JP4699284B2 - Drive mechanism in crank press - Google Patents

Description

  The present invention relates to a drive mechanism in a crank press. More specifically, the present invention relates to a drive mechanism in a crank press provided with a lifting cylinder for converting a rotational movement of a crankshaft into a vertical movement of a slide via a connecting rod and lifting the slide.

The basic structure of a conventional crank press will be described with reference to FIG. When the crankshaft 101 is rotated, the movement is transmitted to the slide 103 through the connecting rod 102, and the slide 103 is moved up and down, and the upper mold attached to the lower end thereof is lowered, thereby lowering the lower part on the bed 104. The material between the molds is pressed and molded.
The power for moving the slide 103 up and down is transmitted from the motor 110 to the flywheel 112 via the V belt 111, and the rotational energy of the flywheel 112 is transmitted to the crankshaft 101 via the main gear 114 meshed with the pinion 113. Reportedly.

In the above gear train structure, the main gear 114 is fixed to the crankshaft 101, and the flywheel 112 is also connected to the crankshaft 101 through the gear train, so that the weight of the drive system is considerably heavy (non- Patent Document 1).
Therefore, if the slide 103 is to be urged upward using the lifting cylinder, the lifting force of the lifting cylinder 103 must be increased, and thus a large lifting cylinder must be used. This causes an increase in the size and weight of the press and increases the manufacturing cost.

"Revised press machine" 56, 66 pages October 1st, 2001 2nd edition issued by Japan Machinist Co., Ltd.

  In view of the above circumstances, an object of the present invention is to provide a drive mechanism in a crank press in which a small lifting cylinder can be used and the press structure becomes compact.

The drive mechanism in the crank press of the first invention is a drive mechanism in a crank press provided with a lifting cylinder for converting the rotational movement of the crankshaft to the vertical movement of the slide via the connecting rod and lifting the slide, An input gear attached to one end of the crankshaft, a casing fixed to a press frame, a flywheel rotated by a motor, a drive shaft that rotates by receiving the rotational torque of the flywheel, The flywheel, the drive shaft, and the reducer are rotatably supported by the casing. The reducer is connected to an output end and a coupling that connects an output portion of the reducer to the input gear. and, wherein the reduction gear is a planetary reduction gear, the sun gear is provided at the output end of the drive shaft, the internal teeth There is provided on the inner periphery of the casing, and the planetary gear as an output unit, characterized in that it is connected to the coupling.
The drive mechanism in the crank press of the second invention is characterized in that, in the first invention, the input gear is frictionally fastened to one end of the crankshaft.
A drive mechanism in a crank press according to a third aspect of the invention is characterized in that, in the first aspect, a clutch is interposed between the flywheel and the input end of the drive shaft.
According to a fourth aspect of the present invention, there is provided a drive mechanism for a crank press according to the first aspect, wherein the lifting cylinder is a hydraulic cylinder, and a hydraulic circuit of the hydraulic cylinder supplies a high-pressure oil passage for supplying high-pressure oil and low-pressure oil for supplying low-pressure oil. And a control circuit that selects one of the high-pressure oil passage and the low-pressure oil passage.

According to the first invention, the flywheel, the drive shaft and the speed reducer are supported by the press frame via the casing, and their weight is not applied to the crankshaft. For this reason, the lifting force of the lifting cylinder may be small, and the lifting cylinder can be made small. Further, since using the Yu star gear reducer, in addition to the reduction gear itself is compact, since a large reduction ratio by the output unit of a planetary gear is obtained, made compact also from this point. Furthermore , since the internal gear is provided on the inner periphery of the casing and the casing also serves as the internal gear structurally, it is also compact from this point. For this reason, the increase in weight due to the use of the reduction gear is small, and in addition to this, the input gear can be reduced in size, so that the weight of the crankshaft system can be greatly reduced.
According to the second aspect of the present invention, the periphery of the input gear can be made compact and lightweight by frictionally fastening the input gear.
According to the third invention, since the flywheel is supported by the casing, the clutch can be incorporated inside the casing, and the flywheel periphery can be made compact.
According to the fourth aspect of the invention, if the high pressure oil passage is selected, the lifting cylinder can produce a large output, and the heavy crankshaft and the slide can be lifted and the press operation can be performed without any gaps in the respective parts of the press, resulting in high product accuracy. can get. If the low pressure oil passage is selected, the lifting cylinder has a low output, so that an instantaneous slide rise does not occur even during the inching operation, and the inching operation becomes easy.

Next, an embodiment of the present invention will be described with reference to the drawings.
The drive mechanism that is a feature of the present invention can be applied to any type of press as long as it is a type of press that lifts a crankshaft-slide system with a lifting cylinder. An embodiment applied to a press will be described.
FIG. 3 is a sectional side view of a crank press to which the present invention is applied. 4 is a cross-sectional front view taken along line IV-IV of FIG. 3 in the crank press. 5 is a cross-sectional plan view taken along line VV of FIG. 4 in the crank press.

(Basic structure)
First, the basic structure of the crank press of this embodiment will be described.
3 to 5, the press frame includes a base 2, two side frames 3 rising from the left and right sides of the base 2, a connecting plate 4 that connects upper ends of the two side frames 3, and The tie rod 5 is comprised. The two side frames 3 are connected to the lower base 2 by tie rods. Instead of using two side frames, a press of a type in which four columns are erected and the upper end of the column is coupled to a crown may be used.
A lower die holder 6 is provided on the upper surface of the base 2, and the lower die holder 6 holds the lower die M1.
A slide hard plate 7 and an upper die holder 8 are attached to the lower surface of a slide 30 to be described later, and the upper die M2 is held by the upper die holder 8.

  Reference numeral 10 denotes a crankshaft, which includes a shaft portion 11 at both ends and a central eccentric portion 12. The shaft portions 11 at both ends are rotatably supported by bearings 13 fixed to the side frame 3. A slide 30 is connected to the eccentric portion 12 via a connecting rod 20. The slide 30 is a substantially U-shaped member as viewed from the side with the upright portion rising from the front and rear of the bottom portion, and sliders 31 are attached to the four corners thereof, and the slide guide on the side frame 3 side. It slides on 32 and moves up and down while maintaining straightness.

Four lifting cylinders 40 are provided for lifting the slide 30 upward. Each lifting cylinder 40 is composed of a hydraulic cylinder, the cylinder body 41 is connected to the column 3 side, and the piston rod 42 is connected to the slide 30 via a bracket 43.
The slide 30 is always lifted and biased upward by the lifting cylinder 40.

  Next, the connecting rod 20 and the periphery of the slide 30 will be described with reference to FIGS. FIG. 6 is an enlarged side view around the connecting rod. FIG. 7 is an enlarged sectional front view around the connecting rod.

The connecting rod 20 includes a large head 21 and a small head 24, and the small head 24 is a member having a shape of a lower half of a cylinder, and an upper surface thereof is integrally coupled to a lower end of the large head 21. It has a shape.
An eccentric sleeve 14 is extrapolated on the outer periphery of the eccentric portion 12 of the crankshaft 10, and the large head 21 of the connecting rod 20 is extrapolated on the outer periphery thereof.

  The large head 21 is divided into two parts, and consists of an upper half 22 and a lower half 23. The upper half 22 and the lower half 23 are connected by a tie rod 25. The upper half 22 has a narrow width and is about 1/2 to 1/3 of the eccentric portion 12, but the lower half 23 has a wide width and is almost the same width as the eccentric portion 12. The small head 24 is connected to the lower part of the lower half 23 by a bolt 26. The cylindrical surface of the small head 24 is a pressurizing surface that transmits a pressing force from the connecting rod 20 to the slide 30.

  The slide 30 has a cubic pressure receiving portion 31 at the lower end, and a semi-cylindrical recess 32 is formed on the upper center surface thereof. The inner surface of the recess 32 serves as a pressure receiving surface that transmits pressure to the small head 24 of the connecting rod 20. A bush 33 made of copper alloy or the like is provided on the inner surface of the recess 32 so as to reduce friction with the small head 24.

Upright portions 34 rise from two sides of the slide 30 on the front and rear sides of the pressure receiving portion 31, and upper ends thereof are firmly connected to each other by a tie rod 36 via a connecting plate 35. Therefore, as shown in FIG. 6, the slide 30 is substantially U-shaped in a side view. Note that a key 38 is inserted between the connecting plate 35 and the upper end portion of the upright portion 34 to restrict the fixed position.
As described above, since the connecting plate 35 and the tie rod 36 pass above the connecting rod 20, the slide 30 has a shape surrounding the connecting rod 20 from above and below.
A cavity serving as a window 37 is formed in the central portion of the upright portion 34, and a motor 17 with a speed reducer of a shut height adjusting device, which will be described later, penetrates freely in a vertically movable manner.

The eccentric sleeve 14 is a known sleeve having a slightly eccentric center with respect to the center 0 ₂ (see FIG. 8) of the eccentric portion 12 of the crankshaft 10. A gear 15 is formed on the outer periphery of the central portion of the eccentric sleeve 13, and a worm 16 is engaged with the gear 15. A motor 17 with a speed reducer that rotates the worm 16 is fixed to the outer peripheral surface of the connecting rod 20. Since the motor 17 with a speed reducer passes through the window 37 of the slide 30, it does not interfere with the slide 30 during the press operation.

  A connecting pin 27 is passed through the mating surface of the small head 24 and the lower half 23 of the large head 21 through the mating surface. Both ends of the connecting pin 27 are supported by a pair of left and right bearings 39 provided on the slide 30. However, this connecting pin 27 connects the connecting rod 20 and the slide 30 for the convenience of assembly and disassembly, and does not receive pressure during the press operation. Therefore, the dimension may be small, and a gap is formed on the entire circumference with the inner circumference of the bearing 39 so as not to receive a shearing force during the press operation.

Next, the pressing action of the press will be described with reference to FIG.
First, the crank shaft 10 has been rotated to a rotational center 0 about ₁ of the shaft portion 11, the rotation center 0 ₂ of the eccentric portion 12 is eccentric from the rotation center 0 ₁ of the shaft portion 11, the eccentric portion 12 is rotated around 0 Revolve around _one . For this reason, the connecting rod 20 extrapolated to the eccentric portion 12 moves so as to continuously change its position as indicated by reference numerals (1) → (2) → (3) → (4). That is, the state (1) is changed again from the state (2) in which the connecting rod 20 is rotated 90 ° clockwise to the state (3) rotated 180 ° and the state (4) rotated 260 °. Forging is performed by performing the displacement operation shown in (1) to (4).
The slide 30 moves up and down by repeatedly rotating the crankshaft while the slide 30 is constantly biased upward by the lifting cylinder 40 (see FIG. 1). The vertical stroke L in this case is twice the distance between the rotation centers 0 ₁ and 0 ₂ .

In the state (1) indicated by the solid line in FIG. 8, the connecting rod 20 and the slide 30 are in the bottom dead center. In this state, the upper and lower molds M1 and M2 (see FIG. 1) are in contact with each other, and a forging operation is performed. The applied pressure transmitted from the slide 30 to the connecting rod 20 is performed on the outer peripheral surface of the small head 24 and the inner peripheral surface of the pressure receiving portion 32, both of which have a large semi-cylindrical area, so that the surface pressure is low and deformed. Etc. will not occur.
Therefore, the small head 24 and the slide 30 of the connecting rod 20 can be reduced in size. Further, since it is not necessary to use a large-diameter wrist pin, the size can be reduced from this point.

(Drive mechanism)
Next, details of the drive mechanism, which is the first feature of the present invention, will be described with reference to FIGS.
The shaft portions 11 (only one side is shown in FIGS. 1 and 2) at both ends of the crankshaft 10 are supported by a bearing 13, but there is a slight gap C between the shaft portion 11 and the bearing 13. It is the role of the lifting cylinder 40 to reduce the occurrence of impact due to the gap C during pressurization.
An input gear 18 is attached to the one shaft portion 11, and the input gear 18 is frictionally fastened by a known shring disc 19 or the like. As described above, the frictional fastening facilitates the assembling work, and the axial length of the shaft portion 11 can be shortened.
In the drive mechanism of the present invention, only the input gear 18 is attached to the crankshaft 10, and the remaining members are supported by a press frame (for example, the side frame 3) as an attachment.

A casing 50 is attached to the side frame 3 on one side of the press according to this embodiment. The casing 50 includes a first casing 51 on the side frame 3 side and a second casing 52 on the front end side. The second casing 52 is formed with an annular boss 53 for supporting a flywheel.
A flywheel 62 is rotatably supported on the outer periphery of the annular boss 53 via a bearing 61. The flywheel 62 has a V belt or the like wound around a motor (not shown), is rotated by the motor, stores kinetic energy, and transmits power to a drive shaft 64 described later.

A bearing 63 is attached to the opening in the center of the casing 52, and the drive shaft 64 is rotatably supported by the bearing 63.
On the other hand, a plurality of stays 65 extend radially inward from the side surface of the flywheel 62, and a bearing 66 is attached to the inner end thereof. The drive shaft 64 is supported at both ends by the bearing 66 and the bearing 63, and the drive shaft 64 rotates while stably holding the shaft center.
Further, a clutch 67 is attached between the inner end of each stay 65 and the drive shaft 64 so that connection / disconnection of power from the flywheel 62 to the drive shaft 64 can be controlled.

A reduction gear 70 is attached to an output end of the drive shaft 64, that is, one end portion facing the shaft portion 11 of the crankshaft 10. The speed reducer 70 is a planetary gear speed reducer, and includes a central sun gear 71, a planetary gear 72, and an outer peripheral internal gear 73. The sun gear 71 is mounted concentrically with the output end of the drive shaft 64, a plurality of planetary gears 72 are disposed so as to revolve around the outer periphery, and an inner gear 73 is provided on the outermost periphery. The internal gear 73 is formed on the inner periphery of the first casing 51.
The planetary gear 72 is supported by a rotating plate 74, and the rotating plate 74 is rotatably supported by a bearing 75 on the innermost end portion of the drive shaft 64 or the casing.

  An output gear 76 is formed on the rotating plate 74. The output gear 76 is the same concentric / diameter gear as the input gear 18. A coupling 77 is fitted on the outer periphery of the output gear 76 and the input gear 18. For this reason, the rotational torque of the planetary gear 72 is transmitted to the input gear 18 via the coupling 77.

  When the flywheel 62 is rotated by the motor by the drive mechanism having the above configuration, the rotational torque is changed from the clutch 67 → the drive shaft 64 → the planetary gear 72 of the planetary gear reducer 70 → the rotating plate 74 → the output gear 76 → the coupling 77. → The crankshaft 10 is rotated through the input gear 18.

According to the embodiment, the three members of the flywheel 62, the drive shaft 64, and the planetary gear speed reducer 70 are supported by the side frame 3 via the casing 50, and their weight is not applied to the crankshaft 10. For this reason, the lifting force of the lifting cylinder 40 may be small, and the lifting cylinder 40 can be made small. Further, since the torque reduced using the planetary gear reducer 70 is transmitted by the teeth of the entire gear, the input gear 18 can be made small. Thus, since the lifting cylinder 40 and the input gear 18 can be reduced in size, the structure of the press can be made compact.
Further, since the planetary gear speed reducer 70 is used, in addition to the reduction gear itself being compact, a large reduction ratio can be obtained by using the planetary gear 72 as an output unit. Furthermore, since the internal gear 73 is formed on the inner periphery of the first casing 51 and the casing also serves as the internal gear 73 structurally, it is also compact from this point.
For this reason, the increase in weight due to the use of the planetary gear speed reducer 70 is small, and in addition to this, the input gear 18 can be reduced in size, so that the weight of the crankshaft system can be greatly reduced.

Further, by frictionally fastening the input gear 18, the periphery of the input gear 18 can be made compact and lightweight.
Furthermore, since the flywheel 62 is supported by the casing 50, the clutch 67 can be incorporated inside the casing, and the flywheel 62 can be made compact.

(Hydraulic circuit of lifting cylinder 40)
Next, the hydraulic circuit of the lifting cylinder 40, which is the second feature of the present invention, will be described.
As described above, a hydraulic cylinder is used as the lifting cylinder 40 to secure a large output sufficient to lift the weight of the entire slide system and crankshaft system. A phenomenon occurs in which the slide 30 is pushed up at the moment when it is released, and the inching operability is deteriorated. For this reason, the hydraulic circuit is configured so as to lower the lifting pressure during normal inching operation.

The hydraulic circuit will be described with reference to FIG. FIG. 9 shows a circuit for one lifting cylinder 40. Since the same hydraulic circuit is provided for each of the four lifting cylinders 40, the following description will be made by taking the illustrated hydraulic circuit as a representative. Reference numeral 44 denotes a hydraulic pressure source such as an oil pump. The hydraulic pressure source 44 is connected to two oil paths, a high-pressure oil path 45 and a low-pressure oil path 46, in parallel. The oil supply passages 47 are connected to the piston side oil chamber of the lifting cylinder 40.
When high-pressure oil or low-pressure oil is supplied to the lifting cylinder 40 through these oil passages, the lifting cylinder 40 can perform a lifting operation at a high output or a low output.

Logic valves 48 and 49 are interposed in the high-pressure oil passage 45 and the low-pressure oil passage 46, respectively. The logic valves 48 and 49 are control valves for selecting and using any one of the oil passages 45 and 46. The low-pressure oil passage 46 is provided with a pressure control valve 81 set to a low pressure so as to reduce the pressure of hydraulic oil supplied through the low-pressure oil passage.
A pilot control valve 82 is an electromagnetically operated two-position directional control valve. Reference numeral 83 denotes a pilot pressure take-out passage, which takes out the pilot pressure from the hydraulic pressure source 44 and supplies it to the pilot control valve 82. Reference numerals 84 and 85 denote pilot pressure supply paths, which are connected from the pilot control valve 82 to the two logic valves 48 and 49, respectively.
In addition, 86 is a drain circuit, 87 is a counter balance accumulator, and 88 is a relief valve.

  In the above hydraulic circuit, when the pilot control valve 82 is switched to the I position shown in the figure, the pilot pressure is applied to the low pressure side logic valve 49 and the high pressure side logic valve 48 loses the pilot pressure. The side logic valve 49 is closed and the low-pressure oil passage 46 is shut off, and the high-pressure side logic valve 48 is opened and the high-pressure oil passage 45 is in communication. Therefore, since the high-pressure oil discharged from the hydraulic source 44 is supplied to the lifting cylinder 40 as it is, the lifting cylinder 40 can exhibit a large output. Therefore, it may be used in this state during a normal press operation.

Next, when performing an inching operation, the pilot control valve 82 is switched to the II position. In this case, the pilot pressure is applied to the logic valve 48 on the high pressure side, and the pilot pressure is lost on the logic valve 49 on the low pressure side, so the high pressure oil passage 45 is shut off and the low pressure oil passage 46 is in communication.
In this state, the hydraulic oil discharged from the hydraulic source 44 is depressurized by the relief valve 88, maintained at a low pressure by the pressure control valve 81, and then supplied to the lifting cylinder 40 via the supply oil passage 47. .
For this reason, since the lifting force of the lifting cylinder 40 is reduced, the phenomenon that the slide 30 is momentarily raised during the inching operation does not occur, and the slide 30 can be finely moved as the operator desires, so the inching operability is very good. Become.

(Other embodiments of the present invention)
The drive mechanism of the present invention is not limited to the above-described embodiment, but can also be applied to a press in which the crankshaft-slide system uses a conventional type crankshaft and connecting rod.
In short, the drive mechanism of the present invention can be applied to a press having any structure as long as the crankshaft-slide system is lifted by a lifting cylinder.

It is a front view of the drive mechanism in the crank press concerning one embodiment of the present invention. It is a top view of the drive mechanism. 1 is a cross-sectional side view of a crank press to which the present invention is applied. It is the IV-IV sectional view taken on the line of FIG. 3 in the crank press. It is the VV sectional view taken on the line of FIG. 4 in the crank press. It is an enlarged side view around a connecting rod. It is an expanded sectional front view around a connecting rod. It is operation | movement explanatory drawing of the crank press of this invention. It is a hydraulic circuit of a lifting cylinder. It is a general view of a conventional crank press and an explanatory view of a drive mechanism.

DESCRIPTION OF SYMBOLS 10 Crankshaft 18 Input gear 20 Connecting rod 30 Slide 40 Lifting cylinder 45 High pressure oil path 46 Low pressure oil path 50 Casing 62 Flywheel 64 Drive shaft 70 Planetary gear reducer 77 Coupling 81 Pressure control valve 82 Pilot control valve 88 Relief valve

Claims (4)

A drive mechanism in a crank press provided with a lifting cylinder for converting the rotational movement of the crankshaft to a vertical movement of the slide via a connecting rod and lifting the slide;
An input gear attached to one end of the crankshaft, a casing fixed to a press frame, a flywheel rotated by a motor, a drive shaft that rotates by receiving the rotational torque of the flywheel, A reduction gear connected to the output end, and a coupling for connecting the output portion of the reduction gear to the input gear,
The flywheel, the drive shaft and the speed reducer are rotatably supported by the casing ,
The speed reducer is a planetary gear speed reducer, a sun gear is provided at the output end of the drive shaft, an internal gear is provided at the inner periphery of the casing, and the planetary gear serves as an output portion and is connected to the coupling. drive mechanism in a crank press, wherein the <br/> being. The drive mechanism for a crank press according to claim 1, wherein the input gear is frictionally fastened to one end of the crankshaft. The drive mechanism in the crank press according to claim 1, wherein a clutch is interposed between the flywheel and an input end of the drive shaft. The lifting cylinder is a hydraulic cylinder;
The hydraulic circuit of the hydraulic cylinder includes a high pressure oil passage for supplying high pressure oil, a low pressure oil passage for supplying low pressure oil, and a control circuit for selecting one of the high pressure oil passage and the low pressure oil passage. The drive mechanism in the crank press according to claim 1.

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