JPS63100314A - Scale device - Google Patents

Abstract

PURPOSE:To perform temperature control over a scale base with fluid by providing a scale device with a fluid passage where the fluid which controls the temperature of the scale base flows. CONSTITUTION:The fluid which is brought under temperature control to specific temperature is supplied from a fluid intake 14a, passed through the fluid passage 13, and discharged from a fluid outlet 14b. Consequently, the scale substrate 11 is heated or cooled to the fluid temperature and displaced thermally as specified. When the scale device is used principally to correct the thermal displacement of a mechanical structure, the fluid which is controlled to constant temperature is supplied to maintain the quantity of thermal displacement of the scale base 11 at a specific value. In another way, the temperature of the fluid is controlled in proportion to the temperature of the mechanical structure and supplied so as to correspond to the thermal displacement of the mechanical structure. The control over the fluid temperature like this is easily performed by using a fluid temperature controller equipped with a heater, a thermistor, etc.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a scale device used in machine tools, coordinate measuring machines, digitizers, etc., to measure or detect the position of a moving object. In particular, the present invention relates to a scale device capable of controlling thermal displacement of a scale base into which scale information is input.

(Prior Art) Scale devices such as linear scales are used in machine tools, three-dimensional measuring machines, digitizers, and the like to measure or detect the position of a moving object.

The scale device is equipped with a magnetic scale base which is manually operated as a magnetic memory for scale information, or an optical scale base into which optically readable information is input, and this scale base is made of a rod-shaped member. There are some types that are made of solid wood or thin plate-like members. Such a scale base is attached to the casing by being held within the casing or stretched and held on the surface of the casing, and can be attached to the machine structure by fixing the casing to a machine structure such as a machine tool. is being done.

(Problem to be solved by the invention) Some scale bases are installed so that they undergo the same thermal displacement as mechanical structures, but most are made of materials with a smaller coefficient of thermal expansion than mechanical structures. , the thermal displacement is different from that of the mechanical structure.

Therefore, when machining is performed using a mechanical structure that is not installed in a constant temperature room, the mechanical structure undergoes complex thermal displacement due to changes in the temperature of the environment, and the scale base also undergoes its own thermal displacement. When correcting thermal displacement of mechanical structures, it is difficult to process the workpiece with high precision or measure the shape and dimensions of the object with high precision.

The present invention has been made in consideration of these points,
It is an object of the present invention to provide a scale device that can control the amount of thermal displacement of a scale base based on the temperature environment of a place where a mechanical structure is installed, the shape of the mechanical structure, etc.

[Structure of the invention]

(Means for Solving Problems) The present invention provides a scale device including a scale base into which scale information is input, and a casing to which the scale base is attached and held. It is characterized by providing a fluid passage through which a fluid for controlling the temperature of the fluid flows.

(Function) According to the present invention, by flowing a temperature-controlled fluid through the fluid passage, the temperature of the scale base can be directly or indirectly controlled and the amount of thermal displacement of the scale base can be maintained at a desired value. can.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of the present invention. In the figure, reference numeral 11 denotes a scale base, into which scale information is input in the form of a magnetic memory by coating or plating a magnetic medium, and is formed from a rod-shaped member. This scale base 11 is disposed within a hollow casing 12, and is held by inserting both ends into casing holders 12a and 12b.

The scale base 11 has a hollow shape, and has a fluid passage 13 formed therein through which a fluid such as gas or liquid passes. This fluid passage 13 includes a casing holder 12a,
It communicates with a fluid inlet 14a and a fluid outlet 14b, respectively provided in 12b.

Next, the operation of this embodiment having such a configuration will be explained.

A fluid whose temperature is controlled to a predetermined temperature is introduced from the fluid inlet 14a, and is passed through the fluid passage 13 to the fluid outlet 14b.
discharge from. Thereby, the scale base 11 is heated or cooled by the fluid temperature, and undergoes a predetermined thermal displacement.

When the scale device is mainly used to correct thermal displacement of a mechanical structure, a fluid controlled at a constant temperature is passed through the scale device to maintain the amount of thermal displacement of the scale base 11 at a predetermined value. Alternatively, in order to correspond to the thermal displacement of the mechanical structure, the temperature of the fluid is controlled in proportion to the temperature of the mechanical structure and the fluid is circulated.

Such fluid temperature control can be easily performed using a fluid temperature control device that includes a heater, a thermistor, or the like.

As described above, according to this embodiment, it is possible to cause the scale base body to undergo the most desirable thermal displacement depending on its purpose of use and use environment, and it is possible to improve machining accuracy and 7111j determination accuracy.

FIG. 2 is a sectional view showing a second embodiment of the invention. In this embodiment, a thin plate-like member is used as the scale base 21, and a magnetic memory or optical memory for scale information is physically or chemically plated on the surface of this thin plate-like member. The scale base 21 is fixedly attached to the surface of a mounting casing 22, which is constructed by connecting a plurality of blocks 22a, 22b, and 22c in series, with both ends being pulled. Inside the mount casing 22, there is a fluid passage 2 parallel to the scale base 21.
3 is formed, and a fluid inlet 24a and a fluid outlet 24b are provided at both ends of this fluid passage 23.

In this embodiment, temperature-controlled fluid is introduced into the fluid passage 23 in the mount casing 22 in the same manner as in the embodiment described above, and by passing through the fluid passage 23,
The temperature of the mount casing 22 is controlled to a predetermined temperature. Thereby, the temperature of the scale base 21 is indirectly controlled by the fluid, and a predetermined thermal displacement can be obtained.

FIG. 3 is a perspective view including a partially broken part showing a third embodiment of the present invention. In this embodiment, the scale base 31
The scale base 31 is covered with a hollow casing 32 to protect it from external coughs, cutting agents, etc. The scale base 31 is
It is disposed inside the hollow casing 32 by being fixed perpendicularly to the inner wall of the casing, and a fluid inlet 34a1 and a fluid outlet 34b are provided at both ends of the hollow casing 32, respectively.

In this embodiment, a temperature-controlled fluid is introduced into the hollow casing 32, and the scale base 31 disposed therein is controlled to a predetermined temperature.

FIG. 4 is a sectional view showing a modification of the embodiment of the invention shown in FIG. In this embodiment, a scale base 41 made of a thin plate-like member is mounted inside the hollow casing 42 via a mounting member 43 provided inside the hollow casing 42. The mounting member 43 is composed of two plate-like members, and holds the scale base 41 by sandwiching the scale base 41 from both sides. Also,
A groove 4 is partially formed in the part where the scale base 41 is held.
4 is provided, thereby forming a passage through which fluid flows.

In this embodiment, the scale base 41 is attached to the mounting member 4.
Since the scale base 41, the hollow casing 42, and the mounting member 43 have different coefficients of thermal expansion, the scale base 41 can be independently thermally displaced. Further, by passing a temperature-controlled fluid through the fluid passage formed by the groove 44, the amount of thermal displacement of the scale base 41 can be controlled to an appropriate maximum. Note that reference numeral 45 is a mounting hole for mounting this scale device to a mechanical structure or the like.

〔Effect of the invention〕

As described above, according to the present invention, the temperature of the scale base disposed in the scale device can be directly or indirectly controlled using a temperature-controlled fluid. Thereby, the amount of thermal displacement of the scale base can be suitably controlled depending on the temperature environment of the place where the mechanical structure is installed, the shape of the mechanical structure, the type of workpiece to be processed, etc.

By using the scale device according to the present invention in machine tools, measuring machines, etc., it is possible to improve the processing accuracy and measurement accuracy of these machines.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of a scale device according to the invention, FIG. 2 is a sectional view showing a second embodiment of the invention, and FIG. 3 is a partially broken view showing a third embodiment of the invention. FIG. 4 is a sectional view showing a modification of the embodiment shown in FIG. 3. 11.21.31.41...Scale base, 12゜2
2.32.42...Casing, 13,23°44.
...Fluid passage.

Claims (1)

[Claims] 1. A scale device including a scale base into which scale information is input and a casing to which the scale base is attached and held, the scale device having a fluid for controlling the temperature of the scale base. A scale device characterized by being provided with a fluid passage for circulation. 2. The scale device according to claim 1, wherein the scale base is made of a rod-shaped member, and the fluid passage is provided within the scale base. 3. The scale device according to claim 1, wherein the scale base is made of a thin plate-like member and is stretched over the surface of the casing, and the fluid passage is provided within the casing. 4. The scale device according to claim 1, wherein the scale base is made of a thin plate-like member and is disposed within a casing, and the fluid passage is provided within the casing.