JPS6021840B2 - Press machine slide bottom dead center position correction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bottom dead center position correcting device for a slide of a press machine.

Press machines generally have a problem in that the bottom dead center position of the slide changes when operating at high speeds or for long periods of time.

The reason for this is that the higher the speed of the press, the greater the inertia applied to the slide, so even though the weight of the slide is balanced using an air balancer, etc., the slide may die due to gaps around the crank. The bottom dead center position of the slide will drop, and if the press is operated for a long time, the heat generated by the press will cause the connections and other connections to tighten on the hot side, causing the bottom dead center position of the slide to drop. , and if the operation was continued, the frame (especially the column and tie rod) would expand thermally and the bottom dead center of the slide would drop.

Therefore, in order to correct such changes in the bottom dead center position, conventional measures have been taken such as installing a stopper to limit the bottom dead center position or making fine adjustments to the press machine one by one. was.

However, in the former case, there are problems in that the capacity of the press machine is lost and in precision machining, it is difficult to adjust the stopper, and in the latter case, it is extremely labor-intensive and reduces the operating rate of the press machine. There was a problem that the performance decreased.

Therefore, in view of the above, the present invention aims to provide a bottom dead center position correction device for a press machine that can automatically correct the bottom dead center position without causing any loss in press machine capacity. It is something.

In order to achieve the above object, the present invention is characterized in that the bottom dead center position of the slide is adjusted by adjusting the oil temperature of the lubrication system.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, to briefly explain the press machine 1, the bed 2
A polster 3 is provided on the top of the holder.

Four tie rods 4 are further installed on the bed 2. A connection screw 6 is swingably provided at the top of the slide 5, and this connection screw 6 is screwed onto a connection 8. Further, the connection 8 is provided so as to be swingable relative to the crank pin 8a. On the other hand, a flywheel 10 is provided on the crankshaft 7, which is rotatably supported by bearings 7a, 7a. are connected. Note that a lubrication system consisting mainly of the connecting portion between the connection 8 and the crank pin 8a, the connecting portion between the connection screw 6 and the slide 5, and the bearings 7a, 7a is provided. Moreover, a variable speed motor is used for the motor 11. On the other hand, two sensors 14, 14 for detecting the bottom dead center position of the slide 5 are provided on both ends of the bolster 3 via brackets 14a, 14a, respectively.

In this example, the sensors 14, 14 are magnetic sensors having internal coils (not shown). However, other methods such as capacitive sensors and ultrasonic sensors may also be used. 15 is the lower mold attached to the bolster 3,
16 is an upper die attached to the slide 5.

Next, the oil temperature control circuit 17 will be explained.

In this example, the oil temperature control circuit 17 is the oil temperature adjusting section 1 shown in FIG.
7A and an oil temperature setting section 17B shown in FIG. Therefore, first, the oil temperature adjustment section 17A will be specifically explained. As shown in FIG. 2, the oil temperature adjustment section 17A mainly includes a cooling section 30 and a heating section 31, and the cooling section 30 further includes a condenser 32, a condenser fan 33, and a cooling tank 3.
4, consisting of a cooling coil 35, a combustor 36, a dryer filter 37, and a cavity tube 38,
The heating section 31 further includes a heater 39, a heating tank 40, and a thermistor SAI.

The cooling tank 34 is supplied with oil from the reservoir tank 43 by the circulation pump 42, and the oil supplied to the cooling tank 34 is supplied to the cooling tank 34 and the connecting pipe 4.
1. It is designed to be recycled to a reservoir tank 43 via a heating tank 40 and a discharge pipe 44.

On the other hand, the oil in the reservoir tank 43 is supplied to the press machine 1 by an oil pump 45, and the oil supplied to this press machine 1 circulates through each connecting part and sliding part, and then is transferred to the press machine 1. It is collected at the port 46 and refluxed to the reservoir tank 43. In addition, 47 is a bypass pipe for circulating surplus oil, 48 is a valve for adjusting the flow rate of lubricating oil supplied to the press machine 1, 49 is a valve for adjusting the flow rate of surplus oil, RE is a shield valve, S
A2 is a thermistor for detecting oil overflow in the reservoir tank 43. Next, the oil temperature setting section 17B will be explained.

As shown in FIG. 3, the oil temperature setting section 17B is composed of an oil temperature setting circuit 17Ba and a motor control circuit 17Bb. The motor control circuit 17Bb mainly includes a motor M5 for driving the press machine 1, a motor M2 for driving the circulation pump 42, a motor M4 for driving the oil feed pump 45, a motor M2 for the compressor 36, and a motor for the condenser fan 33. - It is configured as a sequence circuit for supplying power to the motor M3. Motor M1, M
4 and M5 are activated by turning on the electromagnetic switch 24 (when the electromagnetic switch 24 is turned on, relay MS1
, MS3, and MS4 are activated, so their respective normally open contacts M
S1a, MS3a, MS4a are turned on and motor M1,
Motors M2 and M3 are activated by turning on relay MS5 of temperature controller circuit 23. (When relay MS5 is activated, normally open contact MS5a is turned on and relay MS2 is activated, so normally open contact MS2a is turned on and motor M
Note that OLI to OL4 indicate overload relays, FI to F4 indicate fuses, and M circle indicates a motor protector that cuts off current in the event of overcurrent or excessive temperature rise. Next, the oil temperature setting circuit 17 will be explained.

As shown in FIG. 3, the oil temperature setting path 17 is mainly composed of a detection circuit 18, an A-○ converter 19, a CPU 20, a selection circuit 21, and a speed setting resistor circuit 22.
The detection circuit 18 includes an oscillation circuit, a voltage detection circuit, and an average value circuit (not shown).

The high frequency output from the oscillation circuit is applied to coils (not shown) of the sensors 14, 14, and the voltage values generated between both terminals of the coils are detected by a voltage detection circuit. In other words, slide 5 is the sensor 14, 14
When approaching, the sensor 14
, 14, the magnetic permeability of the coils changes. Then, the voltage value generated between both terminals of the coil to which the high frequency voltage is applied changes, and this is detected by the voltage detection circuit. However, the value detected by this voltage detection circuit is between the slide 5 and the sensor 14 at the bottom dead center position.
This is a value related to the distance h from Each voltage value detected by this voltage detection circuit is input to an average value circuit, the average value of which is taken, and then input to the A-◯ converter 19. The A-D converter 19 is the detection circuit 1
8 is for converting the signal related to the distance h between the sensor 4 and the slide 5 located directly at the bottom dead center from analog to digital, and this digital converted signal is input to the CPU 20. There is.

The CPU 20 inputs a signal related to the distance h from the A-D converter 18, and calculates the difference from a reference value (reference distance h) set in advance in the CPU 20 (if this difference is positive, This difference may be a preset limit value (this limit value is set as a binary value of plus and minus) N times (the value of N may be set appropriately in advance). ) A predetermined control signal (the correspondence between the overage and the control signal is set in advance in the CPU) is output to the selection circuit 21 according to the degree of the overage when the overage occurs continuously. It is built like this. The selection circuit 21
inputting a control signal from 20 and corresponding to this signal;
Oil temperature setting resistance VRI to VR6 in the temperature setting resistance circuit
and relay contact RL for selecting and starting VR1a to VR6a
It is a circuit for operating PL7a and PL7a, and is formed as a kind of decoder.

The temperature setting resistance circuits 22a and 22b include a plurality of temperature setting resistances (in this example, a half-time constant volume is used).
VRI~VR6, VR1a~VR6a, relay contact RL
1a to RL6a, PL1a to PL6a and main variable resistor R
1, R1a is the main component.

These relay contacts RL1a to RL6a and PL1a to PL
6a are relays RLI to RL6 and PLI to PL, not shown, which are operated by a control signal from the selection circuit 21.
6 normally open contact, and when this contact is turned on, predetermined temperature setting resistors VRI~VR6 and VR1a~
VR6a is now selected. Next, the temperature controller circuit 23 will be explained.

This temperature controller circuit 23 consists of a heating part control circuit of a phase control type (not shown) mainly consisting of a triator, a trigger UJT, and a thermistor SAI, and a thermistor S
A2 and a normal cooling unit control circuit (not shown) mainly consisting of a comparator. This temperature controller circuit 23 is similar to the temperature control circuit for well-known heaters and coolers, and the temperature setting part that is normally controlled by changing the volume is replaced with a temperature setting part that is set to a predetermined value in advance. Resistance VRI~VR6, VR1a
~VR6a to relay contact Rala~RL6a, PL1a
~ PL7a to be selected and replaced. That is, by selecting the resistor VR6, a temperature of 60 degrees, for example, is set, and the heating control circuit (not shown) in the temperature controller circuit 23 controls the oil temperature adjusting section 17A to maintain the temperature of the lubricating oil at 60 degrees.
In other words, it controls the By doing so, when the bottom dead center position of the slide 5 changes, the temperature of the lubricating oil can be set to a predetermined temperature corresponding to the amount of change. (The amount by which the bottom dead center position has changed and the temperature set value corresponding to the degree of the change are each set in advance in the CPU 20.) This controller 23 controls the heater 39 and controls the second temperature by the IJ Ray MS5. The operation instruction for controlling the cooling unit 30 shown in the figure is relay contact RL7.
a and PL7a.
(The relays RL7 and PL7 (not shown) having the relay contacts RL7a and PL7a are operated by a signal from the selection circuit 21. That is, a predetermined threshold value is set in the CPU 20, This corresponds to, for example, the interval h between the slide 5 and the sensor 14. When the signal from the A-D converter 19 is above the threshold value (for example, h>5 skins), the CPU 20 uses the temperature setting resistor. Relay contact RL7a is also activated along with a predetermined relay contact in circuit 22b, and when the threshold value is below (for example, h<5 legs)
At this time, the relay contact PL7a is activated together with a predetermined relay contact in the temperature setting resistance circuit 22a. In other words, the relay contacts RL7a and PL7a serve as a kind of activation switch for the cooling section control circuit and the heating section control circuit within the temperature controller circuit. ) In the above configuration, when the motor 11 is rotated, the crankshaft 7 is rotated via the pulley 12, belt 13, and flywheel 10.

Then, the slide 5 is moved up and down in the drawing by the connection screw 6 connected to the crank pin 8a. That is, the press is performed by the vertical movement of the slide 5. On the other hand, the bottom dead center of the slide 5 is the sensor 14,
14 and obtained sensor 1
A signal regarding the distance h between 4 and the slide 5 is sent to the detection circuit 18.
, and is input to the CPU 20 via an A-D converter.

As mentioned above, the signal input to the CPU 20 is
Calculate the difference from the reference value (reference distance h) set in advance in U20, and calculate the difference with the preset limit value N times (the value of N is set appropriately in advance). ) A predetermined control signal is outputted to the selection circuit 21 in accordance with the degree of the amount of excess when the amount exceeds continuously.

Then, the selection circuit 21 operates a predetermined relay (not shown) corresponding to the control signal (this correspondence relationship is set in advance). Now, for example, assuming that the bottom dead center position has risen above the reference value, the CPU 20 selects the selection circuit 21 in order to set the lubricating oil to an oil temperature corresponding to this displacement amount (in this case, the oil temperature is increased). Send a predetermined signal to activate the relay.

If these relays are, for example, PL3 and PL7, their normally open contacts PL3a and PL7a are turned on, the temperature setting resistor VR3a is selected, and a heating section control circuit (not shown) is activated. (At this time, the operation of relay contacts that were previously turned on is naturally canceled.) Therefore, the resistance values set by the temperature setting resistor VR3a and the main variable resistor R1a are set at the terminals A and B of the temperature controller circuit 23. As a result, the temperature of a heating control circuit (not shown) in the temperature controller circuit 23 is set. In other words, the amount of heat generated by the heater 39 is controlled so that the temperature corresponds to the resistance value set between the terminals A and B. Therefore, in this case, since the oil temperature rises, the bottom dead center of the press 1, which had been rising due to heat retention, falls to the reference value. In addition, when the bottom dead center position hawk descends, the cooling unit 30 is operated this time by the same control as described above, and the bottom dead center position is corrected. As described above, in this embodiment, the sensor 14 detects the variation in the bottom dead center position of the slide 5, and if this variation, that is, the error in the bottom dead center position exceeds a predetermined value N times in a row, the CPU 20 detects this and activates a predetermined relay to change the set value of the oil temperature to a temperature corresponding to the amount of displacement of the slide 5.

That is, when the bottom dead center position falls, the set temperature of the lubricating oil is lowered by a predetermined temperature according to the degree of the fall, thereby contracting the connecting parts, etc., and raising the bottom dead center position. When the temperature rises, the set temperature of the lubricating oil is increased by a predetermined temperature according to the degree of rise, thereby expanding the connecting portion and the like, thereby lowering the bottom dead center position. By doing this, the bottom dead center position of the slide 5 can always be kept within a predetermined range. In this embodiment, the number of temperature setting resistors in each of the temperature setting resistor circuits 22a and 22b is six, but this number may be increased or decreased as necessary.

That is, in the present invention, in a press machine of a type that has a lubrication system using lubricating oil at the connecting portion between the slide and the crankshaft, a sensor for detecting the bottom dead center position of the slide, and a sensor for increasing the temperature of the lubricating oil are provided. a heating section, a cooling section for lowering the temperature of the lubricating oil, and a signal regarding the bottom dead center position of the slide from the sensor to control the cooling section and the heating section to adjust the bottom dead center position of the slide. By configuring the bottom dead center position correction device of the press slide from the oil temperature setting circuit that controls the lubricating oil temperature to keep it constant, the press It has an excellent feature of being able to provide a press machine that can always obtain a stable bottom dead center position regardless of the operating state of the machine.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is an explanatory diagram showing the overall configuration of the press machine, Fig. 2 is an explanatory diagram mainly showing the oil temperature adjustment section, and Fig. 3 is an explanatory diagram showing the oil temperature setting section. FIG. 1...Press machine, 5...Slide, 14...Sensor, 1
7...Oil temperature control circuit. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. In a press machine of a type that has a lubrication system using lubricating oil at the connection part between the slide and the crankshaft, a sensor for detecting the bottom dead center position of the slide, a heating part for raising the temperature of the lubricating oil, , a cooling section for lowering the temperature of the lubricating oil, and a signal from the sensor regarding the bottom dead center position of the slide to control the cooling section and the heating section to keep the bottom dead center position of the slide constant. A bottom dead center position correction device for a slide of a press machine, comprising an oil temperature setting circuit for controlling the temperature of lubricating oil so as to maintain the temperature of the lubricating oil.