JP3227440B2 - Pressurizing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressing device such as a pressing device used for sheet metal processing, and more particularly to a fixed point processing requiring accurate position control and a small driving energy. And a pressure device.

[0002]

2. Description of the Related Art Conventionally, as a means for driving a ram in contact with a work in a press working apparatus, a hydraulic cylinder has been widely used, and a hydraulic cylinder has been widely used.
In the press apparatus driven by the hydraulic cylinder, when performing fixed-point processing, that is, processing in a state where the distance between the ram and the table is kept constant, it is necessary to perform processing that is generally called “pumping processing”.

[0003] FIG. 4 is an explanatory view showing a conventional boring process. In FIG. 4, reference numeral 31 denotes a table, and the ram 32 of the press device is moved up and down by, for example, a hydraulic cylinder with respect to the table 31 so as to press the work 33. In this case, in order to accurately machine the workpiece 33 to the thickness dimension t, the projecting portion 3 corresponding to the thickness dimension t is provided below the lower end of the ram 32 from the operating surface 34.
5 is protruded.

When the ram 32 is operated downward by the above-described structure, a predetermined processing can be performed on the work 33 by the operation surface 34. However, when the projection 35 of the ram 32 comes into contact with the table 31, the work 33 can be processed. , The thickness t of the workpiece 33 can be accurately secured, the processing can be performed with no variation in the dimensions, and the processing accuracy for the workpiece 33 can be improved.

[0005]

The machining mode shown in FIG. 4 has the following problems while the machining accuracy can be improved by fixed-point machining. That is, in addition to the ram 32 abutting against the workpiece 33, the protrusion 35 of the ram 32 also collides against the table 31. Thus, a collision sound is generated. In the case of high-speed machining with a large number of operations, there is a problem that the noise becomes intense and the working environment is impaired.

[0006] On the other hand, fixed-point machining using an electric press has also been used in the past, and is known to be advantageous in preventing generation of noise due to boring by the hydraulic press or the like.

FIG. 5 is a longitudinal sectional view of a main part showing an example of a conventional electric press, which is described, for example, in Japanese Patent Application Laid-Open No. 6-218591. In FIG. 5, reference numeral 41 denotes a pressing force generating means, which is housed in a head frame 44 provided on a column 43 formed integrally with a table 42.

Reference numeral 45 denotes a cylindrical main body, which is provided inside the head frame 44 and has a bearing 46 at the upper end. Reference numeral 47 denotes a screw shaft, the upper end of which is supported by a bearing portion 46, and is formed in a suspended state. Reference numeral 48 denotes a ram shaft, which is formed in a hollow cylindrical shape, and a nut body 49 screwed to the screw shaft 47 is fixed to an upper end thereof, and is provided in the cylindrical main body 45 so as to be vertically movable. . Reference numeral 50 denotes a pressing body, which is detachably provided at the lower end of the ram shaft 48. The screw shaft 47 and the nut body 49 are engaged with a ball screw.

Next, reference numeral 51 denotes a steady rest, and the head frame 44
And a connecting plate 54 provided at a lower end of the ram shaft 48 and the steadying rod 53. I have. Reference numeral 55 denotes a drive motor,
The screw shaft 47 is formed in a rotatable manner via a pulley 56 and a belt 57 provided at the upper end of the screw shaft 47.

The initial position of the pressing body 50, the fixed position stop point, the rotation speed of the drive motor 55, the forward / reverse rotation instruction, and the like can be performed by measuring means, a central processing unit, and the like, not shown.

With the above structure, the screw shaft 47 is driven by the drive motor 55 via the belt 57 and the pulley 56.
Is rotated, the ram shaft 48 with the nut body 49 fixed to the upper end thereof moves down, and the pressing body 50 comes into contact with the workpiece W at a preset position and pressing force as shown by a chain line, Processing is performed. After the machining, the ram shaft 48 and the pressing body 50 are raised by the reverse rotation of the drive motor 55,
Return to the initial position. By repeating the above operation, predetermined fixed-point processing can be sequentially performed on a plurality of workpieces W.

According to the above-described electric press, fixed point processing can be performed without generating noise. However, the conventional press has the following problems. That is, the height h of the lower end surface of the pressing body 50 from the table 42 in FIG. 5 is controlled to be always constant because the fixed point processing is performed, and the workpiece to be processed via the pressing body 50 at this position. A predetermined pressing force is applied to W.
In other words, a reaction force corresponding to the above-mentioned pressing force always acts on the screw shaft 47 and the nut body 49 at the same relative position.

On the other hand, the screw shaft 47 and the nut body 49 are engaged with a ball screw in order to accurately and accurately control the positions of the ram shaft 48 and the pressing body 50. The ball groove is engaged by line contact or point contact. For this reason, if the above-mentioned reaction force acts on the ball and the ball groove many times at the same relative position, the ball and / or the ball groove will be locally worn, thereby reducing the processing accuracy and shortening the life. There is a problem. The screw shaft 47 and the nut body 4
The above-mentioned problem exists even when 9 is normal screw engagement.

In the above-described electric press, the pressing force applied to the workpiece W is determined by the capacity of the drive motor 55. Therefore, in the case of a large-capacity press device, the drive motor 55 also has a large capacity. Is required. Further, in a large-capacity and large-sized press device, the movable body including the ram shaft 48 and the pressing body 50 is also large and heavy, so that the driving energy required for the vertical movement of the movable body repeatedly becomes large. There is a problem that it will spur large size and large capacity.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems existing in the above prior art and to provide a pressurizing apparatus for fixed point processing which has a high processing accuracy, a long life and a small driving energy. Things.

[0016]

In order to solve the above-mentioned problems, according to the present invention, there is provided a substrate, a support plate provided at a predetermined distance from the substrate, and A screw shaft rotatably supported in a forward and reverse direction, a brake device interposed on the screw shaft and selectively restraining rotation of the screw shaft, and a movable engagement movably engaged in parallel with the axis of the screw shaft. A nut member provided in the movable body and formed to screw with the screw shaft; a differential male screw provided on an outer periphery of the nut member or on the substrate; and formed in a hollow cylindrical shape. A differential member formed on the inner peripheral surface and having a female differential screw threadably engaged with the differential male screw and rotatably formed; and a differential gear fixed to the differential member and engaged with the first gear. End point of movement of the movable body. Moving the pressure body facing the movable body or the movable body by the rotation of the differential member while restraining rotation of the screw shaft in the near to a predetermined movement end point, it adopts the technical means of. Note that the first gear and the second gear are not limited to only two gears, and a properly known gear group that forms a reduction mechanism including three or more gears can be used.

In the present invention, the substrate and the support plate can be arranged in parallel with the horizontal plane, and the axis of the guide bar can be arranged in the vertical direction.

Next, in the above invention, the screw shaft and the nut member can be engaged with a ball screw. With such a configuration, the movement of the movable body becomes smooth, and the positional accuracy can be improved.

In the above invention, the screw shaft and / or
Alternatively, the worm can be configured to be driven by a pulse motor.

In still above invention, a displacement of the movable body due to the rotation of the differential members offset by the rotation of the screw shaft, variable
The distance between the substrate and the movable body when the moving body is not operated can be configured to be kept constant.

The thread pitch p ₁ of the screw shaft and the nut member and the pitch p ₂ of the male differential screw and the female differential screw can be set to satisfy p ₁ > p ₂ .

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a longitudinal sectional front view of an essential part showing an embodiment of the present invention, and FIG. 2 is a sectional plan view of an essential part taken along line AA in FIG. In both figures, reference numeral 1 denotes a substrate, which is formed, for example, in the shape of a rectangular flat plate. For example, columnar guide bars 2 are set up at four corners thereof. A support plate 3 formed in, for example, a rectangular flat plate shape is fixed to an upper end portion of the guide bar 2 via, for example, a fastening member 4.

Reference numeral 5 denotes a screw shaft, which is supported at the center of the support plate 3 via a bearing member 6 so as to be able to rotate forward and backward so as to penetrate the support plate 3. A movable body 7 is engaged with the guide bar 2 so as to be movable in the axial direction. Reference numeral 8 denotes a nut member, which is formed by integrally connecting a nut portion 10 having a flange portion 9 and a cylindrical portion 11 formed in a hollow cylindrical shape. The nut portion 10 is screwed with the screw shaft 5 by ball screw engagement, and a differential male screw 13 is provided on the outer peripheral surface of the cylindrical portion 11.

Reference numeral 14 denotes a differential member, which is formed in a hollow cylindrical shape, and has a female differential screw 15 screwed to the male differential screw 13 on the inner peripheral surface. A worm wheel 16 is integrally fixed to the differential member 14 and is formed so as to engage with the worm 17. Numerals 18 and 19 are a radial bearing and a thrust bearing, respectively, provided in the movable body 7.
Each supports the differential member 14 and the worm wheel 16.

A worm shaft 20 is inserted through and fixed to the center of the worm 17, and both ends are rotatably supported by bearings 21 and 21 provided in the movable body 7. Reference numerals 22 and 23 denote pulse motors, which are provided so as to rotate the screw shaft 5 and the worm shaft 20, respectively. Reference numeral 24 denotes a presser, which is detachably provided on the lower surface of the center of the movable body 7. The pulse motor 22,
Reference numeral 23 is configured to be controllable by applying a predetermined pulse through a control device (not shown). Reference numeral 25 denotes a brake device, which is interposed on the screw shaft 5 and configured to be able to selectively restrict the rotation of the screw shaft 5 via a control device (not shown).

FIG. 3 shows the pressing element 24 shown in FIGS.
FIG. 4 is an explanatory diagram schematically showing the relationship between the position and the pressing force time. The operation will be described below with reference to FIGS.

First, when the pulse motor 22 is operated by applying a predetermined number of pulses, the screw shaft 5 is rotated, the movable body 7 having the nut member 8 is lowered, and the pressing element 24 has an initial height H.
₀ down from (Uetometen) to a height H ₁ of the vicinity of the fixed-point working height H (Shitatometen), the pulse motor 22 in this position
Stops, and the brake device 25 operates to restrict the rotation of the screw shaft 5 and fix the screw shaft 5.

Next, the pulse motor 23 is operated by applying a predetermined number of pulses to rotate the worm shaft 20, the worm 17 and the worm wheel 16, and
By the rotation, the pushing element 24 moves downward from said height H ₁ to fixed-point working height H, in contact with the workpiece W. As a result, the workpiece W is pressed at a predetermined pressing force via the pressing element 24.
Is performed at a fixed point.

[0029] After the processing end, the movable member 7 is raised by the reverse operation of the pulse motor 23 is first, pushing element 24 is raised from the fixed-point working height H to the height H _1, the brake device 25 releases and the pulse motor 22 the reverse operation, the presser 24 returns to the position of the initial height H _0. After the machining is completed, the brake device 25 may be released, the pulse motors 22 and 23 may be simultaneously operated in reverse, and the presser 24 may be returned as shown by the chain line in FIG.

The pressing element 2 when the movable body 7 is lowered
4 applies pressure to the workpiece W by the pulse motor 2
From F ₁ by 2, it increases significantly up to F ₂ by the pulse motor 23. That is, the rotation by the pulse motor 23 is greatly reduced by the reduction ratio between the worm 17 and the worm wheel 16, so that the transmitted torque is increased to the reciprocal multiple of the reduction ratio. As described above, as a result that the pressure applied to the workpiece W can be greatly increased, the pulse motor 23 can have a small capacity.

The movement of the presser 24 from the height H ₁ to the height H in FIG. 3 is caused by the rotation of the worm 17 and the worm wheel 16 in FIGS. Although the operation is performed at a low speed because the screw is engaged with the internal thread 15, since (H ₁ −H), that is, the processing stroke is, for example, about 3 to 5 mm,
The processing time is not extended unnecessarily. On the other hand, when the machining stroke is large, the height H
_If the operation of the pulse motor 23 is started at the position ₂ and the presser 24 is lowered in cooperation with the pulse motor 22, it is helpful to shorten the processing time. The heights H ₀ , H ₁ , H ₂ , and H are measured by measuring means (not shown) and can be controlled in relation to the pulse motors 22 and 23.

[0032] then reaches the number of times the above fixed-point processing is set in advance, the position shown in FIG. 1, i.e. to stop the operation of the pulse motor 22 at the position of the initial height H ₀ of the presser 24, the pulse motor 23 Is applied with a preset number of pulses. Thus, the pulse motor 23 rotates by a predetermined number, and the differential member 14 rotates by a predetermined center angle via the worm shaft 20, the worm 17, and the worm wheel 16. With the rotation of the differential member 14, the nut member 8 is stopped and locked, that is, the differential female screw 15 is rotated with respect to the stopped differential male screw 13, so that the movable body 7 is Displace.

Since the initial height H ₀ of the presser 24 naturally changes due to the displacement of the movable body 7, if the screw shaft 5 is rotated as it is, predetermined fixed-point machining cannot be performed. Therefore, a small number of controlled pulses are applied to the pulse motor 22 to slightly rotate the screw shaft 5 to cancel the displacements of the movable body 7 and the presser 24, and to set the initial height of the presser 24. Then, an operation of keeping H ₀ constant is performed.

The rotation of the screw shaft 5 changes the relative position between the screw shaft 5 and the nut 10. That is, the relative position between the ball and the ball groove formed in the ball screw engagement can be changed, and the local wear of the ball and / or the ball groove can be prevented while securing the fixed point processing. After performing the above correction operation,
The above-mentioned fixed point machining is continued again.

In this case, the screw shaft 5 and the nut member 8
The screw pitch of (nut part 10) is p ₁ and the differential male screw 1
3 and when the pitch of the differential female screw 15 and a p _2,
It is preferable that p ₁ > p ₂ . That is, p ₁ ≦ p
_If it is ₂ , the differential member 14 may be rotated in the opposite direction due to the reaction force when the pressing force is applied to the workpiece W by the pressing element 24, and such an undesired phenomenon is prevented. That's why. In addition, the displacement amount of the movable body 7 due to the rotation of the differential member 14 is kept to a value as small as possible, and it is effective to perform the correction operation easily and quickly.

[0036] For example, 63 mm ball screw outer diameter constituting the screw shaft 5, the thread pitch p ₁ 16 mm, ball diameter 9.5
25mm (3 / 8in.), Diameter between balls center 65.7mm, 1
And ball number 21 per week, in the case where the pitch p ₂ of the differential for the external thread 13 and the differential female screw 15 was 1.6 mm, the screw shaft 5 with respect to one rotation of the differential member 14 The above-described correction operation is completed by rotating 1/10 rotation, that is, 36 °.

In addition to the above, when the ratio of the number of teeth between the worm 17 and the worm wheel 16 is, for example, 1/40, and the worm 17 is rotated four times to rotate the worm wheel 16 and the differential member 14 1/10. In this case, the screw shaft 5 rotates 1/100 rotation, that is, 3.6 °, but the rotation distance on the circumference of the center of the ball becomes 2.06 mm, which also allows the ball and / or ball groove to rotate. It is fully possible to change the relative position with respect to.

In the embodiment of the invention described above, the so-called vertical type in which the substrate 1 and the support plate 3 are arranged in parallel with the horizontal plane and the guide bar 2 connecting them is provided in the vertical direction has been described. The present invention is also applicable to a so-called horizontal type in which the substrate 1 and the support plate 3 are provided in parallel with the vertical plane and the guide bar 2 is provided in the horizontal direction.

Although the embodiment in which the movable body 7 exists above the workpiece W has been described with reference to FIGS. 1 and 2, the movable body 7 may be arranged below the workpiece W. The effect is similar. As a modification of FIGS. 1 and 2, a differential member 14 having a differential male screw 13, a differential female screw 15, a worm 17 and a worm wheel 16 are provided.
May be provided in the substrate 1 to push up the workpiece W from below.

Next, the present invention is particularly effective for the case where the screw shaft 5 and the nut portion 10 constituting the nut member 8 are engaged with a ball screw. It is also applicable. That is, the effect of preventing the local wear due to the application of the reaction force corresponding to the pressing force at the time of processing only to a specific portion of the screw and extending the life can be similarly expected. Of course, it is also possible to use a multi-thread or a multi-thread, including a ball screw engagement.

The pulse motors 22 and 23 for driving the screw shaft 5 and the worm shaft 20 are most commonly configured to be coaxially and directly connected to those shafts, but are transmitted through transmission means such as gears and timing belts. May be configured to transmit power. The worm shaft 20 may be selectively rotated manually. In short, information on the rotation speed of the worm shaft 20 can be controlled by reflecting the information on the number of pulses of the pulse motor 22 for the correction operation. Should be fine.

Although the description has been given of the case where the screw shaft 5 is driven for moving the movable body 7, the screw shaft 5 is fixed,
The nut portion 10 screwed with the screw shaft 5 may be driven by a pulse motor. In this case, the brake device 25 is provided on the nut portion 10, and the servomotor is provided on the movable body. In addition, the brake device 25 for restraining the rotation of the screw shaft 5 or the nut portion 10 is omitted, and the servo motor 2
2, the braking action may be performed.

In the above-described embodiment, the drive motor for the screw shaft 5 and the worm shaft 20 has been described as a pulse motor. However, this drive motor may be any servo motor capable of detecting and controlling the position.

Further, the guide bar 2 for guiding the movement of the movable body 7 is preferably a plurality of guide bars for large ones or those requiring rigidity, but a single bar may be used. Alternatively, the movable body 7 may be formed in a beam shape and the movable body 7 slides or slides along the side surface.

Further, in addition to the single use of the press apparatus of the present invention, it is naturally applicable to a case where a plurality of press machines are arranged in tandem and, for example, a long workpiece is progressively fed. It is possible. In addition, the press device of the present invention, in addition to sheet metal processing on a sheet material, assembling a plurality of parts, press fitting,
It can also be used for processing of caulking and the like, and also for clamping of a molding die in an injection molding machine, die casting, powder metallurgy and the like.

[0046]

Since the present invention has the above-described configuration and operation, the following effects can be obtained. (1) Since the pressure applied to the workpiece or the pressurized body is increased to the reciprocal multiple of the reduction ratio of the worm and the worm wheel, a large pressure is obtained. (2) The motor for driving the pressing element can be of a small capacity, and the driving energy can be greatly reduced. (3) Even if the fixed point processing is continued, the relative position between the screw shaft for pressure application and the nut member can be appropriately changed, so that local wear can be prevented and the service life can be extended. (4) Since the operation for changing the relative position can be performed extremely easily and in a short time, the ratio of actual working time is high, and highly efficient and efficient production is possible. (5) Since the lower end stop position of the movable body can be accurately controlled,
Processing accuracy can be improved. (6) A quiet working environment can be ensured without noise as in the case of the fluid pressure driven type.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a main part showing an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view of a main part taken along line AA in FIG.

FIG. 3 is an explanatory diagram schematically showing a relationship between a position of a pressing element 24 and a pressing time in FIGS. 1 and 2;

FIG. 4 is an explanatory view showing a conventional body stamping process.

FIG. 5 is a longitudinal sectional view of a main part showing an example of a conventional electric press.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Guide bar 3 Support plate 5 Screw shaft 7 Movable body 8 Nut member 13 Differential male screw 14 Differential member 15 Differential female screw 16 Worm wheel 17 Worm 25 Brake device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B30B 1/18 B30B 15/06

Claims (7)

(57) [Claims] 1. A substrate, a support plate provided at a predetermined distance from the substrate, a screw shaft supported to be orthogonal to the support plate and rotatable forward and reverse, and interposed on the screw shaft. A brake device for selectively restricting rotation of the screw shaft, a movable body movably engaged in parallel with the axis of the screw shaft, and provided in the movable body and screwed with the screw shaft. A nut member formed on the outer periphery of the nut member or the differential male screw provided on the substrate,
A differential member formed in a hollow cylindrical shape and having a female differential screw threadedly engaged with the male differential screw on the inner peripheral surface and rotatably formed; And a second gear engaged with the movable member, the rotation of the screw shaft is restricted in the vicinity of the end point of the movement of the movable member, and the rotation of the differential member causes the movable member or a member facing the movable member to rotate. A pressurizing device for moving a pressurizing body to a predetermined moving end point. 2. The pressurizing device according to claim 1, wherein the substrate and the support plate are arranged in parallel with the horizontal plane, and the axis of the screw shaft is arranged in the vertical direction. 3. The pressurizing device according to claim 1, wherein the screw shaft and the nut member are engaged with a ball screw. 4. The pressurizing device according to claim 1, wherein the screw shaft is driven by a pulse motor. 5. The worm according to claim 1, wherein the first gear is formed by a worm, the second gear is formed by a worm wheel, and the worm is driven by a pulse motor. The pressurizing device according to any one of the above. 6. The displacement of the movable body due to the rotation of the differential member is offset by the rotation of the screw shaft, so that the distance between the substrate and the movable body when the movable body is not operated is kept constant. The pressure device according to any one of claims 1 to 5, wherein the pressure device is configured as follows. 7. A screw pitch p of a screw shaft and a nut member.
₁ a pressure device according to the pitch p ₂ of the differential male screw and differential female screw to 6 or claims 1, characterized in that the p _1> p _2.