JPH11262840A - Rapid warm-up machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rapid warm-up machine tool which requires a shorter time for warm-up operation than a machine tool using conventional technology. SOLUTION: One embodiment of a rapid warm-up machine tool is a grinder which includes a grinding wheel spindle 2 for holding and rotationally driving a grinding wheel 1 and a built-in motor 3 for rotationally driving the grinding wheel spindle 2 as an axis of rotation. It is furnished with a rotation load nozzle 6 from which grinding fluid is sprayed to the grinding wheel 1 during warm-up operation to give rotation load to the grinding wheel spindle 2, whereby the load of the built-in motor 3 is increased to accelerate the temperature rise thereof. During warm-up operation, cooling fluid is not supplied to a water jacket 5 and so the temperature rise of the built-in motor 3 is further accelerated. As a result, the temperature rise of the grinding wheel spindle 2 is accelerated to complete the warm-up operation in a short time. The completion of the warm-up operation when the grinding wheel spindle 2 is at a predetermined temperature is detected by a temperature sensor 7 provided on the built-in motor 3 and an operator is informed thereof by a controller 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the technical field of machine tools having a built-in motor built into a spindle.

[0002]

2. Description of the Related Art A grinding machine will be described as an example of a machine tool. In a grinding machine equipped with a built-in motor on the grinding wheel shaft, in order to precisely grind the work, the grinding wheel shaft is warmed up to approximately the same temperature as during normal operation, and the grinding wheel shaft is thermally expanded. It is necessary to stabilize the dimension in the axial direction. In the conventional warming-up operation of a grinding machine, the grinding wheel shaft is rotated without grinding the workpiece while turning the pumps for hydraulic oil, lubricating oil, coolant and grinding fluid, etc. Spending on. The time spent in warm-up operation is determined empirically, and no particular effort has been made to reduce the time spent in warm-up operation.
Further, there is no means for knowing the completion of the warm-up operation.

[0003]

In the warming-up operation of the above-mentioned conventional grinding machine, if the warming-up operation is performed for a certain period of time determined empirically, chattering occurs and grinding accuracy is reduced. The warm-up operation is performed only based on the empirical rule that the problem described above is avoided. Therefore, in order to perform normal grinding from the first workpiece at the beginning of grinding, it is necessary to perform warm-up operation with a margin, which increases the time required for warm-up operation. Occurs. In addition, when the operation is resumed after being temporarily stopped, it is difficult to determine how much time is required for the warm-up operation. In many cases, there is a disadvantage that an unnecessarily long time is spent for the warm-up operation.

[0004] These inconveniences are not limited to the grinding machines exemplified above, but occur in general for machine tools having a built-in motor built into the main shaft. Accordingly, an object of the present invention is to provide a rapid warm-up machine tool that requires less time for warm-up operation than a conventional machine tool.

[0005]

Means for Solving the Problems and Their Functions and Effects In order to solve the above problems, the inventors have invented the following means. (First Means) A first means of the present invention is a rapid warm-up machine tool according to the first aspect. In this means, when the warm-up operation of the rapid warm-up machine tool is started, the temperature rise of the spindle incorporating the built-in motor is promoted by the spindle temperature raising means,
The spindle temperature rises in a short time. When the temperature of the spindle rises to a predetermined temperature close to the temperature during steady operation, the temperature detecting means directly or indirectly detects the temperature of the spindle, and confirms that the spindle temperature has reached the predetermined temperature. Emit a signal that indicates Then, the control means controls the spindle temperature raising means based on the signal from the temperature detection means and stops its operation, so that the spindle temperature does not exceed the spindle temperature during steady operation and is close to the spindle temperature during steady operation. And stabilized.

Therefore, according to the present invention, the spindle temperature can be raised to a temperature close to the temperature at the time of steady operation in a short time, so that the warm-up operation requires less time than the conventional machine tool. There is an effect that a warm-up machine tool can be provided. (Second Means) A second means of the present invention is a rapid warm-up machine tool according to claim 2.

In this means, since the spindle temperature raising means is a rotational load applying means for applying a rotational load to the spindle, a rotational load is applied to the built-in motor more than during a normal operation, and the built-in motor is rotated more than during a normal operation. Fever. As a result, the main shaft also serving as the rotating shaft of the built-in motor is heated, and the main shaft temperature rises more rapidly than in a normal warm-up operation. Therefore, in the present means, it is only necessary to provide a rotating load applying means as the main shaft temperature raising means, and a heating means for raising the temperature of the main shaft is not separately required besides the built-in motor itself. The rapid warm-up machine tool can be implemented.

Therefore, according to this means, in addition to the effect of the above-described first means, there is an effect that the device configuration becomes relatively simple. (Third Means) A third means of the present invention is a rapid warming machine tool according to claim 3, that is, a rapid warming grinder.

In this means, the machine tool is a grinder, the main shaft is a grindstone shaft for rotating the grindstone, and the rotating load applying means has a rotating load nozzle for spraying a grinding fluid on the grindstone. In other words, in the rapid warm-up grinding machine of the present means, the rotating load applying means does not require a brake device or the like, and the rotating load nozzle simply sprays the grinding fluid on the grindstone, and the device which controls the supply of the grinding fluid to the nozzle. Only need to be provided. Therefore, not only is the device configuration simple, but also unlike the brake device, there is no consumable part such as a brake shoe, so that maintenance is easy.

Therefore, according to this means, in addition to the effect of the above-described second means, there is an effect that not only the device configuration is further simplified, but also the maintenance is easy. (Fourth Means) A fourth means of the present invention is a rapid warming-up machine tool according to claim 4. The rapid warm-up machine tool of this means has a water jacket disposed around a built-in motor and filled with a coolant, and a coolant supply device for supplying the coolant to the water jacket. In this means, the control means controls the coolant supply device based on the signal from the temperature detection means, does not operate the coolant supply device during the warm-up operation, and at least the temperature of the built-in motor is reduced. While the temperature is below the predetermined temperature, the cooling liquid is not supplied to the water jacket. Then, since the built-in motor is not cooled by the coolant, the temperature of the built-in motor increases, and as a result, the heat flow transmitted from the built-in motor to the main shaft increases, and the main shaft is quickly heated.

Therefore, in this means, the control means for controlling the coolant supply device serves as both the spindle temperature raising means and the control means for controlling the spindle temperature raising means, and additionally requires the spindle temperature raising means and the control means separately. Therefore, the device configuration becomes very simple. Alternatively, when the spindle temperature raising means is separately provided, the spindle temperature rises more quickly due to a synergistic effect, and the time required for the warm-up operation is further reduced.

Therefore, according to this means, in addition to the effect of the above-mentioned first means, there is an effect that either the apparatus configuration becomes very simple or the warm-up operation time is further shortened. (Fifth Means) A fifth means of the present invention is a rapid warm-up machine tool according to the fifth aspect. Since the present means has the notifying means for notifying the completion of the warm-up operation based on the signal from the temperature detecting means, it is possible to immediately shift to the normal operation after the completion of the warm-up operation, and no time is wasted. .

Therefore, according to this means, in addition to the effect of the above-described first means, there is an effect that, after the completion of the warm-up operation, the normal operation can be promptly shifted.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the rapid warming machine tool of the present invention will be clearly and fully described in the following examples so that those skilled in the art can understand the present invention. Embodiment 1 (Structure of Embodiment 1) As shown in FIG. 1, a rapid warm-up machine tool according to Embodiment 1 of the present invention includes a grindstone shaft 2 serving as a main shaft holding a grindstone 1 at one end, and a grindstone. A built-in motor 3 for rotating and driving the grinding wheel shaft 2 using the shaft 2 as a rotation axis;
And a housing 4 for supporting the built-in motor 3 by rotatably supporting the bearings 21 and 22.

A water jacket 5 filled with a cooling liquid is provided around the built-in motor 3. A water jacket 5 is provided near the housing 4 through a suction port 51 and a discharge port 52. Is provided with a cooling liquid supply device for circulating and supplying a cooling liquid to the cooling medium. The cooling liquid supply device includes a pump 54 for pumping the cooling liquid,
It comprises a motor 53 for driving a coolant pump 54, a coolant tank 55 and a cooling device 56.

The grinding machine of this embodiment further includes a spindle temperature raising means for accelerating the temperature rise of the grinding wheel shaft 2 as a spindle during a warm-up operation, and a temperature detecting means for indirectly detecting the temperature of the grinding wheel shaft 2. And a control means for controlling the spindle temperature raising means based on a signal from the temperature detection means. The main spindle temperature raising means includes a rotary load nozzle 6 as a rotary load applying means for applying a rotary load to the grinding wheel shaft 2, an electromagnetic valve 61 for supplying a grinding fluid to the rotary load nozzle 6, a grinding fluid pump 64, a motor 63. And a grinding fluid tank 65 are provided. The rotation load nozzle 6 has a function of spraying a grinding liquid on the grindstone 1 to increase the rotation load of the grindstone 1.
The grinding fluid sprayed on the grinding wheel 1 is collected into a grinding fluid tank 65 from a grinding fluid reservoir 66 formed below the grinding wheel 1.

As shown in FIG. 2, the rotating load nozzle 6
Two devices are provided near the outer peripheral surface of the grindstone 1, and a large amount of grinding fluid is sprayed substantially perpendicularly to the outer peripheral surface of the grindstone 1. The grindstone 1 rotating at high speed receives fluid resistance due to a large amount of grinding fluid on the outer peripheral surface, and as a result, receives a load torque in a direction that hinders rotation. Here, the rapid warm-up grinding machine of the present embodiment is configured to separate the work W
It also has a grinding fluid nozzle 9 similar to an ordinary grinding machine that sprays a grinding fluid on the surface to be ground. Although the grinding fluid nozzle 9 is not shown in FIG. 1 for simplification of the drawing,
A grinding fluid is supplied from a grinding fluid pump 64 (see FIG. 1) via an electromagnetic valve (not shown). The grinding fluid sprayed from the grinding fluid nozzle 9 onto the grindstone 1 and the work W also flows from the grinding fluid reservoir 66 formed under the grindstone 1 into the grinding fluid tank 6.
Collected to 5. During the warm-up operation, the workpiece W and the grindstone 1 are separated from each other, and the grinding fluid is not supplied to the grinding fluid nozzle 9.

As shown in FIG. 1 again, the temperature detecting means is a temperature sensor 7 which is a thermistor incorporated in the stator of the built-in motor 3, and an output signal of the temperature sensor 7 is A / D converted and controlled. A / D transmitted to device 8
An adapter 71 is provided. The temperature sensor 7 does not directly measure the temperature of the grinding wheel shaft 2, but indirectly measures the temperature of the grinding wheel shaft 2 by measuring the temperature of the stator of the built-in motor 3.

As the control means, a programmable
A control device 8 as a sequence controller is provided. The control device 8 controls the main shaft temperature raising means based on a signal from the temperature sensor 7 as a temperature detecting means, and also controls the cooling liquid supply device. Further, the control device 8 is provided with a warm-up completion lamp (see FIG. 3) as a notifying means for notifying the operator of the completion of the warm-up operation based on a signal from the temperature sensor 7.

The controller 8 may be configured to notify the operator of the completion of the warm-up operation by a warm-up completion lamp to the operator, and to automatically start the work of grinding the work W. . (Effects of Embodiment 1) The rapid warm-up grinder of this embodiment
With the above configuration, the following operation and effect can be obtained.

The control device 8 controls the warming-up operation of the grinding machine by the logic as shown in the ladder circuit diagram of FIG. That is, when the operator presses the start switch to instruct the start of the warm-up operation, power is supplied to close the relay of the solenoid coil SOL1, and power is supplied to the built-in motor 3, which is a grinding wheel shaft motor, to rotate the grinding wheel shaft 2. . With it,
Since the sensor signal indicating that the predetermined temperature has been reached from the temperature sensor 7 has not yet arrived with the relay of the grinding wheel shaft motor closed, the motor 63 that drives the grinding fluid pump 64
And the electromagnetic valve 61 (see FIG. 1), and the grinding fluid (coolant) is pumped to the rotary load nozzle 6. Even if the relay of the grinding wheel motor is closed, since the sensor signal from the temperature sensor 7 indicating that the predetermined temperature has been reached has not yet arrived, the coolant pump 54 for circulating the coolant through the water jacket 5 Is not driven yet. As a result, the load torque of the built-in motor 3 increases, and the temperature of the built-in motor 3 rapidly rises because the built-in motor 3 is not cooled by the coolant. Then, the built-in
The heat transfer from the motor 3 to the grinding wheel shaft 2 becomes active, and the temperature of the grinding wheel shaft 2 rapidly rises during the warm-up operation.

The warm-up operation is sufficiently performed, and a sensor signal indicating that a predetermined temperature has been reached from the temperature sensor 7 is output from the control device 8.
Is supplied to the warm-up completion lamp, the warm-up completion lamp is turned on, and the operator is notified that the warm-up operation has been completed. At the same time, a motor 5 that drives a coolant pump 54 that circulates coolant through the water jacket 5
3 and the cooling of the built-in motor 3 by the coolant is started. Further, the power supply to the motor 63 for driving the grinding fluid pump 64 and the electromagnetic valve 61 is cut off, and the supply of the coolant to the rotary load nozzle 6 is stopped. Then, although not explicitly shown in FIG. 3 for simplifying the logic, the grinding fluid is supplied to the grinding fluid nozzle 9. As a result, the built-in motor 3 enters a normal operation state, and the temperature of the grinding wheel shaft 2 has already been sufficiently raised.
Grinding becomes possible.

It should be noted that, during the warm-up operation and the normal operation, if the stop switch is pressed, all the motors 2, 5,
3, 63 are stopped, and the operation of the rapid warming grinder of this embodiment is stopped. The above operation can be described with reference to a flowchart as shown in FIG.

That is, when the start switch is turned on,
In step S1, the built-in motor 3, which is a grindstone motor, is started, and a warm-up operation is started. Next, step S
In step 2, the control device 8 receives the temperature signal from the temperature sensor 7, and then in a determination step S3, determines whether the temperature signal is equal to or higher than a predetermined temperature serving as a reference for determining completion of the warm-up operation. Is determined. If it is determined that the temperature signal is not equal to or more than the predetermined value, the process proceeds to step S4, the solenoid coil SOL1 is turned on, and the grinding fluid pump 64 for pumping the coolant to the rotary load nozzle 6 is driven.

At this point, since the coolant pump 54 for circulating the coolant through the water jacket 5 has not been started, the forced cooling of the built-in motor 3 by the water jacket 5 has not been performed. Therefore, the load torque of the built-in motor 3 is increased by the rotary load nozzle 6, and the built-in motor 3 is not forcedly cooled by the coolant.
Temperature rises rapidly, and the grinding wheel shaft 2 rapidly rises in temperature. As long as the temperature signal from the temperature sensor 7 is not more than a predetermined value,
The routine of steps S2 to S4 is repeated, and the warm-up operation is continued. (However, although not explicitly shown in FIG. 4 for simplification of the logic, if the stop switch is pressed even during the warm-up operation, a step for stopping the built-in motor 3 and the grinding fluid pump 64 is provided. However, it is naturally possible to stop during the warm-up operation.) However, if the temperature signal from the temperature sensor 7 has reached a predetermined value or more and it is determined in step S3 that the warm-up operation has been completed, The control of the control device 8 proceeds to steps S5 to S8. That is, the warm-up completion lamp for notifying the operator of the completion of the warm-up operation is turned on in step S5, and the motor 53 for driving the coolant pump 54 for pumping the coolant to the water jacket 5 is started in step S6. . Further, in step S7, the relay of the solenoid coil SOL1 opens,
The supply of the grinding fluid to the rotating load nozzle 6 is stopped, and the grinding fluid is supplied to the grinding fluid nozzle 9. Further, in step S8, it is determined whether or not the stop switch is pressed. Unless the stop switch is pressed, step S2 is performed.
The routine of S3 to S3 is repeated, and the normal operation is continued.

Here, when the stop switch is pressed and the determination is made in step S8, the control of the control device 8 proceeds to steps S9 and S10, and the rapid warm-up grinding machine of this embodiment stops the operation. Stop. That is, the built-in motor 3, which is a grindstone motor, the motor 53 for driving the coolant pump 54, and the pump for pumping the grinding fluid to the grinding fluid nozzle 9 are stopped, and the operation is stopped.

For the purpose of confirming the effect of the rapid warm-up grinding machine of this embodiment, the inventors carried out a comparative evaluation test. As a result, as shown in FIG. It was confirmed that there was an extremely high effect in shortening the time. That is, as in the present embodiment, the rotating load nozzle 6 is
In the case where the cooling liquid control of the jacket 5 is performed (（), the temperature reached 65 ° C. in which it was determined that the warm-up operation was completed in only 8 minutes. Thereafter, the supply of the grinding fluid to the rotating load nozzle 6 is stopped, and the water jacket 5 is stopped.
Since the coolant is supplied to
After about minutes, the temperature is stable around 65 ° C.

On the other hand, as another embodiment, the rotating load nozzle 6
If only the operation of (1) is performed and the circulation of the coolant to the water jacket 5 is also performed during the warm-up operation (■), it takes 13 minutes to reach the determination temperature of 65 ° C. . When the operation of the rotary load nozzle 6 was continued even when the temperature reached 65 ° C., the temperature signal of the temperature sensor 7 was stabilized at a temperature slightly higher than 70 ° C. when the warm-up operation was performed for nearly 20 minutes.

Finally, when the coolant is circulated to the water jacket 5 even during the warming-up operation, and the same warming-up operation as in the related art without operating the rotary load nozzle 6 is performed (◆), the temperature reaches 65 ° C. It took 30 minutes to stabilize. The inventors have also set the pause time for the purpose of examining how long it takes to complete the warm-up operation when the rapid warm-up grinding machine of the present embodiment is temporarily stopped and then restarted. For 3 minutes, 5 minutes, 10 minutes, 30 minutes,
The test was carried out by changing the time to 12 hours. As a result, in the case of the present embodiment having the control of the cooling fluid for the rotary load nozzle 6 and the water jacket 5, the warm-up operation was completed in 5 to 8 minutes. On the other hand, as another embodiment, the rotational load nozzle 6
If only the operation of (1) is performed and the circulation of the coolant to the water jacket 5 is also performed during the warm-up operation, 7 to
The warm-up operation was completed in 13 minutes. In each case, it was confirmed that there was an effect that the warm-up operation time was significantly reduced as compared with the conventional grinding machine which took 30 minutes for the warm-up operation.

As described in detail above, the rapid warm-up grinding machine as the rapid warm-up machine tool of the present embodiment has the following (1) to (1).
There are three effects (3). (1) During the warm-up operation, the load torque applied to the built-in motor 3 by the rotary load nozzle 6 increases, so the heat generation of the built-in motor 3 increases and the temperature rises rapidly, and the temperature of the grinding wheel shaft 2 also rises. Is accelerated and the time required for the warm-up operation is reduced. (2) During the warm-up operation, since the forced cooling by the water jacket 5 is not performed, the temperature of the built-in motor 3 rises more rapidly, and the temperature of the grindstone shaft 2 is also accelerated. Time is further reduced. (3) The completion of the warm-up operation is notified to the worker by the warm-up completion lamp, and the operation is automatically switched from the warm-up operation to the normal operation. Therefore, the warm-up operation does not require extra time, and is promptly performed. It becomes possible to start the grinding operation.

(Various Modifications of Embodiment 1) As a modification of this embodiment, instead of the rotary load nozzle 6, the grinding wheel shaft 2
May be equipped with a brake device such as a disc brake or a powder brake that applies an appropriate rotational load to the vehicle. Alternatively, the power consumption of the built-in motor 3 is increased by repeating the acceleration / deceleration of the grinding wheel shaft 2 or rotating the grinding wheel shaft 2 at a rotation speed higher than the rotation speed in normal operation within a safe limit. The temperature rise of the motor 3 may be promoted. Further, the power conversion rate of the built-in motor 3 may be reduced, such as by changing the switching frequency of the drive circuit of the built-in motor 3, to increase the power consumption, and to promote the temperature rise of the built-in motor 3. As described above, by using the spindle temperature raising means for changing the operation state of the built-in motor 3 to promote the heat generation of the built-in motor 3, the rotation load nozzle 6
As described above, a relatively large-scale device is not required, and only the controller of the built-in motor 3 needs to be modified. Therefore, there is an additional effect that a rise in cost is reduced.

As another modified embodiment, a heater for heating and raising the temperature of the cooling liquid is provided to heat the cooling liquid sent to the water jacket 5, and the built-in motor 3 is heated and raised with the cooling liquid in a manner opposite to the usual case. Configurations can also be taken.
According to this modification, the time required for the warm-up operation can be further reduced. Note that a modification in which the temperature sensor 7 is replaced with a simpler and less expensive bimetal can be implemented. According to this modification, the cost can be reduced somewhat compared to the first embodiment.

Conversely, if the temperature sensor 7 is attached to the grindstone shaft 2 itself to directly detect the temperature of the grindstone shaft 2,
The completion of the warm-up operation is determined more accurately. In addition, a temperature sensor for detecting the temperature of coolant, grinding fluid, lubricating oil, etc. is provided, and more detailed temperature information of the rapid warm-up grinding machine is provided to the control device 8 for more advanced control rules such as fuzzy control. , The temperature of the rapid warming grinder may be controlled.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of a rapid warm-up grinding machine as a first embodiment.

FIG. 2 is a schematic diagram illustrating a grindstone, a rotating load nozzle, and the like according to the first embodiment.

FIG. 3 is a ladder circuit diagram illustrating control logic of the control device according to the first embodiment.

FIG. 4 is a flowchart illustrating control logic of the control device according to the first embodiment.

FIG. 5 is a graph showing the results of a comparative evaluation test of Example 1.

[Description of Signs] 1: Grinding wheel 2: Grinding wheel shaft (as main shaft) 21, 2
2: Bearing 3: Built-in motor 4: Housing 5: Water jacket 51: Suction port 52: Drain port 53: Motor 54: Coolant pump 55: Coolant tank 56: Cooling device 6: Rotary load nozzle 61: Solenoid valve 63: motor 64: grinding fluid pump 65: grinding fluid tank 66: grinding fluid reservoir 7: temperature sensor (thermistor) 71: A / D adapter 8: control device (programmable sequence controller) 9: grinding fluid nozzle W: work

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Ogura 1-1-1, Asahi-cho, Kariya-shi, Aichi Toyota Machine Works Co., Ltd. (72) Inventor Hideki 1-1-1, Asahi-cho, Kariya-shi, Aichi Toyoda Machine Inside the corporation

Claims (5)

[Claims] 1. A spindle for holding and rotating a tool or a work at one end, a built-in motor for rotating the spindle with the spindle as a rotation axis, and a housing for rotatably supporting the spindle and holding the built-in motor. A spindle temperature raising means for promoting the temperature rise of the spindle during a warm-up operation of the machine tool; a temperature detection means for detecting a temperature of the spindle; and a signal from the temperature detection means. Control means for controlling the spindle temperature raising means on the basis of the main shaft temperature raising means. 2. The rapid warm-up machine tool according to claim 1, wherein said spindle temperature raising means is a rotary load applying means for applying a rotational load to said spindle. 3. The machine tool is a grinder, the main shaft is a grindstone shaft for driving a grindstone, and the rotating load applying means has a rotating load nozzle for spraying a grinding fluid on the grindstone. Item 3. The rapid warm-up machine tool according to Item 2. 4. A water jacket disposed around the built-in motor and filled with a coolant, and a coolant supply device for supplying the coolant to the water jacket, wherein the control means includes: 2. The rapid warm-up machine tool according to claim 1, wherein said cooling liquid supply device is controlled based on a signal from said temperature detecting means. 5. A notifying means for notifying completion of the warm-up operation based on a signal from the temperature detecting means.
The rapid warm-up machine tool as described.