JPH05245696A - Scotch yoke press - Google Patents

Abstract

PURPOSE:To obtain a Scotch yoke press applicable to a forging work in which the stroke is long and the load is large. CONSTITUTION:The sliding surfaces 21, 22, which are parallel in upper and lower sides, of a sliding chamber 23 piercing a ram 2 are inclined against a horizontal line, and the lowering direction is coincided with the rotary direction of an eccentric shaft 4. A deflection of distance K is provided between the center R of a main shaft 5 and the central line Y of the ram 2. A guide block 6 that is slidable obliquely is fitted into the ram 2 together with a position adjusting device 7, and the Scotch yoke 3 is fitted freely slidably into this block guide. The press is provided at least with one of the three structures above. Thus, 1. the horizontal component of the load from the ram to the ram guides 11, 12 is reduced. 2. The couple to rotate the ram guide is made small. 3. A direct load on the adjusting device is avoided. Consequently, the horizontal rigidity of the press is greatly reinforced, and the forging work with the heavy load with a long stroke is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is a new technology relating to a Scotch yoke press.

[0002]

2. Description of the Related Art FIG. 6 schematically shows a conventionally used Scotch yoke press. As shown in the drawing, a ram 2a vertically constrained by ram guides 11a and 12a provided on the front and rear surfaces of the press frame 1a and a sliding surface 21a and 22a that are vertically parallel to each other and are bored in the ram are opposed to each other. Of the scotch yoke 3a sandwiched between the sliding surfaces 21a and 22a and slid into the sliding chamber 23a, an eccentric shaft 4a penetrating through the scotch yoke 3a, and a distance from a center R of the eccentric shaft. Generally, the main shaft 5a has a center R separated by E and rotates integrally. This scotch yoke press is difficult to maintain the accuracy of the product because the conventional clamp press has a large number and types of moving members and a complicated structure, and it also complicates the inertia of motion and is difficult to control. In particular, the overall height is small due to the absence of connecting rods, and the advantage of being able to simplify and downsize the equipment has been highly evaluated, and it is most suitable for high-speed and light-load mass-pressing work such as punching small electronic parts. It is becoming popular as a suitable device.

Even in the case of the Scotch yoke press, the upper die is attached to the bottom of the ram, and the material is sandwiched between the lower die and the lower die placed on the base of the apparatus to press the die. It goes without saying that the product of the correct size cannot be obtained if the accuracy of raising and lowering with respect to the ram, that is, the rattling and the distortion of the ram with respect to the ram guide. At the same time, the load applied when the ram acts on the material will also differ depending on the shape of the product and its thickness, so the position of the bottom dead center (die height) of the ram is adjusted so that the most appropriate load is applied to the material. Must. FIG. 6 shows an example of this adjusting mechanism, and shows the bottom surface 2 of the ram 2a.
4a, the wedge holder 101 is biased so as to be slidable up and down, and the lower wedge 102 and the upper wedge 103 which are engaged with each other on the inclined surface are overlapped with each other in the wedge holder, and the side surface of the lower wedge is wedged. It has a female screw 105 which is screwed to a male screw 104 having a rotary shaft protruding out of the holder. Therefore, when the rotary shaft is rotated, a wedge action is generated by the screw advancement and moves upward or downward against the urging force, and the distance from the center R of the main shaft to the bottom surface of the wedge holder 101 is increased or decreased.

FIG. 7 is quoted from Japanese Examined Patent Publication No. 63-64280, in which a crank pin metal 3b (Scotch choke) is constructed so as to be slidable.
slanted contact portions 21b, 22b formed on or disposed in b
It is configured so that it is fitted to the position of the, and is inclinedly arranged at a predetermined angle in the rotation direction. Since the crankpin metal 3b is provided in the ram 2b in a state of being inclined at a predetermined angle θ with respect to the horizontal plane, the component force P1 of the pressing force P applied to this inclined surface causes the ram 2b to move to the crankshaft (main shaft). 5
During the movement of b, it is constantly pressed in the direction of the arrow (right side), and is vertically moved in a state of being in contact with the frame 1b at the sliding contact surface M. Since such a pressing force acts unilaterally, it is said that a product with high dimensional accuracy can be obtained by eliminating rattling that easily occurs between the ram and the frame and moving the ram up and down at an accurate position.

[0005]

In the prior art shown in FIG. 6, the total load applied from the ram to the mold is directly applied to the member that adjusts the distance from the center R to the bottom surface of the wedge holder. There is a problem that this portion will be destroyed or deformed unless it has sufficient rigidity to withstand this load. Further, since there are not a few kinds of members in this portion and the accuracy thereof is also required to be high, the structure becomes complicated accordingly, and the total height increases, which is not preferable. In particular, if the applicable conditions of the Scotch yoke press are widened and a stroke longer than that of the conventional one is set and it is intended to be used for press work with a correspondingly large load, this point becomes a major obstacle.

More preferably, as the load on the main shaft 5 increases, the problem of ensuring the safety of the device itself and the operator becomes more important. Therefore, when the Scotch yoke press is to be used under heavy load, One of the challenges is that it has a control system that can automatically detect the load of the press or respond automatically when an unexpected overload occurs due to an unexpected state. Come up.

The conventional technique shown in FIG. 7 is characterized in that the direction of rotation of the eccentric shaft coincides with the direction in which the crank pin metal (Scotch yoke) rises diagonally, and the load applied from the ram to the mold. It can be appreciated that the horizontal component force is concentrated in one direction (right side in the drawing) to eliminate the rattling between the ram guide 11b and the ram to eliminate rattling and improve the dimensional accuracy in the horizontal direction. However, as described above, such a mode of use is particularly suitable when the Scotch yoke press of extremely high speed has a small stroke and a small load, but is suitable for mass production.
For use with large strokes and increased loads, another challenge will be encountered. That is, as the load increases, the horizontal component force that pushes the ram against the ram guide 11b also increases, and the proportion thereof increases as the tilt angle at which the crank pin metal (Scotch yoke) 3b slides and increases. Therefore, as compared with the conventional Scotch yoke press (for example, the model shown in FIG. 6), unless the press frame 1b holding the ram has a structure with higher rigidity, the press frame 1b will not be able to withstand and will be damaged, and the accuracy will be greatly improved. It is easy to cause it to fall.

In order to solve the above-mentioned problems, the present invention does not require a structure having excessive rigidity and is relatively lightweight and has a simple structure even under a condition of relatively long stroke and large load. The purpose is to provide the Scotch York Press.

[0009]

The scotch yoke press according to the present invention is a ram 2 which is constrained by ram guides 11 and 12 on front and rear surfaces provided on a press frame 1 and vertically moves vertically.
A scotch yoke 3 which is bored in the ram and vertically slid into the hollow sliding chamber 23 where the sliding surfaces 21 and 22 are opposed to each other. An eccentric shaft 4 penetrating through the yoke 3 and internally fitted, and a main shaft 5 having a center R separated by a distance E from a center Q of the eccentric shaft and rotating integrally.
And the upper and lower sliding surfaces 21, 2
The above problem was solved by the fact that 2 forms an inclination angle with the ram bottom surface 24, and the rotation direction of the eccentric shaft and the oblique descending direction of the sliding surface coincide with each other. In addition to this configuration, the spindle 5
It is further effective to solve the problem that a deviation of the distance K is formed between the center R of the ram 2 and the center line Y of the ram 2. Furthermore, the scotch yoke 3 is not directly fitted into the ram, but a guide block 6 which can be slidably adjusted along the slanted sliding surfaces 61 and 62 is fitted into the ram, and the scotch yoke 3 is fitted into the guide block 6. A complicated configuration is also effective in solving problems.

Each of the above three basic requirements may be an independent structure based on the basic requirements, but various additional forms can be obtained by adding supplementary requirements to these or by combining some of them. For example, the third structure is added to the first structure or the structure obtained by adding the second structure to the first structure, and it is slidable in the sliding surfaces 61 and 62 that are inclined parallel to each other vertically in the ram 2. The guide block 6 is sandwiched between the guide block 6 and the sliding surfaces 21 and 22 which are slanted vertically parallel to the guide block 6 to face each other, and the Scotch yoke 3 is slidably sandwiched between the sliding surfaces 21 and 22. At the same time, it is effective that the ram 2 is provided with the adjusting device 7 for sliding the guide block 6 and the driving of the adjusting device 7 and the operating condition of the ram 2 are adjustably attached. When the second configuration is adopted, the case without the first configuration, that is, the upper and lower sliding surfaces 21 and 22 of the ram 2 may be parallel to the ram base 24. Also in the configuration in which the drive device is attached to the ram 2, sliding surfaces 21 and 22 that are parallel to each other in the vertical direction and that are parallel to the ram bottom 24 are formed in the guide block 6 that is inclined and sandwiched in the ram. A configuration is also possible.

[0011]

In order to solve the problems of the present invention, there are three basic configurations, and three basic actions based on this are realized. Then, many configurations and operations that combine these basics are derived and developed into various embodiments. Figure 3
Shows the first action and is one of the embodiments. The ram 2 is sandwiched between both ram guides 11 and 12 of the press frame 1 and is constrained to move up and down. A slide chamber 23 having upper and lower inclined sliding surfaces 21 and 22 is formed in the ram, and the inclination angle is α. The scotch yoke 3 is fitted in this chamber and slidably slides along the sliding surfaces 21 and 22. One of the major characteristics is that the eccentric shaft rotates in the direction in which the scotch yoke 3 descends obliquely. It is the point that agrees with. That is, since the center Q of the eccentric shaft rotates about the center R of the main shaft 5 with the eccentric distance E, the scotch yoke 3 slides down along the sliding surfaces 21 and 22 of the ram 2, and the scotch yoke moves vertically. A deviation based on the angle α occurs from the maximum sliding position. When the sliding distance is S, the eccentric distance E is expressed by E = S / 2 × cos α, and the relationship that the eccentric amount of the eccentric shaft is reduced by that much is established.

Now, letting the pressing force of the press be P, the horizontal component of the pressing force on the inclined surface is F1, and the horizontal component of the frictional force acting between the scotch yoke 3 and the sliding surfaces 21, 22 is F2. Then, the horizontal component force applied to the ram is represented by | F1-F2 |, and when this is F3, F1 = P × tanα and F2 = P × μ can be almost obtained by appropriately selecting the inclination angle α. By making them equal, the horizontal component force F3 applied to the ram
Can be made as small as possible. In a normal forging press, the pressing force P is a huge value of 1000 to 3000 tons, and the pressing force component F1 and the frictional resistance force horizontal component F2 are very large forces.
Since it causes the press frame 1 to be deformed via the Nos. 1 and 12, if this action is appropriately used, there is a possibility that the Scotch yoke press which can be executed only for a light load in the past can be applied to a heavy load forging work. open.

FIG. 4 is a diagram showing the second operation of the present invention, which is one of the embodiments. In the case of this figure, the sliding direction of the scotch yoke 3 is horizontal, and the inclination angle α is 0, so the above-described action does not occur. The feature in this case is that a deviation K is provided between the center line Y of the press frame 1 and the ram 2 and the center R of the main shaft 5. If the horizontal distance between the center R of the main shaft 5 and the center Q of the eccentric shaft is M when the position of the ram is N mm above the bottom dead center, the ram rotates counterclockwise around the eccentric shaft 4. The couple F3 that tries to make it act is expressed by (M−K) × P / L, and when this reaches the position of the bottom dead center, the couple F4 = K × P / L tries to rotate the ram clockwise. work. That is, while the center Q of the eccentric shaft descends N mm and reaches the bottom dead center where the pressing force P has the maximum value, the couple force applied to the ram guides 11 and 12 is always reduced by K, which is an effective action for the maintenance of the device. Express.

FIG. 5 shows one of the embodiments, and a load adjusting device will be illustrated based on this drawing. The scotch yoke 3 does not have a sliding chamber directly in the ram, but a guide block 6 that can be slid at an inclination angle β is fitted in the ram, and the scotch yoke 3 that slides in this guide block 6 is inserted. It is fitted. The position of the guide block 6 is made up of a female screw 71 provided on one side of the guide block 6 and a drive device 73 which is screwed onto the female screw 71 and rotates a male screw 72 attached to the ram 2. The guide block 6 is driven by driving the drive device 73.
Move to a suitable position and fix at that point. By this action, the distance between the center R of the main shaft 5 and the bottom surface 24 of the ram is adjusted, and the most suitable position of the die height is selected.

[0015]

FIG. 3, FIG. 4, and FIG. 5 are each one of the basic embodiments of the present invention, and many combinations are required with these as starting points. FIG. 1 has all of these three requirements and is a typical embodiment. Further, FIG. 2 is an exploded perspective view of the main part of the same embodiment. In the figure, both side surfaces of the ram 2 are constrained by ram guides 11 and 12 attached to the press frame 1 so as to maintain accurate linear movement in the vertical direction.
The bottom side 24 of the ram faces the bed surface 13 of the press frame 1, and molds 14 and 15 for molding are mounted in this space. Sliding surfaces 61, 62 are provided in the ram 2 which penetrate in the left-right direction and are parallel to each other and intersect the horizontal plane at an angle β. The guide block 6 is slidably fitted along the sliding surfaces 61, 62 to guide the guide. The adjusting device 7 is engaged in the left corner of the block 6.

In the case of this embodiment, unlike FIG. 5, the adjusting device 7 has an automatic control function. That is, the inside of the cylinder is moved by the piston connected to the rod 75 of the fluid pressure cylinder 74 mounted on the ram parallel to the angle β.
It is divided into two rooms, 6, 77. While the fluid pressure in the divided two chambers is kept constant, the guide block 6 does not move and remains fixed. When the eccentric shaft is stopped at the upper limit of the ram, the fluid pressure in the two chambers 76 and 77 is controlled to move the piston. For example, when the piston is moved to the right side in the figure, the rod 75 moves the guide block 6
To the right. As a result, the guide block 6 and the ram 2 are moved downward and the ram is lowered. For example, if (α + β) is 10 degrees, tan (α + β)
Is 0.176, so that only 1 / 5.67 of the moving distance of the guide block operates as the ram descending distance, which is an advantage that the ram descending distance can be finely adjusted.

Further, since the pressure detector 78 is attached to the fluid pressure cylinder 74, the force P by which the ram 2 presses the work can be changed into a hydraulic pressure for checking, and an abnormality can occur between the die and the work. When the pressing force P of the ram rises abnormally due to the occurrence of the ram, the work is stopped, the liquid in the one chamber 76 in the cylinder is discharged to raise the ram, and the excessive pressure is released to damage or deform the device. It has a function to prevent this.

Many configurations are conceivable in which the embodiment of FIG. 1 is used as the apex and only certain requirements among them are removed, but any combination can be used if any one of the above three requirements is provided. Needless to say, belongs to the technical scope of the present invention.

[0019]

As described above, the present invention has three structural features, and three special effects are produced by this configuration. Among them, by selecting the sliding direction of the scotch yoke 3, an effect of canceling out the horizontal component force applied from the ram to the ram guides 11 and 12 can be obtained, and the lateral rigidity of the press frame 1 can be improved. Only by reducing the weight of the entire press, it is possible to operate under press conditions with a larger load. Further, since the deviation K is provided between the center of the ram and the center R of the main shaft 5, the ram guides the ram guide 11,
The couple force to rotate 12 is reduced, which also improves the lateral rigidity of the press frame 1 or leads to the realization of a Scotch yoke press capable of working with a heavier load. By obliquely fitting the guide block 6 in which the Scotch yoke 3 is fitted into the ram and adjusting the position of the guide block 6 from the side surface of the ram, it is not necessary to consider the rigidity of the adjusting device itself. In addition to being simple, fine adjustment becomes easy and the die height can be set to the most appropriate operating condition even under heavy load. In addition, by incorporating the load detection signal into the electric control, the quality of the press product, mold abnormality, heating condition of the forging material, etc. can be automatically grasped to automate the press work and automatically in case of an abnormal situation. To improve the safety of heavy work and the maintenance of the equipment. Further, since the stroke length S of the ram is larger than the eccentric distance of the eccentric shaft, the eccentric distance can be reduced as compared with a Scotch yoke press having the same stroke length, and the crankshaft, the Scotch yoke 3, the guide block 6, etc. The size and shape can be reduced, and the result contributes to the reduction in weight and size of the press.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a main part of the same embodiment.

FIG. 3 is a vertical sectional front view showing another embodiment.

FIG. 4 is a vertical sectional front view showing still another embodiment.

FIG. 5 is a vertical sectional front view showing still another embodiment.

FIG. 6 is a vertical sectional front view illustrating a conventional technique.

FIG. 7 is a vertical sectional front view showing another conventional technique.

[Explanation of symbols]

1 Press frame 2 Ram 3 Scotch yoke 4 Eccentric shaft 5 Spindle 5 Guide block 7 Adjuster 11 Ram guide 12 Ram guide 21 Sliding surface 22 Sliding surface 23 Sliding chamber 24 Bottom surface 61 Sliding surface 62 Sliding surface R Spindle 5 Center Q of the eccentric shaft 4 E eccentric distance K deviation of the ram center line Y from the center of the eccentric shaft Y ram center line α Inclination angle formed by the sliding direction of the Scotch yoke 3 and the horizontal line β Guide block 6 Angle formed by the sliding direction and horizontal line

Claims (5)

[Claims] 1. A ram 2 constrained by front and rear ram guides 11 and 12 provided on a press frame 1 to vertically move vertically.
A scotch yoke 3 which is bored in the ram and vertically slid into the hollow sliding chamber 23 where the sliding surfaces 21 and 22 are opposed to each other. An eccentric shaft 4 penetrating the yoke 3 and fitted therein, and a center R of the eccentric shaft 4.
In a Scotch yoke press composed of a main shaft 5 having a center Q separated by a distance E from and rotating integrally, the upper and lower sliding surfaces 21 and 22 form an inclination angle with a ram bottom surface 24,
The scotch yoke press is characterized in that the rotation direction of the eccentric shaft and the slanting direction of the sliding surfaces 21 and 22 coincide with each other. 2. The scotch yoke press according to claim 1, wherein a deviation of a distance K is formed between a center R of the main shaft 5 and a center line Y of the ram 2. 3. The sliding surface 61, 62 according to claim 1 or 2, which is provided in the ram 2 and is inclined in parallel and vertically opposed to each other.
Sliding surfaces 21 and 2 which sandwich the guide block 6 slidably inward and incline and oppose the guide block 6 in a vertically parallel manner.
2 is provided, the scotch yoke 3 is slidably sandwiched between the sliding surfaces 21 and 22, and an adjusting device 7 for moving the guide block 6 is provided on the ram 2 to drive the adjusting device 7 and the ram 2. A scotch yoke press characterized in that it is attached so that it can be adjusted with the operating conditions of. 4. The scotch yoke press according to claim 2, wherein the upper and lower sliding surfaces 21, 22 of the ram 2 are parallel to the ram bottom side 24. 5. The ram bottom 2 according to claim 3, wherein the ram base 2 is vertically parallel in the guide block 6 that is inclined and sandwiched in the ram.
A scotch yoke press characterized in that sliding surfaces 21 and 22 parallel to 4 are provided.