JPS60199600A - Operating method of machine tool - Google Patents

Abstract

PURPOSE:To perform stable operation with less energy consumption in the stage of rotating the flywheel of a punch press machine via a hydraulic clutch brake by holding the temp. of the solenoid valve itself which controls the clutch brake. CONSTITUTION:Working operation is executed by subjecting a hydraulic clutch brake 2 to on-off control by a solenoid valve 6 in the stage of rotating a flywheel 3 of a punch press machine by a motor 4, transmitting the revolution thereof via the clutch brake 2 to a crank shaft to move upward and downward a ram and the punch and performing working such as punching. The valve 6 is heated and held to and at the set temp. of 40 deg.C by a heater attached thereto prior to driving of the motor 4 and thereafter the driving motor 4 is run to rotate the flywheel 3 so as to make punch operation. The stable operation is assured without delay in the timing of the clutch brake even in a winter time or in extremely cold area and the need for the energy required for heating and holding of hydraulic fluid is eliminated.

Description

[Detailed description of the invention] The present invention relates to a method of operating a machine tool.

There are many types of machine tools that connect the power source and material processing tools or material feeding means with hydraulic clutches and brakes, and control the clutches and brakes with solenoid valves to perform machining operations. The accuracy of the critical timing of the clutches and brakes may affect the machining accuracy or the smooth operation of the machine tool.

For example, in a punch press machine, the rotation of the flywheel is intermittently transmitted to the crankshaft via a hydraulic clutch and brake, and the ram and punch are moved up and down to form holes.
The important timing of the clutches and brakes must be accurate to the millisecond, and the fact that the above-mentioned entry timing shifts by the millisecond in a punch press machine is
This causes the crankshaft to deviate from the top dead center, forcing the operation to stop. Particularly in recent years, there has been an increase in the number of cases in which machine tools such as the above punch presses are used in automated warehouses and in combination with other machine tools to create so-called FMS (flexible manufacturing systems). Since stopping the operation of one machine tool leads to stopping the operation of the entire system, the occurrence of the above-mentioned troubles must be prevented even more frequently.

Therefore, the inventor of this invention took into account the above facts.

As a result of intensive research, we have found that, except in cases of continuous trouble caused by wear of the clutch or brake,
Discrepancies in the timing of applying the brakes are caused by the clutch,
It was found that this phenomenon was not caused by changes in the operating speed of the brake itself, but was caused mostly by changes in the switching speed of the solenoid valves that control the clutch and brake, and furthermore, the switching speed of the solenoid valves was They discovered that this recognition is based on changes in the viscosity of the hydraulic fluid due to changes in outside temperature.

Based on the above research results, attempts were made to heat the hydraulic oil inside the oil tank to a constant temperature and keep it warm.
It was found that this method was not a practical solution because it required a large amount of energy to keep all the hydraulic oil in the oil tank heated and kept warm, and it was also highly dangerous.

Therefore, as a result of further research, this invention was arrived at. By operating the solenoid valve itself while keeping it warm, it consumes less energy and successfully prevents the occurrence of the above troubles. .

Hereinafter, an example implemented in a punch press machine will be described based on the drawings.

That is, Fig. 1 is a side view of the drive system portion of the punch press machine, and Fig. 2 is a longitudinal cross-sectional view of the brake (2) attached to the crankshaft (11).

In this example, the machine tool is a punch press machine.

As the hydraulic clutch and hydraulic brake, we use a ``wet type, hydraulic, multi-disc clutch and brake combination'' made by West German company Ortringhaus, which combines both. In Fig. 1, (3) is a flywheel, (4) is a drive motor connected to the flywheel (3) and a belt (5), and (G) is a solenoid valve for controlling the clutch/brake. It is an accumulator.

The structure of the clutch/brake (2) will be described below, but it goes without saying that other clutches and brakes may be used.

That is, this hydraulic clutch/brake (2) has a clutch part (8) on the side connected to the flywheel (3), and a brake part (9) on the side connected to the outer frame (g).
A bearing (11) is interposed between the clutch side housing (8a) and the brake side housing (9a), and an outer plate (1
2) The hub (14) (13) is key-fixed to the crankshaft (1) and is provided with inner plates (15) and (16). A piston body (18) is provided in the intermediate part of the hub C14), which is always biased in the direction of arrow A, that is, in the braking direction, by a spring (17). When it moves back and forth by the hydraulic pressure introduced through the installed oil passage (19),
The front and rear surfaces of the piston body (18) are connected to the inner plate (15).
) or (1) to engage the clutch (8), brake (
9) is selectively entered. In other words,
When hydraulic pressure is applied, the piston body Cl8) is activated by the spring C17.
), the clutch (8) is engaged, and when the hydraulic pressure disappears, the piston body (18) is moved by the spring (17) and the brake (9) is activated.

Next, the solenoid (21) shown in FIG.
is in the right position, oil returns from the oil passage (19) and flows to the tank via the boat (5), and the clutch/brake (2) is operated by the brake (9) by the action of the spring (17). When the side is activated, the solenoid (21) is energized, and the spool (22) is in the left position in Figure 5, the oil flows from the boat (8) to the clutch/brake (2) and brake (9). The clutch (
8) are connected in a working state.

In addition, since the punch press machine of this example uses a two-way switching valve with splinter scratches ≥ W, the switching speed is faster due to the shorter stroke than when using a three-way switching valve. As the heat rate becomes higher, the spring (17) switches to the direction in which the brake (9) is activated even in the event of a power outage, which has the advantage of preventing the punch from continuing to punch uncontrollably. It is not limited to switching valves.

Then, the solenoid valve (6J valve body (2
3) The following heater device (24) is fitted onto the top.

6 heaters on the left and right inside the C25) (260 calorific value 900
) is buried, and a thermocouple (27) for temperature detection is installed on the top.
is buried, and the thermocouple (27) and heater (2
6) is connected to a temperature controller (not shown), so that the heater (26) and the valve body (23) are always kept at a temperature of 40 degrees centigrade. The set temperature of 40 degrees centigrade is the temperature at which the viscosity of the oil reaches its optimum value in terms of the kinematic viscosity index.

In addition, a heater device f having the same structure as the heater device (24) described above is also provided.
Fj (28) is attached to the holding frame (2) of the solenoid (21).
9) may be additionally provided around (Fig. 5).

The punch press according to this embodiment is constructed as described above, and is started and operated as follows.

In other words, in winter or in cold regions where the difference between the outside temperature and the above-mentioned optimum temperature (40 degrees Celsius) is greatest, for the reasons mentioned at the beginning, the timing of clutches and brakes tends to be delayed, especially when starting. Disconnection frequently occurs, leading to the trouble mentioned at the beginning, but even under the above conditions, the heater device C24) (28) rotates the drive motor (4) and enters steady punch operation. Turn on the switch and set the solenoid valve (6) itself at the set temperature (4
The energy required to raise the temperature is extremely small and takes only 2 to 3 minutes at most). Even after turning (4) and entering steady punch operation, the important timing of the clutch/brake (2) was performed perfectly normally, and there was no problem with the top dead center being off.

In other words, qualitatively analyzing this, under the above-mentioned conditions, the viscosity of the oil in the valve body (6) increases due to the low temperature outside air, which increases the movement resistance of the stool [22] and increases the spool. (22) It is thought that the flow rate of the oil flowing through the gap between the valves decreased and the timing of the clutch and brakes were therefore delayed. However, the heater device (24) was installed to maintain the valve body temperature at a constant temperature of 40°C. The oil flowing into the valve body (23) has a much smaller heat capacity than the main body (23), so the oil flowing into the valve body (23) is immediately raised to the appropriate temperature (40 degrees) by the main body. The increased temperature and reduced viscosity reduces the movement resistance of the spool (22) and increases the flow rate of the oil in the valve (6), thus increasing the flow rate of the oil in the clutch-brake (2).
The supply of oil to the clutch/brake (2) and the discharge of oil from the clutch/brake (2) are performed almost simultaneously with the activation timing of the solenoid (21) and the recovery timing due to the elasticity of the spring (31). )
The operation timing is delayed (it is considered to be performed normally).

In the solenoid valve (6) of the above embodiment, oil also flows through the moving cylinder (33) of the core (32) moved by the solenoid (21), and as the core moves, oil flows before and after the core. The mutual communication between the two is carried out through the slit groove (32a) formed on the side surface of the core, so the moving speed of the core (32) is also thought to change depending on the fluctuation of the viscosity of the oil. By maintaining the frame (29) at a constant optimum temperature by the heater device (28) around the core (29), the moving speed of the core (32) is also kept constant and the clutch
The important timing of braking can be better kept constant.

Furthermore, in the above-mentioned type of valve, based on the above-mentioned analysis, it was found that it was also effective to perform the following operations, especially at the time of start-up.In other words, the solenoid (21) itself generates heat if it continues to be energized. In addition to the temperature raising operation by the heater devices (24) and (28), only at the time of starting, the solenoid (21) is continuously energized, and the cylinder (3
The temperature of the oil in the frame (29) is raised directly from the inside of the frame (29), and by performing this operation, the warm-up time (2
(~3 minutes) could be further shortened.

In addition, when performing the above operation, the clutch (8) side of the clutch/brake (2) is activated by excitation of the solenoid.
Therefore, in order to prevent unexpected punch operation, an interlock is set between the end of continuous excitation of solenoid C21) and the start of rotation of the drive motor (4) in the startup program of the punch press machine. In particular, the drive motor (4) is not driven during the warm-up operation.

Further, although the above embodiments were applied to a punch press machine, the present invention can be applied to any machine tool equipped with a hydraulic clutch or hydraulic brake and a solenoid valve for controlling the clutch or brake. Not only can the method be implemented, but also the operating timing of the hydraulic clutch or hydraulic brake in the machine tool can be kept constant regardless of fluctuations in outside temperature or the like.

In any case, as is clear from the above explanation, the method of the present invention for operating the solenoid valve for controlling a hydraulic clutch or hydraulic brake while keeping it warm,
The important timing of the clutch and brake was always constant, and therefore, the machine tool was able to achieve high machining accuracy and trouble-free and smooth operation. In addition, since the solenoid valve itself is only kept warm, energy consumption is extremely small even if the method of the present invention is carried out continuously while the machine tool is in operation, and there is no risk of fire etc., making it highly safe. There are also advantages.

[Brief explanation of drawings]

Figure 1 is a side view of the drive system of the punch press machine, Figure 2 is a longitudinal sectional view of the clutch/brake attached to the crankshaft, Figure 3 is a side view of the solenoid valve, and Figure 4 is a front view of the same. FIG. 5 is a longitudinal sectional view of the same. (2)...Hydraulic clutch/brake (6)...
... Solenoid valve, (8) ... Clutch (9) ... Brake, C down mark ...
heater device. 1st (i21 30th 40th 2nd

Claims (1)

[Claims] A method of operating a machine tool characterized by operating the solenoid valve itself for controlling a hydraulic clutch or hydraulic brake while keeping it warm.