JPH07115227B2 - Scotch yoke press - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art An outline of a conventionally used Scotch yoke press is shown in FIG. As shown in the figure, a ram 2a that is vertically constrained by ram guides 11a and 12a provided on the front and rear surfaces of the press frame 1a and a vertically parallel sliding surface 21a and 22a that are bored in the ram face 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 compensates for the drawbacks of conventional clamp presses, in which it is difficult to maintain the accuracy of the product due to the large number and types of moving members and the complicated configuration, and the inertia of movement is also difficult to control. In particular, the overall height has been reduced due to the lack of a connecting rod, 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 surface 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 if the accuracy of raising and lowering with respect to the ram, that is, the rattling and distortion of the ram with respect to the ram guide, cannot be obtained, the product of the correct size cannot be obtained. 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. A female screw 105 that is screwed with a male screw 104 having a rotating shaft protruding out of the holder is provided. 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 in the position of, and is inclined 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 ram 2b is moved to the crankshaft (main shaft) by the component force P1 of the pressing force P applied to this inclined surface. 5
During the movement of b, it is constantly pressed in the direction of the arrow (right side) and is moved up and down 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 it is possible to obtain a product with high dimensional accuracy by eliminating the 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, and There is a problem that this portion will be destroyed or deformed unless it has sufficient rigidity to withstand this load. In addition, 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 and the overall height increases, which is not preferable. In particular, if the conditions to which the Scotch yoke press is applied are expanded and a longer stroke is set than that in the past, 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 spindle 5 increases, the problem of ensuring the safety of the device itself and the operator becomes more important. Therefore, when using the Scotch yoke press 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 figure) 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 endure and will be damaged, or the accuracy will be greatly reduced. 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 a good Scotch York Press.

[0009]

A 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 which vertically moves vertically.
And a scotch yoke 3 which is bored in the ram and vertically slid into a hollow sliding chamber 23 where the sliding surfaces 21 and 22 are opposed to each other, and the scotch yoke 3 is held by the sliding surfaces 21 and 22 and slides. An eccentric shaft 4 penetrating through the yoke 3 and internally fitted, and a main shaft 5 having a center R separated from the center Q of the eccentric shaft by a distance E 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
A deviation of the distance K between the center R of the ram 2 and the center line Y of the ram 2 is further effective in solving the problem. Further, the scotch yoke 3 is not directly fitted into the ram, but the guide block 6 which can be slidably adjusted along the slidable sliding surfaces 61 and 62 is fitted into the ram, and the scotch yoke 3 is fitted into the guide block 6. The complicated configuration is also effective in solving the problem.

Each of them may have an independent structure based on the above three basic requirements, but various additional forms can be obtained by adding supplementary requirements or 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 in parallel and are opposed to each other formed in the ram 2. The guide block 6 is sandwiched between the guide blocks 6, and sliding surfaces 21 and 22 are formed so as to incline vertically to the guide block 6 and 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 an adjusting device 7 that slides the guide block 6, and the drive of the adjusting device 7 and the operating condition of the ram 2 are attached so as to be adjustable. In the case of adopting the second configuration, 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 vertically parallel and parallel to the ram bottom 24 are bored in the guide block 6 that is inclined and held 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 slidable sliding surfaces 21 and 22 is formed in the ram, and the slant angle is α. The Scotch yoke 3 is fitted into this chamber and slidably slides along the sliding surfaces 21 and 22. One of the major features is that the eccentric shaft rotates in the counterclockwise 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. If 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 has a huge value of 1000 to 3000 tons, and the pressing force component F1 and the frictional resistance horizontal component force F2 are very large forces.
Since it causes the press frame 1 to be deformed via the Nos. 1 and 12, there is a possibility that the Scotch yoke press, which has been conventionally applicable only to a light load, can be applied to a heavy load forging work by appropriately utilizing this action. open.

FIG. 4 is a diagram showing the second action 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 reaches 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 composed of a female screw 71 provided on one side of the guide block 6 and a driving 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 driving 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, but many combinations are required with these as starting points. FIG. 1 is a typical example in which all these three requirements are satisfied. Further, FIG. 2 is an exploded perspective view of a 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 that an accurate linear movement in the vertical direction can be maintained.
The bottom side 24 of the ram faces the bed surface 13 of the press frame 1, and molding dies 14 and 15 are mounted in this space. The ram 2 is provided with sliding surfaces 61, 62 penetrating in the left-right direction in parallel with each other and intersecting a horizontal plane at an angle β, and 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 stops 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)
Since 0.176 is 0.176, 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 to a hydraulic pressure for checking, and an abnormality is generated between the die and the work. When the pressing force P of the ram rises abnormally due to the occurrence of the pressure, 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.

Although many configurations are conceivable in which the embodiment of FIG. 1 is used as the apex and only certain requirements among them are removed, any combination can be used in the case where 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, and by that amount. 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 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 performing a heavier load. By obliquely fitting the guide block 6 with the Scotch yoke 3 fitted in 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, the mold abnormality, the heating condition of the forging material, etc. can be automatically grasped to automate the press work and to automatically detect when an abnormal situation occurs. To improve the safety against heavy-duty 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 made smaller than that of the 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 is that it contributes to the weight reduction 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 a perspective view showing a disassembled 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 6 Guide block 7 Adjuster 11 Ram guide 12 Ram guide 21 Sliding surface 22 Sliding surface 23 Sliding chamber 24 Bottom 61 Sliding surface 62 Sliding surface R Spindle 5 Center Q center of eccentric shaft 4 E eccentric distance K deviation between center line Y of ram and center of eccentric shaft Y ram center line α Inclination angle formed by sliding direction of Scotch yoke 3 and horizontal line β Guide block 6 Angle formed by the sliding direction and horizontal line

Claims (5)

[Claims] 1. A ram 2 vertically constrained by ram guides 11 and 12 provided on the front and rear surfaces of a press frame 1 to move vertically.
And a scotch yoke 3 which is bored in the ram and vertically slid into a hollow sliding chamber 23 where the sliding surfaces 21 and 22 are opposed to each other, and the scotch yoke 3 is held by the sliding surfaces 21 and 22 and slides. An eccentric shaft 4 penetrating through the yoke 3 and fitted therein, and a center R of the eccentric shaft 4.
In a Scotch yoke press consisting 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 descending directions of the sliding surfaces 21, 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 formed in the ram 2 and is inclined in parallel with and vertically opposed to each other.
Sliding faces 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 to the operating conditions of. 4. The scotch yoke press according to claim 2, wherein the upper and lower sliding surfaces 21 and 22 of the ram 2 are parallel to the ram bottom side 24. 5. The ram base 2 according to claim 3, wherein the ram base 2 is vertically parallel in a guide block 6 that is inclined and sandwiched in the ram.
A scotch yoke press characterized in that sliding surfaces 21, 22 parallel to 4 are provided.