JPH10249596A - Variable stroke device for mechanical press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable stroke device without causing the difference between left/right strokes with reliable operation by constructing a stroke adjustment device with double eccentric bushings, maintaining a main pin at a stop position and drive controlling a drive shaft to disengage a pinion and a main gear and changing a rotation phase of a second eccentric bushing with rotating a first eccentric bushing. SOLUTION: An inner peripheral circular part 26B eccentric to an outer peripheral circular part 26A of a first eccentric bushing 26 is fitted into a main pin 24 rotatable. An inner peripheral circular part 27B eccentric to an outer peripheral circular part 27A of a second eccentric bushing 27 is fitted into the outer peripheral circular part 26A of the first eccentric bushing 27, double eccentric bushings are constructed. A slier 30A of a pin 30 erected to a side face of the second eccentric bushing 27 is fitted into a groove 25A in the radial direction of a main gear 25, the second eccentric bushing 27 is integrally rotated with the main pin 24. A large gear 31 is arranged coaxially with the main pin 24, a pinion 32 and the main gear 25 are engaged/disengaged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable stroke device of a mechanical press belonging to a double eccentric bush type, which has a simple structure and a reliable operation. This is advantageous in that there is no difference in stroke between points and that switching of strokes can be automated.

[0002]

2. Description of the Related Art In the prior art, a variable stroke device of a mechanical press is used to improve productivity, reduce noise and vibration,
Improvements have been made in accordance with the life of the mold, high precision workability, and other various requirements. The variable stroke device of such a mechanical press uses a double eccentric bush type in which another eccentric bush is rotated by a fixed rotation angle around one eccentric bush, a pin is used for phase fixing, and the rotation angle is detected. Some are detected by a device and rotated by a motor and a gear train.

[0003] Of these prior arts, the one to be compared with the present invention will be described with reference to Fig. 6 of a conventional example corresponding to Fig. 2 of Japanese Utility Model Publication No. 3-44391. An eccentric drum 3 is fitted to an eccentric portion 2 of the main shaft 1, and a connecting rod 4 is connected to a slide 5 on an outer peripheral surface of the eccentric drum 3,
A drum 6 is provided which rotates integrally with the main shaft 1 and is slidable in the axial direction of the main shaft 1. Claws 7 and 8 are formed to be fitted to one end of the drum 6 and one end of the eccentric drum 3, respectively.
The drum 6 is biased and held by a spring 9 in a direction in which the claw portions 7 and 8 engage with each other, and the claw portions 7 and 8 are moved in a direction in which the claw portions 7 and 8 are separated by pressure oil in the annular chamber 10. A gear 13 is provided on a shaft 12 that communicates with an oil hole 11 formed in one shaft center and is rotatably supported on the drum 6. The gear 13 meshes with a ring gear 14 formed on the outer peripheral surface of the eccentric drum 3, and a large gear 15 provided at the other end of the shaft 12 is provided with a first transmission 16 provided with a first gear 16 that rotates around the main shaft 1. It is connected to a stroke adjusting motor 18 by a mechanism and a clutch 17. Further, by a second transmission mechanism having a second gear 20 that rotates a small gear 19 provided on the shaft 12 around the main shaft 1,
The eccentric part 2 is connected to a detector (not shown) that detects the rotation angle of the eccentric drum 3 with reference to the top dead center.

[0004]

Among the above-mentioned prior arts, those using a pin to fix the rotation phase of the double eccentric bush can automate the mechanism for inserting and removing the pin from the hole. However, it is difficult to make the phase accuracy uniform and high accuracy, and this is a problem particularly when equalizing the left and right strokes with a two-point press. As shown in FIG. 6, a mechanism for rotating the eccentric drum 3 is provided by a main shaft 1.
The structure composed of the drum 6 and the like that rotate integrally with the motor becomes an extremely complicated mechanism.
, The accuracy of the stop position is low. Therefore, there is a drawback that the accuracy of the stroke is apt to vary, and when this is applied to a two-point press, the strokes at the left and right points tend to be different, which causes an adverse effect.

[0005] An object of the present invention is to solve the above-mentioned problems, to use a double eccentric bush type, which has a simple structure, is reliable in operation, requires minimal interlock, and is used for a two-point press. An object of the present invention is to provide a variable stroke device for a mechanical press, which does not cause a phase difference between points, that is, a difference between left and right strokes.

[0006]

According to the present invention, there is provided a variable stroke apparatus for a mechanical press, comprising: a main pin having means for maintaining a rotation stop position; and a main pin fixed concentrically to the main pin. A main gear driven from a drive source, a first eccentric bush in which an inner peripheral circle eccentric to an outer peripheral circle is rotatably fitted to a main pin, and a first eccentric inner peripheral circle eccentric to the outer peripheral circle. A second eccentric bush that is rotatably fitted to the outer circumferential portion of the bush, engages with the main gear, rotates integrally with the main pin, and raises and lowers the slide with the connecting rod rotatably fitted to the outer circumferential portion; Concentrically and rotatably fitted to the main pin and locked to the first eccentric bush, the same diameter as the main gear.
A large gear having the same number of teeth, a drive shaft having a pinion that meshes with the main gear and the large gear, movable in the axial direction, and driven and controlled to two positions where the pinion is disengaged from the main gear;
A detector for directly or indirectly measuring the rotation angle of the first eccentric bush, and driving the drive shaft in the axial direction while maintaining the main pin at the rotation stop position, thereby engaging the pinion with the main gear. Then, the first eccentric bush is rotated to change the rotation phase with the second eccentric bush.

In the above variable stroke device for a mechanical press, the first eccentric bush is locked to the main pin.
Or fix it, engage the second eccentric bush with the large gear,
Means for maintaining the rotation stop position on the large gear is provided.

[0008]

1 to 4 show a first embodiment of a variable stroke device for a mechanical press according to the present invention.

FIG. 1 shows a two-point press 21 shown in FIG.
3 shows the details of the structure of the variable stroke device 22 in FIG.
A main gear 25 is concentrically keyed to a main pin 24 rotatably supported by the frame 23. The outer peripheral circular portion 26A of the first eccentric bush 26 is rotatably fitted to the main pin 24 with the inner peripheral circular portion 26B, and the second eccentric bush 27 is further fitted to the outer peripheral circular portion 26A of the first eccentric bush 26. The outer eccentric bush 2 is formed by rotatably fitting the eccentric inner circumference 27B and the eccentric inner circumference 27B.
The connecting rod 28 is rotatably fitted to the outer circumferential portion 27A of the connector 7 and the other end 28A of the connecting rod 28 is connected to the slide 29. A slider 30A is rotatably provided on a pin 30 erected on the side surface of the second eccentric bush 27, the slider 30A is engaged with a radial groove 25A of the main gear 25, and the second eccentric bush 27 is
4 so as to rotate integrally.

The large gear 31 concentrically and rotatably provided on the main pin 24 has the same diameter and the same number of teeth as the main gear 25, and the side surface is fixed to the side surface of the second eccentric bush 26 with a screw 31A. A drive shaft 33 having a pinion 32 meshing with a main gear 25 and a large gear 31 is connected to a frame 23.
The pinion 32 is disengaged from the main gear 25 by being driven and controlled by a hydraulic device (not shown) in the axial direction for a distance L larger than the width of the main gear 25. The main gear 25 and the large gear 31 are driven to rotate by a drive device to be described later via a pinion 32 and a drive shaft 33 to move the slide 29 up and down.

In FIG. 2 showing the structure of the variable stroke device 22 in the two-point press 21, a main pin 2 is shown.
4 engages the main gear 25 and the large gear 31 with the plurality of pinions 32 of the drive shaft 33, respectively.
2 further meshes with a drive gear 35 of a drive shaft 34,
Flywheel 3 rotated by a main motor (not shown)
6 is transmitted and interrupted by the clutch / brake 37.

The drive shaft 34 is provided with an encoder 38 for detecting a rotation angle. The drive gear 35 has the same diameter and the same number of teeth as the pinion 32. This is to make it easier to calculate the rotational phase of the first eccentric bush 26 and the second eccentric bush 27 described later, but there is no problem even if the number of teeth is different.

A disk 39 is fixed to the drive shaft 33, cylinders 40, 40 for pushing the disk 39 from both sides are provided, and the hydraulic pressure of the ports a, b of the cylinders 40, 40 is switched to drive the drive shaft 33 in the axial direction. The reciprocating drive is controlled by the distance L. A brake 41 is provided at one end of the main pin 24, and is used for adjusting the stroke after stopping the operation of the two-point press 21 with the clutch / brake 37.

FIG. 3 is a side view of FIG.
4, main gear 25, large gear 31, first eccentric bush 2
6 is a conceptual diagram for examining a relative position between a sixth eccentric bush and a second eccentric bush. The eccentricity e of the center O1 of the outer circumferential portion 26A of the first eccentric bush 26 with respect to the center O of the main pin 24
1. Center O2 of outer circumferential portion 27A of second eccentric bush 27
When the eccentric amount e2 is above the top dead center, that is, above, the slide 29 that moves up and down via the connecting rod 28 has the maximum stroke 2e = 2 (e1 + e2). In this case, the amount of eccentricity e1 = e2
And

A method of adjusting the stroke of the two-point press 21 will be described with reference to FIGS. First,
When the press operation is performed with the maximum stroke 2e in FIG. 3, the slide 29 is stopped at the top dead center by the clutch / brake 37. Next, the brake 41 is operated to control the main pin 24. Ports a, b of cylinders 40, 40
And the drive shaft 33 is moved by the distance L to disengage the main gear 25 from the pinion 32.
The clutch / brake 37 is operated, the drive shaft 34 is rotated at a low speed, and the first eccentric bush 26 is rotated through a required angle via the drive gear 35, the pinion 32, and the large gear 31.

As shown in FIG. 4 (a), the first eccentric bush 26 is 71% smaller than the brake 41, the main pin 24, the main gear 25, the pin 30 and the second eccentric bush 27 which is braked via the slider 30A. When rotated by degrees,
The stroke of the slide 29 is 2e × 0.75, FIG.
As shown in (b), when the first eccentric bush 26 rotates 107 degrees, the stroke of the slide 29 becomes 2e × 0.
5, when the first eccentric bush 26 rotates 142.5 degrees as shown in FIG. 4 (c), the stroke of the slide 29 becomes 2e × 0.25, as shown in FIG. When the bush 26 rotates 180 degrees, the stroke of the slide 29 becomes 2e × 0. However, the eccentricity e1 =
e2. The amounts of eccentricity e1 and e2 may be different values, but the stroke is naturally slightly different from that described above. When the drive shaft 33 is restored, the pinion gear 32 is engaged with the main gears 25 and 25 and the large gear 31, and the brake 41 is released, the operation can be performed with the adjusted stroke.

The rotation angle of the first eccentric bush 26 described above is for the case where the number of teeth of the main gear 25 is exactly the same, and the pinion 32 is engaged. When the number of teeth is different, the angle at which the engagement is established is selected. Obviously, the adjusted stroke is also different. When the press operation is performed with the adjusted stroke and the stroke is adjusted again to a different stroke, the press operation is stopped at the position where the rotation angle of the first eccentric bush 26 in the adjusted stroke is indicated by the encoder 38, and the slide 29 is temporarily discharged. After returning to the point, the adjustment operation described above may be performed.

As shown in FIG. 2, it is apparent that one variable stroke device 22 can be used as a one-point press.

A second embodiment of the C frame press 44 shown in FIG. 5 will be described with the same reference numerals given to the same components as described above. As shown in FIG. 5A, the main gear 25 is keyed concentrically with the main pin 24, and the first eccentric bush 26 is fixed to the main pin 24 to form a so-called eccentric portion. An outer circumferential circle 27A of the second eccentric bush 27 is rotatably fitted to an outer circumferential circle 26A of the first eccentric bush 26 so as to be rotatable.
The other end 28A of the connecting rod 28 rotatably fitted to 7A is connected to a slide 29.

A slider 30A rotatably provided on a pin 30 projecting from the side surface of the second eccentric bush 27 is engaged with a radial groove 31B of a large gear 31 provided concentrically and rotatably on the main pin 24. I agree. The pinion 32 meshing with the main gear 25 and the large gear 31 is
The drive shaft 33 is provided in parallel with the drive shaft 33.

A cylinder 40 for moving the drive shaft 33 in the axial direction is provided, the hydraulic pressure of the cylinder 40 is switched to move the pinion 32 by a distance L, and drive control is performed to two positions where the engagement between the pinion 32 and the main gear 25 is disengaged. I do. When the pinion 32 is moved to a position outside the main gear 25, the pinion 3
2 mesh with each other as shown in the view of the arrow A in FIG. 5B to maintain the large gear 31 at the rotation stop position.

The main gear 25 meshes with a drive gear 35 of a drive shaft 34, and the power of a flywheel 36 rotated by a main motor 43 is interrupted by a clutch / brake 37 and transmitted. An encoder 38 for detecting the rotation angle of the main pin 24 is provided.

To adjust the stroke, the slide 29 is first stopped at the top dead center by the clutch / brake 37 and the cylinder 40 is stopped.
To move the drive shaft 33, disengage the pinion 32 from the main gear 25, and use the stopper 42 to
2. After the second eccentric bush 27 is locked via the large gear 31, the pin 30, and the slider 30A, the clutch / brake 37 connects the drive shaft 34, the drive gear 35, and the main gear 25 to the main pin 24. The fixed first eccentric bush 26 is rotated at a low speed to change the rotation phase with the second eccentric bush 27. Others are the same as the above-described first embodiment.

[0024]

As is apparent from the above description, according to the present invention, the position where the main gear or the large gear meshes with the pinion is always accurate, so that the stroke adjustment accuracy is high and the present invention can be applied to a two-point press. Even if there is no difference between the left and right strokes. In addition, the structure is simple, the operation is reliable, and the main gear and the large gear have the same diameter and the same number of teeth. Can be manufactured in Furthermore, just by providing an encoder for angle detection,
Effects such as minimizing the interlock are obtained.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a main part of a variable stroke device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a variable stroke device used in a two-point press.

FIG. 3 is a conceptual side view showing the relative positions of respective parts in FIG. 1;

FIG. 4 is an explanatory diagram of stroke adjustment.

5A is a side sectional view of a main part of a variable stroke device according to a second embodiment of the present invention. FIG.

FIG. 6 is a side sectional view of a main part of a conventional variable stroke device.

[Explanation of symbols]

21 is a two-point press, 22 is a variable stroke device,
23 is a frame, 24 is a main pin, 25 is a main gear, 25A is a groove, 26 is a first eccentric bush, 26A is an outer circular portion, 26B is an inner circular portion, 27 is a second eccentric bush,
27A is an outer circle, 27B is an inner circle, 28 is a connecting rod, 28A is the other end of the connecting rod 28, 29 is a slide, 30 is a pin, 30A is a slider,
31 is a large gear, 31A is a screw, 31B is a groove, 32 is a pinion, 33 is a drive shaft, 34 is a drive shaft, 35 is a drive gear, 36 is a flywheel, 37 is a clutch / brake, 38 is an encoder, and 39 is a disc. , 40 are cylinders, 41 is a brake, 42 is a stopper, 43 is a main motor, 44 is a C frame press, and a and b are cylinders 40.
, L is the moving distance, e1 is the amount of eccentricity of the center O1 of the outer circular portion 26A, e2 is the amount of eccentricity of the center O2 of the outer circular portion 27A, O is the center of the main pin 24, O1 is the first bush 2
6, O2 is the center of the outer circumferential portion 27A of the second bush 27. O2 is the center of the outer circumferential portion 2A.

Claims (2)

[Claims] 1. A variable stroke device for a mechanical press, comprising: a) a main pin having means for maintaining a rotation stop position; b) a main gear fixed concentrically to the main pin and driven by a drive source; A first eccentric bush rotatably fitted to the main pin with an inner circular part eccentric to the circular part; d) an inner circular part eccentric to the outer circular part about the outer circular part of the first eccentric bush; A second eccentric bush, which is engaged with the main gear, rotates integrally with the main pin, and raises and lowers a slide by a connecting rod rotatably fitted to the outer circumferential portion; Concentrically and rotatably fitted to the pin,
A) a large gear having the same diameter and the same number of teeth as the main gear locked with the first eccentric bush; and f) a pinion that meshes with the main gear and the large gear, and is axially movable, and the pinion is A drive shaft that is driven and controlled to two positions engaged with and disengaged from the main gear;
G) a detector for directly or indirectly measuring the rotation angle of the first eccentric bush, and driving control of the drive shaft in the axial direction while maintaining the main pin at the rotation stop position. A variable stroke device for a mechanical press, wherein a pinion and the main gear are disengaged from each other, and the first eccentric bush is rotated to change the rotation phase of the second eccentric bush. 2. The gear according to claim 1, wherein the first eccentric bush is locked or fixed to the main pin, the second eccentric bush is engaged with the large gear, and the rotation stop position of the large gear is maintained. A variable stroke device for a mechanical press.