JPS61178147A - Temperature controller - Google Patents

Abstract

PURPOSE:To prevent deformation at each section thus to realize highly accurate machining, in a temperature controller for machine tool, by controlling the temperature of heat generating sections in machine other than oil tank to referential level thus maintaining stable conditions. CONSTITUTION:Referential temperature sensors 61, 62, 63 are arranged at the positions separated from the heat producing position while an oil tank temperature sensor 20 and temperature control position temperature sensors 18, 19 are provided. Regulating means 64, 65, 66 for comparing the temperature difference between the referential temperature sensor and respective temperature sensor with setting level to produce a control signal are provided while cooling means 23 and oil supply regulating means 42, 51 for controlling the temperature of oil tank through said regulating means are provided. Consequently, the temperature at the heat generating section of machine other than the oil tank is controlled to the temperature at the referential point to maintain stable conditions thus to prevent thermal deformation at each section resulting in highly accurate and stable machining.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a temperature control device for improving the machining accuracy of machine tools, particularly machining center lathes and the like.

Conventional technology As a temperature control device for controlling the temperature of a machine using a lubricating oil unit, the well-known Japanese Patent Publication No. 46-16216 controls the oil temperature in response to the atmospheric temperature, so that the oil temperature is always maintained regardless of changes in the atmospheric temperature. There is a method that maintains a constant temperature gradient around a circulation device to eliminate distortion caused by thermal displacement around the device, and Japanese Patent Publication No. 19327-1983 controls the temperature of circulating oil by comparing it with the atmospheric temperature. There is a system that always maintains the temperature difference between the circulating oil temperature and the atmospheric temperature at a constant value regardless of changes in the atmospheric temperature.

Problems to be Solved by the Invention However, machines have multiple sources of heat generation, such as electric motors, drive systems, and main shaft bearings, each with a different temperature difference from the reference temperature. It was not possible to control the temperature sufficiently.0 Measures to solve the problem: Install a reference point temperature sensor 61 at a location away from the heat generation area.
62, 63 are installed, and the oil temperature sensor 20 of the oil tank and the temperature sensor 1819 of the temperature controlled position are installed, and the reference point temperature sensor 61, 62, 63 and each temperature sensor 18 are installed.
．． Adjustment means 64, 65, and 66 are provided to compare the temperature differences of 19.20 with a set value and output a control signal, and the cooling means 26 and oil supply amount adjustment are provided to control the temperature of the oil tank 21 by the adjustment means. Means 42.51 are provided.

Example Embodiments of the present invention will be described below based on the drawings.

In a well-known machining center, a column 2 is installed on a bed 1 from the center back, and a saddle is placed at the front so that its position can be controlled back and forth with respect to the column 2.A table is placed on the top surface of the saddle so that it can be positioned left and right. It is placed.

A spindle head 3 is provided on vertical guide surfaces on both sides of the front side of the column 2 so as to be vertically positionable, and a spindle 4 is rotatably supported by bearings in the vertical direction on the two. An annular oil passage 7 for cooling is formed on the outer periphery of the fitted oil jacket 6 between it and the spindle head 3, and is connected to an oil supply passage 8 and an oil discharge passage 9 in the spindle head 6. ing.

Further, annular channels 1 and 2 are formed on the outer periphery of the oil jacket 11 fitted with the bearing 10 on the upper end side of the center of the spindle 4, and are connected to a supply channel and a discharge channel in the spindle head 3 (not shown). . The rotation of a main motor 15 is transmitted to the main shaft 4 via a gear group 14 of an intermediate shaft 13. Since this main motor 15 becomes a heat generation source, it is fixed to the spindle head 3 via a heat insulating material 16, and a cooling annular flow path 17 is formed on the fixing surface on the spindle head side, and a supply flow (not shown) is provided. road,
Directly connected to the discharge flow path. A temperature sensor 18 that detects the temperature of the bearing 5 is screwed to the oil jacket 6, and a temperature sensor 19 that detects the temperature of the mounting portion of the main motor 15 is screwed to the mounting portion.

On the back of the Honmei, a lubricating oil tank 21 that also serves as cooling and a hydraulic tank 22 for hydraulic oil for tool changers, etc. are placed side by side, separated by heat insulation by an air layer.
is provided. The oil in the lubricating oil tank 21 is supplied to the oil jacket 6.11, the gear box of the spindle head 3, and the mounting portion of the main motor 15 by two supply pumps P1 and P2. That is, supply pump Pl
In a, the oil in the tank is sucked up from the flow path 31, the flow path 32, the throttle valve 33 where the throttle amount is first set, and the flow path 34.
The oil is sent to the flow paths 8.7 and 12 of the spindle head 6 through the flow path 53, and is supplied to the gear 1 mating surface in the gear box through the flow path 9.35 and the flow path 36.37 to the drain pump. At P3, the cooled oil is sent to the flow path 38 and the outer pipe of the double pipe cooler 39 in the hydraulic tank 22, and is then sent to the lubricating oil tank 2 through the flow path 40.
A sequence valve 41 is installed between the flow paths 31 and 32 in the middle of this circulation system, and a 2-bot 2-position electromagnetic switching valve 42 is installed in the flow path 32, and a throttle amount is first set on this discharge side. A throttle valve 43 is provided.

Then, when the solenoid 5OL1 acts and the switching valve 42 is in the 1st position 1, a part of the supplied oil is discharged and the amount of supplied oil to the bearing section is reduced. On the supply pump P2 side, the front part of the tank 21 is sucked up from the flow path 45, and the main motor 15 is pumped through the flow path 46, the throttle valve 47 where the throttle valve is first set, and the flow path 48.17. The flow path 49.
37, is similarly cooled by a double-pipe cooler 39, and then returned to the lubricating oil tank 21. Midway flow path 45 of this circulation system
．． A sequence valve 50 is provided between the flow path 46, a 2-bot 2-position electromagnetic switching valve 51, and a throttle valve 52 on the discharge side to which the throttle amount is initially set. Then, when the solenoid 5012 is activated and the switching valve 51 is in the work position, a portion of the supplied oil is discharged, and the amount of supplied oil to the main motor mounting portion is reduced. Further, a temperature sensor 20 is provided in the lubricating oil tank 21 to measure the oil temperature. Furthermore, hydraulic tank 2
2 is provided with a supply pump P4 that supplies pressure oil to operate the tool changer and the like. The freezer bag w123 has a built-in refrigerator 55, and frozen gas is sent from a cooling pipe 56 to the center pipe of a double-pipe cooler 69, cools the oil in the outer pipe, passes through a cooling pipe 57, and is blown into a condenser by a condenser fan 58. It is air cooled by 59 and has a refrigerator. At the rear of bed 1 of this machine, spindle 4,
Temperature sensors 61, 62, 63 (one piece can be shared) for temperature control reference point temperature are screwed onto the main motor 15 at a position not affected by heat in the drive system. This serves as a reference for the temperature sensor 20 for measuring the temperature of the lubricating oil tank 21, and the temperature of both sensors is determined by the base point tracking differential temperature automatic temperature regulator 64 (manufactured by Nihon Kuen-All Co., Ltd. in this example) provided in this machine. are compared, and if the set temperature difference (set to zero in this example) is no longer zero and the oil temperature side becomes higher, a signal is output to cause the refrigerator 55 to operate. The temperature sensor 62 serves as a reference for the temperature sensor 18 for measuring the temperature of the bearing 5.
, the temperatures of both sensors are compared, and if the temperature difference is greater than the set temperature difference and the temperature on the bearing 5 side is higher, a signal is output and the switching valve 42 is
Switch to the 1 position to stop oil discharge and increase the amount of oil supplied. The temperature sensor 63 serves as a reference for the temperature sensor 19 on the mounting part of the main motor 15, and the temperature of both sensors is compared using the base point tracking and wet automatic temperature controller 66 of the same machine. If so, a signal is output and the switching valve 51 is switched to the position (■) to stop the oil discharge and increase the amount of oil supplied.

Operation The operation will now be explained with reference to FIG. 4.5.6 of the control circuit.

In the machining center, the solenoids 30L1 and 30L2 of the electromagnetic switching valves 42 and 51 are initially activated and are in the position ■, sending a portion of the supplied oil to the side path, thereby supplying a small amount of oil. When machining continues in this state, the position of the bed 1 away from heat generation sources such as the electric motor 15, oil tanks 21 and 22, cutting parts, and drive system is generally affected by some heat conduction and atmospheric temperature. Although there are slight temperature changes, it maintains a relatively stable temperature. Therefore, the temperature detected by the temperature sensor 60, 61, 62 can be used as a reference point.
During operation, the temperatures detected by the temperature sensor 19 on the 5-mounting part and the temperature sensor 20 on the lubricating oil tank 21 gradually rise, and when the temperature detected by the temperature balance sensor 20 becomes high, the switch Mi93 of the refrigerator 55 is turned on and the refrigerant gas is turned on. is circulated to cool the oil returned from the flow path 38 in the double pipe cooler 39, and also cool the oil in the hydraulic tank 22. The cooled oil in the lubricating oil tank 21 is sent out from the flow path 31 by the dual supply pump Pl, passes through the flow path 32 and the throttle valve 33, cools the oil jacket 6.11 in the flow path 7.12, and cools the oil jacket 6.11 in the flow path 53. Gear group 14
However, as the operating time increases, the relationship between cooling and generated heat breaks down, and the temperature detected by the temperature sensor 18 becomes higher than the temperature detected by the standard temperature sensor 62, resulting in a temperature difference set. When the temperature difference is no longer zero, the automatic temperature regulator 65 operates solenoid solenoid solenoid 1 of the electromagnetic switching valve 42.
is demagnetized and switched to the ■ position, part of the supplied oil is stopped from being discharged, and the bearing 5.10 is sufficiently cooled by the increased amount of supplied oil.

When the temperature detected by the temperature sensor 18 falls, the automatic temperature regulator 64 is activated again, the electromagnetic switching valve 42 is switched, and the amount of cooling oil sent to the bearing portion is reduced. By repeating this process, the temperature inside the bearing 5.10 follows the reference point temperature and is maintained in a stable state. In addition, although the heat generated by the operation of the main motor 15 is prevented from being transferred by the insulating material 16 at the mounting part, it cannot be completely shut off, and the temperature detected by the temperature sensor 19 at the mounting part is the detection temperature of the reference temperature sensor 63. When the temperature rises further and the temperature difference is no longer the set temperature difference of zero, the solenoid 5O of the electromagnetic switching valve 51 is activated by the action of the automatic temperature controller 66.
L2 is demagnetized and switched to the summer position, part of the supplied oil is stopped from being discharged, and the increased amount of oil is sent to the flow path 17 to increase the cooling effect on the mounting part and lower the temperature. When the temperature detected by the temperature sensor 19 falls below the temperature detected by the reference temperature sensor 63, the automatic temperature regulator 66 switches the electromagnetic switching valve 51 again to reduce the supply of oil. By repeating this process, the temperature of the attachment part is kept stable. Furthermore, if the bearing part or the main motor mounting part becomes too cool, the operation of the refrigerator is separately stopped and the cooling of the oil tank is stopped so that the temperature rise due to oil circulation can be used to cope with the problem. Furthermore, when the main shaft is stopped, only the electric motor section is cooled at any time. In the above explanation, we mainly talked about cooling the oil, but since the main purpose is to control the temperature so that it all matches the temperature at the reference point, it is necessary to install a heater and heat the oil so that it matches the temperature at the reference point. Of course, this can also be done.

Effects As detailed above, the present invention differs from systems that control the temperature of oil circulation devices, etc. relative to atmospheric temperature, by controlling the temperature of the heat generating part of the machine to a reference point temperature in addition to the sleeve plate of the oil tank. Since the structure is maintained in a stable state, deformation of each part due to heat is prevented and stable and highly accurate machining can be realized.

[Brief explanation of the drawing]

FIG. 1 is a control circuit diagram of the present invention, FIG. 2 is a diagram showing the mounting position of a reference temperature sensor, and FIG. 3 is a partial cross-sectional view of the spindle head. Figure 4.5.6 is a control circuit diagram. 1...Ped 4...Main shaft 6.11...Oil jacket 5.10...Bearing 7.12.1
7... Annular flow path 15... Main motor 21... Lubricating oil tank 22... Hydraulic tank Pi, p2, P
4... Supply pump P3... Drain pump 18.1
9.20...Temperature sensor 42Aε1...Solenoid switching valve 61.62.63...Temperature sensor for reference point
64.65.66...Base point tracking differential temperature automatic temperature controller patent applicant Okuma Iron Works Co., Ltd. Ma
Tsuri Okaya Koki Co., Ltd. Figure 4 Figure 5

Claims (3)

[Claims] (1) A reference point temperature sensor is installed in the machine body at a location far from heat generation sources such as the electric motor, main shaft, drive system, etc. and where temperature changes are small, or in the atmosphere, and a first sensor is installed to detect the temperature of the oil in the oil tank.
A temperature sensor is provided, and one or more second temperature sensors are provided at one or more temperature-controlled positions of the machine to detect the temperature at that position, and the temperature of the reference point temperature sensor and the temperature of the first temperature sensor are a first adjustment means configured to detect a temperature difference between the reference point temperature sensor and the second temperature sensor and output a control signal; An adjustment means is provided corresponding to the second temperature sensor, a temperature control means for oil in the tank whose operation is controlled by the first adjustment means is provided, and the temperature control position is controlled by the second adjustment means. A means for adjusting the flow rate of the lubricating/heating/cooling oil supplied to the heating/cooling oil is provided corresponding to the heated position,
A temperature control device characterized by independently controlling the temperature of an oil tank and a temperature-controlled position so as to follow a reference point temperature. (2) The temperature control device according to claim 1, wherein the temperature control means for the oil in the tank is a cooling means. (3) The temperature control device according to claim 1 or 2, wherein the temperature control means for the oil in the tank is a heating means.