JPH0775800B2 - Overload safety device for knuckle press machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for protecting press machine parts when the knuckle press machine is overloaded.

[0002]

BACKGROUND ART A knuckle press machine has a lower end of a first link whose upper end is connected to an eccentric part of a rotating member which is rotatable about a horizontal axis, and a second end whose lower end is connected to a vertically movable slide. The upper end of the link is connected, and the other end of the third link whose one end is connected to the eccentric part of the rotating member is connected to this connecting part,
By the reciprocating movement of the third link due to the rotation of the rotating member,
The second link is bent and the slide is moved up and down to press the material. Also, when the bottom dead center position of the slide is changed for die replacement, By rotating the moving member, the height position of the eccentric portion of the rotating member is changed, whereby the height positions of the first and second links are changed to adjust the bottom dead center position of the slide. There is.

[0003]

The press machine has, for example, 2
When a sheet of material is stacked and supplied, when the material is processed by lowering the slide, a large upward load that is a reaction force from the material acts on the press machine parts such as the slide, and this load is excessive. The load will damage the press machine parts. For this reason, press machines require measures against this overload, but in the past, knuckle press machines have detected the occurrence of overload with a load cell,
As a result, the operation of the press machine is urgently stopped, and there is generally no hydraulic overload safety device. Further, some medium-sized and large-sized press machines are provided with a hydraulic type or shear plate type overload safety device inside the slide, but there is a problem that the entire device becomes large.

An object of the present invention is to provide a hydraulic overload safety device which can be effectively installed in a knuckle press machine while reducing the size of the device.

[0005]

According to a first aspect of the present invention, there is provided a first eccentric portion of a rotating member which is rotatable about a horizontal axis.
The upper end of the link is connected, the lower end of the second link is connected to the vertically movable slide, and the one end is connected to the eccentric part of the rotating member by connecting the lower end of the first link and the upper end of the second link. In the knuckle press machine for connecting the other end of the formed third link and vertically moving the slide by bending the first and second links by the reciprocating movement of the third link by the rotation of the rotating member, A piston rod of a hydraulic cylinder extending in the tangential direction of the rotating member is engaged with the hydraulic cylinder, and a hydraulic chamber accommodating the piston of the piston rod is provided, and the hydraulic cylinder is provided with a pressure chamber connected to the hydraulic chamber. An oil supply passage and an oil escape passage are provided on both sides of the hydraulic chamber in the piston movement direction, and the piston is brought into contact with the end wall of the hydraulic chamber on the side of the oil escape passage by the pressure of the pressure oil supplied from the pressure oil supply passage to the hydraulic chamber. sticker With the ability and is characterized in that to enable communication between the hydraulic chamber and an oil relief passage by the movement of the pressure oil supply passage side of the piston due to an overload.

A second invention of the present invention is the same as the first invention,
The rotating member is a worm wheel, the piston rod is a worm gear shaft having a worm gear that meshes with the worm wheel, and a drive motor for a slide adjusting device that adjusts the bottom dead center position of the slide is connected to the worm gear shaft. It is characterized by having done.

A third invention of the present invention is the first invention or the second invention.
In the invention, a hydraulic pressure generator for supplying pressure oil to the hydraulic chamber is connected to the pressure oil supply passage, and a hydraulic pressure setting device is connected to the hydraulic pressure generating device. It is characterized in that the pressure of the oil is changed in correspondence with the height position of the eccentric part of the rotating member to which the upper end of the first link is connected.

[0008]

In the first aspect of the invention, the piston normally contacts the end wall of the hydraulic chamber on the side of the oil escape passage due to the pressure of the pressure oil supplied to the hydraulic chamber. Therefore, the piston rod does not move. The rotating member also does not rotate, and in this state, the reciprocating motion of the third link due to the rotation of the rotating member causes the first and second links to perform a bending motion, and the slide moves up and down. If an overload occurs when the slide descends and the material is processed,
A large upward load is applied to the second link, and this load acts as a moment to rotate the rotating member, which causes the piston rod to resist the pressure of the pressure oil in the hydraulic chamber. Move to the side, this
The hydraulic chamber and the oil escape passage communicate with each other, the pressure oil in the hydraulic chamber escapes from the oil escape passage, and the first and second links and the like are in a freely movable state, so that the press machine component is protected from overload. .

In the second aspect of the invention, when the drive motor for the slide adjusting device is rotated, the worm wheel, which is the rotating member, rotates via the worm gear shaft, which is the piston rod, so that the eccentric portion of the worm wheel has an upper end. A first link connected to the first link, and a second link connected to the first link
Since the height position of the link changes, the bottom dead center position of the slide can be adjusted. Therefore, in the second aspect of the invention, the overload safety device and the slide adjusting device for adjusting the bottom dead center position of the slide can be configured by sharing some of the components.

In the third invention, when the rotating member is rotated to adjust the bottom dead center position of the slide, the height position of the eccentric portion of the rotating member connected to the upper end of the first link changes. As a result, even when the magnitude of the moment generated in the rotating member changes when an overload occurs, the pressure of the pressure oil supplied from the hydraulic pressure generator to the hydraulic chamber is adjusted by the hydraulic pressure setting device, so that the pressure is always maintained. It becomes possible to activate the overload safety device when an overload of a predetermined magnitude occurs.

[0011]

An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, a worm wheel 2 which is a rotating member is attached to the horizontal shaft 1, and the worm wheel 2 is rotatable around an axis O ₁ of the horizontal shaft 1. The worm wheel 2 is provided with an eccentric portion 3 such as a pin, and the eccentric portion 3 draws a circular locus A about the axis O ₁ by the rotation of the worm wheel 2. The eccentric part 3 has a first
An upper end 4A of the link 4 is connected, and a slide 5 is vertically movable by being guided by a guide member (not shown).
The lower end 6B of the second link 6 is connected to the, and the lower end 4B of the first link 4 and the upper end 6A of the second link 6 are connected to each other.

A large-diameter gear 8 that is a rotating member meshes with a small-diameter gear 7 that is rotated by a motor (not shown).
An eccentric portion 9 is provided by a pin or the like, and the rotation of the large diameter gear 8 causes the eccentric portion 9 to have an axis O of the central axis 10 of the large diameter gear 8.
Draw a circular locus B centered on ₂ . One end 11A of the third link 11 is connected to the eccentric part 9, and the other end 11B is a connecting part 1 of the lower end 4B of the first link 4 and the upper end 6A of the second link 6.
It is connected to 2.

The worm wheel 2 has a worm gear 13
Are engaged with each other, and the worm gear shaft including the worm gear 13 is provided with the piston 14, so that the worm gear shaft is the piston rod 15. This piston rod 15 extending in the tangential direction of the worm wheel 2 is axially slidably supported by a bearing 16, and the piston 14 is housed in a hydraulic chamber 18 of a hydraulic cylinder 17. The outer diameter of the piston 14 is slightly smaller than the inner diameter of the hydraulic chamber 18, so that a gap 19 is provided between them.

The hydraulic cylinder 17 is provided with a pressure oil supply passage 20 and an oil escape passage 21 which are connected to the hydraulic chamber 18, and these are provided on both sides of the hydraulic chamber 18 in the moving direction of the piston 14. When the piston 14 contacts the end wall 22 of the hydraulic chamber 18 on the oil escape passage 21 side, the contact between the piston 14 and the end wall 22 seals the connection between the hydraulic chamber 18 and the oil escape passage 21. It has become. A pressure oil supply circuit 23 is connected to the pressure oil supply passage 20, and the circuit 23 extends from an oil tank 25 via a hydraulic pressure generator 24 including a hydraulic pump, a regulator and the like. An oil escape circuit 26 is connected to the oil escape passage 21, and the circuit 26 extends to an oil tank 25.

The oil in the oil tank 25 is turned into pressure oil by the hydraulic pressure generator 24, and this pressure oil is supplied to the hydraulic chamber 18 via the pressure oil supply circuit 23 and the pressure oil supply passage 20. Hydraulic chamber 1
The piston 14 comes into contact with the end wall 22 of the hydraulic chamber 18 on the oil escape passage 21 side by the pressure of the hydraulic pressure supplied to the piston 8, and the piston 14 and further the piston rod 15 are pressurized with the hydraulic oil during normal operation of the press machine. Its position is maintained by the pressure of.

The above piston 14 and piston rod 1
5, the hydraulic cylinder 17 and the like constitute a hydraulic overload safety device 27.

The rear end of the piston rod 15 projects from the hydraulic cylinder 17, and a driven gear 28 is fixedly mounted on the rear end of the piston rod 15. A drive gear 30 fixed to the drive shaft of a motor 29 meshes with the driven gear 28, and the motor 29 rotates the piston rod 15 via these gears 28 and 30, and this rotation is performed via the worm gear 13. Worm wheel 2
To be transmitted to. When the worm wheel 2 rotates, the height position of the eccentric part 3 to which the upper end 4A of the first link 4 is connected changes, so that the overall height positions of the first and second links 4 and 6 are changed. Thus, the bottom dead center position of the slide 5 can be adjusted when changing the mold.

Therefore, the worm gear 13, the piston rod 15, the gears 28 and 30, the motor 29, etc. constitute a slide adjusting device 31 for adjusting the bottom dead center position of the slide 5.

A worm wheel rotation angle detection sensor 32 is arranged in the vicinity of the horizontal shaft 1 which is the rotation center axis of the worm wheel 2. The sensor 32 is a rotation angle of the worm wheel 2 by the slide adjusting device 31. In other words, it is for detecting the height position of the eccentric portion 3 of the worm wheel 2. The detection signal from the sensor 32 is sent to the slide adjustment amount (bottom dead center position adjustment amount of the slide 5) detection device 33, and this device 33 measures the height position of the eccentric portion 3 of the worm wheel 2. ing. The measurement result measured by the slide adjustment amount detecting device 33 is the hydraulic pressure setting device 3 connected to the hydraulic pressure generating device 24.
4 to the hydraulic pressure setting device 34.
To set the pressure of the pressure oil supplied from the hydraulic chamber 18 to the one corresponding to the height position of the eccentric portion 3 (see FIGS. 2 and 3 described later).

Next, the operation will be described. When the press machine is operated, as described above, the pressure of the pressure oil supplied to the hydraulic chamber 18 causes the piston 14 to come into contact with the end wall 22, so that the worm wheel 13 cannot rotate in the worm gear 13. The pressure oil that is retained and does not flow out into the oil escape passage 21 due to the abutment sealing action between the piston 14 and the end wall 22. When the large-diameter gear 8 that is a rotating member is rotated by the small-diameter gear 7, the third link 11 whose one end 11A is connected to the eccentric portion 9 of the gear 8
Reciprocates, whereby the first link 4 and the second link 6 bend at the connecting portion 12 of these links 4 and 6, and the slide 5 moves up and down by this bending movement and is attached to the slide 5. The material is pressed by the upper die 35 and the lower die 37 attached to the bolster 36.

When, for example, two materials are stacked and supplied to the press machine, a large upward load, which is a reaction force of the material processing load, is generated in the first and second links 4 and 6 during material processing, and this load is applied. Is a moment that attempts to rotate the worm wheel 2 to the right in FIG. 1 via the eccentric portion 3,
Therefore, a moving load to the right acts on the worm gear 13 and the piston rod 15. When this moving load becomes larger than the leftward load due to the pressure of the pressure oil in the hydraulic chamber 18 acting on the piston 14, the piston 14 and the piston rod 15 move rightward, and immediately after this movement begins, the piston 14 and Since the contact sealing action with the end wall 22 is released, the pressure oil in the hydraulic chamber 18 escapes to the oil escape passage 21 and is further returned to the oil tank 25 via the oil escape circuit 26. That is, the hydraulic overload safety device 27 has been actuated, and the pressure of the pressure oil in the hydraulic chamber 18 acting on the piston 14 disappears, so that the first and second links 4, 6 are released. , The worm wheel 2 and the like are allowed to move freely, and as a result, these press machine parts are protected from overload.

Upper mold 3 for producing different pressed products
5. When the die including the lower die 37 is exchanged and it becomes necessary to change the bottom dead center position of the slide 5, the motor 29 of the slide adjusting device 31 is driven, whereby the gear 30, 28, piston rod 15,
The worm wheel 2 is rotated through the worm gear 13 by a required angle. As a result, the height position of the eccentric portion 3 of the worm wheel 2 is changed, so that the overall height position of the first and second links 4 and 6 is changed, whereby the bottom dead center position of the slide 5 is changed. It

When the bottom dead center position of the slide 5 is changed by the slide adjusting device 31 as described above, the height position of the eccentric portion 3 of the worm wheel 2 changes, and as a result,
Shaft center O which is the center of rotation of eccentric part 3 and worm wheel 2
The horizontal distance to and from ₁ will change. According to this, when the overload occurs, the upward load acting on the first and second links 4 and 6 causes the worm wheel 2 to move.
The magnitude of the rotational moment in the middle right direction changes, and therefore, if the pressure oil of the same pressure is supplied to the hydraulic chamber 18, the magnitude of the overload at which the overload safety device 27 operates will be different. Will occur.

2 and 3 show means for solving such a problem. In FIG. 2, F is an upward load acting on the first and second links 4, 6 when an overload occurs, e is an eccentric amount of the eccentric portion 3 from the axis O ₁ , and θ is a horizontal direction of the eccentric portion 3. , D is the diameter of the pitch circle of the worm wheel 2 that meshes with the worm gear 13, M is the rotational moment of the worm wheel 2 caused by F, P is the moving load of the piston rod 15 caused by M, and S is the eccentric portion 3. Height position change amount (bottom dead center position adjustment amount of slide 5)
This S is distributed in equal amounts from the middle point at the horizontal position at the same height as the axis O ₁ to the upper limit and the lower limit.
When the press machine is overloaded, M and P are represented by the following mathematical expressions.

[0025]

[Equation 1] M = F · e · cos θ P = 2 · M / D = 2 · F · e · cos θ / D

In FIG. 3, when θ changes, in other words,
7 is a graph showing changes in M and P when the height position of the eccentric portion 3 changes. M and P become maximum when the eccentric portion 3 is at the midpoint, and M and P gradually decrease with a symmetrical curve as the position of the eccentric portion 3 changes from the midpoint to the upper limit direction and the lower limit direction.

When the bottom dead center position of the slide 5 is adjusted,
Since P acting on the piston rod 15 changes in this way due to the occurrence of overload, unless the pressure of the pressure oil supplied to the hydraulic chamber 18 is adjusted to a size corresponding to P, the overload safety device 27 has the same size. Can not be activated when overload occurs. In order to operate the overload safety device 27 by the occurrence of an overload of the same magnitude, the pressure of the pressure oil supplied to the hydraulic chamber 18 is set to a magnitude corresponding to P. Is performed by changing the oil pressure setting by the oil pressure setting device 34 connected to the oil pressure generating device 24, and the oil in the oil tank 25 is pressurized by the oil pressure generating device 24 to the pressure set by the oil pressure setting device 34. While being supplied to the hydraulic chamber 18. Hydraulic pressure setting device 34
The hydraulic pressure may be set manually by the operator, but in the present embodiment, the height position of the eccentric portion 3 of the worm wheel 2 is automatically detected by the sensor 32 and the slide adjustment amount detection device 33. Using this detection signal, the hydraulic pressure setting work by the hydraulic pressure setting device 34 can be performed automatically.

According to the present embodiment described above, the worm wheel 2 serving as a rotating member is engaged with the piston rod 15 extending in the tangential direction through the worm gear 13, whereby the first, second, and third worm wheels 13 are engaged. 3 Knuckle press machine using links 4, 6, 11 Hydraulic overload safety device 2
7 can be effectively provided, and P shown in FIG. 2 can be calculated from the ratio of the eccentric amount e of the eccentric portion 3 of the worm wheel 2 to the radius D / 2 of the pitch circle of the worm wheel 2.
Therefore, compared to the case where a hydraulic overload safety device is provided inside the slide and an upward load when an overload occurs is directly applied to this overload safety device, The pressure of the supplied pressure oil can be reduced, and as a result, the hydraulic cylinder 17 can be made compact and the overload safety device 27 can be made compact.

Further, since the piston rod 15 is a worm gear shaft having a worm gear 13 meshing with the worm wheel 2 and a motor 29 is connected to this worm gear shaft via gears 28 and 30, the worm wheel 2 is rotated by the motor 29. This makes it possible to change the height position of the eccentric portion 3 and adjust the bottom dead center position of the slide 5. Further, the slide adjusting device 31 for adjusting the position of the bottom dead center can be configured with the overload safety device 27, the piston rod 15 and the like as a common component, and the required number of components can be reduced.

Further, a hydraulic pressure setting device 34 is connected to a hydraulic pressure generating device 24 for supplying pressure oil to the hydraulic pressure chamber 18, and the hydraulic pressure setting device 34 corresponds to the height position of the eccentric portion 3 of the worm wheel 2. Since the pressure of the pressure oil supplied to 18 is changed, even if the bottom dead center position of the slide 5 is adjusted by the rotation of the worm wheel 2, when the overload safety device 27 is overloaded by the same amount. Will always be able to operate.

When a so-called stick phenomenon occurs during processing of the material by the press machine, for example, an opening / closing valve provided between the pressure oil supply circuit 23 and the oil relief circuit 26 is opened to release the pressure oil in the hydraulic chamber 18. This stick state can be released by letting it escape to the oil tank 25, and the overload safety device 27
Can also be used as a stick release device.

In the present embodiment described above, the sensor 32 and the slide adjustment amount detection device 33 automatically detect the height position of the eccentric portion 3 of the worm wheel 2, whereby the hydraulic pressure setting operation by the hydraulic pressure setting device 34 can be performed automatically. However, the hydraulic setting device 34 may be of a type manually operated by an operator.

In the above embodiment, the piston rod 15
Is a worm gear shaft provided with a worm gear 13,
This shaft is rotated by the motor 29 for the slide adjusting device to adjust the bottom dead center position of the slide 5. The bottom dead center position of the slide 5 is adjusted by the horizontal shaft which is the central axis of the worm wheel 2. 1 may be rotated by a motor. However, if it is configured as in the above-described embodiment, as described above, it is possible to reduce the number of parts by sharing the parts.

[0034]

According to the first aspect of the present invention, the knuckle press machine can be effectively provided with a hydraulic overload safety device, and the pressure of the pressure oil supplied to the hydraulic chamber can be reduced. An effect that the overload safety device can be downsized can be obtained.

According to the second aspect of the present invention, the rotating member is a worm wheel, and the worm gear has a worm wheel in which the piston rod that engages with the rotating member and extends in the tangential direction of the rotating member meshes with the worm wheel. A worm gear shaft was used, and this worm gear shaft was rotated by the motor for the slide adjustment device.Therefore, the slide adjustment device for adjusting the bottom dead center position of the slide was made common with some parts of the overload safety device. As a result, the number of parts can be reduced and the structure can be simplified.

Further, according to the third aspect of the present invention, a hydraulic pressure setting device is connected to a hydraulic pressure generating device for supplying pressure oil into the hydraulic pressure chamber of the overload safety device, and the hydraulic pressure setting device supplies the hydraulic pressure chamber with the hydraulic pressure. Since the pressure of the pressure oil can be changed in correspondence with the height position of the eccentric part of the rotating member to which the upper end of the first link is connected, the bottom dead center position of the slide is rotated by rotating the rotating member. Even if it is adjusted, the overload safety device can always be activated when the same amount of overload occurs, and the magnitude of the overload at which the overload safety device operates depends on the bottom dead center of the slide. It can be prevented from changing by changing the position.

[Brief description of drawings]

FIG. 1 is a schematic view showing an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing that a moving load acting on a piston rod changes by changing a bottom dead center position of a slide.

FIG. 3 is a graph showing that M and P shown in FIG. 2 vary depending on the height position of an eccentric portion of a worm wheel that is a rotating member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Horizontal shaft 2 Worm wheel which is a rotating member 3 Eccentric part 4 1st link 5 Slide 6 2nd link 8 Large diameter gear which is a rotating member 9 Eccentric part 11 3rd link 13 Worm gear 14 Piston 15 Piston rod which is a worm gear shaft 17 Hydraulic Cylinder 18 Hydraulic Chamber 20 Pressure Oil Supply Passage 21 Oil Relief Passage 24 Hydraulic Pressure Generator 27 Overload Safety Device 31 Slide Adjuster 34 Hydraulic Setter

Claims (2)

[Claims] 1. A rotating member capable of rotating around a horizontal axis (1).
First link whose upper end is connected to the eccentric part (3 ) of (2)
The lower end of (4) is connected to the upper end of the second link (6) whose lower end is connected to the vertically movable slide (5), and one end is connected to this connecting portion to the eccentric part (9 ) of the rotating member (8). ) to be connected to connect the other end of the third re <br/> link reciprocating by the rotation of the rotary member (8) (11), the third link (11)
First by reciprocating of the knuckle press machine for vertically moving said slide (5) by bending movement of the second link, the piston rod extending in the tangential direction of the rotating member to the rotating member (2) (2) (15) engaged with, accommodating a piston (14) of the piston rod (15) to the hydraulic cylinder (17) hydraulic chamber in (18), the hydraulic chamber in the hydraulic cylinder (17) and (18) the hydraulic chamber from said piston (14) provided in the moving direction on both sides, the pressure oil supply passage connected to pressure oil supply passage (20) and the oil relief passage (21) and said hydraulic chamber (18) (20) ( 18)
The pressure of the pressure oil supplied to the piston (14) enables the piston (14) to abut and seal against the end wall of the hydraulic chamber (18) on the oil escape passage (21) side, and the piston (14) due to overload. Of the oil to the pressure oil supply passage (20) allows the hydraulic chamber (18) and the oil escape passage (21) to communicate with each other, and the rotating member (2) is a worm wheel.
The worm wheel to the teeth of the piston rod.
Worm gear shaft with matching worm gear (13)
Yes, the bottom dead of the slide (5) on this worm gear shaft
The drive motor for the slide adjustment device that adjusts the point position is connected.
An overload safety device for knuckle press machines characterized by being continued . 2. The overload safety device for a knuckle press machine according to claim 1 , wherein a hydraulic pressure generator for supplying pressure oil to the hydraulic chamber (18) is provided in the pressure oil supply passage (20).
(24) is connected and this hydraulic pressure generator
An oil pressure setting device (34) for setting the pressure of the pressure oil supplied to the oil pressure chamber (18) corresponding to the height position of the eccentric portion (3) of the rotating member (2) is provided at (24). Overload safety device for knuckle press machine characterized by being connected. "