Kabushiki Kaisha Yamada Dobby

Yamada Dobby Co., Ltd.

K.k. Yamada Dobby

Akihiro Yoshida

Yoichi Uno

Ryuichi Hattori

A press machine is configured with an adjustable slide stroke length. The press machine comprises a frame, a crankshaft borne rotatably on the frame, a slide disposed under the crankshaft, a first lever swingably supported on the frame, a second lever swingably connected to the first lever through a first pin, a displacing mechanism for displacing the first pin, and a linear approximation mechanism that exerts a horizontal force to the first pin so as to convert a rotation of each eccentric portion of the crankshaft into an elevating motion of the slide.

Press machine

A press machine includes upper and lower slides respectivelly attached to upper and lower portions of posts movable in the up and down directions; a link mechanism having first and second levers connected with each other to cause bending and stretching motion, one lever having a first fulcrum connected with a frame, and the other lever having a second fulcrum connected with the lower slide, a connecting mechanism for connecting a crankshaft with the link mechanism such that the first and second levers are bent and stretched as the crankshaft is rotated; and an adjusting device for connecting with the link mechanism or the connecting mechanism such that the range of the bent angle made by the first and second levers can be adjusted.

A press machine comprises a frame, a first crankshaft rotatively arranged on the frame, a second crankshaft arranged on the frame so as to rotate angularly, a pair of levers connected with each other such that they can make a bending and stretching motion, one lever being connected with the frame such that it can make a pivotal motion but can not be relatively displaced, the other lever being pivotally connected with the second crankshaft, and a link which connects the levers with the first crankshaft and bends and stretches both of the levers as the first crankshaft is rotated, thereby enabling to reduce the number of parts constituting a transmission mechanism for transmitting the rotary motion of the first crankshaft to a slide.

A press machine includes a frame, a first crankshaft rotated by a driving source, a second crankshaft connected with a slide, and a connection mechanism provided with a pair of levers connected with each other so as to carry out their bending-stretching motion as the first crankshaft is rotated. One lever has a first pivot and is connected, through the first pivot, with a position adjusting device for adjusting the position of the first pivot in the vertical or horizontal direction. The other lever has a second pivot and is connected, through the second pivot, with the eccentric shaft portion of the second crankshaft. The slide is connected with other eccentric shaft portion of the second crankshaft.

In order to eliminate noise generated from a clutch disk at racing state of a press, a clutch disk (29) arranged between a flywheel (27) and a working cylinder (40) is provided with a lining applying part (30) of annular shape and a projection (31) mounted on the flywheel (27). On inner circumferential surface of the projection (31), an inner groove part (311) is formed throughout the whole circumference from the inner circumferential edge to the outer circumferential edge in the circumferential direction, and on outer circumferential surface of the projection (31), an outer groove part (312) is formed throughout the whole circumference in the circumferential direction. Thereby the clutch disk (29) has flexibility in the axial direction, and if the lining applying part (30) is pushed by the working cylinder (40), the clutch disk (29) pushes a clutch rotary plate (34) by deflection of the projection (31) in the axial direction and rotates a crank shaft (25).

Clutch/brake device in press for little noise

A pressing machine includes a first connection device rotatably carried on an eccentric portion of a crankshaft, a second connection means for connecting the first connection device to a moving member, and a restriction device for restricting the moving direction of the second connection device to a reciprocating direction of the moving member. The second connection device includes one or more eccentric shafts each provided with a main shaft portion and an eccentric shaft portion each of which has an axis extending in the axial direction of the crankshaft, each of the eccentric shafts being rotatably connected at the main shaft portion thereof to the moving member and also rotatably connected at the eccentric shaft portion thereof to the first connection device.

Pressing machine with reciprocating slide

A pressing machine is characterized by including a plurality of crankshafts supported by a frame such that their axes of rotation extend in parallel, a yoke which connects the crankshafts so as to transmit the rotating motion of at least one crankshaft to another crankshaft, and a plurality of connecting rods connected at one end portions thereof to eccentric portions of the crankshafts and connected at the opposite ends thereof to a moving body which is mounted on the frame so as to reciprocate.

Pressing machine

A power transmission device for a press machine comprises a connection link connected to a crankshaft of the press machine and reciprocated in accordance with the rotation of the crankshaft, a first slider provided in a frame of the press machine so as to be reciprocated in a first direction, and pivotally connected to the connection link, a first link mechanism provided with a pair of first links pivotally connected to each other, wherein one of the first links is pivotally connected to either the connection link or the first slider so as to be folded and extended while following up the reciprocating movement of the connection link, a second slider provided in the frame displaceably in the first direction and pivotally connected to the other first link, and a mechanism for adjusting the position of the second slider in the first direction, whereby the bottom dead center position and the stroke length of a slide can be adjusted by a common mechanism.

Power transmission device for press machine

A power transmission device of a press machine comprises a rotary shaft rotated around a first axis by the rotation of a flywheel and an arm mounted on the rotary shaft and pivotally connected to a first link. A second link is pivotally connected to the first link so as to be rotated around a second axis, eccentric from the first axis, by the rotation of the arm. A lever is pivotally connected to the second link so as to be rotated around the first axis by the rotation of the second link and is also connected to a crankshaft so as to rotate the crankshaft. A rotor and guide constrain the rotary motion of the second link relative to the second axis to movement along a hypothetical circle centered on the second axis. The second link is engaged with the rotor at an engagement portion moved along the hypothetical circle in accordance with the rotation of the second link, whereby a uniform rotary motion is converted into a non-uniform rotary motion without using any gear and without making rotation axes of input and output shafts eccentric from each other.

Disclosed herein is means for correcting the position of bottom dead center of a slide in a press having a frame, a crankshaft rotatably mounted on the frame, and a slide connected to the crankshaft and movable in a vertical plane, wherein the correlation between the rotational speed of the crankshaft and the bottom dead center position of the slide is determined in one-to-one correspondence. The means comprises a variable speed motor for rotating the crankshaft; a sensor for sensing the position of bottom dead center of the slide; and a control circuit for comparing the signal generated from the sensor which is representative of the bottom dead center position with a signal representative of a preset reference position of bottom dead center of the slide and controlling the speed of the motor to suit the speed representative of the reference position of bottom dead center of the slide.

Growing community of inventors

Gifu-ken, Japan

Akihiro Yoshida