JPH09155692A - Spindle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To be hardly influenced by noise and to simplify the structure of a device, in a spindle device to effect high speed measurement of temperatures at a plurality of points of a high speed rotation body. SOLUTION: A photo telemeter 7 for transmitting measuring data at the tip of a rotary shaft is mounted on the tip of a rotary shaft, and a photorelemeter 8 for receiving measuring data is fixed in a position situated facing the phototelemeter for transmitting measuring data in such a state to be separated therefrom. Thermocouples 6a are arranged in a plurality of points in the axial direction of a rotary shaft 2 and a wiring 6 is connected to the phototelemeter 7. A plurality of measuring data by a plurality of the thermocouples 6a are digitally serially transmitted at a high speed toward a photodiode for receiving the phototelemeter 8 from a light emission diode for transmitting the phototelemeter 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device used for a machine tool such as a machining center or an NC lathe, which is capable of accurately measuring temperature at a plurality of points inside a rotating body during high speed rotation. It is about.

[0002]

2. Description of the Related Art As a conventional method for measuring temperature, vibration and preload of a spindle for machine tools, a sensor is generally attached to a non-rotating portion such as a bearing outer ring or a housing, but a slip ring or FM is used. There is also a method of directly measuring the temperature of the rotating shaft by using a telemeter system. In addition, Japanese Patent Publication No. 4-8840 discloses that
An optical telemeter for transmitting and receiving an analog-transmitted optical signal is disclosed, and an amplitude modulation component (noise) generated when a transmitter is attached to a rotating body that rotates at high speed.
There has been proposed a method of reducing the occurrence of heat generation and accurately measuring the temperature and the like of a high-speed rotating body. In this method, a plurality of identical modulation signals for one measurement data are transmitted in parallel, which are received in parallel and added to reduce the occurrence of amplitude modulation components (noise).

[0003]

However, in the above-mentioned prior art, in the method utilizing the slip ring,
There are problems that noise is likely to be generated due to the contact resistance between the ring and the brush, and that high-speed rotation causes heat generation at the contact portion, making measurement impossible at high rotation speeds. In addition, the method using the FM telemeter system has a problem that the device becomes large and the cost is high, and it is easily affected by other radio waves.

Further, the above method using an optical telemeter has a problem that a large number of light emitting elements and light receiving elements are required for one measurement data, the structure of the apparatus becomes complicated and the cost becomes high. Furthermore, the large number of measurement points increases these problems. The present invention
It is an object of the present invention to solve such a problem of the conventional technique, and in a spindle device that measures a temperature and the like at a plurality of points of a high-speed rotating body by using a telemeter system, it is difficult to be affected by noise. Moreover, a device having a simple structure and low cost is provided.

[0005]

In order to solve the above-mentioned problems, a spindle device according to the present invention is provided with a plurality of sensors arranged on a rotating body, and is connected to the sensors and integrated with the rotating body. A telemeter transmitter provided so as to rotate, and a telemeter receiver fixedly installed in the vicinity of the rotating body to receive a signal from the telemeter transmitter, and detected by the plurality of sensors. In a spindle device for processing a plurality of data of a rotating body on the side of the telemeter receiver, the telemeter transmitter is an optical telemeter transmitter for digitally serially transmitting a plurality of data from the plurality of sensors as optical signals. The telemeter receiver is an optical telemeter receiver that receives an optical signal that has been digitally serially transmitted.

According to the spindle device of the present invention, since the optical telemeter transmitter and the receiver for digitally transmitting the optical signal are used, the spindle device is more resistant to noise as compared with the case of the analog transmission and is reliable at any rotation speed. It is sent and received. Moreover, the clock frequency of the optical telemeter system is 250 kHz or more, and the transmission rate is 500 kBPS.
Since it is higher than the above, high-speed signal transmission can be performed.

Further, since a plurality of data are serially transmitted, a plurality of data can be transmitted / received by the pair of light emitting element and light receiving element. As a result, the device can be made compact.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. 1 is a longitudinal sectional view showing an embodiment of a spindle device of the present invention, and FIG. 2 is a schematic diagram for explaining an optical telemeter system of the spindle device of FIG.

This spindle device is of a motor built-in type, and is composed of a rotor 31 rotating integrally with the rotary shaft 2 and a stator 32 fixed to the housing 4 on the outer periphery of the rotary shaft (rotating body) 2. It has a built-in brushless motor. Further, a plurality of rolling bearings 5 are mounted between the end members 41 and 42 forming both axial ends of the housing 4 and the tip end side and the base end side of the rotary shaft 2.

Through holes 51 are formed in the rotary shaft 2 at positions where the inner races of the rolling bearings 5 are in contact with each other and positions where the rotor 31 is mounted, the through holes 51 extending orthogonally to the axis. A thermocouple 6a is arranged on the outer peripheral surface of the rotary shaft 2 of each through hole 51,
The wiring 6 is wired in the hollow part of the rotary shaft 2 and
Is connected to an optical telemeter (optical telemeter transmitter) 7 attached to the tip of the. Also, this optical telemeter 7
An optical telemeter (optical telemeter receiver) 8 forming a pair with the optical telemeter 7 is fixedly installed at a position facing each other by about 20 mm (distance L in FIG. 2).

As shown in FIG. 2, the optical telemeter 7 on the rotating side digitally serially transmits a plurality of data from each thermocouple 6a to the optical telemeter 8 on the fixed side as an optical signal. A light emitting diode 71 for light transmission and a photodiode 72 for light reception are provided on the front end surface, and a multi-layer printed circuit board 73 in which a circuit for signal processing is formed and a driving battery 74 are provided.

The fixed-side optical telemeter 8 receives the optical signal from the rotating-side optical telemeter 7 and directs the thermocouples 6 toward the I / O interface 91 connected to the personal computer 9.
A signal indicating the measurement data of a is output, and a photodiode 81 for receiving an optical signal from the light emitting diode 71 on the rotation side and a light for channel designation toward the photodiode 72 on the rotation side are provided on the tip surface. A light emitting diode 82 for transmitting a signal is provided, and a circuit board 83 for signal processing is provided inside.

As shown in FIG. 1, at each axial position of the housing 4, a through hole 52 extending orthogonally to the axis and a hole 52 formed at a depth up to a midway portion of the end member 42.
a is formed, and a thermocouple 61a similar to the above is arranged in each through hole 52 and the hole 52a, and its wiring 61 is connected to the personal computer 9 from the outside of the housing 4 through another I / O interface. ing.

FIG. 3 is a block diagram showing a signal processing circuit on the rotation side. This circuit is composed of an amplifier 73a, an A / D converter 73b, a transmitting circuit 73c, a receiving circuit 73d, and a synchronous clock generating circuit 73e. There is. Also,
FIG. 4 is a block diagram showing a signal processing circuit on the fixed side,
This circuit includes a receiving circuit 83a, a transmitting circuit 83b, a synchronous clock generating circuit 83c, a transmitting clock generating circuit 83d,
It is composed of shift registers 83e and 83f and an I / O interface 91.

The fixed side synchronous clock generating circuit 83
c, transmission clock generation circuit 83d, shift register 83
The e, 83f and the I / O interface 91 are formed on one board 92, and this board 92 is connected to the expansion slot 9a of the personal computer 9. The shift register 83e is a serial input / parallel output type, and the shift register 83f is a parallel input / serial output type.

In the circuit on the rotation side, the amplifier 73a
Amplifies the voltage generated in each thermocouple 6a and outputs it as temperature measurement data to the A / D converter 73b. A / D
The converter 73b converts the analog signal from the amplifier 73a into a digital signal, and the synchronization clock generation circuit 73e synchronizes the control byte (this control byte is transmitted as an optical signal from the light emitting diode 82 on the fixed side. Is received by the photodiode 72 and is output to the synchronous clock generating circuit 73e and the A / D converter 73b via the receiving circuit 73d.),
The temperature measurement data of the channel designated by the read control byte is output to the transmission circuit 73c.

As a result, from the light emitting diode 71 connected to the transmission circuit 73c, the light obtained by converting the plurality of temperature measurement data by each thermocouple 6a into a digital serial signal is transmitted to the fixed side photodiode 81. It In the circuit on the fixed side, the receiving circuit 83a inputs the digital serial signal received by the photodiode 81 to the shift register 83e while synchronizing with the synchronous clock generating circuit 83c. As a result, a serial signal indicating a plurality of temperature measurement data is converted into a parallel signal and output to the personal computer 9 via the I / O interface 91.

The optical signal indicating the control byte transmitted to the rotating side is sent from the personal computer 9 to the I / O interface 91.
The 8-bit parallel data output via the shift register 83f is stored in the shift register 83f, and the transmission clock generation circuit 83d
By being input to the shift register 83f while being synchronized with each other, it is converted into serial data and then transmitted from the light emitting diode 82 via the transmission circuit 83b.

Further, each thermocouple 6 input to the personal computer 9
The temperature measurement data of a is output to a screen, for example, and is output to the rotary shaft 2
It is used to check the change over time in the temperature distribution in the axial direction of, and to check the difference in the degree of temperature rise at each point as the rotation speed increases. Alternatively, when a predetermined control circuit or the like is connected, the temperature measured by the thermocouple 6a becomes a predetermined value or more, or the difference from the temperature measured by the thermocouple 61a (on the housing side) becomes a predetermined value or more. In such a case, the rotation shaft 1 may be stopped from rotating.

FIG. 5 is a longitudinal sectional view showing another embodiment. This spindle device has a plurality of rolling bearings 5 arranged on the base end side of the rotary shaft 2 in addition to the structure of FIG. A strain gauge 60a is arranged on the inner ring spacer 50,
A strain gauge 60 a and a through hole 51 a for the wiring 60 are formed in the rotary shaft 2, and the wiring 60 is connected to the optical telemeter 7. Then, based on the measurement data from the strain gauge 60a, the preload control is performed by a program of the personal computer 9, for example.

As described above, according to the spindle device of each of the above embodiments, since the optical signal is digitally transmitted from the optical telemeter 7 on the rotating side to the optical telemeter 8 on the fixed side, the optical axis is strong against noise and the rotating shaft 2 Since the optical signals are reliably transmitted and received at any rotation speed, the measurement of the temperature distribution in the axial direction of the rotary shaft 2 and the control based on the measured value are accurately performed. In addition, since the optical telemeter system is used, the clock frequency is 250
Since it is as high as kHz or more and the transmission rate is 500 kBPS or more, high-speed signal transmission is possible. In addition, a plurality of data is transmitted and received by the pair of light emitting diodes 71 by serial transmission.
And because it can be performed by the photodiode 81,
The telemeter system can be made small and inexpensive.

[0022]

As described above, according to the spindle device of the present invention, it is possible to accurately measure the temperature and the like at a plurality of points even at a high speed rotating body at high speed. . Moreover, even if there are many measurement points, the structure of the device can be simplified, so that the cost can be kept low.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a spindle device of the present invention.

FIG. 2 is a schematic diagram for explaining an optical telemeter system of the spindle device of FIG.

FIG. 3 is a block diagram showing a rotation-side signal processing circuit in the optical telemeter system used in the embodiment.

FIG. 4 is a block diagram showing a fixed-side signal processing circuit in the optical telemeter system used in the embodiment.

FIG. 5 is a vertical sectional view showing another embodiment of the spindle device of the present invention.

[Explanation of symbols]

 2 rotating shaft (rotating body) 6a, 61a thermocouple (sensor) 60a strain gauge (sensor) 7 optical telemeter (optical telemeter transmitter) 8 optical telemeter (optical telemeter receiver)

Claims (1)

[Claims] 1. A plurality of sensors arranged on a rotating body, a telemeter transmitter connected to the sensors and provided so as to rotate integrally with the rotating body, and a telemeter transmitter from the telemeter transmitter. A telemeter receiver fixedly installed in the vicinity of the rotating body for receiving a signal, and a spindle for processing a plurality of data of the rotating body detected by the plurality of sensors on the side of the telemeter receiver. In the apparatus, the telemeter transmitter is an optical telemeter transmitter that digitally serially transmits a plurality of data from the plurality of sensors by an optical signal, and the telemeter receiver receives the digital serially transmitted optical signal. A spindle device, which is an optical telemeter receiver that operates.