JPH0674738A - Laser beam protector for measuring apparatus - Google Patents

Abstract

PURPOSE:To reduce manufacturing cost of laser beam protector, as compared with a protector employing a bellows, by protecting a laser beam by means of a fixed side tubular body and a movable side tubular body and to increase allowable displacement in the direction perpendicular to the moving direction of a moving body by placing spherical bearings at the joints of each tubular body and an illuminator and the light receiving unit side. CONSTITUTION:Fixed side and movable side tubular bodies 11, 17 are disposed covering the optical path of laser beam over the side of fixed laser beam irradiator 5 and a light receiving unit 6 fixed on a straight advancing body 3 side. One end part of the movable side tubular body 17 and the laser beam irradiator 5 are held rockingly and slidingly along the optical path through a spherical bearing 14 while the other end part of the movable side tubular body 17 and a holding tubular body 15 on the light receiving unit 6 side are held through a spherical bearing 16. Furthermore, enclosed members 18, 19 for interrupting communication with the outside are disposed at the holding parts of the tubular bodies 11, 17 on the irradiator side and the light receiving unit side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protector for protecting a laser beam, which serves as a reference when measuring the degree of rectilinear movement of a rectilinear moving body in a moving mechanism such as a machine tool or measuring machine with a very high accuracy. It is about.

[0002]

2. Description of the Related Art Conventionally, such a high precision machine tool,
A laser beam is used as a reference for measuring the degree of straightness of a measuring device for measuring the degree of straightness of a straight moving body in a moving mechanism such as a measuring machine.

That is, a laser beam irradiator is arranged at a predetermined position, and a laser beam light receiver is provided on the side of the rectilinear moving body. The straightness of the body is measured.

In the above measuring device, in order to improve the measurement accuracy, the optical path through which the laser beam passes is kept in a vacuum, and the measurement error due to the presence of air, for example, the influence of air fluctuation due to temperature change, etc. Therefore, the optical path of the laser beam is covered with a metal bellows type cover.

[0005]

However, according to the above-mentioned conventional structure, the metal bellows type cover is used as the cover for protecting the optical path of the laser beam.
There is a problem that its manufacturing cost is high,
There is a problem that the degree of freedom with respect to the displacement in the direction perpendicular to the expansion and contraction direction is small.

Therefore, an object of the present invention is to provide a laser beam protector in a measuring instrument which can solve the above problems.

[0007]

In order to solve the above-mentioned problems, the laser beam protector in the measuring instrument of the present invention comprises:
A laser beam protector in a measuring instrument that measures the degree of straightness of a rectilinear moving body using a laser beam, and extends between the laser beam irradiator side that is fixedly arranged and the photoreceiver attached to the rectilinear moving body side. A cylindrical body that covers the optical path of the laser beam, and one end of this cylindrical body is inserted and held on the side of the illuminator or the light receiver through a spherical bearing so that it can slide and swing along the optical path. In addition, the other end of the tubular body is held on the side of the light receiver or the irradiator via a spherical bearing, and the holding portion between the tubular body and the irradiator side and between the tubular body and the light receiver side. The holding portion is provided with a sealing member for shutting off from the outside.

[0008]

According to the above construction, since the cylindrical body for protecting the laser beam is slidably provided on the irradiator or the light receiver side, it can smoothly follow the movement of the rectilinear moving body, Since a spherical bearing is provided in each holding part that is a connection point between the cylindrical body and the irradiator side and the cylindrical body and the light receiver side, the allowable movement displacement amount in the direction orthogonal to the moving direction of the moving body Can be large.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, reference numeral 1 denotes a moving mechanism portion in a highly accurate device such as a machine tool or a measuring machine, which is a guide member 2
And a linearly moving body (hereinafter, simply referred to as a moving body) 3 guided by the guide member 2 so as to be movable along a straight line, and a measuring device 4 for measuring the straightness of the moving body 3. Is provided. In addition, the moving body 3
For example, processing tools, measuring tools, etc. are attached. 3 The measuring device 4 uses a laser beam, has a laser beam irradiator 5 and a laser beam light receiver 6, and vacuumizes an optical path that is a passage path of the laser beam to generate a laser beam. A protector 7 is provided to maintain the straightness of the light beam itself.

The protector 7 has a fixed side cylinder 11 having a through hole 12 through which the laser beam irradiator 5 is attached at one end and through which a laser beam can pass, and a fixed side cylinder at one end. A slide member (for example,
A light receiver 6 which is held slidably and swingably in an arbitrary direction via a linear bearing) 13 and a spherical bearing 14 and has the other end provided on the side surface of the moving body 3.
A movable-side cylinder (cylindrical body) 17, which is held so as to be swingable in an arbitrary direction via a spherical bearing 16 on the side of the holding cylinder 15 attached so as to cover the movable-side cylinder 17. Of the movable side tubular body 17, the fixed side tubular body 11, the other end of the movable side tubular body 17, and the holding tubular body 15.
It is composed of movable side and fixed side sealing members 18 and 19 which are respectively provided at connection points with.

The movable side sealing member 18 is the fixed side cylinder body 1.
The ring body 21 inserted into the inlet-side large-diameter portion 12a of the through hole 12 of No. 1 and the grease 22 that is filled in the gap between the ring body 21 and the movable-side tubular body 17 and shuts off from the outside.
And oil seals 23 inserted in the front and rear portions of the gap to prevent the grease 22 from flowing out.

The fixed side sealing member 19 is a tubular cover made of an elastic material such as rubber, and has the other end of the movable side tubular body 17 and the guide tubular portion 15a of the holding tubular body 15.
It is installed over and.

On the fixed side cylinder body 11 side, a joint 31 for connecting a vacuum pump and a joint 32 for connecting a vacuum gauge are provided for sucking air in the passage of the laser beam, that is, the optical path. .

Further, the through hole 12 in the fixed side cylinder body 11
The optical path of the laser beam is formed by the hole 17a of the movable side cylinder 17. In the above structure, first, the vacuum pump sucks the air in the through hole 12 of the fixed-side cylinder 11 and the hole 17a of the movable-side cylinder 17 to keep the optical path of the laser beam in a vacuum state.

In this state, when the movable body 3 moves back and forth, one end side of the movable side cylinder 17 is inserted through the slide member 13 into the through hole 12 of the fixed side cylinder 11 along the optical path. Will be guided to move. At the time of this movement, the fixed side tubular body 11 is maintained in a sealed state with the outside by the grease 22, and, of course, the fixed side sealing member 19 seals the closed state with the holding tubular body 15 on the light receiver 6 side. Has been maintained.

When, for example, the movable body 3 is displaced in the direction perpendicular to the optical path, both ends of the movable side cylinder 17 are held via the spherical bearings 14 and 16, respectively. Can follow its displacement without hindrance. Of course, also in this case, the grease 22 and the fixed-side sealing member 19 maintain the sealed state with the outside.

The gap between the outer peripheral surface of the other end of the movable side cylinder 17 and the inner peripheral surface of the holding cylinder 15 is equal to that of the movable body 3.
Is large enough not to cause a problem even if the is displaced in the right angle direction.

Since the laser beam is protected by the fixed-side cylinder and the movable-side cylinder in this manner, unlike the conventional case using the bellows, the manufacturing cost thereof is low, and each cylinder is different. Since the spherical bearing is provided in the holding portion, which is a connection point between the body and the irradiator and the light receiver side, the allowable displacement amount in the direction orthogonal to the moving direction of the moving body becomes large.

In the above embodiment, grease was used as the sealing material for sealing with the outside, but the grease is not limited to this. By the way, in the above embodiment, the laser beam irradiator was attached to the fixed side cylinder and the light receiver was arranged on the movable side cylinder side, but in some cases, the irradiator was attached to the movable side cylinder and the light receiver was installed. You may make it arrange | position on the fixed side cylinder body side.

[0020]

As described above, according to the structure of the present invention, since the laser beam is protected by the cylindrical body, it is possible to prevent
Unlike the one using a bellows, its manufacturing cost is low, and spherical bearings are provided in the holding parts, which are the connection points between the tubular body and the irradiator and light receiver side, so It is possible to increase the movement allowable displacement amount in the direction orthogonal to the movement direction.

[Brief description of drawings]

FIG. 1 is a partially cutaway overall plan view showing the configuration of a laser beam protector in one embodiment of the present invention.

[Explanation of symbols]

 3 Straight-moving body 4 Measuring device 5 Irradiator 6 Light receiver 7 Protective body 7a Hole portion 11 Fixed side cylinder 12 Through hole 13 Slide member 14 Spherical bearing 15 Holding cylinder 16 Spherical bearing 17 Movable side cylinder 18 Movable side sealing member 19 Fixed side sealing member 22 Grease 23 Oil seal

Claims (1)

[Claims] 1. A protector for a laser beam in a measuring instrument for measuring the straightness of a rectilinear moving body using a laser beam, which is attached to a fixedly arranged laser beam irradiator side and a rectilinear moving body side. A cylindrical body covering the optical path of the laser beam is arranged over the light receiver, and one end side of this cylindrical body is slid and shaken along the optical path to the irradiator or the light receiver side through a spherical bearing. While movably inserted and held, the other end of the tubular body is held on the side of the light receiver or the illuminator via a spherical bearing, and the holding portion between the tubular body and the illuminator side and the tubular body. A protective body for a laser beam in a measuring instrument, characterized in that a sealing member for shutting off from the outside is provided in each of the holding portions on the side of the light receiver.