JP2003320426A - Link type punch press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a link type punch press which is capable of performing a process with a high press load and shortening the cycle time of the process and is also excellent in controllability, even if a motor of a relatively small capacity is used, and which can perform a process according to required processing quality. <P>SOLUTION: The punch press is equipped with a linkage 1 which converts a rotational motion to a linear motion and a ram 6 which moves vertically to perform a press process in the linear motion, and a drive transmission system 14 is provided to transmit drive from a motor 13 to a crank shaft 3 of the linkage 1. The drive transmission system 14 can control and transmit vertical motion of the ram 6 by rotation control of the motor 13. As control means, there are provided a process sort selecting means 42 and a motor rotation direction control means 44 which changes over the normal or reverse rotation direction of the motor depending on the process sort selected by the process sort selecting means 42. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a link type punch press using a link mechanism as a slide drive mechanism.

[0002]

2. Description of the Related Art In mechanical punch presses, a crank mechanism is generally used as a slide drive mechanism for converting a rotating operation of a motor into an elevating operation of a ram. In addition, a flywheel is used to switch between driving and stopping the ram by connecting and disconnecting the rotation of the flywheel when the clutch is turned on and off. With the crank mechanism,
The curve of the ascending / descending speed of the ram is symmetrical with respect to the bottom dead center at the time of descending and ascending, and the descending speed and the ascending speed are the same. However, in general press working such as punching, when the ram descends, it is preferable to make it low speed because of the requirement of noise reduction and press load, but when ascending, there is no particular limitation, so it is desirable to be high speed. With a crank mechanism in which the descending speed and the ascending speed are the same, it takes more time than necessary to ascend, and the punching cycle time becomes long.
Recently, a servo motor is used as a drive source, and a ram is raised and lowered via a crank mechanism without providing a flywheel. If a servo motor is used, it is possible to freely change the speed during the stroke of the ram, to increase the descending speed and decrease the ascending speed. However, the capacity of the motor changes depending on the rotation speed, and in order to make the best use of the capacity of the motor, it is necessary to operate within the range of the optimum motor rotation speed according to the motor characteristics. By controlling the motor rotation speed to change the speed when the ram descends and when it rises, it is not possible to make full use of the capacity of the motor, and in order to obtain the necessary press load and increase the speed when climbing, A large motor is required.

Therefore, the inventor of the present invention has conducted various studies on what is slowed down when moving down and fast when moving up by selecting an appropriate slide mechanism. BACKGROUND ART Conventionally, a link press has been used for a long time as a slide mechanism used in a press device for plastic working such as cold extrusion and upsetting of metal (for example, Japanese Patent Publication No. 3-42159). The link press has a swing pin connected to a crank pin of a crank mechanism, a connecting rod connected to the swing link, and a restraint link connected to the swing link. The crankshaft is driven by a motor via a flywheel. According to the link press, the operation characteristic that the ram speed is slow when descending and fast when ascending is obtained by the action of the restraining link.

However, the conventional link press is used for improving the working quality of plastic working such as cold extrusion by utilizing a very slow descending operation near the bottom dead center thereof. There is no application example to a punch press that requires operating characteristics different from those of processing. Also, because it has a flywheel that stores the motor output as inertial energy,
Lack of controllability. Further, in punching, the required processing quality differs depending on the product to be produced, and when high processing quality is required, priority is given to securing processing quality over environmental performance due to noise and vibration. In punching, the higher the punch speed, which is the ascending / descending speed of the punch die, the better the processing quality. That is, in shearing such as punching,
Higher punch speed results in higher quality processing with less burr. Therefore, when the conventional link press is applied to the punch press, it is difficult to secure the processing quality due to the low speed operation at the time of descending.

An object of the present invention is to use a link type machine capable of performing processing by a high press load and improving the cycle time of the processing even if a motor having a relatively small output is used, and which can perform processing according to the required processing quality. It is to provide a punch press.

[0006]

The structure of the present invention will be described with reference to FIG. 1 corresponding to the embodiment. This link type punch press has a motor (13), a link mechanism (1) for converting a rotational motion transmitted from the motor (13) through a drive transmission system (14) into a linear motion, and the link mechanism ( A ram (6) which is installed below 1) and moves up and down for press work by the above linear motion, and the following control means are provided. The link mechanism (1) is provided with a crank member (2) having a crank shaft (3) and an eccentric shaft portion (4), and first to third connecting portions (P1 to P) that rotatably connect the crank member (2).
3) so as to be located at each vertex of the triangle,
A swing link (5) having a first connecting portion (P1) connected to the eccentric shaft portion (4) of the crank member (2), a second connecting portion (P2) and the upper ends of the rams (6). A connecting rod (7) having both ends connected to and a base end rotatably connected to the frame (9) and a front end connected to the third connecting portion (P3) of the swing link (5). A restraint link (8) for restricting swing of the swing link (5). As the control means, a machining type selecting means (42) for selecting a type relating to the quality of the drilling process, and a forward and reverse rotation of the motor (13) according to the machining type selected by the machining type selecting means (42). And a motor rotation direction control means (44) for switching the direction.

The operation of this configuration will be described. Due to the rotation of the crankshaft (3), the swing link (5) revolves in the orbital motion of the eccentric shaft portion (4) along the orbit of the center of the eccentric shaft portion (4), and the restraint link (8) is connected so that the swing link (5) is reversed. Performs a combined action with the shaken rotation movement. The revolving motion of the rocking link (5) causes the connecting rod (7) connected thereto to ascend and descend, but because of the above-described rotation movement, the lower end position of the connecting rod (7), that is, the ram position ascends and descends. The velocity curve does not become a quasi-sine curve, but becomes asymmetric between the descent and the ascent. Which of the descending speed and the ascending speed becomes faster is determined by a combination of various elements such as the fulcrum position and length of the restraint link (8). Therefore,
By properly designing each element, the restraint link (8) swings so that the descending motion of the ram (6) when the crankshaft (3) is rotated in one direction at a constant speed is slower than the ascending speed. The swing of the dynamic link (5) can be restricted. In this way, by lowering the descending speed, it is possible to perform processing with a high press load even when using the motor (13) having a relatively small output, and the ascending speed becomes faster, so that the machining cycle time is improved. To do. Since the above-mentioned speed change is given while the motor speed remains constant, for example, by interposing a speed reducer having an appropriate speed reduction ratio, it is possible to operate at the motor rotation speed that maximizes the motor output according to the motor characteristics. This also makes it possible to use the motor (13) having a small output.

Further, a machining type selecting means (42) and a motor rotation direction control means (44) for switching the forward and reverse rotation directions of the motor (13) according to the machining type selected by the machining type selecting means (42). Therefore, the control for switching the rotation direction of the motor (13) can be performed depending on the required processing type. The above-described operation of slowing down the speed is effective in the case of punching of normal quality. When high processing quality is required, processing type selection means (4
By selecting a predetermined machining type (for example, high-quality machining) according to 2), the motor rotation direction control means (44) causes the rotation direction of the motor (13) for driving the crankshaft (3) to be the same as during normal operation. Switches in the opposite direction. In the case of this reverse rotation, the link mechanism (1) performs an operation in which the ram speed when descending is higher than the ram speed when ascending when the motor rotation speed is constant. In this way, the lowering operation of the ram (6) becomes faster, so that the punching performed by the punch tool becomes higher in quality than the driving of the ram (6). That is, it is possible to perform drilling with less burr. However, in this case, since a large press load cannot be obtained, it is not possible to perform plate work with a large plate thickness or drilling with a large diameter. That is, it is possible to freely select a normal machining which can machine a thick plate work or a large-diameter hole with high machining efficiency and a high-quality machining which is limited in efficiency, plate thickness and hole diameter.

The drive transmission system (14) includes a motor (1
The rotation drive of the motor (13) may be transmitted to the crankshaft (3) so that the raising and lowering operation of the ram (6) can be controlled by the rotation control of 3). This drive transmission system (14) does not include a flywheel or any other component for imparting inertia, and even if it has a speed reducer,
Further, the output shaft of the motor and the crank shaft may be directly connected. The motor (13) may be a servo motor. When the drive transmission system (14) has this structure, the motor (13) and the crankshaft (3) are connected via the drive transmission system (14) without any interposition of components such as a flywheel for the purpose of imparting inertia. Therefore, the controllability such as changing the ram speed by controlling the rotation speed of the motor (13) is excellent. Further, when the motor (13) is a servomotor, the motor speed can be freely changed, so that the speed during the up-and-down stroke of the ram (6) can be changed, and machining according to various requests can be performed. You can do it. That is, as a speed curve when the motor (13) is rotated at a constant speed, the operation of the link mechanism (1) including the crank member (2), the swing link (5), the restraint link (8), etc. By changing the motor speed based on the following speed curve, it is possible to further reduce the speed when the punch tool contacts the plate work to further reduce noise, or to increase the speed when rising. Is.

When the motor (13) is a servomotor, the motor rotation direction control means (44) causes
Motor rotation speed control means (45) for increasing the motor rotation speed so that the descending speed of the ram (6) is further increased in the state of the motor rotating direction in which the descending speed of the ram (6) is faster than the ascending speed. May be provided. The motor rotation speed control means (45) controls to increase the motor rotation speed when the ram descends, for example, according to the processing type selected by the processing type selection means (42). In this way, by further increasing the descending speed of the ram (6), it is possible to perform drilling with higher quality. Although the restrictions on the plate thickness and hole diameter will become more severe, if it is within the allowable range, high-quality machining one rank higher can be performed. The motor rotation speed control means (45) speeds up the speed of the entire section of the crank member (2) during one rotation in order to increase the motor rotation speed so that the descending speed of the ram (6) becomes faster. As well as one of the crank members (2)
It is also possible to accelerate only the section when the ram descends during rotation.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram combining a link mechanism and a block diagram showing a conceptual configuration of a control system in the link type punch press. The control system will be described later.
This link type punch press is provided with a motor 13, a link mechanism 1 for converting a rotary motion transmitted from the motor 13 via a drive transmission system 14 into a linear motion, and a linear mechanism installed below the link mechanism 1. And a ram 6 that moves up and down for press working. The link mechanism 1 includes a crank member 2 having an eccentric shaft portion 4 which is eccentric with respect to the axis of the crank shaft 3, a swing link 5 connected to the eccentric shaft portion 4, a connecting rod 7, and a restraining link 8. Have. The crankshaft 3 is rotatably installed on the frame 9 and serves as a shaft that receives a rotational driving force. Eccentric shaft part 4
Is a shaft portion having a diameter larger than that of the crankshaft 3. The eccentric shaft portion 4 may have a smaller diameter than the crankshaft 3 and may be integrated with the crankshaft 3 via a crank arm (not shown), instead of having the large diameter as described above. The ram 6 is a member for raising and lowering a press working portion such as a punch tool, and is installed on the frame 9 via a guide member 10 so as to be able to move up and down. Ram 6 is
It is directly below the crankshaft 2.

The swinging link 5 has first to third connecting portions P1 to P3, and the crank member 2 is connected to the first connecting portion P1.
Is connected to the eccentric shaft portion 4. Each connecting portion P1-3
Each of them is a connecting portion for rotatably connecting and is located at each vertex of the triangle T, as schematically shown in FIG. This triangle T is an arbitrary triangle in a plane perpendicular to the axis of the crankshaft 3. In FIG. 1, the connecting rod 7 is the second connecting portion P of the swing link 5.
The upper end is connected to 2 and the lower end is rotatably connected to the upper end of the ram 6 via a pin 11. The restraint link 8 has a base end rotatably supported by the frame 9 via a fulcrum shaft 12,
The tip is connected to the third connecting portion P3 of the swing link 5. The restraint link 8 is arranged such that the swing center, which is the axial center of the fulcrum shaft 12, and the third connecting point P3 are distributed to both sides of the crankshaft 3. The both sides are both sides in a plane perpendicular to the axis of the crankshaft 3, and may be on both sides in the left-right direction or both sides in the front-rear direction with respect to the entire link type punch press. .

As shown in FIGS. 4 and 5, the crankshaft 3 has a drive transmission system 14 connected to an output shaft (not shown) of the motor 13.
Are connected via. The drive transmission system 14 is the motor 1
It is assumed that the rotation drive of the ram 6 can be controlled by the rotation control of the motor 3, and the rotational drive of the motor 13 can be transmitted to the crankshaft 3. Therefore, the drive transmission system 14 is a means for transmitting the torque of the motor 13 without interposing components such as a flywheel for imparting inertia. In this embodiment, the drive transmission system 14 includes a speed reducer 15 and a coupling 16 that connects the output shaft of the speed reducer 15 to the crankshaft 3.
A servo motor is used as the motor 13. The speed reducer 15 and the motor 13 may be integrated with each other to form a motor with a speed reducer.

FIG. 2 shows a broken side surface of the link mechanism 1.
The crankshaft 3 extends on both sides of the eccentric shaft portion 4, and is rotatably supported on the frame 9 on both sides via bearings 17 such as journal bearings. In the swinging link 5, the inner diameter surface of the connecting hole forming the first connecting portion P1 is fitted to the outer periphery of the eccentric shaft portion 4 via the liner 18. Second of swing link 5
The connecting portion P2 and the connecting rod 7 are connected by a connecting pin 19.

As shown in FIG. 5, the frame 9 is an independent link portion frame that supports the link mechanism 1, and is attached to the tip of the upper frame portion 22a of the main body frame 22. The link frame 9 has a box shape. The frame 9 supports both ends of the crankshaft 3 by a support plate 9b provided on the inner surface of the mounting substrate 9a and a counter plate 9c facing the support plate 9b. The frame 9 has a motor support member 23.
The motor 13 is installed on the motor support member 23. Therefore, the motor 9 is connected to the link mechanism 1
Together with the link frame 9 in which the
It is removably attached to the 2. Body frame 2
2 has a C-shaped side surface, and its opening 24 is
It is the space where the plate work and tool support enter. The body frame 22 has a pair of opposing side plates, and only one opposing side plate is shown in FIG. Upper frame part 2
In 2a, the opposite side plates on both sides are the upper frame lower surface plate 2
5 and the intermediate reinforcing plate 26 are joined to each other.

10 and 11 are respectively a plan view and a side view of the whole link type punch press equipped with the link mechanism 1 of FIG. The body frame 22 is covered with a body cover 30. In addition to the link mechanism 1, a tool supporting means 28 and a work feeding means 29 are installed on the main body frame 22. The tool supporting means 28 has a plurality of punch tools 31 and die tools 32 mounted thereon, and is capable of indexing arbitrary tools 31, 32 (FIG. 11) at the press working position Q by the ram 6. The tool supporting means 28 is composed of upper and lower turrets 28a and 28b on which a punch tool 31 and a die tool 32 are mounted, respectively. The work feeding means 29 moves the plate work W on the table 33 in the two orthogonal directions (X) so that an arbitrary portion comes to the press working position Q.
Axis, Y-axis). Work feeding means 2
9 includes a carriage 34 that moves back and forth (Y-axis direction), and a cross slide 35 that is mounted on the carriage 34 and moves left and right (X-axis direction), and a plurality of work holders 36 provided on the cross slide 35. The plate work W is gripped. Forward / backward movement of the carriage 34 and cross slide 3
With the horizontal movement of 5, the plate work W is fed in the biaxial direction.

The operation of the above configuration will be described. The link mechanism 1 of FIG. 1 performs the following operation, as can be seen by referring to the schematic view of FIG. 7. When the crank shaft 3 is rotated by driving the motor, the center of the eccentric shaft portion 4 of the crank member 2 is, as shown in FIG. 7, a circular orbit C1 centered on the shaft center of the crank shaft 3.
Draw. The oscillating link 5 includes the eccentric shaft portion 4 and the first connecting portion P.
Since it is rotatably connected at 1, the above-mentioned circumferential orbit C1
Perform an orbital movement in line with. Since the swing link 5 is connected to the restraint link 8 by the third connecting portion P3, its operation is restricted, and the first connecting portion P1 is associated with the revolving movement.
Performs a rotational movement that is swung in the normal and reverse directions. Due to this combined movement of the revolution movement and the rotation movement, the second connecting portion P2, which is the connecting portion of the swinging link 5 with the connecting rod 7, is
As shown in the figure, it moves along an oblique elliptical orbit C2.
The ram 6 is supported so that it can be raised and lowered only, and is connected to the second connecting portion P2 of the swing link 5 via the connecting rod 7, so that the second connecting portion P2 draws an elliptical orbit. Moves up and down by. The speed of the raising / lowering operation of the ram 6 is asymmetric between the descending time and the ascending time, as shown by the curve H in FIG. Further, the crank angle θ _BDC when the ram 6 reaches the bottom dead center BDC is a position deviated from 180 °. A curve J also shown in the figure shows the vertical displacement of the ram in a general crank mechanism and is symmetrical.

The elements that affect the operation of the link mechanism 1 are the following eight elements shown in FIG. The crank length (eccentricity) r, the length w of the restraint link 8, the length L of the connecting rod 7, the opening angle α between the connecting portions P2 and P3 of the swing link 5, and the connecting portion P1 of the swing link 5. Connection part P
The lengths a and b between 2 and P3, and the X-coordinate Ex and the Y-coordinate Ey of the fulcrum position of the restraint link 8. The center of coordinates is the axis of the crankshaft 3. As a condition for establishing the link mechanism 1, the rotation center of the crankshaft 3-the connecting portion P1-
It is necessary to establish a four-joint rotary chain that is established by using the fulcrum shaft 12 of the connecting portion P3-restraining link 8 as a connecting point between the joints, and the shortest joint is defined as the crank length r, and each of the following expressions must be satisfied. . As A = √ (Ex ^ 2 + Ey ^ 2), r + a ≦ w + A r + w ≦ a + A r + A ≦ a + w This is known as Grashof's theorem. , The displacement curve of the ram 8 can be freely designed.

Which of the descending speed and the ascending speed becomes faster is determined by the combination of the motor rotation direction and the above-mentioned respective elements. Therefore, assuming that the motor rotation direction is constant, by appropriately designing the respective elements, it is possible to perform an operation in which the descending speed of the ram 6 when the motor 13 rotates at a constant speed becomes slower than the ascending speed. By slowing the descending speed in this way, machining can be performed with a high press load even when the motor 13 having a relatively small output is used, and the ascending speed is increased, so that the machining cycle time is improved. As shown in FIG. 9 by comparing the crank type press and the link type press, when the cycle time is “10”, both the descending time and the ascending time are “5” in the crank type as shown in FIG. However, in the link type, it is possible to design so that the falling time is “7” and the rising time is “3” as shown in FIG. When the link mechanism 1 is designed in this way, the ram speed of the descending operation becomes 5/7 as slow as that of the crank type, and the press load becomes 7/5 as much, and even if the same motor is used, 40%
The press load can be improved. Since no work is performed when the ram 6 is raised, even if the force is weak, it does not affect the machining.

Further, since the above-mentioned speed change is given while the motor speed is kept constant, the speed reducer 15 having an appropriate deceleration ratio is provided.
By interposing (FIG. 4), it is possible to operate at the motor rotation speed that maximizes the motor output according to the motor characteristics. This also makes it possible to use the motor 13 with a small output.
Further, since the motor 13 and the crankshaft 3 are connected via the drive transmission system 14 in which an inertia imparting system such as a flywheel does not intervene, the controllability of changing the ram speed by controlling the rotational speed of the motor 13 is excellent.

When the motor 13 is a servo motor,
Since the motor speed can be freely changed, the speed during the up-and-down stroke of the ram 6 can also be changed, and machining according to various requests can be performed. That is, the crank member 2 is used as a speed curve when the motor 13 is rotated at a constant speed.
Based on the speed curve according to the operation of the link mechanism 1 composed of the rocking links 5, the restraint links 8 and the like, the speed when the punch tool 31 comes into contact with the plate work W is changed by changing the motor speed. It is also possible to further reduce the noise to further reduce the noise, and to further increase the speed at the time of rising. Further, the ram 6 can be stopped at an arbitrary height.

In this link type punch press, when punching is carried out, as shown in FIG.
The punching section M, which is a section used for punching, needs to be an intermediate section of the descending process of the ram lifting stroke.
The intermediate section, which is the punching section M, is a section in which the curve H of the displacement of the ram 6 with respect to the crank angle is substantially linear.
The lower limit position H ₁ of the punching section M is slightly above the die height DH. In the link press, if the motor speed is constant, as can be seen from the ram displacement curve H in the same figure, the curve becomes a gentle curve near the top dead center TDC, becomes a straight line in the middle section, and again near the bottom dead center BDC. It becomes a gentle curve. The speed near the bottom dead center BDC is the slowest, and therefore the largest press load is obtained near the bottom dead center BDC. In the conventional linking press for forming, a large press load near the bottom dead center BDC is used for forming. However, in the case of punching, a stroke is required below the lower surface of the plate work W in order to surely drop the punch residue. On the other hand, if the punching section M is the middle section of the stroke, a sufficient stroke can be obtained below the lower surface of the plate work W, and the punching scraps can be reliably dropped, and the originally small punch load in the middle section. Link mechanism 1
Can be supplemented with. In other words, for this reason, the vicinity of the bottom dead center BDC where a large press load can be obtained cannot be used, but it can be used more efficiently than the conventional symmetrically operating crank mechanism. Punching requires a large press load and high-speed processing. Further, in punching, the higher the punching speed, the better the processing quality, and the punching section M
When is the intermediate section, the punching speed required for processing quality can be obtained without waste. In this way, when applied to a punch press, the action of the link mechanism 1 can be effectively used in a usage pattern different from that of the conventional link press for molding.

In FIG. 1, a control device 41 is a device for controlling the whole of the link type punch press, and comprises a computer type numerical control device and a programmable controller which are controlled by a processing program (not shown). The control device 41 has a control means for each axis that drives the ram 6 up and down and controls the work feeding means 29 (FIG. 10), and one of them is the ram axis control means 44.
Is provided. The ram shaft control means 44 is means for controlling the motor 13 that drives the crankshaft 3 of the link mechanism 1. The ram axis control means 44 has a motor rotation direction control means 44 for switching the rotation direction of the motor 13 between forward and reverse, and a motor rotation speed control means 45 for controlling the rotation speed of the motor 13.

The control device 41 has a machining type selection means 42, and the motor rotation direction control means 44 switches the forward / reverse rotation direction of the motor 13 according to the machining type selected by the machining type selection means 42. is there. The processing type selection means 42 is a means for selecting a type relating to the quality of the punching processing, and is, for example, a means for giving information for selecting the distinction between normal processing and high quality processing. In this example, in addition to normal processing and high-quality processing, ultrahigh-quality processing can be added in three stages of selection.

The motor rotation direction control means 44 switches the forward and reverse rotation directions of the motor 13 according to the processing type selected by the processing type selection means 42. When the machining type selected by the machining type selecting unit 42 is normal machining, the motor rotation direction control unit 44 transmits the rotation of the motor 13 in the forward rotation direction, that is, the link mechanism 1, thereby the ram 6 is rotated. The motor rotation direction is such that the descending speed is slower than the ascending speed, and in the case of high-quality machining, it is the reverse rotating direction. The motor rotation direction control means 44 sets the reverse rotation direction even when the processing type selected by the processing type selection means 42 is ultra-high quality processing.

The motor rotation speed control means 45 detects predetermined information when the motor rotation direction control means 44 determines that the motor rotation direction is such that the descending speed of the ram 6 is faster than the ascending speed. It has a function of increasing the motor rotation speed so that the descending speed of 6 becomes even faster.
Regarding the control for increasing the motor rotation speed so as to further increase the descending speed of the ram, the motor rotation speed control means 45 may increase the speed of the entire section of the crank member 2 during one rotation. It is also possible to speed up only the section when the ram descends during one rotation of the member 2. The predetermined information is, for example, the processing type selection means 4
This is information that the processing type selected in 2 is ultra-high quality processing.

More specifically, the machining type selecting means 42 may be either the machining type selection information described in the machining program or the information set in the parameter setting means (not shown) or the like. It may be information input by the operator from the operation panel. The selection information of the processing type described in the processing program may be information given as a command by an NC code or the like, or attribute information. As for the type of the quality of the drilling, it is sufficient that the types of the quality of the drilling can be distinguished as a result. Information such as the material of the plate material and the type of surface treatment is recognized by the controller 41 as the selection information of the machining type, and the motor You may make it notify to the rotation direction control means 44.

The operation of the control device 41 having the above configuration will be described. When normal processing is selected by the processing type selection means 42, the motor rotation direction control means 44 rotates the motor 13 in the forward rotation direction. Therefore, as described above with reference to FIG. 8A, the ram 6 has a lower speed when descending as compared with when ascending, and drilling can be performed with low torque. When high quality processing is selected by the processing type selection means 42, the motor rotation direction control means 44 rotates the motor 13 in the reverse rotation direction.
Therefore, the ram 6 has a high descending speed as shown by the curve Ha in FIG. 8 (B). Therefore, high quality punching can be performed. That is, it is possible to perform drilling with less burr. However, in this case, since a large press load cannot be obtained, it is not possible to perform plate work with a large plate thickness or drilling with a large diameter. In this way, with high processing efficiency, normal processing that can process thick plate work and large diameter holes,
Although there are restrictions on efficiency, plate thickness, hole diameter, etc., high quality processing can be freely selected.

When ultra-high quality machining is selected by the machining type selection means 42, the motor rotation direction control means 44 rotates the motor 13 in the reverse rotation direction, and the motor rotation speed control means 45 controls the descending speed of the ram 6. However, increase the rotation speed so that it becomes even faster. The curve Hb in FIG. 8 (B) shows the speed curve of the ram 6 in this case. Like this, Ram 6
Can be lowered at a higher speed, so that higher quality drilling can be performed. In this case, the restrictions on the plate thickness and the hole diameter become stricter, but if it is within the allowable range, high-quality machining one rank higher can be performed.

[0030]

Since the link type punch press of the present invention employs the link mechanism having the crank member, the swinging link, the connecting rod, and the restraining link, even if a motor having a relatively small output is used, a high press load is applied. It is possible to improve processing and processing cycle time.
Further, since the processing type selection means and the motor rotation direction control means for switching the forward / reverse rotation direction of the motor according to the processing type selected by the processing type selection means are provided, highly efficient processing is performed according to the required processing quality. And, high quality processing can be selectively used. In addition, when a drive transmission system that transmits the rotational drive of the motor to the crankshaft of the link mechanism so as to controllably move up and down the ram by controlling the rotation of the motor is used, that is, to give inertia to the flywheel, etc. When a drive transmission system without the intervening parts is used, the link mechanism is adopted and the controllability is excellent. When a servomotor is used as the above-mentioned motor, various advantages can be achieved by free speed control while taking advantage of the link press. In the state where the motor rotation direction control means sets the motor rotation direction in which the descending speed of the ram is faster than the ascending speed,
When the motor rotation speed control means for increasing the motor rotation speed is provided so that the descending speed of the ram is further increased, higher quality drilling can be performed.

[Brief description of drawings]

FIG. 1 is an explanatory view in which a broken front view of a link mechanism in a link type punch press according to an embodiment of the present invention and a block diagram showing a conceptual configuration of a control system are combined.

FIG. 2 is a cutaway side view of the link mechanism.

3A and 3B are respectively a front view and a side view of the link mechanism.

FIG. 4 is a side view showing a connected state of the link mechanism and the motor.

FIG. 5 is a perspective view showing a portion where the link mechanism and the motor are installed in a main body frame.

FIG. 6 is a perspective view of the link mechanism.

FIG. 7 is an explanatory diagram of an operation model of the link mechanism.

8A and 8B are graphs showing a relationship between a crank angle and a ram displacement at the time of normal rotation and reverse rotation of the motor in the same link mechanism.

FIG. 9 is a graph comparing ram displacement processes of the link mechanism and the crank type press.

FIG. 10 is a plan view showing the entire link type punch press of the embodiment.

FIG. 11 is a side view showing the entire link type punch press.

[Explanation of symbols]

1 ... Link mechanism 2 ... Crank member 3 ... crankshaft 4 ... Eccentric shaft 5 ... Swing link 6 ... Ram 7 ... Connecting rod 8 ... Restraint link 9 ... Frame 10 ... Guide member 11 ... pin 12 ... fulcrum axis 13 ... Motor 14 ... Drive transmission system 15 ... reducer 42 ... Processing type selection means 43 ... Ram axis control means 44 ... Motor rotation direction control means

Claims (3)

[Claims] 1. A motor, a link mechanism for converting a rotary motion transmitted from the motor via a drive transmission system into a linear motion, and a link mechanism installed below the link mechanism for press working by the linear motion. The link mechanism includes a ram that moves up and down, and a crank member having a crank shaft and an eccentric shaft portion, and first to third connecting portions that rotatably connect the crank member and the crank member. A swing link having a first connecting portion connected to the eccentric shaft portion of the crank member; a connecting rod having both ends connected to the second connecting portion and the upper end of the ram; and a base end having a frame. And a restraining link for pivotally controlling the swing of the swing link, the tip of which is rotatably connected to the third link portion of the swing link and which selects a type relating to the quality of the drilling process. type -Option means and, link type punch press with a rotating direction of the motor control means for switching the rotation direction of the forward and reverse of the motor according to the selected machining type of machining type selection means. 2. The drive transmission system is for transmitting the rotational drive of the motor to the crankshaft so that the raising / lowering operation of the ram can be controlled by controlling the rotation of the motor, and the motor is a servomotor. Link type punch press described in. 3. A motor rotation for increasing the rotation speed of the ram in such a manner that the descending speed of the ram is faster than the ascending speed by the motor rotating direction control means so that the descending speed of the ram becomes faster. The link type punch press according to claim 2, further comprising a speed control means.