JPH0788000B2 - Bottom dead center adjustment device for press slides - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a bottom dead center adjusting device for a press slide, and more particularly, it provides at least three sensors having different detection points with respect to the descending position of the press slide, and adjusts the slide corresponding to the output patterns of the at least three sensors. The present invention relates to a bottom dead center adjusting device for a press slide that operates the device.

2. Description of the Related Art In a press machine, each part expands due to heat generated during operation. Generally, the expansion that occurs between the crankshaft and the slide is larger than the expansion that occurs in the frame. Tend to approach each other relatively. Since such a change in the bottom dead center position causes a large deterioration of the precision of the molded product, generally, when the bottom dead center position of the slide fluctuates, the slide adjusting mechanism is operated. By doing so, the bottom dead center position is corrected. Regarding the detection of the bottom dead center position of the slide, there was a method of applying a scale periodically to perform visual measurement, but in recent years, automation of slide adjustment has become popular. Various modifications can be considered as specific modes of automated slide adjustment, but basically, the linear relative position of a slide is relative to a bolster is read in an analog manner by a linear scale such as a potentiometer, and AD change or digital calculation is performed. The slide adjustment mechanism is operated based on the processing and the processing such as comparison with the reference bottom dead center position.

[Problems to be Solved by the Invention]

However, in the case of the above-mentioned conventional method, since it involves AD conversion and software processing, it takes a long time to determine whether the slide is moving up or down, and also due to the responsiveness of the slide adjusting mechanism itself. Therefore, there is a problem that a high-SPM press must be averaged over several strokes, and it also takes time to measure the accuracy of the bottom dead center position detection mechanism itself. It was

[Means for solving problems]

The present invention has been made in view of such problems,
A first object of the present invention is to provide a bottom dead center adjusting device for a press slide, which can shorten the time required to determine whether the slide is moving up or down. The present invention also provides a bottom dead center adjusting device for a press slide in which the responsiveness of the slide adjusting mechanism itself is also improved.
The purpose of. A third object of the present invention is to provide a bottom dead center adjusting device for a press slide, which can easily diagnose the bottom dead center position detecting mechanism itself. The above-mentioned object of the present invention is achieved by the means described below. That is, the bottom dead center adjusting device of the press slide of the present invention is based on: a press device provided with a slide adjusting mechanism for adjusting the bottom dead center position of the press slide: The present invention is characterized in that at least three bottom dead center sensors having different points are provided, and the slide adjusting mechanism is operated in accordance with an output pattern of the at least three bottom dead center sensors. More preferably, the bottom dead center adjusting device of the press slide of the present invention is based on the above: a first bottom dead center sensor that operates even when the bottom dead center of the slide is relatively high,
A second bottom dead center sensor that operates when the bottom dead center of the slide is relatively middle, and a third bottom dead center sensor that operates when the bottom dead center of the slide is relatively low. Each is equipped with: When the first bottom dead center sensor does not operate, the slide adjusting mechanism is operated in the descending direction, and when the third bottom dead center sensor is also operating, the slide adjusting mechanism is operated in the ascending direction. Has been done. Further, preferably, the bottom dead center adjusting device of the press slide of the present invention is based on the above: the slide adjusting mechanism is a worm wheel screwed with a connecting rod suspended on a crank, and a worm gear for rotating the worm wheel. And a cylinder mechanism for moving the worm gear in the axial direction thereof. The worm wheel is turned by the movement of the worm gear in the axial direction. Further, preferably, the bottom dead center adjusting device of the press slide of the present invention is based on the above: The at least three bottom dead center sensors are arranged in a single casing.

[Action]

That is, according to the present invention, if the actual bottom dead center position is higher than the supposed bottom dead center position, the bottom dead center sensor among the plurality of bottom dead center sensors that should be operated does not operate, On the other hand, if the actual bottom dead center position is lower than the proper bottom dead center position, even the bottom dead center sensors that should not be operated among the plurality of bottom dead center sensors will operate. The normal / abnormal position of the bottom dead center position can be recognized by the ON / OFF operation patterns of the plurality of bottom dead center sensors, including their directions. Further, the correction operation of the bottom dead center position based on the above recognition is also an operation of moving the worm gear in the axial direction by the operation of the cylinder mechanism, so the correction is performed several times faster than the turning operation from the motor through the gear train. It Further, a single casing accommodating these plural sensors is arranged at an appropriate position near the mold.

【Example】

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a structural explanatory view of a pressing device to which the present invention is applied, and FIG. 2 is a sectional view taken along the line AA ′ of the slide portion in FIG. The crank 1 is pivotally supported on the frame 2, and the crank 1
The flywheel 3 provided at the tip of one of the two is connected to a motor 5 via a belt 4. A connecting rod 6 is suspended from the crank 1, and a connecting screw 7 is screwed onto the lower end surface of the connecting rod 6. A ball 9 is fixed to the tip of a rod 8 formed integrally with the connecting screw 7, and a slide 11 having an upper die 10 fixed to the lower surface is suspended on the ball 9 as described in detail below. That is, the worm wheel 12 is rotatably housed in the circular hole formed in the center of the slide 11.
The upward escape of the worm wheel 12 with respect to 11 is defined by a ring-shaped worm wheel retainer 13. The ball 9 is connected to the inner peripheral surface of the worm wheel 12 by a connecting pin 14 so that the connecting screw 7 rotates as the worm wheel 12 turns.
The backlash of the ball 9 with respect to the worm wheel 12 is suppressed by the ball retainer 15 and the ball cup 16. A worm gear 17 that meshes with the worm wheel 12 is housed in the slide 11 orthogonally to the ascending / descending direction of the slide 11, and the worm shafts provided at both ends of the worm gear 17 are provided.
18 is supported on the slide 11 by shaft housings 19 and 20. A motor 24 is connected to a tip portion of the worm shaft 18 penetrating the shaft housing 19 via a sprocket 12-chain 22-sprocket 23, and the rotation of the motor 24 is transmitted through the transmission train so that the worm gear 17 is Rotate. On the other hand, a feature of the present embodiment is that a flange 25 formed at the tip portion of the worm shaft 18 penetrating the shaft housing 20 is supported by a piston 28 via thrust bearings 26 and 27. The piston 28 is a cylinder. Slide inside 29. That is, in the worm wheel 12, as in a general worm mechanism, the rotation of the motor 24 causes the sprocket 23-chain 22-
The bottom dead center position is adjusted by turning by transmission through the sprocket 21, the worm shaft 18, and the worm gear 17, but in addition to the above, the piston 28 moves forward and backward in the cylinder 29. The worm gear 17 also rotates in the axial direction to rotate and adjust the bottom dead center position. Therefore, in this embodiment, the bottom dead center position can be adjusted even with an extremely short transmission time. In addition, 30 is a servo valve,
31 is a metering pump, which is the port 29a ・ 2 of the cylinder 29.
It is for supplying oil to 9b. Of course, the range of movement of the worm gear 17 in the axial direction is not limited, and in this embodiment, therefore, the movement of the worm gear 17 in the axial direction is detected by the limit switch and regulated. A detection rod 32 is provided at the other end of the piston 28, and limit switches 33, 34, 35 are provided near the detection rod 32. First, the limit switch 33 is made by the dog 32a formed on the detection rod 32 when the axial movement of the worm gear 17 is within the allowable range. Further, the limit switches 34 and 35 are made by the dog 32b formed on the detection rod 32 when the axial movement of the worm gear 17 exceeds the allowable range. Next, 40 is a sensor unit that is a feature of this embodiment, and is fixed on the lower mold 37 fixed on the bolster 36.
Details of the structural example are shown in FIG. In the sensor unit 40, the bottom of a cylindrical casing 41 having a sufficient press strength is cut off by an insulating backing plate 42, and a conductive contact pin 43 is provided upright at the center of the upper surface of the backing plate 42. Concentric contact rings 44 and 45 are arranged around the pins. Insulating rings 46, 47, and 48 are provided between the contact pin 43, the contact rings 44 and 45, and the casing 41 to insulate each other. Detection electrodes 49, 50, and 51 are embedded in the backing plate 42 on the lower end surfaces of the contact pin 43 and the contact rings 44 and 45, respectively. Leads for connecting the detection electrodes 49, 50, 51 and the control circuit are omitted in the drawing. An insulating block 52 with a circular cross section is held in these upper spaces so that it can move up and down.
Conductive push pins 53, 54, and 55 are arranged above the above to penetrate the insulating block 52. Also, push pin 53
A pressure plate 56 is placed on the upper surface of 54 and 55, and a power line 57 connected to the pressure plate 56
Is connected to each push pin 53, 54, 55. An insulating ring 58 is arranged around the backing plate 42. On the other hand, a lock nut 59 is fixed to the lower end surface of the upper mold 10, and a pusher rod 60 is screwed onto the lock nut 59. A feature of this embodiment is that the contact pin 43 and the contact rings 44 and 45 are sequentially stepped, and the lock nut 59 and the pusher rod are lowered as the slide 11 descends during press operation. When 60 pushes down pressure plate 56 and insulating block 52, push pin
55 and the detection electrode 51, between the push pin 54 and the detection electrode 50, and between the push pin 55 and the detection electrode 49 are contact rings 45 and 44, respectively.
And the contact pins 43 are sequentially conducted. When the slide 11 reaches the correct bottom dead center position, the push pin 55 and the detection electrode 51 and the push pin 54 and the detection electrode 50 are electrically connected, and the push pin 53 and the detection electrode 49 are not electrically connected. , Adjust the screwing amount of the pusher rod 60 to the lock nut 59. Although not shown in FIG. 3, a spring or the like is provided below the insulating block 52 for lifting the full-edge block 52 under no load. Next, FIG. 4 is a digital circuit diagram showing an example of a control circuit applied to the present invention. In the figure, 33, 34, and 35 are the limit switches 33, 34, and 35 described above, and 49, 50, and 51 are the detection electrodes 49, 50, and 51 described above. Further, 61, 62, and 63 are detection electrodes 51, respectively.
An AND gate for inputting the signal applied from 50/49. The AND gates 61, 62, 63 are linked to the crank shaft of the press machine, and the signal of the rotary cam switch 64 that makes near the bottom dead center is turned on. At that time, the outputs of the detection electrodes 51, 50, 59 are transmitted to the set inputs of the flip-flops 65, 66, 67, respectively. The output of the rotary cam switch 64 is applied to the down-edge trigger one-shot circuit 68, and the pulse generated by the one-shot circuit 68 is also applied to the down-edge trigger one-shot circuit circuit 69. First, the one-shot circuit 68 is for creating a timing signal for operating the AND gate 70 for outputting the slide up signal and the AND gate 71 for outputting the slide down signal.
Only at the timing of the level, the AND gate 70 can output the slide up signal and the AND gate 71 can output the slide down signal. Further, as described above, the flip-flop 65 is connected to the detection electrode 51,
The flip-flop 66 includes the detection electrode 50 and the flip-flop 67.
Correspond to the detection electrodes 49, respectively, and in the present embodiment, when an accurate bottom dead center position is obtained, only the detection electrodes 51 and 50 make up near the bottom dead center and the flip-flops 65 and 66 are made.
Only set. The Q outputs of the flip-flops 65 and 66 and the output of the flip-flop 67 are connected to the NAND gate 72. Therefore, in the NAND gate 72, only the flip-flops 65 and 66 are set, and the flip-flop 67 is not set. In the state (that is, the state where the accurate bottom dead center position is obtained), the AND gate 70
・ Prohibits 71 from outputting slide up signal and slide down signal respectively. The output of the flip-flop 66 is connected to the AND gate 71, and when the detection electrode 50 is not conductive and the flip-flop 66 remains in the reset state, the AND gate 71 outputs the slide down signal at the timing of the pulse generated by the one-shot circuit 68. Is output. Further, the Q output of the flip-flop 67 is connected to the AND gate 70, and even the detection electrode 49 becomes conductive, and when the flip-flop 67 is set, the AND gate 70 slides at the timing of the pulse generated by the one-shot circuit 68. Output a rising signal. Next, the one-shot circuit 69 is a flip-flop 65/66/67.
The flip-flops 65, 66 and 67 are reset by the pulse generated by the one-shot circuit 69 at the timing when the pulse time of the one-shot circuit 68 ends. Next, 73 is a NOR gate that generates a low-active press stop signal when the axial movement of the worm gear 17 exceeds the allowable limit and either of the limit switches 34 and 35 makes, and 74 is the worm gear 17 An AND gate that allows the AND gates 70 and 71 to operate when the axial movement does not exceed the allowable limit and both limit switches 34 and 35 are flaked and the limit switch 33 is making. The output of the AND gate 74 is connected to the AND gates 70 and 71. Next, the operation of this embodiment will be described with reference to the above matters and the time chart of FIG. In the time chart of FIG. 5, the area A shows the case where the actual bottom dead center position coincides with the original bottom dead center position, and the area B shows the actual bottom dead center position where the actual bottom dead center position coincides. When it is above, the area C shows the case where the actual bottom dead center position is below the original bottom dead center position. First, prior to the work, when the bottom dead center position of the slide 11 is at the correct position, the push pins 54 and 55 are respectively contact rings.
The amount of screwing of the pusher rod 60 with respect to the lock nut 59 is adjusted so that the push pin 53 does not come into contact with the contact pin 43 while coming into contact with 44 and 45. Further, the limit switch 33 is made by the dog 32a, and the limit switches 34, 35 are controlled by the dog 32b so that the oil supplied from the servo valve 30 to the cylinder 29 is controlled so that the detection rod 32 is located at a position where it is not made. Now, when the operation of the press machine is started in this state, the rotation of the motor 5 is transmitted to the crank 1 via the belt 4-flywheel 3 and converted into vertical motion by the connecting rod 6, so that the slide 11 moves up and down. To do. Then, when the slide 11 passes near the bottom dead center, the rotary cam switch 64 linked to the rotation of the crank 1 makes. Further, as the slide 11 descends, the pusher rod 60 screwed into the lock nut 59 pushes down the pressure plate 56 and also pushes down the insulating block 52. If the actual bottom dead center position of the slide 11 at this time coincides with the original bottom dead center position, the tips of the push pins 54 and 55 contact the contact rings 44 and 45, respectively, but the push pin 53 contacts. Since it does not contact the pin 43, the detection electrodes 51 and 50 are electrically connected to the power supply line 57, and as shown in the area A of FIG.
Only 51 and 50 turn on. And, as mentioned above, at this point the rotary cam switch
Since 64 is making, the flip-flops 65 and 66 are set through the AND gates 61 and 62, and the flip-flop 67 maintains the reset state. Therefore, Nand Gate
Since the output of 72 becomes L level, rotary cam switch
Even if the one-shot circuit 68 generates a pulse at the timing when 64 breaks, the AND gates 70 and 71 maintain the L level, so that the servo valve 30 shown in FIG. 2 is also locked and the slide 11 is not moved up and down. . Further, when the actual bottom dead center position of the slide 11 is above the original bottom dead center position, the tip of the push pin 54 does not contact the contact ring 44. (Note that the tip of the push pin 55 may or may not be in contact with the contact ring 45, but at least the tip of the push pin 54 does not contact the contact ring 44.
Region B in the drawing shows a case where the tip of the push pin 55 is in contact with the contact ring 45, but the tip of the push pin 54 is not in contact with the contact ring 44. Therefore, as shown in the area B of FIG. 5, only the detection electrode 51 is turned on, only the flip-flop 65 is set, and the flip-flop 66.
67 remains reset. Therefore, in this case, the output of the NAND gate 72 does not become L level. Now, when the rotary cam switch 64 breaks after passing through the bottom dead center, the one-shot circuit 68 generates a pulse. In this case, the flip-flop 66 is reset as described above and the main force is at the H level. The AND gate 71 generates the slide down signal for the pulse time generated by the one-shot circuit 68. Therefore, the servo valve 30 shown in FIG. 2 supplies oil from the fixed amount discharge pump 31 to the port 29b of the cylinder 29. This oil supply causes the worm gear 17 to move upward in FIG. 2, so that the worm wheel 32 rotates clockwise in FIG. 2 and rotates the ball 9 via the connecting pin 14, so that the connecting screw 7 also moves upward. When viewed from the inside, it rotates clockwise and slide 11 descends. On the other hand, when the actual bottom dead center position of the slide 11 is below the original bottom dead center position, even the tip of the push pin 53 contacts the contact pin 43. Therefore, as shown in the area C of FIG. 5, all the detection electrodes 51, 50, 49 are turned on and all the flip-flops 65, 66, 67 are set. Therefore, also in this case, the output of the NAND gate 72 does not become L level. Now, when the rotary cam switch 64 breaks after passing through the bottom dead center, the one-shot circuit 68 generates a pulse. In this case, as described above. Because the flip-flop 67 is also set and the Q main power is at the H level, the one-shot circuit
The AND gate 70 generates a slide rising signal for the pulse time generated by 68. Therefore, the servo valve 30 shown in FIG. 2 supplies oil from the fixed amount discharge pump 31 to the port 29a of the cylinder 29. This oil supply causes the worm gear 17 to move downward in FIG. 2, so that the worm wheel 32 rotates counterclockwise in FIG. 2 and rotates the ball 9 via the connecting pin 14, so that the connecting screw 7 also moves. When viewed from above, the slide 11 rotates counterclockwise, and the slide 11 rises. Now, when the bottom dead center position is corrected by moving the worm gear 17 in the axial direction only in one direction, the dog 32a formed on the detection rod 32 eventually comes off the limit switch 33, and the limit switch 33 moves. At the same time as the break, the dog 32b formed on the detection rod 32 makes either of the limit switches 34 and 35. When either of the limit switches 34 and 35 is made, the output of the NOR gate 73 becomes L level, a low active stop signal is generated, and the press machine stops at a fixed position. Further, since the output of the AND gate 74 is also at the L level, the AND gates 70 and 71 are closed and the slide up signal and the slide down signal are not output regardless of the states of the flip-flops 65 to 67. Then, after stopping at a fixed position, the servo valve 30 is operated to return the piston 28 to the neutral position, and the worm gear 17 is offset only by canceling the rotation of the worm wheel 12 accompanying the axial movement of the worm gear 17 at this time. It is rotated by the motor 24 to adjust the bottom dead center position. Next, FIG. 6 shows a modification of the present invention. That is, in the embodiment described above, the concentric contact rings 44 and 45 are arranged around the contact pin 43, but in the example shown in FIG.
Push pin 54a / 54b / 54c / 54d for each arcuate contact 44a / 44b / 44c / 44d / 45a / 45b / 45c / 45d divided into a / 44b / 44c / 44d / 45a / 45b / 45c / 45d.・ 55a ・ 55b ・ 55c
・ 55d contacts and each arc-shaped contact 44a ・ 44b ・ 4
Detection electrodes (not shown) are provided for each of 4c, 44d, 45a, 45b, 45c, and 45d. In this case, when the slide 11 is inclined due to an eccentric load or the like, for example, the push pin 54a is in contact with the arcuate contact 44a while the push pin 54c is in contact with the arcuate contact 44c which is opposed to the pushpin 54a. Since such a state as not occurring occurs, the tilt error can be detected. In any of the above examples, a compressive load is applied to the outer push pin than to the inner push pin, but there is no practical problem as long as it is within the elastic recovery limit. Also, in the above, an example is shown in which the detection operation is performed by electrical conduction due to contact between the push pin and the contact ring (or contact pin or arc-shaped contact), but as long as a step is provided on the operating surface as described above, For example, it can be replaced with a proximity sensor or the like. Further, in the above, the example in which the operation timing is delayed for the inner sensor is shown, but the operation timing may be delayed for the outer sensor. Furthermore, in the above, three sensors are used to detect whether the bottom dead center is at the original position, above the original position, or below the original position. However, it is also possible to provide more sensors and control even the correction amount of the bottom dead center position according to the output pattern.

【effect】

As described above, according to the present invention, since the bottom dead center position is recognized by the ON / OFF pattern of the sensor output, AD conversion and software processing are not required when recognizing the bottom dead center position. The recognition speed of the dead center position is significantly improved. Further, according to the present invention, unlike the conventional mechanism in which the bottom dead center position adjusting mechanism transmits the rotation of the motor to the worm wheel via the gear train, the worm gear is directly moved in the axial direction by the cylinder. The response of the bottom dead center position adjusting mechanism is also improved. Therefore, according to the present invention, the adaptability for high-speed pressing is significantly improved. Further, since it suffices that it is confirmed that the sensor of the present invention can simply perform the on / off operation without fail, the detection mechanism itself can be diagnosed only by forcibly giving the condition for turning on or off each sensor. Easy to do. For example, by forcibly lowering the slide to a position where all sensors would be on during operation, or
When using proximity sensors, it is possible to diagnose that there is no failure if all the sensors are turned on by forcibly reducing the threshold level to a level at which all the sensors are turned on.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a pressing apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA ′ in FIG. 1, FIG. 3 is a perspective view in which a sensor unit is partially broken, and FIG. FIG. 6 is a digital circuit diagram showing a control circuit, FIG. 5 is a time chart of the present embodiment, and FIG. 6 is a schematic diagram showing a modification of the present invention. 7 …… Connecting screw 9 …… Ball, 11 …… Slide 12 …… Warm wheel, 17 …… Warm gear 18 …… Warm shaft, 28 …… Piston 29 …… Cylinder, 30 …… Servo valve 31 …… Measures pump , 40 …… Sensor unit 43 …… Contact pin, 44 ・ 45 …… Contact ring 44a ・ 44b ・ 44c ・ 44d ・ 45a ・ 45b ・ 45c ・ 45d …… Arc contact 49 ・ 50 ・ 51 …… Detection electrode 53 ・54/55 / 54a / 54b / 54c / 54d / 55a / 55b / 55c / 55d
...... Push pin 56 …… Pressure plate 59 …… Lock nut, 60 …… Pusher rod

Claims (1)

[Claims] 1. A press device comprising a slide adjusting mechanism for adjusting the bottom dead center position of a press slide, wherein at least three bottom dead center sensors having different detection points are provided at the lower position of the press slide, and the at least three bottom dead center sensors are provided. A first bottom dead center sensor that operates even when the bottom dead center of the slide is relatively high, and the bottom dead center sensor that operates in accordance with the output pattern of the bottom dead center sensor. A second bottom dead center sensor that operates when the point position is relatively middle, and a third bottom dead center sensor that operates when the bottom dead center of the slide is relatively low are provided. When the bottom dead center sensor does not operate, the slide adjusting mechanism is operated in the descending direction, and when the third bottom dead center sensor is also operating, the slide adjusting mechanism is operated in the ascending direction. The ride adjusting mechanism includes a worm gear for turning a worm wheel screwed with a connecting rod suspended on a crank, and a cylinder mechanism for moving the worm gear in its axial direction. A bottom dead center adjusting device for a press slide, wherein the worm wheel is rotated.