JPH0750071Y2 - Screen press equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a screen press device.

[Conventional technology]

As a conventional screen press device, an upper push type device for moving an upper mold up and down is known. This type of screw press device has a frame with a bead formed at the lower end, a guide screw at the upper end, and a flywheel at the upper end, and a lead screw in which the middle portion is screwed with the guide screw. And a slide is attached to the lower end of the lead screw. The slide 50 has a cylindrical shape with a bottom as shown in FIG. 5, and has a seat 51 for press-contacting the bearing cradle 55 of the lead screw 54 so as to be rotatable relative to each other.
An annular bearing retainer 52 that covers the outer peripheral portion of the bearing cradle 55 is provided at the upper end portion, and an internal space 53 having the seat 51 is filled with lubricating oil 56. The bearing cradle 55 of the lead screw 54 is inserted into the internal space 53, and the thrust bearing 57 is interposed between the outer peripheral upper surface of the bearing cradle 55 and the inner peripheral lower surface of the bearing retainer 52. The slide 50 is arranged in the middle portion of the frame so as to be vertically movable and the vertical movement is guided, and an upper mold 59 is provided on the lower surface.

Further, elastic biasing means 58 for biasing the pressure contact between the seat 51 of the slide 50 and the bearing cradle 55 of the lead screw 54 is provided, and in the normal state, the upper surface of the thrust bearing 57 and the lower surface of the bearing retainer 52 are A gap δ is formed between them.
The elastic biasing means 58 includes a slide 50 and a lead screw.
It has a function of bearing the self-weight of 54, reducing the friction of the screw portion of the lead screw 54, and elastically urging the pressure contact between the bearing cradle 55 and the seat 51.

Then, when the press forward stroke for lowering the slide 50 is completed, the lead screw 54 is driven to rise, and the elastic biasing means 58 drives the slide 50 to move upward to restore the lead screw 54 and the slide 50. Let At that time, the release means (not shown) is operated, the slide 50 is slightly moved downward against the urging force of the elastic urging means 58, the lower surface of the bearing retainer 52 is pressed against the upper surface of the thrust bearing 57, and the lead is The sheet 51 of the slide 50 and the lead screw are allowed while allowing relative rotation between the screw 54 and the slide 50.
A gap is formed between the bearing support 55 of 54. As a result, part of the lubricating oil 56 filled in the internal space 53 becomes a sheet.
Seizing is prevented because it penetrates between the 51 and the bearing cradle 55 and lubricates the space where rotation and sliding occur.

[Problems to be solved by the device]

However, in such a conventional screw press machine, in the press forward stroke, a gap δ is formed between the upper surface of the thrust bearing 57 and the lower surface of the bearing retainer 52.
Since it is a structure that secures the thrust bearing 57, it is easy for rattling to occur in the thrust bearing 57, and especially when the ascending reversal that shifts from the press forward stroke to the return stroke, a large impact load is applied to the bearing cradle 55 and the thrust bearing 57 is damaged. May occur. Specifically, when the rising reversing speed of the slide 50 that follows the rising reversing speed of the lead screw 54 is slow, the thrust bearing 57 violently collides with the lower surface of the bearing retainer 52. If this phenomenon is attempted to be alleviated by increasing the capacity of the elastic biasing means 58, the friction of the threaded portion of the lead screw 54 will increase, and a large downward drive force of the slide 50 will be required during the press forward stroke. As a result, the size of the screen press machine is increased.

[Means for Solving the Problems] The present invention has been made in view of the above-described conventional technical problems, and has a structure in which a bed provided with a lower mold is formed at the lower end and the bed is formed at the upper end. A frame provided with a guide screw, a lead screw screwed to the guide screw and having a bearing pedestal at a lower end, and a non-rotatable, vertically movably arranged lower surface at an intermediate portion of the frame. An upper die is provided, and the bearing cradle of the lead screw has a seat in which the bearing is rotatably pressed relative to one another in an internal space filled with lubricating oil, and an annular bearing retainer that covers the outer peripheral portion of the bearing cradle. A slide, a resilient urging means for urging pressure contact between the seat and the bearing pedestal, and an intervening member between the bearing pedestal and the bearing retainer. An elastic body which constantly elastically presses the alling cradle downwardly and has a bending allowance in a pressure contact state between the seat and the bearing cradle and a thrust which allows relative rotation between the bearing retainer and the bearing cradle. A screw press device comprising: a bearing; and a releasing means for moving the slide relative to the lead screw to release the pressure contact between the bearing holder and the seat.

[Action]

First, in the press forward stroke of the screw press device, the slide is in the relative raised position by the action of the elastic biasing means, and the seat of the slide presses against the lower surface of the bearing pedestal of the lead screw. The elastic body has a bending margin. In this state, if the lead screw is driven in the normal rotation and the lead screw that is screwed into the guide screw is given a downward linear motion, the slide can be performed while rotating and sliding between the bearing cradle and the seat. Perform the press process. Thereby, work such as forging, crushing, and bending is performed on the material between the upper mold and the lower mold.

When the upper die reaches the lower end position, the lead screw is driven to rotate in the reverse direction, and the lead screw is reversed from the downward linear movement to give the upward linear movement. At that moment, the bearing pedestal of the lead screw is rapidly moved up and returned due to the rapid reverse rotation drive, and when the return operation of the slide is delayed, the slide tends to rattle. However, between the bearing cradle and the bearing retainer, the bearing cradle is always elastically pressed downward with respect to the bearing retainer, and an elastic body having a bending allowance in a pressure contact state between the seat and the bearing retainer. Further, since the thrust bearing that allows the relative rotation between the bearing retainer and the bearing cradle is interposed, the elastic bearing of the elastic body is received, and the rattling of the thrust bearing is suppressed well.

When the lead screw rises and returns, the releasing means is actuated to relatively lower the slide against the rise returning force of the elastic biasing means and the elastic repulsive force of the elastic body, and the seat and the bearing. The pressure contact with the pedestal is released, a gap is formed between the two, and lubricating oil is supplied. At that time, since the elastic body having the bending allowance is compressed and the thrust bearing is pinched between the bearing retainer and the bearing retainer, the relative rotation between the bearing retainer and the bearing retainer causes the thrust bearing to move to the thrust bearing. Therefore, it is allowed smoothly.

By the above operation, the press forward stroke and the press return stroke are repeated.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show one embodiment of the screen press device. In the figure, reference numeral 1 indicates a frame-shaped frame, a bed 1a is formed at the lower end of the frame 1, and a guide screw 3 is fixed at the upper end. The lead screw 4 is screwed into the guide screw 3. The lead screen 4 has a flywheel 5 at the upper end,
A steel disk-shaped bearing support 6 is fixed to the lower end. If the flywheel 5 is brought into contact with one of the friction wheels 16 that are rotationally driven to frictionally drive the flywheel 5 and the lead screw 4 to rotate forward, the lead screw 4 that is screwed into the guide screw 3 will be formed. When the flywheel 5 is brought into contact with the other friction wheel 17 to drive frictionally and the flywheel 5 and the lead screw 4 are driven in reverse rotation, the lead screw 4 can be rotated in reverse. It is possible to give a rising linear motion with rotation to.

At the lower end of such a lead screen 4, slide 2
Is provided. The slide 2 has a copper sheet 2b fixed to the bottom of a bottomed cylindrical slide body 2a, and the lower surface of a bearing cradle 6 fixed to the lead screw 4 is rotated relative to the upper surface of the sheet 2b. Press freely. An annular bearing retainer 7 is fixed to the upper end opening of the slide 2 so as to form an inward flange shape, and the inner peripheral portion of the bearing retainer 7 covers the upper portion of the outer peripheral portion of the bearing cradle 6. is there. The internal space 2c of the slide body 2a is appropriately filled with lubricating oil 9. Such a slide 2 is installed in the middle portion of the frame 1 so as to be vertically movable and non-rotatable, and is guided for vertical movement.

A thrust bearing 8 that allows relative rotation between the lead screw 4 and the slide 2 is provided between the outer peripheral upper surface of the bearing cradle 6 of the lead screw 4 and the inner peripheral lower surface of the bearing retainer 7 of the slide 2. A space δ is interposed between the lower surface of the bearing retainer 7 and the upper surface of the thrust bearing 8 in the pressure contact state between the bearing cradle 6 and the seat 2b, as shown in FIG. As shown in FIG. 4, the thrust bearing 8 has a structure in which a ball 8d is rotatably held by a cage 8c between one race 8a positioned on the lower side and the other race 8b positioned on the upper side. One race 8a is fixed to the upper surface of the bearing pedestal 6. The ball 8d can be replaced with a roller.

Further, between the bed 1a of the frame 1 and the lower surface of the slide 2, a plurality of elastic biasing means for biasing the pressure contact between the seat 2b of the slide 2 and the bearing cradle 6 of the lead screw 4 are provided. A balance cylinder device 10 is arranged. In each balance cylinder device 10, a cylinder 10a is fixed to the bed 1a, a piston rod 10b is connected to the lower end of the slide 2, and each cylinder 10a is connected by a pipe 14 to an accumulator 15 that operates by gas or liquid. Has been done. Therefore, the accumulator 1 is always installed in each cylinder 10a.
The internal pressure of 5 acts to urge the piston rod 10b to project upward, and in the normal state, almost bears the own weight of the slide 2 and the lead screw 4, and the seat 2b and the bearing support 6
The pressure contact between the guide screw 3 and the lead screw 4 is reduced. In addition,
The balance cylinder device 10 may be arranged between the upper end of the frame 1 and the slide 2 to elastically pull up the slide 2. An upper die 11 is fixed to the center of the lower surface of the slide 2 and a lower die 12 is fixed to the center of the upper surface of the bed 1a so that the two dies 11 and 12 face each other.

Further, between the bearing retainer 7 of the slide 2 and the lower end of the flywheel 5, a plurality of cylinder devices 18 (with a return spring) as releasing means are provided. Each cylinder device 18 has a function of pressing the slide 2 downward to temporarily release the pressure contact between the bearing cradle 6 of the lead screw 4 and the seat 2b of the slide 2, and the switching valve 19 is interposed. It is connected to the air source 20 by a pipe 21. When the switching valve 19 is set to the a position, air is discharged to the atmosphere, the cylinder device 18 makes a return stroke by the action of the built-in return spring, and when the switching valve 19 is set to the b position. Compressed air is supplied from the air source 20, and the cylinder device 18 makes a forward stroke against the action of the return spring, so that the slide 2 can be pressed downward and relatively lowered with respect to the lead screw 4.

Then, between the upper surface of the thrust bearing 8 and the bearing retainer 7 of the slide 2, the seat 2b and the bearing cradle 6 are provided.
In a pressure contact state with C, the coil spring 13, which is an elastic body having a predetermined bending allowance corresponding to the gap δ and constantly elastically pressing the thrust bearing 8 downward against the slide 2, is put into a compressed state. Intervene. Specifically, the coil spring 13 is formed in the recess 7a of the bearing retainer 7.
The upper portion is embedded in the upper end of the thrust bearing 8 and is disposed between the upper surface of the other race 8b of the thrust bearing 8 and the bearing retainer 7, and a plurality of them are disposed at equal intervals in the circumferential direction of the lead screw 4. There is. The coil spring 13 can be replaced with a disc spring.

Next, the operation will be described.

First, in the forward stroke of the screen press device, as shown in FIG. 1, the switching valve 19 is set to the position a, and the stroke is returned by the action of the return spring incorporating the cylinder device 18. The internal pressure of the accumulator 15 acts on each balance cylinder device 10 and is in a relative raised position, and the upper surface of the seat 2b is in pressure contact with the lower surface of the bearing pedestal 6. In this state, one of the friction wheels 16 that is rotationally driven is brought into contact with the flywheel 5 and frictionally driven, whereby the lead screw 4 and the flywheel 5 are positively rotationally driven and screwed to the guide screw 3. The descending linear motion is given to the lead screw 4 which performs. Then, the slide 2 is guided by the frame 1 while performing the rotary sliding between the bearing support 6 and the seat 2b, and the press forward stroke is performed. As a result, the material between the upper die 11 and the lower die 12 is subjected to operations such as forging, crushing and bending.

After the upper die 11 reaches the lower end position, the other friction wheel 17 is brought into contact with the flywheel 5 as shown in FIG. 2, the lead screw 4 is driven in the reverse rotation, and the lead screw 4 descends linearly. It reverses from and gives rise linear motion. At that moment, when the flywheel 5 is rapidly driven to rotate in the reverse direction, the bearing cradle 6 of the lead screw 4 is rapidly raised and returned, and when the return operation of the slide 2 is delayed, the upper surface of the thrust bearing 8 and the bearing retainer 7 Due to the influence of the gap δ between and, the thrust bearing 8 tends to rattle. However, the coil spring 13 is compressed and interposed between the upper surface of the thrust bearing 8 and the bearing retainer 7 of the slide 2, and the thrust bearing 8
Since the slide bearing 2 is always elastically pressed downward, the backlash of the thrust bearing 8 is well suppressed.

Next, when the lead screw 4 is returned to the elevated position, as shown in FIG. 2, the switching valve 19 is set to the position b to supply the compressed air from the air source 20 to each cylinder device 18 and each balance cylinder device 10. The slide 2 is relatively moved downward against the ascending return force and the elastic repulsive force of the coil spring 13. As a result, the pressure contact between the seat 2b and the bearing cradle 6 of the lead screw 4 is released, and a gap is formed between the two 2b and 6, so that the lubricating oil 9 is applied to the rotary sliding surface between the two 2b and 6. Supplied. At that time, the coil spring 13
It is compressed and received in the recess 7a of the bearing retainer 7, and the upper surface (race 8b) of the thrust bearing 8 is pressed against the lower surface of the bearing retainer 7 of the slide 2. Therefore, the bearing cradle 6 of the lead screw 4 and the slide 2 The relative rotation between the bearing retainer 7 and
Therefore, it is allowed smoothly.

With such an operation, the press forward stroke and the press return stroke are repeated.

By the way, in the above embodiment, the thrust bearing 8 is fixed to the bearing pedestal 6 and
Coil spring 13 between the upper surface of and
Although the thrust bearing 8 is fixed to the bearing retainer 7 and the coil spring 13 is interposed between the lower surface of the thrust bearing 8 and the bearing cradle 6,
It is possible to obtain substantially the same action with respect to suppression of rattling of the thrust bearing 8.

[Effect of device]

As can be understood from the above description, according to the present invention, rattling of the thrust bearing that occurs at the moment when the lead screw is reversed from the descending linear motion to give the ascending linear motion is suppressed, so that the thrust bearing is suppressed. The members such as the bearing pedestal can be effectively prevented from being damaged, and the durability of the screen press device can be remarkably improved by the simple structure.

[Brief description of drawings]

1 to 4 show one embodiment of the present invention, FIG. 1 is a partial cross-sectional view of a screen press device, FIG. 2 is an explanatory view of operation, and FIG. 3 is a schematic view of the screen press device. FIG. 4 is an enlarged sectional view showing a thrust bearing, FIG. 4 is an enlarged sectional view showing a thrust bearing, and FIG. 1: Frame, 1a: Bed, 2: Slide, 2a: Slide body, 2
b: Seat, 3: Guide screen, 4: Lead screen, 5:
Flywheel, 6: bearing pedestal, 7: bearing retainer, 7
a: recess, 8: thrust bearing, 9: lubricating oil, 10: balance cylinder device (elastically urging means), 11: upper mold, 12: lower mold, 1
3: Coil spring (elastic body), 18: Cylinder device (release means), 15: Akymulator, 20: Air source.

Claims (1)

[Scope of utility model registration request] 1. A frame having a lower mold provided with a lower mold, a top end provided with a guide screw, and a lead screw having a bearing pedestal at the lower end screwed to the frame. , A lubricating oil is filled in a sheet in which the lead skeleton bearing pedestal is relatively rotatably press-fitted, the lower die is provided with an upper mold which is non-rotatably and vertically movable in the middle portion of the frame A slide having an annular bearing retainer for covering the outer peripheral portion of the bearing receiving base, an elastic biasing means for biasing the pressure contact between the seat and the bearing receiving base, and the bearing receiving base. It is interposed between the base and the bearing retainer, and always elastically presses the bearing retainer downward with respect to the bearing retainer, so that the seat and the bearing retainer are pressed against each other. An elastic body having a bending allowance, a thrust bearing that allows relative rotation between the bearing retainer and the bearing cradle, and the slide are relatively moved with respect to the lead screw to release pressure contact between the bearing cradle and the seat. And a canceling means for canceling.