JP2006062081A - Die processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die processing device including a spindle to work in high speed rotation, having a high rotational accuracy and a high static stiffness/dynamic stiffness, and capable of performing processing with a high efficiency and high accuracy. <P>SOLUTION: The spindle 4 of a spindle device 1 to rotate a tool 11 is supported by static pressure-magnetic complex bearings 6-9 and furnished with current sensing means 15-18 to sense the excitation current of the complex bearings 6-9 and a processing condition grasping means 19 to grasp the processing condition from the sensed amperages. Further an external command respond on-off means 20 is installed, and the complex bearings 6-9 are made possible to support only with their static pressure gas bearing part in conformity to the external command. Further a means 76 is installed to measure the temperature of a housing 5, while an output means 77 is installed to work for temperature measurement. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a die processing apparatus used for cutting or grinding of a molding die, and more particularly to a die processing apparatus having a spindle device provided with a hydrostatic magnetic compound bearing.

Recently, high-efficiency and high-precision machining has attracted attention in mold machining. In order to realize such machining, a spindle device capable of high-speed rotation, high rotation accuracy, high static rigidity and dynamic rigidity is required, and the optimum machining conditions are detected while detecting the machining state. It is required to process with.
However, such a requirement could not be satisfied due to the limitation of the function of the bearings equipped in the spindle device.
On the other hand, the present applicant has proposed a spindle device used for general high-speed cutting that uses a hybrid non-contact bearing in which a static pressure gas bearing and a magnetic bearing are combined (Japanese Patent Application No. 10-097505). Such). According to this, it is possible to obtain a bearing that takes advantage of the features of both bearings, that is, the excellent dynamic rigidity and rotational accuracy of the static pressure gas bearing and the excellent static rigidity of the magnetic bearing.

The present invention is intended to meet the various requirements as described above by supporting a main shaft with a hydrostatic magnetic compound bearing in which a hydrostatic gas bearing and a magnetic bearing are combined in a die processing machine. is there. In general, the machining load for detecting the machining state is estimated by estimating the machining load from the measured value of the motor output for rotating the spindle.
However, a mold processing apparatus that uses such a hydrostatic magnetic composite bearing and controls processing conditions also has the following unsolved problems.
1) The method of estimating the machining load from the motor output measurement value requires a dedicated measuring device for detecting the machining state, and the system cost is high.
2) In the method of detecting the machining state from the motor output measurement value, the machining state related to the rotation frequency of the spindle cannot be detected.
3) The hydrostatic magnetic compound bearing has the characteristics of both a hydrostatic gas bearing and a magnetic bearing. For this reason, when the resolution of the magnetic bearing sensor is low, the rotational accuracy of the spindle is determined by this resolution, and the high rotational accuracy of the static pressure gas bearing cannot be fully utilized.
4) When the hydrostatic magnetic compound bearing spindle device is rotated at a high speed, the temperature of the main shaft and the housing increases due to the loss (windage loss) in the hydrostatic gas bearing. The axial position of the tool at the tip of the spindle device changes. For this reason, highly accurate processing becomes difficult.

An object of the present invention is to provide a die machining apparatus capable of high-speed rotation of a spindle, high rotational accuracy, high static rigidity and dynamic rigidity, and capable of high-efficiency and high-precision machining.
Another object of the present invention is to reduce the cost by making it unnecessary to provide an expensive load measuring device while making it possible to detect a machining state during machining.
Still another object of the present invention is to enable detection of a static load on the spindle. Still another object of the present invention is to enable detection of a machining state related to the rotational frequency of the spindle with a simple configuration.
Still another object of the present invention is to make it possible to set the optimum bearing according to the desired machining conditions at any time, to effectively exert the function of the hydrostatic magnetic composite bearing, and to obtain higher rotational accuracy. It is to be.
Still another object of the present invention is to make it possible to quickly set an optimum bearing in accordance with machining conditions that change with the progress of machining.
Still another object of the present invention is to realize high efficiency and high precision machining by achieving high efficiency during rough machining and high precision during finishing machining.
Still another object of the present invention is to enable high-precision processing even when the temperature of the housing or the like changes due to windage loss or the like in a static pressure gas bearing.
Still another object of the present invention is to make it possible to easily recognize an abnormality when the abnormality such as a rise in the housing temperature occurs and to deal with it immediately.
Still another object of the present invention is to enable monitoring and control of a machining state at a remote place.

The structure of this invention is demonstrated with FIG. 1 corresponding to embodiment. The mold processing apparatus according to the present invention is a mold processing apparatus having a spindle device (1) for rotating a tool (11), wherein the spindle device (1) includes a static pressure gas bearing (6A to 9A) and a magnetic bearing. The basic structure is such that the main shaft (1) is supported by hydrostatic magnetic composite bearings (6-9) combined with (6B-9B). According to this, a bearing structure that takes advantage of the features of both bearings, that is, excellent dynamic rigidity and rotational accuracy of static pressure gas bearings (6A to 9A) and excellent static rigidity of magnetic bearings (6B to 9B), is obtained. 1) High-speed rotation is possible, with high rotational accuracy, high static rigidity and dynamic rigidity, enabling highly efficient and highly accurate machining.
The following first to fourth inventions, which are developments of the present invention, are based on the above-described configuration and are provided with any of the following matters.
According to a first aspect of the present invention, there is provided a die machining apparatus comprising: current detection means (15-18) for detecting an excitation current of the magnetic bearing (6B-9B); and current detection of the current detection means (15-18). Machining state grasping means (19) for grasping the machining state by the tool (11) from the value.
According to this configuration, the machining state grasping means (19) can grasp the machining state from the detected current value of the excitation current of the magnetic bearings (6B to 9B) in the hydrostatic magnetic composite bearings (6 to 9). That is, when the spindle (4) tries to displace in the radial direction or the like with a load acting on the tool (11) during machining, the exciting current of the magnetic bearings (6B to 9B) is restored to restore the displacement. It changes with the control function which (6B-9B) has. For this reason, it is possible to grasp the machining state such as tool wear, tool damage, and machining failure from the excitation current. Since the machining state grasping means (19) is provided in this way, the high function of the hydrostatic magnetic composite bearings (6 to 9), that is, high speed rotation, high rotation accuracy, high static rigidity and dynamic rigidity, In combination, it is possible to perform machining under optimum machining conditions while detecting the machining state, and it is possible to perform machining with higher efficiency and higher accuracy utilizing the features of the hydrostatic magnetic composite bearings (6 to 9). In addition, the detectors only need to be provided with current detection means (15-18) for the excitation current of the magnetic bearings (6B-9B), and it is not necessary to provide an external load measuring device, and the motor current Compared to the one that detects, it is simple and can be made at low cost.

In the first invention, the machining state grasping means (19) smoothes the current detection value of the current detection means (15-18), and the static load on the spindle from the smoothed value output of the current smoothing section. It is good also as what has a processing state grasping part which carries out conversion and grasps a processing state from the static load conversion result.
As described above, by grasping the machining state from the static load conversion result, it is possible to easily and accurately grasp the machining state necessary for the control without being influenced by the load fluctuation or disturbance generated in a minute time.

According to a second aspect of the present invention, there is provided a die machining apparatus including a displacement detection means (28, 38) for detecting a displacement of the main shaft (4), and a tool (11) based on a displacement detection value of the displacement detection means (28, 38). ) And a machining state grasping means (19) for grasping the machining state.
When the main shaft (4) is displaced by a load acting on the tool (11) during machining, the displacement is detected by the displacement detecting means (28, 38). Therefore, the machining state can be grasped from this displacement detection value. Therefore, by providing the above-described machining state grasping means (19), the hydrostatic magnetic composite bearings (6 to 9) are capable of high-speed rotation, coupled with the functions of high rotational accuracy, high static rigidity and dynamic rigidity. It is possible to perform machining under optimum machining conditions while detecting the machining state, and it is possible to perform machining with higher efficiency and higher accuracy utilizing the features of the hydrostatic magnetic composite bearings (6 to 9). Moreover, since the displacement detection means (28, 38) are detection means generally provided in the magnetic bearings (6B-9B) for controlling the magnetic bearings (6B-9B), the displacement detection means (28, 38) can be processed without providing dedicated detection means. The state can be grasped, and the machining accuracy can be improved at low cost.

In the first and second inventions, the machining state grasping means (19) includes a frequency analyzing section for analyzing the frequency of the output of the current detecting means (15-18) or the displacement detecting means (28, 38), and the frequency analysis. A machining state grasping unit that grasps the machining state from the amplitude of each frequency component at the time of machining output from the unit may be included.
The load acting on the tool appears as vibration of the tool from the natural vibration of the tool, workpiece, processing device, or spindle speed, etc. The processing state such as tool damage is the vibration frequency depending on the type of tool damage, processing failure, etc. Shows a peculiar tendency. Therefore, by providing a frequency analysis unit and a machining state grasping unit that grasps the machining state from the amplitude of each frequency component at the time of machining, a highly accurate machining state that cannot be observed by detecting the average load of each frequency component Can be detected. In addition, since frequency analysis is performed, it is possible to analyze a large number of frequency bands with a simple configuration compared to a frequency filter.

According to a third aspect of the present invention, there is provided a die machining apparatus comprising a spindle controller (3) for controlling the hydrostatic magnetic composite bearings (6-9), and a magnetic bearing (in accordance with a command external to the spindle controller (3)). 6B to 9B) is provided with an external command response on / off means (20) for turning on / off the excitation.
When the magnetic bearings (6B to 9B) are turned off, the main shaft (4) is supported only by the static pressure gas bearings (6A to 9A) in the static pressure magnetic composite bearings (6 to 9), and the magnetic bearings (6B to 9B). Is turned on, the main shaft (4) is supported by both the static pressure gas bearings (6A to 9A) and the magnetic bearings (6B to 9B). Support by both bearings (6A to 9A, 6B to 9B) and support by only the static pressure gas bearings (6A to 9A) are switched by a command from the outside of the spindle controller (3). Therefore, the optimal bearing setting according to desired processing conditions can be performed at any time, the functions of the hydrostatic magnetic composite bearings (6 to 9) can be effectively exhibited, and higher rotation accuracy can be obtained.

  The external command for excitation on / off may be a command given from a numerical control device (14) that controls the die machining apparatus machine section (13a). By giving the excitation on / off command from the numerical controller (14) in this way, the optimum bearing setting can be quickly made according to the machining conditions that change as the machining progresses.

The external command for excitation on / off may be a command to turn on the magnetic bearing during roughing and to turn off the magnetic bearing during finishing.
As a result, high efficiency can be achieved during rough machining, and high precision can be achieved during finishing machining, thereby realizing high-efficiency and high-precision machining. That is, generally, high-efficiency and high-precision machining is performed in two stages, rough machining and finishing. In rough machining, the removal amount of work material per unit time is increased to aim at high efficiency, and in finishing processing, the removal amount is reduced to aim at high accuracy. For this reason, the load on the spindle becomes large during rough machining, and the rigidity and load capacity are required as the spindle performance, and high rotational accuracy is required for finishing machining. By turning on / off the excitation as described above, it is possible to meet the demands according to such processing types.

According to a fourth aspect of the present invention, there is provided a mold processing apparatus comprising: a temperature measuring means (76) of the spindle housing (5); and a temperature measurement corresponding output means for obtaining a predetermined output from the temperature measurement value of the temperature measuring means (76). (77) and temperature corresponding processing means (100) for performing a predetermined process from the output of the means (77).
The predetermined output of the temperature measurement corresponding output means (77) is:
The following 1) to 3), that is,
1). The output of the temperature measuring means (76) (that is, the temperature measurement value),
2). A converted value obtained by converting the temperature measurement value of the temperature measurement means (76) into the axial position of the spindle tip or the tip of the tool (11) by a predetermined thermal displacement calculation;
3). An abnormal signal obtained by comparing the measured temperature value or the converted value with a set value,
At least one of them.
The converted value may be a value that can be handled as position data, and may be a value proportional to actual position data or a value indicating a displacement amount from a reference position.
In the case of this configuration, even if the temperature of the spindle device (1) rises due to heat generation due to loss (windage loss) or the like of the static pressure gas bearing, the temperature measurement value output from the temperature measurement corresponding output means (77) or heat The feed amount can be corrected based on the converted value of the axial position that has been subjected to the displacement calculation, and the workpiece can be machined with high accuracy. When the output of the temperature measurement corresponding output means (77) is an abnormal signal, when the spindle is abnormal such as an excessive rise in housing temperature, the abnormal signal is detected externally and the spindle device (1) is stopped as appropriate. Can be processed quickly.

In the present invention, a cooling means (71) for cooling the housing (5) in which the main shaft (4) is installed is provided, and in response to the output of the temperature measurement corresponding output means (77), the cooling means (71) ( A cooling control means (82) for controlling the cooling operation of FIG. 16 corresponding to the embodiment may be provided.
Thus, by appropriately controlling the cooling means (71) with the output corresponding to the temperature measurement result, appropriate cooling of the housing (5) can be easily performed.

In this invention, a spindle positioning mechanism (75) for moving the housing (5) in which the main shaft (4) is installed in the axial direction of the main shaft (4) is provided, and output from the temperature measurement corresponding output means (77). You may provide the temperature correction means (83) which controls the said spindle positioning mechanism according to a temperature measurement value or the said conversion value.
When the spindle positioning mechanism (75) is provided in this way, the workpiece can be processed with high accuracy by controlling the temperature of the spindle with the temperature measurement value or its converted value.

  In the present invention, the rotational drive source (10) for rotating the main shaft (4) may be a motor built in the housing (5) where the main shaft (1) is installed.

In this invention, you may provide the communication means (86) which transmits the grasping | ascertainment content of the processing state grasping means (19) to a remote place via a communication line (87).
By providing the communication function by the communication line (87) in this way, it is possible to grasp the load and machining state of the tool at a remote place, and to centrally manage the spindle devices of a large number of die machining apparatuses at a remote place. Is possible.
Moreover, in this invention, you may provide the communication means (86) which transmits the output of a temperature measurement corresponding | compatible output means (77) to a remote place via a communication line (87).
Thereby, the temperature of the housing (5) and the thermal displacement state accompanying the temperature change can be grasped at a remote place, and centralized management at the remote place becomes possible.

Since the die machining apparatus of the present invention uses a hydrostatic magnetic composite bearing to support the main shaft, the main shaft can be rotated at a high speed, has high rotational accuracy, high static rigidity and dynamic rigidity, and has high efficiency. Can be used for high-precision machining.
When a hydrostatic magnetic composite bearing is used and each of the above-described means is provided, processing with higher efficiency and higher accuracy can be performed.
When a current detection means for detecting the excitation current of the magnetic bearing of the hydrostatic magnetic composite bearing and a machining state grasping means for grasping the machining state by the tool from the current detection value of this current detection means, load measurement is provided externally. It is possible to grasp the machining state without providing a device, and to perform machining with higher accuracy under optimum machining conditions.
When a current smoothing unit that smoothes the current detection value of the current detection means is provided, it is possible to detect the static load on the spindle.
When the displacement detection means for detecting the displacement of the main spindle and the machining state grasping means for grasping the machining state by the tool from the displacement detection value of the displacement detection means, the machining state is provided without providing dedicated sensors. Can be grasped, and the cost can be further reduced.
When a frequency analysis unit for analyzing the frequency of the output of the current detection means or the displacement detection means is provided, it is possible to detect the machining state related to the rotation frequency of the spindle with a simple configuration.
When an external command response on / off means that turns on and off the magnetic bearing excitation by a command external to the spindle controller is provided, the optimum bearing setting according to the desired machining conditions can be made at any time, and the function of the hydrostatic magnetic composite bearing is effective. To achieve even higher rotational accuracy.
In particular, when an excitation on / off command is given from the numerical control device, it becomes possible to quickly set the optimum bearing according to the machining conditions that change as the machining progresses. In particular, when the magnetic bearing is turned on during rough machining and the magnetic bearing is turned off during finishing, high efficiency can be achieved during rough machining, and high precision can be achieved during finishing machining. Can be realized.
If the temperature measurement means for the spindle housing and the temperature measurement output means for obtaining a predetermined output from the measured value each time are provided, the mold can be processed with high accuracy even if the temperature of the housing or the like changes. it can.
When an abnormal signal is obtained by comparing the measured temperature value or its dimension-converted value with a set value, it can be dealt with urgently when the housing temperature rises abnormally.

An embodiment of the present invention will be described with reference to the drawings. FIG. 18 is a conceptual diagram showing the whole mold processing apparatus. This mold processing apparatus includes a spindle apparatus 1 that rotates a tool 11 and a table apparatus 51 that moves a workpiece W to be processed into a mold. The spindle device 1 includes a spindle device main body 2 composed of a mechanism portion and a spindle controller 3 that controls the spindle device main body 2. The spindle device main body 2 and the table device 51 constitute a processing device main body 13 a, and the processing device main body 13 a is controlled by the numerical control device 14.
The spindle device main body 2 is installed on the base 52 through a guide 53 and a spindle installation table 74 so as to be able to advance and retract at a position opposite to the table device 51, and is driven to advance and retract in the spindle axis direction (Z-axis direction) by the spindle positioning mechanism 75. Is done. As shown in FIG. 19, the table device 51 is provided with a table 55 on which a workpiece W is placed so as to be movable in two orthogonal axis directions (X and Y directions) perpendicular to the spindle axis direction (Z axis). It moves forward and backward by driving the table driving devices 56 and 57 in each direction. The table 55 has a two-stage structure in which an upper table 55b is installed so as to be movable in the X-axis direction on a lower table 55a that is movable in the Y-axis direction. The table driving devices 56 and 57 for each axis and the spindle positioning mechanism 75 are each composed of a ball screw and a servo motor. In this example, the spindle axis direction (Z axis) is vertical, and the movement direction (X, Y direction) of the table device 51 is horizontal. Note that the spindle axis direction (Z axis) may be a horizontal direction or an inclination direction, and the table moving direction (X, Y direction) may be a corresponding direction in the vertical plane.

First, the outline of the main body 2 and the controller 3 of the spindle device 1 will be described. FIG. 1 is a block diagram showing a conceptual configuration of the spindle device 1.
The spindle device main body 2 supports the spindle 4 by a plurality of radial hydrostatic magnetic compound bearings 6 and 7 and axial hydrostatic magnetic compound bearings 8 and 9 installed in a housing 5, and a spindle drive source 10 is provided. It is a thing. Each of the static pressure magnetic compound bearings 6 to 9 is a combination of the static pressure gas bearings 6A to 9A and the magnetic bearings 6B to 9B, and is controlled by the spindle controller 3. The main shaft 4 has a chuck 12 that holds the tool 11 at the tip.
The spindle controller 3 uses the current detection means 15-18 for detecting the excitation current of the magnetic bearings 6B-9B constituting the hydrostatic magnetic composite bearings 6-9, and the tool 11 based on the current detection values of the current detection means 15-18. Processing state grasping means 19 for grasping the processing state is provided. Further, the spindle controller 3 is provided with an external command response on / off means 20 for turning on and off the excitation of the magnetic bearings 6B to 9B according to an external command sent from the numerical controller 14 or the like. Further, the spindle controller 3 is provided with temperature measurement corresponding output means 77 for obtaining a predetermined output from the output of the temperature measurement means 76 provided in the housing 5.

The spindle device main body 2 will be described with reference to FIGS. The spindle device 1 is a built-in motor type spindle device of the processing device 13, and the spindle drive source 10 is installed in a housing 5 in which the bearings 6 to 9 are installed. The spindle drive source 10 composed of this motor includes a rotor 21 provided integrally with the main shaft 4 and a stator 22 installed on the housing 5. The housing 5 is formed in a substantially cylindrical shape. The spindle drive source 10 may not be a built-in type, but may be provided outside the housing 5 to transmit rotation to the main shaft 4 via a transmission mechanism.
In this example, the bearings 6 to 9 and the spindle drive source 10 are arranged such that the front part (tool side part) and the rear part of the main shaft 4 are supported by radial hydrostatic magnetic composite bearings 6 and 7, and the middle part is axial. It is configured such that a spindle drive source 10 is arranged at the rear end, supported by static hydrostatic magnetic composite bearings 8 and 9. Instead of the above arrangement, the spindle drive source 10 may be arranged between the radial type bearings 6 and 7 and the axial type bearings 8 and 9 may be arranged at arbitrary positions on the main shaft 4. Further, the axial bearings 8 and 9 may be non-contact bearings, and a single magnetic bearing or a static pressure gas bearing may be used instead of the static pressure magnetic composite bearing.

  Each of the radial type hydrostatic magnetic composite bearings 6 and 7 has the same configuration. FIG. 3 shows a cross section of one of the bearings 6 and FIG. 4 shows an enlarged vertical cross section. The hydrostatic magnetic composite bearings 6 and 7 are obtained by combining hydrostatic gas bearings 6A and 7A and magnetic bearings 6B and 7B, respectively. The term “composite” as used in this specification means that both static pressure and magnetic bearings are combined so that a common part is generated. For example, a common part (radial bearing) is formed on a static pressure gas bearing surface and a magnetic bearing surface. Then, the axial overlapping portion) may be generated, or at least a part of components may be shared by both types of bearings.

  In this embodiment, as shown in FIG. 4, by providing the diaphragm 23a of the static pressure gas bearings 6A and 7A on the core 23 of the electromagnet of the magnetic bearings 6B and 7B, the bearing components can be shared and the bearing surface A part is overlapped in the axial direction. The core 23 is opposed to a pair of main core portions 23a, 23a separated in the axial direction, a connecting core portion 23b connecting the main core portions 23a, 23a, and spindle ends of both the main core portions 23a, 23a. A longitudinal section is formed in a C shape by the extending portions 23c, 23c. The inner diameter side surfaces of the main core portion 23a and the extending portion 23c are cylindrical surfaces that form a predetermined magnetic gap with the main shaft 4. The magnetic bearings 6 </ b> B and 7 </ b> B are obtained by winding a coil 25 around the connecting core portion 23 b of the core 23. The coil 25 is embedded in a nonmagnetic material 26 such as a resin material.

The static pressure gas bearings 6A and 7A are formed on the inner surface of the core 23 and the nonmagnetic body 26 to form a bearing gap d between the main shaft 4 and the main cores of the core 23. The diaphragm 24a is provided in the portions 23a and 23a and opens to the hydrostatic bearing surfaces 6Aa and 7Aa. The restrictor 24a is provided at the tip of the air supply hole 24 opened on the outer diameter side surface of each main core portion 23a.
As shown in the stepped cross section in FIG. 3, the cores 23 are arranged at a plurality of circumferential locations around the main shaft 4 (four locations in the example in the figure) and are fixed to the housing 5. A gap between adjacent cores 23 in the circumferential direction is filled with a nonmagnetic material 27 such as a resin material. The nonmagnetic material 27 may be integrated with the nonmagnetic material 26 (FIG. 4) around the coil 25.

  The magnetic bearings 6 </ b> B and 7 </ b> B have displacement detection means 28 that detects the displacement of the magnetic gap between the main shaft 4 and the core 23. The displacement detection means 28 may directly detect the amount of displacement, but in this example, by detecting the static pressure of the hydrostatic bearing gap d, the detected pressure value is converted into the amount of displacement. Thus, the displacement of the magnetic gap is detected. Specifically, the displacement detection means 28 includes a pressure detection air passage 28a having a tip opened in the hydrostatic bearing gap d, and a sensor 28b communicating with the air passage 28a. The sensor 28b is disposed at a position away from the core 23 in the axial direction as shown in FIG. The air passage 28a is formed of a fine hole or a pipe, and the hydrostatic bearing gap d is opened at a portion of the nonmagnetic material 26 between the extending portions 23c and 23c of the core 23. FIG. 2 shows the opening positions of the throttle 24a and the air passage 28a shifted in the circumferential direction in order to make the drawing easy to see, but they are actually the same position in the circumferential direction.

FIG. 5 is an enlarged view of the axial type hydrostatic magnetic composite bearings 8 and 9. The pair of bearings 8 and 9 are installed in the housing 5 so as to face both surfaces of the flange portion 4 a provided on the main shaft 4, and constitute one double-sided axial type static pressure gas bearing 30. . The hydrostatic magnetic composite bearings 8 and 9 on both sides have the same configuration. These hydrostatic magnetic composite bearings 8 and 9 are obtained by combining hydrostatic gas bearings 8A and 9A and magnetic bearings 8B and 9B, respectively.
In this embodiment, by providing the diaphragm 33a of the static pressure gas bearings 8A and 9A on the core 33 of the electromagnet of the magnetic bearings 8B and 9B, the bearing components are shared and a part of the bearing surface overlaps in the axial direction. It is like that. The core 33 is formed in a C-shaped longitudinal section so that an opening 33d is formed on the surface facing the spindle flange 4a, and a coil 35 is accommodated therein. The opening 33d is filled with a nonmagnetic material. In the illustrated example, the core 33 has an assembly configuration of an inner peripheral core portion 33a and an outer peripheral core portion 33b having an L-shaped cross section, but may be a single piece. A spacer 29 is adjacent to the core 33 in the axial direction.

  The axial type static pressure gas bearings 8A and 9A are provided on the core 33 and static pressure bearing surfaces 8Aa and 9Aa which are formed on the side surface of the core 33 and form a bearing gap d2 with the spindle flange 4a. The diaphragm 34a is open to the pressure bearing surfaces 8Aa and 9Aa. The restrictor 34 a is provided at the tip of the air supply hole 34 that opens to the outer diameter side surface of the core 33.

  The axial type magnetic bearings 8B and 9B have a displacement detecting means 38 for detecting the displacement of the magnetic gap between the spindle flange 4a and the core 33. This displacement detection means 38 may also directly detect the amount of displacement, but in this example, by detecting the static pressure in the hydrostatic bearing gap d2, the detected pressure value is converted into the amount of displacement. Thus, the displacement of the magnetic gap is detected. Specifically, the displacement detection means 38 includes a pressure detection air passage 38a having a tip opened in the hydrostatic bearing gap d2, and a sensor 38b (FIG. 2) communicating with the air passage 38a.

  In the static pressure gas bearings 6A to 9A of the static pressure magnetic composite bearings 6 to 9, compressed air or other compressed gas is supplied to the air supply holes 24 and 24 from an air supply inlet 40a of the air supply hole 40 provided in the housing 5. Is supplied.

  The control system will be described. As shown in FIG. 1, the spindle controller 3 has a power source 41, an electromagnet power circuit 42, and a control means 43 in the controller basic part 3a. The electromagnet power circuit 42 is a means for supplying the current supplied from the power supply 41 as an excitation current to the magnetic bearings 6B to 9B of the hydrostatic magnetic composite bearings 6 to 9 according to the control of the control means 43. Etc. The control means 43 controls the excitation currents of the magnetic bearings 6B to 9B so that the displacement of the main shaft 4 is restored according to the detection values of the displacement detection means 28 and 38 in the hydrostatic magnetic composite bearings 6 to 9. Means. Specifically, the control means 43 gives an excitation current control command in accordance with, for example, a result obtained by calculating the detection values of the displacement detection means 28 and 38 by an integration circuit or a proportional integration circuit.

In this embodiment, the spindle controller 3 of this basic configuration is provided with the current detection means 15 to 18, the machining state grasping means 19, the external command response on / off means 20, and the temperature measurement corresponding output means 77, and the external output means. 44, and the numerical controller 14 is provided with an excitation on / off command generation means 45, a processing state correspondence processing means 46, and a temperature correspondence processing means 100. For example, a current detector is used as the current detection means 15-18.
As shown in FIG. 6, the numerical control device 14 includes a numerical control function unit 14 a and a programmable controller function unit 14 b, and the numerical control function unit 14 a decodes the machining program 50 and each axis of the machining apparatus body 13 a. And the sequence command described in the machining program 50 is transferred to the programmable controller function unit 14b. The programmable controller function unit 14b is means for performing sequence control of the machining apparatus main body 13a according to a predetermined sequence program. The programmable controller function unit 14b is provided with the excitation on / off command generation unit 45 and the machining state corresponding processing unit 46. ing. In the figure, the temperature correspondence processing means 100 is not shown.

FIG. 8 shows a basic conceptual configuration of the machining state grasping means 19. The machining state grasping means 19 is a means for grasping the machining state by the tool 11 from the current detection values of the current detection means 15 to 18 as described above, and the grasping result is sent to the machining state correspondence processing means 46 of the numerical controller 14. Sent. This grasping result may be the current detection value as it is, may be a comparison result obtained by comparing the current detection value with the set value, and may be a value obtained by performing a predetermined calculation process from the current detection value. Further, it may be a result of comparing the arithmetic processing with a set value. When the control means 43 controls the excitation current according to the value calculated by the integration circuit or the proportional integration circuit as described above, the machining state grasping means 19 The static load of the spindle 4 is converted from the detected value itself.
Further, the machining state grasping means 19 outputs the grasping result of the machining state individually with respect to the detected current values of the respective current detecting means 15 to 18, but the detected current values of the plurality of current detecting means 15-18. Even if the result of grasping the machining state comprehensively determined is output, the machining state is grasped only by one or a plurality of detected current values of each of the current detection means 15 to 18. May be.

FIG. 9 shows one specific example of the machining state grasping means 19. In this example, the machining state grasping means 19 includes a current smoothing section 19a that smoothes each of the current detection values of the current detection means 15 to 18, and a spindle static load from the smoothed value output of the current smoothing section 19a. And a machining state grasping part 19b for grasping the machining state from the static load conversion result. Specifically, the machining state grasping unit 19b compares, for example, the converted spindle static load with a set value, and outputs an abnormality when the set value is exceeded.
FIG. 12 shows an example of processing performed by the machining state grasping unit 19b. The static load of the main shaft 4a becomes a constant value as shown by the curve a when constant machining is continued. When the tool wear progresses or the tool is damaged, the curve changes as shown by the curve b or the curve c. Therefore, an upper limit value and a lower limit value that are allowable as an appropriate load are set as set values, and when the value is within the range (shaded portion), the tool is normal, and deviates from this range as curves b and c. In this case, an abnormal signal of tool abnormality is output as a grasping result of the machining state. In this specification, “converting the smooth value output to the spindle static load” means converting the smooth value output to a value that is easy to compare with the set value as the load, in the case where the load is converted into a unit of load. Includes both cases of conversion.

FIG. 10 shows another specific example of the processing state grasping means 19. In this example, the machining state grasping means 19 includes a frequency analysis section 19c that performs frequency analysis on each current detection value of the current detection means 15 to 18, and each frequency component at the time of machining output from the frequency analysis section 19c. And a machining state grasping part 19d for grasping the machining state from the amplitude.
FIG. 13 shows an example of processing performed by the machining state grasping unit 19c. When the constant processing is continued, the frequency analysis result of the current detection value becomes a substantially constant waveform in which the amplitude of each frequency component is different as shown by the curve d. Therefore, setting values m1, m2,... That can be tolerated for each predetermined frequency band are set, and the amplitude value of any frequency component is, for example, a corresponding frequency band as shown by a curved line portion e indicated by a broken line. When the set value m2 is exceeded, it is determined that the tool is abnormal.

Note that the machining state grasping means 19 grasps the machining state from the current detection values of the current detection means 15 to 18 in each of the specific examples, but the machining state grasping means 19 includes the displacement detection means 28 and 38. It is good also as what grasps a processing state from a detected value.
For example, as shown in FIG. 11, the machining state grasping means 19 includes a frequency analysis unit 19e that performs frequency analysis on the outputs of the displacement sensor amplifiers of the displacement detection means 28 and 38, and a processing time output from the frequency analysis unit 19e. A machining state grasping unit 19f that grasps the machining state from the amplitude of each frequency component may be included.

  As shown in FIG. 1, the machining state grasping means 19 of each configuration has a setting unit 19g, and when the setting unit 19g outputs a grasping result of the machining state in comparison with a set value, Used. The setting unit 19g is set such that various setting values can be changed or a plurality of preset setting values can be selected in accordance with commands from the numerical controller 14 or other means. For example, when machining with different loads such as rough machining and finishing machining is performed during operation of the spindle device, it is necessary to determine whether the tool is good or bad with a set value corresponding to the load. The setting unit 19g can change such a set value, and detects a signal accompanying a change in processing of the numerical controller 14 to change the set value.

The external output means 44 is the current detection values of the current detection means 15 to 18, the progress and results obtained by the machining state grasping means, for example, the smoothing value output of the current smoothing section 19a (FIG. 9), and the frequency analysis sections 19c and 19e. This is a means for outputting the amplitude value and the like of each frequency component output in step 4 to the outside of the spindle controller 3. As will be described later, the external output means 44 also serves as means for outputting the output of the temperature measurement corresponding output 77 to the outside. The numerical control device 14 may be input with the machining state via the external output means 44. The output of the external output means 44 is an information processing means different from the numerical control device 14, for example, the machining state. It may be input to the information processing means for statistical processing.
The processing state corresponding processing unit 46 provided in the numerical control device 14 performs predetermined processing on the tool device 13 such as generation of an alarm or forced stop of the processing device on the processing device 13 according to the output of the grasping result of the processing state grasping unit 19. It is what you do.

The external command response on / off means 20 is means for turning on and off the excitation of the magnetic bearings 6B to 9B in the hydrostatic magnetic composite bearings 6 to 9 according to a command external to the spindle controller 3. The excitation on / off by the external command response on / off means 20 may be performed for all of the magnetic bearings 6B to 9B or only for a specific one. In the example of FIG. 1, the external command response on / off means 20 is configured such that a switch responding with a control signal is interposed in each electric circuit portion connected from the electromagnet power circuit 42 to the magnetic bearings 6B to 9B.
The external command response on / off means 20 may be provided between the power supply 41 and the electromagnet power circuit 42 as shown in FIG. 14, or between the control means 43 and the electromagnet power circuit 42 as shown in FIG. It may be provided in between so that a command to make the current zero is given to the electromagnet power circuit 42.

  The excitation on / off command generating means 45 of the numerical control device 14 gives an on / off command to the external command response on / off means 20 in accordance with the command of the machining program 50 as the machining by numerical control proceeds. In this case, for example, the excitation on / off command generating means 45 is operated by a predetermined command generated in the numerical control device 14 when a predetermined command of the machining program 50 is decoded by the numerical control device 14 or executed. The excitation on / off command is generated. The on / off command to the external command response on / off means 20 may be issued from an information processing means such as a computer other than the numerical controller 14.

FIG. 7 shows an example of control when machining is performed with the external command response on / off means 20 turned on and off. This example is an example applied when there is a finishing machining command after the rough machining command as in the machining program 50 shown in FIG. First, after the excitation is turned on (S2) by the rough machining command (S1), the spindle 4 is started (S3). In this state, the hydrostatic magnetic composite bearings 6 to 9 support the main shaft 4 with both static pressure and magnetic force.
Until a finishing machining command is issued, excitation is kept on as it is (S4). When there is a finishing processing command, excitation is turned off (S5), and the hydrostatic magnetic composite bearings 6-9 are supported only by the hydrostatic gas bearings 6A-9A. When there is a predetermined command such as the end of machining or rough machining of another part (S6), excitation is turned on (S7), and the spindle 4 is supported by both static pressure and magnetic force.

  As described above, the magnetic bearings 6B to 9B are turned off during the roughing process, and the magnetic bearings 6B to 9B are used during the finishing process, so that high efficiency can be achieved during the roughing process and high precision can be achieved during the finishing process. High-precision processing can be realized.

The countermeasure against thermal expansion of the housing 5 etc. will be mainly described with FIG. The spindle device 1 has a cooling means 71, and the cooling means 71 circulates a cooling medium path 72 such as a water jacket provided in the housing 5 and a cooling medium such as cooling water through the cooling medium path 72. And a cooling unit 73. The main shaft 4 is made of a low thermal expansion material, for example, a low thermal expansion soft magnetic material such as Invar material.
The housing 5 is provided with temperature measuring means 76, and the spindle controller 3 is provided with temperature measurement corresponding output means 77, external output means 44, storage means 79, writing means 80, and reading means 81. Further, the numerical control device 14 is provided with a cooling control means 82, a temperature correction means 83, a forced stop means 88, and an alarm means 89 as the temperature correspondence processing means 100.
The temperature measuring means 76 detects the housing temperature on the tip side of the flange 4a of the main shaft 4, and a temperature sensitive element such as a platinum resistance element or a thermocouple is used. The temperature measuring unit 76 may use a measured value of the resistance of the electromagnet coil 25 (FIG. 4) of the magnetic bearing 6.

  In this example, the temperature measurement corresponding output unit 77 includes a comparison unit 84 and a digital conversion unit 85. The comparison unit 84 compares the temperature measurement value output from the temperature measurement unit 76 with a set value serving as a threshold value, and outputs an abnormal signal when the set value is exceeded. A comparator is used. The comparing means 84 may correspond to a plurality of set values and output a plurality of stages of abnormal signals. The digital conversion means 85 is a means for converting the output of the analog signal of the temperature measurement means 76 into a digital value. When the output of the comparison means 84 is a simple binary signal, the output of the comparison means 84 is indicated by a plurality of digits. It also serves as a means for converting to a digital value. The temperature measurement corresponding output unit 77 outputs the temperature measurement value output from the digital conversion unit 85 or an abnormal signal based on the digital value. The abnormal signal of the comparison means 84 may be used as the output of the temperature measurement corresponding output means 77 as it is.

  The writing unit 80 is a unit that causes the storage unit 79 to store a digital temperature measurement value and an abnormality signal that are output from the temperature measurement corresponding output unit 77. The storage means 79 is capable of accumulating and storing these temperature measurement values and abnormal signals output one after another. The storage means 79 is composed of a magnetic disk device, other large-capacity storage devices, etc. in addition to memory elements.

The external output unit 44 is a unit that outputs each output of the temperature measurement corresponding output unit 77 to the outside of the spindle controller 3, and may be an interface including a simple output port. In this example, the external output unit 44 further reads out from the communication unit 86. Means 81 is included. The communication means 86 is means for communicating with a remote place via a communication line 87 such as a telephone line network or a data communication line network. The reading unit 81 is a unit that outputs stored data from the storage unit 79 in response to a command from the outside of the spindle controller 3, and measures the temperature during any spindle operation stored in the storage unit 81 in response to the external command. Values and error signals can be output.
In this example, the external output unit 44 is also used as an external unit for outputting the machining state grasping unit 19 shown in FIG. 1. However, the external output unit 44 is different from the processing state grasping unit 19 and the temperature measurement corresponding output unit 77. Another external output means may be provided. The writing means 80 may also serve as a means for storing the output of the machining state grasping means 19 in the storage means 79. In this case, the reading means 81 is also stored in the storage means 79 in response to an external command. It is possible to output the stored contents related to the processing state grasp result.

The means of the temperature corresponding processing means 100 provided in the numerical controller 14 will be described.
The forcible stop means 88 is means for forcibly stopping the processing apparatus 13 in response to an abnormal signal output from the temperature measurement corresponding output means 77 via the external output means 44. The alarm means 89 is a means for generating an alarm in response to an abnormal signal output from the temperature measurement corresponding output means 77 via the external output means 44. As an alarm, an alarm sound is generated, an alarm lamp is lit, and a display is displayed. Displays alarms on the device screen.

  The cooling control means 82 is a means for controlling the cooling means 71 in response to an abnormal signal output from the temperature measurement corresponding output means 77 via the external output means 44. For example, the cooling control means 73 instructs the cooling unit 73 to increase the cooling intensity. give.

The temperature correction unit 83 is a unit that controls the spindle positioning mechanism 75 in accordance with the temperature measurement value output from the temperature measurement corresponding output unit 77 via the external output unit 44. That is, the movement amount of the spindle positioning mechanism 75 is basically controlled according to the command value of the machining program, but the temperature correction means 83 uses this feed amount according to the temperature measurement value according to a predetermined temperature correction arithmetic expression. change.
In this temperature correction calculation, for example, a calculation is performed in which a change amount associated with a temperature change in the dimension (C dimension) from the spindle device mounting position P to the tool tip is added as a correction value of the spindle feed amount. The C dimension indicating the axial position of the tool tip is the dimension (A dimension) of the main shaft 4 from the tip of the tool 11 to the spindle flange 4a and the dimension of the housing 5 from the spindle device mounting position P to the spindle flange 4a ( B dimension). Accordingly, the C-dimensional thermal expansion amount is calculated from the difference between the B-dimensional housing thermal expansion amount and the A-dimensional spindle thermal expansion amount. Since the housing 5 and the main shaft 4 are not in contact with each other and there is a difference in temperature and temperature change, the temperature measuring means 76 of the housing 5 cannot measure the temperature of the main shaft 4. Further, since the spindle 5 rotates at a high speed, it is difficult to measure the temperature by providing a separate sensor. Therefore, the thermal expansion amount of the main shaft 4 may be calculated at a temperature estimated from the temperature detected by the temperature measuring means 76, or the main shaft thermal expansion amount may be ignored. For this reason, when a low thermal expansion material is used for the main shaft 4, the error of thermal expansion correction can be small.

FIG. 17 shows another embodiment of the present invention. In this embodiment, the temperature measurement corresponding output unit 77A includes a conversion unit 90 and a comparison unit 84A in the subsequent stage. Further, the temperature measurement corresponding output means 77A has a digital conversion means 85A in the input section, and a signal obtained by converting the temperature measurement value into a digital value is input to the conversion means 90. The conversion means 90 converts the temperature measurement value of the temperature measurement means 76 into the axial position of the tip end of the spindle 4 or the axial position (C dimension) of the tip of the tool 11 which is a member attached to the tip end of the spindle by a predetermined thermal displacement calculation. Convert to. The comparing means 84A compares the converted value output from the converting means 90 with a set value, and outputs an abnormal signal when the converted value exceeds the set value. The temperature measurement corresponding output unit 77A outputs the temperature measurement value output of the digital conversion unit 85A, the output of the conversion unit 90, and the abnormality signal of the comparison unit 84A.
The external output means 44 outputs the above outputs of the temperature measurement corresponding output means 77A to the outside of the spindle controller 3. Further, the writing unit 80 causes the storage unit 79 to store the above outputs of the temperature measurement corresponding output unit 77A.
The temperature correction unit 83 </ b> A performs a temperature correction calculation using the converted value output from the conversion unit 90.

Other configurations and functions in this embodiment are the same as those in the embodiment of FIG. In this embodiment, instead of comparing the converted values, the comparison means 84A may compare the temperature measurement value of the temperature measurement means 76 with the set value and output an abnormal signal as in the embodiment of FIG. Alternatively, the temperature measurement value obtained by the digital value converted by the digital conversion means 85A of the temperature measurement means 76 may be compared with a set value to output an abnormal signal.
For example, the abnormality signal is generated by comparing the temperature measurement value (or its digital conversion value) of the temperature measurement means 76 with the comparison means 84A, and the converted value output of the conversion means 90 is output to the temperature correction calculation by the temperature correction means 83A. Use.

  According to the spindle device 1 of the embodiment of FIGS. 16 and 17, even if the temperature of the spindle device 1 changes, the temperature of the spindle positioning can be corrected and the workpiece W can be machined with high accuracy. Further, when the spindle device is abnormal due to an excessive rise in the housing temperature, a signal can be output to the outside to stop the spindle device 1 or issue an alarm.

Next, the communication system will be described. As shown in FIG. 1, this spindle apparatus 1 has communication means 86 for communicating with a remote information processing means 121 and a communication line 87 such as a telephone line network in the spindle controller 3 or separately from the spindle controller 3. is doing. The communication unit 86 may serve as the external output unit 44, or may be provided as a part of the external output unit 44. The communication unit 86 may be the numerical control device 14 or a host control computer of the numerical control device 14. It may be provided in an information processing means (not shown) or the like.
The communication means 86 includes an output from the machining state grasping means 19 of the spindle device 1, current detection values from the current detection means 15 to 18, a smooth value output from the current smoothing section 19a (FIG. 9), and frequency analysis sections 19c and 19e ( Any one of the amplitude values of each frequency component output in FIGS. 10 and 11) can be communicated. The remote information processing unit 91 has a function of performing predetermined processing on the information communicated from the communication unit 86. This predetermined processing is, for example, statistical processing of the machining state, generation of a command for controlling the spindle controller 3 or the numerical control device 14, or the like.
The remote information processing means 121 has a function of giving an on / off command to the external command response on / off means 20 of the spindle controller 3. The transmission of the on / off command from the information processing means 121 to the external command response on / off means 20 is performed via the numerical control device 14 or information processing means (not shown) which is a host control computer of the numerical control device 14. Also good.
Furthermore, the communication means 86 can transmit the output of the temperature measurement corresponding output means 77 and the stored contents of the storage means 79 (FIG. 16) via the communication line 87. The remote information processing unit 121 may perform a predetermined process on the output of the temperature measurement corresponding output unit 77 communicated to give a command to the mold processing apparatus. For example, the information processing unit 121 may have the function of the temperature processing unit 100.

FIG. 20 shows a development example of a communication system. A plurality of other processing devices 102 are installed in the office 101 where the mold processing device 13 is installed, and these processing devices 13 and 102 are each an independent or a plurality of information processing means 103, 104 is connected. These information processing means 103 and 104 constitute a local area network 119 together with network components such as the web server 110, the fiber wall 111, and the router 112. This local area network 119 is connected via a communication line 116 to a remote information processing means 121 installed in a local area network of another office 113, 114 via the Internet 120 via a communication line 87. Yes.
The mold processing apparatus 13 is basically configured such that the numerical control apparatus 14 is connected to the information processing means 103 and is connected to a communication line in the local area network 119 via the information processing means 103. In combination with this, or separately from this, a communication system directly connected to the communication line in the local area network 119 from the communication means 86 provided in the numerical controller 14 or the spindle controller 3 is provided. It is also good.

It is a block diagram which shows the conceptual structure of the spindle apparatus in the metal mold | die processing apparatus concerning one Embodiment of this invention. It is a longitudinal cross-sectional side view of the spindle apparatus main body. It is a cross-sectional front view of the spindle apparatus main body. It is an expanded sectional view of a radial type hydrostatic magnetic compound bearing. It is an expanded sectional view of an axial type hydrostatic magnetic compound bearing. It is a block diagram which shows the conceptual structure of a numerical control apparatus. It is a flowchart which shows the example of excitation on / off control of the magnetic bearing in a hydrostatic magnetic compound bearing. It is a block diagram which shows the basic composition of a process state grasping means. It is a block diagram which shows the modification of a process state grasping means. It is a block diagram which shows the other modification of a process state grasping | ascertainment means. It is a block diagram which shows the further another modification of a process state grasping | ascertainment means. It is a graph which shows the example of processing state grasping by current smoothing. It is a graph which shows the example of processing state grasping by frequency analysis. This is a block of a spindle controller in which the arrangement of external command response on / off means is different. This is a block of a spindle controller in which the arrangement of external command response on / off means is further different. It is a block diagram which mainly shows the temperature measurement corresponding | compatible output means of the spindle apparatus in the metal mold | die processing apparatus. It is a block diagram of the conceptual structure of the spindle apparatus which mainly shows the modification of a temperature measurement corresponding | compatible output means. It is explanatory drawing which shows collectively the front view of the whole metal mold | die processing apparatus concerning one Embodiment of this invention, and the schematic block diagram of the control system. It is a top view of the table part of the metal mold | die processing apparatus. It is explanatory drawing which shows the example of expansion | deployment of the communication system of the metal mold | die processing apparatus.

Explanation of symbols

1 ... Spindle device
2 ... Spindle device body
3 ... Spindle controller
4 ... Spindle
5 ... Housing
6-9 ... Hydrostatic magnetic compound bearing
6A-9A ... Static pressure gas bearing
6B-9B ... Magnetic bearing
10 ... Spindle drive source
11 ... Tool
14 ... Numerical control device
15-18 ... Current detection means
19 ... Measuring state grasping means
19a ... Current smoothing section
19b, 19d, 19f ... Machining state grasping unit
19c, 19e ... Frequency analysis section
20: External command response on / off means
28, 38 ... displacement detection means
44 ... External output means 45 ... Excitation on / off command generating means 46 ... Processing state correspondence processing means 51 ... Table device 71 ... Cooling means 75 ... Spindle positioning device 76 ... Temperature measurement means 77, 77A ... Temperature measurement correspondence output means 78 ... External output Means 79 ... Storage means 80 ... Writing means 82 ... Cooling control means 83 ... Temperature correction means 86 ... Communication means 87 ... Communication line 100 ... Temperature correspondence processing means 121 ... Remote information processing means W ... Workpiece

Claims (14)

  The die processing apparatus provided with the spindle apparatus which rotates a tool, The said spindle apparatus is a die processing apparatus which supported the main axis | shaft with the static pressure magnetic compound bearing by which the static pressure gas bearing and the magnetic bearing were compounded.   In a die machining apparatus provided with a spindle device for rotating a tool, the spindle device supports a main shaft with a hydrostatic magnetic compound bearing in which a hydrostatic gas bearing and a magnetic bearing are combined. A die machining apparatus provided with current detection means for detecting an excitation current and machining state grasping means for grasping a machining state by the tool from a current detection value of the current detection means.   The machining state grasping means converts the static load of the spindle from the current smoothing unit that smoothes the current detection value of the current detection means, and the smoothed value output of the current smoothing part, and determines the machining state from the static load conversion result. The mold processing apparatus according to claim 2, further comprising a processing state grasping unit for grasping.   In the mold processing apparatus provided with the spindle device for rotating the tool, the spindle device is configured such that the main shaft is supported by a hydrostatic magnetic compound bearing in which a hydrostatic gas bearing and a magnetic bearing are combined. A die machining apparatus provided with a displacement detection means for detecting displacement and a machining state grasping means for grasping a machining state by the tool from a displacement detection value of the displacement detection means.   The machining state grasping means includes a frequency analysis unit that performs frequency analysis on the output of the current detection unit or the displacement detection unit, and a process that grasps the machining state from the amplitude of each frequency component output from the frequency analysis unit. The mold processing apparatus according to claim 2 or 4, further comprising a state grasping unit.   In a die machining apparatus having a spindle device for rotating a tool, the spindle device supports a main shaft by a hydrostatic magnetic compound bearing in which a hydrostatic gas bearing and a magnetic bearing are combined, and the hydrostatic magnetic compound bearing A die machining apparatus provided with an external command response on / off means for turning on and off excitation of the magnetic bearing in accordance with a command external to the spindle controller.   7. The die machining apparatus according to claim 6, wherein the external command for excitation on / off is a command given from a numerical controller that controls the machine part of the mold machining apparatus.   8. The die machining apparatus according to claim 7, wherein the external command for excitation on / off is a command for turning on the magnetic bearing during rough machining and turning off the magnetic bearing during finishing machining. In the mold processing apparatus provided with the spindle device for rotating the tool, the spindle device is configured such that the spindle is supported on the housing via a hydrostatic magnetic compound bearing in which a hydrostatic gas bearing and a magnetic bearing are combined. Temperature measurement means for the housing, temperature measurement corresponding output means for obtaining a predetermined output from the temperature measurement value of the temperature measurement means, and temperature correspondence processing means for performing a predetermined process from the output of the means, the temperature measurement The predetermined output of the corresponding output means is
The following 1) to 3), that is,
1). The output of the temperature measuring means,
2). A converted value obtained by converting the temperature measurement value of the temperature measurement means into the axial position of the spindle tip or the tool tip by a predetermined thermal displacement calculation, and
3). An abnormal signal obtained by comparing the measured temperature value or the converted value with a set value,
A mold processing apparatus as at least one of the above.   A cooling means for cooling the housing in which the spindle is installed is provided, and a cooling control means for controlling a cooling operation of the cooling means in response to an output of the temperature measurement corresponding output means is provided as the temperature corresponding processing means. Item 10. A mold processing apparatus according to Item 9.   A temperature correction for providing a spindle positioning mechanism for moving the housing in which the spindle is installed in the axial direction of the spindle and controlling the spindle positioning mechanism in accordance with the temperature measurement value or the converted value output from the temperature measurement corresponding output means The mold processing apparatus according to claim 9 or 10, further comprising means.   The mold processing apparatus according to any one of claims 1 to 11, wherein a spindle drive source for rotating the main shaft is a motor built in a housing in which the main shaft is installed.   The mold processing apparatus according to any one of claims 2 to 5, further comprising a communication unit that transmits a grasped content of the processing state grasping unit to a remote place via a communication line.   The mold processing apparatus according to any one of claims 9 to 12, further comprising a communication unit that transmits an output of the temperature measurement corresponding output unit to a remote place through a communication line.

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