purpose of the present invention is to provide a dust prevention device for a Cartesian coordinate robot that can be used in an orthogonal coordinate system.

<Means for solving the problem> In order to achieve the above object, the dust prevention device in the orthogonal coordinate robot of this invention is designed to bypass the dust prevention sheet covering the opening surface of the base casing and guide it into the slide base. The guide roll includes a fixed shaft horizontally suspended on a slide base, and an elongated cylindrical body rotatably supported by the fixed shaft.

However, the above-mentioned fixed shaft only needs to have a certain degree of bending strength, and a round shaft made of iron or the like can be used. Further, as the above-mentioned long cylinder, one made of any material can be used, but one made of polyethylene, fluororesin, etc. can exhibit good lubrication performance. Therefore, it is preferable. Further, the dust-proof sheet may be one having sufficient tensile strength and flexibility, such as one made of metal formed into a thin plate, or one made by laminating a plurality of synthetic resin sheets and integrating them.

<Function> With the dustproof device having the above configuration, when the slide base is reciprocated via the driving force transmission mechanism housed in the base casing, the dust is diverted by the guide roll and guided into the slide base. The detour point of the dustproof sheet moves following the reciprocating motion of the slide base, and the guide roll rotates following the movement of the detour point. Since the rotation of the guide roll is achieved by the rotation of the elongated cylindrical body around the fixed shaft that is suspended horizontally on the slide base, wear does not occur at the connection between the fixed shaft and the slide base. In addition, since the load acts between the long cylindrical body and the fixed shaft in a state that is distributed over the entire length of the long cylindrical body, wear can be significantly reduced. In addition, even if the difference between the outer diameter of the fixed shaft and the inner diameter of the elongated cylindrical body is large, the elongated cylindrical body can be rotated smoothly, and the reciprocating movement of the slide base can be made smooth.

<Examples> Hereinafter, examples will be described in detail with reference to the accompanying drawings showing examples.

FIG. 3 is a vertical sectional view showing only one axis of a Cartesian coordinate robot incorporating the dust prevention device of this invention.

A ball screw 2 and a pair of guide rails 3 are housed inside a base casing 1 having a predetermined length, and both ends of a dustproof sheet 4 are fixed so as to cover the opening surface of the base casing 1. . A motor 5 for rotationally driving the ball screw 2 is provided at a predetermined position of the base casing 1. Further, it has a ball screw nut 6a that is screwed into the ball screw 2, and a guide rail 3.
A part of the slide base 6 having a linear slider 6b that engages with the slider 6b protrudes from the base casing 1.

FIG. 1 is an enlarged central vertical sectional view showing the main parts of the dustproof device, and shows a dustproof sheet insertion hole 6c in a predetermined position of the slide base 6 protruding from the base casing 1.
are formed, and four guide rolls 7 are provided at predetermined positions of the dustproof sheet insertion hole 6c. The guide roll 7 located at the end is provided at almost the same height as the opening surface of the base casing 1, and the remaining guide rolls 7 are located outward from the base casing 1. It is set up to do so. Therefore, the dustproof sheet 4 is wound around the guide roll 7 located at the end from below, and is wound around the remaining guide rolls 7 from above.

FIG. 2 is a longitudinal sectional view showing the configuration of the guide roll, in which insertion holes 7a are formed at predetermined positions of the slide base 6 so as to face each other, and a fixed shaft 7b is horizontally suspended between the insertion holes. There is. A long cylindrical body 7c having an inner diameter larger than the outer diameter of the fixed shaft 7b is loosely inserted into the fixed shaft 7b. Also, as is clear from Fig. 2, the width of the dustproof sheet 4 is
It is set smaller than the width of the dustproof sheet insertion hole 6c and larger than the opening width of the base casing 1.

The operation of the orthogonal coordinate robot having the above configuration is as follows.

When the motor 5 rotates the ball screw 2 by an arbitrary angle in either direction, the ball screw nut 6a screwed with the ball screw 2 converts it into a translational force, so that the slide base 6 can rotate at an arbitrary angle. Move to position.

In this case, the dustproof sheet 4 is detoured only between the guide rolls 7, so it continues to cover the opening surface of the base casing 1 and reliably prevents dust from entering. be able to. Furthermore, when the slide base 6 moves, the detour points of the dustproof sheet 4 move sequentially, and each guide roll 7 is subjected to a load due to the tension of the dustproof sheet 4. However, since the elongated cylindrical body 7c is rotatably loosely inserted into the fixed shaft 7b,
The load-bearing area becomes wider, preventing the load from being concentrated in one area, and significantly improving durability. Further, as is clear from the above explanation, it is preferable that the outer diameter of the fixed shaft 7b and the inner diameter of the elongated cylinder 7c are approximate, but even if they are not necessarily approximate, they may change due to movement of the detour point. Long cylindrical body 7
This allows for smooth rotation. Therefore, the inconvenience that the load for moving the slide base 6 becomes particularly large does not occur.

As a result, the dimensional accuracy required for the guide roll can be lowered without reducing the dustproof effect, and the configuration of the guide roll can be simplified, significantly improving work efficiency such as assembly and maintenance. can be done. Furthermore, since there is no need to provide a bearing, the height of the slide base 6 can be prevented from becoming higher than necessary, and the orthogonal coordinate robot can be downsized.

Note that this invention is not limited to the above-mentioned embodiment, and for example, the number of guide rolls 7 can be increased or decreased, and the slide base 6 can be reciprocated by a driving force transmission mechanism other than a ball screw. In addition, various design changes can be made without changing the gist of the invention.

<Effects of the invention> As described above, in this invention, the guide roll for bypassing the dustproof sheet is composed of a fixed shaft and a long cylindrical body loosely inserted into the fixed shaft, which improves the dustproof effect and the slide base. The configuration can be simplified without reducing the mobility of the
By reducing the surface pressure per unit performance, durability can be significantly improved, and the required dimensional accuracy can be lowered, and the workability of assembly and maintenance can be improved. It has the desired effect.

[Brief explanation of drawings]

Figure 1 is an enlarged central vertical sectional view showing the main parts of the dust prevention device, Figure 2 is a vertical sectional view showing the configuration of the guide roll, and Figure 3 is one axis of a Cartesian coordinate robot incorporating the dust prevention device of this invention. FIG. 1...Base casing, 2...Ball screw, 4
...Dustproof sheet, 6...Slide base, 6a...
...Ball screw nut, 7...Guide roll, 7b
...Fixed shaft, 7c...Long cylindrical body.

Claims (1)

[Scope of utility model registration request] A slide base 6 is provided to protrude from the opening surface of the base casing 1, and the slide base 6 is reciprocated by the driving force transmission mechanism 2, 6a housed in the base casing 1. In the orthogonal coordinate robot in which the dustproof sheet 4 covering the opening surface of the base casing 1 is detoured by a guide roll 7 and guided into the slide base 6, the guide roll 7 is connected to a fixed shaft horizontally suspended on the slide base 6. 7b, and a long cylindrical body 7c rotatably supported by a fixed shaft 7b.